Precursor for low-k silicon-containing film deposition and deposition method of low-k silicon-containing film using the same

Abstract

This invention relates to a precursor for forming a low-dielectric-constant silicon-containing thin film comprising a silicon-containing compound represented by chemical formula 1, and a method for forming a thin film using the precursor. The low-dielectric-constant silicon-containing thin film precursor comprises an ethylene ether group, thus enabling the formation of high-quality silicon-containing thin films when applied to a thin film forming process.

Description

Technical Field

[0001] This invention relates to a precursor for forming silicon-containing thin films and a method for forming silicon-containing thin films using the precursor, particularly to a silicon-containing compound comprising a chemical structure containing a vinyl ether group, thereby forming a high-quality silicon-containing thin film in a suitable thin film forming process, and a method for forming silicon-containing thin films using the precursor. Prior Technology

[0002] With the miniaturization and high integration of semiconductor devices, parasitic capacitance also increases, leading to RC delay in response speed. Research and development activities aimed at solving this problem are actively underway. The main reason for the formation of parasitic capacitance is that the distance between metal wirings is too close, causing the configuration between these wirings to form a structure similar to that of a capacitor. To reduce this phenomenon, an interlayer insulating film formed between the metal wirings using an insulating material with a low dielectric constant is required.

[0003] The insulating material with low dielectric constant can be formed by spin-on dielectric (SOD) and chemical vapor deposition (CVD). Examples of such materials include fluorinated silicate glass (FSG) and SiOC films.

[0004] Examples of precursors currently used for forming low dielectric constant films include octamethylcyclotetrasiloxane (OMCTS), diethoxymethylsilane (DEMS), and tetraethoxysilane (TEOS). While the liquid state of these precursors facilitates vaporization during the deposition process, their applicability in film formation is limited due to factors such as the difficulty in achieving sufficient elastic modulus in the formed film.

[0005] For example, in Korean Patent Publication No. 10-2006-0029762, organosiloxanes such as methylethoxysilane (MTES), diethoxymethylsilane (DEMS), dimethoxymethylsilane (DMOMS), tetramethylcyclotetrasiloxane (TOMCATS), dimethyldimethoxysilane (DMDMOS), dimethyldioxosylcyclohexane (DMDOSH), and trimethylsilane (Z3MS) are used as precursors in the process of forming insulating films using SiH4 and SiF4 gases. However, the organosiloxane sources are only added to the precursors, which limits their ability to reduce the dielectric constant. Moreover, when the organosiloxane sources are used as precursors, it can also cause a decrease in the elastic modulus. Therefore, their use in thin film forming processes is relatively limited.

[0006] Furthermore, Korean Patent Registration No. 10-1215033 discloses a technique for forming high-quality silicon-containing thin films using silicon precursors such as silane, dimethyl silane, trimethyl silane, tetramethyl silane, diethyl silane, tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), octamethyltrisiloxane (OMTS), octamethylcyclotetrasiloxane (OMCTS), tetramethyldimethyldimethoxydisilane, tetramethylcyclotetrasiloxane (TOMCATS), dimethyldimethoxysilane (DMDMOS), diethoxymethylsilane (DEMS), methyltriethoxysilane (MTES), phenyldimethylsilane, and phenylsilane. However, the thin film formation method described above utilizes currently used silicon precursors, thus having the limitation of not being able to sufficiently increase the growth rate of the silicon oxide layer.

[0007] Previous technical documents

[0008] Patent documents (Patent Document 0006) Korean Patent Publication No. 10-2006-0029762 (Patent Document 0003) Korean Patent Registration No. 10-1215033 Summary of the Invention

[0009] The present invention aims to solve the problems existing in the prior art as described above, and its purpose is to provide a precursor for forming silicon-containing thin films with low dielectric constant, comprising a silicon-containing compound with a chemical structure containing a vinyl ether group, which is easy to store and handle because it is liquid at room temperature, and can ensure excellent thin film growth rate because of its high reactivity.

[0010] Furthermore, the aim is to provide a method for forming a high-quality low-dielectric-constant silicon-containing thin film by using the aforementioned low-dielectric-constant silicon-containing thin film formation precursor, which allows for adjustment of the carbon content within the film and improvement of the elastic modulus.

[0011] In order to achieve the objectives described above, the precursor for forming a low dielectric constant silicon-containing thin film of the present invention is characterized in that it comprises a silicon-containing compound represented by the following chemical formula 1. [Chemical Formula 1]

[0012] In the chemical formula 1, R1 and R2 are each independently hydrogen atoms or C1-C6 straight-chain, branched, or cyclic alkyl groups, primary or secondary amines, or phenyl groups containing C1-C6 functional groups or not containing functional groups; R3 and R4 are different from each other and are each independently hydrogen atoms or C1-C6 straight-chain, branched, or cyclic alkyl groups, allyl groups containing C1-C6 straight-chain, branched, or cyclic functional groups, vinyl groups containing C1-C6 straight-chain, branched, or cyclic functional groups, phenyl groups containing C1-C6 functional groups or not containing functional groups, or C1-C6 acetyl groups; any one or more of R3 and R4 contain vinyl groups.

[0013] At this time, one or more of R1 and R2 can be a straight-chain, branched, or cyclic alkyl group of C1-C6, and R1 to R2 can all be the same.

[0014] Furthermore, one or more of R3 and R4 may include allyl groups containing straight-chain, branched, or cyclic functional groups of C1-C6, vinyl groups containing straight-chain, branched, or cyclic functional groups of C1-C6, or acetyl groups of C1-C6.

[0015] Furthermore, the chemical formula 1 can be a silicon-containing compound represented by the following chemical formula 2 or chemical formula 3. [Chemical Formula 2] [Chemical Formula 3]

[0016] In Formula 2, X is O, S, or N. In both Formula 2 and Formula 3, R1 to R3 are defined as in Formula 1. R7 in Formula 2 and R5 to R7 in Formula 3 are each independently a hydrogen atom, 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 a C1-C6 functional group, or a phenyl group without a functional group, and n is an integer from 0 to 3.

[0017] In addition, R7 can be a C1-C4 straight-chain or branched alkyl group.

[0018] In addition, one or more of R5 and R6 can be hydrogen atoms.

[0019] Furthermore, n can be 0.

[0020] Furthermore, the precursor for forming the low dielectric constant silicon-containing thin film may also contain a solvent.

[0021] As the solvent, any one or more solvents selected from C1-C16 saturated or unsaturated hydrocarbons, ketones, ethers, glycol dimethyl ether, esters, tetrahydrofurans, and tertiary amines can be used, and the solvent may contain 1 to 99% by weight relative to the total weight of the precursor for forming the low dielectric constant silicon thin film.

[0022] The method for forming a low dielectric constant silicon-containing thin film of the present invention is characterized by comprising a process of forming a thin film on a substrate using the precursor for forming the low dielectric constant silicon-containing thin film.

[0023] At this time, the process of forming a thin film on the substrate may include a process of forming a precursor film by depositing a precursor for film formation on the surface of the substrate and a process of reacting the precursor film with a reactive gas.

[0024] Furthermore, the reactive gas can be any 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 (H), and diborane (B2H6).

[0025] Furthermore, the process for forming the precursor film may include a process of vaporizing the precursor for forming the low dielectric constant silicon-containing film and transferring it into the chamber.

[0026] Furthermore, the deposition can be performed using any of the following processes: Spin-On Dielectric (SOD), Low Temperature Plasma (LTP), Chemical Vapor Deposition (CVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), High Density Plasma Chemical Vapor Deposition (HDPCVD), Atomic Layer Deposition (ALD), or Plasma Enhanced Atomic Layer Deposition (PEALD).

[0027] Furthermore, the process of forming a thin film on a substrate may include the steps of supplying the low dielectric constant silicon-containing thin film formation precursor to the substrate and applying plasma to form the thin film.

[0028] Furthermore, the carbon content of the thin film, when measured using X-ray electron spectroscopy (XPS), can be between 5 and 25 at.

[0029] Furthermore, the refractive index (RI) of the film measured at a thickness of 500 nm can be between 1.43 and 1.52.

[0030] Furthermore, the elastic modulus of the film can be from 13 to 30 GPa.

[0031] Furthermore, the density of the thin film, calculated using the X-ray reflectance method (XRR), can be between 1.45 and 1.75 g / cm³.

[0032] Furthermore, the dielectric constant of the thin film can be between 2.8 and 3.9.

[0033] The precursor of the present invention, as a precursor of a silicon-containing compound containing a chemical structure containing vinyl ether, can exhibit excellent growth rate, and can form a high-quality low-dielectric-constant silicon-containing thin film with improved elastic modulus by adjusting the carbon content in the thin film or forming a silicon-carbon cross-linked structure (-Si-CH2-Si-), thereby providing a thin film formation method that can be used as a next-generation random access memory intermetallic dielectric (DRAM IMD) and other applications. Simple Explanation of the Diagram

[0034] Figure 1 shows the 1H-NMR analysis results of the compound obtained in Example 1. Figure 2 shows the 1H-NMR analysis results of the compound obtained in Example 2. Figure 3 shows the 1H-NMR analysis results of the compound obtained in Example 3. Figure 4 shows the 1H-NMR analysis results of the compound obtained in Example 4. Figure 5 shows the 1H-NMR analysis results of the compound obtained in Example 5. Figure 6 shows the 1H-NMR analysis results of the compound obtained in Example 6. Figure 7 shows the thermogravimetric analysis (TGA) results of the compounds obtained in Examples 3 to 6. Implementation

[0035] The present invention will now be described in more detail. The terms or words used in this specification and the claims of this invention should not be limited to their general or dictionary meanings, but should be interpreted in a way that allows the inventor to best explain their invention, in accordance with the meaning and concept of the technical idea of ​​this invention.

[0036] The precursor for forming low dielectric constant silicon-containing thin films according to the present invention is characterized in that it comprises a silicon-containing compound represented by the following chemical formula 1. [Chemical Formula 1]

[0037] In the chemical formula 1, R1 and R2 are each independently hydrogen atoms or C1-C6 straight-chain, branched, or cyclic alkyl groups, primary or secondary amines, or phenyl groups containing C1-C6 functional groups or not containing functional groups; R3 and R4 are different from each other and are each independently hydrogen atoms or C1-C6 straight-chain, branched, or cyclic alkyl groups, allyl groups containing C1-C6 straight-chain, branched, or cyclic functional groups, vinyl groups containing C1-C6 straight-chain, branched, or cyclic functional groups, phenyl groups containing C1-C6 functional groups or not containing functional groups, or C1-C6 acetyl groups; any one or more of R3 and R4 contain vinyl groups.

[0038] The silicon-containing compound represented by Formula 1 differs from existing octamethylcyclotetrasiloxanes (OMCTS) used as precursors by containing vinyl ether groups, thus increasing the film growth rate and thereby enhancing its effectiveness as a precursor.

[0039] As a specific example of the silicon-containing compound represented by Chemical Formula 1, it can be exemplified by one or more of R1 and R2 being straight-chain, branched, or cyclic alkyl groups of C1-C6, with all R1 to R2 having the same chemical structure.

[0040] Furthermore, one or more of R3 and R4 may include allyl groups containing straight-chain, branched, or cyclic functional groups of C1-C6, vinyl groups containing straight-chain, branched, or cyclic functional groups of C1-C6, or acetyl groups of C1-C6.

[0041] Preferably, the chemical formula 1 can be a silicon-containing compound represented by the following chemical formula 2 or chemical formula 3. [Chemical Formula 2] [Chemical Formula 3]

[0042] In Formula 2, X is O, S, or N. In both Formula 2 and Formula 3, R1 to R3 are defined as in Formula 1. R7 in Formula 2 and R5 to R7 in Formula 3 are each independently a hydrogen atom, 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 a C1-C6 functional group, or a phenyl group without a functional group.

[0043] The chemical formula 2 or 3 can take various chemical structures based on the functional groups. That is, n is an integer from 0 to 3, and R7 can be a C1-C4 straight-chain or branched alkyl group. In addition, one or more of R5 and R6 can be hydrogen atoms, and it can also include a chemical structure with n=0.

[0044] Furthermore, the precursor of the present invention may further include a solvent. As the solvent, any one or a mixture thereof of C1-C16 saturated or unsaturated hydrocarbons, ketones, ethers, glycol dimethyl ether, esters, tetrahydrofuran, and tertiary amines can be used. Examples of C1-C16 saturated or unsaturated hydrocarbons include toluene and heptane, while dimethyl ethylamine can be used as a tertiary amine.

[0045] In particular, when the silicon-containing compound forms a solid state at room temperature or slightly above room temperature, it is preferable to include a solvent that can dissolve it. That is, when the solvent is included, the solvent that can dissolve the silicon-containing compound will be contained in an amount that is between 1% and 99% by weight relative to the total weight of the precursor for forming the silicon-containing thin film.

[0046] Because the precursor, with or without the solvent, can be vaporized, it can be supplied to the chamber in gaseous form. Therefore, depending on the type of silicon-containing compound, when it is liquid at room temperature and can be easily vaporized, thin film formation processes can be performed without the use of a separate solvent.

[0047] That is, the method for forming a low dielectric constant 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 dielectric constant silicon-containing thin film.

[0048] Specifically, the process of forming a thin film on a substrate may include a process of forming a precursor film by depositing a precursor for film formation on the surface of the substrate, and a process of reacting the precursor film with a reactive gas. In this case, the reactive gas may be any one or more gases selected from nitrogen (N2), ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), oxygen (O2), water vapor (H2O), ozone (O3), hydrogen peroxide (H2O2), silane (SiH4), hydrogen (H), and diborane (B2H6).

[0049] In addition, the process may include the steps of vaporizing the precursor for forming the low dielectric constant silicon-containing thin film and transferring it into the chamber, or the thin film may be formed by applying plasma for deposition after the precursor for forming the low dielectric constant silicon-containing thin film is supplied to the substrate.

[0050] Specifically, the deposition process can be performed using any one of the following processes: Spin-On Dielectric (SOD), Low Temperature Plasma (LTP), Chemical Vapor Deposition (CVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), High Density Plasma Chemical Vapor Deposition (HDPCVD), Atomic Layer Deposition (ALD), or Plasma Enhanced Atomic Layer Deposition (PEALD).

[0051] For example, when using high-density plasma chemical vapor deposition (HDPCVD) processes, compared to atmospheric pressure chemical vapor deposition (APCVD), low pressure chemical vapor deposition (LPCVD), or plasma-enhanced chemical vapor deposition (PECVD), it can be performed under high vacuum and high power, thus forming thin films with dense structures and excellent mechanical properties.

[0052] Furthermore, when applying plasma, it can also be applied while the precursor for forming the low dielectric constant silicon-containing thin film, which is transferred into the chamber, and other source gases are supplied to the substrate.

[0053] For example, a low-dielectric-constant interlayer insulating film filling the gaps between the metal wiring patterns formed on the substrate can be formed by supplying the low-dielectric-constant silicon thin film forming precursor gas, oxygen, and hydrogen as a transport gas to a substrate on which metal wiring patterns are formed, and generating plasma therein. Furthermore, when it is necessary to form a fluorinated silicon insulating film, a fluorine source gas can be supplied simultaneously to form the thin film.

[0054] Furthermore, depending on the type of interlayer insulating film, an insulating film with a low dielectric constant that fills the gaps between metal wirings on the substrate can be formed by supplying a silicon source gas, a fluorine source gas, oxygen, a carbon-containing gas, and an inert gas, namely argon (Ar) or helium (He), to the substrate and generating plasma.

[0055] As the fluorine source, commonly used SiF4 can be used, while as the carbon-containing gas, hydrocarbon gases such as CH4, C2H4, C2H6, C2H2 and C6H6, or organic siloxane source gases such as methylethoxysilane (MTES), diethoxymethylsilane (DEMS), dimethoxymethylsilane (DMOMS), tetramethylcyclotetrasiloxane (TOMCATS), dimethyldimethoxysilane (DMDMOS), dimethyldioxosilylcyclohexane (DMDOSH) and trimethylsilane can be used.

[0056] The process for forming the thin film can be performed under a chamber pressure of 0.1 to 10 Torr. Furthermore, the source power for forming the plasma within the chamber is preferably 50 to 9,000 W, while the bias power is preferably 0 to 5,000 W. Alternatively, the bias power may be omitted depending on the specific circumstances.

[0057] During the thin film formation process, due to the structural characteristics of the silicon-containing compound used in this invention, tiny voids are formed when the interlayer insulating film is formed. Because of the formation of these voids as described above, the dielectric constant of the interlayer insulating film can be further reduced, thereby achieving a lower dielectric constant compared to existing interlayer insulating films.

[0058] Furthermore, because it can enhance the bonding force between silicon-containing compounds and the film surface, it can improve the mechanical properties of the formed film.

[0059] Furthermore, semiconductor devices can be manufactured using the aforementioned thin-film formation process, characterized by including a low-dielectric-constant silicon-containing thin film. In this case, the low-dielectric-constant silicon-containing thin film is an interlayer insulating film, which can be formed as a fluorinated silicate glass (FSG) film or an organic silicate glass (OSG) film, thereby reducing parasitic capacitance between wirings in the semiconductor device and forming a high-quality semiconductor device.

[0060] As described above, the thin film obtained by the thin film formation method of the present invention exhibits excellent physical properties. For example, the carbon content of the thin film, as measured by X-ray electron spectroscopy (XPS), can be 5 to 25 at%. Furthermore, the refractive index (RI) measured at a thickness of 500 nm can be 1.43 to 1.52. Furthermore, the elastic modulus can be 13 to 30 GPa. Furthermore, the density calculated using X-ray reflectance (XRR) can be 1.45 to 1.75 g / cm³. Moreover, the thin film can be formed with a low dielectric constant of 2.8 to 3.9.

[0061] Therefore, thin films with high elastic modulus and low dielectric constant can be obtained through the thin film properties described above, making them suitable for semiconductor devices such as next-generation random access memory intermetallic dielectrics (DRAM IMDs).

[0062] The effects of the present invention will be explained next through examples.

[0063] [Example 1] Preparation of 1-chloro-N,N-diethyl-1,1-dimethylsilanamine

[0064] An 8% pentane solution was cooled to a low temperature (approximately 0°C), and after adding 500 g (3.87 mol) of dimethyldichlorosilane, it was cooled to a low temperature (approximately -15 to -5°C). 561 g (7.67 mol) of diethylamine was slowly added over 2 hours, followed by stirring at room temperature for approximately 12 hours. A colorless liquid was obtained by removing the solvent from the filtrate obtained by filtering the final reactants under reduced pressure. The obtained liquid was purified under reduced pressure [48°C @ 10 torr] to obtain 586 g of the colorless liquid, namely 1-chloro-N,N-diethyl-1,1-dimethylsilanamine (yield: 91%).

[0065] The results of the obtained product measured by proton nuclear magnetic resonance (¹H-NMR) (400MHz, C6D6, 25℃) are shown in Figure 1. Characteristic peaks were observed at δ 0.46 [s, 6H, -Si(CH3)2], 1.02-1.05 [t, 6H, -SiN(CH2)2(CH3)2], and 2.86-2.91 [q, 4H, -SiN(CH2)2(CH3)2], which confirmed its chemical structure.

[0066] [Example 2] Preparation of N,N-diethyl-1,1-dimethyl-1-(prop-1-en-2-yloxy)silanamine

[0067] A 4⁻¹ 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, followed by stirring at room temperature for 1 hour and then cooling (approximately -5°C to 0°C). A mixture of 216 g (275 mL, 3.72 mol) acetone, 358 g (493 mL, 3.54 mol) triethylamine, and 0.5 L of acetonitrile was slowly added over 1 hour, followed by stirring at room temperature for approximately 6 hours. After the reaction was complete, 600 mL of pentane was added, followed by stirring for 30 minutes, after which only the upper organic layer was extracted. The extraction process was repeated 5 times. A colorless liquid was obtained by removing the collected upper organic layer under reduced pressure. The obtained liquid was purified by vacuum purification [57℃@10torr] to obtain 456.3g of colorless liquid, namely N,N-diethyl-1,1-dimethyl-1-(prop-1-en-2-yloxy)silanamine [456.3g] (yield: 87.8%).

[0068] Figure 2 shows the results of the obtained product measured by 1H-NMR (400MHz, C6D6, 25℃). Characteristic peaks were observed at 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)J= 0.8Hz], and 4.06 [s, 1H, -SiOC(CH2)(CH3)]. These peaks confirm its chemical structure.

[0069] [Example 3] Preparation of methoxydimethyl(prop-1-en-2-yloxy)silane

[0070] 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 Preparation Example 2, was added. 3.42 g (4.32 mL, 0.107 mol) of methanol was slowly added over 10 minutes, followed by stirring at room temperature for approximately 6 hours. A colorless liquid was obtained by removing the solvent from the filtrate obtained by filtering the final reactants under reduced pressure. The obtained liquid was purified by vacuum purification [38℃@45torr] to obtain 9.6g of colorless liquid, namely methoxydimethyl(prop-1-en-2-yloxy)silane [yield: 61%].

[0071] The results of the obtained product measured by proton nuclear magnetic resonance (¹H-NMR) (400MHz, C6D6, 25℃) are shown in Figure 3. Characteristic peaks were observed at 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], and 4.18 [s, 1H, -SiOC(CH2)(CH3)], which confirmed its chemical structure.

[0072] [Example 4] Preparation of ethoxydimethyl(prop-1-en-2-yloxy)silane

[0073] 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 Preparation Example 2, was added. 72.3 g (91.8 mL, 1.57 mol) of ethanol was slowly added over 30 minutes, followed by stirring at room temperature for approximately 6 hours. A colorless liquid was obtained by removing the solvent from the filtrate obtained by filtering the final reactants under reduced pressure. The obtained liquid was purified by vacuum purification [54℃@70torr] to obtain 225g of colorless liquid, namely ethoxydimethyl(prop-1-en-2-yloxy)silane [yield: 87.6%].

[0074] The results of the obtained product measured by 1H-NMR (400MHz, C6D6, 25℃) are shown in Figure 4. Characteristic peaks were observed at 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)], and 4.18 [s, 1H, -SiOC(CH2)(CH3)]. These peaks confirm its chemical structure.

[0075] [Example 5] Preparation of isopropoxydimethyl(prop-1-en-2-yloxy)silane

[0076] 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 Manufacturing Example 2, was added. 9.6 g (12.21 mL, 0.16 mol) of isopropanol was slowly added over 10 minutes, followed by a convective reaction for 3 hours. A colorless liquid was obtained by removing the solvent from the filtrate obtained by filtering the final reactants under reduced pressure. The obtained liquid was purified by vacuum purification [34℃@15torr] to obtain 4.8g of colorless liquid, namely isopropoxydimethyl(prop-1-en-2-yloxy)silane [yield: 52%].

[0077] Figure 5 shows the results of the obtained product measured by 1H-NMR (400MHz, C6D6, 25℃). Characteristic peaks were observed at 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)], and 4.13-4.23 [m, 1H, -SiOC(CH)(CH3)2]. These peaks confirm its chemical structure.

[0078] [Example 6] Preparation of ((3,3-dimethylbut-1-en-2-yl)oxy)(ethoxy)dimethylsilane

[0079] 150 mL of acetonitrile solution 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, and the mixture was stirred at room temperature for 1 hour before cooling (approximately -5 °C to 0 °C). A mixture 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, followed by stirring at room temperature for approximately 6 hours. After the reaction was complete, 30 mL of pentane was added, and after stirring for 30 minutes, only the upper organic layer was extracted. The extraction process was repeated 5 times. After cooling the collected upper organic layer (approximately -10°C), 4 g (5.1 mL, 0.087 mol) of ethanol was slowly added over 10 minutes, followed by stirring at room temperature for approximately 6 hours. A colorless liquid was obtained by removing the solvent from the filtrate obtained by filtering the final reactants under reduced pressure. The obtained liquid was purified under reduced pressure [51°C @ 10 torr] to obtain 12 g of the colorless liquid, namely (3,3-dimethylbut-1-en-2-yl)oxy)(ethoxy)dimethylsilane [((3,3-dimethylbut-1-en-2-yl)oxy)(ethoxy)dimethylsilane] (yield: 58%).

[0080] Figure 6 shows the results of the obtained product measured by 1H-NMR (400MHz, C6D6, 25℃). Characteristic peaks were observed at 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= 1.2Hz], and 4.12 [d, 1H, -SiOC(CH2)C(CH3)3, J= 1.2Hz]. These peaks confirm its chemical structure.

[0081] Figure 7 shows the thermogravimetric analysis (TGA) measurement results of Examples 3 to 6. In the region below 120°C, there was a weight reduction phenomenon with no residue, which indicates that it is suitable for use in the deposition process.

[0082] [Process Example]

[0083] A SiCOH thin film was formed using the thin film formation process of the present invention. Specifically, a carbon-containing silicon oxide thin film was formed by simultaneously implanting a silicon precursor and oxygen and helium using CN1 Corporation's 6" ATOMIC PREMIUM.

[0084] To ensure stable silicon precursor injection during the process, helium (He) gas was used as the transport gas in a precursor canister to supply the precursor to the reactor. Oxygen was then used as a reactant, and a carbon-containing silicon oxide film was deposited via plasma-enhanced chemical deposition (PECD). The substrate temperature was heated to 300°C, and a 100–300 W radio frequency (RF) power supply at a frequency of 13.56 MHz was provided by the plasma. The reactor pressure was maintained at 2 Torr.

[0085] Thin films were deposited while varying process conditions, including plasma application conditions, reactive gas flow rates, and transport gas flow rates. The dielectric constant, density, and carbon content of each deposited film were measured. The refractive index (RI) of the deposited films was analyzed in the range of 1.3–5.0 eV using ellipsometry, and the refractive index at 1.96 eV is listed in Table 1. The elemental composition ratio, including carbon content, within the films was measured using X-ray electron spectroscopy (XPS), and the density was measured using X-ray reflectance (XRR). The dielectric constant was measured by contacting the deposited film with a mercury probe (Hg-probe) at an AC frequency of 250 Hz. The elastic modulus was measured using a nanoindenter at a thickness of 20% of the thickness starting from the surface of the deposited film.

[0086] The deposition conditions and measurement results for each film are shown in Table 1 below.

[0087] [Table 1] Sample sedimentary conditions Measured values Radio frequency (RF) power [W] He traffic [sccm] O2 flow [sccm] Electrode spacing [mm] Refractive index (RI) Dielectric constant elastic modulus [GPa] X-ray electron spectroscopy (XPS) Carbon content [at.%] X-ray reflectance method (XRR) density [g / cm3] 1 300 300 40 20 1.457 3.09 27.53 12.66 1.66 2 300 300 70 20 1.454 3.28 26.35 8.68 1.67 3 300 300 100 20 1.449 3.39 24.79 8.85 1.68 4 300 300 140 20 1.447 3.47 24.61 7.72 1.68 5 300 300 180 20 1.442 3.66 26.45 6.60 1.71 6 300 300 10 20 1.509 3.26 26.60 19.55 1.64 7 300 300 10 30 1.500 3.07 24.37 19.38 1.63 8 300 300 10 40 1.479 3.18 21.70 19.64 1.59 9 200 300 10 20 1.498 3.33 26.54 17.30 1.66 10 350 300 10 20 1.507 3.40 27.83 19.10 1.67 11 300 300 20 40 1.456 3.04 16.65 17.97 1.55 12 300 300 40 40 1.438 2.95 16.89 15.02 1.51 13 300 250 40 40 1.426 2.94 15.71 14.24 1.51 14 300 350 40 40 1.444 3.02 16.31 14.26 1.53

[0088] The results in Table 1 confirm that the fabricated thin film, as a low-dielectric material, can be used to reduce the response speed (RC) delay of semiconductor devices. Low-dielectric materials in the semiconductor device field are evaluated based on dielectric constant and elastic modulus. In this field, thin films with a lower dielectric constant and a higher elastic modulus are considered superior. While the dielectric constant can be reduced by introducing carbon-containing functional groups based on silicon oxide, this tends to decrease the elastic modulus. In other words, there is a trade-off between dielectric constant and elastic modulus. The thin film obtained using the thin film formation method of the present invention is evaluated as a film that simultaneously satisfies the excellent qualities of multiple physical properties as described above.

[0089] The present invention has been described above with reference to preferred embodiments; however, the present invention is not limited to these embodiments. Those skilled in the art can make various modifications and alterations to the present invention without departing from its spirit. These modifications and alterations should be understood to be included within the scope of the appended patent claims.

[0090] none

Claims

1. A precursor for forming a low dielectric constant silicon-containing thin film, comprising a silicon-containing compound represented by the following chemical formula 1: [Chemical Formula 1] In this chemical formula 1, R1 and R2 are each independently a primary or secondary amine, or a phenyl group containing a C1-C6 functional group or not containing a functional group, R3 and R4 are different from each other and are each independently a hydrogen atom or an alkyl group with a C1-C6 straight-chain, branched, or cyclic functional group, an allyl group with a C1-C6 straight-chain, branched, or cyclic functional group, a phenyl group with a C1-C6 functional group or not containing a functional group, or an acetyl group with a C1-C6, wherein this chemical formula 1 is a silicon-containing compound represented by the following chemical formula 2 or chemical formula 3: [Chemical Formula 2] [Chemical Formula 3] In this chemical formula 2, X is O, S, or N; In Formula 2 and Formula 3, R1 to R3 are defined as in Formula 1; and R7 in Formula 2 and R5 to R7 in Formula 3 are each independently a hydrogen atom, an alkyl group with a straight-chain, branched or cyclic functional group of C1-C6, an allyl group containing a straight-chain, branched or cyclic functional group of C1-C6, a vinyl group containing a straight-chain, branched or cyclic functional group of C1-C6, a phenyl group containing a functional group of C1-C6 or not containing a functional group, and n is an integer from 0 to 3.

2. The precursor for forming a low dielectric constant silicon-containing thin film as described in claim 1, wherein R1 to R2 are all identical.

3. The precursor for forming a low dielectric constant silicon-containing thin film as claimed in claim 1, wherein one or more of R3 and R4 comprises allyl containing straight-chain, branched or cyclic functional groups of C1-C6, vinyl containing straight-chain, branched or cyclic functional groups of C1-C6, or acetyl containing C1-C6.

4. The precursor for forming a low dielectric constant silicon-containing thin film as described in claim 1, wherein R7 is a C1-C4 straight-chain or branched alkyl group.

5. The precursor for forming a low dielectric constant silicon-containing thin film as described in claim 1, wherein one or more of R5 and R6 are hydrogen atoms.

6. The precursor for forming a low dielectric constant silicon-containing thin film as described in claim 1, wherein n is 0.

7. The precursor for forming a low dielectric constant silicon-containing thin film as described in claim 1, further comprising a solvent.

8. The precursor for forming a low dielectric constant silicon-containing thin film as described in claim 7, wherein the solvent is any one or more of a C1-C16 saturated or unsaturated hydrocarbon, ketone, ether, glycol dimethyl ether, ester, tetrahydrofuran, and tertiary amine.

9. The precursor for forming a low dielectric constant silicon-containing thin film as described in claim 7, wherein the solvent comprises 1 to 99% by weight relative to the total weight of the precursor for forming a low dielectric constant silicon-containing thin film.

10. A method for forming a low dielectric constant silicon-containing thin film, comprising a process of forming a thin film on a substrate using a low dielectric constant silicon-containing thin film forming precursor as described in any one of claims 1 to 9.

11. A method for forming a low dielectric constant silicon-containing thin film as described in claim 10, wherein the process of forming the thin film on a substrate includes: A process for forming a precursor film by depositing a precursor for film formation on the surface of a substrate; And the process of reacting the precursor film with a reactive gas.

12. The method for forming a low dielectric constant silicon-containing thin film as described in claim 11, wherein the reactive gas is any one or more selected from 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).

13. The method for forming a low dielectric constant silicon-containing thin film as claimed in claim 11, wherein the process of forming the precursor thin film includes a process of vaporizing the precursor for forming the low dielectric constant silicon-containing thin film and transferring it into a chamber.

14. A method for forming a low dielectric constant silicon-containing thin film as described in claim 11, wherein the 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.

15. A method for forming a low-dielectric-constant silicon-containing thin film as described in claim 10, wherein the process of forming the thin film on a substrate includes: The step of forming the thin film by supplying the low dielectric constant silicon-containing thin film precursor to the substrate and applying plasma.

16. A method for forming a low dielectric constant silicon-containing thin film as described in claim 10, wherein the carbon content of the thin film, when measured using X-ray electron spectroscopy (XPS), is 5 to 25 at.

17. A method for forming a low dielectric constant silicon-containing thin film as described in claim 10, wherein the refractive index (RI) of the thin film measured at a thickness of 500 nm is 1.43 to 1.

52.

18. A method for forming a low dielectric constant silicon-containing thin film as described in claim 10, wherein the elastic modulus of the thin film is 13 to 30 GPa.

19. A method for forming a low dielectric constant silicon-containing thin film as described in claim 10, wherein the density of the thin film, calculated using the X-ray reflectance method (XRR), is 1.45 to 1.75 g / cm³.

20. A method for forming a low dielectric constant silicon-containing thin film as described in claim 10, wherein the dielectric constant of the thin film is 2.8 to 3.9.

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