CN110520493B

CN110520493B - Self-stopping polishing composition and method for bulk oxide planarization

Info

Publication number: CN110520493B
Application number: CN201880025600.XA
Authority: CN
Inventors: A.W.海恩斯; 张柱然; 李常怡; 林越; 崔骥; S.布罗斯南; 南哲祐
Original assignee: CMC Materials LLC
Current assignee: CMC Materials LLC
Priority date: 2017-04-17
Filing date: 2018-03-23
Publication date: 2022-11-22
Anticipated expiration: 2038-03-23
Also published as: KR102671229B1; TW201839077A; CN110520493A; WO2018194792A1; EP3612608A1; KR20190132537A; TWI663231B; JP7132942B2; EP3612608A4; CN113637412A; JP2020517117A

Abstract

The invention provides a chemical-mechanical polishing composition comprising an abrasive, a self-stopping agent, an aqueous carrier, and optionally a cationic polymer, and methods suitable for polishing a substrate.

Description

Self-stopping polishing composition and method for bulk oxide planarization

Background

In the fabrication of integrated circuits and other electronic devices, multiple layers of conductive, semiconductive, and dielectric materials are deposited on or removed from a substrate surface. As layers of material are sequentially deposited on and removed from a substrate, the uppermost surface of the substrate may become non-planar and require planarization. Planarization of a surface or "polishing" of a surface is a process in which material is removed from the surface of a substrate to form a substantially uniformly flat surface. Planarization is useful for removing undesirable surface topography and surface defects such as rough surfaces, agglomerated materials, lattice damage, scratches, and contaminated layers or materials. Planarization is also useful for forming features on substrates by removing excess deposited material used to fill the features and provide a uniform surface to subsequent levels of metallization and processing.

Compositions and methods for planarizing or polishing a substrate surface are known in the art. Chemical mechanical planarization or Chemical Mechanical Polishing (CMP) is a common technique used to planarize substrates. CMP utilizes a chemical composition, referred to as a CMP composition or more simply as a polishing composition (also referred to as a polishing slurry), for selectively removing material from a substrate. Typically, the polishing composition is applied to the substrate by contacting the surface of the substrate with a polishing pad (e.g., a polishing cloth or disk) saturated with the polishing composition. Typically, the polishing of the substrate is further aided by the chemical activity of the polishing composition and/or the mechanical activity of an abrasive suspended in the polishing composition or incorporated into the polishing pad (e.g., a fixed abrasive polishing pad).

As the size of integrated circuits decreases and the number of integrated circuits on a chip increases, the components making up the circuit must be placed closer together in order to conform to the limited space available on a typical chip. Effective isolation between circuits is important to ensure optimal semiconductor performance. To this end, shallow trenches are etched into a semiconductor substrate and filled with an insulating material to isolate the active regions of the integrated circuit. More specifically, shallow Trench Isolation (STI) is a process in which a silicon nitride layer is formed on a silicon substrate, a shallow trench is formed via etching or photolithography, and a dielectric layer is deposited to fill the trench. As the depth of trenches formed in this manner varies, it is typically necessary to deposit an excess of dielectric material on top of the substrate to ensure complete filling of all trenches. The dielectric material (e.g., silicon oxide) conforms to the underlying topography of the substrate.

Thus, after the dielectric material has been deposited, the surface of the deposited dielectric material is characterized by a non-uniform combination of raised regions of dielectric material separated by trenches in the dielectric material, which are aligned with corresponding raised regions and trenches of the underlying surface. The area of the substrate surface comprising raised dielectric material and trenches is referred to as the patterning area of the substrate, e.g. as "patterning material", "patterning oxide" or "patterning dielectric" (dielectric) ". This field of patterning is characterized by a "step height," which is the difference in height of the raised regions of dielectric material relative to the trench height.

Typically, excess dielectric material is removed by CMP methods, which additionally provide a planar surface for further processing. During the process of removing material from the raised region, an amount of material will also be removed from the trench. This removal of material from the trench is referred to as "trench erosion" or "trench depletion". Trench loss is the amount of material (thickness, e.g., in angstroms) removed from the trench when planarization of the patterned dielectric material is achieved by eliminating the initial step height

In units). The trench loss is calculated as the initial trench thickness minus the final trench thickness. Desirably, the rate of material removal from the trenches is much lower than the rate of material removal from the raised regions. Thus, as the material of the raised regions is removed (at a faster rate than the material is removed from the trenches), the patterned dielectric becomes what may be referred to as a "blanket" region of the processing substrate surface, such as a highly planarized surface of "blanket dielectric" or "blanket oxide".

The polishing composition can be characterized in terms of its polishing rate (i.e., removal rate) and its planarization efficiency. Polishing rate refers to the rate at which material is removed from the surface of a substrate and is typically expressed as a unit of length (thickness, e.g., in angstroms) per unit of time (e.g., per minute)

In units). The different removal rates associated with different areas of the substrate or with different stages of the polishing stepIt can be important in assessing the efficacy of a method. The "pattern removal rate" is the rate at which dielectric material is removed from the raised regions of the patterned dielectric layer during the method step in which the substrate exhibits a substantial step height. The "blanket removal rate" refers to the rate at which dielectric material is removed from the planarized (i.e., "blanket") regions of the patterned dielectric layer at the end of the polishing step, at which time the step height has been significantly (e.g., substantially completely) reduced. Planarization efficiency relates to the reduction in step height (i.e., the reduction in step height divided by the trench loss) compared to the amount of material removed from the substrate. In particular, a polishing surface (e.g., a polishing pad) first contacts the "high points" of the surface and material must be removed in order to form a planar surface. Methods that result in a planar surface with less material removed are considered more efficient than methods that require more material to be removed to achieve planarity.

Generally, for a dielectric polishing step in an STI process, the removal rate of a silicon oxide pattern material may be rate-limiting, and thus a high removal rate of a silicon oxide pattern is desired to improve device yield. However, if the blanket removal rate is too fast, over-polishing of the oxide located in the exposed trenches results in trench erosion and increased device defects. If the blanket removal rate is reduced, overpolishing and associated trench loss may be avoided.

It is desirable in certain polishing applications of CMP compositions to exhibit "self-stopping" behavior such that the removal rate is reduced when a large portion of the "high spots" (i.e., raised regions) of the surface have been removed. In self-stop polishing applications, the removal rate is effectively high when a significant step height exists at the substrate surface, and then decreases as the surface effectively becomes planar. In multiple dielectric polishing steps (e.g., of an STI process), the removal rate of patterned dielectric materials (e.g., dielectric layers) is typically the rate-limiting factor in the overall process. Therefore, high removal rates of patterned dielectric materials are desirable to improve throughput. Furthermore, good efficiency in the form of relatively low trench loss is desired. In addition, if the dielectric removal rate is still high after planarization is achieved, overpolishing occurs, resulting in additional trench loss.

The advantage of self-stopping slurries results from a reduced blanket removal rate, which results in a wide endpoint window. For example, the self-stop behavior allows for polishing substrates with reduced dielectric film thickness, allowing for a reduced amount of material to be deposited over the structured underlying layer. In addition, engine torque end point detection may be used to more effectively monitor the final configuration. The substrate may be polished with lower trench loss after planarization by avoiding overpolishing or unnecessary removal of dielectric.

Currently, self-immolative CMP compositions have been developed based on ceria/anionic polyelectrolyte systems. For example, U.S. patent application publication 2008/0121839 discloses a polishing composition comprising an inorganic abrasive, a polyacrylic acid/maleic acid copolymer, and a gemini surfactant. Korean patent No. 10-1524624 discloses a polishing composition comprising cerium oxide, a carboxylic acid and a mixed amine compound (english abstract). International patent application publication No. WO2006/115393 discloses a polishing composition comprising cerium oxide, a hydroxycarboxylic acid, and an amino alcohol. However, as the structure of semiconductor devices becomes more complex and especially as NAND technology changes from 2D to 3D, current self-stopping CMP compositions are challenged by a limited rate of step height reduction caused by electrostatic repulsion between the abrasive and the silicon oxide surface due to the use of anionic polymers.

There remains a need for compositions and methods for chemical mechanical polishing silicon oxide-containing substrates that will provide suitable removal rates while also providing improved planarization efficiency. The invention provides such a polishing composition and method. These and other advantages of the invention, as well as additional features of the invention, will be apparent from the description of the invention provided herein.

Disclosure of Invention

The invention provides chemical-mechanical polishing compositions comprising an abrasive, a self-stop agent, an aqueous carrier, and optionally a cationic compound, and methods suitable for polishing a substrate using the polishing compositions of the invention.

More specifically, the present invention provides a chemical-mechanical polishing composition comprising: (a) an abrasive; (b) A self-stopping agent of formula Q-B, wherein Q can be a substituted or unsubstituted hydrophobic group, or a steric hindrance imparting group, B is a binding group, wherein the binding group has the structure: c (O) -X-OH or-C (O) -OH, wherein X is C1-C2 alkyl; and (c) an aqueous carrier, wherein the polishing composition has a pH of about 3 to about 9.

The invention also provides a chemical-mechanical polishing composition comprising: (a) an abrasive comprising cerium oxide (ceria); (b) a self-stopping agent selected from the group consisting of: kojic acid (5-hydroxy-2- (hydroxymethyl) -4H-pyran-4-one), crotonic acid ((E) -2-butenoic acid), tiglic acid ((2E) -2-methylbut-2-enoic acid), valeric acid (valeric acid/pentanoic acid), 2-pentenoic acid, maltol (3-hydroxy-2-methyl-4H-pyran-4-one), benzoic acid, 3, 4-dihydroxybenzoic acid, 3, 5-dihydroxybenzoic acid, caffeic acid, ethyl maltol, potassium sorbate, sorbic acid, and combinations thereof; and (c) an aqueous carrier, wherein the polishing composition has a pH of about 3 to about 9.

The invention also provides a chemical-mechanical polishing composition comprising:

(a) An abrasive comprising cerium oxide (ceria);

(b) A self-stopping agent selected from the group consisting of:

a compound of formula (I):

wherein R is selected from: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocycloaryl, each of which may be substituted or unsubstituted;

a compound of formula (II):

wherein X ¹ To X ³ Each independently selected from N, O, S, sp ² Hybrid carbon and CY ¹ Y ² In which Y is ¹ And Y ² Each independently selected from hydrogen, hydroxy, C ₁ -C ₆ Alkyl, halogen and combinations thereof, and Z ¹ -Z ³ Each independently selected from hydrogen, hydroxy, C ₁ -C ₆ Alkyl and combinations thereof, each of which may be substituted or unsubstituted;

a compound of formula (III):

Z-(C(X ¹ X ² ) _n ) _p -CO ₂ M(III)，

wherein Z is selected from C ₁ -C ₆ Alkyl radical, C ₁ -C ₆ Alkenyl radical, C ₁ -C ₆ Alkynyl and aryl groups (e.g., phenyl, benzyl, naphthyl, azulene, anthracene, pyrene, etc.), X ¹ And X ² Independently selected from hydrogen, hydroxy, amino and C ₁ -C ₆ Alkyl, and wherein X taken together with the carbon to which it is attached ¹ And X ² Can form sp ² Hybrid carbon, n is 1 or 2, p is 0 to 4, and M is selected from hydrogen and a suitable counter ion (e.g., a group I metal), each of which may be substituted or unsubstituted; and combinations thereof;

a compound of formula (IV):

wherein X, Y and Z are independently selected from H, O, S, NH and CH ₂ ，R ¹ 、R ² And R ³ Independently selected from H, alkyl, alkenyl, alkynyl, aryl, halo (halo), and haloalkyl, and M is selected from hydrogen and a suitable counterion;

(c) Optionally a cationic polymer; and

(d) An aqueous carrier, a water-based vehicle,

wherein the polishing composition has a pH of about 3 to about 9.

The invention further provides a method of chemically-mechanically polishing a substrate comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of dielectric material (e.g., an active region relative to a surrounding (peri) region), and wherein an initial step height of the patterned dielectric layer describes a thickness range of the oxide (e.g., an active thickness range relative to a surrounding thickness range); (ii) providing a polishing pad; (iii) Providing a chemical-mechanical polishing composition as described herein; (iv) Contacting a substrate with a polishing pad and a chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer located on the surface of the substrate, thereby polishing the substrate.

Drawings

Fig. 1 (not to scale) shows a cross-sectional view of an example substrate to illustrate active regions, trench regions, step heights, and trench losses.

FIG. 2 depicts the polishing performance of the polishing composition of the invention as a function of the pitch width and pattern density of a substrate.

Detailed Description

The invention provides a chemical-mechanical polishing composition comprising: (a) an abrasive; (b) A self-stopping agent of formula Q-B, wherein Q can be a substituted or unsubstituted hydrophobic group, or a steric hindrance imparting group, B is a binding group, wherein the binding group has the structure: c (O) -X-OH or-C (O) -OH, wherein X is C1-C2 alkyl; and (c) an aqueous carrier, wherein the polishing composition has a pH of about 3 to about 9.

The polishing composition of the invention comprises an abrasive. The abrasive of the polishing composition desirably is suitable for polishing non-metallic portions of a substrate (e.g., patterned dielectric material, blanket dielectric material, patterned oxide material, blanket oxide material, etc.). Suitable abrasives include cerium oxide (ceria) (e.g., ceO) ₂ ) Zirconium oxide (zirconia) (e.g., zrO) ₂ ) Silicon oxide (silicon oxide) (e.g. SiO) ₂ ) And combinations thereof.

In a preferred embodiment, the abrasive is selected from the group consisting of ceria, zirconia, and combinations thereof. In another preferred embodiment, the abrasive is cerium oxide.

Both ceria and zirconia abrasives are well known and commercially available in the CMP art. Examples of suitable ceria abrasives include wet-process ceria, calcined ceria, metal-doped ceria, and the like. Examples of suitable zirconia abrasives include metal doped zirconia, non-metal doped zirconia, and the like. Among the metal doped zirconia is cerium, calcium, magnesium or yttrium doped zirconia having a dopant element weight percent preferably in the range of 0.1-25%.

Ceria abrasives suitable for use in the Polishing Compositions of the invention and Methods of making the same are described in U.S. patent application No. 14/639,564, entitled "Polishing Composition connecting ceramic Abrasive," filed 3/5/2015 (now U.S. patent No. 9,505,952) and U.S. patent application No. 15/207,973, entitled "Methods and Compositions for Processing Dielectric Substrate," filed 12/7/2016 (published as U.S. patent application publication No. 2017/0014969), the disclosures of each of which are incorporated herein by reference.

The preferred abrasive is wet-process ceria particles. The polishing composition can comprise a single type of abrasive particle or a plurality of different types of abrasive particles based on size, composition, method of preparation, particle size distribution, or other mechanical or physical properties. The cerium oxide abrasive particles can be prepared by a variety of different methods. For example, the ceria abrasive particles can be precipitated ceria particles or condensation-polymerized ceria particles, including colloidal ceria particles.

The ceria abrasive particles can be made by any suitable method. As an example, the cerium oxide abrasive particles may be wet-process cerium oxide particles prepared according to the following method. Typically, the first step in synthesizing wet-process ceria particles is to dissolve a ceria precursor in water. The ceria precursor can be any suitable ceria precursor and can include a ceria salt having any suitable charge, e.g., ce ³⁺ Or Ce ⁴⁺ . Suitable ceria precursors include, for example, cerium III nitrate, ammonium cerium IV nitrate, cerium III carbonate, cerium IV sulfate, and cerium III chloride. Preferably, the cerium oxide precursor is cerium III nitrate.

Typically, the pH of the ceria precursor solution is increased to form amorphous Ce (OH) ₃ . The pH of the solution may be increased to any suitable pH. For example,the pH of the solution may be increased to a pH of about 10 or higher, for example a pH of about 10.5 or higher, a pH of about 11 or higher, or a pH of about 12 or higher. Typically, the solution will have a pH of about 14 or less, for example a pH of about 13.5 or less, or a pH of about 13 or less. Any suitable base may be used to increase the pH of the solution. Suitable bases include, for example, KOH, naOH, NH ₄ OH and tetramethylammonium hydroxide. Organic bases such as ethanolamine and diethanolamine are also suitable. With increasing pH and amorphous Ce (OH) ₃ The solution will become white and turbid.

The ceria precursor solution is typically mixed for several hours. For example, the solution can be mixed for about 1 hour or more, e.g., about 2 hours or more, about 4 hours or more, about 6 hours or more, about 8 hours or more, about 12 hours or more, about 16 hours or more, about 20 hours or more, or about 24 hours or more. Typically, the solution is mixed for about 1 hour to about 24 hours, e.g., about 2 hours, about 8 hours, or about 12 hours. When mixing is complete, the solution can be transferred to a pressurized vessel and heated.

The ceria precursor solution can be heated to any suitable temperature. For example, the solution can be heated to a temperature of about 50 ℃ or higher, such as about 75 ℃ or higher, about 100 ℃ or higher, about 125 ℃ or higher, about 150 ℃ or higher, about 175 ℃ or higher, or about 200 ℃ or higher. Alternatively, or in addition, the solution may be heated to a temperature of about 500 ℃ or less, e.g., about 450 ℃ or less, about 400 ℃ or less, about 375 ℃ or less, about 350 ℃ or less, about 300 ℃ or less, about 250 ℃ or less, about 225 ℃ or about 200 ℃ or less. Thus, the solution can be heated to a temperature within a range defined by any two of the aforementioned endpoints. For example, the solution can be heated to a temperature of about 50 ℃ to about 300 ℃, such as about 50 ℃ to about 275 ℃, about 50 ℃ to about 250 ℃, about 50 ℃ to about 200 ℃, about 75 ℃ to about 300 ℃, about 75 ℃ to about 250 ℃, about 75 ℃ to about 200 ℃, about 100 ℃ to about 300 ℃, about 100 ℃ to about 250 ℃, or about 100 ℃ to about 225 ℃.

The ceria precursor solution is typically heated for several hours. For example, the solution can be heated for about 1 hour or more, such as about 5 hours or more, about 10 hours or more, about 25 hours or more, about 50 hours or more, about 75 hours or more, about 100 hours or more, or about 110 hours or more. Alternatively, or in addition, the solution may be heated for about 200 hours or less, such as about 180 hours or less, about 165 hours or less, about 150 hours or less, about 125 hours or less, about 115 hours or less, or about 100 hours or less. Thus, the solution may be heated for a period of time defined by any two of the aforementioned endpoints. For example, the solution may be heated for about 1 hour to about 150 hours, such as about 5 hours to about 130 hours, about 10 hours to about 120 hours, about 15 hours to about 115 hours, or about 25 hours to about 100 hours.

After heating, the cerium oxide precursor solution may be filtered to isolate precipitated cerium oxide particles. The precipitate may be rinsed with excess water to remove unreacted ceria precursor. The mixture of precipitate and excess water can be filtered after each washing step to remove impurities. Once sufficiently rinsed, the cerium oxide particles may be dried for additional processing (e.g., sintering), or alternatively, the cerium oxide particles may be directly redispersed.

Optionally, the cerium oxide particles may be dried and sintered prior to redispersion. The terms "sintering" and "calcining" are used interchangeably herein to refer to heating cerium oxide particles under the conditions described below. Sintering the ceria particles affects their resulting crystallinity. Without wishing to be bound by any particular theory, it is believed that sintering the ceria particles at a high temperature for an extended period of time reduces defects in the lattice structure of the particles. Any suitable method may be used to sinter the cerium oxide particles. As an example, the cerium oxide particles may be dried and then sintered at an elevated temperature. Drying can be carried out at room temperature or at elevated temperature. Specifically, drying may be carried out at a temperature of about 20 ℃ to about 40 ℃, e.g., about 25 ℃, about 30 ℃, or about 35 ℃. Alternatively, or in addition, drying may be carried out at an elevated temperature of about 80 ℃ to about 150 ℃, e.g., about 85 ℃, about 100 ℃, about 115 ℃, about 125 ℃, or about 140 ℃. After the cerium oxide particles have been dried, they may be milled to form a powder. Milling may be carried out using any suitable milling material, such as zirconia.

The cerium oxide particles may be sintered in any suitable oven and at any suitable temperature. For example, the cerium oxide particles may be sintered at a temperature of about 200 ℃ or higher, e.g., about 215 ℃ or higher, about 225 ℃ or higher, about 250 ℃ or higher, about 275 ℃ or higher, about 300 ℃ or higher, about 350 ℃ or higher, or about 375 ℃ or higher. Alternatively, or in addition, the ceria particles can be sintered at a temperature of about 1000 ℃ or less, such as about 900 ℃ or less, about 750 ℃ or less, about 650 ℃ or less, about 550 ℃ or less, about 500 ℃ or less, about 450 ℃ or less, or about 400 ℃ or less. Thus, the cerium oxide particles may be sintered at a temperature defined by any two of the aforementioned endpoints. For example, the cerium oxide particles may be sintered at a temperature of about 200 ℃ to about 1000 ℃, such as about 250 ℃ to about 800 ℃, about 300 ℃ to about 700 ℃, about 325 ℃ to about 650 ℃, about 350 ℃ to about 600 ℃, about 350 ℃ to about 550 ℃, about 400 ℃ to about 550 ℃, about 450 ℃ to about 800 ℃, about 500 ℃ to about 1000 ℃, or about 500 ℃ to about 800 ℃.

The cerium oxide particles may be sintered for any suitable length of time. For example, the cerium oxide particles may be sintered for about 1 hour or more, such as about 2 hours or more, about 5 hours or more, or about 8 hours or more. Alternatively, or in addition, the cerium oxide particles may be sintered for about 20 hours or less, for example, about 18 hours or less, about 15 hours or less, about 12 hours or less, or about 10 hours or less. Thus, the cerium oxide particles may be sintered for a period of time defined by any two of the aforementioned endpoints. For example, the cerium oxide particles may be sintered for about 1 hour to about 20 hours, such as about 1 hour to about 15 hours, about 1 hour to about 10 hours, about 1 hour to about 5 hours, about 5 hours to about 20 hours, or about 10 hours to about 20 hours.

The cerium oxide particles may also be sintered at various temperatures and for various lengths of time within the ranges described above. For example, the cerium oxide particles may be sintered in a zonefurance furnace, which exposes the cerium oxide particles to one or more temperatures for various lengths of time. As an example, the cerium oxide particles may be sintered at a temperature of about 200 ℃ to about 1000 ℃ for about 1 hour or more, and then, may be sintered at a different temperature in the range of about 200 ℃ to about 1000 ℃ for about 1 hour or more.

Typically, the cerium oxide particles are redispersed in a suitable carrier (e.g., an aqueous carrier, especially water). If the cerium oxide particles are sintered, the cerium oxide particles are redispersed after the sintering is completed. Any suitable method can be used to redisperse the cerium oxide particles. Typically, the cerium oxide particles are redispersed by lowering the pH of a mixture of the cerium oxide particles and water using a suitable acid. As the pH decreases, the surface of the cerium oxide particles develops a cationic zeta potential. The cationic zeta potential creates a repulsive force between the cerium oxide particles, which facilitates redispersion of the cerium oxide particles. Any suitable acid may be used to lower the pH of the mixture. Suitable acids include, for example, hydrochloric acid and nitric acid. Organic acids that are highly water soluble and have hydrophilic functional groups are also suitable. Suitable organic acids include, for example, acetic acid. Acids having polyvalent anions (such as H) ₃ PO ₄ And H ₂ SO ₄ ) And are generally not preferred. The pH of the mixture can be lowered to any suitable pH. For example, the pH of the mixture may be lowered to about 2 to about 5, such as about 2.5, about 3, about 3.5, about 4, or about 4.5. Typically, the pH of the mixture does not drop below about 2.

Typically, the redispersed cerium oxide particles are milled to reduce their particle size. Preferably, the cerium oxide particles are milled while redispersing. Milling may be carried out using any suitable milling material, such as zirconia. Milling can also be carried out using sonication or wet spray procedures. After milling, the ceria particles can be filtered to remove any remaining large particles. For example, the cerium oxide particles may be filtered using a filter having a pore size of about 0.3 μm or greater, such as about 0.4 μm or greater or about 0.5 μm or greater.

The median particle size of the abrasive particles (e.g., cerium oxide abrasive particles) is preferably from about 40nm to about 100nm. The particle size of a particle is the diameter of the smallest sphere that surrounds the particle. The particle size of the abrasive particles can be measured using any suitable technique. For example, the particle size of the abrasive particles may be measured using a disk centrifuge, i.e., by Differential Centrifugal Settling (DCS). Suitable disk centrifuge particle size measuring Instruments are available from, for example, CPS Instruments (Prairieville, la.), for example, CPS disk centrifuge model DC24000 UHR. Unless otherwise specified, the median particle size values reported and claimed herein are based on disk centrifuge measurements.

By way of example, the median particle diameter of the abrasive particles (e.g., cerium oxide abrasive particles) can be about 40nm or greater, such as about 45nm or greater, about 50nm or greater, about 55nm or greater, about 60nm or greater, about 65nm or greater, about 70nm or greater, about 75nm or greater, or about 80nm or greater. Alternatively, or in addition, the abrasive particles can have a median particle size of about 100nm or less, e.g., about 95nm or less, about 90nm or less, about 85nm or less, about 80nm or less, about 75nm or less, about 70nm or less, or about 65nm or less. Thus, the median particle diameter of the abrasive particles can be within a range defined by any two of the aforementioned endpoints. For example, the median particle size of the abrasive particles can be about 40nm to about 100nm, e.g., about 40nm to about 80nm, about 40nm to about 75nm, about 40nm to about 60nm, about 50nm to about 100nm, about 50nm to about 80nm, about 50nm to about 75nm, about 50nm to about 70nm, about 60nm to about 100nm, about 60nm to about 80nm, about 60nm to about 85nm, or about 65nm to about 75nm. Preferably, the abrasive particles have a median particle size of about 60nm to about 80nm, for example, a median particle size of about 65nm, a median particle size of about 70nm, or a median particle size of about 75nm.

The chemical-mechanical polishing composition can comprise any suitable amount of abrasive. If the composition includes too little abrasive, the composition may not exhibit a sufficient removal rate. In contrast, if the polishing composition comprises too much abrasive, the composition may exhibit undesirable polishing performance, may be not cost effective, and/or may lack stability. Thus, the abrasive can be present in the polishing composition at a concentration of about 5 wt.% or less, e.g., about 4 wt.% or less, about 3 wt.% or less, about 2 wt.% or less, or about 1 wt.% or less. Alternatively, or in addition, the abrasive can be present in the polishing composition at a concentration of about 0.001 wt.% or more, e.g., about 0.005 wt.% or more, about 0.01 wt.% or more, about 0.05 wt.% or more, about 0.1 wt.% or more, or about 0.5 wt.% or more. Thus, the abrasive can be present in the polishing composition at a concentration defined by any two of the aforementioned endpoints. For example, the abrasive can be present in the polishing composition at a concentration of about 0.001 wt.% to about 5 wt.%, e.g., about 0.005 wt.% to about 4 wt.%, about 0.01 wt.% to about 3 wt.%, about 0.05 wt.% to about 2 wt.%, or about 0.1 wt.% to about 1 wt.%.

Typically, the polishing composition does not contain a significant amount of abrasive suitable for polishing metals (e.g., copper, silver, tungsten, etc.) on the surface of the substrate. For example, polishing compositions typically do not contain substantial amounts of the particular metal oxides (e.g., alumina) suitable for polishing metal surfaces. Typically, the polishing composition comprises less than 0.1 wt.% of an abrasive other than a ceria abrasive and a zirconia abrasive, based on the total weight of abrasives in the polishing composition. For example, the polishing composition can comprise about 0.05 wt.% or less of an abrasive other than a ceria abrasive and a zirconia abrasive, or about 0.01 wt.% or less of an abrasive other than a ceria abrasive and a zirconia abrasive. More specifically, the polishing composition can comprise about 0.05 wt.% or less of a metal oxide other than ceria and zirconia, or about 0.01 wt.% or less of a metal oxide other than ceria and zirconia.

Desirably, the abrasive is suspended in the polishing composition, more specifically, in the aqueous carrier of the polishing composition. More specifically, where the abrasive comprises particles, the abrasive particles desirably are suspended in the polishing composition, and the abrasive particles preferably are colloidally stable. The term colloid refers to the suspension of abrasive particles in the aqueous carrier. Colloidal stability refers to the maintenance of the suspension over time. In the context of this invention, abrasive particles are considered colloidally stable if, when the abrasive particles are placed into a 100mL graduated cylinder and allowed to stand unagitated for a time of 2 hours, the difference between the concentration of particles in the bottom 50mL of the graduated cylinder ([ B ] in terms of g/mL) and the concentration of particles in the top 50mL of the graduated cylinder ([ T ] in terms of g/mL) divided by the initial concentration of particles in the abrasive composition ([ C ] in terms of g/mL) is less than or equal to 0.5 (i.e., { [ B ] - [ T ] }/[ C ] ≦ 0.5). Desirably, the value of [ B ] - [ T ]/[ C ] is less than or equal to 0.3 and preferably less than or equal to 0.1.

The polishing composition of the invention comprises a self-stopping agent. The self-stop agent is a compound that facilitates a relatively high pattern removal rate and a relatively low blanket removal rate and that facilitates a transition from a high pattern removal rate to a relatively low blanket removal rate upon planarization during polishing. Without wishing to be bound by any particular theory, it is believed that the self-stopping agent acts as a ligand attached to the abrasive (e.g., to ceria or to zirconia) to promote self-stopping behavior by providing steric hindrance between the abrasive and the hydrophilic oxide surface. The binding of the self-stopping agent to the abrasive can be evaluated using any suitable technique, such as Isothermal Titration Calorimetry (ITC).

Without wishing to be bound by any particular theory, it is believed that the self-stop agent promotes a non-linear response for a given Downforce (DF) on a Tetraethoxysilane (TEOS) blanket dielectric material. During polishing, the patterned dielectric material is subjected to an effective downforce that is higher than the Downforce (DF) of the blanket dielectric material, because the contact is spread only over some portions of the patterned dielectric material that are in contact with the pad. The higher effective DF applied to TEOS patterned dielectric material yields a TEOS removal rate of about

A "high" removal rate (e.g., pattern removal rate), wherein a lower effective DF yields a TEOS removal rate of about

Or a lower (e.g., blanket removal rate) state of "stop" polishing. The difference between the "high" state and the "stop" state is typically significant,such that a "high" removal rate or "stop" removal rate is observed for a given DF. Thus, it is believed that the self-stop agent is desirably capable of achieving a "high" removal rate (i.e., pattern removal rate) even when the applied DF is in a "stop" state as determined with the blanket wafer.

Furthermore, it should also be noted that the mechanism does not depend solely on DF, since the trench oxide removal rate is higher on the patterned dielectric material than the blanket removal rate, even with a smaller effective DF in the trenches than on the blanket wafer. For example, in some polishing applications, the concentration of the self-stop agent plays a role in the observed effect, since at low concentrations, the self-stop agent can act as a rate enhancer (e.g., a "high" removal rate is observed), and at higher concentrations, self-stop behavior is observed (e.g., a "stop" removal rate is observed). Thus, some rate enhancers may have a dual effect. By way of example, picolinic acid can act as a rate enhancer when the polishing composition comprises a lower concentration of picolinic acid (picolinic acid). However, picolinic acid can act as a self-stopping agent when the polishing composition comprises a higher concentration of picolinic acid. Typically, picolinic acid acts as a rate enhancer at a concentration of less than about 1000ppm by weight (e.g., about 500ppm, about 250ppm, etc.).

In some embodiments of the invention, the self-stopping agent has the formula Q-B, wherein Q is a substituted or unsubstituted hydrophobic group, or a steric hindrance imparting group, and B is a binding group, such as-C (O) -C-OH, -C (O) -C-C-OH or-C (O) -OH. For example, in some embodiments, the invention provides a polishing composition comprising an abrasive, a self-stopping agent of the formula Q-B, a cationic compound, and an aqueous carrier (e.g., water), wherein the pH of the polishing composition is about 3 to about 9 (e.g., about 6.5 to about 8.5).

In some embodiments of the invention, the self-stopping agent has the formula Q-B, wherein Q is a substituted or unsubstituted hydrophobic group, or a steric-conferring group, and B is a binding group, wherein the binding group has the structure: -C (O) -X-OH or-C (O) -OH. Wherein X is a C1-C2 alkyl group. When the self-stopping agent is a compound of formula Q-B as described herein, Q can be any suitable hydrophobic group, or any suitable group that imparts steric hindrance. Suitable hydrophobic groups include saturated and unsaturated hydrophobic groups. The hydrophobic groups may be linear or branched, and may include linear or branched alkyl, cycloalkyl, and ring structures, including aromatic, heterocyclic, and fused ring systems.

In an embodiment, Q is selected from the group consisting of alkyl, cycloalkyl, aromatic, heterocyclic, heteroaromatic, and combinations thereof.

Q may be alkyl. Suitable alkyl groups include, for example, straight or branched, saturated or unsaturated, substituted or unsubstituted hydrocarbon groups having from 1 to 30 carbon atoms (e.g., C ₁ -C ₃₀ Alkyl radical, C ₁ -C ₂₄ Alkyl radical, C _l -C ₁₈ Alkyl radical, C ₁ -C ₁₂ Alkyl or even C ₁ -C ₆ Alkyl), for example, having at least 1 carbon atom (i.e., methyl), at least 2 carbon atoms (e.g., ethyl, vinyl), at least 3 carbon atoms (e.g., propyl, isopropyl, propenyl, etc.), at least 4 carbon atoms (butyl, isobutyl, sec-butyl, butane, etc.), at least 5 carbon atoms (pentyl, isopentyl, sec-pentyl, neopentyl, etc.), at least 6 carbon atoms (hexyl, etc.), at least 7 carbon atoms, at least 8 carbon atoms, at least 9 carbon atoms, at least 10 carbon atoms, at least 11 carbon atoms, at least 12 carbon atoms, at least 13 carbon atoms, at least 14 carbon atoms, at least 15 carbon atoms, at least 16 carbon atoms, at least 17 carbon atoms, at least 18 carbon atoms, at least 19 carbon atoms, at least 20 carbon atoms, at least 25 carbon atoms, or at least 30 carbon atoms.

Substituted groups refer to groups in which one or more carbon-bonded hydrogens are replaced with a non-hydrogen atom. Illustrative substituents include, for example, hydroxy, keto, ester, amide, halo (e.g., fluoro, chloro, bromo, and iodo), amino (primary, secondary, tertiary, and/or quaternary amino), and combinations thereof.

Q may be cycloalkyl. Suitable cycloalkyl groups include, for example, saturated or unsaturated, substituted or unsubstituted cycloalkyl groups having from 3 to 20 carbon atoms (e.g., C) ₃ -C ₂₀ Cyclic group). Lifting deviceFor example, suitable cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and combinations thereof. Additionally, suitable unsaturated cycloalkyl groups include, for example, cyclobutene, cyclopentene, cyclohexene, and combinations thereof.

Q may be an aromatic group. Suitable aromatic groups include, for example, substituted or unsubstituted aromatic groups having from 1 to 20 carbon atoms. Suitable aromatic groups include, for example, phenyl, benzyl, naphthyl, azulene, anthracene, pyrene, and combinations thereof.

Q may be a heteroaromatic group. "heteroatom" is defined herein as any atom other than carbon and hydrogen atoms. Suitable heteroatom-containing functional groups include, for example, hydroxyl groups, carboxylic acid groups, ester groups, ketone groups, amino groups (e.g., primary, secondary, and tertiary amino groups), amide groups, imino groups, thiol ester groups, thioether groups, nitrile groups, nitro groups, halogen groups, and combinations thereof.

Suitable heterocyclic groups include, for example, cyclic hydrocarbon compounds containing 1 to 20 carbon atoms and containing nitrogen, oxygen, sulfur, phosphorus, boron, and combinations thereof. Heterocyclic compounds may be saturated and unsaturated, substituted or unsubstituted. Heterocyclic compounds are compounds having one or more 5-, 6-or 7-membered rings containing one or more heteroatoms, such as N, O, S, P or B, which are included as part of the ring system. Illustrative heterocyclic compounds include, for example, triazole, aminotriazole, 3-amino-1, 2, 4-triazole-5-carboxylic acid, 3-amino-5-mercapto-1, 2, 4-triazole, 4-amino-5-hydrazino-1, 2, 4-triazole-3-thiol, thiazole, 2-amino-5-methylthiazole, 2-amino-4-thiazoleacetic acid, heterocyclic N-oxides, 2-hydroxypyridine-N-oxide, 4-methylmorpholine-N-oxide, picolinic acid N-oxide, and the like. Other illustrative heterocyclic compounds include, for example, pyrone compounds, pyridine compounds (including positional isomers and stereoisomers), pyrrolidines, delta-2-pyrrolines, imidazolidines (imidazolidines), delta-2-imidazolines, delta-3-pyrazolines, pyrazolidines (pyrazolidines), piperidines, piperazines, morpholines, quinuclidines, indolines, isoindolines, chromans (chromans), isochromans, and combinations thereof.

Suitable heteroaromatic groups include, for example, pyridine, thiophene, furan,Pyrrole, 2H-pyrrole, imidazole, pyrazole, iso

Oxazole, furazan, isothiazole, pyran (2H), pyrazine, pyrimidine, pyridazine, isobenzofuran, indolizine, indole, 3H-indole, 1H-indazole, purine, isoindole, 4 aH-carbazole, beta-carboline, 2H-benzopyran, 4H-quinolizine, isoquinoline, quinoline, quinoxaline, 1, 8-naphthyridine, phthalazine, quinazoline, cinnoline, pteridine, xanthene, thiophene

Thia, phenothiazine, phenazine, perimidine (perimidine), 1, 7-phenanthroline (phenantroline), phenanthridine, acridine, and combinations thereof.

In some embodiments, Q is substituted with one or more substituents. Suitable substituents may include, for example, any suitable compounds/groups described herein. For example, suitable substituents include alkyl, cycloalkyl, aryl, heterocyclyl, heteroaromatic, and combinations thereof.

In some embodiments, Q is unsubstituted. In other embodiments, Q is a steric-imparting group. For example, Q may not be particularly hydrophobic, but may be a bulky component that prevents chemical reactions or interactions that would otherwise occur with smaller Q groups in the molecule of interest. Without limitation, examples of self-stoppers having such Q groups would be maltol, ethyl maltol, and kojic acid.

In some embodiments, the binding group B is selected from the group consisting of a carboxylic acid group, a hydroxamic acid group, a hydroxylamine group, a hydroxyl group, a ketone group, a sulfate group, a phosphate group, and combinations thereof.

In some embodiments, the self-immobilizer Q-B is selected from the group consisting of kojic acid, maltol, ethyl maltol, propyl maltol, hydroxamic acid, phenylhydroxamic acid, salicylhydroxamic acid, benzoic acid, 3, 4-dihydroxybenzoic acid, 3, 5-dihydroxybenzoic acid, caffeic acid, sorbic acid, and combinations thereof.

In addition, salts of the self-immobilizers of formulation Q-B are also suitable for use in the polishing compositions of the invention.

In some embodiments, the self-stopping agent is selected from the group consisting of kojic acid, maltol, ethyl maltol, propyl maltol, tiglic acid, angelic acid, benzoic acid, 3, 4-dihydroxybenzoic acid, 3, 5-dihydroxybenzoic acid, caffeic acid, sorbic acid, potassium sorbate, and combinations thereof.

In some embodiments, the self-stop agent of formulation Q-B is selected from the group consisting of a compound of formula (I), a compound of formula (II), a compound of formula (III), a compound of formula (IV), and combinations thereof.

The compounds of formula (I) have the following structure:

wherein R is selected from: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocycloaryl, each of which may be substituted or unsubstituted.

The compound of formula (II) has the following structure:

wherein X ¹ To X ³ Each independently selected from N, O, S, sp ² Hybrid carbon and CY ¹ Y ² Wherein Y is ¹ And Y ² Each independently selected from hydrogen, hydroxy, C ₁ -C ₆ Alkyl, halogen and combinations thereof, and Z ¹ To Z ³ Each independently selected from hydrogen, hydroxy, C ₁ -C ₆ Alkyl groups and combinations thereof, each of which may be substituted or unsubstituted.

The compound of formula (III) has the following structure:

Z-(C(X ¹ X ² ) _n ) _p -CO ₂ M(III)，

wherein Z is selected from N, C ₁ -C ₆ Alkyl radical, C ₁ -C ₆ Alkenyl radical, C ₁ -C ₆ Alkynyl and aryl groups (e.g., phenyl, benzyl, naphthyl, azulene, anthracene, pyrene, etc.), X ¹ And X ² Independent of each otherIs selected from hydrogen, hydroxy, amino and C ₁ -C ₆ Alkyl radical, C ₁ -C ₆ An alkenyl group; and wherein X is bonded to the attached carbon ¹ And X ² Can form sp ² Hybrid carbon, n is 1 or 2, p is 0 to 4, and M is selected from hydrogen and a suitable counter ion (e.g., a group I metal), each of which may be substituted or unsubstituted.

The compound of formula (IV) has the following structure:

wherein X, Y and Z are independently selected from H, O, S, NH and CH ₂ ，R ¹ 、R ² And R ³ Independently selected from H, alkyl, alkenyl, alkynyl, aryl, halo, and haloalkyl, and M is selected from hydrogen and a suitable counterion.

The polishing composition can comprise any suitable amount of a self-stopping agent (e.g., a compound of formula Q-B). If the composition comprises too little of a self-stopping agent, the composition may not exhibit suitable self-stopping behavior. In contrast, if the polishing composition includes too much self-stop agent, the composition may exhibit undesirable polishing performance, may not be cost-effective, and/or may lack stability. Thus, the polishing composition can comprise about 2 wt.% or less, e.g., about 1 wt.% or less, about 0.5 wt.% or less, about 0.1 wt.% or less, or about 0.01 wt.% or less of the self-stopping agent. Alternatively, or in addition, the polishing composition can comprise about 0.0001 wt.% or more, e.g., about 0.0005 wt.% or more, about 0.001 wt.% or more, about 0.005 wt.% or more, about 0.01 wt.% or more, or about 0.05 wt.% or more, of the self-stopping agent. Thus, the polishing composition can comprise a self-stop agent in a concentration defined by any two of the aforementioned endpoints. For example, the self-stopping agent can be present in the polishing composition at a concentration of about 0.0001 wt.% to about 2 wt.%, e.g., about 0.0005 wt.% to about 1 wt.%, about 0.001 wt.% to about 0.5 wt.%, about 0.005 wt.% to about 0.1 wt.%, or about 0.01 wt.% to about 0.05 wt.%.

In some embodiments, the inventive polishing composition comprises about 0.5 wt.% or less (e.g., about 5,000ppm or less) of a self-stop agent. In some embodiments, the polishing composition comprises about 2,500ppm (0.25 wt.%) or less, for example about 2,000ppm or less, about 1,500ppm or less, about 1,000ppm or less, or about 500ppm or less of a self-stopping agent.

In some embodiments, the inventive polishing composition comprises a self-stopping agent, also known as a topography control agent, in combination with a planarizing agent (i.e., a cationic compound). Without wishing to be bound by any particular theory, it is believed that the cationic compound acts as a planarizing agent to improve the topography of the polished substrate, as the cationic compound typically reduces the oxide removal rate by binding to negatively charged oxide surfaces. The cationic compound also improves planarization efficiency of the self-stopping composition under higher pH polishing conditions (e.g., having a pH of about 6.5 to about 8.5, having a pH of about 7.0 to 8.5).

The cationic compound can be a polymer comprising a monomer selected from the group consisting of quaternary amines, cationic polyvinyl alcohols, cationic celluloses, and combinations thereof. Thus, the cationic polymer may comprise a quaternary amine, a cationic polyvinyl alcohol, a cationic cellulose, and combinations thereof.

Suitable quaternary amine monomers include, for example, vinylimidazolium, methacryloyloxyethyltrimethylammonium halide, diallyldimethylammonium halide, and combinations thereof. Thus, suitable cationic polymers include, for example, quaternary amines selected from: poly (vinylimidazolium); poly (methacryloxyethyltrimethylammonium) halides, such as poly (methacryloxyethyltrimethylammonium) chloride (poly maduat); poly (diallyldimethylammonium) halides, such as poly (diallyldimethylammonium) chloride (poly DADMAC); poly [ bis (2-chloroethyl) ether-alt-1, 3-bis [3- (dimethylamino) propyl ] ether]Urea](i.e., polyquaternium-2); copolymers of vinylpyrrolidone and quaternized dimethylaminoethyl methacrylate (i.e., polyquaternium-11); copolymers of vinylpyrrolidone and quaternized vinylimidazole (i.e., polyquaternium-16); terpolymers of vinyl caprolactam, vinyl pyrrolidone and quaternized vinyl imidazole (i.e., polyquaternium-46);and 3-methyl-1-vinylimidazolium methosulfate-N-vinylpyrrolidone copolymer (i.e., polyquaternium-44). In addition, suitable cationic polymers include cationic polymers for personal care, such as

Supreme、

Hold、

UltraCare、

FC 370、

FC 550、

FC 552、

Excellence and combinations thereof. Any combination of the cationic polymers mentioned herein may be used.

In embodiments, the cationic polymer is a quaternary amine, and the cationic polymer is a poly (methacryloyloxyethyl trimethylammonium) halide, such as poly MADQUAT.

In embodiments, the cationic polymer is a quaternary amine and the cationic polymer is poly (vinylimidazolium).

The cationic polymer can be any suitable cationic polyvinyl alcohol or cationic cellulose. Preferably, the cationic polymer is a cationic polyvinyl alcohol. For example, the cationic polyvinyl alcohol can be Nippon Gosei GOHSEFIMER K210 ^TM Polyvinyl alcohol products.

When present, the cationic polymer (i.e., quaternary amine, cationic polyvinyl alcohol, cationic cellulose, or combinations thereof, in total) can be present in the polishing composition at any suitable concentration. Typically, the cationic polymer is present at about 1ppm to about 500ppm, for example, about 1ppm to about 475ppm, about 1ppm to about 450ppm, about 1ppm to about 425ppm, about 1ppm to about 400ppm, about 1ppm to about 375ppm, about 1ppm to about 350ppm, about 1ppm to about 325ppm, about 1ppm to about 300ppm, about 1ppm to about 275ppm, about 1ppm to about 250ppm, about 1ppm to about 225ppm, about 1ppm to about 200ppm, about 1ppm to about 175ppm, about 1ppm to about 150ppm, about 1ppm to about 125ppm, about 1ppm to about 100ppm, about 1ppm to about 75ppm, about 1ppm to about 50ppm, about 1ppm to about 40ppm, about 1ppm to about 25ppm, about 5ppm to about 225ppm, about 5ppm to about 100ppm, about 5ppm to about 50ppm, about 10ppm to about 215ppm, about 10ppm to about 100ppm, about 15ppm to about 200ppm, about 25ppm to about 25ppm, about 25ppm to about 100ppm, about 5ppm to about 175ppm, about 150ppm to about 150ppm, about 30ppm, or about 175 to about 100ppm is present in the polishing composition. Unless otherwise specified, ppm concentrations set forth herein reflect weight-based ratios of components to the total weight of the polishing composition.

When the cationic polymer is poly (vinylimidazolium), the cationic polymer is preferably present in the polishing composition at a concentration of about 1ppm to about 10ppm, e.g., about 2ppm, about 5ppm, about 6ppm, about 7ppm, about 8ppm, or about 9 ppm. More preferably, when the cationic polymer is poly (vinylimidazolium), the cationic polymer is preferably present in the polishing composition at a concentration of about 1ppm to about 5ppm, e.g., about 2ppm, about 3ppm, or about 4 ppm.

The polishing composition can optionally comprise an additive selected from the group consisting of: anionic copolymers of carboxylic, sulfonated or phosphonated monomers with acrylates, polyvinylpyrrolidone or polyvinyl alcohol (e.g., copolymers of 2-hydroxyethyl methacrylic acid with methacrylic acid); a nonionic polymer, wherein the nonionic polymer is polyvinylpyrrolidone or polyethylene glycol; silane, wherein the silane is aminosilane, ureido silane or glycidyl silane; n-oxides of functionalized pyridines (e.g., picolinic acid N-oxide); starch; cyclodextrins (e.g., alpha-cyclodextrin or beta-cyclodextrin); and combinations thereof.

When the additive is a nonionic polymer and when the nonionic polymer is polyvinylpyrrolidone, the polyvinylpyrrolidone can have any suitable molecular weight. For example, the polyvinylpyrrolidone can have a molecular weight of about 10,000g/mol to about 1,000,000g/mol, such as about 20,000g/mol, about 30,000g/mol, about 40,000g/mol, about 50,000g/mol, or about 60,000g/mol. When the additive is a nonionic polymer and when the nonionic polymer is polyethylene glycol, the polyethylene glycol can have any suitable molecular weight. For example, the molecular weight of the polyethylene glycol can be about 200g/mol to about 200,000g/mol, such as about 8000g/mol or about 100,000g/mol.

When the additive is a silane, the silane can be any suitable aminosilane, ureido silane, or glycidylsilane. For example, the silane may be 3-aminopropyltrimethoxysilane, 3-aminopropylsilanetriol, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane triol, (N, N) -dimethyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, ureidopropyltriethoxysilane or 3-glycidylpropyldimethylethoxysilane.

Preferably, when the polishing composition comprises an additive, the additive is selected from the group consisting of a copolymer of 2-hydroxyethyl methacrylic acid and methacrylic acid, polyvinylpyrrolidone, aminopropyl silanetriol, picolinic acid N-oxide, starch, alpha-cyclodextrin, beta-cyclodextrin, and combinations thereof.

The additive (i.e., an anionic copolymer of a carboxylic acid monomer, a sulfonated monomer, or a phosphonated monomer with an acrylate, polyvinylpyrrolidone, or polyvinyl alcohol; a silane; an N-oxide of a functionalized pyridine; a starch; a cyclodextrin; or a combination thereof, in total) may be present in the chemical-mechanical polishing composition in any suitable concentration. Preferably, the additive is present in the polishing composition in a concentration of about 1ppm to about 500ppm, e.g., about 5ppm to about 400ppm, about 10ppm to about 400ppm, about 15ppm to about 400ppm, about 20ppm to about 400ppm, about 25ppm to about 400ppm, about 10ppm to about 300ppm, about 10ppm to about 250ppm, about 30ppm to about 350ppm, about 30ppm to about 275ppm, about 50ppm to about 350ppm, or about 100ppm to about 300 ppm. More preferably, the additive is present in the polishing composition in a concentration of about 1ppm to about 300ppm, such as about 1ppm to about 275ppm, about 1ppm to about 250ppm, about 1ppm to about 100ppm, about 1ppm to about 50ppm, about 10ppm to about 250ppm, about 10ppm to about 100ppm, or about 35ppm to about 250 ppm.

The polishing composition optionally can further comprise a cationic polymer as described herein, in addition to one or more of the additives described herein (i.e., one or more of an anionic copolymer of a carboxylic acid monomer, sulfonated monomer, or phosphonated monomer and an acrylate, polyvinylpyrrolidone, or polyvinyl alcohol; a nonionic polymer; a silane; an N-oxide of a functionalized pyridine; a starch; and a cyclodextrin). Alternatively, the polishing composition can comprise a cationic polymer without one or more of the additives described above (i.e., without one or more of carboxylic acid monomers, sulfonated monomers, or phosphonated monomers and acrylates, polyvinylpyrrolidone, or polyvinyl alcohol; a nonionic polymer; a silane; an N-oxide of a functionalized pyridine; a starch; and a cyclodextrin).

The polishing composition comprises an aqueous carrier. The aqueous carrier comprises water (e.g., deionized water) and may contain one or more water-miscible organic solvents. Examples of the organic solvent that can be used include: alcohols such as propenyl alcohol, isopropyl alcohol, ethanol, 1-propanol, methanol, 1-hexanol, and the like; aldehydes such as acetaldehyde and the like; ketones such as acetone, diacetone alcohol, methyl ethyl ketone, and the like; esters such as ethyl formate, propyl formate, ethyl acetate, methyl lactate, butyl lactate, ethyl lactate, and the like; ethers, including sulfoxides, such as dimethyl sulfoxide (DMSO), tetrahydrofuran, bis

Alkanes, diethylene glycol dimethyl ether and the like; amides such as N, N-dimethylformamide, dimethylimidazolidinone, N-methylpyrrolidone, and the like; polyhydric alcohols and derivatives thereof such as ethylene glycol, glycerol, diethylene glycol monomethyl ether, and the like; and nitrogen-containing organic compounds, such as acetonitrile, pentylamine, iso-Propylamine, imidazole, dimethylamine and the like. Preferably, the aqueous carrier is water only, i.e., no organic solvent is present.

The pH of the polishing composition of the invention is about 3 to about 9. Typically, the polishing composition has a pH of about 3 or more. In addition, the pH of the polishing composition typically is about 9 or less. For example, the pH of the polishing composition can be about 3.5 to about 9, such as about 4 to about 9, about 4.5 to about 9, about 5 to about 9, about 5.5 to about 9, about 6 to about 9, about 6.5 to about 9, about 7 to about 9, about 7.5 to about 9, about 8 to about 9, or about 8.5 to about 9. Alternatively, the pH of the polishing composition can be about 3 to about 8.5, e.g., about 3 to about 8, about 3 to about 7.5, about 3 to about 7, about 3 to about 6.5, about 3 to about 6, about 3 to about 5.5, about 3 to about 5, about 3 to about 4.5, about 3 to about 4, or about 3 to about 3.5. Thus, the pH of the polishing composition can be defined by any two of the aforementioned endpoints.

Preferably, the pH of the polishing composition is about 3 to about 5 or about 7.0 to about 8.5. For example, in a preferred embodiment, the polishing composition comprises an abrasive, a self-stop agent of the formula Q-B as described herein, and an aqueous carrier, wherein the pH of the polishing composition is about 3 to about 5.

In another preferred embodiment, the polishing composition comprises an abrasive, a self-stopping agent of the formula Q-B as described herein, a cationic polymer, and an aqueous carrier, wherein the pH of the polishing composition is about 7.0 to about 9.0. In some preferred embodiments, the polishing composition of the invention comprises an abrasive, a self-stop agent of formula (I) as described herein, a cationic polymer, and an aqueous carrier, wherein the pH of the polishing composition is about 7.0 to about 9.0.

The polishing composition can comprise a pH adjustor and a pH buffering agent. The pH adjusting agent can be any suitable pH adjusting agent. For example, the pH adjusting agent may be an alkylamine, an alkanolamine, a quaternary amine hydroxide, ammonia, or a combination thereof. Specifically, the pH adjustor can be Triethanolamine (TEA), tetramethylammonium hydroxide (TMAH or TMA-OH), or tetraethylammonium hydroxide (TEAH or TEA-OH). In some embodiments, the pH adjusting agent is triethanolamine.

The pH adjustor can be present in the polishing composition at any suitable concentration. Desirably, the pH adjustor is present in the polishing composition in a concentration sufficient to achieve and/or maintain the pH of the polishing composition within the pH ranges set forth herein, e.g., sufficient to maintain a pH of about 3 to about 9, sufficient to maintain a pH of about 3 to about 5, or sufficient to maintain a pH of about 7.0 to about 8.5.

The polishing composition can contain any suitable buffering agent. For example, suitable buffering agents can include phosphates, sulfates, acetates, malonates, oxalates, borates, ammonium salts, oxazoles, and the like. In some embodiments, the buffering agent is 1H-benzotriazole.

The polishing composition can contain any suitable amount of the buffering agent(s), if present. For example, the buffering agent can be present in the polishing composition at a concentration of about 0.0001 wt.% or more, e.g., about 0.0005 wt.% or more, about 0.001 wt.% or more, about 0.005 wt.% or more, about 0.01 wt.% or more, or about 0.1 wt.% or more. Alternatively, or in addition, the buffering agent can be present in the polishing composition at a concentration of about 2 wt.% or less, e.g., about 1.8 wt.% or less, about 1.6 wt.% or less, about 1.4 wt.% or less, about 1.2 wt.% or less, or about 1 wt.% or less. Thus, the buffering agent can be present in the polishing composition at a concentration defined by any two of the aforementioned endpoints. For example, the buffering agent can be present in the polishing composition at a concentration of about 0.0001 wt.% to about 2 wt.%, e.g., about 0.005 wt.% to about 1.8 wt.%, about 0.01 wt.% to about 1.6 wt.%, or about 0.1 wt.% to about 1 wt.%.

The polishing composition optionally further comprises one or more other additional components. Illustrative additional components include rate enhancers, regulators, scale inhibitors, dispersants, and the like. The rate enhancing agent is desirably an organic carboxylic acid that activates the polishing particles or the substrate by forming a highly coordinating compound, such as a penta-or hexa-coordinated silicon compound. Suitable rate enhancers include, for example, picolinic acid and 4-hydroxybenzoic acid. The polishing composition can comprise a surfactant and/or a rheology control agent, including viscosity enhancing agents and coagulants (e.g., polymeric rheology control agents such as urethane polymers), dispersants, biocides (e.g., KATHON) ^TM LX) and the like. Suitable surfactants include, for example, cationic surfactantsA gemini surfactant, an anionic polyelectrolyte, a nonionic surfactant, an amphoteric surfactant, a fluorinated surfactant, mixtures thereof, and the like. By way of example, additional components may include Brij S20 (polyethylene glycol octadecyl ether) and polyethylene glycol (e.g., PEG 8000).

The polishing composition can be prepared by any suitable technique, many of which are known to those skilled in the art. The polishing composition can be prepared in a batch process or a continuous process. In general, the polishing composition can be prepared by combining the components herein in any order. The term "component" as used herein includes individual ingredients (e.g., abrasives, self-immobilizers, cationic compounds, etc.) as well as any combination of ingredients (e.g., abrasives, self-immobilizers, cationic compounds, etc.).

For example, a self-stop agent can be added to an aqueous carrier (e.g., water) at a desirable concentration. The pH can then be adjusted (as desired) and an abrasive can be added to the mixture at a desired concentration to form the polishing composition. The polishing composition can be prepared prior to use, with one or more components being added to the polishing composition immediately prior to use (e.g., within about 1 minute before use, or within about 1 hour before use, or within about 7 days before use). The polishing composition can also be prepared by mixing the components at the surface of the substrate during the polishing operation.

The polishing composition can also be provided as a concentrate which is intended to be diluted with an appropriate amount of aqueous carrier, especially water, before use. In such embodiments, the polishing composition concentrate can comprise the abrasive, the self-stop agent, the cationic polymer (if present), and the aqueous carrier in amounts such that, upon dilution of the concentrate with an appropriate amount of water, each component of the polishing composition will be present in the polishing composition in an amount within the appropriate range recited above for each component. Furthermore, as will be understood by those of ordinary skill in the art, the concentrate can contain an appropriate amount of water present in the final polishing composition to ensure that the other components are at least partially or fully dissolved in the concentrate.

Although the polishing composition can be prepared long before use, or even shortly before use, the polishing composition can also be produced by mixing the components of the polishing composition at or near the site of use. As used herein, the term "use location" refers to a location at which a polishing composition is applied to a substrate surface (e.g., a polishing pad or the substrate surface itself). When the polishing composition is to be produced using point-of-use mixing, the components of the polishing composition are separately stored in two or more storage devices.

In order to mix the components contained in the storage devices to produce the polishing composition at or near the point-of-use, the storage devices are typically equipped with one or more flow lines leading from each storage device to the point-of-use of the polishing composition (e.g., the platen, polishing pad, or substrate surface). The term "flow line" means a path from a separate storage vessel to a location of use of a component stored therein. The one or more flow lines may each lead directly to the point of use, or, in the case where more than one flow line is used, two or more of the flow lines may be combined at any location into a single flow line leading to the point of use. Further, any of the one or more flow lines (e.g., separate flow lines or combined flow lines) may first be directed to one or more other devices (e.g., pumping devices, metering devices, mixing devices, etc.) before reaching the point of use of the components.

The components of the polishing composition can be delivered to the point-of-use independently (e.g., the components are delivered to the substrate surface before mixing the components during the polishing process), or the components can be combined immediately prior to delivery to the point-of-use. A component is combined "immediately prior to delivery to the use location" if the component is combined less than 10 seconds prior to reaching the use location, preferably less than 5 seconds prior to reaching the use location, more preferably less than 1 second prior to reaching the use location, or even combined with the delivery of the component to the use location (e.g., the component is combined at the dispenser). Components are also combined "immediately prior to delivery to the use site" if the components are combined within 5m of the use site, such as within 1m of the use site or even within 10cm of the use site (e.g., within 1cm of the use site).

When two or more of the components of the polishing composition are combined prior to reaching the point-of-use, the components can be combined in the flow line and delivered to the point-of-use without the use of a mixing device. Alternatively, one or more of the flow lines may be directed into a mixing device to facilitate the combination of two or more of the components. Any suitable mixing device may be used. For example, the mixing device may be a nozzle or jet (e.g., a high pressure nozzle or jet) through which two or more of the components flow. Alternatively, the mixing device can be a container-type mixing device comprising one or more inlets by which two or more components of the polishing composition are introduced into the mixer; and at least one outlet through which the mixed components exit the mixer for delivery to a point of use, either directly or via other components of the apparatus (e.g. via one or more flow lines). Furthermore, the mixing device may comprise more than one chamber, each chamber having at least one inlet and at least one outlet, wherein two or more components are combined in each chamber. If a container-type mixing device is used, the mixing device preferably comprises a mixing mechanism to further facilitate the combination of the components. Mixing mechanisms are generally known in the art and include agitators, blenders, agitators, bladed baffles, gas distributor systems, vibrators, and the like.

The invention also provides methods of chemically-mechanically polishing a substrate using the inventive CMP compositions described herein. In an embodiment, the present invention provides a method of chemically-mechanically polishing a substrate, comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of a dielectric material and a trench region of the dielectric material, and wherein an initial step height of the patterned dielectric layer is a difference between a height of the raised region of the dielectric material and a height of the trench region of the dielectric material; (ii) providing a polishing pad; (iii) Providing a chemical-mechanical polishing composition described herein; (iv) Contacting a substrate with a polishing pad and a chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer on the surface of the substrate, thereby polishing the substrate.

More specifically, the present invention provides a method of chemically-mechanically polishing a substrate comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of a dielectric material and a trench region of the dielectric material, and wherein an initial step height of the patterned dielectric layer is a difference between a height of the raised region of the dielectric material and a height of the trench region of the dielectric material; (ii) providing a polishing pad; (iii) Providing a chemical-mechanical polishing composition comprising (a) an abrasive; (b) A self-immobilizer of formula Q-B, wherein Q is a substituted or unsubstituted hydrophobic group, or a steric-conferring group, B is a binding group, wherein the binding group has the structure C (O) -X-OH or-C (O) -OH, wherein X is C1-C2 alkyl; (c) an aqueous carrier; (d) Optionally a cationic polymer, wherein the pH of the polishing composition is about 3 to about 9; (iv) Contacting a substrate with a polishing pad and the chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer on the surface of the substrate, thereby polishing the substrate.

The invention also provides a method of chemically-mechanically polishing a substrate comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of a dielectric material and a trench region of the dielectric material, and wherein an initial step height of the patterned dielectric layer is a difference between a height of the raised region of the dielectric material and a height of the trench region of the dielectric material; (ii) providing a polishing pad; (iii) Providing a chemical-mechanical polishing composition comprising (a) an abrasive comprising cerium oxide; (b) a self-stopping agent selected from the group consisting of: kojic acid, maltol, caffeic acid, crotonic acid, tiglic acid, 2-pentenoic acid, 2-hydroxynicotinic acid, ethyl maltol, potassium sorbate, sorbic acid, deferiprone, valeric acid, and combinations thereof; and (c) an aqueous carrier, wherein the polishing composition has a pH of about 3 to about 9; (iv) Contacting a substrate with a polishing pad and a chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer on the surface of the substrate, thereby polishing the substrate.

The invention also provides a method of chemically-mechanically polishing a substrate comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of a dielectric material and a trench region of the dielectric material, and wherein an initial step height of the patterned dielectric layer is a difference between a height of the raised region of the dielectric material and a height of the trench region of the dielectric material; (ii) providing a polishing pad; (iii) Providing a chemical-mechanical polishing composition comprising (a) an abrasive; (b) Self-immobilizers selected from compounds of formula (I)

Wherein R is selected from: hydrogen, alkyl, cycloalkyl, aryl, heterocycloalkyl, and heterocycloaryl, each of which may be substituted or unsubstituted; (c) an aqueous carrier; (d) A cationic polymer, wherein the polishing composition has a pH of about 7 to about 9; (iv) Contacting a substrate with a polishing pad and a chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer on the surface of the substrate, thereby polishing the substrate.

The invention also provides a method of chemically-mechanically polishing a substrate comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of a dielectric material and a trench region of the dielectric material, and wherein an initial step height of the patterned dielectric layer is a difference between a height of the raised region of the dielectric material and a height of the trench region of the dielectric material; (ii) providing a polishing pad; (iii) Providing a chemical-mechanical polishing composition comprising (a) an abrasive; (b) A self-immobilizer selected from compounds of formula (II), (III) or (IV),

Z-(C(X ¹ X ² ) _n ) _p -CO ₂ M(III)，

Wherein Z is selected from N, C ₁ -C ₆ Alkyl radical, C ₁ -C ₆ Alkenyl radical, C ₁ -C ₆ Alkynyl and aryl groups (e.g., phenyl, benzyl, naphthyl, azulene, anthracene, pyrene, etc.), X ¹ And X ² Independently selected from hydrogen, hydroxy, amino and C ₁ -C ₆ Alkyl radical, C ₁ -C ₆ Alkenyl, and wherein X taken together with the carbon to which it is attached ¹ And X ² Can form sp ² Hybrid carbon, n is 1 or 2, p is 0 to 4, and M is selected from hydrogen and a suitable counter ion (e.g., a group I metal), each of which may be substituted or unsubstituted,

wherein X, Y and Z are independently selected from H, O, S, NH and CH ₂ ，R ¹ 、R ² And R ³ Independently selected from H, alkyl, alkenyl, alkynyl, aryl, halo, and haloalkyl, and M is selected from hydrogen and a suitable counterion; (c) An aqueous carrier, wherein the polishing composition has a pH of about 3 to about 9; (iv) Contacting a substrate with a polishing pad and a chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer on the surface of the substrate, thereby polishing the substrate.

The invention also provides a method of chemically-mechanically polishing a substrate comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of a dielectric material and a trench region of the dielectric material, and wherein an initial step height of the patterned dielectric layer is a difference between a height of the raised region of the dielectric material and a height of the trench region of the dielectric material; (ii) providing a polishing pad; (iii) Providing a chemical-mechanical polishing composition comprising (a) an abrasive comprising cerium oxide; (b) A self-stop agent selected from hydroxamic acids (such as acetyl hydroxamic acid, phenyl hydroxamic acid, salicyl hydroxamic acid, and combinations thereof); (c) a cationic polymer; and (d) an aqueous carrier, wherein the polishing composition has a pH of about 7 to about 9; (iv) Contacting a substrate with a polishing pad and a chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer on the surface of the substrate, thereby polishing the substrate.

The polishing composition of the invention is suitable for polishing any suitable substrate. The polishing composition is particularly useful for polishing a substrate comprising a silicon oxide layer. Suitable substrates include, but are not limited to, flat panel displays, integrated circuits, memory or rigid disks, metals, semiconductors, interlayer dielectric (ILD) devices, micro-electromechanical systems (MEMS), 3D NAND devices, ferroelectrics, and magnetic heads. The polishing composition is particularly well suited for planarizing or polishing a substrate that has undergone Shallow Trench Isolation (STI) processing. Desirably, the substrate includes a dielectric-containing (e.g., silicon oxide-containing) surface, particularly a surface having patterned dielectric material regions comprising raised dielectric regions separated by trench regions of dielectric material. The substrate may further comprise at least one other layer, such as an insulating layer. The insulating layer can be a metal oxide, porous metal oxide, glass, organic polymer, fluorinated organic polymer, or any other suitable high or low- κ insulating layer. The insulating layer can comprise, consist essentially of, or consist of silicon oxide, silicon nitride, or a combination thereof. The silicon oxide layer can comprise, consist essentially of, or consist of any suitable silicon oxide, many of which are known in the art. For example, the silicon oxide layer may comprise Tetraethoxysilane (TEOS), high Density Plasma (HDP) oxide, borophosphosilicate glass (BPSG), high Aspect Ratio Process (HARP) oxide, spin-on dielectric (SOD) oxide, chemical Vapor Deposition (CVD) oxide, plasma Enhanced Tetraethylorthosilicate (PETEOS), thermal oxide, or undoped silicate glass. The substrate may further comprise a metal layer. The metal may comprise, consist essentially of, or consist of any suitable metal, many of which are known in the art, such as copper, tantalum, tungsten, titanium, platinum, ruthenium, iridium, aluminum, nickel, or combinations thereof.

In accordance with the present invention, a substrate can be planarized or polished with the polishing composition described herein by any suitable technique. The polishing method of the invention is particularly suited for use in conjunction with chemical-mechanical polishing (CMP) equipment. Typically, the CMP apparatus comprises: a platform which, in use, is in motion and has a velocity resulting from orbital, linear or circular motion; a polishing pad in contact with the platen and moving with the platen while in motion; and a carrier that holds a substrate to be polished by contacting and moving relative to a surface of the polishing pad. The polishing of the substrate is carried out by placing the substrate in contact with the polishing composition of the invention and typically a polishing pad and then abrading at least a portion of the surface of the substrate (e.g., silicon oxide or one or more of the substrate materials described herein) with the polishing composition and typically a polishing pad to polish the substrate. According to the present invention, any suitable polishing conditions can be used to polish the substrate.

The chemical-mechanical polishing composition can be used in conjunction with any suitable polishing pad (e.g., polishing surface) to planarize or polish a substrate. Suitable polishing pads include, for example, woven and non-woven polishing pads. Further, suitable polishing pads can comprise any suitable polymer of varying density, hardness, thickness, compressibility, ability to rebound upon compression, and compression modulus. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, coformed products thereof, and mixtures thereof.

Although the present compositions and methods exhibit self-stop behavior, the CMP apparatus can further comprise an in situ polishing endpoint detection system, many of which are known in the art. Techniques for inspecting and monitoring the polishing process by analyzing light or other radiation reflected from the surface of the workpiece are known in the art. Such methods are described, for example, in U.S. Pat. No. 5,196,353, U.S. Pat. No. 5,433,651, U.S. Pat. No. 5,609,511, U.S. Pat. No. 5,643,046, U.S. Pat. No. 5,658,183, U.S. Pat. No. 5,730,642, U.S. Pat. No. 5,838,447, U.S. Pat. No. 5,872,633, U.S. Pat. No. 5,893,796, U.S. Pat. No. 5,949,927, and U.S. Pat. No. 5,964,643. Desirably, inspection or monitoring of the progress of the polishing process with respect to the workpiece being polished enables the determination of the polishing endpoint, i.e., the determination of when to terminate the polishing process with respect to a particular workpiece.

For substrates of any type of device, the substrate surface may comprise a continuous and structured (non-planar, non-smooth) layer of dielectric material placed over an underlying layer that also comprises surface structures or topography. This structured, non-planar region of the surface of the dielectric material is referred to as the "patterned dielectric". Which is created by a dielectric material placed over an underlying non-uniform structure to fill trenches or holes present in the underlying layer. To ensure complete filling of all trenches or holes etc. and sufficient coverage over the surface of the underlying layer containing the trenches or holes etc., a dielectric material is deposited in excess amounts. The dielectric material will conform to the uneven topography of the underlying layer, resulting in a deposited continuous dielectric surface characterized by raised regions separated by trenches. The raised areas will be the locations of active polishing and material removal, meaning the locations from which most of the dielectric material is removed. The patterned dielectric material is also characterized by a so-called "step height," which is the height of the dielectric material relative to the raised regions of the height of the dielectric material adjacent the trenches.

The polishing composition of the invention is particularly well suited for planarizing or polishing a substrate that has undergone Shallow Trench Isolation (STI) or similar processing, thereby causing dielectric to be coated over a structured underlying layer to create regions of patterned dielectric material. Typical step heights may range from about 1,000 angstroms to about 7,000 angstroms for substrates that have been subjected to shallow trench isolation.

Certain embodiments of the described polishing compositions are also suitable for planarizing or polishing a substrate as a 3D NAND flash memory device in process. In such substrates, the underlying layer is made of a semiconductor layer comprising trenches, holes or other structures having a high aspect ratio (such as aspect ratio of at least 10. When the surface of structures having such high aspect ratios is covered by a dielectric material, the resulting patterned dielectric will exhibit a high step height, such as a step height substantially greater than about 7,000 angstroms, e.g., greater than about 10,000 angstroms, greater than about 20,000 angstroms, greater than about 30,000 angstroms, or greater than about 40,000 angstroms or more.

The dielectric material of any of the devices described herein may comprise, consist essentially of, or consist of any suitable dielectric material, many of which are well known, including various forms of silicon oxide and silicon oxide-based dielectric materials. For example, a dielectric material comprising silicon oxide or a silicon oxide-based dielectric layer may comprise, consist of, or consist essentially of any one or more of the following: tetraethoxysilane (TEOS), high Density Plasma (HDP) oxide, phosphosilicate glass (PSG), borophosphosilicate glass (BPSG), high Aspect Ratio Process (HARP) oxide, spin-on dielectric (SOD) oxide, chemical Vapor Deposition (CVD) oxide, plasma Enhanced Tetraethylorthosilicate (PETEOS), thermal oxide, or undoped silicate glass. In the past, some examples of substrates that require planarization of a patterned dielectric have been prepared to include a silicon nitride layer (e.g., a "silicon nitride cap" or "liner") at a location below an active polishing region of a patterned dielectric material, e.g., a "cap" located above a mesa (land) surface of a structured semiconductor layer. The silicon nitride is designed to stop the polishing and removal of dielectric material at the active area when the silicon nitride layer is reached. The silicon nitride layer is used to pause (halt) the removal of material during the polishing step in a manner intended to reduce trench loss and dishing in the final topography. However, this step adds significant cost to the manufacturing process and may still not completely prevent dishing.

According to the method of the present invention, the substrate may include a silicon nitride liner at the intended end of the dielectric polishing and removal step. In other embodiments, the substrate does not require and optionally and preferably does not include a silicon nitride "liner" or "cap" disposed at the end of the step of removing dielectric from the active region.

Desirably, the patterned dielectric material is planarized and polished to reduce an initial step height between the raised region (having an initial height) and the trench (having an initial trench thickness). In order to efficiently and effectively achieve this planarization, the inventive method has a high removal rate of the raised areas of the (active) patterned dielectric material and a substantially lower removal rate of the dielectric material of the trenches. Most preferably, the method of the invention also exhibits self-stop behavior.

During CMP polishing or planarization, dielectric material is removed from the raised regions and from the trenches in small amounts. During polishing, the height of the raised region is reduced to eventually be substantially level with the height of the trench. For example, this may mean reducing the step height to less than 1,000 angstroms, such as less than 900 angstroms, less than 500 angstroms, less than 300 angstroms, or less than 250 angstroms. The reduction in height of the raised areas removes the pattern of the raised areas between the trenches, effectively removing and converting the pattern to areas of planarized dielectric, i.e., "blanket dielectric" or "blanket oxide," meaning substantially planarized areas of dielectric material.

Depending on the substrate being polished, the initial step height, as measured prior to beginning the CMP processing step, can be at least 1,000 angstroms, such as at least 2,000 angstroms or at least 5,000 angstroms, and can be substantially greater, such as greater than 7,000 angstroms, such as at least 10,000 angstroms, at least 20,000 angstroms, at least 30,000 angstroms, or at least 40,000 angstroms. After polishing, the step height is reduced and the trench thickness is reduced.

FIG. 1 depicts having an initial step height (h) ₀ ) And initial trench thickness (t) ₀ ) An exemplary substrate of (1). The step height material may be primarily dielectric, such as TEOS, BPSG, or other amorphous silicon oxide (silicon oxide) -containing material. A key step in 3D NAND dielectric (and other bulk (bulk) oxide removal) processing is to reduce the step height (h) ₁ ) (e.g., to less than about

Or to less than about

) And has a minimum trench loss (t) ₀ -t ₁ ). For good planarization efficiency, the final step height must be reached without significant trench loss. This requires that the polishing composition have a higher removal rate in the active (i.e., raised) regions than in the trench regions. In addition, preferred polishing compositions will produce a "self-stop" or "stop on plane" behavior to allow for more efficient final polishing without causing overpolishing. Desirably, the inventive polishing composition has a much higher pattern removal rate (removal rate at active areas) than on a blanket (substantially smooth) dielectric material.

The removal rate of the dielectric material at the active area is referred to as the removal rate of the patterned material (e.g., patterned oxide) or "pattern removal rate" or "active removal rate". The rate of pattern removal achieved using the methods and polishing compositions as described herein can be any suitable rate, and for any given process and substrate will depend in large part on the dimensions (e.g., pitch and width) of the raised regions. According to preferred methods, the removal rate of the patterned dielectric material can be at least about 2,000 angstroms/minute, preferably at least about 4,000 angstroms/minute, such as at least about 5,000 angstroms/minute, at least about 6,000 angstroms/minute, at least about 10,000 angstroms/minute, at least about 14,000 angstroms/minute, or at least about 15,000 angstroms/minute.

According to a preferred method, the patterned dielectric may be processed to planarize the surface by CMP processing the patterned dielectric for a time less than 5 minutes, such as less than 3 minutes, less than 2 minutes, or less than 1 minute. This may be achieved for a substrate having a patterned dielectric material comprising a step height of at least 7,000 angstroms, such as at least 10,000 angstroms, at least 20,000 angstroms, at least 30,000 angstroms, or at least 40,000 angstroms. The surface is considered to be effectively planarized when a reduced step height (i.e., "residual" step height) of less than 1,000 angstroms (by polishing) is achieved. Thus, the inventive polishing compositions and methods can provide a remaining step height of less than 1,000 angstroms, such as less than 900 angstroms, less than 500 angstroms, less than 300 angstroms, or less than 250 angstroms.

Furthermore, according to the preferred polishing methods using the polishing compositions as described herein, trench loss can be reduced and planarization efficiency can be improved relative to polishing compositions that do not contain a self-stop agent (e.g., a compound of formula Q-B) as described herein. The trench loss refers to the thickness (t) of the trench before the CMP process ₀ ) And trench thickness (t) after CMP processing ₁ ) The difference between, i.e. the trench loss is equal to t ₀ -t ₁ (for a given processing time or result) (fig. 1). Preferably, the amount of trench loss that will occur during polishing to planarization (e.g., as defined by a "remaining" step height of less than 1,000 angstroms, such as less than 900 angstroms, less than 500 angstroms, less than 300 angstroms, or less than 250 angstroms) or for a given amount of processing time can be reduced by having a self-stop agent as described herein present in the polishing composition as described herein. Thus, the polishing methods described herein produce substantially lower (e.g., at least 10% less) groove loss than a similar polishing composition (e.g., a polishing combination free of a compound of formula Q-B) without a self-stop agent as described herein using the same processing conditions and equipmentObject) trench loss resulting from polishing the same type of substrate. Desirably, the method of polishing a substrate of the invention provides a trench loss of less than about 2,000 angstroms (e.g., less than about 1,500 angstroms, less than about 1,000 angstroms, less than about 500 angstroms, or less than about 250 angstroms).

Lower trench loss can be reflected in planarization efficiency, which means a reduction in step height

Divided by trench loss

According to preferred methods of the invention, planarization efficiency can be improved by having a self-stop agent as described herein present in a polishing composition as described herein. Thus, the polishing methods described herein result in planarization efficiencies that are substantially higher (e.g., at least 10% higher) than the planarization efficiencies that result from polishing the same type of substrate with a similar polishing composition (e.g., a polishing composition that does not contain a compound of formula Q-B) but without a self-stop agent as described herein using the same processing conditions and equipment. Desirably, the method of polishing a substrate of the present invention provides a planarization efficiency of at least about 2.0, preferably at least about 3.0, such as at least about 3.5.

Preferred methods may also exhibit self-stop behavior, meaning that the removal rate of dielectric material from the blanket dielectric material (i.e., "blanket removal rate") is significantly lower than the removal rate of patterned dielectric material when step heights of less than 1,000 angstroms, less than 900 angstroms, less than 500 angstroms, less than 300 angstroms, or less than 200 angstroms are reached. It is believed that self-stop behavior occurs if the removal rate of the blanket dielectric material is less than about 1,000 angstroms/minute. Thus, in preferred embodiments, the inventive method provides a blanket dielectric material removal rate of less than about 1,000 angstroms/minute, such as less than about 800 angstroms/minute, less than about 500 angstroms/minute, less than about 300 angstroms/minute, or less than about 200 angstroms/minute.

By other measurements, self-stop behavior may be measured by comparing the removal rate of the blanket dielectric material to the removal rate of the patterned dielectric material. A low ratio of the blanket removal rate to the pattern removal rate indicates good self-stopping behavior. Thus, in preferred embodiments, the ratio of the removal rate of the blanket dielectric material to the removal rate of the patterned dielectric material is less than about 1, such as less than about 0.5, less than about 0.3, or less than about 0.1. Thus, the inventive polishing method results in a ratio of blanket removal rate to pattern removal rate that is substantially lower (e.g., at least about 10% less) than the ratio of blanket removal rate to pattern removal rate that results from polishing the same type of substrate with a similar polishing composition (e.g., a polishing composition that does not contain a compound of formula Q-B) but does not contain a self-stop agent as described herein using the same processing conditions and equipment.

In an embodiment, the present invention provides a method wherein the patterned dielectric layer comprises an initial step height of at least about 1,000 angstroms, wherein the method comprises reducing the initial step height to less than about 900 angstroms during polishing to produce a planarized dielectric, and wherein the removal rate of the planarized dielectric is less than about 1,000 angstroms per minute.

In an embodiment, the present invention provides a method comprising removing at least about 10,000 angstroms of raised regions of dielectric material from a surface of a patterned dielectric layer.

In embodiments, the present invention provides methods wherein the ratio of the removal rate of the raised regions of dielectric material to the removal rate of the trench regions of dielectric material is greater than about 5, preferably greater than about 10, greater than about 15, or greater than about 20.

In an embodiment, the present invention provides a method wherein the removal rate of the raised regions of dielectric material is greater than about 1000 angstroms per minute. Thus, in preferred embodiments, the removal rate of the raised regions of dielectric material is greater than about 2,000 angstroms/minute, such as greater than about 4,000 angstroms/minute, greater than about 5,000 angstroms/minute, greater than about 6,000 angstroms/minute, greater than about 10,000 angstroms/minute, or greater than about 15,000 angstroms/minute.

In an embodiment, the present invention provides a method wherein the pattern dielectric layer comprises a dielectric material selected from the group consisting of silicon oxide, tetraethoxysilane, phosphosilicate glass, borophosphosilicate glass, and combinations thereof.

Description of the preferred embodiment

(1) In embodiment (1), a chemical-mechanical polishing composition is provided comprising: (a) an abrasive; (b) A self-stopping agent of formula Q-B, wherein Q is a substituted or unsubstituted hydrophobic group, or a steric-conferring group, and B is a binding group, wherein the binding group has the structure: -C (O) -X-OH or-C (O) -OH, wherein X is C1-C2 alkyl (e.g. any of the compounds of formulae (II), (III) and (IV)); and (c) an aqueous carrier, wherein the polishing composition has a pH of about 3 to about 9.

(2) In embodiment (2) there is provided the polishing composition of embodiment (1), wherein the abrasive is selected from the group consisting of ceria, zirconia, and combinations thereof.

(3) Provided in embodiment (3) is the polishing composition of embodiment (2), wherein the abrasive is cerium oxide.

(4) Provided in embodiment (4) is the polishing composition of any one of embodiments (1) through (3), wherein the abrasive is present in the polishing composition in a concentration of about 0.001 wt.% to about 5 wt.%.

(5) Provided in embodiment (5) is the polishing composition of any one of embodiments (1) through (4), wherein Q is selected from the group consisting of alkyl, cycloalkyl, aromatic, heterocyclic, heteroaromatic, and combinations thereof.

(6) Provided in embodiment (6) is the polishing composition of embodiment (5), wherein Q is substituted with one or more groups selected from hydroxyl, alkyl, halogen, amine, or any combination thereof.

(7) In embodiment (7) there is provided the polishing composition of embodiment (1), wherein Q-B is selected from the group consisting of maltol, kojic acid, crotonic acid, tiglic acid, 2-pentenoic acid, valeric acid, benzoic acid, 3, 4-dihydroxybenzoic acid, 3, 5-dihydroxybenzoic acid, caffeic acid, ethyl maltol, potassium sorbate, sorbic acid, and combinations thereof.

(8) Provided in embodiment (8) is the polishing composition of any one of embodiments (1) through (7), wherein the self-stopping agent is present in the polishing composition at a concentration of about 0.5 wt.% or less.

(9) Provided in embodiment (9) is the polishing composition of any one of embodiments (1) through (8), further comprising a cationic polymer.

(10) In embodiment (10) there is provided the polishing composition of embodiment (9), wherein the cationic polymer comprises a monomer selected from the group consisting of quaternary amines, cationic polyvinyl alcohols, cationic celluloses, and combinations thereof.

(11) In embodiment (11) there is provided the polishing composition of embodiment (10), wherein the cationic polymer comprises a quaternary amine monomer, and wherein the quaternary amine monomer is selected from the group consisting of vinylimidazolium, methacryloyloxyethyltrimethylammonium halide, diallyldimethylammonium halide, and combinations thereof.

(12) Provided in embodiment (12) is the polishing composition of embodiment (9), wherein the cationic polymer is selected from the group consisting of poly (vinylimidazolium), poly (methacryloyloxyethyltrimethylammonium) chloride, poly (diallyldimethylammonium) chloride, polyquaternium-2, and combinations thereof.

(13) Provided in embodiment (13) is the polishing composition of any one of embodiments (1) to (12), wherein the pH of the polishing composition is about 6.5 to about 8.5.

(14) Provided in embodiment (14) is the polishing composition of any one of embodiments (1) to (12), wherein the pH of the polishing composition is about 3 to about 5.

(15) Provided in embodiment (15) is the polishing composition of any one of embodiments (1) to (14), further comprising a rate enhancing agent and/or a pH buffering agent.

(16) In embodiment (16), there is provided a chemical-mechanical polishing composition comprising: (a) an abrasive comprising cerium oxide; (b) a self-stopping agent selected from the group consisting of: kojic acid, crotonic acid, tiglic acid, valeric acid, 2-pentenoic acid, maltol, benzoic acid, 3, 4-dihydroxybenzoic acid, 3, 5-dihydroxybenzoic acid, caffeic acid, ethyl maltol, potassium sorbate, sorbic acid, and combinations thereof; and (c) an aqueous carrier, wherein the polishing composition has a pH of about 3 to about 9.

(17) Provided in embodiment (17) is the polishing composition of embodiment (16), wherein the pH of the polishing composition is about 3 to about 5.

(18) Provided in embodiment (18) is the polishing composition of embodiment (16), further comprising a planarizing agent comprising a cationic polymer selected from the group consisting of poly (vinylimidazolium), poly (methacryloyloxyethyl trimethylammonium) chloride, poly (diallyldimethylammonium) chloride, polyquaternium-2, and combinations thereof.

(19) Provided in embodiment (19) is the polishing composition of embodiment (18), wherein the pH of the polishing composition is about 6.5 to about 8.5.

(20) In embodiment (20), a chemical-mechanical polishing composition is provided comprising:

(a) An abrasive comprising cerium oxide;

(b) A self-immobilizer selected from compounds of formula (I):

(c) A cationic compound selected from: aluminum salts, 2- (dimethylamino) ethyl methacrylate, diallyldimethylammonium, poly (vinylimidazolium), poly (methacryloyloxyethyltrimethylammonium) halide, poly (diallyldimethylammonium) halide, polyquaternium-2, polyquaternium-11, polyquaternium-16, polyquaternium-46, polyquaternium-44, luviquat Supreme, luviquat Hold, luviquat UltraCare, luviquat FC370, luviquat FC 550, luviquat FC 552, luviquat Excellence, and combinations thereof; and

(d) An aqueous carrier, a water-based vehicle,

wherein the polishing composition has a pH of about 7 to about 9.

(21) Provided in embodiment (21) is the polishing composition of embodiment (20), wherein the pH of the polishing composition is about 7 to about 9.

(22) In an embodiment (22), there is provided a method of chemically-mechanically polishing a substrate, comprising: (i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate, wherein the patterned dielectric layer comprises a raised region of a dielectric material and a trench region of the dielectric material, and wherein an initial step height of the patterned dielectric layer is a difference between a height of the raised region of the dielectric material and a height of the trench region of the dielectric material; (ii) providing a polishing pad; (iii) Providing a chemical mechanical polishing composition as in any one of embodiments (1) to (21); (iv) Contacting a substrate with a polishing pad and a chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer on the surface of the substrate, thereby polishing the substrate.

(23) In embodiment (23) there is provided the polishing method of embodiment (22), wherein the patterned dielectric layer comprises an initial step height of at least about 1,000 angstroms, wherein the method comprises reducing the initial step height to less than about 900 angstroms during polishing to produce a planarized dielectric, and wherein the removal rate of the planarized dielectric is less than about 1,000 angstroms per minute.

(24) In embodiment (24) there is provided the polishing method of embodiment (22) or embodiment (23), wherein the method comprises removing at least about 10,000 angstroms of the raised region of dielectric material from the surface of the patterned dielectric layer.

(25) In embodiment (25) there is provided the polishing method of any one of embodiments (22) to (24), wherein a ratio of a removal rate of the raised regions of dielectric material to a removal rate of the trench regions of dielectric material is greater than about 5.

(26) In embodiment (26) there is provided the polishing method of any one of embodiments (22) to (25), wherein the removal rate of the raised regions of dielectric material is greater than about 1,000 angstroms/minute.

(27) In embodiment (27) there is provided the polishing method of any one of embodiments (22) to (26), wherein the patterned dielectric layer comprises a dielectric material selected from the group consisting of silicon oxide, tetraethoxysilane, phosphosilicate glass, borophosphosilicate glass, and combinations thereof.

Examples

The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope.

The following abbreviations are used in the examples: PEG8000 refers to polyethylene glycol having a molecular weight of 8,000g/mol; pMADQUAT refers to poly-MADQUAT; SHA refers to salicyl hydroxamic acid; BHA refers to phenylhydroxamic acid; BTA means 1H-benzotriazole; TEA refers to triethanolamine; POU refers to the location of use; RR refers to removal rate; AA refers to the active region; TA refers to the trench region; BW refers to TEOS blanket wafer; and SH refers to the step height.

Example 1

This example illustrates the effect of a self-stopping agent, optionally in combination with a cationic compound, on the polishing performance in a polishing composition comprising the same.

The patterned substrate was polished with fourteen polishing compositions (i.e., polishing compositions 1A-1N). Polishing compositions 1A-1N were prepared by mixing abrasive compositions C1 and C2 (described in table 1 below) with additive formulations F1-F15 (described in table 2 below) in a ratio of 7 by volume.

Abrasive compositions C1 and C2 contained a ceria abrasive, picolinic acid, and water, as illustrated in table 1. HC60 and HC30 cerium oxide abrasives are available from Rhodia. The H-30 ceria abrasive is wet-process ceria as described in the prior application (U.S. published patent application 2016/0257855). Each of the abrasive compositions C1 and C2 had a pH of 4.2.

Table 1: abrasive composition

Additive formulations F4-F15 contained cationic compounds (pMADQUAT), a self-stop agent (SHA or BHA) and an additive (BTA), as illustrated in table 2. The pH of each of the additive formulations F3-F15 was adjusted using Triethanolamine (TEA). Additive formulations F1 and F2 were alkali-free and had a pH of 4.2.

Table 2: additive formulations

Will comprise an initial coatingThe cover is approximately at the step height

Has a pattern density of 50% (about 250 μm TEOS features) on a patterned silicon substrate

Thick features) on a single patterned sample (coupon) substrate (with 40mm square cuts on each side of a SKW 7-2 wafer from SKW Associates, inc.) on a POLI-300 (G) with a 200mm CMP platen (G)&Inc.) on IC1010 ^TM The pad (Rohm and Haas Electronic Materials) was polished for 60 seconds at 20.68kPa (3 psi) downforce with a platen speed and head speed of 120rpm and 110rpm, respectively. The total flow rate of the polishing composition was 200mL/min. The results are set forth in table 3.

Table 3: effect of cationic Compounds and pH on polishing Performance

As is apparent from the results set forth in table 3, polishing compositions 1A and 1B having an acidic pH (pH 4.2) comprising an abrasive formulation with a self-stopping agent (hydroxamic acid) desirably exhibited a ratio of active region removal to trench region removal in the range of about 3 to 6. Thus, polishing compositions 1A and 1B are desirably "self-stopping" compositions that planarize patterned material while retaining trench material.

Polishing composition 1I, which included both a self-stop agent and a cationic compound, exhibited a ratio of active region removal to trench region removal of about 8.6 and a pH of 6.1

Active area is removed. Thus, polishing composition 1I is also a "self-stopping" composition that planarizes patterned material while retaining trench material.

Polishing compositions 1C-1H and 1J-1N comprising both a self-stop agent and a cationic compound exhibit a ratio of active region removal to trench region removal in the range of about 5.76

To about

Active area is removed. Thus, polishing compositions 1C-1H and 1J-1N are "self-stopping" compositions that planarize patterned material while retaining trench material.

Example 2

The patterned substrate was polished with three polishing compositions (i.e., polishing compositions 2A-2C). Polishing compositions 2B and 2C were prepared using the abrasive composition and additive formulation described in example 1 (7 by volume). Composition 2A (comparative) contained only abrasive formulation C2.

The inclusion of an initial coating of about height steps of various widths and densities obtained from Silyb Inc

TEOS (about) on a patterned silicon substrate

Thick feature) on an AP-300 with a 300mm CMP platen ^TM IC1010 used on (CTS co., ltd.) ^TM The pad was polished multiple times at 3psi down force, with platen and head speeds of 93rpm and 87rpm, respectively. The total flow rate of the polishing composition was 250mL/min.

Table 4: description of polishing compositions 2A-2C

Polishing composition	Abrasive and additive composition (7	pH(POU)	Polishing time (seconds)
				2A (comparison)	C2	4.2	35
2B (invention)	C2:F2	4.2	35 and 45
				2C (invention)	C2:F12	7.7	30. 60 and 90

The remaining active thickness before and after polishing, depending on the pitch and pattern density as a result of example 2, is graphically represented in fig. 2.

As is apparent from the results presented in fig. 2, polishing composition 2C of the invention, which contained abrasive, phenylhydroxamic acid, and poly MADQUAT at a PH (POU) of 7.7, exhibited a low pattern density dependence as polishing time increased, and had a uniform topography over the substrate when stopped (polishing composition 2C polished for 90 seconds) as compared to polishing compositions 2A and 2B.

Additional polishing performance data is set forth in table 5 and figure 2. The data in table 5 depicts the remaining active thickness over the wafer as a function of polishing time, which includes 900 μm TEOS features (50% pattern density).

Table 5: residual silicon oxide as a function of polishing time

As is apparent from the results illustrated in table 5 and figure 2, polishing composition 2C initially exhibited a lower polishing rate on the patterned material, but the rate over the wafer decreased uniformly with decreasing step height as compared to the comparative (polishing compositions 2A and 2B). This example further illustrates the advantage of a self-immobilizer polishing composition formulated with a self-immobilizer (e.g., hydroxamic acid) and a cationic compound (e.g., pMADQUAT) at the point-of-use versus a control polishing composition for topographical variations (pattern density dependency) across a substrate and within-wafer polishing rate variations (WIWNU) at a pH in the range of about 7.0 to about 8.5.

Example 3

This example illustrates the effect of the pH range and self-stop agent of the present invention, optionally in combination with a cationic compound, on polishing performance.

Patterned substrates and TEOS-coated silicon substrates were polished with fourteen polishing compositions (i.e., polishing compositions 3A-3N) as described in Table 7 below. The polishing composition was prepared by mixing the abrasive composition (described in table 1) and the additive formulation described in table 6 in a ratio of 7.

Additive formulations G1-G5 contained no cationic compounds, while formulations G6-G14 contained cationic compounds (i.e., pMADQUAT or Luviquat Supreme). All formulations contained a self-stopper as illustrated in table 6 and additional components.

Table 6: additive formulations

The patterned wafer was obtained from Silyb Inc. and included an initial coverage at a step height of about

Has a pattern density of 50% of 900 μm TEOS features (about

Thick features). TEOS blanket wafers were obtained from WRS materials. Using MIRRA ^TM The polishing tool (Applied Materials, inc.) polished the test wafers for 60 seconds and 90 seconds for the patterned wafer and the blanket wafer, respectively. Used with a 3psi downforce and a platen speed and head speed of 93rpm and 87rpm, respectively, on a 200mm platen

E6088 (Cabot Microelectronics Corporation) polishing pads. The total slurry flow rate was 150mL/min. The results are set forth in table 7.

Table 7: effect of additives and POU pH on polishing Performance

As is apparent from the results illustrated in table 7, all polishing compositions comprising the abrasive formulation and the self-stop agent exhibited high step height removal rates for the pattern and low oxide removal rates on the blanket wafer. This indicates that as the patterned wafer is planarized, a significant removal rate drop occurs on the patterned wafer. The ratio of the step height removal rate to the oxide blanket removal rate is in the range of about 4 to 24 depending on the type of self-stop agent and POU pH and cationic compound.

All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

The use of the terms "a" and "an" and "the" and "at least one" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term "at least one of + a list of one or more items (e.g.," at least one of a and B ") should be construed to mean one item (a or B) selected from the listed items or any combination of two or more of the listed items (a and B), unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all embodiments, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. A chemical-mechanical polishing composition comprising:

(a) An abrasive selected from the group consisting of ceria, zirconia, and combinations thereof,

(b) A self-stopping agent selected from:

a compound of formula (II)

In the formula (II), X ¹ To X ³ Each independently selected from N, O, S, sp ² Hybrid carbon and CY ¹ Y ² Wherein Y is ¹ And Y ² Each independently selected from hydrogen, hydroxy, C ₁ -C ₆ Alkyl, halogen and combinations thereof, and Z ¹ -Z ³ Each independently selected from hydrogen, hydroxy, C ₁ -C ₆ Alkyl and combinations thereof, each of which is substituted or unsubstituted;

a compound of formula (III):

Z-(C(X ¹ X ² ) _n ) _p -CO ₂ M(III)，

in formula (III), Z is selected from N, C ₁ -C ₆ Alkenyl radical, C ₁ -C ₆ Alkynyl and aryl, X ¹ And X ² Independently selected from hydrogen, hydroxy, amino and C ₁ -C ₆ Alkyl radical, C ₁ -C ₆ Alkenyl, n is 1 or 2, p is 0 to 4, and M is selected from a group I metal, each of which is substituted or unsubstituted; and combinations thereof;

tiglic acid, crotonic acid, 2-hydroxynicotinic acid, 2-pentenoic acid, 3-pentenoic acid, salts thereof, and combinations thereof;

(c) A cationic compound, wherein the cationic compound is a polymer comprising monomers selected from the group consisting of quaternary amines, cationic polyvinyl alcohols, cationic celluloses, and combinations thereof, and

(d) An aqueous carrier, a water-based vehicle,

wherein the polishing composition has a pH of 3 to 9.

2. The polishing composition of claim 1, wherein the cationic compound is an oligomer comprising a monomer selected from the group consisting of quaternary amines, cationic polyvinyl alcohols, cationic celluloses, and combinations thereof.

3. The polishing composition of claim 1, wherein X, in combination with attached carbon ¹ And X ² Formation of sp ² Hybrid carbon.

4. The polishing composition of claim 1, wherein the polishing composition further comprises a rate enhancing agent.

5. The polishing composition of claim 1, wherein the abrasive is present in the polishing composition at a concentration of 0.001 wt.% to 5 wt.%.

6. The polishing composition of claim 1, wherein the self-stopping agent is selected from the group consisting of maltol, ethyl maltol, kojic acid, deferiprone, salts thereof, and combinations thereof.

7. The polishing composition of claim 1, wherein the self-stopping agent is present in the polishing composition at a concentration of 1 wt.% or less.

8. The polishing composition of claim 1, wherein Z is selected from phenyl, benzyl, naphthyl, azulene, anthracene, or pyrene.

9. The polishing composition of claim 1, wherein the cationic compound is a polymer comprising a quaternary amine monomer, and wherein the quaternary amine monomer is selected from the group consisting of vinylimidazolium, methacryloyloxyethyltrimethylammonium halide, diallyldimethylammonium halide, and combinations thereof.

10. The polishing composition of claim 9, wherein the cationic compound is an oligomer comprising a quaternary amine monomer, and wherein the quaternary amine monomer is selected from the group consisting of vinylimidazolium, methacryloyloxyethyltrimethylammonium halide, diallyldimethylammonium halide, and combinations thereof.

11. The polishing composition of claim 1, wherein the cationic compound is a cationic polymer selected from the group consisting of: 2- (dimethylamino) ethyl methacrylate, diallyldimethylammonium, poly (vinylimidazolium), poly (methacryloyloxyethyltrimethylammonium) halide, poly (diallyldimethylammonium) halide, polyquaternium-2, polyquaternium-11, polyquaternium-16, polyquaternium-46, polyquaternium-44, luviquat Supreme, luviquat Hold, luviquat UltraCare, luviquat FC370, luviquat FC 550, luviquat FC 552, luviquat Excellence, and combinations thereof.

12. The polishing composition of claim 11, wherein the cationic compound is a cationic oligomer selected from the group consisting of: 2- (dimethylamino) ethyl methacrylate, diallyldimethylammonium, poly (vinylimidazolium), poly (methacryloyloxyethyltrimethylammonium) halide, poly (diallyldimethylammonium) halide, polyquaternium-2, polyquaternium-11, polyquaternium-16, polyquaternium-46, polyquaternium-44, luviquat Supreme, luviquat Hold, luviquat UltraCare, luviquat FC370, luviquat FC 550, luviquat FC 552, luviquat Excellence, and combinations thereof.

13. The polishing composition of claim 1, wherein the pH of the polishing composition is 6.0 to 8.5.

14. The polishing composition of claim 1, wherein the pH of the polishing composition is 3 to 5.

15. A method of chemically-mechanically polishing a substrate comprising:

(i) Providing a substrate, wherein the substrate comprises a patterned dielectric layer on a surface of the substrate,

(ii) A polishing pad is provided that is capable of polishing a substrate,

(iii) Providing a chemical mechanical polishing composition of claim 1,

(iv) Contacting the substrate with the polishing pad and the chemical-mechanical polishing composition, and

(v) Moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the patterned dielectric layer located on the surface of the substrate to polish the substrate.