Shielding compound, thin film forming method using the same, semiconductor substrate and semiconductor device manufactured therefrom

Abstract

The present invention relates to a shielding compound, a method for forming a thin film using the same, and a semiconductor substrate and a semiconductor device manufactured therefrom. The present invention provides a compound of a predetermined structure as a shielding compound, and forms a shielding region for a silicon-based thin film on a substrate, thereby reducing the deposition rate of the silicon-based thin film and appropriately reducing the growth rate of the thin film. This can significantly improve step coverage and film thickness uniformity even when a thin film is formed on a substrate with a complex structure, and has the effects of reducing corrosion and deterioration, improving the crystallinity of the thin film, and improving the electrical properties of the thin film.

Description

[Technical Field]

[0001] The present invention relates to a shielding compound, a method for forming a thin film using the same, a semiconductor substrate manufactured using the same, and a semiconductor device. More particularly, the present invention relates to a shielding compound that forms a shielding region for a silicon-based thin film on a substrate, thereby reducing the deposition rate of the silicon-based thin film and appropriately reducing the growth rate of the thin film, thereby significantly improving step coverage and film thickness uniformity of the thin film even when the thin film is formed on a substrate with a complex structure, a method for forming a thin film using the same, and a semiconductor substrate manufactured using the same. [Background technology]

[0002] As memory and non-memory semiconductor devices continue to become more and more integrated and their structures become more and more complex, step coverage becomes increasingly important when depositing a wide variety of thin films onto a substrate.

[0003] The semiconductor thin film is made of a nitride film, an oxide film, a metal film, etc. Examples of the nitride film include silicon nitride (SiN), titanium nitride (TiN), and tantalum nitride (TaN), examples of the oxide film include silicon oxide (SiO), hafnium oxide (HfO), and zirconium oxide (ZrO), and examples of the metal film include molybdenum (Mo), tungsten (W), and ruthenium (Ru).

[0004] The thin film is generally used as a diffusion barrier between the silicon layer of a doped semiconductor and aluminum (Al) or copper (Cu) used as an interlayer wiring material, but is also used as an adhesion layer when depositing a tungsten (W) thin film on a substrate.

[0005] In order for a thin film deposited on a substrate to have good and uniform physical properties, it is essential that the formed thin film has high step coverage.Thus, although the atomic layer deposition (ALD) process, which utilizes surface reactions, is more widely used than the chemical vapor deposition (CVD) process, which mainly utilizes gas phase reactions, there are still problems in achieving 100% step coverage.

[0006] Furthermore, one method proposed for improving step coverage is to reduce the thin film growth rate. However, when the deposition temperature is reduced to reduce the thin film growth rate, the amount of impurities such as carbon and chlorine remaining in the thin film increases, resulting in a significant deterioration in film quality.

[0007] Furthermore, process by-products such as chlorides remain in the manufactured thin film, which causes corrosion of metals such as aluminum and generates non-volatile by-products, resulting in deterioration of the film quality.

[0008] Therefore, there is a need for a thin film formation method that can effectively form thin films with complex structures even at high temperatures, has low impurity residue, and significantly improves step coverage and thin film thickness uniformity, as well as for the development of semiconductor substrates manufactured using the method.

[0009] [Prior art document]

[0010] [Patent Documents]

[0011] Republic of Korea Publication Patent No. 2011-0048195 Summary of the Invention [Problem to be solved by the invention]

[0012] In order to solve the above-mentioned problems of the prior art, the present invention aims to provide a shielding compound that forms a shielding region for a silicon-based thin film on a substrate, thereby reducing the deposition rate of the silicon-based thin film and appropriately lowering the growth rate of the thin film, thereby significantly improving step coverage and thin film thickness uniformity even when the thin film is formed on a substrate with a complex structure, a thin film formation method using the same, and a semiconductor substrate manufactured using the same.

[0013] The present invention aims to improve the density and electrical properties of a thin film by improving the crystallinity of the thin film.

[0014] The above and other objects of the present invention can all be achieved by the present invention described below. [Means for solving the problem]

[0015] In order to achieve the above object, the present invention provides a shielding compound for silicon-based thin films, comprising:

[0016] The silicon-based thin film has a film composition of SixNy (x and y are each an integer of 0.5 to 4.5),

[0017] The shielding compound has the following chemical formula 1:

[0018] [Chemical formula 1]

[0019] [ka]

[0020] (wherein A is carbon,

[0021] R1 and R3 are independently an alkyl group having 1 to 6 carbon atoms,

[0022] R2 independently has an alkyl group having 1 to 6 carbon atoms or a functional group of the formula BR4R5R6, B is a carbon bonded to A, and R4, R5, and R6 independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, fluorine (F), chlorine (Cl), bromine (Br), or iodine (I);

[0023] The X is a halogen element, and is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). The present invention provides a shielding compound for silicon-based thin films, which is a saturated compound represented by the formula:

[0024] The shielding compound may have a refractive index (a) in the range of 1.38 to 1.52, and a vapor pressure (25°C, mmHg, b) divided by the refractive index (a), (b / a), in the range of 0.003 to 0.033.

[0025] The silicon-based thin film may be composed of Si3N4, Si2N3, Si2N, SiN, or a mixture thereof.

[0026] The shielding compound may provide a shielding region for a silicon-based thin film.

[0027] The shielding region for the silicon-based thin film does not remain in the silicon-based thin film, and the silicon-based thin film may contain less than 0.01 wt % of a halogen element.

[0028] The silicon-based thin film may be used as a diffusion barrier film, an etching stop film, or a charge trap.

[0029]

[0030] The present invention also provides a compound represented by the following chemical formula 1:

[0031] [Chemical formula 1]

[0032] [ka]

[0033] (wherein A is carbon,

[0034] R1 and R3 are independently an alkyl group having 1 to 6 carbon atoms,

[0035] R2 independently has an alkyl group having 1 to 6 carbon atoms or a functional group of the formula BR4R5R6, B is a carbon bonded to A, and R4, R5, and R6 independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, fluorine (F), chlorine (Cl), bromine (Br), or iodine (I);

[0036] The X is a halogen element, and is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). The present invention provides a method for forming a silicon-based thin film, comprising the step of injecting a saturated structure shielding compound represented by the formula (I) into a chamber to shield the surface of a substrate loaded therein.

[0037]

[0038] vaporizing the shielding compound to form a shielding region on a surface of a substrate loaded into the chamber;

[0039] a step of first purging the inside of the chamber with a purge gas;

[0040] vaporizing a precursor compound and adsorbing it in an area outside the shielded area;

[0041] a step of secondarily purging the interior of the chamber with a purge gas;

[0042] supplying a reaction gas into the chamber;

[0043] and a third step of purging the interior of the chamber with a purge gas.

[0044]

[0045] a step of vaporizing a precursor compound and adsorbing it onto a surface of a substrate loaded into a chamber;

[0046] a step of first purging the inside of the chamber with a purge gas;

[0047] vaporizing a precursor compound to shield a surface of a substrate loaded into the chamber;

[0048] a step of secondarily purging the interior of the chamber with a purge gas;

[0049] supplying a reaction gas into the chamber;

[0050] and a third step of purging the interior of the chamber with a purge gas.

[0051]

[0052] For example, the precursor compound may be a molecule composed of Si and one or more elements selected from the group consisting of C, N, H, and Cl, and preferably a molecule composed of Si, H, and Cl. In this case, the deposition rate can be reduced while the resulting silicon-based thin film can contain less than 0.01% halogen elements.

[0053] The precursor compound may be a silicon precursor having a vapor pressure at 25°C of greater than 2 mTorr to 75 KTorr.

[0054] The chamber can be an atomic layer deposition (ALD) chamber or a chemical vapor deposition (CVD) chamber.

[0055] The shielding or precursor compound may be vaporized and injected followed by a plasma post-treatment step.

[0056] The amount of purge gas introduced into the chamber in each of the first purge step and the second purge step may be 10 to 100,000 times the volume of the introduced shielding compound.

[0057] The reactive gas is a nitriding agent, and the reactive gas, shielding compound, and precursor compound can be delivered into the chamber by a vapor flow control (VFC) method, a direct liquid introduction (DLI) method, or a liquid delivery system (LDS) method.

[0058] The substrate carried into the chamber can be heated to 300 to 800°C, specifically, 500 to 700°C.

[0059] The ratio of the amounts (mg / cycle) of the shielding compound and the precursor compound introduced into the chamber may be 1:1.5 to 1:20, and specifically, 1:3 to 1:15.

[0060]

[0061] The present invention also provides a semiconductor substrate manufactured by the above-described method for forming a silicon-based thin film.

[0062] The silicon-based thin film may have a multi-layer structure of two or three layers.

[0063] The silicon-based thin film may be a Si-rich thin film, or may be a partial region of a Si-rich thin film or an N-rich thin film.

[0064] The present invention further provides a semiconductor device including the semiconductor substrate described above.

[0065] The semiconductor substrate can be low resistive metal gate interconnects, high aspect ratio 3D metal-insulator-metal (MIM) capacitors, DRAM trench capacitors, 3D gate-all-around (GAA), or 3D NAND. [Effects of the Invention]

[0066] According to the present invention, it is possible to provide a shielding compound that improves the deposition rate of a silicon-based thin film by forming a shielding region for the silicon-based thin film on a substrate, appropriately reduces the thin film growth rate, and improves step coverage even when a thin film is formed on a substrate with a complex structure.

[0067] Furthermore, the by-products generated during the formation of the thin film are more effectively reduced, preventing corrosion and deterioration, and improving the crystallinity of the thin film, thereby improving the roughness, dielectric constant and electrical properties of the thin film.

[0068] Furthermore, the present invention has the effect of reducing process by-products during thin film formation, improving step coverage and thin film density, and further providing a thin film formation method using the same and a semiconductor substrate manufactured therefrom. [Brief explanation of the drawings]

[0069] [Figure 1] 1 is a graph showing the analysis results of secondary ion mass spectrometry (SIMS) of SiN thin films produced in Example 1 using the shielding compound used in the present invention and Comparative Example 1 not using the shielding compound.

[0070] [Figure 2]1 is a graph showing the change in deposition rate depending on the supply time of the shielding compound used in the present invention.

[0071] [Figure 3] 10 is a graph showing the results of elemental analysis by depth using Ar sputtering for the SiN thin films produced in Examples 3 and 4 and Comparative Example 4.

[0072] [Figure 4] 1 is a graph showing an analysis of the SiN thin films produced in Example 3 and Comparative Example 4 by secondary ion mass spectrometry (SIMS).

[0073] [Figure 5] 10 is a transmission electron microscope (TEM) photograph showing step coverage of a SiN thin film deposited using a trench substrate having an aspect ratio of 23:1 in Examples 3 to 4 and Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0074] The above-described shielding compound for silicon-based thin films, a method for forming silicon-based thin films using the same, and semiconductor substrates manufactured therefrom will be described in detail below.

[0075] Unless otherwise specified, the term "shielding" used in this description means not only reducing, preventing, or blocking the adsorption of precursor compounds for forming silicon-based thin films onto a substrate, but also reducing, preventing, or blocking the adsorption of process by-products onto a substrate.

[0076] The terms "partial region" or "partial substrate" used in this description refer to a portion of a specific layer relative to the horizontal plane of the substrate, or to a portion of a specific layer relative to the vertical plane of the substrate, unless otherwise specified.

[0077]

[0078] The present inventors have discovered that when a shielding compound that shields a precursor compound for forming a silicon-based thin film on the surface of a substrate loaded into a chamber is used, a shielding region that does not remain in the silicon-based thin film is formed at a reduced deposition rate, and the growth rate of the thin film is significantly reduced, ensuring the uniformity of the thin film even when applied to a substrate with a complex structure, significantly improving step coverage, and in particular, enabling thin film deposition and reducing the amount of halide remaining as a process by-product and the amount of carbon that is difficult to reduce even when using excessive reducing gas. Based on this discovery, the present inventors have conducted research into shielding compounds that provide a shielding region, leading to the completion of the present invention.

[0079]

[0080] The shielding compound of the present invention provides a shielding compound for silicon-based thin films.

[0081] Examples of the silicon-based thin film include SiH4, SiCl4, SiF4, SiCl2H2, Si2Cl6, TEOS, DIPAS, BTBAS, (NH2)Si(NHMe)3, (NH2)Si(NHEt)3, (NH2)Si(NH n Pr)3, (NH2)Si(NH i Pr)3, (NH2)Si(NH n Bu)3, (NH2)Si(NH i Bu)3, (NH2)Si(NH t Bu)3, (NMe2)Si(NHMe)3, (NMe2)Si(NHEt)3, (NMe2)Si(NH n Pr)3, (NMe2)Si(NH i Pr)3, (NMe2)Si(NH n Bu), (NMe)Si(NH i Bu), (NMe)Si(NH t Bu)3, (NEt2)Si(NHMe)3, (NEt2)Si(NHEt)3, (NEt2)Si(NH n Pr), (NEt)Si(NH i Pr), (NEt)Si(NH nBu)3、(NEt2)Si(NH i Bu)3、(NEt2)Si(NH t Bu)3、(N n Pr2)Si(NHMe)3、(N n Pr2)Si(NHEt)3、(N n Pr2)Si(NH n Pr)3、(N n Pr2)Si(NH i Pr)3、(N n Pr2)Si(NH n Bu)3、(N n Pr2)Si(NH i Bu)3、(N n Pr2)Si(NH t Bu)3、(N i Pr2)Si(NHMe)3、(N i Pr2)Si(NHEt)3、(N i Pr2)Si(NH n Pr)3、(N i Pr2)Si(NH i Pr)3、(N i Pr2)Si(NH n Bu)3、(N i Pr2)Si(NH i Bu)3、(N i Pr2)Si(NH t Bu)3、(N n Bu2)Si(NHMe)3、(N n Bu2)Si(NHEt)3、(N n Bu2)Si(NH n Pr)3、(N n Bu2)Si(NH i Pr)3、(N n Bu2)Si(NH n Bu)3、(N n Bu2)Si(NH i Bu)3、(N n Bu2)Si(NH t Bu)3、(N i Bu2)Si(NHMe)3、 (N i Bu2)Si(NHEt)3、(N i Bu2)Si(NH n Pr)3、(N iBu2)Si(NH i Pr)3、(N i Bu2)Si(NH n Bu)3、(N i Bu2)Si(NH i Bu)3、(N i Bu2)Si(NH t Bu)3、(N t Bu2)Si(NHMe)3、(N t Bu2)Si(NHEt)3、(N t Bu2)Si(NH n Pr)3、(N t Bu2)Si(NH i Pr)3、(N t Bu2)Si(NH n Bu)3、(N t Bu2)Si(NH i Bu)3、(N t Bu2)Si(NH t Bu)3、(NH2)2Si(NHMe)2、(NH2)2Si(NHEt)2、(NH2)2Si(NH n Pr)2、(NH2)2Si(NH i Pr)2、(NH2)2Si(NH n Bu)2、(NH2)2Si(NH i Bu)2、(NH2)2Si(NH t Bu)2、(NMe2)2Si(NHMe)2、(NMe2)2Si(NHEt)2、(NMe2)2Si(NH n Pr)2、(NMe2)2Si(NH i Pr)2、(NMe2)2Si(NH n Bu)2、(NMe2)2Si(NH i Bu)2、(NMe2)2Si(NH t Bu)2、(NEt2)2Si(NHMe)2、(NEt2)2Si(NHEt)2、(NEt2)2Si(NH n Pr)2、(NEt2)2Si(NH i Pr)2、(NEt2)2Si(NH n Bu)2、(NEt2)2Si(NH i Bu)2、(NEt2)2Si(NH t Bu)2、(N n Pr2)2Si(NHMe)2、(Nn Pr2)2Si(NHEt)2、(N n Pr2)2Si(NH n Pr)2、(N n Pr2)2Si(NH i Pr)2、(N n Pr2)2Si(NH n Bu)2、(N n Pr2)2Si(NH i Bu)2、(N n Pr2)2Si(NH t Bu)2、(N i Pr2)2Si(NHMe)2、(N i Pr2)2Si(NHEt)2、(N i Pr2)2Si(NH n Pr)2、(N i Pr2)2Si(NH i Pr)2、 (N i Pr2)2Si(NH n Bu)2、(N i Pr2)2Si(NH i Bu)2、(N i Pr2)2Si(NH t Bu)2、(N n Bu2)2Si(NHMe)2、(N n Bu2)2Si(NHEt)2、(N n Bu2)2Si(NH n Pr)2、(N n Bu2)2Si(NH i Pr)2、(N n Bu2)2Si(NH n Bu)2、(N n Bu2)2Si(NH i Bu)2、(N n Bu2)2Si(NH t Bu)2、(N i Bu2)2Si(NHMe)2、(N i Bu2)2Si(NHEt)2、(N i Bu2)2Si(NH n Pr)2、(N i Bu2)2Si(NH i Pr)2、(N i Bu2)2Si(NH n Bu)2、(Ni Bu2)2Si(NH i Bu)2、(N i Bu2)2Si(NH t Bu)2、(N t Bu2)2Si(NHMe)2、(N t Bu2)2Si(NHEt)2、(N t Bu2)2Si(NH n Pr)2、(N t Bu2)2Si(NH i Pr)2、(N t Bu2)2Si(NH n Bu)2、(N t Bu2)2Si(NH i Bu)2、(N t Bu2)2Si(NH t Bu)2、Si(HNCH2CH2NH)2、Si(MeNCH2CH2NMe)2, Si(EtNCH2CH2NEt)2、Si( n PrNCH2CH2N n Pr)2、Si( i PrNCH2CH2N i Pr)2、Si( n BuNCH2CH2N n Bu)2、Si( i BuNCH2CH2N i Bu)2、Si( t BuNCH2CH2N t Bu)2、Si(HNCHCHNH)2、Si(MeNCHCHNMe)2、Si(EtNCHCHNEt)2、Si( n PrNCHCHN n Pr)2、Si( i PrNCHCHN i Pr)2、Si( n BuNCHCHN n Bu)2、Si( i BuNCHCHN i Bu)2、Si( t BuNCHCHN t Bu)2、(HNCHCHNH)Si(HNCH2CH2NH)、(MeNCHCHNMe)Si(MeNCH2CH2NMe)、(EtNCHCHNEt)Si(EtNCH2CH2NEt)、( nPrNCHCHN n Pr)Si( n PrNCH2CH2N n Pr)、( i PrNCHCHN i Pr)Si( i PrNCH2CH2N i Pr)、( n This is it. n Bu(Si( n This is CH2CH2N. n This)、( i This is it. i Bu(Si( i This is CH2CH2N. i This)、( t This is it. t Bu(Si( t This is CH2CH2N. t This)、(NH t Bu)2Si(HNCH2CH2NH)、(NH t Bu)2Si(MeNCH2CH2NMe)、(NH t Bu)2Si(EtNCH2CH2NEt)、 (NH t This is)2Si( n PrNCH2CH2N n Pr)、(NH t This is)2Si( i PrNCH2CH2N i Pr)、(NH t This is)2Si( n This is CH2CH2N. n This)、(NH t This is)2Si( i This is CH2CH2N. i This)、(NH t This is)2Si( t This is CH2CH2N. t This)、(NH t Bu)2Si(HNCHCHNH)、(NH t Bu)2Si(MeNCHCHNMe) , (NH t Bu)2Si(EtNCHCHNEt)、(NH t This is)2Si( n PrNCHCHN nPr)、(NH t Bu)2Si( i PrNCHCHN i Pr)、(NH t Bu)2Si( n BuNCHCHN n Bu)、(NH t Bu)2Si( i BuNCHCHN i Bu)、(NH t Bu)2Si( t BuNCHCHN t ( i PrNCH2CH2N i Pr)Si(NHMe)2、( i PrNCH2CH2N i Pr)Si(NHEt)2、( i PrNCH2CH2N i Pr)Si(NH n Pr)2、( i PrNCH2CH2N i Pr)Si(NH i Pr)2、( i PrNCH2CH2N i Pr)Si(NH n Bu)2、( i PrNCH2CH2N i Pr)Si(NH i Bu)2、( i PrNCH2CH2N i Pr)Si(NH t Bu)2、( i PrNCHCHN i Pr)Si(NHMe)2、( i PrNCHCHN i Pr)Si(NHEt)2、( i PrNCHCHN i Pr)Si(NH n Pr)2、( i PrNCHCHN i Pr)Si(NH i Pr)2、( i PrNCHCHN i Pr)Si(NH n Bu)2、( i PrNCHCHN i Pr)Si(NH iBu)2 and ( i PrNCHCHN i Pr)Si(NH t Bu)2, in which case the effects to be achieved in the present invention can be sufficiently obtained.

[0082] The aforementioned n Pr means n-propyl; i Pr means isopropyl; n Bu stands for n-butyl, i Bu stands for isobutyl, t Bu means tert-butyl.

[0083] The silicon-based thin film may have a film composition of SixNy, as a specific example.

[0084] Here, x and y can each be an integer between 0.5 and 4.5.

[0085] Preferably, the x and y are each an integer of 2.5 to 4.5.

[0086]

[0087] The silicon-based thin film may be made of Si3N4, Si2N3, Si2N, SiN, or a mixture thereof, but is not limited thereto and also includes SiH and SiOH.

[0088] The silicon-based thin film can be used in semiconductor devices not only as a commonly used diffusion barrier film but also as an etching stop film or a charge trap.

[0089]

[0090] The shielding compound has the following chemical formula 1:

[0091] [Chemical formula 1]

[0092] [ka]

[0093] (wherein A is carbon,

[0094] R1 and R3 are independently an alkyl group having 1 to 6 carbon atoms,

[0095] R2 independently has an alkyl group having 1 to 6 carbon atoms or a functional group of the formula BR4R5R6, B is a carbon bonded to A, and R4, R5, and R6 independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, fluorine (F), chlorine (Cl), bromine (Br), or iodine (I);

[0096] The X is a halogen element, and is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). In this case, when forming a silicon-based thin film, a shielding region that does not remain in the silicon-based thin film is formed at a reduced deposition rate, side reactions are suppressed, the thin film growth rate is adjusted, process by-products in the thin film are reduced, corrosion and deterioration are reduced, and the crystallinity of the thin film is improved. Therefore, even when a thin film is formed on a substrate having a complex structure, the step coverage and the thickness uniformity of the thin film are significantly improved.

[0097] In the above Chemical Formula 1, A is carbon.

[0098] R1, R2, and R3 are each independently an alkyl group having 1 to 6 carbon atoms, with at least one of them having 2 or 5 carbon atoms. As a preferred example, any one of R1, R2, and R3 has 1 carbon atom, and the remaining two have 2 or 3 carbon atoms. More preferably, any one of R1, R2, and R3 has 1 carbon atom, and the remaining two have 2 carbon atoms. Within this range, there are advantages such as a significant reduction in process by-products, excellent step coverage, improved thin film density, and even better thin film electrical properties.

[0099] In Formula 1, X is a halogen element, preferably fluorine, chlorine, or bromine, more preferably chlorine or bromine, and within this range, there are advantages in that the effect of reducing process by-products and the effect of improving step coverage are more outstanding. Furthermore, X may be, for example, fluorine, which is advantageous in that it is more suitable for processes requiring high-temperature deposition.

[0100] In Formula 1, X may be iodine as another preferred example. Within this range, there are advantages in that the thin film crystallinity is improved and side reactions are suppressed, resulting in an even more significant reduction in process by-products.

[0101]

[0102] The compound represented by Chemical Formula 1 is a tertiary alkyl compound substituted with halogen, and specific examples thereof include 2-chloro-2-methylpropane, 2-chloro-2-methylbutane, 2-chloro-2-methylpentane, 3-chloro-3-methylpentane, 3-chloro-3-methylhexane, 3-chloro-3-ethylpentane, 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 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 methylbutane, 2-iodo-2 methylpentane, 3-iodo-3 methylpentane, 3-iodo-3 methylhexane, 3-iodo-3 ethylpentane, 3-iodo-3 ethylhexane, 4-iodo-4 methylheptane, 4-iodo-4 ethylheptane, 4-iodo-4 propylheptane butyl ether, 2-fluoro-2-methylpropane, 2-fluoro-2-methylbutane, 2-fluoro-2-methylpentane, 3-fluoro-3-methylpentane, 3-fluoro-3-methylhexane, 3-fluoro-3-ethylpentane, 3-fluoro-3-ethylhexane, 4-fluoro-4-methylheptane, 4-fluoro-4-ethylheptane, and 4-fluoro-4-propylheptane, and preferably 2-chloro-2-methylpropane, 2-chloro-2-methylbutane, 3-chloro-3-methylpentane, tert-butyl chloride, 2-bromo-2-methylbutane, 2-chloro-2-methylpentane, 3-fluoro-3-methylpentane, 3-fluoro-3-methylhexane, 3-fluoro-3-ethylpentane, 3-fluoro-3-ethylhexane, 4-fluoro-4-methylheptane, 4-fluoro-4-ethylheptane, and 4-fluoro-4-propylheptane. and at least one selected from the group consisting of 2-iodo-2-methylpropane, 2-bromo-2-methylbutane, 3-bromo-3-methylpentane, tert-butyl bromide, 2-iodo-2-methylpropane, 2-iodo-2-methylbutane, 3-iodo-3-methylpentane, tert-butyl iodide, 2-fluoro-2-methylpropane, 2-fluoro-2-methylbutane, 3-fluoro-3-methylpentane, and tert-butyl fluoride. In this case, the effect of providing a shielding region for the silicon thin film to adjust the growth rate of the thin film is significant, and the effect of removing process by-products is also significant.It has excellent step coverage and is also extremely effective in improving film quality.

[0103]

[0104] The compound represented by Chemical Formula 1 may be, for example, a saturated compound having a refractive index (a) in the range of 1.38 to 1.52, and a vapor pressure (mmHg, b) measured at 25° C. divided by the refractive index (a), (b / a), in the range of 0.003 to 0.033. In this case, a shielding region for the silicon-based thin film is formed on the substrate to reduce the deposition rate of the silicon-based thin film, appropriately reducing the thin film growth rate, thereby significantly improving step coverage and thin film thickness uniformity even when a thin film is formed on a substrate with a complex structure, and effectively protecting the substrate surface by preventing the adsorption of not only the thin film precursor but also process by-products, and effectively removing the process by-products.

[0105] The compound represented by Chemical Formula 1 may be, for example, a saturated compound having a refractive index (a) in the range of 1.38 to 1.51, and a vapor pressure (mmHg, b) measured at 25°C divided by the refractive index (a) (b / a) in the range of 0.003 to 0.0325. Preferably, the compound may be a saturated compound having a refractive index (a) in the range of 1.383 to 1.505, and a vapor pressure (mmHg, b) measured at 25°C divided by the refractive index (a) (b / a) in the range of 0.0035 to 0.0324. In this case, a shielding region for the silicon-based thin film is formed on the substrate, thereby reducing the deposition rate of the silicon-based thin film and appropriately reducing the growth rate of the thin film. This significantly improves step coverage and thickness uniformity of the thin film, even when the thin film is formed on a substrate with a complex structure. It also has the advantages of effectively protecting the substrate surface by preventing the adsorption of not only the thin film precursor but also process by-products, and effectively removing the process by-products.

[0106]

[0107] The shielding compound may provide a shielding region for a silicon-based thin film.

[0108] For example, the shielding region for the silicon-based thin film may be formed on the entire substrate or a portion of the substrate on which the silicon-based thin film is formed.

[0109]

[0110] The shielding region for the silicon-based thin film is characterized in that it does not remain on the silicon-based thin film.

[0111] In this case, unless otherwise specified, "not remaining" refers to the presence of C element at 0.1 atomic % (atom %), Si element at less than 0.1 atomic % (atom %), N element at less than 0.1 atomic % (atom %), and halogen elements at less than 0.1 atomic % (atom %) when the components are analyzed by X-ray Photoelectron Spectroscopy (XPS).

[0112] As a specific example, the silicon-based thin film may contain 0.01% or less of a halogen compound.

[0113] The silicon-based thin film can be used as a diffusion barrier film, an etching stop film, or a charge trap, but is not limited to these.

[0114] The shielding compound may preferably be a compound with a purity of 99.9% or more, a compound with a purity of 99.95% or more, or a compound with a purity of 99.99% or more. For reference, when using a compound with a purity of less than 99%, there is a risk of forming impurities, so it is preferable to use a substance with a purity of 99% or more whenever possible.

[0115]

[0116] The compound represented by Formula 1 is preferably used in an atomic layer deposition (ALD) process, and in this case, it has the advantages of not interfering with the adsorption of precursor compounds, but effectively protecting the substrate surface by being used as a shielding compound, and effectively removing process by-products.

[0117] The compound represented by Chemical Formula 1 is preferably a liquid at room temperature (25°C) and has a density of 0.8 to 2.5 g / cm 3 or 0.8 to 1.5 g / cm 3 The vapor pressure (20°C) is 0.1 to 300 mmHg or 1 to 300 mmHg, and the solubility in water (25°C) can be 200 mg / L or less. Within this range, the shielding region is effectively formed, and the step coverage and the uniformity of the thin film thickness are excellent, and further, the film quality is remarkably improved.

[0118] More preferably, the compound represented by Chemical Formula 1 has a density of 0.75 to 2.0 g / cm 3 or 0.8 to 1.3 g / cm 3 The vapor pressure (20°C) is 1 to 260 mmHg, and the solubility in water (25°C) can be 160 mg / L or less. Within this range, the shielding region is effectively formed, and the step coverage and thin film thickness uniformity are excellent, and further, the film quality is remarkably improved.

[0119]

[0120] The method for forming a silicon-based thin film of the present invention comprises reacting a silicon-based thin film with a compound represented by the following chemical formula 1

[0121] [Chemical formula 1]

[0122] [ka]

[0123] (wherein A is carbon,

[0124] R1 and R3 are independently an alkyl group having 1 to 6 carbon atoms,

[0125] R2 independently has an alkyl group having 1 to 6 carbon atoms or a functional group of the formula BR4R5R6, B is a carbon bonded to A, and R4, R5, and R6 independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, fluorine (F), chlorine (Cl), bromine (Br), or iodine (I);

[0126] The X is a halogen element, and is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). and adsorbing the shielding compound represented by the formula (I) into the ALD chamber to the surface of the loaded substrate. In this case, a shielding region for the silicon-based thin film is formed on the substrate, thereby reducing the deposition rate of the silicon-based thin film and appropriately lowering the thin film growth rate, thereby significantly improving step coverage and film thickness uniformity even when a thin film is formed on a substrate with a complex structure.

[0127] In the step of shielding the shielding compound onto the surface of the substrate, the feeding time of the shielding compound onto the surface of the substrate is preferably 0.01 to 20 seconds per cycle, more preferably 0.02 to 20 seconds, even more preferably 0.04 to 20 seconds, and even more preferably 0.05 to 20 seconds. Within this range, there are advantages such as a low thin film growth rate, excellent step coverage, and cost-effectiveness.

[0128] In this description, the feeding time of the shielding compound is based on a chamber volume of 15-20 L and a flow rate of 0.5-5 mg / second (mg / s), and more specifically, on a chamber volume of 18 L and a flow rate of 1-2 mg / s.

[0129]

[0130] In a preferred embodiment, the thin film formation method may include the steps of vaporizing the shielding compound to shield the surface of a substrate loaded into an ALD chamber, first purging the interior of the chamber with a purge gas, vaporizing a precursor compound to adsorb onto the surface of the substrate loaded into the chamber, second purging the interior of the chamber with a purge gas, supplying a reaction gas into the chamber, and third purging the interior of the chamber with a purge gas. In this case, the shielding step, the third purging step, and the third purging step constitute a unit cycle, which can be repeated until a thin film of a desired thickness is obtained. In this way, when the shielding compound of the present invention is introduced before the precursor compound in one cycle and adsorbed onto the substrate, there are advantages in that the thin film growth rate can be appropriately reduced even when deposition is performed at high temperatures, and the resistivity of the thin film can be reduced by effectively removing process by-products that are generated, thereby significantly improving step coverage.

[0131]

[0132] In yet another preferred embodiment, the thin film formation method may include the steps of vaporizing a precursor compound and adsorbing it onto the surface of a substrate loaded into a chamber, first purging the interior of the chamber with a purge gas, vaporizing the shielding compound and adsorbing it onto the surface of a substrate loaded into the chamber, second purging the interior of the chamber with a purge gas, supplying a reaction gas into the chamber, and tertiary purging the interior of the chamber with a purge gas. In this case, the shielding step to the tertiary purging step are defined as a unit cycle, and the cycle can be repeated until a thin film of a desired thickness is obtained. In this way, when the shielding compound of the present invention is introduced after the precursor compound within one cycle and adsorbed onto the substrate, the shielding compound can act as an activator for thin film formation, which has the advantages of increasing the growth rate of the thin film, increasing the density and crystallinity of the thin film, reducing the resistivity of the thin film, and significantly improving its electrical properties.

[0133]

[0134] In a preferred example of the thin film formation method of the present invention, the shielding compound of the present invention can be added before the precursor compound in one cycle and adsorbed onto the substrate. In this case, even if the thin film is deposited at a high temperature, the thin film growth rate can be appropriately reduced, thereby significantly reducing process by-products, significantly improving step coverage, and increasing the crystallinity of the thin film, thereby reducing the thin film's resistivity. This has the advantage of significantly improving the film thickness uniformity and ensuring the reliability of the semiconductor device, even when applied to a semiconductor device with a large aspect ratio.

[0135]

[0136] For example, in the thin film formation method, when the shielding compound is deposited before or after the precursor compound is deposited, the unit cycle can be repeated 1 to 99,999 times as needed, preferably 10 to 10,000 times, more preferably 50 to 5,000 times, and even more preferably 100 to 2,000 times. Within these ranges, the desired thin film thickness can be obtained, while the effects to be achieved in the present invention can be sufficiently achieved.

[0137]

[0138] The precursor compound is a molecule composed of Si and one or more selected from the group consisting of C, N, H, and Cl, and when the precursor compound is a silicon precursor having a vapor pressure of 2 mTorr to 75 KTorr at 25°C, the effect of forming a shielding region by the shielding compound can be maximized despite natural oxidation.

[0139] In the present invention, the chamber may be, for example, an ALD chamber or a CVD chamber.

[0140] In the present invention, the shielding compound or precursor compound may be vaporized and injected, followed by a plasma post-treatment step, in which case the growth rate of the thin film can be adjusted while reducing process by-products.

[0141]

[0142] When the shielding compound is first adsorbed onto a substrate and then the precursor compound is adsorbed onto the substrate, or when the precursor compound is first adsorbed onto the substrate and then the shielding compound is adsorbed onto the substrate, the amount of purge gas introduced into the chamber in the step of purging the unadsorbed shielding compound is not particularly limited as long as it is an amount sufficient to remove the unadsorbed shielding compound, but may be, for example, 10 to 100,000 times, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times. Within this range, the unadsorbed shielding compound can be sufficiently removed to form a uniform thin film and prevent deterioration of film quality. Here, the amounts of the purge gas and the shielding compound introduced are each based on one cycle, and the volume of the shielding compound refers to the volume of vaporized shielding compound vapor.

[0143] As a specific example, when the shielding compound is injected (per cycle) at a flow rate of 1.66 mL / s and an injection time of 0.5 seconds (sec), and in the step of purging unadsorbed shielding compound, a purge gas is injected (per cycle) at a flow rate of 166.6 mL / s and an injection time of 3 seconds, the injection amount of the purge gas is 602 times the injection amount of the shielding compound.

[0144]

[0145] Furthermore, in the step of purging the unadsorbed precursor compound, the amount of purge gas introduced into the ALD chamber is not particularly limited as long as it is an amount sufficient to remove the unadsorbed precursor compound, but for example, it may be 10 to 10,000 times, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times the volume of the precursor compound introduced into the ALD chamber. Within this range, the unadsorbed precursor compound can be sufficiently removed, resulting in the formation of a uniform thin film and preventing deterioration of film quality. Here, the amounts of the purge gas and precursor compound introduced are each based on one cycle, and the volume of the precursor compound refers to the volume of vaporized precursor compound vapor.

[0146]

[0147] Furthermore, in the purge step performed immediately after the reaction gas supply step, the amount of purge gas introduced into the ALD chamber may be, for example, 10 to 10,000 times, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times the volume of the reaction gas introduced into the ALD chamber, and the desired effects can be sufficiently obtained within these ranges. Here, the amounts of the purge gas and reaction gas introduced are each based on one cycle.

[0148]

[0149] The shielding compound and precursor compound can be preferably delivered into the ALD chamber by a vapor flow control (VFC) method, a direct liquid introduction (DLI) method, or a liquid delivery system (LDS) method, and more preferably delivered into the chamber by an LDS method.

[0150] The substrate carried into the chamber may be heated to, for example, 300 to 800°C, specifically, 500 to 700°C, and the shielding compound or precursor compound may be injected onto the substrate in an unheated or heated state. Depending on the deposition efficiency, the shielding compound or precursor compound may be injected unheated and then the heating conditions may be adjusted during the deposition process. For example, the shielding compound or precursor compound may be injected onto the substrate at a temperature of 300 to 800°C for 1 to 30 seconds.

[0151]

[0152] The ratio of the amounts (mg / cycle) of the shielding compound and the precursor compound introduced into the chamber may be preferably 1:1.5 to 1:20, more preferably 1:2 to 1:15, even more preferably 1:2 to 1:12, and even more preferably 1:2.5 to 1:10. Within this range, the effect of improving step coverage and the effect of reducing process by-products are significant.

[0153]

[0154] In the present invention, the precursor compound may be mixed with a non-polar solvent and then introduced into the chamber, which has the advantage that the viscosity and vapor pressure of the precursor compound can be easily adjusted.

[0155] The non-polar solvent may be at least one selected from the group consisting of alkanes and cycloalkanes. In this case, the non-polar solvent has the advantage of containing an organic solvent with very low reactivity and easy moisture control, while improving step coverage even when the deposition temperature is increased during thin film formation.

[0156] In a more preferred example, the non-polar solvent is a C1 to C 10 Alkanes of C3 to C 10 The cycloalkanes may include cycloalkanes of the formula C3 to C6. 10In this case, the reactivity is very low and moisture can be easily controlled.

[0157] In this description, C1, C3, etc. refer to the number of carbon atoms.

[0158] The cycloalkane is preferably a C3 to C 10 Among the monocycloalkanes, cyclopentane is liquid at room temperature and has the highest vapor pressure, so it is suitable for the vapor deposition process, but is not limited thereto.

[0159] The non-polar solvent has, for example, a solubility in water (25°C) of 200 mg / L or less, preferably 50 to 400 mg / L, and more preferably 135 to 175 mg / L. Within this range, the non-polar solvent has the advantage of low reactivity with the precursor compound and easy water management.

[0160] In this description, the solubility is not particularly limited to the measurement methods and standards commonly used in the technical field to which the present invention pertains, and as an example, a saturated solution can be measured by high performance liquid chromatography (HPLC).

[0161] The non-polar solvent preferably comprises 5 to 95% by weight, more preferably 10 to 90% by weight, even more preferably 40 to 90% by weight, and most preferably 70 to 90% by weight, based on the total weight of the precursor compound and the non-polar solvent.

[0162] If the content of the non-polar solvent exceeds the upper limit, impurities are generated, increasing the resistance and the number of impurities in the thin film. If the content of the organic solvent is below the lower limit, the effect of improving step coverage and reducing impurities such as chlorine (Cl) ions by adding the solvent is not very effective.

[0163]

[0164] In the method for forming a silicon-based thin film, when the shielding compound is used, for example, the decrease rate of the thin film growth rate per cycle (Å / cycle), calculated by the following mathematical formula 1, is −5% or less, preferably −10% or less, more preferably −20% or less, even more preferably −30% or less, still more preferably −40% or less, and most preferably −45% or less. Within this range, the step coverage and film thickness uniformity are excellent.

[0165] [Formula 1]

[0166] Decrease in film growth rate per cycle (%) = [(film growth rate per cycle with shielding compound - film growth rate per cycle without shielding compound) / film growth rate per cycle without shielding compound] x 100

[0167] In Equation 1, the thin film growth rate per cycle when a shielding compound is used and when a shielding compound is not used refers to the deposition thickness (Å / cycle) of the thin film per cycle, i.e., the deposition rate. The deposition rate can be calculated by, for example, measuring the final film thickness by ellipsometry and dividing the measured value by the total number of cycles to obtain an average deposition rate. For more accurate film thickness measurement, the ellipsometry measurement method was correlated with a transmission electron microscope (TEM) analysis to improve thickness error.

[0168] In the above formula 1, "when no shielding compound was used" means that a thin film is produced by adsorbing only a precursor compound onto a substrate during the thin film deposition process. Specifically, this refers to a case where a thin film is formed by omitting the steps of adsorbing a shielding compound and purging unadsorbed shielding compound from the thin film formation method.

[0169]

[0170] In the method for forming a silicon-based thin film, the residual halogen intensity (c / s) in the thin film based on a thin film thickness of 100 Å, as measured by secondary ion mass spectrometry (SIMS), is preferably 4,000 ppm or less, more preferably 3,700 ppm or less, even more preferably 3,500 ppm or less, and even more preferably 2,000 ppm or less, and more preferably 0 ppm or less, and within such a range, the method is highly effective in preventing corrosion and deterioration.

[0171] In this description, the purge flow rate is preferably 1,000 to 50,000 sccm (standard cubic centimeters per minute), more preferably 2,000 to 30,000 sccm, and even more preferably 2,500 to 15,000 sccm. Within this range, the thin film growth rate per cycle is appropriately controlled, and deposition is performed as or close to an atomic monolayer, which is advantageous in terms of film quality.

[0172]

[0173] ALD (atomic layer deposition) is highly advantageous in the fabrication of integrated circuits (ICs) that require high aspect ratios, and in particular, it has advantages such as excellent conformality, uniformity, and precise thickness control due to its self-limiting thin film growth mechanism.

[0174] The thin film formation method can be carried out at a deposition temperature in the range of, for example, 50 to 800°C, preferably 300 to 700°C, more preferably 500 to 700°C, and even more preferably 600 to 650°C. Within this range, it is possible to achieve the characteristics of the ALD process while growing a thin film with excellent film quality.

[0175] The thin film formation method can be carried out, for example, at a deposition pressure in the range of 0.01 to 20 Torr, preferably at a deposition pressure in the range of 0.1 to 20 Torr, more preferably at a deposition pressure in the range of 0.1 to 10 Torr, and most preferably at a deposition pressure in the range of 0.3 to 5 Torr. Within this range, a thin film with a uniform thickness can be obtained.

[0176] In this description, the deposition temperature and deposition pressure may be measured as the temperature and pressure formed in the deposition chamber, or may be measured as the temperature and pressure applied to the substrate in the deposition chamber.

[0177] The method for forming the silicon-based thin film may preferably include a step of raising the temperature in the chamber to a deposition temperature before introducing the shielding compound into the chamber, and / or a step of injecting an inert gas into the chamber to purge the chamber before introducing the shielding compound into the chamber.

[0178] Furthermore, the present invention may include a thin film manufacturing apparatus capable of realizing the silicon-based thin film manufacturing method, the thin film manufacturing apparatus including an ALD chamber, a first vaporizer that vaporizes a shielding compound, a first transport means that transports the vaporized shielding compound into the ALD chamber, a second vaporizer that vaporizes a thin film precursor, and a second transport means that transports the vaporized thin film precursor into the ALD chamber. Here, the vaporizer and the transport means are not particularly limited as long as they are vaporizers and transport means that are commonly used in the technical field to which the present invention pertains.

[0179]

[0180] To explain the thin film formation method in detail, first, a substrate on which a thin film is to be formed is placed in a deposition chamber capable of depositing atomic layers.

[0181] The substrate may encompass semiconductor substrates such as silicon substrates, silicon oxide, and the like.

[0182] The substrate may further have a conductive or insulating layer formed thereon.

[0183] To deposit a thin film on a substrate placed in the deposition chamber, the above-mentioned shielding compound and a precursor compound or a mixture thereof with a non-polar solvent are prepared.

[0184] The prepared shielding compound is then injected into a vaporizer, converted into a vapor phase, and delivered to a deposition chamber where it is adsorbed onto the substrate, followed by purging to remove any unadsorbed shielding compound.

[0185] Next, the prepared precursor compound or a mixture of the precursor compound and a non-polar solvent (thin film forming composition) is injected into a vaporizer, converted into a vapor phase, and transferred to a deposition chamber to be adsorbed onto a substrate, and unadsorbed precursor compound / thin film forming composition is purged.

[0186] In this description, the steps of adsorbing the shielding compound onto the substrate and then purging to remove any unadsorbed shielding compound and adsorbing the precursor compound onto the substrate and then purging to remove any unadsorbed precursor compound may be performed in different orders, if necessary.

[0187] In this description, the method for delivering the shielding compound and precursor compound (composition for forming a thin film) to the deposition chamber may be, for example, a method for delivering a vaporized gas using a mass flow controller (MFC) (Vapor Flow Control; VFC) or a method for delivering a liquid using a liquid mass flow controller (LMFC) (Liquid Delivery System; LDS), and preferably, an LDS method is used.

[0188] In this case, the carrier gas or dilution gas for transporting the shielding compound and precursor compound onto the substrate may be one or a mixture of two or more gases selected from the group consisting of argon (Ar), nitrogen (N), and helium (He), but is not limited thereto.

[0189] In this description, the purge gas may be, for example, an inert gas, and preferably, the carrier gas or dilution gas.

[0190]

[0191] Next, a reaction gas is supplied. The reaction gas may be any reaction gas commonly used in the art, but is not limited to a specific gas. Preferably, the reaction gas may include a nitriding agent. The nitriding agent reacts with the precursor compound adsorbed on the substrate to form a nitride film.

[0192] Preferably, the nitriding agent can be nitrogen gas (N2), hydrazine gas (N2H4), or a mixture of nitrogen gas and hydrogen gas.

[0193] The reactive gas may contain only hydrogen (H2), which reacts with the precursor compound adsorbed on the substrate to form a silicon film.

[0194]

[0195] The remaining unreacted reactant gas is then purged with an inert gas, which removes not only the excess reactant gas but also any by-products that are produced.

[0196] As described above, the method for forming a silicon-based thin film may, for example, include a unit cycle consisting of a step of shielding a shielding compound on a substrate, a step of purging unadsorbed shielding compound, a step of adsorbing a precursor compound / thin film-forming composition on a substrate, a step of purging unadsorbed precursor compound / thin film-forming composition, a step of supplying a reactive gas, and a step of purging residual reactive gas, and the unit cycle may be repeated to form a thin film of a desired thickness.

[0197] In another example, the silicon-based thin film forming method may have a unit cycle consisting of a step of adsorbing a precursor compound / thin film forming composition onto a substrate, a step of purging the unadsorbed precursor compound / thin film forming composition, a step of adsorbing a shielding compound onto a substrate, a step of purging the unadsorbed shielding compound, a step of supplying a reactive gas, and a step of purging the remaining reactive gas, and the unit cycle can be repeated to form a thin film of a desired thickness.

[0198] The unit cycle can be repeated, for example, 1 to 99,999 times, preferably 10 to 1,000 times, more preferably 50 to 5,000 times, and even more preferably 100 to 2,000 times. Within this range, the desired thin film properties are effectively exhibited.

[0199]

[0200] The present invention also provides a semiconductor substrate, characterized in that the semiconductor substrate is manufactured by the above-described method for forming a silicon-based thin film. In this case, the semiconductor substrate has the effect of being significantly superior in step coverage and thickness uniformity of the thin film, as well as superior density and electrical properties of the thin film.

[0201]

[0202] The thin film thus produced preferably has a thickness of 100 nm or less, an etching rate (WER @ LAL50060s) of <2 nm / min (nm / min) based on a thin film thickness of 10 or 20 nm, a residual carbon content and a halogen content both of 0.01% or less, and a step coverage of 90% or more. Within these ranges, the thin film exhibits excellent performance as an insulating film and a charge trapping layer, but is not limited thereto.

[0203] The thin film may have a thickness of, for example, 1 to 100 nm, preferably 1 to 50 nm, more preferably 3 to 25 nm, and even more preferably 5 to 20 nm, and within this range, the thin film has excellent thin film properties.

[0204] The thin film may have a residual carbon content of preferably 0.1% or less or 0 to 0.01%, more preferably 0 to 0.001%, and even more preferably 0 to 0.0001%, each of which has the effect of reducing the growth rate of the thin film while maintaining excellent thin film properties. Within this range, an appropriate carbon content in the thin film is characterized by forming deep trap sites within the band gap of the thin film to improve charge storage properties, improving film density, and improving etching rate, thereby exhibiting excellent insulating film properties. A lower residual halogen content in the thin film is preferred because it results in better film quality.

[0205] The thin film has, for example, a step coverage of 90% or more, preferably 92% or more, and more preferably 95% or more. Within this range, even thin films with complex structures can be easily deposited on substrates, and have the advantage of being applicable to next-generation semiconductor devices.

[0206]

[0207] The thin film thus produced is, for example, a silicon nitride film (Si x N y, where 0 < x ≤ 4.5, 0 < y ≤ 4.5, preferably, 0.5 ≤ x ≤ 4.5, 0.5 ≤ y ≤ 4.5, more preferably, 2.5 ≤ x ≤ 4.5, 2.5 ≤ y ≤ 4.5 can be included, and in this case, there is an advantage that it can be effectively used as a diffusion prevention film, an etching stop film, or a charge trap of a semiconductor element.

[0208]

[0209] The thin film may be, for example, a multilayer structure of two or three layers as necessary. The multilayer film having a two-layer structure may be, as a specific example, a structure of a lower layer film - a middle layer film, and the multilayer film having a three-layer structure may be, as a specific example, a structure of a lower layer film - a middle layer film - an upper layer film.

[0210] The lower layer film may include, for example, one or more selected from the group consisting of Si, SiO2, MgO, Al2O3, CaO, ZrSiO4, ZrO2, HfSiO4, Y2O3, HfO2, LaLuO2, Si3N4, SrO, La2O3, Ta2O5, BaO, TiO2.

[0211] The middle layer film may include, for example, Ti x N y , and preferably, may include TN.

[0212] The upper layer film may include, for example, one or more selected from the group consisting of W and Mo.

[0213]

[0214] Hereinafter, preferred examples and drawings for deepening the understanding of the present invention will be presented. However, the following examples and drawings are merely illustrative of the present invention, and it is obvious to those skilled in the art that various changes and modifications can be made within the scope of the present invention and the scope of the technical idea. Needless to say, such variations and modifications naturally also belong to the scope of the appended claims.

[0215]

[0216] [Example]

[0217] Example 1

[0218] Tert-butyl iodide was prepared as a shielding compound and Si2Cl6 as a thin film precursor compound.

[0219] The prepared shielding compound was placed in a canister and supplied to an evaporator heated to 120°C at a flow rate of 0.05 g / min using a liquid mass flow controller (LMFC) at room temperature. The shielding compound vaporized in the evaporator was then introduced into a deposition chamber containing a substrate for 1 second, after which argon gas was supplied at 5000 sccm for 2 seconds to perform an argon purge. The pressure inside the reaction chamber was controlled at 2.5 Torr.

[0220] The prepared Si2Cl6 was then placed in a separate canister and supplied to a separate evaporator heated to 150°C at a flow rate of 0.05 g / min using a liquid mass flow controller (LMFC) at room temperature. The Si2Cl6 vaporized to the vapor phase in the evaporator was introduced into the deposition chamber for 1 second, and then argon gas was supplied at 5000 sccm for 2 seconds to perform argon purging. The pressure inside the reaction chamber was controlled at 2.5 Torr.

[0221] Next, 1000 sccm of ammonia as a reactive gas was introduced into the reaction chamber for 3 seconds, and then argon purging was performed for 3 seconds. At this time, the substrate on which the metal thin film was to be formed was heated to 460°C. This process was repeated 200 to 400 times to form a SiN thin film (corresponding to a SixNy thin film (x and y are integers from 0.5 to 4.5)) which is a self-limiting atomic layer with a thickness of 10 nm.

[0222] To confirm the etching rate, the SiN thin film was immersed in the etching solution for 60 seconds using LAL500 etching solution, and the reduced film thickness was measured by ellipsometry to calculate the etching rate.

[0223]

[0224] Example 2

[0225] A SiN thin film, which is a self-limiting atomic layer, was formed in the same manner as in Example 1, except that tert-butyl bromide was used as the shielding compound.

[0226] To confirm the etching rate, the SiN thin film was immersed in the etching solution for 60 seconds using LAL500 etching solution, and the reduced film thickness was measured by ellipsometry to calculate the etching rate.

[0227]

[0228] Example 3

[0229] Tert-butyl chloride was prepared as a shielding compound and Si2Cl6 as a film precursor compound.

[0230] The prepared shielding compound was placed in a canister and supplied to an evaporator heated to 120°C at a flow rate of 0.1 g / min using a liquid mass flow controller (LMFC) at room temperature. The shielding compound vaporized in the evaporator was then introduced into a deposition chamber containing a substrate for 5 to 30 seconds, after which argon gas was supplied at 1000 sccm for 30 seconds to perform an argon purge. The pressure inside the reaction chamber was controlled at 1.0 Torr.

[0231] The prepared Si2Cl6 was then placed in a separate canister and supplied to a separate evaporator heated to 150°C at a flow rate of 0.1 g / min using a liquid mass flow controller (LMFC) at room temperature. The thin film precursor compound vaporized in the evaporator was then introduced into the deposition chamber for 5 to 30 seconds, after which argon gas was supplied at 1000 sccm for 30 seconds to perform argon purging. The pressure inside the reaction chamber was controlled at 1.0 Torr.

[0232] Next, 1000 sccm of ammonia as a reactive gas was introduced into the reaction chamber for 30 seconds, and then argon purging was performed for 30 seconds. At this time, the substrate on which the metal thin film was to be formed was heated to 500 to 650°C. This process was repeated 200 to 400 times to form a SiN thin film (corresponding to a SixNy thin film (x and y are each integers of 0.5 to 4.5)) which is a self-limiting atomic layer with a thickness of 10 nm.

[0233] To confirm the etching rate, the SiN thin film was immersed in the etching solution for 60 seconds using LAL500 etching solution, and the reduced film thickness was measured by ellipsometry to calculate the etching rate.

[0234]

[0235] Example 4

[0236] 2-Chloro-2-methylbutane was prepared as a shielding compound and Si2Cl6 as a film precursor compound.

[0237] The prepared shielding compound was placed in a canister and supplied to an evaporator heated to 120°C at a flow rate of 0.1 g / min using a liquid mass flow controller (LMFC) at room temperature. The shielding compound vaporized in the evaporator was then introduced into a deposition chamber containing a substrate for 5 to 30 seconds, after which argon gas was supplied at 1000 sccm for 30 seconds to perform an argon purge. The pressure inside the reaction chamber was controlled at 1.0 Torr.

[0238] The prepared Si2Cl6 was then placed in a separate canister and supplied to a separate evaporator heated to 150°C at a flow rate of 0.1 g / min using a liquid mass flow controller (LMFC) at room temperature. The thin film precursor compound vaporized in the evaporator was then introduced into the deposition chamber for 5 to 30 seconds, after which argon gas was supplied at 1000 sccm for 30 seconds to perform argon purging. The pressure inside the reaction chamber was controlled at 1.0 Torr.

[0239] Next, 1000 sccm of ammonia as a reactive gas was introduced into the reaction chamber for 30 seconds, and then argon purging was performed for 30 seconds. At this time, the substrate on which the metal thin film was to be formed was heated to 500 to 650°C. This process was repeated 200 to 400 times to form a SiN thin film (corresponding to a SixNy thin film (x and y are integers from 0.5 to 4.5)) which is a self-limiting atomic layer with a thickness of 10 nm.

[0240] To confirm the etching rate, the SiN thin film was immersed in the etching solution for 60 seconds using LAL500 etching solution, and the reduced film thickness was measured by ellipsometry to calculate the etching rate.

[0241]

[0242] Example 5

[0243] The same steps as in Example 3 were repeated, except that tert-butyl chloride was used as the shielding compound and SiH2Cl2 was used as the film precursor compound.

[0244] To confirm the etching rate, the SiN thin film was immersed in the etching solution for 60 seconds using LAL500 etching solution, and the reduced film thickness was measured by ellipsometry to calculate the etching rate.

[0245]

[0246] Example 6

[0247] The same process as in Example 4 was repeated, except that 2-chloro-2-methylbutane was used as the shielding compound and SiH2Cl2 was used as the film precursor compound.

[0248] To confirm the etching rate, the SiN thin film was immersed in the etching solution for 60 seconds using LAL500 etching solution, and the reduced film thickness was measured by ellipsometry to calculate the etching rate.

[0249]

[0250] Comparative Example 1

[0251] A SiN thin film was formed on a substrate in the same manner as in Example 1, except that no shielding compound was used in Example 1, and therefore the step of purging unadsorbed shielding compound was omitted.

[0252]

[0253] Comparative Example 2

[0254] A SiN thin film, which is a self-limiting atomic layer, was formed in the same manner as in Example 1, except that n-pentane was used as the shielding compound in Example 1.

[0255]

[0256] Comparative Example 3

[0257] A SiN thin film, which is a self-limiting atomic layer, was formed in the same manner as in Example 1, except that cyclopentane was used as the shielding compound.

[0258]

[0259] Comparative Example 4

[0260] A SiN thin film was formed on a substrate in the same manner as in Example 3, except that no shielding compound was used in Example 3, and therefore the step of purging unadsorbed shielding compound was omitted.

[0261]

[0262] Comparative Example 5

[0263] A SiN thin film was formed on a substrate in the same manner as in Example 4, except that no shielding compound was used in Example 4, and therefore the step of purging unadsorbed shielding compound was omitted.

[0264]

[0265] Comparative Example 6

[0266] A SiN thin film was formed on a substrate in the same manner as in Example 5, except that no shielding compound was used in Example 5, and therefore the step of purging unadsorbed shielding compound was omitted.

[0267]

[0268] Comparative Example 7

[0269] A SiN thin film was formed on a substrate in the same manner as in Example 6, except that no shielding compound was used in Example 6, and therefore the step of purging unadsorbed shielding compound was omitted.

[0270]

[0271] [Experimental Example]

[0272] 1) Evaluation of deposition and reduction of deposition rate

[0273] The growth rate of the SiN thin films deposited in Examples 1 to 6 and Comparative Examples 1 to 7 was calculated by dividing the film thickness measured by an ellipsometer, which is a device capable of measuring optical properties such as film thickness and refractive index of a thin film using the polarization characteristics of light, by the number of cycles to calculate the film thickness deposited per cycle, and then calculating the reduction rate of the film growth rate. Specifically, it was calculated using the following Equation 1.

[0274] [Formula 1]

[0275] Decrease in film growth rate per cycle (%) = [(film growth rate per cycle with shielding compound - film growth rate per cycle without shielding compound) / film growth rate per cycle without shielding compound] x 100

[0276]

[0277] As a result, it was confirmed that Examples 1 to 6, which used the shielding compound according to the present invention, showed a significantly improved reduction rate in the thin film growth rate per cycle compared to Comparative Examples 1, 4, 5, 6, and 7, which did not use the shielding compound, Comparative Example 2, which used pentane, and Comparative Example 3, which used cyclopentane.

[0278]

[0279] First, comparing Example 1, which used tert-butyl iodide as a shielding compound, with Comparative Example 1, which did not, it was found that the deposition rate was 0.29 Å / cycle, which was a decrease of 20% or more compared to 0.35 Å / cycle in Comparative Example 1.

[0280]

[0281] It was also confirmed that Comparative Examples 2 and 3, which used pentane or cyclopentane instead of the shielding compound according to the present invention, also had the same deposition rate as Comparative Example 1. In this case, a decrease in the deposition rate indicates a conversion of CVD deposition characteristics to ALD deposition characteristics, and can therefore be used as an indicator of improvement in step coverage characteristics.

[0282]

[0283] Furthermore, SIMS analysis was performed to verify whether or not doping with carbon at the ppb level was possible, and the results obtained are shown in Figure 1 below.

[0284] Specifically, FIG. 1 below is a graph showing the analysis of the SiN thin films produced in Example 1 and Comparative Example 1 by SIMS.

[0285] As is clear from FIG. 1 below, it was confirmed that Cl was significantly reduced in Example 1, which corresponds to the right graph, compared to Comparative Example 1, which corresponds to the left graph.

[0286]

[0287] Furthermore, the deposition rates obtained in Examples 3 and 4, using tert-butyl chloride and 2-chloro-2-methylbutane as the shielding compounds, respectively, are compared in FIG. 2 below.

[0288] Figure 2 below is a graph showing the change in deposition rate depending on the supply time of the shielding compound of the present invention. As can be seen from Figure 2 below, when using a silicon precursor of Si2Cl6 and a shielding compound of tert-butyl chloride for 15 seconds, the deposition rate decreased by 35% (0.66 to 0.31 Å / cycle), and when using a shielding compound of 2-chloro-2-methylbutane for 15 seconds, the deposition rate decreased by 28% (0.66 to 0.38 Å / cycle).

[0289]

[0290] Next, the deposition rate at 600°C according to the injection time for each type of shielding compound using Si2Cl6 precursor is shown in Table 1 below.

[0291] Table 1 below shows the deposition evaluation results as a function of deposition temperature when utilizing SiH2Cl2 (DCS) silicon precursor.

[0292] Tert-butyl chloride was used as the shielding compound, and the injection and purging times of the shielding compound for each ALD cycle were 5 seconds and 10 seconds, respectively.

[0293] [Table 1]

[0294] As shown in Table 1 above, it was confirmed that the deposition rate was reduced by -64% and -65% at deposition temperatures of 500°C and 600°C, respectively.

[0295]

[0296] 2) Cl impurity reduction characteristics

[0297] In order to compare the impurity reduction characteristics, ie, the fixed by-product reduction characteristics, of the SiN thin films deposited in Examples 1 to 6 and Comparative Examples 1 to 7, SIMS analysis was performed, and the results are shown in Table 2 below.

[0298] Here, the Cl reduction rate (%) was calculated using the following formula 2.

[0299] [Formula 2]

[0300]

number

[0301] [Table 2]

[0302] *Reference thickness of sample thin film: 10 nm As shown in Table 2 above, Example 1, which used the shielding compound according to the present invention, showed a significant decrease in Cl intensity at deposition temperatures of 500°C and 550°C compared to Comparative Example 1, which did not use the shielding compound, or Comparative Example 2, which used pentane, demonstrating excellent impurity reduction properties.

[0303]

[0304] 3) Doping characteristics of C thin film impurities

[0305] For quantitative analysis of elements in the SiN thin films deposited in Example 3 and Comparative Example 4, quantitative analysis was carried out by X-ray photoelectron spectroscopy (XPS).

[0306] Specifically, Si2Cl6 was used as the silicon precursor, the shielding compound was injected for 15 seconds, and deposition was carried out at a temperature of 600°C.

[0307] FIG. 3 below shows a graph illustrating the results of elemental analysis by depth using Ar sputtering for the SiN thin films produced in Examples 3 and 4 and Comparative Example 4.

[0308] As is clear from Figure 3 below, no increase in C impurities was observed due to the shielding compound, regardless of the type of shielding compound. For reference, the trace amount of oxygen corresponds to contamination caused by natural oxidation due to exposure to the outside air.

[0309]

[0310] Furthermore, SIMS analysis was performed to verify whether or not doping with carbon at the ppb level was possible, and the results obtained are shown in Figure 3 below.

[0311] Specifically, Si2Cl6 was used as the silicon precursor, and ~ was used as the shielding compound, and the injection times were set to no injection, 5-second injection, 10-second injection, 15-second injection, and 20-second injection, and deposition was performed at a temperature of 600°C.

[0312] Figure 4 below shows SIMS analysis graphs of the SiN thin films fabricated in Example 3 and Comparative Example 4. As can be seen from Figure 4 below, no changes in the Si, Cl, or N contents were observed, but the number of ions corresponding to the mass of C secondary ions emitted from the specimen was confirmed to increase by about 10 times. This C doping result also affects the density of the thin film, further confirming the etching rate improvement effect.

[0313]

[0314] 4) Step covering characteristics

[0315] In Examples 3 and 4 and Comparative Example 4, the step coverage of the deposited SiN thin film was confirmed using a transmission electron microscope (TEM) using trench substrates having an aspect ratio of 23:1, and the results are shown in FIG. 5 below.

[0316] As can be seen from FIG. 5 below, it was confirmed that the step coverage characteristics were improved from 81% to 93% and 96%, respectively, by using the shielding compound according to the present invention.

[0317]

[0318] 5) Etching rate characteristics

[0319] The etching rate of each specimen in Examples 3 and 4 and Comparative Example 4 was analyzed and is shown in Table 3 below.

[0320] [Table 3]

[0321] As shown in Table 4 above, the etching rate of Comparative Example 4 was 10.2 nm / min, and it was confirmed that the etching rates of Examples 3 and 4 were improved to 8.7 nm / min and 7.8 nm / min, respectively, by applying the shielding compound injection process to improve the quality of the thin film.

Claims

1. 1. A shielding compound for silicon-based thin films, comprising: The silicon-based thin film has a film composition of SixNy (x and y are each an integer of 0.5 to 4.5), The shielding compound has the following chemical formula 1: [Chemical formula 1] 【Chemical 1】 (wherein A is carbon, The R １ , R ３ are independently an alkyl group having 1 to 6 carbon atoms, The R ２ are independently an alkyl group having 1 to 6 carbon atoms or a group of the formula BR ４ R ５ R ６ wherein B is a carbon bonded to A, and R ４ , R ５ and R ６ are independently hydrogen, an alkyl group having 1 to 6 carbon atoms, fluorine (F), chlorine (Cl), bromine (Br), or iodine (I); The X is a halogen element, and is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

1. A shielding compound for silicon-based thin films, characterized in that it is a saturated compound represented by the formula:

2. 2. The shielding compound for silicon-based thin films according to claim 1, wherein the refractive index (a) of the shielding compound is in the range of 1.38 to 1.52, and the vapor pressure (25°C, mmHg, b) divided by the refractive index (a), (b / a), is in the range of 0.003 to 0.

033.

3. The silicon-based thin film is Si ３ N ４ , Si ２ N ３ , Si ２ 2. The shielding compound for silicon-based thin films according to claim 1, characterized in that it is composed of N, SiN, or a mixture thereof.

4. 3. A shielding compound for silicon-based thin films according to claim 1 or 2, characterized in that the shielding compound provides a shielding region for the silicon-based thin film.

5. The shielding compound for a silicon-based thin film according to claim 4, wherein the shielding region for the silicon-based thin film is formed on the entire substrate or a part of the substrate on which the silicon-based thin film is formed.

6. 5. The shielding compound for silicon-based thin films according to claim 4, wherein the shielding region for silicon-based thin films does not remain in the silicon-based thin films, and the silicon-based thin films contain less than 0.01 wt % of halogen compounds.

7. 2. The shielding compound for silicon-based thin films according to claim 1, wherein the silicon-based thin films are used as diffusion barrier films, etching stop films, or charge traps.

8. The following chemical formula 1 [Chemical formula 1] 【Chemistry 2】 (wherein A is carbon, The R １ , R ３ are independently an alkyl group having 1 to 6 carbon atoms, The R ２ are independently an alkyl group having 1 to 6 carbon atoms or a group of the formula BR ４ R ５ R ６ wherein B is a carbon bonded to A, and R ４ , R ５ and R ６ are independently hydrogen, an alkyl group having 1 to 6 carbon atoms, fluorine (F), chlorine (Cl), bromine (Br), or iodine (I); The X is a halogen element, and is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

10. A method for forming a silicon-based thin film, comprising the step of injecting a saturated structure shielding compound represented by the formula: into a chamber to shield the surface of a loaded substrate.

9. 9. The method of claim 8, wherein the chamber is an atomic layer deposition (ALD) chamber or a chemical vapor deposition (CVD) chamber.

10. 9. The method for forming a silicon-based thin film according to claim 8, wherein the shielding compound is delivered into the chamber by a vapor flow control (VFC) method, a direct liquid introduction (DLI) method, or a liquid delivery system (LDS) method, and the silicon-based thin film is a silicon nitride film.

11. A semiconductor substrate manufactured by the method for forming a silicon-based thin film according to claim 8.

12. 12. The semiconductor substrate according to claim 11, wherein the silicon-based thin film has a multi-layer structure of two or three layers.

13. A semiconductor device comprising the semiconductor substrate of claim 11.

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