Precursor for forming low-dielectric constant silicon-containing thin film and method for forming low-dielectric constant silicon-containing thin film by using same

Abstract

The present invention relates to: a precursor for forming a low-dielectric constant silicon-containing thin film, the precursor containing a silicon-containing compound represented by chemical formula 1; and a method for forming a thin film by using the precursor. The precursor for forming a low-dielectric constant silicon-containing thin film contains a vinyl ether group and thus can form a high-quality silicon-containing thin film when applied to a thin film forming process.

Description

A precursor for forming a low-k silicon-containing thin film and a method for forming a low-k silicon-containing thin film using the same.

[0001] The present invention relates to a precursor for forming a silicon-containing thin film and a method for forming a silicon-containing thin film using the same, and more particularly, to a precursor for forming a silicon-containing thin film capable of forming a high-quality silicon-containing thin film when applied to a thin film forming process, including a silicon-containing compound having a chemical structure including a vinyl ether group, and a method for forming a silicon-containing thin film using the same.

[0002] As semiconductor devices become smaller and more integrated, parasitic capacitance increases, which in turn causes response speed delay (RC delay). Research and development are being conducted to address this. This parasitic capacitance is primarily caused by the metal wirings becoming very close together, resulting in the arrangement of the metal wirings having a structure similar to that of a capacitor. To reduce this, it is necessary to form the interlayer insulating film formed between the metal wirings with an insulating material having a low dielectric constant.

[0003] The insulating material having the above low dielectric constant can be formed by the spin-on dielectric (SOD) method and the chemical vapor deposition (CVD) method, and examples thereof include a fluorinated silicon oxide film (Fluorinated Silicate Glass, FSG) and a SiOC film.

[0004] Conventionally, precursors used to form low-k thin films include octamethylcyclotetrasiloxane (OMCTS), diethoxymethylsilane (DEMS), and tetraethoxyorthosilicate (TEOS). These precursors are in a liquid state, which is advantageous for vaporization for the deposition process, but their application to the thin film formation process is limited, such as difficulty in obtaining a sufficient elastic modulus in the formed thin film.

[0005] For example, in the Republic of Korea Patent Publication No. 10-2006-0029762, MTES, DEMS, DMOMS, TOMCATS, DMDMOS, DMDOSH, Z3MS, etc. are used as organosiloxane source gases in a process of forming an insulating film using SiH4 and SiF4 gases. However, the organosiloxane source is additionally added to the precursor, so there is a limit to lowering the dielectric constant. In addition, when the organosiloxane source is used as a precursor, there is a problem that the elastic modulus is lowered, which limits its use in the thin film formation process.

[0006] In addition, Korean Patent Publication No. 10-1215033 discloses a technology for forming a high-quality silicon-containing thin film using silicon precursors such as silane, dimethylsilane, trimethylsilane, tetramethylsilane, diethylsilane, tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS), octamethyltrisiloxane (OMTS), octamethylcyclotetrasiloxane (OMCTS), tetramethyldimethyldimethoxydisilane, tetramethylcyclotetrasiloxane (TOMCATS), dimethyl dimethoxysilane (DMDMOS), diethoxymethylsilane (DEMS), methyltriethoxysilane (MTES), phenyldimethylsilane, and phenylsilane. However, this thin film forming method has a limitation in that it cannot sufficiently increase the growth speed of the silicon oxide layer because it uses a conventional silicon precursor.

[0007] The present invention has been devised in consideration of the above-mentioned prior arts, and its purpose is to provide a precursor for forming a low-k silicon-containing thin film, which comprises a silicon-containing compound having a chemical structure including a vinyl ether group, is liquid at room temperature, is easy to store and handle, and has high reactivity, resulting in an excellent thin film growth rate.

[0008] In addition, the purpose is to provide a method for forming a high-quality low-k silicon-containing thin film having an improved elastic modulus by controlling the carbon content in the thin film using the precursor for forming the low-k silicon-containing thin film.

[0009] In order to achieve the above purpose, the precursor for forming a low dielectric constant silicon-containing thin film of the present invention is characterized by including a silicon-containing compound represented by the following chemical formula 1.

[0010] [Chemical Formula 1]

[0011]

[0012] In the above chemical formula 1,

[0013] R1 and R2 are each independently a hydrogen atom or a C1-C6 straight-chain, branched or cyclic alkyl group, a primary or secondary amine group, or a phenyl group containing or not containing a C1-C6 functional group, R3 and R4 are different from each other and each independently a hydrogen atom or a C1-C6 straight-chain, branched or cyclic alkyl group, an allyl group containing a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group containing a C1-C6 straight-chain, branched or cyclic functional group, a phenyl group containing or not containing a C1-C6 functional group, or a C1-C6 acetyl group, and one or more of R3 and R4 includes a vinyl group.

[0014] At this time, at least one of R1 and R2 may be a straight-chain, branched or cyclic alkyl group of C1-C6, and all of R1 to R2 may be the same.

[0015] In addition, at least one of the R3 and R4 may include an allyl group including a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group including a C1-C6 straight-chain, branched or cyclic functional group, or a C1-C6 acetyl group.

[0016] In addition, the chemical formula 1 may be a silicon-containing compound represented by the following chemical formula 2 or chemical formula 3.

[0017] [Chemical Formula 2]

[0018]

[0019] [Chemical Formula 3]

[0020]

[0021] In the above chemical formula 2, X is O, S or N, R1 to R3 in the above chemical formula 2 and chemical formula 3 are the same as defined in the above chemical formula 1, R7 in the above chemical formula 2 and R5 to R7 in the above chemical formula 3 are each independently a hydrogen atom, a C1-C6 straight-chain, branched or cyclic alkyl group, an allyl group including a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group including a C1-C6 straight-chain, branched or cyclic functional group, a phenyl group including or not including a C1-C6 functional group, and n is an integer from 0 to 3.

[0022] Additionally, R7 may be a straight-chain or branched alkyl group of C1-C4.

[0023] Additionally, at least one of R5 and R6 may be a hydrogen atom.

[0024] Also, n can be 0.

[0025] Additionally, the precursor for forming the low dielectric constant silicon-containing thin film may additionally include a solvent.

[0026] The above solvent is C1-C 16 One or more solvents selected from the group consisting of saturated or unsaturated hydrocarbons, ketones, ethers, glymes, esters, tetrahydrofuran, and tertiary amines may be used, and may be included in an amount of 1 to 99 wt% based on the total weight of the precursor for forming the low-k silicon-containing thin film.

[0027] The method for forming a low-k silicon-containing thin film of the present invention is characterized by including a process of forming a thin film on a substrate using the precursor for forming the low-k silicon-containing thin film.

[0028] At this time, the process of forming a thin film on the substrate may include a process of forming a precursor thin film by depositing a precursor for forming the thin film on the surface of the substrate, and a process of reacting the precursor thin film with a reactive gas.

[0029] Additionally, the reactive gas may be one or more of nitrogen (N2), ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), oxygen (O2), water vapor (H2O), ozone (O3), hydrogen peroxide (H2O2), silane (SiH4), hydrogen (H2), and diborane (B2H6).

[0030] Additionally, the process of forming the precursor thin film may include a process of vaporizing the precursor for forming the low-k silicon-containing thin film and transporting it into the chamber.

[0031] Additionally, the deposition may be performed by any one of a Spin-On Dielectric (SOD) process, a Low Temperature Plasma (LTP) process, a Chemical Vapor Deposition (CVD) process, a Plasma Enhanced Chemical Vapor Deposition (PECVD) process, a High Density Plasma Chemical Vapor Deposition (HDPCVD) process, an Atomic Layer Deposition (ALD) process, or a Plasma Enhanced Atomic Layer Deposition (PEALD) process.

[0032] In addition, the process of forming a thin film on the substrate may include a step of supplying a precursor for forming a thin film containing low dielectric constant silicon to the substrate and applying plasma to form a thin film.

[0033] Additionally, the thin film may have a carbon content of 5 to 25 at% as measured by X-ray photoelectron spectroscopy (XPS).

[0034] Additionally, the thin film may have a refractive index (RI) of 1.43 to 1.52 measured at a thickness of 500 nm.

[0035] Additionally, the thin film may have an elastic modulus of 13 to 30 GPa.

[0036] Additionally, the thin film may have a density of 1.45 to 1.75 g / cm3 as measured by X-ray reflectometry (XRR).

[0037] Additionally, the thin film may have a dielectric constant of 2.8 to 3.9.

[0038] The precursor according to the present invention includes a silicon-containing compound having a chemical structure including a vinyl ether group, exhibits an excellent growth rate as a precursor, and can form a high-quality low-k silicon-containing thin film having an improved elastic modulus by controlling the carbon content in the thin film or forming a silicon-carbon cross-linking structure (-Si-CH2-Si-), and can provide a method for forming a thin film that can be utilized for purposes such as next-generation DRAM IMD.

[0039] Figure 1 is a diagram of a compound obtained by Example 1. 1 This is the result of H-NMR analysis.

[0040] Figure 2 is a diagram of a compound obtained by Example 2. 1 This is the result of H-NMR analysis.

[0041] Figure 3 is a diagram of a compound obtained by Example 3. 1 This is the result of H-NMR analysis.

[0042] Figure 4 is a diagram of a compound obtained by Example 4. 1 This is the result of H-NMR analysis.

[0043] Figure 5 is a diagram of a compound obtained by Example 5. 1 This is the result of H-NMR analysis.

[0044] Figure 6 is a diagram of a compound obtained by Example 6. 1 This is the result of H-NMR analysis.

[0045] Figure 7 shows the TGA analysis results of the compounds obtained by Examples 3 to 6.

[0046] The present invention will be described in more detail below. Terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Rather, they should be interpreted in a way that is consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention.

[0047] A precursor for forming a low-k silicon-containing thin film according to the present invention is characterized by including a silicon-containing compound represented by the following chemical formula 1.

[0048] [Chemical Formula 1]

[0049]

[0050] In the above chemical formula 1,

[0051] R1 and R2 are each independently a hydrogen atom or a C1-C6 straight-chain, branched or cyclic alkyl group, a primary or secondary amine group, or a phenyl group containing or not containing a C1-C6 functional group, R3 and R4 are different from each other and each independently a hydrogen atom or a C1-C6 straight-chain, branched or cyclic alkyl group, an allyl group containing a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group containing a C1-C6 straight-chain, branched or cyclic functional group, a phenyl group containing or not containing a C1-C6 functional group, or a C1-C6 acetyl group, and one or more of R3 and R4 includes a vinyl group.

[0052] The silicon-containing compound represented by the above chemical formula 1 contains a vinyl ether group, unlike octamethylcyclotetrasiloxane (OMCTS), which is used as a conventional precursor, and thus can increase the thin film growth rate, thereby improving the effectiveness as a precursor.

[0053] As a specific example of the silicon-containing compound represented by the above chemical formula 1, at least one of R1 and R2 may be a C1-C6 straight-chain, branched, or cyclic alkyl group, and all of R1 to R2 may exemplify the same chemical structure.

[0054] In addition, at least one of the R3 and R4 may include an allyl group including a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group including a C1-C6 straight-chain, branched or cyclic functional group, or a C1-C6 acetyl group.

[0055] Preferably, the chemical formula 1 may be a silicon-containing compound represented by the following chemical formula 2 or chemical formula 3.

[0056] [Chemical Formula 2]

[0057]

[0058] [Chemical Formula 3]

[0059]

[0060] In the above chemical formula 2, X is O, S or N, R1 to R3 in the above chemical formula 2 and chemical formula 3 are the same as defined in the above chemical formula 1, and R7 in the above chemical formula 2 and R5 to R7 in the above chemical formula 3 are each independently a hydrogen atom, a C1-C6 straight-chain, branched or cyclic alkyl group, an allyl group including a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group including a C1-C6 straight-chain, branched or cyclic functional group, or a phenyl group including or not including a C1-C6 functional group.

[0061] The above chemical formula 2 or 3 can exemplify various types of chemical structures depending on the functional group. That is, n can be an integer from 0 to 3, and R7 can be a straight-chain or branched alkyl group of C1-C4. In addition, at least one of R5 and R6 can be a hydrogen atom, and a chemical structure in which n is 0 can also be included.

[0062] In addition, the precursor of the present invention may additionally include a solvent. The solvent may be C1-C 16 Any one or a mixture of saturated or unsaturated hydrocarbons, ketones, ethers, glymes, esters, tetrahydrofuran, and tertiary amines may be used. The C1-C 16 Examples of saturated or unsaturated hydrocarbons include toluene and heptane, and examples of tertiary amines include dimethylethylamine.

[0063] In particular, when the silicon-containing compound forms a solid state at room temperature or a temperature slightly higher than that, it is preferable to include a solvent capable of dissolving it. That is, when the solvent is included, it is included in a solvent and content capable of dissolving the silicon-containing compound, and it is preferable to include it in an amount of 1 to 99 wt% based on the total weight of the precursor for forming the silicon-containing thin film.

[0064] Since the precursor, with or without the solvent, is vaporizable, it can be supplied into the chamber in the form of a precursor gas. Accordingly, depending on the type of silicon-containing compound, if it exists in a liquid state at room temperature and can be easily vaporized, the thin film formation process can be performed without a separate solvent.

[0065] That is, the method for forming a low-k silicon-containing thin film of the present invention may include a process of forming a thin film on a substrate using a precursor for forming a low-k silicon-containing thin film.

[0066] Specifically, the process for forming a thin film on a substrate may include a process for forming a precursor thin film by depositing a precursor for forming the thin film on the surface of the substrate, and a process for reacting the precursor thin film with a reactive gas. At this time, the reactive gas may be one or more of nitrogen (N2), ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), oxygen (O2), water vapor (H2O), ozone (O3), hydrogen peroxide (H2O2), silane (SiH4), hydrogen (H2), and diborane (B2H6).

[0067] In addition, the step of vaporizing the precursor for forming the low-k silicon-containing thin film and transporting it into the chamber may be included, and the thin film may be formed by supplying the precursor for forming the low-k silicon-containing thin film onto a substrate and then applying plasma to deposit the precursor.

[0068] Specifically, the deposition process may be performed by any one of a Spin-On Dielectric (SOD) process, a Low Temperature Plasma (LTP) process, a Chemical Vapor Deposition (CVD) process, a Plasma Enhanced Chemical Vapor Deposition (PECVD) process, a High Density Plasma Chemical Vapor Deposition (HDPCVD) process, an Atomic Layer Deposition (ALD) process, or a Plasma Enhanced Atomic Layer Deposition (PEALD) process.

[0069] For example, when the HDPCVD process is applied, it can be performed under high vacuum and high power compared to the atmospheric pressure chemical vapor deposition (APCVD), low pressure chemical vapor deposition (LPCVD), or plasma enhanced chemical vapor deposition (PECVD), so it is possible to form a thin film that is structurally dense and has excellent mechanical properties.

[0070] In addition, when applying plasma, the plasma may be applied while a source gas other than the precursor for forming the low-k silicon-containing thin film transferred into the chamber is supplied to the substrate.

[0071] For example, by supplying a precursor gas for forming a low-k silicon-containing thin film, oxygen gas, and a carrier gas, hydrogen gas, onto a substrate on which a metal wiring pattern is formed, and generating plasma therein, a low-k interlayer insulating film that fills the gap between the metal wiring patterns formed on the substrate can be formed. In addition, when it is desired to form a silicon fluoride insulating film, a fluorine source gas can be supplied together to form the thin film.

[0072] In addition, depending on the type of interlayer insulating film, a low dielectric constant insulating film that fills the gap between metal wiring patterns on the substrate can be formed by supplying an inert gas such as argon (Ar) or helium (He) gas together with a silicon source gas, a fluorine source gas, an oxygen gas, or a gas containing carbon on the substrate and generating plasma.

[0073] As the above fluorine source, SiF4, which is commonly used, can be used, and as the carbon-containing gas, a hydrocarbon gas such as CH4, C2H4, C2H6, C2H2, C6H6, or an organosiloxane source gas such as methylethoxysilane (MTES), diethoxymethylsilane (DEMS), dimethoxymethylsilane (DMOMS), tetramethylcyclotetrasiloxane (TOMCATS), dimethyldimethoxysilane (DMDMOS), dimethyldeoxysilylcyclohexane (DMDOSH), or trimethylsilane can be used.

[0074] The process for forming the above thin film can be performed under chamber pressure conditions of 0.1 to 10 Torr. In addition, the source power for forming plasma within the chamber is appropriately 50 to 9,000 W, and the bias power is appropriately 0 to 5,000 W. In addition, the bias power may not be applied in some cases.

[0075] In the above-described thin film formation process, the structural characteristics of the silicon-containing compound used in the present invention cause the formation of microscopic voids when the interlayer insulating film is formed. By forming these voids, the dielectric constant of the interlayer insulating film can be further reduced, and a lower dielectric constant can be achieved compared to existing interlayer insulating films.

[0076] In addition, the mechanical properties of the formed thin film are improved because the bonding strength between the silicon-containing compound and the thin film surface is improved.

[0077] In addition, by applying the above thin film formation process, a semiconductor device characterized by including a low-k silicon-containing thin film can be manufactured. At this time, the low-k silicon-containing thin film forms an FSG (Fluorinated Silicate Glass) film or an OSG (Organo Silicate Glass) film as an interlayer insulating film, thereby reducing parasitic capacitance between wirings of the semiconductor device, thereby forming a high-quality semiconductor device.

[0078] In this way, the thin film obtained by applying the thin film forming method of the present invention exhibits excellent physical properties. For example, the thin film may have a carbon content of 5 to 25 at% as measured by X-ray photoelectron spectroscopy (XPS). In addition, the refractive index (RI) measured at a thickness of 500 nm may be 1.43 to 1.52. In addition, the elastic modulus may be 13 to 30 GPa. In addition, the density calculated by X-ray reflectometry (XRR) may be 1.45 to 1.75 g / cm3. In addition, the thin film may form a low-k thin film having a dielectric constant of 2.8 to 3.9.

[0079] Therefore, a low dielectric thin film with a high elastic modulus can be obtained through these thin film properties, and thus can be used in semiconductor devices such as next-generation DRAM IMD.

[0080] The effects of the present invention are explained through the following examples.

[0081] [Example 1] Preparation of 1-chloro-N,N-diethyl-1,1-dimethylsilanamine

[0082] An 8 liter pentane solution was cooled to a low temperature (approximately 0°C), 500 g (3.87 mol) of dimethyldichlorosilane was added, and the mixture was cooled to a low temperature (approximately -15 to -5°C). 561 g (7.67 mol) of diethylamine was slowly added over 2 hours, and the mixture was stirred at room temperature for about 12 hours. The final reactant was filtered, and the solvent of the obtained filtrate was removed under reduced pressure to obtain a colorless liquid. The obtained liquid was purified under reduced pressure [48°C@10 torr] to obtain 586 g (yield: 91%) of 1-chloro-N,N-diethyl-1,1-dimethylsilanamine as a colorless liquid.

[0083] The obtained product 1 As a result of measurement by H-NMR (400 MHz, C6D6, 25℃), as shown in Fig. 1, the characteristic peaks of δ 0.46 [s, 6H, -Si(CH3)2], 1.02-1.05 [t, 6H, -SiN(CH2)2(CH3)2], 2.86-2.91 [q, 4H, -SiN(CH2)2(CH3)2] were confirmed, allowing confirmation of the chemical structure.

[0084] [Example 2] Preparation of N,N-diethyl-1,1-dimethyl-1-(prop-1-en-2-yloxy)silanamine

[0085] A 4 liter acetonitrile solution was cooled to a low temperature (approximately -10°C), and 530.3 g (3.54 mol) of sodium iodide was added. 586.4 g of 1-chloro-N,N-diethyl-1,1-dimethylsilanamine synthesized in Example 1 was added, stirred at room temperature for 1 hour, and then cooled to (approximately -5°C to 0°C). A solution of 216 g (275 ml, 3.72 mol) of acetone, 358 g (493 ml, 3.54 mol) of triethylamine, and 0.5 liter of acetonitrile was slowly added over 1 hour, and then stirred at room temperature for approximately 6 hours. After the reaction was completed, 600 ml of pentane was added, stirred for 30 minutes, and only the upper organic layer was extracted. This extraction process was repeated 5 times. The collected upper organic layer was removed under reduced pressure to obtain a colorless liquid. The obtained liquid was purified under reduced pressure [57℃@10torr] to obtain 456.3 g (yield: 87.8%) of N,N-diethyl-1,1-dimethyl-1-(prop-1-en-2-yloxy)silanamine as a colorless liquid.

[0086] The obtained product 1 As a result of measurement by H-NMR (400 MHz, C6D6, 25℃), as shown in Fig. 2, δ 0.18 [s, 6H, -Si(CH3)2], 0.99-1.02 [t, 6H, -SiN(CH2)2(CH3)2], 1.76 [d, 3H, -SiOC(CH2)(CH3)J= 0.8Hz], 2.84-2.90 [q, 4H, -SiN(CH2)2(CH3)2] 4.04 [d, 1H, -SiOC(CH2)(CH3) The characteristic peaks of [J= 0.8Hz], 4.06 [s, 1H, -SiOC(CH2)(CH3)] were confirmed, allowing confirmation of the chemical structure.

[0087] [Example 3] Preparation of methoxydimethyl(prop-1-en-2-yloxy)silane

[0088] A 120 ml solution of pentane was cooled to a low temperature (approximately -10°C), and 20 g (0.107 mol) of N,N-diethyl-1,1-dimethyl-1-(prop-1-en-2-yloxy)silanamine synthesized in Example 2 was added. 3.42 g (4.32 ml, 0.107 mol) of methanol was slowly added over 10 minutes, and the mixture was stirred at room temperature for approximately 6 hours. The final reaction product was filtered, and the solvent of the obtained filtrate was removed under reduced pressure to obtain a colorless liquid. The obtained liquid was purified under reduced pressure [38℃@45torr] to obtain 9.6 g (yield: 61%) of methoxydimethyl(prop-1-en-2-yloxy)silane as a colorless liquid.

[0089] The obtained product 1 As a result of measurement by H-NMR (400 MHz, C6D6, 25℃), as shown in Fig. 3, the characteristic peaks of δ 0.21 [s, 6H, -Si(CH3)2], 1.81 [d, 3H, -SiOC(CH2)(CH3), J= 0.8Hz], 3.53 [s, 3H, -SiO(CH3)], 4.10-4.11 [t, 1H, -SiOC(CH2)(CH3), J= 0.8Hz] 4.18 [s, 1H, -SiOC(CH2)(CH3)] were confirmed, confirming the chemical structure.

[0090] [Example 4] Preparation of ethoxydimethyl(prop-1-en-2-yloxy)silane

[0091] A 750 ml solution of pentane was cooled to a low temperature (approximately -10°C), and 300 g (1.6 mol) of N,N-diethyl-1,1-dimethyl-1-(prop-1-en-2-yloxy)silanamine synthesized in Example 2 was added. 72.3 g (91.8 ml, 1.57 mol) of ethanol was slowly added over 30 minutes, and the mixture was stirred at room temperature for approximately 6 hours. The final reaction product was filtered, and the solvent of the obtained filtrate was removed under reduced pressure to obtain a colorless liquid. The obtained liquid was purified under reduced pressure [54℃@70torr] to obtain 225g (yield: 87.6%) of ethoxydimethyl(prop-1-en-2-yloxy)silane as a colorless liquid.

[0092] The obtained product 1 As a result of measurement by H-NMR (400 MHz, C6D6, 25℃), as shown in Fig. 4, the characteristic peaks of δ 0.20 [s, 6H, -Si(CH3)2], 1.21-1.24 [t, 3H, -SiO(CH2)(CH3)], 1.80 [s, 3H, -SiOC(CH2)(CH3], 3.77-3.82 [q, 2H, -SiO(CH2)(CH3)] 4.09 [s, 1H, -SiOC(CH2)(CH3)], 4.18 [s, 1H, -SiOC(CH2)(CH3)] were confirmed, allowing the confirmation of the chemical structure.

[0093] [Example 5] Preparation of isopropoxydimethyl(prop-1-en-2-yloxy)silane

[0094] A 120 ml solution of pentane was cooled to a low temperature (approximately -10°C), and 10 g (0.053 mol) of N,N-diethyl-1,1-dimethyl-1-(prop-1-en-2-yloxy)silanamine synthesized in Example 2 was added. 9.6 g (12.21 ml, 0.16 mol) of isopropyl alcohol was slowly added over 10 minutes, followed by reflux reaction for 3 hours. The final reaction product was filtered, and the solvent of the obtained filtrate was removed under reduced pressure to obtain a colorless liquid. The obtained liquid was purified under reduced pressure [34℃@15torr] to obtain 4.8 g (yield: 52%) of isopropoxydimethyl(prop-1-en-2-yloxy)silane as a colorless liquid.

[0095] The obtained product 1 As a result of measurement by H-NMR (400 MHz, C6D6, 25℃), as shown in Fig. 5, the characteristic peaks of δ 0.20 [s, 6H, -Si(CH3)2], 1.19-1.21 [d, 6H, -SiOC(CH)(CH3)2], 1.80 [d, 3H, -SiOC(CH2)(CH3),J= 0.8Hz], 4.08-4.10 [t, 1H, -SiO(CH2)(CH3),J= 0.8Hz], 4.17 [s, ​​1H, -SiOC(CH2)(CH3)], 4.13-4.23 [m, 1H, -SiOC(CH)(CH3)2] were confirmed, confirming the chemical structure.

[0096] [Example 6] Preparation of ((3,3-dimethylbut-1-en-2-yl)oxy)(ethoxy)dimethylsilane

[0097] A 150 ml solution of acetonitrile was cooled to a low temperature (approximately -10°C), and 15.3 g (0.102 mol) of sodium iodide was added. 16.9 g of 1-chloro-N,N-diethyl-1,1-dimethylsilanamine synthesized in Example 1 was added, stirred at room temperature for 1 hour, and then cooled to (approximately -5°C to 0°C). A solution of 10.21 g (12.7 ml, 0.102 mol) of pinacolone, 10.3 g (14.2 ml, 0.102 mol) of triethylamine, and 20 ml of acetonitrile was slowly added over 1 hour, and then stirred at room temperature for approximately 6 hours. After the reaction was completed, 30 ml of pentane was added, stirred for 30 minutes, and only the upper organic layer was extracted. This extraction process was repeated 5 times. The collected upper organic layer was cooled to (approximately -10°C), 4 g (5.1 ml, 0.087 mol) of ethanol was slowly added over 10 minutes, and then stirred at room temperature for approximately 6 hours. The final reactant was filtered, and the solvent of the obtained filtrate was removed under reduced pressure to obtain a colorless liquid. The obtained liquid was purified under reduced pressure [51°C@10 torr] to obtain 12 g (yield: 58%) of (3,3-dimethylbut-1-en-2-yl)oxy)(ethoxy)dimethylsilane as a colorless liquid.

[0098] The obtained product 1As a result of measurement by H-NMR (400 MHz, C6D6, 25℃), as shown in Fig. 6, the characteristic peaks of δ 0.20 [s, 6H, -Si(CH3)2], 1.06 [s, 9H, -SiOC(CH2) C(CH3)3], 1.21-1.25 [t, 3H, -SiO(CH2)(CH3)], 3.78-3.83 [q, 2H, -SiO (CH2)(CH3)], 4.09 [d, 1H, -SiOC(CH2)(CH3)3, J= 1.2 Hz], 4.12 [d, 1H, -SiOC(CH2)C(CH3)3, J= 1.2 Hz] were confirmed, confirming the chemical structure.

[0099] As a result of the TGA measurement for the above Examples 3 to 6, as shown in Fig. 7, weight loss was observed without residue in the region below 120°C, and thus it was determined that the samples are suitable for use in the deposition process.

[0100] [Example of the process]

[0101] A SiCOH thin film was formed through the thin film formation process of the present invention. That is, a silicon precursor, oxygen, and helium were simultaneously injected using CN1 Co., Ltd. 6" ATOMIC PREMIUM to form a silicon oxide thin film containing carbon.

[0102] To ensure stable silicon precursor injection during the process, helium (He) gas was used as a carrier gas in a precursor storage container (canister) to supply the precursor to the reactor, and oxygen was used as a reactant to deposit a carbon-containing silicon oxide thin film using plasma vapor deposition. At this time, the substrate temperature was heated to 300°C, and the plasma was supplied with 100–300 W of RF power at a frequency of 13.56 MHz. The pressure of the reactor was maintained at 2 Torr.

[0103] Thin films were deposited under different process conditions such as plasma application conditions, reactive gas, and carrier flow rates, and the dielectric constant, density, and carbon content of each deposited thin film were measured. The refractive index (RI) of the deposited thin films was analyzed in the range of 1.3 to 5.0 eV by ellipsometry, and the refractive index at 1.96 eV is attached to Table 1. The element composition ratio in the thin films, including the carbon content, was measured by XPS, and the density was measured by XRR. The dielectric constant was measured by contacting the deposited thin film using a Hg-probe, and the measurement was performed at an ac frequency of 250 Hz. The elastic modulus was measured by Nanoindenter, and the measurement was performed at a thickness point of 20% from the surface of the deposited thin film.

[0104] The deposition conditions and measurement results for each thin film are shown in Table 1 below.

[0105] Ssample Deposition Conditions Measurements RF Power [W] He Flow Rate [sccm] O2 Flow Rate [sccm] Electrode Spacing [mm] RI Dielectric Constant Elastic Modulus [GPa] XPS Carbon Content [at.%] XR Density [g / cm 3]130030040201.4573.0927.5312.661.66230030070201.4543.2826.358.681.673300300100201.4493.3924.798.851.684300300140201.4473.4724.617.721.685300300180201.4423.6626.456.601.71630030010201.5093.2626.6019.551.64730030010301.5003.0724.3719.381.6383 0030010401.4793.1821.7019.641.59920030010201.4983.3326.5417.301.661035030010201.5073.4027.8319.101.671130030020401.4563.0416.6517.971.551230030040401.4382.9516.8915.021.511330025040401.4262.9415.7114.241.511430035040401.4443.0216.3114.261.53

[0106] Looking at the results in Table 1, it can be seen that the manufactured thin film can be used as a low-k dielectric material to reduce the RC delay of semiconductor devices. Low-k dielectric materials in the field of semiconductor devices are evaluated by dielectric constant and elastic modulus, etc. Thin films with low dielectric constant and high elastic modulus are considered superior in the relevant field. There is a method to lower the dielectric constant by introducing carbon-containing functional groups based on silicon oxide, but the elastic modulus also tends to decrease. In other words, it can be seen that the dielectric constant and elastic modulus have a trade-off relationship. The thin film obtained by applying the thin film formation method of the present invention was evaluated to be an excellent quality thin film that satisfies all of these various physical properties.

[0107] While the present invention has been described with reference to preferred embodiments as described above, it is not limited to the above-described embodiments, and various modifications and variations are possible by those skilled in the art without departing from the spirit of the invention. Such modifications and variations are deemed to fall within the scope of the present invention and the appended claims.

Claims

1. A precursor for forming a low-k silicon-containing thin film comprising a silicon-containing compound represented by the following chemical formula 1. [Chemical Formula 1] In the above chemical formula 1, R1 and R2 are each independently a hydrogen atom or a C1-C6 straight-chain, branched or cyclic alkyl group, a primary or secondary amine group, or a phenyl group containing or not containing a C1-C6 functional group, R3 and R4 are different from each other and are each independently a hydrogen atom or a C1-C6 straight-chain, branched or cyclic alkyl group, an allyl group containing a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group containing a C1-C6 straight-chain, branched or cyclic functional group, a phenyl group containing or not containing a C1-C6 functional group, or a C1-C6 acetyl group, One or more of R3 and R4 contains a vinyl group.

2. In claim 1, A precursor for forming a low dielectric constant silicon-containing thin film, characterized in that at least one of the above R1 and R2 is a straight-chain, branched or cyclic alkyl group of C1-C6.

3. In claim 1, A precursor for forming a low dielectric constant silicon-containing thin film, wherein the above R1 to R2 are all the same.

4. In claim 1, A precursor for forming a low-k silicon-containing thin film, characterized in that at least one of the above R3 and R4 comprises an allyl group containing a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group containing a C1-C6 straight-chain, branched or cyclic functional group, or a C1-C6 acetyl group.

5. In claim 1, A precursor for forming a low dielectric constant silicon-containing thin film, characterized in that the chemical formula 1 above is a silicon-containing compound represented by the following chemical formula 2 or chemical formula 3. [Chemical Formula 2] [Chemical Formula 3] In the above chemical formula 2, X is O, S or N, In the above chemical formulas 2 and 3, R1 to R3 are the same as defined in the above chemical formula 1, In the above chemical formula 2, R7 and in the chemical formula 3, R5 to R7 are each independently a hydrogen atom, a C1-C6 straight-chain, branched or cyclic alkyl group, an allyl group including a C1-C6 straight-chain, branched or cyclic functional group, a vinyl group including a C1-C6 straight-chain, branched or cyclic functional group, a phenyl group including or not including a C1-C6 functional group, n is an integer from 0 to 3.

6. In claim 5, A precursor for forming a low dielectric constant silicon-containing thin film, characterized in that R7 is a straight-chain or branched alkyl group of C1-C4.

7. In claim 5, A precursor for forming a low-k silicon-containing thin film, characterized in that at least one of R5 and R6 is a hydrogen atom.

8. In claim 5, A precursor for forming a low-k silicon-containing thin film, characterized in that n is 0.

9. In claim 1, A precursor for forming a low-k silicon-containing thin film, characterized in that it additionally contains a solvent.

10. In claim 9, The above solvent is C1-C 16 A precursor for forming a low dielectric constant silicon-containing thin film, characterized in that it is one or more of a saturated or unsaturated hydrocarbon, ketone, ether, glyme, ester, tetrahydrofuran, and tertiary amine.

11. In claim 9, A precursor for forming a low-k silicon-containing thin film, characterized in that the solvent is included in an amount of 1 to 99 wt% based on the total weight of the precursor for forming a low-k silicon-containing thin film.

12. A method for forming a low-k silicon-containing thin film, characterized by comprising a process for forming a thin film on a substrate using a precursor for forming a low-k silicon-containing thin film according to any one of claims 1 to 11.

13. In claim 12, The process of forming a thin film on the above substrate is: A process of forming a precursor thin film by depositing the precursor for forming the thin film on the surface of a substrate; A process of reacting the above precursor thin film with a reactive gas; A method for forming a low dielectric constant silicon-containing thin film, characterized by including:

14. In claim 13, A method for forming a low dielectric constant silicon-containing thin film, characterized in that the reactive gas is one or more of nitrogen (N2), ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), oxygen (O2), water vapor (H2O), ozone (O3), hydrogen peroxide (H2O2), silane (SiH4), hydrogen (H2), and diborane (B2H6).

15. In claim 13, A method for forming a low-k silicon-containing thin film, characterized in that the process for forming the precursor thin film includes a process of vaporizing the precursor for forming the low-k silicon-containing thin film and transporting it into a chamber.

16. In claim 13, A method for forming a low-k silicon-containing thin film, characterized in that the above deposition is performed by any one of a spin-on dielectric (SOD) process, a low-temperature plasma (LTP) process, a chemical vapor deposition (CVD) process, a plasma enhanced chemical vapor deposition (PECVD) process, a high-density plasma chemical vapor deposition (HDPCVD) process, an atomic layer deposition (ALD) process, or a plasma enhanced atomic layer deposition (PEALD) process.

17. In claim 12, The process of forming a thin film on the above substrate is: A method for forming a low-k silicon-containing thin film, characterized by comprising a step of supplying a precursor for forming a low-k silicon-containing thin film to a substrate and applying plasma to form a thin film.

18. In claim 12, A method for forming a low-k silicon-containing thin film, wherein the thin film has a carbon content of 5 to 25 at% as measured by X-ray photoelectron spectroscopy (XPS).

19. In claim 12, A method for forming a low-k silicon-containing thin film, characterized in that the thin film has a refractive index (RI) of 1.43 to 1.52 measured at a thickness of 500 nm.

20. In claim 12, A method for forming a low dielectric constant silicon-containing thin film, characterized in that the thin film has an elastic modulus of 13 to 30 GPa.

21. In claim 12, A method for forming a low dielectric constant silicon-containing thin film, characterized in that the thin film has a density of 1.45 to 1.75 g / cm3 as measured by X-ray reflectometry (XRR).

22. In claim 12, A method for forming a low dielectric constant silicon-containing thin film, characterized in that the thin film has a dielectric constant of 2.8 to 3.9.

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