CN118707807A - Patterned composition, patterned film, patterned substrate, semiconductor device and method for manufacturing the same - Google Patents

Abstract

Embodiments of the present application provide a patterning composition, a patterning film, a patterning substrate, a semiconductor device, and a method of manufacturing the same. The patterning composition comprises a base resin, a photoacid generator and an organic solvent, wherein the base resin comprises an acid-labile repeating unit, a first repeating unit derived from a first monomer with a specific structure and a second repeating unit derived from a second monomer with a specific structure, and the mole ratio of the first repeating unit and the second repeating unit in the base resin is 20% -33% and 20% -30%, respectively. By virtue of the good hydrophilicity provided by the first repeating unit and the etch resistance provided by the second repeating unit, a patterned film having good etch resistance and extremely low pattern defect rate can be produced using the patterning composition for use in the manufacture of semiconductor devices.

Description

Patterned composition, patterned film, patterned substrate, semiconductor device and manufacturing method thereof

Technical Field

The present application relates to the field of patterning technology, and in particular to a patterning composition, a patterning film, a patterning substrate, a semiconductor device and a manufacturing method thereof.

Background Art

As the integration of semiconductor integrated circuits continues to increase, the requirements for the critical dimension (CD) of chip patterning are also continuously reduced, and the control of pattern defects is becoming more and more important. For example, if there is a bridge defect between adjacent patterns in the pattern, it will greatly affect the transfer of the pattern to the substrate, and ultimately affect the preparation yield of semiconductor devices. However, the resin patterning materials used to form patterns in the current patterning process are difficult to balance good dry etching resistance and low pattern defects, which affects its wide application in the field of semiconductor manufacturing.

Summary of the invention

In view of this, the embodiments of the present application provide a patterned composition, a patterned film, a patterned substrate, a semiconductor device and a method for manufacturing the same. The patterned composition can be used to produce a patterned film with good dry etching resistance and low pattern defect rate.

Specifically, the first aspect of the embodiment of the present application provides a patterned composition, comprising a base resin, a photoacid generator and an organic solvent, wherein the base resin comprises an acid-labile repeating unit, a first repeating unit derived from a monomer represented by formula (A) and a second repeating unit derived from a second monomer; the second monomer comprises one or more substances represented by formula (B1) to formula (B5);

Formula (A) Formula (B1)

Formula (B2) Formula (B3)

Formula (B4) Formula (B5)

Furthermore, in the base resin, the molar ratio of the first repeating unit is 20%-33%, and the molar ratio of the second repeating unit is 20%-30%.

In the above-mentioned base resin, the structure of the first repeating unit helps to improve the hydrophilicity of the resin, and the structure of the second repeating unit can help to improve the dry etching resistance of the resin, and the molar mass proportions of the two in the base resin are controlled in the range of 20%-33% and 20%-30%, respectively, which can help the two to better play a synergistic role, so that the patterned composition using the base resin can obtain a patterned film with good etching resistance and low pattern defect rate.

The second aspect of the embodiment of the present application provides a patterned film, which is formed by the patterned composition described in the first aspect of the embodiment of the present application. After the patterned composition is applied, it can be transformed into a patterned film with a certain pattern through a patterning process including exposure, baking, development and other steps.

The third aspect of the embodiment of the present application provides a patterned substrate, wherein the pattern on the patterned substrate is formed using the patterned composition described in the first aspect of the embodiment of the present application. The pattern on the patterned substrate can be formed by transferring the pattern of the patterned film formed by the above-mentioned patterned composition to the substrate. The patterned substrate can be used for the preparation of semiconductor devices such as chips to improve the manufacturing accuracy and quality of the device.

The fourth aspect of the embodiment of the present application provides a semiconductor device, which uses the patterned film described in the second aspect of the embodiment of the present application, or uses the patterned substrate described in the third aspect of the embodiment of the present application. The semiconductor device may include a patterned substrate and a device structure formed on the patterned substrate.

The present application also provides a method for preparing a semiconductor device, comprising:

Applying the patterned composition described in the first aspect of the embodiment of the present application on a substrate to form a film layer on the substrate;

The film layer is selectively exposed and baked in sequence, and then developed with a developer to form a patterned film on the substrate.

In some embodiments of the present application, after forming the patterned film, the method further comprises: transferring the pattern of the patterned film to a substrate to obtain a patterned substrate.

Furthermore, after obtaining the patterned substrate, the method may further include: forming a structure required for the semiconductor device on the patterned substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a patterning process flow according to an embodiment of the present application.

FIG. 2 is a schematic diagram of a patterning process flow provided in another embodiment of the present application.

FIG. 3 shows a scanning electron microscope (SEM) photograph of a patterned film obtained by using the patterned composition of Example 3 of the present application.

FIG. 4 shows a SEM photograph of a patterned film obtained by using the patterned composition of Comparative Example 1 of the present application.

DETAILED DESCRIPTION

The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

In the process of manufacturing semiconductor devices, patterning is an important process. The patterning process generally includes the following steps: (1) coating a patterning composition (such as a chemically amplified photoresist including a base resin and a photoacid generator) on a substrate to form a patterned material film layer; (2) selectively exposing the patterned material film layer through an exposure source through a mask with a predetermined pattern, causing the photoacid generator in the exposure area to decompose and generate acid; in the baking process after exposure, the photoacid catalyzes the deprotection of the acid-labile protecting groups in the base resin in the exposure area, thereby increasing the polarity of the base resin in the exposure area, thereby producing a difference in the solubility of the developer in the exposure area and the unexposed area; (3) after exposure and baking, the patterned material film layer is developed with a developer, leaving a patterned film with the same or opposite pattern as the mask on the substrate. The substrate can be selectively etched using this patterned film as a mask. Finally, the desired pattern is achieved on the substrate.

At present, most commonly used patterning compositions are patterning materials containing polyacrylate resins, which are difficult to achieve both good etching resistance and low pattern defects, affecting their wide application in the field of semiconductor manufacturing. In view of this, the embodiments of the present application provide a resin patterning composition that can achieve both good etching resistance and low pattern defects.

The present application provides a patterned composition, which includes a base resin, a photoacid generator and an organic solvent, wherein the base resin includes an acid-labile repeating unit, a first repeating unit derived from a monomer represented by formula (A), and a second repeating unit derived from a second monomer; the second monomer includes one or more substances represented by formula (B1) to formula (B5);

Formula (A) Formula (B1)

Formula (B2) Formula (B3)

Formula (B4) Formula (B5)

Furthermore, in the base resin, the molar ratio of the first repeating unit is 20%-33%, and the molar ratio of the second repeating unit is 20%-30%.

The monomer shown in formula (A) and the second monomer are both lactone monomers, wherein the lactone ring of formula (A) has an ether oxygen bond, and the monomer has strong hydrophilicity. The first repeating unit derived from the monomer of formula (A) can ensure that the base resin has a certain hydrophilicity, so that the patterned composition containing the base resin is not easy to produce graphic bridging defects. The ratio of the total number of atoms in the second repeating unit derived from the second monomer to the difference between the number of carbon atoms and the number of oxygen atoms (i.e., O.N.) is large, and the proportion of carbon atoms on the lactone ring (i.e., the ratio of the number of carbon atoms on the lactone ring to the number of all atoms on the lactone ring) is high, so that the base resin with the second repeating unit can help improve the dry etching resistance of the above-mentioned patterned material. Moreover, controlling the molar proportions of the first and second repeating units in the base resin to be within the range of 20%-33% and 20-30%, respectively, can ensure that they play a good synergistic role, so as to ensure that the patterned film formed by the patterned composition has both low defect rate and good etching resistance.

The above-mentioned term "dry etching resistance" mainly refers to the tolerance of the patterned material to the etching gas used for dry etching, that is, the etching rate of the patterned material by the etching gas is not high. The etching gas may include but is not limited to one or more of fluorine-containing gases (such as CF ₄ , CHF ₃ , NF ₃ , SF ₆ , etc.), hydrogen (H ₂ ), etc. The above-mentioned "defect rate" refers to the proportion of samples with pattern defects among multiple patterned thin film samples formed using the above-mentioned patterned material.

Wherein, the structure of the first repeating unit corresponding to the monomer represented by formula (A) can be Taking the second monomer as the substance represented by formula (B1) as an example, the structure of the second repeating unit is illustrated as follows: .

In the present application, the molar proportion of the first repeating unit and the second repeating unit specifically refers to their molar proportion in all repeating units of the base resin. Specifically, in the above base resin, the molar proportion of the first repeating unit can be 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 32.5%, etc. The molar proportion of the second repeating unit can be 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%, etc.

In some embodiments of the present application, in the base resin, the molar ratio of the first repeating unit is 22%-28%. In the base resin, the molar ratio of the second repeating unit is 24%-30%. In this case, the use of a base resin containing such a first repeating unit and a second repeating unit can ensure that the resin composition can better balance a lower pattern defect rate and a lower etching rate.

In the embodiment of the present application, in the base resin, the sum of the molar proportions of the first repeating unit and the second repeating unit is 40%-60%, for example, specifically 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, or 59%, etc. In some embodiments, in the base resin, the sum of the molar proportions of the first repeating unit and the second repeating unit is 45%-58%, and further can be 46%-58%, or 46%-56%, etc. In this way, the first repeating unit and the second repeating unit can better play a synergistic role in the above-mentioned resin composition to ensure that the film layer formed by the patterned composition has better etching resistance and is substantially free of graphic defects.

In an embodiment of the present application, the molar ratio of the first repeating unit to the second repeating unit is 1:(0.67-1.5), for example, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, etc.

In the embodiment of the present application, the molecular weight distribution index PDI of the above base resin is between 1-2.

In the present application, an acid-labile repeating unit refers to a repeating unit corresponding to a monomer with an acid-labile group. The acid-labile group can undergo bond cleavage under the catalytic action of an acid (usually accompanied by heat treatment) to form a polar group (such as a carboxylic acid group or a hydroxyl group). The bond cleavage of the acid-labile group usually occurs during post-exposure baking. The acid-labile group may also be referred to as an "acid-labile protecting group" or an "acid-cleavable group".

In some embodiments of the present application, the acid-labile repeating unit may have the following structure: , wherein R ₁ includes a hydrogen atom or a methyl group (-CH ₃ ), and R ₂ includes an acid-labile group. The present application does not specifically limit the acid-labile group, which may include a monocyclic structure (such as a cyclopentyl ring, a cyclohexyl ring), or a polycyclic structure (such as an adamantane ring), or a substituted or unsubstituted tertiary alkyl group (such as a tert-butyl group), etc.

In some embodiments of the present application, the acid-labile repeating unit comprises a repeating unit derived from at least one of the following monomers:

.

Among them, monomers C1 to C4 have a single-ring deprotection group, and monomers C5 to C8 have a multi-ring deprotection group.

In the embodiment of the present application, the molar proportion of the acid-unstable repeating unit in the base resin can be 25%-60%. Wherein, in some possible embodiments, when the above-mentioned base resin only contains the acid-unstable repeating unit, the first repeating unit and the second repeating unit, the molar proportion of the acid-unstable repeating unit in all the repeating units of the base resin is 35%-60%, for example, specifically 36%, 38%, 40%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, or 59%, etc. In some other possible embodiments, the above-mentioned base resin may include other repeating units except the acid-unstable repeating unit, the first repeating unit and the second repeating unit. Controlling the acid-unstable repeating unit in the base resin to have an appropriate molar proportion can make the base resin have more repeating units with alkali-soluble groups after acid-catalyzed baking, ensuring that it has good developability.

In some embodiments of the present application, the base resin further includes other repeating units with a molar proportion of less than 15%. The other repeating units are different from the acid-labile repeating units, the first repeating units, and the second repeating units. Exemplarily, the molar proportion of other repeating units in the base resin may be less than 10%, less than 8%, less than 6%, or less than 5%, etc. In some embodiments, the other repeating units include repeating units derived from monomers represented by formula (D):

Formula (D).

The introduction of the repeating unit corresponding to the monomer of formula (D) into the base resin can further increase the etching resistance of the film layer formed by the patterned composition, and can increase the adhesion of the patterned composition to the substrate to which it is attached, and the solubility of the base resin in organic solvents.

The above-mentioned base resin can be obtained by copolymerizing the corresponding monomer raw materials in the presence of an initiator. The monomer raw materials used to synthesize the base resin include at least the monomer represented by formula (A), at least one second monomer represented by the above-mentioned formula (B1) to formula (B5), and an acid-labile monomer. In some cases, other monomers may also be included, such as the monomer represented by the above-mentioned formula (D).

In some embodiments of the present application, the above-mentioned base resin can be prepared in the following manner: under the protection of an inert gas, the corresponding monomer raw materials are mixed with a solvent, and an initiator is added to carry out a polymerization reaction to obtain the base resin.

Among them, the initiator can be a thermal initiator, such as one or more of aqueous initiators such as potassium persulfate, sodium persulfate, ammonium persulfate, or one or more of oily initiators such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate, azobisisoheptanenitrile, benzoyl peroxide, etc. The aqueous initiator or the oily initiator can be selected according to the monomer raw material and the solvent used. In some embodiments, the initiator is AIBN and the solvent used is 1,4-dioxane. Among them, the temperature of the polymerization reaction can be 50-100°C, for example, specifically 60°C, 70°C or 80°C. The polymerization reaction time can be regulated according to the molecular weight of the desired base resin. In addition, after the polymerization reaction is completed, the reaction material containing the base resin can be placed in a precipitant (such as methanol, ethanol, isopropanol, etc.) for sedimentation to precipitate the desired resin.

The photoacid generator in the resin composition can generate photoacid under the irradiation of an exposure source. There is no special requirement for the photoacid generator in the present application. Optionally, the photoacid generator can include a small molecule sulfonium salt, which can include a sulfonium cation and an anion containing an acidic group.

In some embodiments of the present application, the small molecule sulfonium salt used as a photoacid generator may have a structure shown in the following formula (E):

Formula (E)

Wherein, R ₃ , R ₄ , R ₅ are independently selected from substituted or unsubstituted monovalent hydrocarbon groups containing or not containing heteroatom linking groups, any two of R ₃ , R ₄ , R ₅ can be bonded to each other to form a ring, and X ^- is an anion containing an acidic group. Wherein, the acidic group can include one or more of sulfonate, sulfate, carbonate, fluorosulfonamide, etc. The heteroatom linking group can be one or more of ether bond (-O-), thioether bond (-S-), carbonyl (-C(=O)-), ester bond (-C(=O)-O-), oxycarbonyl (-OCO-), imino bond (-NH-), amide bond (-NHCO-), etc. Wherein, the monovalent hydrocarbon group can include one or more of chain alkyl, cycloalkyl, chain or cyclic alkenyl, chain or cyclic alkynyl, aryl, and these hydrocarbon groups can be unsubstituted or substituted (for example, containing halogen atoms).

In some embodiments, in the onium salt repeating unit represented by formula (1), the sulfonium cation may include any of the following structures.

In some embodiments, in formula (E), ^X- is Ra ^- _CF2 - _SO3- , wherein ^Ra is a substituted or unsubstituted monovalent hydrocarbon group containing or not containing a heteroatom linking group. In some cases, ^Ra is a fluoroalkyl group, or ROC ⁽ =O)-, or RC(=O)-O-, wherein R is a substituted or unsubstituted alkyl group or cycloalkyl group.

Exemplarily, the photoacid generator includes, but is not limited to, one or more of the following substances:

.

In the embodiment of the present application, the mass of the photoacid generator is 0.5%-20% of the mass of the base resin. Controlling the mass ratio of the photoacid generator to the base resin within an appropriate range can ensure that the acid-labile groups in the patterned composition are fully bond-broken during the post-exposure baking process, and will not increase the acid diffusion degree of the patterned composition during the post-exposure baking process due to the excessive mass proportion of the photoacid generator. Exemplarily, the mass of the photoacid generator is 1%, 2%, 5%, 6%, 8%, 10%, 15%, 18%, 20%, etc. of the mass of the base resin.

In some embodiments of the present application, the patterning composition further contains an acid quencher, wherein the presence of the acid quencher can help quench the excessive photo-generated acid generated by the base resin during exposure to light, thereby inhibiting the diffusion of the photo-acid and avoiding a reduction in the resolution of the pattern formed by the patterning composition.

There is no special requirement for the structure of the acid quencher in this application. Exemplarily, the acid quencher may include at least one of the following substances:

.

Optionally, the mass of the acid quencher does not exceed 12% of the total mass of the base resin in the patterning composition, for example, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 9%, 10%, etc.

In order to improve the comprehensive performance of the patterned composition, in some cases, other additives may be included in the above-mentioned patterned composition. For example, in some embodiments of the present application, the patterned composition also includes a fluorine-containing polymer additive. The fluorine-containing polymer additive can reduce the surface energy of the film layer formed by the above-mentioned patterned composition to give it hydrophobicity, thereby preventing the above-mentioned patterned composition from leaving water stains on the surface of the coated substrate and preventing the substances in the patterned composition from contaminating the lens of the patterned device. The content of the fluorine-containing polymer additive in the patterned composition can be adjusted according to actual needs.

For example, the fluorine-containing polymer may have a structure represented by the following formula (F):

Formula (F).

In some embodiments of the present application, the organic solvent includes one or more of ketone solvents, ester solvents, ether solvents, and alcohol solvents. For example, ketone solvents may include, but are not limited to, one or more of 2-heptanone, methyl-2-n-pentanone, cyclohexanone, cyclopentanone, etc. Ester solvents may include one or more of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, butyl acetate, 3-methoxypropionic acid methyl ester, γ-butyrolactone (GBL), 2-hydroxyisobutyric acid methyl ester (HBM), etc. Ether solvents may include, but are not limited to, one or more of propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. Alcohol solvents may include, but are not limited to, one or more of isopropanol, 3-methoxybutanol, etc.

Optionally, in the embodiment of the present application, the solid content in the above-mentioned patterned composition is 2wt%-8wt%. Controlling the solid content in the patterned composition within an appropriate range can help ensure that the above-mentioned patterned composition has a suitable viscosity and coating thickness. Wherein, the solid content refers to the sum of the mass percentages of other components in the above-mentioned patterned composition except the solvent.

The above-mentioned patterned composition in the embodiment of the present application has good coating performance and is easy to coat and form a film. The formed coating film layer has a smooth surface, the film thickness is easy to adjust, and the development conditions meet the requirements of the patterning process, which is convenient for application in the field of semiconductor patterning.

The present application also provides an application of the above-mentioned patterning composition in pattern formation. The above-mentioned patterning composition can be applied to semiconductor patterning process, and after exposure, baking, and development, it is transformed into a high-quality, etching-resistant patterned film, and based on this, a semiconductor device (such as a chip) with high quality reliability and high precision is formed.

The present application also provides a patterning method, as shown in FIG. 1 and FIG. 2 , wherein the patterning process includes:

S01, coating the patterned composition of the embodiment of the present application on a substrate to form a patterned material film layer on the substrate;

S02, selectively exposing and baking the film layer in sequence, and then developing it with a developer to form a patterned film on the substrate.

The substrate to be coated with the patterned composition can be selected according to specific needs, for example, it can be a silicon wafer, or a silicon wafer covered by other film layers. Other film layers may include, but are not limited to, one or more of bottom anti-reflective coating (BARC), epitaxial layer, metal layer, dielectric layer (such as SiO ₂ or Si ₃ N ₄ ), etc. Usually, other film layers can be obtained by pre-treating the substrate, and the pre-treatment method can be: subjecting the silicon wafer substrate to O ₂ plasma surface hydrophilic activation; or washing in Piranha solution (H ₂ O: 30% ammonia water: 30% H ₂ O ₂ = 5: 1: 1) for 15-20 minutes, and then washing with deionized water and isopropanol to complete the hydrophilic treatment; or using evaporation or spin coating to cover hexamethyldisilazane (HMDS) on the substrate to perform surface hydrophobic treatment on the substrate.

The coating method of the above-mentioned patterned composition includes, but is not limited to, spin coating, dip coating, brush coating, spray coating, roller coating, etc. In some possible embodiments, the coating is specifically spin coating. Depending on the size of the substrate, an appropriate volume of the above-mentioned patterned composition can be taken and spin-coated on the substrate to form a patterned material film layer of a certain thickness. Exemplarily, the coating thickness of the patterned composition can be in the range of 5nm-2μm.

In some embodiments of the present application, after applying the above-mentioned patterned composition, pre-baking is also performed to minimize the solvent content in the patterned composition. Pre-baking can be performed on a heating plate or in an oven. The typical temperature of the pre-baking can be 60-150°C, and the time is 10 seconds to 30 minutes; further, the pre-baking temperature is 80-120°C, and the time is 30 seconds to 10 minutes. In some embodiments, the pre-baking temperature is 90°C and the pre-baking time is 60 seconds.

In step S02, the exposure source used for the selective exposure may be a light source with a wavelength below 400nm, or an electron beam, etc. When performing the selective exposure, a mask plate with a predetermined pattern is placed above the aforementioned patterned material film layer, and the exposure source irradiates the patterned material film layer through the mask plate to achieve selective exposure (i.e., patterned exposure). After the aforementioned patterned material film layer is selectively exposed, the photoacid generator in the exposed area decomposes to generate acid, so that the exposed area and the non-exposed area have a solubility difference in the developer during the post-exposure baking process.

Post Exposure Bake (PEB) is performed after exposure, which can promote the deprotection of the acid-labile repeating units of the base resin in the exposure area of the acid-catalyzed patterned material film layer generated in the above-mentioned exposure process, thereby achieving polarity reversal of the base resin, thereby causing a solubility difference between the exposed area and the non-exposed area of the film layer to the developer. Optionally, the typical temperature of the baking can be 60-150°C, and the duration is 10 seconds to 30 minutes. Further, the baking temperature is 80-120°C, and the duration is 30 seconds to 10 minutes. In some embodiments, the baking temperature is 80°C, and the duration is 60 seconds. In another embodiment, the baking temperature is 95°C, and the duration is 60 seconds.

Since the chemical properties of the exposed portion of the patterned material film layer change, the solubility in the developer is different from that of the unexposed portion. Therefore, the selective dissolution and patterned appearance of the patterned material film layer can be achieved by using a developer to treat the patterned material film layer after exposure and baking. If the exposed portion of the patterned material film layer is removed by the developer after being treated with the developer, the development can be called "positive development" to form a positive pattern on the substrate (as shown in Figure 1), which is basically the same as the pattern of the exposure mask. If the unexposed area of the patterned material film layer is removed by the developer after being treated with the developer, the development can be called "negative development" to form a negative pattern on the substrate, which is basically complementary to the pattern of the exposure mask (as shown in Figure 2).

The development process can select a suitable developer according to the properties of the patterned material. In some embodiments of the present application, the developer is an alkaline aqueous solution. The exposed area of the patterned material film layer will dissolve in the alkaline developer while the unexposed area is almost insoluble in the alkaline developer, thereby forming a target positive pattern on the substrate. Among them, the alkaline substance in the alkaline aqueous solution includes one or more of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), etc.

In another embodiment of the present application, the developer is an organic solvent. The organic solvent can dissolve the exposed area of the patterned material film layer and make the unexposed area insoluble, thereby forming a target negative pattern on the substrate. Among them, the organic solvent used for development can include but is not limited to one or more of ketone solvents, alcohol solvents, ether solvents, ester solvents, etc. Ketones can be, for example, cyclohexanone and methyl-2-n-pentyl ketone. Alcohols can be, for example, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, 1,3-butanediol, etc. Ethers can be, for example, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc. Esters can be, for example, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate, γ-butyrolactone, etc.

The development may be performed by common methods such as dipping or spraying. The contact time between the developer and the patterned material film layer (ie, the development time) may be 3 seconds to 180 seconds, and further may be 5 seconds to 120 seconds.

In addition, a water rinse process can be optionally added after development, and the rinse time can be 20s-120s. Rinse can make the film layer cleaner; a baking process (i.e., post-baking) can also be optionally added. Post-baking can harden the pattern structure, making the structure more stable and less prone to collapse. The post-baking temperature can be between 60-200°C and the time can be between 20s-120s. In some embodiments, the post-baking is performed at 90°C for 60 seconds.

After development, the obtained patterned film may be observed using an electron microscope or an atomic force microscope to observe whether there are pattern defects and to obtain parameters such as pattern resolution and line width roughness.

In the embodiment of the present application, the defect rate of the patterned film formed by using the above patterned composition is 0. This indicates that the yield rate of the patterned film is very high.

In the embodiment of the present application, the etching rate of the etching gas (specifically comprising a mixed gas of CHF ₃ and CF ₄ with a gas flow ratio of 2:1) on the above-mentioned patterned film is below 1000 Å/min. The patterned film of the embodiment of the present application has good etching resistance, and the pattern quality of the patterned substrate subsequently formed with the mask is good and the line width roughness is low.

In some embodiments of the present application, after the above step S02, the following step S03 is also included: using the above patterned film as a mask, etching the substrate to transfer the pattern of the patterned film to the substrate to obtain a patterned substrate.

The above-mentioned patterned film has good etching resistance in the etching step, and can selectively protect the substrate material located thereunder. After etching under certain conditions, the substrate material not protected by the patterned film can be etched away, and the substrate material protected by the patterned film can be retained, and finally a pattern is formed on the substrate material, that is, the pattern of the patterned film is transferred to the substrate. Among them, the etching medium used in the etching process can be a fluorine-containing gas. The fluorine-containing gas can include, but is not limited to, one or more of _CF4 , _CHF3 , _NF3 , _SF6 , etc. Generally, it is usually necessary to remove the patterned film (for example, by ashing) in the future to prepare other functional layers on the patterned substrate.

The patterning method provided in the embodiment of the present application can be applied to the patterning process of the semiconductor integrated circuit manufacturing process by adopting the patterning composition of the embodiment of the present application to obtain a chip pattern structure with high resolution and low pattern defect rate, which is conducive to the high-integration and high-precision development of semiconductors.

The present application also provides a patterned film, which is formed by the patterned composition or obtained by the patterning method described above. The patterned film can be used as a high-precision mask in the patterning process of manufacturing integrated circuits, and the pattern of the patterned film can be transferred to a substrate such as a silicon wafer by etching to form a preset pattern on the substrate.

Since the patterned film is formed by the above-mentioned patterned composition provided in the embodiment of the present application, it has a low defect rate (even the pattern defect rate is 0), and at the same time it has good etching resistance. The etching rate of the fluorine-containing gas commonly used in dry etching is low. Therefore, the patterned film can be used to produce a patterned substrate with a low pattern defect rate.

The present application also provides a patterned substrate, wherein the pattern on the patterned substrate is formed by the patterned composition of the present application or obtained by the patterning method. The patterned substrate can be used for the preparation of semiconductor devices (such as chips), improving the manufacturing accuracy and quality of the devices, and thus improving the performance of the semiconductor devices.

In some embodiments of the present application, the method for preparing the patterned substrate includes:

The patterned film is formed on a substrate; and the pattern of the patterned film is transferred to the substrate to obtain a patterned substrate.

Among them, the process of forming a patterned film can refer to the description of the previous text of this application, and will not be repeated here. "Transferring the pattern of the patterned film to the substrate" can be achieved by selectively etching the substrate material under the masking action of the patterned film. Among them, etching can specifically be etching with a fluorine-containing gas, or ion etching, etc. The substrate material that is not protected by it is etched, and the etching speed of the protected part is slower than that of the unprotected part, and finally a pattern is formed on the substrate material, that is, the pattern is transferred to the substrate. For example, the patterned film can be used as a mask to etch other film layers on the substrate below it, so as to achieve patterning of other film layers, and the substrate also has the pattern of other film layers accordingly. It is also possible to directly etch the substrate on the basis of the other patterned film layers to achieve patterning of the substrate.

The present application also provides a semiconductor device, which uses the patterned substrate of the present application, or a preparation method thereof includes the patterning method of the present application. The semiconductor device has high manufacturing yield, high precision and stable performance.

The semiconductor device may include a chip, etc. In the process of preparing the chip, other functional layers may be prepared after completing the above patterning process.

Specifically, the semiconductor device provided in the embodiments of the present application can be used in terminal devices, such as tablet computers, laptop computers, mobile phones, digital cameras, wearable electronic devices, virtual reality devices, etc.

The present application also provides a method for preparing a semiconductor device, comprising:

A patterned substrate is prepared by the aforementioned patterning method;

The structure required for the semiconductor device is formed on the patterned substrate to obtain the semiconductor device.

The structure required for the semiconductor device can also be formed on the basis of the patterned film provided in the embodiment of the present application.

The embodiments of the present application are further described below with reference to a plurality of embodiments.

1. Preparation of base resin

Synthesis Example 1

A base resin, the preparation process of which is as follows:

Under nitrogen atmosphere, the first monomer represented by the above formula A (hereinafter referred to as A1), the second monomer represented by the formula (B1) (hereinafter referred to as B1), the acid unstable monomer represented by the formula (C4) (hereinafter referred to as C4), the acid unstable monomer represented by the formula (C7) (hereinafter referred to as C7), and the polar monomer represented by the formula (D) (hereinafter referred to as D) are mixed in a 1.4-dioxane solvent in a certain molar ratio, and after being fully stirred, a certain amount of initiator azobisisobutyronitrile (AIBN) is added, and the polymerization reaction is carried out at 85°C for 3 hours. After the reaction is completed, the obtained reaction solution is added dropwise to 5 times the volume of methanol for precipitation to obtain the desired resin product, which is recorded as r1.

The resin product r1 was subjected to H NMR and C NMR tests to obtain the molar proportion of the repeating units derived from each monomer in all the repeating units of the resin r1, and the results are summarized in the following Table 1. In addition, the weight average molecular weight _Mw and molecular weight distribution PDI of the resin product r1 were tested by gel permeation chromatography using polystyrene as a standard, and the results are summarized in Table 1.

The base resins of other synthesis examples or comparative synthesis examples were prepared by following the synthesis method of resin r1 described in the above synthesis example 1. The monomer raw materials required for synthesizing the base resin, the molar ratio of the corresponding repeating units of each monomer in the obtained base resin, the weight average molecular weight _Mw and the molecular weight distribution PDI of the base resin are summarized in Table 1.

Table 1

(II) Preparation of patterned composition

The raw materials required for preparing each patterned composition were weighed according to the formula shown in Table 2 below, and the raw materials were mixed in a mixed solvent consisting of PGMEA and GBL in a mass ratio of 9:1. After sufficient stirring, a patterned composition with a certain solid content was obtained.

(III) Patterning composition for patterning process

First, HMDS was uniformly covered on the surface of the silicon wafer by evaporation (evaporation temperature was 120°C, time was 50 seconds); then, the BARC composition was coated on the surface of the silicon wafer with HMDS evaporated, and heated and cured at 250°C for 60 seconds to form a BARC coating with a thickness of 980Å. Then, each patterned composition solution was spin-coated on the surface of the silicon substrate, and baked at 90°C for 60 seconds to remove most of the solvent, forming a patterned material film layer with a thickness of 950Å. Then, Ar F excimer laser was used as an exposure source, and the patterned material film layer was selectively exposed through a mask with a periodic line pattern (line width of 45nm, period size of 90nm (i.e., line spacing of 45nm)); and PEB baking was performed for 60 seconds at the temperature shown in Table 2 immediately after exposure. Finally, the patterned material film layer was immersion developed for 30 seconds using a TMAH aqueous solution with a concentration of 2.38wt%, and a patterned film with a periodic line pattern was formed on the BARC coating of the silicon wafer.

The best exposure energy (BE) of each patterned composition is summarized in Table 2 below. In addition, 99 patterned film samples were prepared using each patterned composition, and the exposure energy range was BE-4mJ~BE+4mJ. It was observed whether there were bridge defects between adjacent lines in each sample, and the number of patterned film samples with pattern bridge defects was recorded. The results are summarized in Table 2.

(IV) Evaluation of dry etching resistance:

The above-mentioned patterned compositions were spin-coated on Si substrates to form a patterned material film layer with a thickness of 300 nm, and a dry etching device was used to etch the patterned material film layer with a mixed gas of CF ₄ and CHF _3. The film thickness difference of the patterned material film layer before and after etching was tested, and the etching rate per minute was calculated. The results are also summarized in Table 2. The specific etching conditions are as follows: the pressure in the chamber is 12 mtorr, the RF power is 500 W; the CF ₄ gas flow rate is 40 sccm, the CHF ₃ gas flow rate is 80 sccm, and the N ₂ flow rate is 45 sccm; the etching time is 20 seconds.

Table 2

Among them, FIG3 shows a SEM photo of a patterned film obtained by using the patterned composition of Example 3 of the present application. FIG4 shows a SEM photo of a patterned film obtained by using the patterned composition of Comparative Example 1. From the comparison of FIG3 and FIG4, it can be seen that the pattern resolution (pitch resolution) of the patterned film obtained by Example 3 of the present application can reach 90nm; the width of each line is relatively uniform, and there is no bridging defect between adjacent lines. However, there are obvious bridging defects between some lines in the patterned film obtained in Comparative Example 1.

As can be seen from Table 2 above, the base resins in the patterned compositions used in Comparative Examples 1 and 2 do not simultaneously contain the repeating units derived from the first monomer and the second monomer required by the present application. From the comparison between Comparative Example 1 and Example 3, it can be seen that when the etching rate of the patterned material film layer made of the patterned composition of Comparative Example 1 is low (i.e., the etching resistance is good), the patterned film formed has bridging defects, which is unacceptable in the semiconductor field. From the comparison between Comparative Example 2 and Example 7 using the base resin r6, it can be seen that although the patterned film formed by the patterned composition of Comparative Example 2 does not have a pattern defect rate, it is very easy to be etched by fluorine-containing gas. The patterned composition of the embodiment that meets the requirements of the base resin of the present application can be made into a film layer that takes into account the requirements of low etching rate and zero pattern defects.

The above only expresses the exemplary embodiments of the present application, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be based on the attached claims.

It should be understood that the first, second and various numerical numbers involved in this document are only used for the convenience of description and are not used to limit the scope of this application. In this application, "and/or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character "/" generally indicates that the associated objects before and after are in an "or" relationship.

In the description of this application, unless otherwise specified, "multiple" means greater than or equal to two. "At least one" means one or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple, respectively.

In addition, the numerical range represented by "-" in this application refers to the range that includes the numerical values recorded before and after "-" as the minimum and maximum values, respectively. In this application, expressions about parameter ranges, such as "greater than or equal to (≥)", "less than or equal to (≤)", "above...", and "below..." all include the number itself. The numerical values and numerical ranges involved in the embodiments of this application are approximate values. Due to the influence of manufacturing processes/testing methods, etc., there may be a certain range of errors, which can be considered negligible by those skilled in the art.

Claims (14)

1. A patterning composition comprising a base resin, a photoacid generator, and an organic solvent, wherein the base resin comprises acid-labile repeat units, a first repeat unit derived from a monomer of formula (a), and a second repeat unit derived from a second monomer; the second monomer includes one or more of the substances represented by the formulas (B1) to (B5);

(A) (B1)

(B2)(B3)

(B4)(B5)

In the base resin, the molar ratio of the first repeating unit is 20% -33%, and the molar ratio of the second repeating unit is 20% -30%.

2. The patterning composition of claim 1 wherein the base resin has a molar ratio of the first repeating unit of 22% to 28% and/or a molar ratio of the second repeating unit of 24% to 30%.

3. The patterning composition of claim 1 wherein the base resin has a mole ratio of the sum of the first repeat unit and the second repeat unit of 45% to 58%.

4. The patterning composition of claim 1 wherein the acid labile repeat units are present in the base resin in a molar ratio of 25% to 60%.

5. The patterning composition of claim 1 wherein the acid labile repeat units comprise repeat units derived from at least one of the following monomers:

。

6. The patterning composition of any one of claims 1 to 5, further comprising other repeating units in the base resin at a molar ratio of less than 15%; wherein the other repeating unit includes a repeating unit derived from a monomer represented by formula (D):

Formula (D).

7. The patterning composition of claim 1 wherein the photoacid generator is present in an amount of 0.5% to 20% by mass of the base resin.

8. The patterning composition of claim 1 to 5, wherein the patterning composition further comprises an acid quencher.

9. The patterning composition of claim 1 to 5, it is characterized in that the method comprises the steps of, fluoropolymer additives are also included in the patterning composition.

10. The patterning composition of claim 1, wherein the organic solvent comprises one or more of a ketone solvent, an ester solvent, an ether solvent, and an alcohol solvent.

11. A patterned film formed from the patterning composition of any one of claims 1-10.

12. A patterned substrate, wherein the pattern on the patterned substrate is formed using the patterning composition of any one of claims 1-10.

13. A semiconductor device fabricated using the patterned thin film of claim 12 or using the patterned substrate of claim 12.

14. A method of manufacturing a semiconductor device, comprising:

Applying the patterning composition of any one of claims 1-10 to a substrate to form a film layer on the substrate;

and sequentially performing selective exposure and baking on the film layer, and then developing by using a developer to form a patterned film on the substrate.