KR101116402B1 - Novel Silicon alkoxide complexes containing silicon-silicon bonding and process for preparing thereof - Google Patents

Abstract

The present invention relates to a novel silicon alkoxide compound represented by the following formula (1) and a method for producing the same.

[Formula 1]

[In Formula ^1, A 1 and A ² are independently one or more C ₁ -C ₅ linear or branched substituted or non-substituted C ₂ -C ₅ alkylene group to the branched alkyl group and the other; R ¹ To R ⁴ are each independently a C ₁ -C ₅ linear or branched alkyl group;

a, b, m and n are each independently an integer from 0 to 2;

a + b and m + n are each independently 1 or 2.]

Since the silicon alkoxide compound according to the present invention is in a liquid state at room temperature and volatilizes at a low temperature, the silicon alkoxide compound may be usefully used as a silicon raw material for thin film deposition of various materials including silicon or in the manufacture of various alloys.

Silicon, silicon oxide precursor, silicon oxide, thin film, organometallic chemical vapor deposition (MOCVD), atomic layer deposition (ALD)

Description

Novel silicon alkoxide complexes containing silicon-silicon complexes containing silicon-silicon bonding and process for preparing

The present invention relates to a novel silicon complex compound, and relates to a silicon alkoxide compound useful as a precursor for chemical vapor deposition of a silicon or silicon oxide thin film and a method for producing the same.

Silicon oxide has been widely used as an insulator because of its stable, high quality silicon-silicon oxide interface and excellent electrical insulation properties. Recently, polycrystalline silicon thin films are used for thin film transistors (TFTs), solar cells, and the like.

The metal organic chemical vapor deposition (MOCVD) process, which is used to manufacture various oxide thin films among thin film manufacturing techniques, is relatively simple in equipment, uniform in layer covering, easy to control ingredients, and difficult to convert to mass production. There is no advantage. In order to manufacture a thin film using the MOCVD process, development of precursors used in this process and understanding of its characteristics are essential. Precursors for MOCVD must have a sufficiently high vapor pressure below 200 ° C, must be sufficiently thermally stable during heating to vaporize, and decompose rapidly without decomposition of organic matters at substrate temperatures of 350 ° C to 500 ° C, storage period Should be stable enough to air and moisture while. In addition, the precursor itself or the decomposition product should be non-toxic or low, the synthesis method should be simple and the raw material cost should be low.

The precursors that have been used to make the silicon compound into a thin film are largely classified into four compounds including silane, silane chloride, alkoxide compound and β -diketonate.

Silane is a gas at room temperature, stable to high pressures and impacts, but burns or explodes when mixed with oxygen. It should also be handled with care as it reacts with moisture to form powders or particles. Silane tetrachloride (SiCl ₄ ) is a precursor of atomic layer deposition (ALD) with H ₂ O. The silicon oxide thin film can be prepared at a reactant pressure of 1-10 Torr and a temperature of 600-800 ° K. (See JW Klaus, AW Ott, JM Johnson, and SM George, Appl . Phys . Lett . 1997 , 70 , 1092) and, like silane, react sensitive to moisture and produce thin films. Surface can be contaminated with chloride. Silane dichloride (SiH ₂ Cl ₂ ) may also be used to prepare silicon oxide thin films at 300 ° C. using atomic layer deposition with O ₂ or O ₃ ( Japanese Journal of Applied Physics , Part 2: Letters & Express Letters 2004 , 43 (3A) , L328-L33).

Among the alkoxide precursors, tetraethylorthosilicate (TEOS), which is most commonly used as a precursor for silicon oxide thin films, is liquid at room temperature and is easy to handle, but it reacts slowly with hydrolysis to SiO ₂ and ethanol. These precursors form thin films at temperatures as high as 400-900 ° C. by LPCVD (Low-Pressure Chemical Vapor Deposition) or APCVD (Atmospheric Pressure Chemical Vapor Deposition) (J. Crowell et al . , J. Vac . Sci . . Technol A 1990, 8, 1864 ];.. [L. Tedder , etc., J. Appl Phys 1991, 69, 7037];... [M. IslamRaja such as, J. Vac Sci Technol B 1993, 11, 720] And D. Williams et al . , J. Electrochem . Soc . 1988 , 134 , 657).

In addition, compounds containing β -diketonate include SiClMe (acac) ₂ , SiClPh (acac) ₂ , SiMe ₂ (acac) ₂ (acac = acetylacetonate), which are very unstable and have low yields. There is this. Si (OAc) ₂ (acac) ₂ and SiX ₂ (thd) ₂ (X = Me, O ^t Bu, O ^t Am, thd = 2,2,6,6-tetramethyl-3,5-heptanedion) Although more stable, compounds containing β -diketonate have the disadvantage of high deposition temperature during the MOCVD process due to high thermal stability (C. Xu, et al . , Inorg . Chem . 2004 , 43 , 1568); [ R. West, J. Am . Chem . Soc . 1958 , 80 , 3246; RM Pike et al . , J. Am . Chem . Soc . 1966 , 88 , 2972; DW Thompson, Inorg . Chem . 1969 , 8 , 2015] and KM Taba et al . , J. Organomet . Chem . 1985 , 280 , 27).

The present inventors have introduced a new ligand that can solve the problems of the compounds to develop a novel precursor for deposition of silicon or silicon oxide thin film with improved thermal stability and volatility.

The present invention has been made to solve the above-mentioned problems, the object of the present invention is to provide a silicon compound and a method for manufacturing the same, which are thermally stable and highly volatile and can form a high quality silicon or silicon oxide thin film. will be.

The present invention relates to novel silicone alkoxide compounds that are thermally stable, highly volatile and capable of producing pure silicon oxide at low temperatures. More specifically, the present invention relates to a silicon alkoxide compound represented by the following formula (1).

[Formula 1]

[In Formula ^1, A 1 and A ² are independently one or more C ₁ -C ₅ linear or branched substituted or non-substituted C ₂ -C ₅ alkylene group to the branched alkyl group and the other; R ¹ To R ⁴ are each independently a C ₁ -C ₅ linear or branched alkyl group;

a, b, m and n are each independently an integer from 0 to 2;

a + b and m + n are each independently 1 or 2.]

The silicon alkoxide compound according to the present invention is a complex compound containing no halogen component and an alkyloxy group coordinated in silicon, which is less sensitive to moisture and advantageous in storage, in particular metal organic chemical vapor deposition (MOCVD) or atom which requires excellent quality of oxide film. As a precursor of silicon used in the layer deposition method (ALD) there is no comparable. Therefore, it can be usefully used as a precursor for producing an oxide thin film containing silicon.

And in more detail, this invention relates to the silicon alkoxide compound represented by following formula (2).

[Formula 2]

[R ⁴ ] _3-a [R ³ O- (CH ₂ ) _y R ⁸ R ⁷ CO] _a Si-Si [O-CR ⁵ R ⁶ (CH ₂ ) _x -OR ¹ ] _n [R ² ] _{3- n}

[In Formula 2, R ¹ to R ⁸ are each independently a C ₁ -C ₅ linear or branched alkyl group;

a and n are each independently an integer of 1 or 2; x and y are each independently an integer of 1 to 3.]

R ¹ to R ⁸ of Formula 2 may be independently selected from methyl, ethyl, n-propyl, i-propyl and t-butyl.

Hereinafter, a method of preparing a silicon alkoxide compound according to the present invention will be described in more detail.

The silicon alkoxide compound of Chemical Formula 1 according to the present invention may be obtained as a starting material by reacting a silicon compound of Chemical Formula 3 with an alkali metal salt of Chemical Formula 4 and Chemical Formula 5 in an organic solvent. The reaction scheme for preparing may be represented by the following scheme 1.

The organic solvent is not particularly limited, but benzene, tetrahydrofuran, toluene, chloroform can be used.

[Formula 3]

[R ⁴ ] _{3-a- b} X ¹ _b X ² _a Si-SiX ¹ _n X ² _m [R ² ] _3-nm

[Formula 4]

M ¹ OA ¹ -OR ¹

[Formula 5]

M ² OA ² -OR ³

[In Formulas 3 to 5, X ¹ and X ² are independently of each other Cl, Br or I, and M ¹ and M ² are independently of each other Li, Na or K; A ¹ and A ² independently of one another are C ₂ -C ₅ alkylene which is unsubstituted or substituted with one or more C ₁ -C ₅ linear or branched alkyl groups; R ¹ To R ⁴ are each independently a C ₁ -C ₅ linear or branched alkyl group;

a, b, m and n are each independently an integer from 0 to 2;

a + b and m + n are each independently 1 or 2.]

[Scheme 1]

The silicon alkoxide compound, which is a novel silicon oxide precursor of Chemical Formulas 1 and 2, is a stable complex and has a high affinity for an organic solvent because a non-polar alkyl group is bonded at the α -carbon position with respect to oxygen of the alkoxide which is bonded to the metal. Metals can exist as monomers because they give steric hindrances to prevent intermolecular interactions with the oxygen of neighboring ligands. Due to these structural characteristics, the silicon alkoxide compound of Chemical Formula 1 is a stable liquid at room temperature, has high solubility in organic solvents such as benzene, tetrahydrofuran, toluene, chloroform, etc., and is highly volatile, and does not contain halogen elements. As a result, they can be used to obtain a silicon oxide thin film of better quality.

Accordingly, the present invention provides a method for producing a silicon-containing thin film, which comprises using the silicon alkoxide compound according to the present invention as a precursor. The silicon-containing thin film may be formed by chemical vapor deposition (MOCVD) or atomic layer deposition (ALD), and the chemical vapor deposition or atomic layer deposition may be deposited by a conventional method.

 The silicon alkoxide compound according to the invention is a complex compound in which an alkyloxy group is coordinated in silicon without containing a halogen component, which is less sensitive to moisture and advantageous in storage, in particular metal organic chemical vapor deposition (MOCVD) or atomic layer, which requires excellent quality of oxide film. There is no inferiority as a precursor of silicon used for the deposition method (ALD), and thus it can be usefully used as a precursor for producing an oxide thin film containing silicon. In addition, it exists in a liquid state at room temperature, and exhibits a volatilization property at a low temperature, so that it can be usefully used as a silicon raw material for manufacturing various alloys.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

All examples below were performed in an inert argon or nitrogen atmosphere using a glove box or Schlenk line. The structure of the reaction product is characterized by proton nuclear magnetic resonance spectroscopy ( ¹ H NMR), carbon atom nuclear magnetic resonance spectroscopy ( ¹³ C NMR), Fourier transform infrared spectroscopy (FT-IR) analysis and elemental analysis (EA) and thermal weight Analyzes were performed using thermogravimetric analysis / differential thermal analysis (TGA / DTA).

Example 1 1,2- bis (1 -methoxy -2- methylpropoxy - 2 - oxy ) -1,1,2,2- tetramethyl disilane [( mmp ) Me ₂ Si -SiMe ₂ ( mmp )] Synthesis I

ClMe ₂ Si-SiMe ₂ Cl + 2 Na (mmp) → (mmp) Me ₂ Si-Si-Me ₂ (mmp) + 2 NaCl

In a 250 mL Schlenk flask containing tetrahydrofuran (50 ml), 1,2-dichloro-1,1,2,2-tetramethyldisilane (1 g, 5.34 mmol) was dissolved. 2 equivalents of Nammp (1-methoxy-2-methyl-2-propoxy sodium, 1.35 g, 10.7 mmol) was dissolved in tetrahydrofuran (50 ml) and slowly added thereto, and the mixture was stirred for 12 hours. . The filtrate was filtered to remove the solvent under reduced pressure to obtain the title compound (1.4 g) as a colorless liquid (yield: 81.4%).

¹ H NMR (C ₆ D ₆ , 300.13 MHz): δ 0.39 (s, 12 H (C H ₃ ) ₃ Si), 1.30 (s, 12 H, OC (C H ₃ ) ₂ ), 3.14 (s, 6 HC H ₃ O), 1.15 (s, 4 H, OC H ₂ C).

¹³ C NMR (C ₆ D ₆ , 75.04 MHz): δ 82.6, 74.8, 59.2, 28.1, 2.94.

Elemental Analysis C ₁₄ H ₃₄ O ₄ Si ₂ {calculated (calculated)}: C, 50.76 (52.13); H, 6.40 (10.62).

Proton nuclear magnetic resonance spectroscopy ( ¹ H NMR) analysis results of the silicon oxide precursor synthesized in Example 1 in Figure 1, carbon atom nuclear magnetic resonance spectroscopy ( ¹³ C NMR) analysis results in Figure 2, Fourier transform infrared spectroscopy The results of the (FT-IR) analysis are shown in FIG. 3, and the results of thermogravimetric analysis (TGA) and differential thermal analysis (DTA) are shown in FIG. 4.

From FIG. 4, [(mmp) Me ₂ Si-SiMe ₂ (mmp)] is rapidly volatilized at 130 ° C. to lose weight to 180 ° C., and the final residual amount is 0.70%.

Example 2 1,1,2,2 -tetrakis (1 -methoxy -2 -methylpropane - 2 - oxy ) -1,2 -dimethyldisilane [( mmp ) ₂ MeSi- SiMe ( mmp ) ₂ ] Synthesis II

Cl ₂ MeSi-SiMeCl ₂ + 4 Na (mmp) → (mmp) ₂ MeSi-Si-Me (mmp) ₂ + 4 NaCl

1,1,2,2-tetrachloro-1,2-dimethylsilane (1 g, 4.38 mmol) was dissolved in a 250 mL Schlenk flask containing tetrahydrofuran (50 ml). To this was added 4 equivalents of Nammp (1-methoxy-2-methyl-2-propoxy sodium, 2.21 g, 17.5 mmol) in tetrahydrofuran (50 ml) and slowly added, and the mixture was stirred for 12 hours. . The filtrate was filtered to remove the solvent under reduced pressure to obtain the title compound (1.2 g) as a colorless liquid (yield: 54.8%).

¹ H NMR (C ₆ D ₆ , 300.13 MHz): δ 0.51 (s, 6 H (C H ₃ ) ₃ Si), 1.51 (s, 24 H, OC (C H ₃ ) ₂ ), 3.21 (s, 8 H, OC H ₂ C), 3.32 (s, 12 HC H ₃ O).

¹³ C NMR (C ₆ D ₆ , 75.04 MHz): δ 84.5, 77.0, 60.9, 29.9, 7.00.

Elemental Analysis C ₂₂ H ₅₀ O ₈ Si ₂ {calculated (calculated)}: C, 52.97 (56.35); H, 10.10 (10.80).

Proton nuclear magnetic resonance spectroscopy ( ¹ H NMR) analysis results of the silicon oxide precursor synthesized in Example 2 in Figure 5, carbon atom nuclear magnetic resonance spectroscopy ( ¹³ C NMR) analysis results in Figure 6, Fourier transform infrared spectroscopy The results of the (FT-IR) analysis are shown in FIG. 7, and the results of thermogravimetric analysis (TGA) and differential thermal analysis (DTA) are shown in FIG. 8.

From Fig. 8, [(mmp) ₂ MeSi-SiMe (mmp) ₂ ] is rapidly volatilized at 220 ° C. to lose weight to 255 ° C., and the final residual amount is 0.58%.

Figure 1 shows the results of proton nuclear magnetic resonance spectroscopy ( ¹ H NMR) analysis of the silicon alkoxide compound synthesized in Example 1.

Figure 2 shows the results of carbon atom nuclear magnetic resonance spectroscopy ( ¹³ C NMR) analysis of the silicon alkoxide compound synthesized in Example 1.

3 shows the results of Fourier transform infrared spectroscopy (FT-IR) analysis of the silicon alkoxide compound synthesized in Example 1. FIG.

Figure 4 shows the results of thermogravimetric analysis (TGA) and differential thermal analysis (DTA) of the silicon alkoxide compound synthesized in Example 1.

FIG. 5 shows the results of proton nuclear magnetic resonance spectroscopy ( ¹ H NMR) analysis of the silicon alkoxide compound synthesized in Example 2. FIG.

Figure 6 shows the results of carbon atom nuclear magnetic resonance spectroscopy ( ¹³ C NMR) analysis of the silicon alkoxide compound synthesized in Example 2.

7 shows the results of Fourier transform infrared spectroscopy (FT-IR) analysis of the silicon alkoxide compound synthesized in Example 2. FIG.

Figure 8 shows the results of thermogravimetric analysis (TGA) and differential thermal analysis (DTA) of the silicon alkoxide compound synthesized in Example 2.

Claims (6)

The silicon alkoxide compound represented by the following Chemical Formula 2 and characterized in that the liquid at room temperature: [Formula 2] [R ⁴ ] _3-a [R ³ O- (CH ₂ ) _y R ⁸ R ⁷ CO] _a Si-Si [O-CR ⁵ R ⁶ (CH ₂ ) _x -OR ¹ ] _n [R ² ] _{3- n} In Chemical Formula 2, R ¹ to R ⁸ are independently of each other methyl or ethyl; a and n are each independently an integer of 1 or 2; x and y are each independently an integer from 1 to 3. delete delete A method of preparing a silicon alkoxide compound of formula 1 by reacting a silicon compound of formula 3 with an alkali metal salt of formula 4 and formula 5 below. [Formula 1]

[Formula 3] [R ⁴ ] _3-ab X ¹ bX ² _a Si-SiX ¹ _n X ² _m [R ² ] _3-nm [Formula 4] M ¹ OA ¹ -OR ¹ [Formula 5] M ² OA ² -OR ³ [In Formula 1, Formulas 3 to 5, X ¹ and X ² are independently of each other Cl, Br or I, and M ¹ and M ² are independently of each other Li, Na or K; A ¹ and A ² are independently of each other an alkylene of C ² -C ^{5 which} is unsubstituted or substituted with one or more linear or branched alkyl groups of C ¹ -C ⁵ ; R ¹ to R ⁴ are independently of each other linear or minute of C ¹ -C ⁵ A topographic alkyl group; a, b, m and n are each independently an integer from 0 to 2; a + b and m + n are each independently 1 or 2.] A method for producing a silicon-containing thin film, comprising using the silicon alkoxide compound according to claim 1 as a precursor. The method of claim 5, The silicon-containing thin film is formed by chemical vapor deposition (MOCVD) or atomic layer deposition (ALD).

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