Silicon precursor compound, method for producing same, and method for producing silicon-containing thin film

Abstract

The present invention relates to a novel silicon precursor compound capable of preparing an excellent silicon-containing thin film, a method for preparing the same, and a method for preparing a silicon-containing thin film using the same. The silicon precursor compounds of the present invention exhibit volatility sufficient for application in all atomic layer deposition (ALD) and chemical vapor deposition (CVD) to make silicon-containing films. In particular, deposition is possible even at a high deposition rate at a high temperature, so that a silicon-containing thin film having excellent quality can be prepared.

Description

Technical Field

[0001] This invention relates to silicon precursor compounds, methods for their preparation, and methods for preparing silicon-containing thin films using said silicon precursor compounds. Background Technology

[0002] Silicon-containing thin films, such as silicon oxide, silicon nitride, silicon oxynitride, and silicon carbonitride films, are among the thin films necessary for driving microelectronic devices, including non-semiconductor (logic) and semiconductor devices.

[0003] Atomic layer deposition (ALD), or chemical vapor deposition (CVD), is widely used to prepare silicon-containing thin films. ALD involves sequentially supplying the silicon compound gas and reactant gas required for film formation. It has the advantage of being able to form silicon-containing thin films of uniform thickness, even on highly uneven surfaces. Therefore, ALD is widely used.

[0004] Chemical vapor deposition (CVD) and atomic layer deposition (ALD) differ from each other in their working mechanisms. Depending on the various methodological conditions and their physical and chemical properties, different silicon precursors are used to prepare silicon-containing thin films.

[0005] [Existing Technical Documents] (Patent Document 1) Korean Patent Application Publication No. 2011-0017404 Summary of the Invention

[0006] Technical issues One object of the present invention is to provide a novel silicon precursor compound and a method thereof that facilitates the preparation of high-quality silicon-containing thin films.

[0007] In addition, another objective is to provide a silicon-containing thin film using the aforementioned silicon precursor compound and a method for preparing the same.

[0008] Technical solution In order to achieve the above-mentioned objectives of the present invention, a silicon precursor compound is provided, characterized by being represented by the following formula 1.

[0009] [Formula 1] In Formula 1, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; A and A' are each independently NR6R7 or R8, provided that at least one of A and A' is NR6R7; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

[0010] In one embodiment, the silicon precursor compound may have an asymmetric structure represented by Formula 2 below.

[0011] [Equation 2] In Formula 2, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

[0012] In another embodiment, the silicon precursor compound may have a symmetrical structure represented by Formula 3 below.

[0013] [Formula 3] In Formula 3, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 and R4 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; and R6 and R7 are each independently methyl or ethyl.

[0014] The silicon precursor compound of the present invention is preferably at least one selected from the following compounds (1) to (25): .

[0015] To achieve another object of the present invention, a method for preparing a silicon precursor compound is provided, comprising a first step of reacting a chlorosilane derivative with any compound selected as an alkyl hydrazine compound, namely N,N-dimethylhydrazine, N,N-diethylhydrazine and 1-ethyl-1-methylhydrazine, to form a first compound; a second step of reacting the first compound with alkyllithium (alkyl-Li) to form a lithium-containing second compound; and a third step of reacting the second compound with a silane compound to prepare a silicon precursor compound represented by Formula 2.

[0016] The first compound formed in the first step is preferably a compound represented by formula 9 below. [Formula 9] In Formula 9, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R3, R5 and R8 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

[0017] In the method for preparing silicon precursor compounds of the present invention, when at least one of R2 and R4 in the silicon precursor compound represented by Formula 2 is a halogen, the method may further include a fourth step of reacting it with a metal hydride as a reducing agent.

[0018] In the method for preparing silicon precursor compounds of the present invention, the silane compounds are prepared by reacting a chlorosilane derivative with a secondary amine.

[0019] Another method of preparing silicon precursor compounds according to the present invention may include a first step of reacting a hydrocarbon hydrazine compound with an alkyl lithium (alkyl-Li) to form a lithium-containing third compound; and a second step of reacting the third compound with a silane compound to prepare a silicon precursor compound represented by Formula 3.

[0020] The third compound is preferably a compound represented by formula 11 below. [Equation 11] In Formula 11, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms.

[0021] When at least one of R2 and R4 in the silicon precursor compound represented by Formula 3 is a halogen, the method may further include a third step of reacting it with a metal hydride as a reducing agent.

[0022] To achieve another objective of the present invention, a method for preparing a silicon-containing thin film is provided, which may include forming a silicon-containing thin film using a silicon precursor compound represented by Formula 1.

[0023] In the method for preparing silicon-containing thin films of the present invention, the silicon precursor compound is preferably selected from compounds (1) to (25).

[0024] In the method for preparing silicon-containing thin films of the present invention, the silicon-containing thin films may be deposited by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0025] The silicon-containing thin film may be selected from any one of silicon oxide film (SiO2), silicon oxycarbide film (SiOC), silicon nitride film (SiN), silicon oxynitride film (SiON), silicon carbonitride film (SiCN), and silicon carbide film (SiC).

[0026] According to a specific embodiment of the method for preparing silicon-containing thin films according to the present invention, the silicon oxide film (SiO2) may be formed by atomic layer deposition. Atomic layer deposition according to a particular embodiment includes providing a substrate in a reactor; introducing a silicon precursor compound according to the present invention into the reactor; purging the reactor using a purge gas; introducing an oxygen-containing source into the reactor to react with the silicon precursor compound according to the present invention to form a silicon oxide film; and purging the reactor using a purge gas.

[0027] According to a specific embodiment, the purge gas is used to remove unconsumed reactants and reaction byproducts. Preferably, it is selected from nitrogen, helium, argon, and mixtures thereof, but is not limited thereto.

[0028] The oxygen source according to the specific implementation scheme is preferably selected from oxygen, peroxide, oxygen plasma, water vapor, water vapor plasma, hydrogen peroxide, ozone source, and mixtures thereof, but is not limited thereto. Preferably, the oxygen source may include plasma, and the plasma may be generated in situ.

[0029] Furthermore, the atomic layer deposition method according to a specific embodiment can be performed at one or more temperatures of about 500°C or lower. In this case, those skilled in the art can appropriately select the lower limit of the temperature depending on the type of oxygen source used. Preferably, the silicon oxide film can be formed at one or more temperatures between about 300°C and 450°C.

[0030] According to another specific embodiment of the method for preparing silicon-containing thin films according to the present invention, a silicon nitride (SiN) film can be formed by plasma-enhanced atomic layer deposition. The plasma-enhanced atomic layer deposition according to the specific embodiment may include providing a substrate in a reactor; introducing a silicon precursor compound according to the present invention into the reactor; purging the reactor with a purge gas; introducing a nitrogen-containing plasma source and an inert gas into the reactor to react with the silicon precursor compound according to the present invention to form a silicon nitride film; and purging the reactor with the purge gas.

[0031] According to the specific implementation scheme, the purge gas is used to remove unconsumed reactants and reaction byproducts. Preferably, it is selected from nitrogen, helium, argon, and mixtures thereof, but is not limited thereto.

[0032] The nitrogen-containing plasma source according to the specific implementation scheme is preferably selected from nitrogen plasma, a plasma mixed with nitrogen and argon (nitrogen and argon plasma), ammonia plasma, a plasma mixed with nitrogen and ammonia (nitrogen and ammonia plasma), a plasma mixed with ammonia and helium (ammonia and helium plasma), a plasma mixed with ammonia and argon (ammonia and argon plasma), a plasma mixed with ammonia and nitrogen (ammonia and nitrogen plasma), NF3 plasma, organic amine plasma, and mixtures thereof, but is not limited thereto.

[0033] Furthermore, the plasma-enhanced atomic layer deposition method according to a specific embodiment can be performed at one or more temperatures of about 400°C or lower. In this case, those skilled in the art can appropriately select the lower limit of the temperature depending on the type of nitrogen-containing plasma source used. Preferably, the silicon nitride film can be formed at one or more temperatures of about 250°C to about 400°C, more preferably at a temperature of about 350°C.

[0034] Beneficial effects of the present invention The silicon precursor compounds of this invention exhibit sufficient volatility for application in all atomic layer deposition (ALD) and chemical vapor deposition (CVD) processes to prepare silicon-containing thin films. In particular, deposition is possible even at high temperatures and high deposition rates, thereby enabling the preparation of silicon-containing thin films with excellent quality.

[0035] However, the effects of the present invention are not limited to those described above. Attached Figure Description

[0036] Figure 1 The proton nuclear magnetic resonance spectrum of the silicon precursor compound prepared according to Example 1 of the present invention is shown. 1 H-NMR).

[0037] Figure 2 The proton nuclear magnetic resonance spectrum of the silicon precursor compound prepared according to Example 2 of the present invention is shown. 1 H-NMR).

[0038] Figure 3 The proton NMR spectrum of the silicon precursor compound prepared according to Example 3 of the present invention is shown. 1 H-NMR).

[0039] Figure 4 This is a graph showing the thermogravimetric analysis (TGA) results of a silicon precursor compound prepared according to an example of the present invention.

[0040] Figure 5The figure shows the vapor pressure measurement results of the silicon precursor compounds prepared according to Examples 1, 2 and 3 of the present invention.

[0041] Figure 6 This is a diagram showing the sequence of pulses during the silicon nitride film deposition process.

[0042] Figure 7 This is a graph showing the silicon nitride film deposition rate relative to the substrate temperature.

[0043] Figure 8 This is a diagram showing the sequence of pulses during the deposition of a silicon oxide thin film.

[0044] Figure 9 This is a graph showing the silicon oxide thin film deposition rate relative to the substrate temperature.

[0045] Figure 10 This is an image of a silicon oxide thin film deposited according to the present invention, observed using a transmission electron microscope (TEM).

[0046] Figure 11 The results are from AES (Auger electron spectroscopy) analysis of the composition of the silicon oxide thin film deposited according to the present invention.

[0047] Best mode for carrying out the invention The following text describes in detail the silicon precursor compounds, their preparation methods, silicon-containing thin films using the silicon precursor compounds, and their preparation methods.

[0048] The silicon precursor compound of the present invention can be represented by the following formula 1.

[0049] [Formula 1] In Formula 1, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; A and A' are each independently NR6R7 or R8, provided that at least one of A and A' is NR6R7; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

[0050] NR6R7 in A and A' is an amino group. Preferably, it can be selected from any one of dimethylamine, ethylmethylamine, and diethylamine.

[0051] The silicon precursor compounds of the present invention may have an asymmetric or symmetric structure.

[0052] When the silicon precursor compound has an asymmetric structure, it can be represented by the following formula 2.

[0053] [Equation 2] In Formula 2, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

[0054] When the silicon precursor compound has a symmetrical structure, it can be represented by the following formula 3.

[0055] [Formula 3] In Formula 3, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 and R4 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; and R6 and R7 are each independently methyl or ethyl.

[0056] The hydrocarbon groups in Formulas 1 to 3 may each be independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, vinyl, and their isomers. Preferably, any one selected from methyl, ethyl, and vinyl may be used.

[0057] The halogen can be any one selected from chlorine (Cl), bromine (Br), iodine (I), and fluorine (F). Chlorine (Cl) is preferred.

[0058] When the silicon precursor compound of the present invention has an asymmetric structure, the silicon precursor compound can be prepared by the method shown in reaction route 1 or reaction route 2 below.

[0059] [Reaction Route 1] [Reaction Route 2] In reaction routes 1 and 2, R1 through R8 are as defined above, and MH is a metal hydride.

[0060] In this specification, the terms first compound, second compound, and third compound are used only to distinguish compounds formed in the various steps of the method for preparing silicon precursor compounds.

[0061] The method for preparing silicon precursor compounds according to reaction route 1 is carried out in sequence by a first step of reacting a chlorosilane derivative represented by formula 7 with a hydrocarbon hydrazine compound represented by formula 8 to form a first compound represented by formula 9; a second step of reacting the first compound with an alkyllithium (alkyl-Li) to form a second compound represented by formula 10; and a third step of reacting the second compound with a silane compound represented by formula 6 to prepare a silicon precursor compound represented by formula 2.

[0062] In a method for preparing silicon precursor compounds, in a first step, a triorganochlorosilane, as a chlorosilane derivative, is reacted with a hydrocarbon hydrazine compound represented by Formula 8 at a low temperature of about -20°C in a nonpolar solvent to replace Cl with an amine, followed by filtration and vacuum distillation to form a compound of Formula 9.

[0063] In the second step, the compound of formula 9 formed in the first step is reacted with alkyl lithium (alkyl-Li) at a low temperature of about -20°C in a nonpolar solvent to lithiate the compound of formula 10.

[0064] Alkyl-Li is a lithium-containing alkyl group having 1 to 10 carbon atoms. Examples include methyllithium, ethyllithium, propyllithium, butyllithium, and isobutyllithium.

[0065] In the third step, after reacting with the silane compound represented by Formula 6 to form a silicon precursor compound, the salt (LiCl) and unreacted raw materials, which are the reaction products, are removed by filtration, and vacuum distillation is performed to obtain a silicon precursor compound having an asymmetric structure represented by Formula 2.

[0066] Another method for preparing silicon precursor compounds, as shown in reaction route 2, is carried out in the same manner as reaction route 1 above, wherein when at least one of R2 and R4 in the silicon precursor compound represented by formula 2' in reaction route 2 is a halogen selected from fluorine (F), chlorine (Cl), bromine (Br) or iodine (I), a fourth step is further carried out to react it with a metal hydride (MH) as a reducing agent.

[0067] The metal hydride (MH) may be at least one selected from lithium hydride (LiH), sodium hydride (NaH), lithium borohydride (LiBH4), lithium aluminum hydride (LiAlH4), sodium aluminum hydride (NaAlH4), and sodium lithium borohydride (NaBH4). As an example, lithium hydride (LiH), as a metal hydride (MH), can be used together with tetrahydrofuran (THF) in a reduction reaction.

[0068] Preferably, the fourth step is performed when at least one of R2 and R4 in formula 2' is chlorine (Cl).

[0069] In the methods for preparing silicon precursor compounds according to reaction routes 1 and 2, the silane compound of formula 6 can be prepared as shown in reaction route 3 below. Specifically, the chlorosilane derivative represented by formula 4 is reacted with the secondary amine represented by formula 5 at a low temperature of about -20°C in a nonpolar solvent to replace Cl with the amine, followed by filtration and vacuum distillation to form the compound of formula 6.

[0070] [Reaction Route 3] In reaction route 3, R2, R4, R6, and R7 are as defined above.

[0071] The silicon precursor compound having an asymmetric structure is at least one selected from the following compounds (1) to (15): .

[0072] When the silicon precursor compound of the present invention has a symmetrical structure, the silicon precursor compound can be prepared by the method shown in reaction route 4 or reaction route 5 below.

[0073] [Reaction Route 4] [Reaction Route 5] In reaction routes 4 and 5, R1 through R7 are as defined above, and MH is a metal hydride.

[0074] The method for preparing silicon precursor compounds according to reaction route 4 is carried out in sequence by a first step of reacting a hydrocarbon hydrazine compound represented by formula 8 with an alkyl lithium (alkyl-Li) to form a third compound represented by formula 11; and a second step of reacting the third compound with a silane compound represented by formula 6 to prepare a silicon precursor compound represented by formula 3.

[0075] In the method for preparing silicon precursor compounds, in the first step, the hydrocarbon hydrazine compound of formula 8 is reacted with alkyl lithium (alkyl-Li) at a low temperature of about -20°C in a nonpolar solvent to carry out a substitution reaction of amine and Li, thereby forming the compound of formula 11.

[0076] In the second step, after reacting with the silane compound represented by Formula 6 to form a silicon precursor compound, the salt (LiCl) and unreacted raw materials, which are the reaction products, are removed by filtration, and vacuum distillation is performed to obtain a silicon precursor compound having a symmetrical structure represented by Formula 3.

[0077] Another method for preparing silicon precursor compounds, as shown in reaction route 5, is carried out in the same manner as reaction route 4 above, wherein when at least one of R2 and R4 in the silicon precursor compound represented by formula 3' in reaction route 3 is a halogen selected from fluorine (F), chlorine (Cl), bromine (Br) or iodine (I), a third step is further carried out to react it with a metal hydride (MH) as a reducing agent.

[0078] Preferably, the third step is performed when at least one of R2 and R4 in formula 3' is chlorine (Cl).

[0079] Hexane, n-pentane, etc., can be used as nonpolar solvents in reaction routes 1 to 5, but are not limited to these. Nonpolar solvents commonly used by those skilled in the art can be used.

[0080] The silicon precursor compound having a symmetrical structure is at least one selected from the following compounds (16) to (25): .

[0081] Furthermore, in the method for preparing silicon-containing thin films of the present invention, silicon-containing thin films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD) using silicon precursor compounds represented by Formula 1.

[0082] The silicon-containing thin film can be selected from any one of silicon oxide film (SiO2), silicon carbide film (SiOC), silicon nitride film (SiN), silicon oxynitride film (SiON), silicon carbonitride film (SiCN), and silicon carbide film (SiC). Specific Implementation The invention will be described in more detail below with reference to embodiments.

[0084] [Example 1] In Example 1, dimethyl(trimethylsilyl)hydrazinetrimethylsilane of compound (3) was prepared as a silicon precursor compound with an asymmetric structure.

[0085] First, to prepare the silane compound required for the silicon precursor compound, 360 g (3.13 mol) of dichloromethylsilane (CH3SiHCl2) and 4,516 g (62.59 mol) of n-pentane were charged into a 1-liter flask under an anhydrous and inert atmosphere. The temperature was maintained at approximately -20 °C, and 282 g (6.26 mol) of dimethylamine ((CH3)2NH) was slowly added and stirred for 3 hours. After stirring was complete, dimethylamine hydrochloride ((CH3)2NH2Cl) was removed by filtration, followed by solvent removal under reduced pressure and distillation to obtain 312 g (2.52 mol) of chloro(dimethylamino)methylsilane (CH3)2NCH3SiHCl (yield: 80%).

[0086] 1 H-NMR(C6D6): δ 0.23(d, 3H (-Si CH 3 )), 2.25(s, 6H (-N (CH 3 ) 2 )), 5.0(m, 1H(-Si H )) As a first step, to prepare dimethyl(trimethylsilyl)hydrazine, 190 g (1.75 mol) of trimethylchlorosilane ((CH3)3SiCl) and 3,387 g (46.94 mol) of n-pentane were charged into a 1-liter flask under an anhydrous and inert atmosphere. The temperature was maintained at approximately -20 °C, and 210 g (3.50 mol) of dimethylhydrazine ((CH3)2NNH2) was slowly added while stirring for 12 hours. After stirring was complete, dimethylhydrazine hydrochloride ((CH3)2NNH3Cl) was removed by filtration, followed by solvent removal under reduced pressure and distillation to obtain 161 g (1.22 mol) of dimethyl(trimethylsilyl)hydrazine ((CH3)2NNHSi(CH3)3) (yield: 70%).

[0087] 1 H-NMR(C6D6): δ 0.11(s, 9H (-Si( CH 3 ) 3 )), 1.72(m, 1H (- NH Si(CH3)2),2.21(s, 6H (-NN) (CH 3 ) 2 )) Next, as a second step, 76 g (0.58 mol) of dimethyl(trimethylsilyl)hydrazine ((CH3)2NNHSi(CH3)3) and 100 g (1.16 mol) of hexane were added to a 1-liter flask under an anhydrous and inert atmosphere. The temperature was maintained at approximately -20 °C, and 245 mL (1.05 mol) of 2.5 M n-butyllithium was slowly added. The reaction solution was gradually heated to room temperature and stirred at room temperature for 12 hours.

[0088] The temperature of the mixed solution was maintained at approximately -20°C. 71 g (0.58 mol) of dimethylaminomethylsilane ((CH3)2NCH3SiHCl) was slowly added while stirring at room temperature for 6 hours or longer. After stirring was complete, the lithium chloride (LiCl) salt was removed by filtration. The solvent was removed under reduced pressure and purified to obtain 101 g (yield: 80%) of dimethyltrimethylsilylhydrazinetrimethylsilane ((CH3)2NCH3SiHN(CH3)2NSi(CH3)3).

[0089] Figure 1 The proton nuclear magnetic resonance spectrum of the silicon precursor compound prepared according to Example 1 of the present invention is shown. 1 (H-NMR). As shown, the silicon precursor compound prepared in Example 1 was identified as dimethyltrimethylsilylhydrazinetrimethylsilane.

[0090] 1 H-NMR(C6D6): δ 0.21(s, 9H (-Si( CH 3 ) 3 )), 0.25(d, 3H (-SiH CH 3 ), 2.44(s,6H (-SiHCH3N (CH 3 ) 2 )), 2.51(s, 6H (-NN (CH 3 ) 2 )), 4.90(m, 1H (-Si H CH3N(CH3)2)) [Example 2] In Example 2, compound (9) dimethylsilyldimethylhydrazinetrimethylsilane was prepared as a silicon precursor compound with an asymmetric structure.

[0091] As a first step, to prepare (dimethylsilyl)dimethylhydrazine, 100 g (1.06 mol) of dimethylchlorosilane ((CH3)2SiHCl) and 100 mL of diethyl ether were charged into a 1 L flask under an anhydrous and inert atmosphere. The temperature was maintained at approximately -20 °C, and 130.2 g (2.17 mol) of dimethylhydrazine ((CH3)2NNH2) was slowly added and stirred for 12 hours. After stirring was complete, dimethylhydrazine hydrochloride ((CH3)2NNH3Cl) was removed by filtration, followed by solvent removal under reduced pressure and distillation to obtain 85 g (0.72 mol) of (dimethylsilyl)dimethylhydrazine ((CH3)2NNHSiH(CH3)2) (yield: 68%). 1 H-NMR(C6D6): δ 0.15(d, 6H (-SiH( CH 3 ) 2 )), 1.77(s, 1H (- NH SiH(CH3)2), 2.20(s, 6H (-NN) (CH 3 ) 2 )), 4.71(m, 1H (-Si H (CH3)2)) Next, as a second step, 121 g (0.41 mol) of (dimethylsilyl)dimethylhydrazine ((CH3)2NNHSiH(CH3)2) and 108 g (0.82 mol) of hexane were charged into a 1-liter flask under an anhydrous and inert atmosphere. The temperature was maintained at approximately -20°C, and 173.3 mL (0.43 mol) of 2.5 M n-butyllithium was slowly added. The reaction solution was gradually heated to room temperature and stirred at room temperature for 12 hours. The temperature of the mixed solution was maintained at approximately -20°C. 71 g (0.41 mol) of dimethylaminomethylsilane ((CH3)2NCH3SiHCl) was slowly added while stirring at room temperature for 6 hours or longer. After stirring was complete, the lithium chloride (LiCl) salt was removed by filtration. The solvent was removed under reduced pressure and purified to give 69 g (yield: 82%) of dimethylsilyldimethylhydrazyltrimethylsilane ((CH3)2NCH3SiHN(CH3)2NSiH(CH3)2).

[0092] Figure 2 The proton nuclear magnetic resonance spectrum of the silicon precursor compound prepared according to Example 2 of the present invention is shown. 1 (H-NMR). As shown, the silicon precursor compound prepared according to Example 2 of the present invention was identified as dimethylsilyldimethylhydrazinetrimethylsilane.

[0093] 1 H-NMR(C6D6): δ 0.25(m, 9H ((CH3)2N CH 3 SiHN(CH3)2NSiH (CH 3 ) 2 ), 2.46(s, 6H(-SiHCH3N) (CH 3 ) 2 ), 2.48(s, 6H (-NN) (CH 3 ) 2 ), 4.81(m, 1H (-Si H (CH3)2), 4.82(m,1H (-Si) H CH3N(CH3)2)) [Example 3] In Example 3, compound (18) bis(trimethylsilylaminodimethylhydrazine) was prepared as a silicon precursor compound with a symmetrical structure.

[0094] 100 g (1.63 mol) of dimethylhydrazine ((CH3)2NNH2) and 281 g (3.26 mol) of hexane were placed in a 1 L flask under an anhydrous and inert atmosphere. The temperature was maintained at approximately -20 °C, and 1,315 mL (3.26 mol) of 2.5 M n-butyllithium was slowly added to the flask. The reaction solution was gradually heated to room temperature and stirred at room temperature for 12 hours.

[0095] The temperature of the mixed solution was maintained at approximately -20°C. 403 g (3.26 mol) of chloro(dimethylamino)methylsilane ((CH3)2CH3NSiHCl) was slowly added while stirring at room temperature for 6 hours or longer. After stirring was complete, the lithium chloride (LiCl) salt was removed by filtration. The solvent was removed under reduced pressure and purified to give 268 g (yield: 70%) of bis(trimethylsilylamino)dimethylhydrazine ((CH3)2NSiHCH3)2NN(CH3)2.

[0096] Figure 3 The proton nuclear magnetic resonance spectrum of the silicon precursor compound prepared according to Example 3 of the present invention is shown. 1 (H-NMR). As shown, the silicon precursor compound prepared according to Example 3 of the present invention was identified as bis(trimethylsilylaminodimethylhydrazine).

[0097] 1H-NMR(C6D6): δ 0.30(s, 6H (-SiH CH 3 N(CH3)2)2), 2.50(m, 18H (( (CH 3 ) 2 NSiHCH3) 2 NN (CH 3 ) 2 )), 4.79(m, 2H ((CH3)2NSi H CH3) 2 NN-) Thermogravimetric analysis (TGA) was performed to analyze the thermal properties of the silicon precursor compounds prepared in Examples 1 to 3. The results are as follows: Figure 4 As shown.

[0098] like Figure 4 As shown, the silicon precursor compounds of Examples 1 to 3 are volatile even at temperatures of 200°C or lower, confirming their excellent ability to form silicon-containing thin films over a wide range of temperatures.

[0099] The results above indicate that all silicon precursor compounds prepared according to Examples 1 to 3 exhibit sufficient volatility for application in all atomic layer deposition (ALD) or chemical vapor deposition (CVD) processes.

[0100] To confirm that the silicon precursor compounds prepared according to Examples 1 to 3 have vapor pressures suitable for preparing silicon thin films by deposition, their vapor pressures were measured. The results are as follows: Figure 5 As shown.

[0101] like Figure 5 As shown, the silicon precursor compounds of Examples 1 to 3 all exhibited a high vapor pressure of 10 Torr at approximately 90°C.

[0102] The vapor pressure results above indicate that all silicon precursor compounds prepared according to Examples 1 to 3 exhibit high vapor pressures at low temperatures of about 90°C or lower, suggesting that they have sufficient vapor pressures for application in all atomic layer deposition (ALD) or chemical vapor deposition (CVD) processes.

[0103] To evaluate the silicon-containing thin films formed using the silicon precursor compound prepared according to the present invention, a silicon nitride thin film was formed on a silicon substrate by atomic layer deposition (ALD) using the silicon precursor compound bis(trimethylsilylaminodimethylhydrazine) of Example 3. In this process, an ALD reactor was used, employing dual spray nozzles to supply the silicon precursor compound and the reaction gas separately in the vertical direction.

[0104] Table 1 below and Figure 6The specific conditions for depositing silicon nitride thin films are shown.

[0105] [Table 1]

[0106] The thickness of the thin film deposited using the above method was confirmed by an ellipticity meter. See Table 2 below. Figure 7 The results of the analysis of the specific silicon nitride thin film properties are shown.

[0107] [Table 2]

[0108] As shown in Table 2, the N / Si composition ratio at a substrate temperature of 350°C indicates the formation of a high-purity silicon-containing thin film. Furthermore, Figure 7 This is a graph showing the deposition rate of the silicon nitride film relative to the substrate temperature. (See figure.) Figure 7 As shown, the deposition rates are similar under conditions ranging from 250°C to 400°C.

[0109] As another embodiment, to evaluate the silicon oxide film (SiO2) formed using the silicon precursor compound prepared according to the present invention, a silicon oxide film was formed on a silicon substrate by atomic layer deposition (ALD) using the silicon precursor compound bis(trimethylsilylaminodimethylhydrazine) of Example 3. In this process, an ALD reactor was used, employing dual spray heads to supply the silicon precursor compound and the reaction gas separately in the vertical direction.

[0110] In this specification, SiN and SiO2 are used as representative silicon-containing thin films for preparation and description, but the process is not limited to these. Silicon thin films known in the art, such as SiN, SiO2, SiON, SiCN, and SiC, can be formed.

[0111] Table 3 below and Figure 8 The specific conditions for depositing silicon oxide thin films are shown.

[0112] [Table 3]

[0113] The composition of the silicon oxide films deposited in the above manner was analyzed by X-ray photoelectron spectroscopy, and the step coverage was analyzed by transmission electron microscopy (TEM). (Table 3 and...) Figure 9 The results of the analysis of the specific silicon oxide film properties are shown.

[0114] [Table 4]

[0115] As shown in Table 4, the silicon oxide film formed using the silicon precursor compound of Example 3 has a film thickness of 120 Å. The O / Si composition ratio indicates that a high-purity silicon-containing film was formed.

[0116] Figure 9 This is a graph showing the silicon oxide film deposition rate relative to the substrate temperature. (See figure.) Figure 9 As shown, the deposition rates are similar in the temperature range of 300℃ to 450℃.

[0117] Figure 10 This is an image of a silicon oxide film deposited at a substrate temperature of 400°C, observed using transmission electron microscopy (TEM). Figure 10 As shown, a silicon oxide film was uniformly formed with a thickness of 120 Å.

[0118] Figure 11 The results are from AES (Auger electron spectroscopy) analysis of the composition of a silicon oxide film deposited at a substrate temperature of 400°C.

[0119] As described above, the silicon precursor compound prepared according to the present invention can form a high-purity, high-quality silicon oxide film at a high deposition rate.

[0120] The above embodiments are only used to describe preferred embodiments of the present invention. The scope of the present invention is not limited to the described embodiments. Within the technical concept and scope of the claims of the present invention, those skilled in the art can make various changes, modifications, or substitutions. It should be understood that these embodiments fall within the scope of the present invention.

Claims

1. Silicon precursor compounds represented by Formula 1: [Formula 1] In Formula 1, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; A and A' are each independently NR6R7 or R8, provided that at least one of A and A' is NR6R7; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

2. The silicon precursor compound according to claim 1, wherein the silicon precursor compound has an asymmetric structure represented by formula 2: [Equation 2] In Formula 2, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

3. The silicon precursor compound according to claim 1, wherein the silicon precursor compound has a symmetrical structure represented by formula 3: [Formula 3] In Formula 3, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 and R4 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; and R6 and R7 are each independently methyl or ethyl.

4. The silicon precursor compound according to claim 1, wherein the silicon precursor compound is at least one selected from compounds (1) to (25): 。 5. A method for preparing a silicon precursor compound, comprising: The first step of reacting a chlorosilane derivative with a hydrocarbon hydrazine compound to form the first compound; The second step involves reacting the first compound with alkyl lithium (alkyl-Li) to form a lithium-containing second compound; as well as The third step involves reacting the second compound with a silane compound to prepare the silicon precursor compound represented by Formula 2 below: [Equation 2] In Formula 2, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

6. The method for preparing a silicon precursor compound according to claim 5, wherein the first compound is a compound represented by formula 9: [Formula 9] In Formula 9, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; and R3, R5 and R8 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

7. The method for preparing silicon precursor compounds according to claim 5, wherein, When at least one of R2 and R4 in the silicon precursor compound represented by Formula 2 is a halogen, the method further includes a fourth step of reacting it with a metal hydride as a reducing agent.

8. The method for preparing silicon precursor compounds according to claim 5, wherein the silane compound is prepared by reacting a chlorosilane derivative with a secondary amine.

9. A method for preparing a silicon precursor compound, comprising: The first step of reacting a hydrocarbon hydrazine compound with an alkyl lithium (alkyl-Li) to form a lithium-containing third compound; as well as The second step involves reacting the third compound with a silane compound to prepare a silicon precursor compound represented by Formula 3: [Formula 3] In Formula 3, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 and R4 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; and R6 and R7 are each independently methyl or ethyl.

10. The method for preparing a silicon precursor compound according to claim 9, wherein the third compound is a compound represented by formula 11: [Equation 11] In Formula 11, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms.

11. The method for preparing silicon precursor compounds according to claim 9, wherein, When at least one of R2 and R4 in the silicon precursor compound represented by Formula 3 is a halogen, the method further includes a third step of reacting it with a metal hydride as a reducing agent.

12. The method for preparing silicon precursor compounds according to claim 9, wherein the silane compound is prepared by reacting a chlorosilane derivative with a secondary amine.

13. A method for preparing a silicon-containing thin film, comprising forming the silicon-containing thin film using a silicon precursor compound represented by Formula 1: [Formula 1] In Formula 1, R1 is each independently a straight-chain or branched, saturated or unsaturated hydrocarbon group or its isomer having 1 to 4 carbon atoms; R2 to R5 are each independently hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms; A and A' are each independently NR6R7 or R8, provided that at least one of A and A' is NR6R7; R6 and R7 are each independently methyl or ethyl; and R8 is hydrogen (H), halogen, or a straight-chain or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms.

14. The method for preparing a silicon-containing thin film according to claim 13, wherein the silicon precursor compound is at least one selected from compounds (1) to (25): 。 15. The method for preparing a silicon-containing thin film according to claim 13, wherein the silicon-containing thin film is deposited by chemical vapor deposition or atomic layer deposition.

16. The method for preparing a silicon-containing thin film according to claim 13, wherein the silicon-containing thin film is selected from any one of silicon oxide film (SiO2), silicon carbide film (SiOC), silicon nitride film (SiN), silicon oxynitride film (SiON), silicon carbonitride film (SiCN), and silicon carbide film (SiC).

17. The method for preparing a silicon-containing thin film according to claim 15, wherein the silicon-containing thin film is a silicon oxide film (SiO2). The silicon oxide film is deposited by atomic layer deposition, and the atomic layer deposition includes providing a substrate in a reactor; and introducing the silicon precursor compound into the reactor; The reactor is purged with a purge gas; an oxygen source is introduced into the reactor to react with the silicon precursor compound to form a silicon oxide film; And the reactor is purged using the purge gas.

18. The method for preparing a silicon-containing thin film according to claim 17, wherein the purge gas is selected from nitrogen, helium, argon, and mixtures thereof, and The oxygen source is selected from oxygen, peroxide, oxygen plasma, water vapor, water vapor plasma, hydrogen peroxide, ozone source and mixtures thereof.

19. The method for preparing a silicon-containing thin film according to claim 17, wherein the oxygen source comprises plasma.

20. The method for preparing a silicon-containing thin film according to claim 19, wherein the plasma is generated in situ.

21. The method for preparing a silicon-containing thin film according to claim 17, wherein the atomic layer deposition is performed at one or more temperatures of 500°C or lower.

22. The method for preparing a silicon-containing thin film according to claim 15, wherein the silicon-containing thin film is a silicon nitride film (SiN). The silicon nitride film was deposited via plasma-enhanced atomic layer deposition, and The plasma-enhanced atomic layer deposition includes providing a substrate in a reactor; introducing the silicon precursor compound into the reactor; purging the reactor with a purge gas; introducing a nitrogen-containing plasma source and an inert gas into the reactor to react with the silicon precursor compound to form a silicon nitride film; and purging the reactor with the purge gas.

23. The method for preparing silicon-containing thin films according to claim 22, wherein the nitrogen-containing plasma source is selected from nitrogen plasma, a plasma containing nitrogen and argon, ammonia plasma, a plasma containing nitrogen and ammonia, a plasma containing ammonia and helium, a plasma containing ammonia and argon, a plasma containing ammonia and nitrogen, NF3 plasma, organic amine plasma, and mixtures thereof.

24. The method for preparing a silicon-containing thin film according to claim 22, wherein the plasma-enhanced atomic layer deposition is performed at one or more temperatures of 400°C or lower.

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