CN118234890A - Film quality improver, method for forming thin film using same, semiconductor substrate manufactured thereby, and semiconductor device - Google Patents
Film quality improver, method for forming thin film using same, semiconductor substrate manufactured thereby, and semiconductor device Download PDFInfo
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Abstract
The present invention relates to a film quality improver, a method for forming a thin film using the same, a semiconductor substrate and a semiconductor device manufactured by the same, wherein a compound having a predetermined structure is provided as the film quality improver, and a shield region for a molybdenum-based thin film is formed on the substrate to reduce the deposition rate of the molybdenum-based thin film and control the growth rate of the thin film, thereby greatly improving the step coverage and the thickness uniformity of the thin film, reducing corrosion or deterioration, and improving the crystallinity of the thin film to improve the electrical characteristics of the thin film even when the thin film is formed on a substrate having a complex structure using a compound solid at normal temperature.
Description
Technical Field
The present invention relates to a film quality improver, a film forming method using the same, a semiconductor substrate and a semiconductor device manufactured thereby, and more particularly, to a film quality improver, a film forming method using the same, and a semiconductor substrate manufactured thereby, which form a molybdenum-based thin film shielding region on a substrate to reduce or increase a deposition rate of a molybdenum-based thin film, and appropriately adjust a film growth rate to greatly improve a step coverage (step coverage), thickness uniformity of the thin film, specific resistance, and other film qualities when forming a thin film on a substrate having a complex structure or using a solid precursor to form a thin film at normal temperature.
Background
Molybdenum (Mo) is extremely excellent in chemical and thermal stability, has high conductivity and low resistivity (bulk resistivity ρ=0.57× -5 Ω·cm), and has been attracting attention as a material meeting the demands of recent device refinement, low power consumption, high productivity, and the like.
In particular, molybdenum is being applied as an electrode, a diffusion preventing film (diffusion barrier), a gas sensor, a catalyst substance, particularly, a molybdenum-containing thin film, which is attracting attention as a two-dimensional semiconductor substance in place of a graphene material when various semiconductor, display metal processes are performed, and research on its application is rapidly proceeding.
A representative molybdenum compound used for forming a molybdenum-containing film is molybdenum chloride (MoCl 5). However, thin Solid Films,166,149 (1988) have reported that they have disadvantages such as low deposition rate, high chlorine content, and film contamination due to hydrogen chloride or the like, and particularly have disadvantages such as particle contamination and inability to uniformly vaporize the precursor as a Solid compound.
In addition, although imino compounds such as Mo (NtBu) 2(NiPr2)2 reported in chem.vap. Deposition (2008) 14,71 are known, they have poor thermal stability and have a disadvantage in that the decomposition of the ligand in the process is not thorough due to the high stability of the imino ligand between the molybdenum central metal and nitrogen based on pi-bond, which is very serious in carbon contamination.
U.S. patent publication nos. 4,431,708 and j.de Phys.iv 2 (C2), 865 report molybdenum-containing films produced by deposition using Mo (CO) 6 compounds having a high vapor pressure, but are likely to have uneven vaporization characteristics, low thermal stability, and particle problems as solid compounds at ordinary temperatures.
Therefore, there is a need for development of a thin film forming method capable of forming a thin film having a complicated structure even when halogen (halogen) or the like which adversely affects a semiconductor and a display device is not contained in the thin film and in a solid form at normal temperature, and of greatly improving step coverage and uniformity of film thickness, a semiconductor substrate and the like manufactured thereby.
Disclosure of Invention
Problems to be solved by the invention
In order to solve the above-described problems of the prior art, an object of the present invention is to provide a film quality improver which can greatly improve the step coverage, the thickness uniformity of the film, the specific resistance, and other film qualities when a film is formed on a substrate having a complicated structure or a film is formed using a solid precursor at normal temperature, by forming a shield region for a molybdenum-based film on the substrate to reduce or increase the deposition rate of the molybdenum-based film, and to provide a film quality improver using the film formation method and a semiconductor substrate manufactured by the film quality improver.
The purpose of the present invention is to improve the density and electrical characteristics of a thin film by improving the crystallinity of the thin film.
The above and other objects of the present invention can be achieved in whole by the present invention described below.
Means for solving the problems
In order to achieve the above object, the present invention provides a film quality improver for a molybdenum-based thin film comprising molybdenum, molybdenum oxide or molybdenum nitride on a substrate, the film quality improver being a saturated compound represented by the following chemical formula 1,
[ Chemical formula 1]
Wherein, a is carbon (C) or silicon (Si), X is fluorine (F), chlorine (Cl), bromine (Br) or iodine (I), R 1 and R 3 are independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine, R 2 is independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine, iodine or a functional group having the formula Br 4R5R6, B is carbon or silicon, and R 4, R 5 and R 6 are independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine.
The refractive index (a) of the film quality improver may be in the range of 1.38 to 1.72, and the value (b/a) obtained by dividing the vapor pressure (25 ℃ C., mmHg, b) by the refractive index (a) may be in the range of 0.003 to 0.043.
The film quality improver can be the following compound: the integral value of the peak top of the newly generated peak in the 1 H-NMR spectrum measured after mixing and pressurizing the film quality improver and the molybdenum precursor in a molar ratio of 1:1 is less than 0.1% with respect to the 1 H-NMR spectrum of the film quality improver.
Wherein the molybdenum precursor may be solid or liquid at 20 ℃ and 1 bar.
The film quality improver can provide a shielding region for a molybdenum-based film.
The shielding region for a molybdenum-based thin film may be formed on a substrate on which the molybdenum-based thin film is to be formed.
The shielding region for the molybdenum-based film does not remain in the molybdenum-based film, and the molybdenum-based film may contain 1% or less of carbon, silicon, and a halogen compound.
The molybdenum-based film may be used as a diffusion preventing film (diffusion barrier) or an electrode (electrode).
In addition, the present invention provides a method for forming a molybdenum-based thin film, comprising the steps of: injecting a film quality improver of a saturated structure represented by the following chemical formula 1 into a chamber and into a surface of a loaded substrate;
[ chemical formula 1]
Wherein, the A is carbon or silicon, the X is fluorine, chlorine, bromine or iodine, the R 1 and the R 3 are independently hydrogen, alkyl with 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine, the R 2 is independently hydrogen, alkyl with 1 to 5 carbon atoms, fluorine, chlorine, bromine, iodine or a functional group with the formula BR 4R5R6, the B is carbon or silicon, the R 4, the R 5 and the R 6 are independently hydrogen, alkyl with 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine.
The molybdenum-based thin film forming method may include: step i-a: vaporizing the film quality improver to form a shielded region on a surface of a substrate loaded in a chamber; step ii-a: purging the interior of the chamber with a purge gas for a first time; step iii-a: vaporizing and adsorbing a molybdenum precursor to a region that is free of the shielded region; step iv-a: purging the interior of the chamber a second time with a purge gas; step v-a: supplying a reaction gas into the chamber; step vi-a: and purging the interior of the chamber with a purge gas a third time.
In addition, the molybdenum-based thin film forming method may include: step i-b: vaporizing and adsorbing a molybdenum precursor to a surface of a substrate loaded in a chamber; step ii-b: purging the interior of the chamber with a purge gas for a first time; step iii-b: vaporizing and injecting the film quality improver to the surface of a substrate loaded in a chamber; step iv-b: purging the interior of the chamber a second time with a purge gas; step v-b: supplying a reaction gas into the chamber; step vi-b: and purging the interior of the chamber with a purge gas a third time.
The molybdenum precursor may be solid or liquid at 20 ℃ and 1bar, and may be a molybdenum precursor having a vapor pressure of 0.1mTorr to 100Torr at 30 ℃.
The molybdenum precursor may be at least one selected from the group consisting of compounds represented by chemical formulas 2 to 36 below,
[ Chemical formula 2] to [ chemical formula 19]
[ Chemical formula 20] to [ chemical formula 32]
[ Chemical formulas 33] to [ chemical formula 36]
In the chemical formulas 2 to 36, the line is a bond, the intersection point of the bond and the bond of the other element is carbon, hydrogen in an amount satisfying the valence of the carbon is omitted, R ' and R "are each hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ' may be connected to an adjacent R '.
The chamber may be an Atomic Layer Deposition (ALD) chamber or a Chemical Vapor Deposition (CVD) chamber.
The molybdenum-based thin film forming method may include a step of performing a plasma post-treatment after vaporizing and injecting the film quality improver or molybdenum precursor.
In said step ii) and said step iv, the amount of purge gas injected into the interior of each chamber may be from 10 to 100,000 times the volume of membrane conditioner charged.
The reactant gases, the film quality improver, and the molybdenum precursor may be transferred into the chamber by a vapor phase flow control (VFC) method, a Direct Liquid Injection (DLI) method, or a liquid transfer system (LDS) method.
The substrate loaded in the chamber is heated to 50 to 400 ℃, and the ratio of the in-chamber injection amount (mg/cycle) of the film quality improver and the molybdenum precursor may be 1:1.5 to 1:20.
The reaction gas may be a reducing agent, nitriding agent or oxidizing agent.
The deposition temperature of the molybdenum-based thin film forming method may be 50 to 700 ℃.
The molybdenum-based film may be an oxide film, a nitride film, or a metal film.
The present invention also provides a semiconductor substrate manufactured by the above-described method for forming a molybdenum-based thin film.
The molybdenum-based film may be a multilayer structure of two or three layers.
In addition, the invention provides a semiconductor device comprising the semiconductor substrate.
The semiconductor substrate may be a low-resistance metal Gate interconnect (low RESISTIVE METAL GATE interconnects), a high-aspect ratio 3D metal-insulator-metal (MIM) capacitor (HIGH ASPECT ratio 3D metal-insulator-metal capacitor), a DRAM trench capacitor (DRAM TRENCH capacitor), a 3D full-surrounding Gate (GAA), or a 3D NAND.
Effects of the invention
According to the present invention, the film quality improver forms a shielding region for a molybdenum-based thin film on a substrate to reduce the deposition rate of the molybdenum-based thin film, and appropriately adjusts the film growth rate, thereby improving the step coverage even when a thin film is formed using a solid compound at normal temperature on a substrate having a complex structure.
In addition, when a thin film is formed, process byproducts are more effectively reduced, corrosion or degradation is prevented, and crystallinity of the thin film is improved, thereby improving electrical characteristics of the thin film.
In addition, when forming a thin film, the step coverage and the thin film density can be improved by reducing process by-products, and further, there is an effect of providing a thin film forming method using the film quality improver and a semiconductor substrate manufactured thereby.
Drawings
Fig. 1 is a graph comparing the results of example 6 of an experiment in which the film quality improver proposed by the present invention was injected first and then to MoO 2Cl2 with an experiment in which the film quality improver was not used, the left side is a graph showing the results of specific resistance measurement, and the right side is a graph showing the results of deposition rate measurement.
Detailed Description
Hereinafter, the film quality improver for a molybdenum-based thin film, the method for forming a molybdenum-based thin film using the same, and the semiconductor substrate manufactured thereby of the present invention will be described in detail.
The term "shielding" in the present invention means, unless otherwise specifically defined, not only reducing, preventing or blocking the adsorption of molybdenum precursor for forming a molybdenum-based film to a substrate, but also reducing, preventing or blocking the adsorption of process by-products to the substrate.
The present inventors have confirmed that, when a film quality improver shielding a molybdenum precursor for forming a molybdenum-based thin film on a substrate surface loaded in a chamber is used, a relatively thin film is formed by forming a shielding region that does not remain in the molybdenum-based thin film, and at the same time, the growth rate of the formed thin film is adjusted, and even when applied to a substrate of a complex structure, the uniformity of the thin film is ensured, thereby greatly improving step coverage, and in particular, it is possible to deposit a thin film, and even when a halide remaining as a process byproduct and an excessive amount of hydrogen gas are used, the amount of carbon residue that is not easily reduced can be improved. Based on this, the present invention has been completed by conducting an effort to develop a film quality improver for a shielding region.
The film quality improver of the present invention provides a film quality improver for a molybdenum-based film.
As an example, the molybdenum-based film may be provided with at least one compound selected from the group consisting of compounds represented by chemical formulas 2 to 36 as a precursor, and in this case, the effects to be achieved by the present invention can be sufficiently obtained.
[ Chemical formula 2] to [ chemical formula 19]
[ Chemical formula 20] to [ chemical formula 32]
[ Chemical formulas 33] to [ chemical formula 36]
In the above chemical formulas 2 to 36, the line is a bond, the intersection point of the bond and the bond of the other element is carbon, hydrogen in an amount satisfying the valence of the carbon is omitted, R ' and R "are each hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ' may be connected to an adjacent R '.
The molybdenum-based thin film can be applied to a semiconductor device as a commonly used diffusion preventing film and electrode.
The film quality improver is a saturated compound represented by chemical formula 1,
[ Chemical formula 1]
Wherein the a is carbon or silicon, the X is fluorine, chlorine, bromine or iodine, the R 1 and the R 3 are independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine, the R 2 is independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine, iodine or a functional group having the formula BR 4R5R6, the B is carbon or silicon, the R 4, the R 5 and the R 6 are independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine, in which case, when forming a molybdenum-based thin film, a relatively sparse thin film is formed by forming a shielding region which does not remain in the molybdenum-based thin film, while suppressing side reactions and adjusting the growth rate of the thin film, reducing process byproducts in the thin film to reduce corrosion or degradation, improving the crystallinity of the thin film, and greatly improving the step coverage and thickness uniformity of the thin film even when forming the thin film on a substrate having a complex structure.
In the chemical formula 1, the a is carbon or silicon, preferably carbon.
Each of R 1、R2 and R 3 is independently an alkyl group having 1 to 3 carbon atoms, at least one of which has 2 or 3 carbon atoms. As a preferable example, any one of R 1、R2 and R 3 has 1 carbon atom, the remaining two have 2 or 3 carbon atoms, and more preferably any one of R 1、R2 and R 3 has 1 carbon atom and the remaining two have 2 carbon atoms, and within this range, the effect of reducing the process by-products is large, the step coverage is excellent, and the film density improving effect and the electric characteristics of the film are more excellent.
In the chemical formula 1, X is a halogen element, preferably fluorine, chlorine or bromine, more preferably chlorine or bromine, and within this range, the effect of reducing process by-products and improving step coverage is more excellent. In addition, as an example, X may be fluorine, and in this case, a process requiring high temperature deposition is more suitable.
As another preferable example, in the chemical formula 1, X may be iodine, within which the crystallinity of the thin film is improved and side reactions are suppressed, so that the effect of reducing process by-products is more excellent.
The compound represented by the above chemical formula 1 is a tertiary alkyl compound substituted with halogen, and as a specific example, is selected from the group consisting of 2-chloro-2-methylpropane, 2-chloro-2-methylbutane, 2-chloro-2-methylpentane, 3-chloro-3-methylhexane, 3-chloro-3-ethylheptane, 3-chloro-3-ethylhexane, 4-chloro-4-methylheptane, 4-chloro-4-ethylheptane, 4-chloro-4-propylheptane, 2-bromo-2-methylpropane, 2-bromo-2-methylbutane, 2-bromo-2-methylpentane, 3-bromo-3-methylhexane, 3-bromo-3-ethylpentane, 3-bromo-3-ethylhexane, 4-bromo-4-methylheptane, 4-bromo-4-ethylheptane, 4-bromo-4-propylheptane, 2-iodo-2-methylpropane, 2-iodo-2-methylpentane, 3-iodo-3-methylethane, 3-bromo-3-ethylpentane, 3-iodo-ethyl-3-ethyl-hexane, 4-iodo-ethyl-3-ethylheptane, 4-iodo-ethyl-heptane, at least one selected from 4-iodo-4-ethylheptane, 4-iodo-4-propylheptane, 2-fluoro-2-methylpropane, 2-fluoro-2-methylbutane, 3-fluoro-3-methylpentane, 3-fluoro-3-methylhexane, 3-fluoro-3-ethylpentane, 3-fluoro-3-ethylhexane, 4-fluoro-4-methylheptane, 4-fluoro-4-ethylheptane, 4-fluoro-4-propylheptane, preferably at least one selected from 2-chloro-2-methylpropane, 2-chloro-2-methylbutane, 3-chloro-3-methylpentane, 2-bromo-2-methylpropane, 2-bromo-2-methylbutane, 3-bromo-3-methylpentane, 2-iodo-2-methylpropane, 2-iodo-2-methylbutane, 3-iodo-3-methylpentane, 2-fluoro-2-methylpropane and 3-fluoro-3-methylpentane, provides a remarkably improved effect of the step coverage by the film growth with a barrier region, a remarkably improved effect of the film growth by the film and a remarkably improved effect of the film growth by the barrier region.
As an example, the compound represented by the chemical formula 1 may be a saturated compound as follows: the refractive index (a) is in the range of 1.38 to 1.72, and the value (b/a) obtained by dividing the vapor pressure (mmHg, b) measured at 25 ℃ by the refractive index (a) is in the range of 0.003 to 0.043. In this case, a shielding region for a molybdenum-based thin film is formed on a substrate to reduce a deposition rate of the molybdenum-based thin film and control a film growth rate, thereby greatly improving step coverage and thickness uniformity of the thin film, and preventing not only film precursor adsorption but also process byproduct adsorption even when the thin film is formed on a substrate having a complicated structure, thereby effectively protecting the surface of the substrate and effectively removing the process byproduct.
In the present invention, the refractive index may be measured by a method known in the art unless otherwise specifically defined. As a specific example, measurements can be made at 25℃using an Abbe (Abbe) refractometer according to ASTM D542.
As a specific example, the compound represented by the chemical formula 1 may be a saturated compound having a refractive index (a) in a range of 1.385 to 1.72 and a value (b/a) obtained by dividing a vapor pressure (mmHg, b) measured at 25 ℃ by the refractive index (a) in a range of 0.032 to 0.043, preferably, a saturated compound having a refractive index (a) in a range of 1.388 to 1.719 and a value (b/a) obtained by dividing a vapor pressure (mmHg, b) measured at 25 ℃ by the refractive index (a) in a range of 0.0035 to 0.043, in which case a shielding region for a molybdenum-based thin film is formed on a substrate to reduce a deposition rate of the molybdenum-based thin film, control a thin film growth rate, thereby greatly improving a step coverage and thickness uniformity of the thin film even when a thin film is formed on a substrate having a complex structure, and preventing not only the adsorption of a thin film precursor but also the adsorption of a process by-product, thereby effectively protecting the surface of the substrate and removing the by-product of the process.
Regarding the reactivity of the film quality improver with the molybdenum precursor, when the integral value of the H-NMR spectrum measured before mixing the film quality improver and the molybdenum precursor and the H-NMR spectrum measured by pressurizing the mixture at a 1:1 molar ratio for 1 hour is set as the impurity content, the impurity content (%) is shown to be less than 0.1%, so that when the film quality improver is used, the process by-product can be reduced while not interfering with the adsorption of the molybdenum precursor, and the deposition rate can be adjusted to control the film growth rate, so that the step coverage and film quality can be improved, corrosion or degradation is prevented, and the crystallinity of the film is improved, even when the film is formed on a substrate having a complex structure, so that the specific resistance characteristics and electrical characteristics of the film can be improved.
Due to the above reactivity, the film quality improver has an advantage in that the viscosity or vapor pressure of the molybdenum precursor can be easily adjusted without impeding the behavior of the molybdenum precursor.
As an example, the film quality improver exhibiting such reactivity may be a linear or branched paraffin compound or a naphthene compound substituted with halogen.
As a specific example, at least one selected from the group consisting of 1-iodobutane, 2-iodo-3-methylbutane, 3-iodo-2, 4-dimethylpentane, cyclohexyliodine, cyclopentylidine, 1-bromobutane, 2-bromo-3-methylbutane, 3-bromo-2, 4-dimethylpentane, cyclohexylbromine and cyclopentylbromine, preferably at least one selected from the group consisting of 1-iodobutane and 2-iodobutane, is used, and at this time, the film quality improver effectively protects the surface of the substrate while not interfering with the adsorption of the molybdenum precursor, and effectively removes process by-products.
The film quality improver does not remain in the molybdenum-based film.
At this time, unless otherwise defined, no residue means that, when the component is analyzed by XPS, the C element content 1.0 atom%, the Si element content less than 1.0 atom%, the N element content less than 1.0 atom%, and the halogen content less than 1.0 atom% are present.
The molybdenum-based thin film may be used as a diffusion preventing film (diffusion barrier) or an electrode (electrode), and is not limited thereto.
Preferably, the film quality improver may be a compound having a purity of 99.9% or more, a compound having a purity of 99.95% or more, or a compound having a purity of 99.99% or more, and when a compound having a purity of less than 99% is used as a reference, impurities may be formed, and therefore, it is preferable to use 99% or more as much as possible.
Preferably, the compound represented by the chemical formula 1 is used for an Atomic Layer Deposition (ALD) process, in which case, the surface of the substrate is effectively protected as a film quality improver while not interfering with adsorption of a molybdenum precursor, and process byproducts are effectively removed.
Preferably, the compound represented by the chemical formula 1 is a liquid at normal temperature (22 ℃) and may have a density of 0.8 to 2.5g/cm 3 or 0.8 to 1.5g/cm 3, a vapor pressure (20 ℃) may be 0.1 to 300mmHg or 1 to 300mmHg, a solubility in water (25 ℃) may be 200mg/L or less, a shielding region may be effectively formed in this range, and excellent effects on step coverage, thickness uniformity of a thin film, and improvement of film quality may be achieved.
More preferably, the compound represented by the chemical formula 1 may have a density of 0.75 to 2.0g/cm 3 or 0.8 to 1.3g/cm 3, a vapor pressure (20 ℃) of 1 to 260mmHg, and a solubility in water (25 ℃) of 160mg/L or less, in which a shielding region is effectively formed, and has excellent effects on step coverage, thickness uniformity of a thin film, and improvement of film quality.
The molybdenum-based thin film forming method of the present invention includes a step of injecting a film quality improver represented by the following chemical formula 1 into an ALD chamber and adsorbing it to a surface of a loaded (loaded) substrate,
[ Chemical formula 1]
Wherein a is carbon or silicon, X is fluorine, chlorine, bromine or iodine, R 1 and R 3 are independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine, R 2 is independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine, iodine or a functional group having the formula BR 4R5R6, B is carbon or silicon, R 4, R 5 and R 6 are independently hydrogen, alkyl having 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine, in which case a shielding region for a molybdenum-based thin film is formed on a substrate to reduce the deposition rate of the molybdenum-based thin film, control the growth rate of the thin film, thereby greatly improving the step coverage and the thickness uniformity of the thin film even when the thin film is formed on a substrate having a complicated structure, and providing a film quality improving effect such as improvement of specific resistance.
In the step of shielding the substrate surface with the film quality improver, the supply time (FEEDING TIME) of the film quality improver per cycle relative to the substrate surface is preferably 0.01 to 5 seconds, more preferably 0.02 to 3 seconds, still more preferably 0.04 to 2 seconds, still more preferably 0.05 to 1 second, within which the film growth rate is low and the step coverage and economy are excellent.
In the present invention, the supply time of the membrane quality improver is based on the volume 15 to 20L of the chamber and the flow rate 0.5 to 5mg/s, more specifically, based on the volume 18L of the chamber and the flow rate 1 to 2 mg/s.
As an embodiment, the thin film forming method may include: step i-a: vaporizing the film quality improver to shield a surface of a substrate loaded into an ALD chamber; step ii-a: purging the interior of the chamber with a purge gas for a first time; step iii-a: vaporizing and adsorbing a molybdenum precursor to a surface of a substrate loaded in a chamber; step iv-a: purging the interior of the chamber a second time with a purge gas; step v-a: supplying a reaction gas into the chamber; step vi-a: and purging the interior of the chamber with a purge gas a third time. At this time, the steps i-a to vi-a are taken as a unit cycle (cycle), and the cycle can be repeated in order to form a thin film having a desired thickness. Thus, when the film quality improver of the present invention is put into and adsorbed to the substrate before the molybdenum precursor per cycle, the film growth rate can be properly reduced even when deposition is performed at a high temperature, and the generated process by-products can be effectively removed, so that the specific resistance of the film can be reduced and the step coverage can be greatly improved.
As a preferred further embodiment, the thin film forming method may include: step i-b: vaporizing and adsorbing a molybdenum precursor to a surface of a substrate loaded in a chamber; step ii-b: purging the interior of the chamber with a purge gas for a first time; step iii-b: vaporizing and adsorbing the film quality improver to the surface of a substrate loaded in a chamber; step iv-b: purging the interior of the chamber a second time with a purge gas; step v-b: supplying a reaction gas into the chamber; step vi-b: and purging the interior of the chamber with a purge gas a third time. At this time, the steps i-b to vi-b are taken as a unit cycle, and the cycle can be repeated in order to form a thin film having a desired thickness. In this way, when the film quality improver of the present invention is put into and adsorbed to the substrate at a later time per cycle than the molybdenum precursor, the film quality improver can be used as a growth activator for film formation, in which case the film growth rate is increased and the density and crystallinity of the film are increased, thereby reducing the specific resistance of the film and greatly improving the electrical characteristics.
As a preferred example, in the film formation method of the present invention, the film quality improver of the present invention can be put into and adsorbed onto the substrate before the molybdenum precursor in one cycle, and at this time, the film growth rate can be reduced appropriately even when the film is deposited at a high temperature, thereby greatly reducing the process by-products and greatly improving the step coverage, increasing the crystallinity of the film to reduce the specific resistance of the film, and greatly improving the uniformity of the film thickness even when applied to a semiconductor device having a large aspect ratio, to ensure the reliability of the semiconductor device.
As an example, in the film formation method, when the film quality improver is deposited before or after the deposition of the molybdenum precursor, 1 to 99,999 times of unit cycles, preferably 10 to 10,000 times of unit cycles, more preferably 50 to 5,000 times of unit cycles, and further preferably 100 to 2,000 times of unit cycles may be repeated as needed, and within this range, the effect to be achieved by the present invention may be sufficiently obtained while obtaining a film having a desired thickness.
In one example, the chamber may be an ALD chamber or a CVD chamber.
In the present invention, a step of vaporizing and injecting the film quality improver or molybdenum precursor and then performing a plasma post-treatment may be included, in which case, the process by-product can be reduced while improving the growth rate of the thin film.
When the molybdenum precursor is adsorbed on the substrate before the molybdenum precursor is adsorbed thereon, or when the molybdenum precursor is adsorbed on the substrate before the molybdenum precursor is adsorbed thereon, the amount of the purge gas injected into the chamber in the step of purging the non-adsorbed film quality improver is not particularly limited as long as the non-adsorbed film quality improver can be sufficiently removed, and may be, for example, 10 to 100,000 times, preferably 50 to 50,000 times, more preferably 100 to 10,000 times, within which range the non-adsorbed film quality improver is sufficiently removed, thereby enabling uniform formation of a thin film and preventing degradation of the film quality. Wherein the injection amounts of the purge gas and the film quality improver are respectively based on one period, and the volume of the film quality improver refers to the volume of vaporized film quality improver steam.
As a specific example, the membrane conditioner was injected (every cycle) at a flow rate of 1.66mL/s and an injection time of 0.5sec, and when the purge gas was injected (every cycle) at a flow rate of 166.6mL/s and an injection time of 3sec in the step of purging the non-adsorbed membrane conditioner, the injection amount of the purge gas was 602 times the injection amount of the membrane conditioner.
In the step of purging the non-adsorbed molybdenum precursor, the amount of the purge gas injected into the ALD chamber is not particularly limited as long as the non-adsorbed molybdenum precursor can be sufficiently removed, and may be, for example, 10 to 10,000 times, preferably 50 to 50,000 times, more preferably 100 to 10,000 times, the volume of the molybdenum precursor injected into the ALD chamber, and within this range, the non-adsorbed molybdenum precursor is sufficiently removed, thereby enabling uniform formation of a thin film and preventing deterioration of film quality. Wherein, the injection amounts of the purge gas and the molybdenum precursor are respectively based on a period, and the volume of the molybdenum precursor refers to the volume of the vaporized molybdenum precursor steam.
In addition, in the purge step performed immediately after the step of supplying the reaction gas, as an example, the amount of the purge gas injected into the ALD chamber may be 10 to 10,000 times, preferably 50 to 50,000 times, more preferably 100 to 10,000 times, the volume of the reaction gas injected into the ALD chamber, and in this range, a desired effect may be sufficiently obtained. Wherein the injection amounts of the purge gas and the reaction gas are respectively based on one cycle.
Preferably, the film quality improver and molybdenum precursor may be transferred into the ALD chamber by a vapor phase flow control (VFC), direct Liquid Injection (DLI), or liquid transfer system (LDS), more preferably, by an LDS.
As an example, the substrate loaded in the chamber may be heated to 50 to 700 ℃, and as a specific example, may be heated to 300 to 700 ℃, and the film quality improver or the molybdenum precursor may be injected onto the substrate in an unheated or heated state, and the heating condition may be adjusted during the deposition process after the injection in an unheated state according to the deposition efficiency. As an example, the substrate may be implanted at 50 to 700 ℃ for 1 to 20 seconds.
The ratio of the film quality improver to the injection amount (mg/cycle) in the chamber of the molybdenum precursor may preferably be 1:1.5 to 1:20, more preferably may be 1:2 to 1:15, more preferably may be 1:2 to 1:12, further preferably may be 1:2.5 to 1:10, within which the step coverage improving effect and the process byproduct reducing effect are good.
As an example, in the present invention, the molybdenum precursor and the nonpolar solvent are mixed and put into a chamber, and at this time, the viscosity or vapor pressure of the molybdenum precursor can be easily adjusted.
Preferably, the nonpolar solvent may be at least one selected from alkanes and cycloalkanes, and in this case, an organic solvent having low reactivity and solubility and being easy to manage moisture is contained, and step coverage can be improved even if deposition temperature is increased when forming a thin film.
As a more preferred example, the nonpolar solvent may contain C1-C10 alkane (alkine) or C3-C10 cycloalkane (cycloalkane), preferably C3-C10 cycloalkane, in which case the reactivity and solubility are low and the water is easy to manage.
In the present invention, C1, C3, etc. represent the number of carbon atoms.
Preferably, the cycloalkane may be a C3-C10 monocycloalkane, and cyclopentane (cyclopentane) in the monocycloalkane is liquid at normal temperature and has the highest vapor pressure, so that it is preferable in a vapor deposition process, but not limited thereto.
As an example, the solubility of the nonpolar solvent in water (25 ℃) is 200mg/L or less, preferably 50 to 400mg/L, more preferably 135 to 175mg/L, within which the reactivity to molybdenum precursor is low and the moisture management is easy.
In the present invention, the solubility is not particularly limited based on a measurement method or standard commonly used in the art to which the present invention pertains, and as an example, a saturated solution can be measured by an HPLC method.
Preferably, the content of the nonpolar solvent may be 5 to 95 wt%, more preferably 10 to 90 wt%, more preferably 40 to 90 wt%, and most preferably 70 to 90 wt%, relative to the total weight of the molybdenum precursor and nonpolar solution.
When the content of the nonpolar solvent to be charged is greater than the upper limit value, impurities are induced to increase the resistance and the value of impurities in the thin film, and when the content of the organic solvent to be charged is less than the lower limit value, there are disadvantages in that the effect of improving step coverage by adding a solvent and the effect of reducing impurities such as chlorine (Cl) ions are low.
As an example, in the molybdenum-based thin film forming method, when the film quality improver is used, the film growth rate per cycle (angstrom/period) calculated by the following equation 1) The reduction ratio of (2) is-5% or less, preferably-10% or less, more preferably-20% or less, more preferably-30% or less, further preferably-40% or less, most preferably-45% or less, within which the step coverage and the film thickness uniformity are excellent.
[ Mathematics 1]
Reduction rate of film growth rate per cycle (%) = [ (film growth rate per cycle when film quality improver was used-film growth rate per cycle when film quality improver was not used)/film growth rate per cycle when film quality improver was not used ] ×100.
In the above expression 1, the film growth rate per cycle when the film quality improver is used and not used means the film deposition thickness per cycle (angstrom/cycle), that is, the deposition rate, which is calculated by dividing the total cycle number by the final thickness of the film measured by an ellipsometer (Ellipsometery), as an example.
In the above expression 1, the term "when the film quality improver is not used" refers to a case where a film is produced by adsorbing only a molybdenum precursor on a substrate in a film deposition process, and specifically refers to a case where a film is formed by omitting a step of adsorbing the film quality improver and a step of purging the film quality improver that is not adsorbed in the film formation method.
In the molybdenum-based film forming method, the method is based on SIMS measurementThe residual halogen strength (c/s) in the film based on the film thickness may be preferably 100,000 or less, more preferably 70,000 or less, still more preferably 50,000 or less, still more preferably 10,000 or less, and may be 5,000 or less, more preferably 1,000 to 4,000, still more preferably 1,000 to 3,800, in this range, excellent corrosion and deterioration preventing effects are exhibited.
In the present invention, the purge is preferably 1,000 to 50,000sccm (Standard Cubic centimeter CENTIMETER PER min), more preferably 2,000 to 30,000sccm, still more preferably 2,500 to 15,000sccm, within which the film growth rate per cycle is appropriately controlled, and a monolayer atomic layer (atomic mono-layer) or an approximately monolayer atomic layer is deposited, so that it is advantageous in terms of film quality.
The atomic layer deposition process is very advantageous in the fabrication of integrated circuits (INTEGRATED CIRCUIT; ICs) requiring high aspect ratios, and in particular, has advantages such as excellent step coatability (conformality (conformality)), uniform coverage (uniformity), and precise thickness control through a self-limiting thin film growth mechanism.
As an example, the thin film forming method may be performed at a deposition temperature ranging from 50 to 800 ℃, preferably from 300 to 700 ℃, more preferably from 350 to 650 ℃, in which an Atomic Layer Deposition (ALD) process characteristic is achieved while growing a thin film of excellent film quality.
As an example, the thin film formation method may be performed at a deposition pressure in the range of 0.01 to 30Torr, preferably 0.1 to 30Torr, more preferably 1 to 30Torr, and even more preferably 5 to 20Torr, in which a thin film of uniform thickness is obtained.
In the present invention, the deposition temperature and deposition pressure are measured by the temperature and pressure formed in the deposition chamber, and also by the temperature and pressure applied to the substrate in the deposition chamber.
Preferably, the molybdenum-based thin film manufacturing method may include the steps of: heating the temperature in the chamber to a deposition temperature prior to the film quality improver being introduced into the chamber; and/or injecting an inert gas into the chamber for purging prior to the pouring of the membrane conditioner into the chamber.
The present invention also relates to a thin film manufacturing apparatus capable of realizing the thin film manufacturing method, comprising: an atomic layer deposition chamber; a first vaporizer for vaporizing the film quality improver; a first transfer unit transferring the vaporized film quality improver into the atomic layer deposition chamber; a second vaporizer for vaporizing the film precursor; and a second transfer unit transferring the vaporized thin film precursor into the atomic layer deposition chamber. Among them, when the vaporizer and the transfer unit are those commonly used in the art to which the present invention pertains, there is no particular limitation.
As a specific example, the film formation method will be described. First, a substrate on which a thin film is to be formed is placed in a deposition chamber capable of atomic layer deposition.
The substrate may include a silicon substrate, a silicon oxide, or the like semiconductor substrate.
The substrate may be further formed with a conductive layer or an insulating layer at an upper portion thereof.
For depositing a thin film on a substrate located in the deposition chamber, the above-mentioned film quality improver and a molybdenum precursor or a mixture of the molybdenum precursor and a nonpolar solvent are prepared, respectively.
Then, the prepared film quality improver is injected into the vaporizer, then converted into a vapor phase, transferred to the deposition chamber, adsorbed on the substrate, and purged to remove the film quality improver not adsorbed.
Then, after the prepared molybdenum precursor or a mixture of the molybdenum precursor and a nonpolar solvent (composition for forming a thin film) is injected into the vaporizer, it is changed into a vapor phase, transferred to the deposition chamber and adsorbed on the substrate, and the molybdenum precursor/composition for forming a thin film that is not adsorbed is purged.
In the invention, the following process sequence can be replaced according to the need: after adsorbing the film quality improver on a substrate, purging to remove the film quality improver which is not adsorbed; and adsorbing the molybdenum precursor on the substrate and purging to remove the non-adsorbed molybdenum precursor.
As an example, in the present invention, the film quality improver, the molybdenum precursor (composition for forming a thin film), and the like may be transferred to the deposition chamber by a gas phase flow control (Vapor Flow Control; VFC) method for transferring a volatile gas by a mass flow control (Mass Flow Controller; MFC) method or a Liquid transfer system (Liquid DELIVERY SYSTEM; LDS) method for transferring a Liquid by a Liquid mass flow control (Liquid Mass Flow Controller; LMFC) method, and an LDS method is preferable.
In this case, as a carrier gas or a diluent gas for moving the film quality improver, the molybdenum precursor, and the like onto the substrate, one or a mixture gas of two or more selected from argon (Ar), nitrogen (N 2), and helium (He) may be used, but is not limited thereto.
As an example, in the present invention, the purge gas may be an inert gas, and the carrier gas or the diluent gas may be preferably used.
Then, the reaction gas is supplied. When the reaction gas is a reaction gas commonly used in the art to which the present invention pertains, there is no particular limitation, and preferably, a reducing agent, a nitriding agent, or an oxidizing agent may be included. The nitriding agent reacts with the molybdenum precursor adsorbed to the substrate to form a nitride film, the reducing agent reacts with the molybdenum precursor adsorbed to the substrate to form a metal film, and the oxidizing agent reacts with the molybdenum precursor adsorbed to the substrate to form an oxide film.
Preferably, the nitriding agent may be nitrogen (N 2), hydrazine gas (N2H 4) or a mixture of nitrogen and hydrogen, the oxidizing agent may be oxygen (O 2), ozone or a mixture of oxygen and ozone, and the reducing agent may be hydrogen (H 2) or the like.
In the thin film forming method, as an example, the deposition temperature may be 50 to 800 ℃, preferably 200 to 700 ℃, and as a specific example, 250 to 500 ℃, 250 to 450 ℃, 380 to 420 ℃, or 400 to 450 ℃, within which the specific resistance of the thin film, the step coverage, etc. are greatly improved.
Then, the residual reaction gas which does not participate in the reaction is purged with an inert gas. Thus, not only the excess reaction gas but also the by-products generated can be removed at the same time.
As described above, in the molybdenum-based thin film forming method, as an example, the step of shielding the substrate with the film quality improver, the step of purging the non-adsorbed film quality improver, the step of adsorbing the molybdenum precursor/thin film forming composition on the substrate, the step of purging the non-adsorbed molybdenum precursor/thin film forming composition, the step of supplying the reaction gas, and the step of purging the remaining reaction gas are used as unit periods, and the unit periods may be repeated to form a thin film having a desired thickness.
As another example, in the molybdenum-based thin film forming method, the step of adsorbing the molybdenum precursor/thin film forming composition on the substrate, the step of purging the non-adsorbed molybdenum precursor/thin film forming composition, the step of adsorbing the film quality improver on the substrate, the step of purging the non-adsorbed film quality improver, the step of supplying the reaction gas, and the step of purging the remaining reaction gas are taken as a unit period, and the unit period may be repeated in order to form a thin film having a desired thickness.
As an example, the unit cycle may be repeatedly performed 1 to 99,999 times, preferably 10 to 1,000 times, more preferably 50 to 5,000 times, and still more preferably 100 to 2,000 times, within which range the effect of well exhibiting the desired film characteristics is exhibited.
The present invention also provides a semiconductor substrate produced by the molybdenum-based thin film forming method of the present invention, which has the effect that the step coverage of the thin film and the thickness uniformity of the thin film are excellent and the density and electrical characteristics of the thin film are excellent.
Preferably, the thickness of the film produced is 20nm or less, the specific resistance value is 0.1 to 400 μΩ·cm, the halogen content is 10,000ppm or less, the step coverage is 90% or more based on the film thickness of 10nm, within this range, the performance as a diffusion preventing film is excellent, and the effect of reducing corrosion of the metal wiring material is exhibited, but is not limited thereto.
As an example, the thickness of the thin film may be 1 to 20nm, preferably 3 to 25nm, more preferably 5 to 20nm, within which the thin film characteristics are excellent.
As an example, the specific resistance value of the film may be 0.1 to 400 μΩ·cm, preferably 15 to 300 μΩ·cm, more preferably 20 to 290 μΩ·cm, still more preferably 25 to 280 μΩ·cm, based on a film thickness of 10nm, and within this range, the film characteristics are excellent.
Preferably, in the film, the halogen content may be 10,000ppm or less or1 to 9,000ppm, more preferably 5 to 8,500ppm, still more preferably 100 to 1,000ppm, within which range, while the film characteristics are excellent, has an effect of reducing the film growth rate. Among these, as an example, the halogen remaining in the thin film may be Cl 2, cl or Cl -, and the lower the amount of halogen remaining in the thin film, the more excellent the film quality.
As an example, the step coverage of the thin film is 90% or more, preferably 92% or more, and more preferably 95% or more, and in this range, even a thin film having a complicated structure is easily deposited on a substrate, and thus can be applied to a new-generation semiconductor device.
Unless specifically defined otherwise, the step coverage of the present invention can be calculated by a manner well known in the art, for example, measuring the thickness of a thin film deposited at the upper end portion (upper deposition thickness) and the thickness of a thin film deposited at the side face portion (side deposition thickness), and dividing the upper deposition thickness by the side deposition thickness to obtain a value expressed as a percentage.
As an example, the specific resistance value of the thin film is 1500 μΩ·cm or less, preferably 1400 μΩ·cm or less, more preferably 1300 μΩ·cm or less, and in this range, it is possible to provide the electrical characteristics required for the thin film having a complicated structure, and the thin film can be applied to the next-generation semiconductor device.
As an example, the thin film may be manufactured to include a molybdenum film, a molybdenum oxide film, or a molybdenum nitride film, in which case it is effectively used as an anti-diffusion film or an electrode of a semiconductor device.
As an example, the film may have a multilayer structure of two or three layers, as required. As a specific example, the multilayer film of the two-layer structure may be a lower layer film-middle layer film structure. As a specific example, the three-layer structured multilayer film may be a lower layer film-middle layer film-upper layer film structure.
As an example, the lower film may include at least one selected from the group consisting of Si、SiO2、MgO、Al2O3、CaO、ZrSiO4、ZrO2、HfSiO4、Y2O3、HfO2、LaLuO2、Si3N4、SrO、La2O3、Ta2O5、BaO、TiO2.
As an example, the middle layer may comprise Ti xNy, preferably TN.
As an example, the upper layer film may include at least one selected from W and Mo.
Hereinafter, preferred embodiments and drawings are presented to aid understanding of the present invention, however, it will be apparent to those skilled in the art that the following embodiments and drawings are merely illustrative of the present invention and various changes and modifications can be made within the scope and technical spirit of the present invention, and such changes and modifications are definitely within the scope of the appended claims.
Examples
Examples 1 to 5, comparative examples 1 to 3, reference example 1
As the film quality improver and molybdenum precursor to be used in the experiment, the combinations shown in table 1 below were selected.
TABLE 1
Example 1
Of the compounds described in table 1, tert-butyl iodide (tert-butyl iodide) as a film quality improver and a compound MoO 2Cl2 represented by chemical formula 34 as a molybdenum precursor were prepared, respectively. The prepared film quality improver and film precursor compound were placed in respective cans, and supplied to a vaporizer heated to 150℃at a flow rate of 0.05g/min by a liquid mass flow controller at ordinary temperature.
After the film quality improver vaporized into a vapor phase in the vaporizer and the thin film precursor compound were injected into the deposition chamber loaded with the Si substrate at a ratio of injection amount of 1:1 for 1 second, argon gas was supplied at 5000sccm for 2 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.
Then, after ammonia gas was injected as a reaction gas into the reaction chamber at 1000sccm for 3 seconds, argon purging was performed for 3 seconds. At this time, the substrates to be formed with the metal thin films were heated to 380 ℃ respectively, which is the temperature shown in table 2 below. This process was repeated 200 to 400 times to form a MoN film as a self-limiting atomic layer having a thickness of 10 nm.
Example 2
Of the compounds described in table 1, tert-butyl iodide as a film quality improver and MoO 2Cl2 as a molybdenum precursor, which is a compound represented by chemical formula 34, were prepared, respectively. The prepared film quality improver and film precursor compound were placed in respective cans, and supplied to a vaporizer heated to 150℃at a flow rate of 0.05g/min by a liquid mass flow controller at ordinary temperature.
After the film quality improver vaporized into a vapor phase in the vaporizer and the thin film precursor compound were injected into the deposition chamber loaded with the Si substrate at a ratio of injection amount of 1:1 for 1 second, argon gas was supplied at 5000sccm for 2 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.
Then, after ammonia gas was injected as a reaction gas into the reaction chamber at 1000sccm for 3 seconds, argon purging was performed for 3 seconds. At this time, the substrates to be formed with the metal thin films were heated to 400 ℃ respectively, which is the temperature shown in table 2 below. This process was repeated 200 to 400 times to form a MoN film as a self-limiting atomic layer having a thickness of 10 nm.
Example 3
Of the compounds described in table 1, tert-butyl iodide as a film quality improver and MoO 2Cl2 as a molybdenum precursor, which is a compound represented by chemical formula 34, were prepared, respectively. The prepared film quality improver and film precursor compound were placed in respective cans, and supplied to a vaporizer heated to 150℃at a flow rate of 0.05g/min by a liquid mass flow controller at ordinary temperature.
After the film quality improver vaporized into a vapor phase in the vaporizer and the thin film precursor compound were injected into the deposition chamber loaded with the Si substrate at a ratio of injection amount of 1:1 for 1 second, argon gas was supplied at 5000sccm for 2 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5Torr.
Then, after ammonia gas was injected as a reaction gas into the reaction chamber at 1000sccm for 3 seconds, argon purging was performed for 3 seconds. At this time, the substrates to be formed with the metal thin films were heated to the temperatures shown in table 2 below at 420 ℃. This process was repeated 200 to 400 times to form a MoN film as a self-limiting atomic layer having a thickness of 10 nm.
Comparative examples 1 to 3
The same process as in examples 1 to 3 was repeated except that no film quality improver was contained in examples 1 to 3.
As a result, a MoN thin film having a thickness of 10nm as a self-limiting atomic layer was formed.
Example 4
The same procedure as in example 1 was repeated except that in example 1, the film quality improver vaporized into a vapor phase in the vaporizer and the thin film precursor compound were sequentially injected into the deposition chamber on which the substrate was mounted in a ratio of 1:1 for 1 second, and then argon was supplied at 5000sccm for 2 seconds to perform argon purging.
Specifically, after injecting the film quality improver vaporized into the vapor phase in the vaporizer into the deposition chamber loaded with the substrate for 1 second, argon gas was supplied at 5000sccm for 2 seconds to perform argon purging, and after injecting the molybdenum precursor vaporized into the vapor phase in the vaporizer into the deposition chamber loaded with the substrate for 1 second, argon gas was supplied at 5000sccm for 2 seconds to perform argon purging.
As a result, the process was repeated 200 to 400 times, thereby forming a MoN thin film having a thickness of 10nm as a self-limiting atomic layer.
Example 5
The same process as in example 1 was repeated except that in example 1, the film precursor and the film quality improver vaporized into vapor phase in the vaporizer were sequentially injected into the deposition chamber on which the substrate was mounted in a ratio of 1:1 for 1 second, and then argon was supplied at 5000sccm for 2 seconds to perform argon purging.
Specifically, after injecting the molybdenum precursor vaporized into the vapor phase in the vaporizer into the deposition chamber loaded with the substrate for 1 second, argon gas was supplied at 5000sccm for 2 seconds to perform argon purging, and after injecting the film quality improver vaporized into the vapor phase in the vaporizer into the deposition chamber loaded with the substrate for 1 second, argon gas was supplied at 5000sccm for 2 seconds to perform argon purging.
As a result, the process was repeated 200 to 400 times, thereby forming a MoN thin film having a thickness of 10nm as a self-limiting atomic layer.
Reference example 1
The same process as in example 1 was repeated except that in example 1, iodobutane (iodobutane) was used as a film quality improver instead of t-butyl iodide.
As a result, a MoN thin film having a thickness of 10nm as a self-limiting atomic layer was formed.
Experimental example
1) Deposition evaluation (deposition rate per cycle, GPC)
For the produced film, the thickness of the film deposited per cycle was calculated by dividing the film thickness measured by an Ellipsometer (ellisometer), which is an apparatus for measuring optical characteristics such as the thickness or refractive index of the film using the polarization characteristics of light, by the number of cycles, to evaluate the deposition rate, and the result is shown in table 2 below.
2) Film resistance evaluation (specific resistance)
After measuring the surface resistance of the produced film by a four-point probe method, the specific resistance value (. Mu.. OMEGA.. Multidot.cm) was calculated from the thickness value of the film, and the results are shown in Table 2 below.
TABLE 2
As shown in table 2 above, when the tert-butyl iodide of the present invention was used as a film quality improver together with a film precursor compound (examples 1 to 3), the same or similar deposition rate was provided as that when the film quality improver was not used (comparative examples 1 to 3), and at the same time, since the specific resistance was shown to be reduced to 919 to 1884 μΩ·cm, it was confirmed that the film growth rate was properly controlled, thereby improving the electrical characteristics.
3) Impurity reduction characteristics
In order to compare the reduction characteristics of the impurities, i.e., the process byproducts, of the thin film having a thickness of 10nm, X-ray photoelectron spectroscopy (X-ray Photoelectron Spectroscopy; XPS) analysis was performed on titanium (Ti), nitrogen (N), chlorine (Cl), carbon (C) and oxygen (O) elements, and the results are shown in Table 3 below.
TABLE 3
As shown in table 3, when the film quality improver of the present invention was used together with the film precursor compound (example 1), the film quality improver showed the same or similar level as that when the film quality improver was not used (comparative example 1), and the strength of Cl and C was reduced to 0.01% level as compared with that when the film quality improver was used (reference example 1), so that it was confirmed that the impurity reduction characteristics were excellent. In particular, in the case of comparative example 1, since the film quality improver was not added, carbon should not be detected theoretically, but it was confirmed that carbon suspected to be contained in trace amounts of CO and/or CO 2 contained in the film precursor compound, the purge gas, and the reaction gas was detected, whereas in example 1 of the present invention, although the film quality improver as a hydrocarbon was added at the time of film deposition, it was confirmed that the carbon strength was reduced compared with comparative example 1, which means that the impurity reduction characteristics of the film quality improver of the present invention were excellent.
In particular, similar to the film quality improver of the present invention, the halide compound was added in reference example 1, but the impurity intensity was too high compared with example 1 and comparative example 1, and therefore it was confirmed that the film quality improving effect was not exhibited.
Further, in order to confirm the effect of the film quality improver in the different injection steps, the following experiment was further performed.
Example 6
Atomic layer deposition evaluation was performed using MoO 2Cl2 as Mo precursor and VFC supply.
The pot heating temperature of MoO 2Cl2 was 90℃and the deposition evaluation temperatures were 380℃and 400℃and 420℃respectively. The process pressure was 6torr and the flow rates of the ammonia reactive gas and the Ar purge gas were 1000sccm.
A MoN film was deposited and compared to confirm specific resistance and GPC improvement.
Specifically, after the post-injection experiment and the pre-injection experiment were performed, respectively, the specific resistance and the deposition rate were measured in the method shown in the previous experimental example, and as a control group, the specific resistance and the deposition rate were also measured for the MoN thin film manufactured without the investment of the film quality improver. The post-injection experiment was performed by performing Ar purge after MoO 2Cl2 was injected, injecting tertiary butyl iodide, injecting Ar, injecting NH 3 reaction gas, injecting Ar, and performing an atomic layer deposition experiment, while the post-injection experiment was performed by changing the sequence, injecting tertiary butyl iodide, injecting Ar, injecting MoO 2Cl2, injecting Ar, injecting NH 3 reaction gas, injecting Ar, and performing an atomic layer deposition experiment.
The respective measurement results are shown in fig. 1. FIG. 1 is a graph comparing the results of example 6 of an experiment in which a membrane conditioner proposed by the present invention was injected first and then into MoO 2Cl2 with a control experiment in which no membrane conditioner was used.
As shown in fig. 1, it was confirmed that the specific resistance shown in the left graph was improved in both the first injection and the second injection compared to the control, and that the first injection showed the most improved results and the right graph showed the further improved results in the first injection, respectively, and that the effect of injecting the film quality improver first was better than that of injecting it later.
Claims (13)
1. A film quality improver for molybdenum-based films, characterized in that,
The molybdenum-based film comprises molybdenum metal, molybdenum oxide or molybdenum nitride on a substrate,
The film quality improver is a saturated compound represented by the following chemical formula 1,
[ Chemical formula 1]
In the chemical formula 1, the a is carbon or silicon,
X is fluorine, chlorine, bromine or iodine,
Said R 1 and said R 3 are independently hydrogen, alkyl of 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine,
The R 2 is independently hydrogen, alkyl of 1 to 5 carbon atoms, fluorine, chlorine, bromine, iodine, or a functional group having the formula BR 4R5R6, the B is carbon or silicon, and the R 4, R 5, and R 6 are independently hydrogen, alkyl of 1 to 5 carbon atoms, fluorine, chlorine, bromine, or iodine.
2. The film quality improver for a molybdenum-based film according to claim 1, characterized in that,
The refractive index a of the film quality improver is in the range of 1.38 to 1.72, the value b/a obtained by dividing the vapor pressure b measured at 25 ℃ by the refractive index a is in the range of 0.003 to 0.043,
The unit of the vapor pressure is mmHg.
3. The film quality improver for a molybdenum-based film according to claim 1, characterized in that,
The membranous improver is a compound as follows: the integral value of the peak top of the newly generated peak in the 1 H-NMR spectrum measured after mixing and pressurizing the film quality improver and the molybdenum precursor in a molar ratio of 1:1 is less than 0.1% with respect to the 1 H-NMR spectrum of the film quality improver,
The molybdenum precursor is solid or liquid at 20 ℃ and 1 bar.
4. The film quality improver for a molybdenum-based film according to claim 1, characterized in that,
The film quality improver does not remain in the molybdenum-based film.
5. The film quality improver for a molybdenum-based film according to claim 1, characterized in that,
The molybdenum-based film is used as a diffusion preventing film or electrode.
6. A method for forming a molybdenum-based thin film, comprising the steps of:
injecting a film quality improver of a saturated structure represented by the following chemical formula 1 into a chamber and into a surface of a loaded substrate;
[ chemical formula 1]
In the chemical formula 1, the a is carbon or silicon,
X is fluorine, chlorine, bromine or iodine,
Said R 1 and said R 3 are independently hydrogen, alkyl of 1 to 5 carbon atoms, fluorine, chlorine, bromine or iodine,
The R 2 is independently hydrogen, alkyl of 1 to 5 carbon atoms, fluorine, chlorine, bromine, iodine, or a functional group having the formula BR 4R5R6, the B is carbon or silicon, and the R 4, R 5, and R 6 are independently hydrogen, alkyl of 1 to 5 carbon atoms, fluorine, chlorine, bromine, or iodine.
7. The method for forming a molybdenum-based film according to claim 6, wherein,
The film is an oxide film, a nitride film or a metal film.
8. The method for forming a molybdenum-based film according to claim 6, wherein,
The film quality improver is transferred into a chamber through a gas phase flow control mode, a direct liquid injection mode or a liquid transfer system mode, wherein the chamber is an atomic layer deposition chamber or a chemical vapor deposition chamber.
9. The molybdenum-based film forming method according to claim 6, characterized in that the molybdenum-based film forming method comprises:
step i-a: vaporizing the film quality improver to form a shielded region on a surface of a substrate loaded in a chamber;
step ii-a: purging the interior of the chamber with a purge gas for a first time;
Step iii-a: vaporizing and adsorbing a molybdenum precursor to a region that is free of the shielded region;
Step iv-a: purging the interior of the chamber a second time with a purge gas;
Step v-a: supplying a reaction gas into the chamber; and
Step vi-a: and purging the interior of the chamber with a purge gas a third time.
10. The molybdenum-based film forming method according to claim 6, characterized in that the molybdenum-based film forming method comprises:
step i-b: vaporizing and adsorbing a molybdenum precursor to a surface of a substrate loaded in a chamber;
step ii-b: purging the interior of the chamber with a purge gas for a first time;
step iii-b: vaporizing and injecting the film quality improver to the surface of a substrate loaded in a chamber;
Step iv-b: purging the interior of the chamber a second time with a purge gas;
step v-b: supplying a reaction gas into the chamber; and
Step vi-b: and purging the interior of the chamber with a purge gas a third time.
11. A semiconductor substrate, characterized in that,
The semiconductor substrate is manufactured by the molybdenum-based thin film forming method according to claim 6.
12. The semiconductor substrate according to claim 11, wherein,
The molybdenum-based film has a multilayer structure of two layers or three layers.
13. A semiconductor device, characterized in that,
Comprising the semiconductor substrate according to claim 11.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2021-0164643 | 2021-11-25 | ||
| KR1020220104489A KR20230077631A (en) | 2021-11-25 | 2022-08-22 | Thin film quality enhancer, method for forming thin film using the same, semiconductor substrate and semiconductor device prepared therefrom |
| KR10-2022-0104489 | 2022-08-22 | ||
| PCT/KR2022/017409 WO2023096216A1 (en) | 2021-11-25 | 2022-11-08 | Film quality improver, thin film forming method using same, semiconductor substrate manufactured therefrom, and semiconductor device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118234890A true CN118234890A (en) | 2024-06-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280074078.0A Pending CN118234890A (en) | 2021-11-25 | 2022-11-08 | Film quality improver, method for forming thin film using same, semiconductor substrate manufactured thereby, and semiconductor device |
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| Country | Link |
|---|---|
| CN (1) | CN118234890A (en) |
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- 2022-11-08 CN CN202280074078.0A patent/CN118234890A/en active Pending
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