Patent Application
20250230176
The present invention relates to a silicon precursor compound in an asymmetric structure containing an alkoxide, to a method for preparing the same, and to a method for preparing a silicon-containing thin film using the silicon precursor compound.
Silicon-containing thin films are used as semiconductor substrates, diffusion masks, anti-oxidation films, and dielectric films in the semiconductor technologies such as microelectronic devices such as RAM (memory and logic chips), flat panel displays including thin film transistors (TFT), and solar energy.
In particular, in accordance with the high integration of semiconductor devices, silicon-containing thin films having various performances are required. As the aspect ratio increases with the high integration of semiconductor devices, there has been a problem in that the deposition of a silicon-containing thin film using a conventional precursor does not meet the required performance.
It is difficult to achieve excellent step coverage and thickness control for highly integrated semiconductor devices with thin film deposition using conventional precursors. There is also a problem in that impurities are contained in the thin film.
Accordingly, there has been a demand for the development of various silicon precursor compounds depending on physical and chemical properties as a silicon precursor necessary for forming a high-quality silicon-containing film.
An object of the present invention is to provide a novel silicon precursor compound in an asymmetric structure containing an alkoxide capable of preparing a silicon-containing thin film with excellent quality and a method for preparing the same.
In addition, another object is to provide a method for preparing a silicon-containing thin film using the novel silicon precursor compound in an asymmetric structure containing an alkoxide.
The silicon precursor compound of the present invention for accomplishing the above object is characterized in that it is represented by the following Formula 1.
In Formula 1, n is 1 or 2; R1 is any one selected from a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, an isomer thereof, and NR7R8; R2 and R3 are each any one selected from hydrogen (H), chlorine (Cl), methyl (Me), methoxy (MeO), ethoxy (EtO), n-propoxy, isopropoxy (isoPrO), n-butoxy, isobutoxy (isoBuO), sec-butoxy (secBuO), tert-butoxy (tertBuO), and NR7R8; R4 is a linear or branched, saturated or unsaturated hydrocarbon group or an isomer thereof; R5 is any one selected from methyl (Me), ethyl (Et), iso-propyl (isoPr), SiMe3, SiHMe2, SiH2Me, SiH3, SiHClMe, SiHCl2, SiMe2CH2CH3, SiMe2CH═CH2, and SiHMeCH═CH2; and R7 and R8 in NR7R8 are each any one selected from methyl (Me), ethyl (Et), and iso-propyl (isoPr). In the silicon precursor compound of the present invention, R4 and R5 may be different from each other, preferably, R4 and R5 are different from each other.
The silicon precursor compound of the present invention is preferably selected from the group consisting of the following compounds (1) to (56).
The method for preparing a silicon precursor compound of the present invention for accomplishing another object may comprise reacting an alkoxide compound with a secondary amine or reacting an alkoxide compound with an alkylaminosilane to prepare a silicon precursor compound represented by Formula 1.
The alkoxide compound is preferably a compound represented by the following Formula 4.
In Formula 4, n is 1 or 2; R1 is any one selected from a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, an isomer thereof, and NR7R8; R2 and R3 are each any one selected from hydrogen (H), chlorine (Cl), methyl (Me), methoxy (MeO), ethoxy (EtO), n-propoxy, isopropoxy (isoPrO), n-butoxy, isobutoxy (isoBuO), sec-butoxy (secBuO), tert-butoxy (tertBuO), and NR7R8. R7 and R8 in NR7R8 are each any one selected from methyl (Me), ethyl (Et), and iso-propyl (isoPr).
In the method for preparing a silicon precursor compound, the reaction of the alkoxide compound with the secondary amine may prepare a silicon precursor compound represented by the following Formula 8.
In Formula 8, R1 is any one selected from a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, an isomer thereof, and NR7R8; R3 is any one selected from hydrogen (H), chlorine (Cl), methyl (Me), methoxy (MeO), ethoxy (EtO), n-propoxy, isopropoxy (isoPrO), n-butoxy, isobutoxy (isoBuO), sec-butoxy (secBuO), tert-butoxy (tertBuO), and NR7R8; R4 is a linear or branched, saturated or unsaturated hydrocarbon group or an isomer thereof; R5 is any one selected from methyl (Me), ethyl (Et), iso-propyl (isoPr), SiMe3, SiHMe2, SiH2Me, SiH3, SiHClMe, SiHCl2, SiMe2CH2CH3, SiMe2CH═CH2, and SiHMeCH═CH2; and R7 and R8 in NR7R8 are each any one selected from methyl (Me), ethyl (Et), and iso-propyl (isoPr).
In the method for preparing a silicon precursor compound, the reaction of the alkoxide compound with the alkylaminosilane may prepare a silicon precursor compound represented by the following Formula 15 or Formula 18.
In Formula 15 or Formula 18, R1 is any one selected from a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, an isomer thereof, and NR7R8; R2, R2′, R3, and R3′ are each any one selected from hydrogen (H), chlorine (Cl), methyl (Me), methoxy (MeO), ethoxy (EtO), n-propoxy, isopropoxy (isoPrO), n-butoxy, isobutoxy (isoBuO), sec-butoxy (sec BuO), tert-butoxy (tertBuO), and NR7R8; R0 is a linear or branched, saturated or unsaturated hydrocarbon group or an isomer thereof; R9, R10, and R11 are each any one selected from hydrogen (H), chlorine (Cl), a methyl group (Me), an ethyl group (CH2CH3), and a vinyl group (CH═CH2); and R7 and R8 in NR7R8 are each any one selected from methyl (Me), ethyl (Et), and iso-propyl (isoPr).
The silicon precursor compound of Formula 1 prepared according to the method for preparing a silicon precursor compound of the present invention is at least one selected from compounds (1) to (56).
In order to accomplish another object, the method for preparing a silicon-containing thin film according to the present invention may form a silicon-containing thin film using the silicon precursor compound represented by Formula 1.
In the method for preparing a silicon-containing thin film according to the present invention, the silicon precursor compound is at least one selected from compounds (1) to (56).
In the method for preparing a silicon-containing thin film according to the present invention, the silicon-containing thin film may be deposited by chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or atomic layer deposition (ALD).
The silicon precursor compound of the present invention exhibits sufficient volatility to be applied to all of atomic layer deposition (ALD), plasma-enhanced chemical vapor deposition (PECVD), and chemical vapor deposition (CVD) for preparing silicon-containing thin films. In particular, deposition is possible even at high temperatures in a high deposition rate, whereby a silicon-containing thin film with excellent quality can be prepared.
However, the effects of the present invention are not limited to those mentioned above.
Hereinafter, the silicon precursor compound and the method for preparing the same according to the present invention will be described in detail.
In the present specification, the term “about” is intended to cover ±5% of the number defined.
The silicon precursor compound in an asymmetric structure containing an alkoxide according to the present invention may be represented by the following Formula 1.
In Formula 1, n is 1 or 2; R1 is any one selected from a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, an isomer thereof, and NR7R8; R2 and R3 are each any one selected from hydrogen (H), chlorine (Cl), methyl (Me), methoxy (MeO), ethoxy (EtO), n-propoxy, isopropoxy (isoPrO), n-butoxy, isobutoxy (isoBuO), sec-butoxy (secBuO) tert-butoxy (tertBuO), and NR7R8; R4 is a linear or branched, saturated or unsaturated hydrocarbon group (e.g., having 1 to 6 carbon atoms) or an isomer thereof; and R5 is any one selected from methyl (Me), ethyl (Et), iso-propyl ('s° Pr), SiMe3, SiHMe2, SiH2Me, SiH3, SiHClMe, SiHCl2, SiMe2CH2CH3, SiMe2CH═CH2, and SiHMeCH═CH2.
R7 and R8 in NR7R8 are each any one selected from methyl (Me), ethyl (Et), and iso-propyl (isoPr).
The hydrocarbon groups in R1 and R4 may each independently be any one selected from the group consisting of a methyl group (Me), an ethyl group (Et), an n-propyl group (Pr), an iso-propyl group (isoPr), an n-butyl group (Bu), a sec-butyl group (secBu), an iso-butyl group (isoBu), a tert-butyl group (tertBu), and isomers thereof.
In the present invention, R4 and R5 may be different from each other, preferably, R4 and R5 are different from each other.
The alkoxide in the present invention is a compound in which hydrogen (H) in a hydroxyl group (OH) of an alcohol is substituted with a metal. It is a silicon alkoxide in which silicon (Si) is substituted as a metal.
The silicon precursor compound of the present invention may be prepared by a method as shown in Reaction Scheme 1 and Reaction Scheme 2 below.
In the method for preparing a silicon precursor according to Reaction Scheme 1, an alkoxide compound is reacted with a secondary amine to prepare a silicon precursor compound represented by Formula 1. It is carried out by a first step of reacting a chlorosilane compound represented by Formula 2 with an alcohol compound represented by Formula 3 to form an alkoxide compound; and a second step of reacting the alkoxide compound with a secondary amine represented by Formula 5 to prepare a silicon precursor compound represented by Formula 1.
As a specific example of Reaction Scheme 1, when n is 1, and R2 is hydrogen (H), a silicon compound represented by Formula 8 can be prepared as shown in Reaction Scheme 2 below.
In Reaction Schemes 1 and 2, n is 1 or 2; R1 is any one selected from a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, an isomer thereof, and NR7R8; R2 and R3 are each any one selected from hydrogen (H), chlorine (Cl), methyl (Me), methoxy (MeO), ethoxy (EtO), n-propoxy, isopropoxy (isoPrO), n-butoxy, isobutoxy (isoBuO), sec-butoxy (secBuO), tert-butoxy (tertBuO), and NR7R8; R4 is a linear or branched, saturated or unsaturated hydrocarbon group (e.g., having 1 to 6 carbon atoms) or an isomer thereof; and R5 is any one selected from methyl (Me), ethyl (Et), iso-propyl (isoPr), SiMe3, SiHMe2, SiH2Me, SiH3, SiHClMe, SiHCl2, SiMe2CH2CH3, SiMe2CH═CH2, and SiHMeCH═CH2.
In the method for preparing a silicon precursor according to Reaction Schemes 1 and 2, in the first step, a chlorosilane compound is reacted with an alcohol compound at a low temperature of about −40° C. in a non-polar solvent to perform a substitution reaction of Cl and an alcohol compound, followed by filtration and distillation under a reduced pressure to form an alkoxide compound.
In the second step, the alkoxide compound formed in the first step is reacted with a secondary amine represented by Formula 5, followed by the removal of a product salt and unreacted materials of the reactants through filtration and distillation under a reduced pressure to obtain a silicon precursor compound.
The silicon precursor compound of the present invention may be prepared by another method as shown in Reaction Scheme 3 and Reaction Scheme 4 below.
In the method for preparing a silicon precursor according to Reaction Schemes 3 and 4, an alkoxide compound is reacted with an alkylaminosilane to prepare a silicon precursor compound.
As shown in Reaction Scheme 4, it is carried out by a first step of reacting a chlorosilane compound represented by Formula 11 with a primary amine represented by Formula 12 to form an alkylaminosilane represented by Formula 13; a second step of reacting the alkylaminosilane with an alkyl-lithium (Alkyl-Li) to form an alkylaminosilane containing lithium as represented by Formula 14; and a third step of reacting the compound of Formula 14 with an alkoxide compound of Formula 10 to prepare a silicon precursor compound represented by Formula 15.
The alkoxide compound represented by Formula 10 may be formed by reacting a chlorosilane compound represented by Formula 9 with an alcohol compound represented by Formula 3 as shown in Reaction Scheme 3.
Another method for preparing a silicon precursor compound is carried out in the same manner as in Reaction Scheme 4, except that the alkoxide compound used in Reaction Scheme 4 is a compound of Formula 17 prepared according to Reaction Scheme 5 below to prepare a silicon precursor compound of Formula 18 as shown in Reaction Scheme 6.
In Reaction Schemes 3 to 6, R1 is any one selected from a linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, an isomer thereof, and NR7R8; R2, R2′, R3, and R3′ are each any one selected from hydrogen (H), chlorine (Cl), methyl (Me), methoxy (MeO), ethoxy (EtO), n-propoxy, isopropoxy (isoPrO), n-butoxy, isobutoxy (iso BuO), sec-butoxy (sec BuO), tert-butoxy (tertBuO), and NR7R8; R0 is a linear or branched, saturated or unsaturated hydrocarbon group (e.g., having 1 to 6 carbon atoms) or an isomer thereof; and R9, R10, and R11 are each any one selected from hydrogen (H), chlorine (Cl), a methyl group (Me), an ethyl group (CH2CH3), and a vinyl group (CH═CH2).
In the method for preparing a silicon precursor according to Reaction Schemes 4 and 6, in the first step, a triorganochlorosilane as a chlorosilane compound is reacted with a primary amine at a low temperature of about −40° C. in a non-polar solvent to perform a substitution reaction of Cl and an amine, followed by filtration and distillation under a reduced pressure to form an alkylaminosilane of Formula 13.
In the second step, the alkylaminosilane formed in the first step is reacted with an alkyl-lithium (alkyl-Li) at a low temperature of about −40° C. in a non-polar solvent to perform a Li substitution reaction to form a compound of Formula 14.
Here, the alkyl-Li is lithium containing an alkyl group having 1 to 10 carbon atoms. Examples thereof include methyl lithium, ethyl lithium, propyl lithium, butyl lithium, and isobutyl lithium.
In the third step, after a reaction with the alkoxide compound represented by Formula 10 or 17, the salt (LiCl) as a product of the reaction and unreacted materials are removed through filtration, and distillation under a reduced pressure is performed to obtain a silicon precursor compound.
As the non-polar solvent used in Reaction Schemes 1 to 6, hexane, n-pentane, or the like may be used, but it is not limited thereto. A non-polar solvent commonly used by a person of ordinary skill in the art can be used.
The silicon precursor compound of the present invention may be selected from the group consisting of the following compounds (1) to (56).
In addition, according to the method for preparing a silicon-containing thin film of the present invention, a silicon-containing thin film can be formed using the silicon precursor compound represented by Formula 1 by chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or atomic layer deposition (ALD) well known to a person of ordinary skill in the art. The silicon-containing thin film according to the present invention may be any one selected from the group consisting of a silicon oxide (SiO2) film, a silicon oxycarbide (SiOC) film, a silicon nitride (SiN) film, a silicon oxynitride (SiON) film, a silicon carbonitride (SiCN) film, a silicon oxycarbonitride (SiOCN) film, and silicon carbonized (SiC) film, but it is not limited thereto. The silicon-containing thin film according to the present invention is preferably a silicon oxide film (SiO2).
The silicon oxide film according to the present invention is preferably deposited by atomic layer deposition. The atomic layer deposition comprises providing a substrate to a reactor; feeding a silicon precursor compound to the reactor; purging the reactor with a purge gas; feeding an oxygen source to the reactor to react with the silicon precursor compound to form a silicon oxide film; and purging the reactor with a purge gas. The purge gas is selected from the group consisting of nitrogen, helium, argon, and mixtures thereof, but it is not limited thereto. The oxygen source is selected from the group consisting of oxygen, peroxide, oxygen plasma, water vapor, water vapor plasma, hydrogen peroxide, ozone source, and mixtures thereof, but it is not limited thereto. The oxygen source is preferably ozone (O3).
The step of forming the silicon oxide film may be carried out at a temperature of about 200° C. to about 600° C. and is preferably carried out at a temperature of about 400° C.
Hereinafter, the present invention will be described in detail with reference to examples.
In Example 1, diisopropyldimethoxysilaneamine of compound (1) was prepared as a silicon precursor compound.
In the first step, dichlorodiisopropylsilanamine (1,1-dichloro-N,N-diisopropylsilanamine) was prepared. A 5-liter flask in an anhydrous and inert atmosphere was charged with 200 g (1.48 moles) of trichlorosilane (HSiCl3) and 1,279 g (17.72 moles) of n-pentane. While the temperature was maintained at −40° C., 306 g (3.03 moles) of diisopropylamine (((CH3)2CH)2NH) was slowly added, followed by stirring for 3 hours. Upon completion of the stirring, the diisopropylamine hydrochloride salt (((CH3)2CH)2NH2Cl) was removed through filtration, and 264.5 g (1.48 moles) of dichlorodiisopropylsilaneamine (((CH3)2CH)2NSiHCl2) (yield: 89%) was obtained through purification under a reduced pressure.
1H-NMR (C6D6): δ 0.92(d, 12H(N(CH(CH3)2)2)), 3.09(m, 2H(N(CH(CH3)2)2)), 5.65 (s, 1H(—SiH))
In the second step, a 5-liter flask in an anhydrous and inert atmosphere was charged with 161 g (1.11 moles) of dichlorodiisopropylsilaneamine (((CH3)2CH)2NSiHCl2) prepared in the first step and 1,430 g (19.82 moles) of n-pentane. While the temperature was maintained at −40° C., 274 g (2.71 moles) of triethylamine (N(CH2CH3)3) was slowly added, and 109 ml (2.71 moles) of methanol (CH3OH) was slowly added. The temperature was then gradually raised to room temperature, followed by stirring for 3 hours. Upon completion of the stirring, the triethylamine salt (N(CH2CH3)3HCl) was removed through filtration, followed by removing the solvent under a reduced pressure and distillation to obtain 156.8 g (1.32 moles) of diisopropyldimethoxysilaneamine (((CH3)2CH)2NSiH(OCH3)2) (yield: 62.3%) as a silicon precursor compound.
1H-NMR (C6D6): δ 1.11(d, 12H(N(CH(CH3)2)2)), 3.18(m, 2H(N(CH(CH3)2)2)), 3.40 (s, 6H(OCH3)2), 4.63 (s, 1H(—SiH))
In Example 2, ethoxymethylsilylisopropyltrimethylsilanamine of compound (2) was prepared as a silicon precursor compound.
First, chloro(ethoxy)(methyl)silane as a silane compound needed to prepare a silicon precursor compound was prepared. A 1-liter flask in an anhydrous and inert atmosphere was charged with 250 g (2.17 moles) of dichloromethylsilane (CH3SiHCl2) and 1,568 g (21.73 mol) of n-pentane. While the temperature was maintained at −40° C., 230 g (2.28 moles) of triethylamine (N(CH2CH3)3) was slowly added, and, in one hour, ethanol (CH3CH2OH) was slowly added. The temperature of the reaction solution was then gradually raised to room temperature, followed by stirring for 3 hours. Upon completion of the stirring, the triethylamine hydrochloride salt (N(CH2CH3)3HCl) was removed through filtration, and 185 g (1.49 moles) of chloroethoxymethylsilane (CH3CH2OSiHMeCl) (yield: 69%) was obtained through purification under a reduced pressure.
1H-NMR (C6D6): δ 0.22(d, 3H(—SiCH3)), 1.01(t, 3H(—OCH2CH3)), 3.59(m, 2H(—OCH2CH3)), 5.14(m, 1H(—SiH))
In the first step of Example 2, isopropylaminotrimethylsilazane was prepared. A 1-liter flask in an anhydrous and inert atmosphere was charged with 220 g (2.03 moles) of chlorotrimethylsilane ((CH3)3SiCl) and 2,190 g (30 moles) of n-pentane. While the temperature was maintained at −40° C., 251 g (4.25 moles) of isopropylamine ((CH3)2CHNH2) was slowly added, followed by stirring for 3 hours. Upon completion of the stirring, the isopropylamine hydrochloride salt ((CH3)2CHNH3Cl) was removed through filtration, followed by removing the solvent under a reduced pressure and distillation to obtain 205 g (1.5 moles) of isopropylaminotrimethylsilazane ((CH3)2CHNSiH(CH3)3) (yield: 77%).
1H-NMR (C6D6): δ 0.06(s, 9H(SiCH3)3), 0.96(d, 6H(NCH(CH3)2)), 2.92(m, 1H(NCH(CH3)2))
In the second step of Example 2, a 1-liter flask in an anhydrous and inert atmosphere was charged with 200 g (1.38 moles) of isopropylaminotrimethylsilazane ((CH3)2CHNSiH(CH3)3) prepared in the first step and 1,186 g (13.76 moles) of hexane. While the temperature was maintained at −40° C., 402 ml (1.45 moles) of 2.5 M n-butyllithium (n-BuLi) was slowly added. The temperature was then gradually raised to room temperature, followed by stirring for 12 hours.
Next, in the third step of Example 2, while the mixed solution in the second step was maintained at −20° C., 171.5 g (1.38 moles) of chloroethoxymethylsilane (CH3CH2OSiHMeCl) was slowly added thereto, followed by stirring for 6 hours or longer. Upon completion of the stirring, the lithium chloride (LiCl) salt was removed through filtration. The solvent in the filtrate was removed under a reduced pressure, followed by distillation to obtain 181 g (1.38 moles) of ethoxymethylsilylisopropyltrimethylsilanamine (CH3CH2OSiHMeNiPrSiMe3) (yield: 60%) as a silicon precursor compound.
1H-NMR (C6D6): δ 0.18(s, 9H(—Si(CH3)3)), 0.28(d, 3H(—SiHCH3)), 1.15(t, 3H(—O(CH2CH3))), 1.17(m, 6H(—SiNCH(CH3)2)), 3.20(m, 1H(—NCH(CH3)2)), 3.65(m, 2H(—O(CH2CH3))), 4.95(m, 1H(—SiH))
In Example 3, dimethylsilylethoxyisopropylmethylsilanamine of compound (3) was prepared as a silicon precursor compound.
In the first step of Example 3, isopropyldimethylsilaneamine was prepared. A 1-liter flask in an anhydrous and inert atmosphere was charged with 100 g (1.06 moles) of chlorodimethylsilane ((CH3)2SiHCl) and 1,143 g (15.0 moles) of n-pentane. While the temperature was maintained at −40° C., 128 g (2.17 moles) of isopropylamine ((CH3)2CHNH2) was slowly added, followed by stirring for 3 hours. Upon completion of the stirring, the isopropylamine hydrochloride salt ((CH3)2CHNH3Cl) was removed through filtration, followed by purification under a reduced pressure to obtain 101 g (1.06 moles) of isopropyldimethylsilaneamine ((CH3)2CHNHSiH(CH3)2) (yield: 82%).
1H-NMR (C6D6): δ 0.08(s, 6H(Si(CH3)2)), 0.96(d, 6H(NCH(CH3)2)), 2.95(m, 1H (NCH(CH3)2)), 4.71(m, 1H(—SiH))
In the second step of Example 3, a 1-liter flask in an anhydrous and inert atmosphere was charged with 100 g (0.85 mole) of isopropyldimethylsilaneamine ((CH3)2CHNHSiH(CH3)2) prepared in the first step and 367 g (5.0 moles) of hexane. While the temperature was maintained at −40° C., 257 ml (0.90 mole) of 2.5 M n-butyllithium (n-BuLi) was slowly added. The temperature was then gradually raised to room temperature, followed by stirring for 12 hours.
Next, in the third step of Example 3, while the mixed solution in the second step was maintained at −20° C., 177 g (0.85 mole) of chloroethoxymethylsilane (CH3CH2OSiHMeCl) was slowly added thereto, followed by stirring for 6 hours or longer. Upon completion of the stirring, the lithium chloride (LiCl) salt was removed through filtration. The solvent in the filtrate was removed under a reduced pressure, followed by distillation to obtain 122 g of dimethylsilylethoxyisopropylmethylsilanamine (CH3CH2OSiHMeNiPrSiHMe2) (yield: 70%) as a silicon precursor compound.
1H-NMR (C6D6): δ 0.20(m, 6H(—SiH(CH3)2)), 1.14(t, 3H(—O(CH2CH3)), 1.17(m, 6H(—SiNCH2(CH3)2)), 3.27(m, 1H(NCH(CH3)2)), 3.65(m, 2H(—O(CH2CH3))), 4.75(m, 1H(—SiH(CH3)2)), 4.88(m, 1H(—SiH(CH3)2))
In Example 4, diethylaminooxymethylsilylisopropyltrimethylsilanamine of compound (25) was prepared as a silicon precursor compound.
In the first step of Example 4, isopropylaminotrimethylsilazane was prepared in the same manner as in Example 2.
In the second step of Example 4, chloro(methyl)silyl)diethylhydroxylamine was prepared. A 1-liter flask in an anhydrous and inert atmosphere was charged with 100 g (0.86 mole) of dichloromethylsilane (CH3SiHCl2) and 1,140 g (13.04 moles) of n-pentane. While the temperature was maintained at −40° C., 92.4 g (0.92 mole) of triethylamine ((CH3CH2)3N) was added, and, in one hour, 81.4 g (0.92 mole) of diethylhydroxyamine ((CH3CH2)2NOH) was slowly added. The temperature was then raised to room temperature, followed by stirring for 3 hours. Upon completion of the stirring, the triethylamine hydrochloride salt ((CH3CH2)3NHCl) was removed through filtration, followed by removing the solvent under a reduced pressure and distillation to obtain 132 g (0.78 mole) of chloro(methyl)silyl)diethylhydroxylamine ((CH3CH2)2NOSiHMeCl) (yield: 90%).
1H-NMR (C6D6): δ 0.34(d, 3H(SiCH3)), 0.83(m, 6H—ON(CH2CH3)2), 2.66(m, 4H(—ON(CH2CH3)2), 5.23(m, 1H(—SiH))
In the third step of Example 4, a 1-liter flask in an anhydrous and inert atmosphere was charged with 14 g (0.12 mole) of isopropylaminotrimethylsilazane ((CH3)2CHNHSi(CH3)3) prepared in the first step and 74.2 g (0.86 mole) of hexane. While the temperature was maintained at −40° C., 52 ml (0.13 mole) of 2.5 M n-butyllithium (n-BuLi) was slowly added. The temperature was then gradually raised to room temperature, followed by stirring for 2 hours. Next, while the mixed solution was maintained at −20° C., 30 g (0.12 mole) of chloro(methyl)silyl)diethylhydroxylamine ((CH3CH2)2NOHSiCH3Cl) prepared in the second step was slowly added thereto, followed by stirring for 6 hours at room temperature. Upon completion of the stirring, the lithium chloride (LiCl) salt was removed through filtration. The solvent in the filtrate was removed under a reduced pressure, followed by purification to obtain g of diethylaminooxymethylsilylisopropyltrimethylsilanamine ((CH3CH2)2NOCH3HSiNCH(CH3)2Si(CH3)3) (yield: 62%) as a silicon precursor compound.
1H-NMR (C6D6): δ 0.12(s, 9H(—Si(CH3)3), 0.25(d, 3H(—SiHCH3)), 1.07(m, 6H(—ON(CH2CH3) 2), 1.20(m, 6H(—NCH(CH3)2)), 2.76(m, 4H(—ON(CH2CH3)2)), 3.29(m, 1H(—NCH(CH3)2)), 4.69(m, 1H(—SiH))
In Example 5, isopropylmethoxytetramethyltrimethylsilyldisilanamine of compound (35) was prepared as a silicon precursor compound.
In the first step of Example 5, chloromethoxytetramethyldisilane was prepared. A 1-liter flask in an anhydrous and inert atmosphere was charged with 193 g (1.03 moles) of dichlorotetramethyldisilane (Cl(CH3)2SiSi(CH3)2Cl) and 2,754 g (38.15 moles) of n-pentane. While the temperature was maintained at −40° C., 99 g (0.98 mole) of triethylamine (N(CH2CH3)3) was slowly added, and 31 g (0.98 mole) of methanol (HOCH3) was slowly added. The temperature was then gradually raised to room temperature, followed by stirring for 16 hours. Upon completion of the stirring, the triethylamine salt (N(CH2CH3)3HCl) was removed through filtration, followed by removing the solvent under a reduced pressure and distillation to obtain 119 g (0.65 mole) of chloromethoxytetramethyldisilane (CH3O(CH3)2SiSi(CH3)2Cl) (yield: 67%).
1H-NMR (CDCl3): δ 0.32(s, 6H(—Si(OCH3)(CH3)2)), 0.53(s, 6H(—SiCl(CH3)2)), 3.48(s, 3H(—OCH3))
In the second step of Example 5, a 1-liter flask in an anhydrous and inert atmosphere was charged with 129 g (0.89 mole) of isopropyltrimethylsilanamine ((CH3)2CHNHSi(CH3)3) and 535 g (6.20 moles) of n-hexane. While the temperature was maintained at −15° C., 372 ml (0.93 mole) of 2.5 M n-butyllithium (n-BuLi) was slowly added. The temperature was then gradually raised to room temperature, followed by stirring for 2 hours.
Next, in the third step of Example 5, while the mixed solution in the second step was maintained at −3° C., 162 g (0.89 mole) of chloromethoxytetramethyldisilane (CH3O(CH3)2SiSi(CH3)2Cl) prepared in the first step was slowly added thereto, followed by raising the temperature to room temperature and stirring for 16 hours. Upon completion of the stirring, the lithium chloride (LiCl) salt was removed through filtration. The solvent in the filtrate was removed under a reduced pressure, followed by distillation to obtain 138 g (0.48 mole) of isopropylmethoxytetramethyltrimethylsilyldisilanamine (CH3O(CH3)2SiSi(CH3)2N(CH(CH3)2)Si(CH3)3) (yield: 54%) as a silicon precursor compound.
1H-NMR (C6D6): δ 0.21(s, 9H(—Si(CH3)3)), 0.26(s, 6H(—Si(CH3)2N—)), 0.34(s, 6H(CH3OSi(CH3)2Si—)), 1.18(d, 6H(—NCH(CH3)2)), 3.29(s, 3H(CH3O—)), 3.37(m, 1H(—NCH(CH3)2))
In Example 6, dimethylsilylisopropylmethoxytetramethyldisilanamine of compound (36) was prepared as a silicon precursor compound.
In the first step of Example 6, chloromethoxytetramethyldisilane was prepared in the same manner as in Example 5.
In the second step of Example 6, a 1-liter flask in an anhydrous and inert atmosphere was charged with 92 g (0.78 mole) of isopropyldimethylsilanamine ((CH3)2CHNHSiH(CH3)2) prepared in the first step of Example 3 and 472 g (5.48 moles) of n-hexane. While the temperature was maintained at −15° C., 328 ml (0.82 mole) of 2.5 M n-butyllithium (n-BuLi) was slowly added. The temperature was then gradually raised to room temperature, followed by stirring for 2 hours.
Next, in the third step of Example 6, while the mixed solution in the second step was maintained at −3° C., 162 g (0.89 mole) of chloromethoxytetramethyldisilane (CH3O(CH3)2SiSi(CH3)2Cl) was slowly added thereto, followed by raising the temperature to room temperature and stirring for 16 hours. Upon completion of the stirring, the lithium chloride (LiCl) salt was removed through filtration. The solvent in the filtrate was removed under a reduced pressure, followed by distillation to obtain 108 g (0.41 mole) of dimethylsilylisopropylmethoxytetramethyldisilanamine (CH3O(CH3)2SiSi(CH3)2N(CH(CH3)2)SiH(CH3)2) (yield: 52%) as a silicon precursor compound.
1H-NMR (C6D6): δ 0.22(d, 6H(—SiH(CH3)2)), 0.27(s, 6H(—Si(CH3)2N—)), 0.32(s, 6H(CH3OSi(CH3)2Si—)), 1.16(d, 6H(—NCH(CH3)2)), 3.28(m, 1H(—NCH(CH3)2)), 3.30(s, 3H(CH3O—)), 4.76(m, 1H(—SiH(CH3)2))
Thermogravimetric analysis (TGA) was carried out to analyze the thermal characteristics of the silicon precursor compounds prepared in Examples 1 to 6. The results are shown in
As shown in
The above results show that all of the silicon precursor compounds prepared according to the Examples of the present invention show sufficient volatility to be applied to atomic layer deposition (ALD) or chemical vapor deposition (CVD).
In order to confirm that the silicon precursor compounds prepared according to Examples 2, 3, 5, and 6 had a vapor pressure suitable for the preparation of a silicon oxide thin film through a deposition method, their vapor pressures were measured. The results are shown in
As shown in
The above vapor pressure results show that all of the silicon precursor compounds prepared according to the Examples of the present invention show a high vapor pressure of 10 Torr or more at a low temperature of about 100° C. or lower, indicating a sufficient vapor pressure to be applied to atomic layer deposition (ALD) or chemical vapor deposition (CVD).
Here, a silicon oxide thin film, SiO2, is prepared and described as a representative example, but it is not limited thereto. Silicon-containing thin films known in the art such as SiN, SiO2, and SiCN can be formed.
An experiment was carried out to form a silicon oxide thin film on a silicon substrate by using the silicon compound of Example 2, ethoxymethylsilylisopropyltrimethylsilanamine, as a precursor and using atomic layer deposition (ALD). An ALD reactor in which a precursor and a reactive gas (O3) are separately supplied in a vertical direction using a double shower head was used.
Table 1 and
The thin film deposited in the above manner was analyzed for the composition of the silicon oxide thin film by AES (Auger Electron Spectroscopy) using X-ray photoelectron spectroscopy. The results are shown in
As shown in
In addition, the step coverage and thickness of the silicon oxide thin film were observed using a transmission electron microscope (TEM) as shown in
Table 2 below shows the results of analyzing the characteristics of the specific silicon oxide thin film.
As shown in Table 2, a thick film with a thickness of 300 Å was formed at a high deposition rate at a substrate temperature of 400° C. and a deposition rate of 0.27 Å/cycle. The O/Si composition ratio of the formed thin film indicated that a silicon-containing thin film with high purity was formed.
As described above, the silicon precursor compound prepared according to the present invention is suitable for forming a silicon-containing thin film with high purity at a high deposition rate through atomic layer deposition (ALD).
The above-described embodiments are only for the purpose of describing the preferred embodiments of the present invention. The scope of the present invention is not limited to the described embodiments. Various changes, modifications, or substitutions will be possible by those skilled in the art within the technical idea and claims of the present invention. It should be understood that such embodiments fall within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0122367 | Sep 2022 | KR | national |
This application is a Continuation under 35 USC § 111(a) of International Patent Application No. PCT/KR2023/014790 filed Sep. 26, 2023, which claims priority to the KR Application No. 10-2022-0122367 filed Sep. 27, 2022. The entire contents of these applications are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2023/014790 | Sep 2023 | WO |
| Child | 19093076 | US |
