KR20120131114A

KR20120131114A - Compound and precursor composition For deposition of silicon compound

Info

Publication number: KR20120131114A
Application number: KR1020120055302A
Authority: KR
Inventors: 염호영; 최정현; 강상우
Original assignee: 주식회사 유엠티
Priority date: 2011-05-24
Filing date: 2012-05-24
Publication date: 2012-12-04

Abstract

PURPOSE: A silicone precursor containing silicone for thin film deposition is provided to ensure high thermal stability and reactivity. CONSTITUTION: A silicone precursor composition contains a compound of chemical formula 1. In chemical formula 1, R is tBu or iPr. The silicone precursor composition contains 1,3-Di-tert-butyl-1,3,2-diazasilolidine compounds of chemical formula 2. A silicone precursor composition contains 1,3-diisopropyl-1,3,2-diazasilolidine compounds of chemical formula 3. The silicone precursor composition is used for a silicone oxide film or silicone nitride film.

Description

Compound and precursor composition for deposition of silicon compound

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film containing silicon, such as a silicon oxide film or a silicon nitride film applied to a semiconductor device, or a silicon precursor for depositing the thin film, and to a silicon oxide film, a silicon nitride film, etc. The present invention relates to a silicon precursor compound and a composition for depositing a silicon oxide film or a silicon nitride film, which can be applied to a semiconductor manufacturing process for depositing a thin film containing the same.

In making a semiconductor device, silicon oxide film (SiO ₂ ) and silicon nitride film (Si ₃ N ₄ ) are each manufactured in various thicknesses and in various ways. Silicon oxide film is not only stable but also widely used as an insulator because of its excellent adhesion to a silicon semiconductor substrate and excellent electrical insulating properties, and is also used for field oxides, pad oxides, interlayer insulators, and capacitor insulators.

Recently, there is a growing demand for fabrication of not only silicon substrates and glass substrates but also organic-based semiconductor devices. Accordingly, deposition of silicon oxide films at 100 ° C. or less at which organic substances are not dissolved is also required.

Here, various methods, such as an oxidation process, a chemical vapor deposition method, and a sol-gel method, are proposed for the deposition method of a silicon oxide film. This method selects and uses different methods depending on the required thickness of the deposition, the characteristics of the thin film, and the use of the thin film.

In the case of the plasma chemical vapor deposition method in which the thin film of silicon oxide film is deposited at a relatively low temperature, the substrate is directly exposed to the plasma, which causes a problem in that the interface property of the substrate and the silicon oxide film is degraded by the plasma.

In the atomic layer deposition method, only one raw material gas may be injected at a time, and the supply cycle of the next raw material may be repeated to form a monolayer layer, and the cycle may be repeated to control the thickness of the film in nm units. Since the reaction temperature of is the deposition temperature, it is possible to form a thin film at a lower temperature than chemical vapor deposition by using an appropriate reaction material.

In the deposition of the silicon oxide film by chemical vapor deposition or atomic layer deposition, representative materials used as silicon precursors include tris (dimethyl amido) silane, tetrakis (dimethyl amido) silane, tetrakis (ethylmethylamido) silane, Bis (terress-butylamido) silanes, etc., but these generally have disadvantages of low thermal stability and reactivity.

Therefore, in order to expand the use of semiconductor devices in the field of integration and display, a silicon precursor capable of forming a thin film of a high quality silicon oxide film has to be developed, but the research results are still insufficient.

It is an object of the present invention to provide a silicon precursor compound having a significantly higher thermal stability and reactivity than a conventional silicon precursor and a composition comprising the same.

One aspect of the present invention is a compound represented by the following formula (1).

[Formula 1]

(In Formula 1, R is H, tBu or iPr, and R1 is C _n H _{2n + 1} (n = 0, 1, 2, 3 or 4).).

In Formula 1, R is more preferably tBu or iPr.

In addition, Chemical Formula 1 is 1,3-di-tert-butyl-1,3,2-diazalyolidine represented by Chemical Formula 2 (1,3-Di-tert-butyl-1,3,2-diazasilolidine May be).

[Formula 2]

In addition, it is preferable that Formula 1 is 1,3-diisopropyl-1,3,2-diazacillolidine (1,3-Diisopropyl-1,3,2-diazasilolidine) represented by the following Formula 3.

(3)

Another aspect of the invention may be a silicon precursor composition comprising the compound described above.

In addition, the silicon precursor composition is preferably for the deposition of silicon oxide film or silicon nitride film.

Other embodiments of the present invention are described in the detailed description and drawings for carrying out the invention described below.

The present invention can provide a silicon precursor compound having a significantly higher thermal stability and reactivity than a conventional silicon precursor and a composition comprising the same.

In addition, the present invention has the effect of actually obtaining a silicon precursor composition after the synthesis of the silicon precursor compound, through a purification process.

1 is a result of GC / MSD analysis after purification of the compound according to Example 1 of the present invention,
2 is a result of GC / MSD analysis before purification of the compound according to Example 2 of the present invention,
3 is a result of GC / MSD analysis after purification of the compound according to Example 2 of the present invention.
4 is a result of GC / MSD analysis before purification of the silicone compound prepared according to Comparative Example 1,
5 is a GC / MSD analysis result of the purification of the silicone compound prepared according to Comparative Example 1,
6 is a result of GC / MSD analysis before purification of the silicone compound prepared according to Comparative Example 2,
7 is a GC / MSD analysis result of the purification of the silicone compound prepared according to Comparative Example 2,
8 is a graph showing a result of passion stability test of a compound according to an embodiment of the present invention,
9 is a graph showing the results of the reactivity test of the compound according to the embodiment of the present invention,
10 is a process chart for explaining a Si oxide deposition process using a compound according to an embodiment of the present invention,
11 is a graph of vapor pressure measurement results using the compound according to one embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Compound according to an aspect of the present invention relates to a silicon precursor for thin film deposition containing silicon applied to a semiconductor device, a compound represented by the following formula (1).

[Formula 1]

(In Formula 1, R is hydrogen (H), tBu (tert-butyl) or iPr (isopropyl), and R1 is C _n H _2n ₊₁ (n = 0, 1, 2, 3 or 4).) .

The present inventors conducted research and development on various precursors used to deposit silicon oxide and / or silicon nitride, and as a result, the compound as shown in Formula 1 has high thermal stability and reactivity, and thus, the organic metal chemical vapor deposition method and When used in the semiconductor manufacturing process of depositing a silicon oxide film or a silicon nitride film using the atomic layer deposition method, after confirming that a high quality silicon oxide film and / or a silicon nitride film can be formed, this invention was completed.

More preferably, in Chemical Formula 1, R is preferably propyl (Pr), butyl (Bu), pentine, or the like having 3 or more carbon atoms, and most preferably tBu or iPr. The inventors of the present invention intend to synthesize a silicon precursor compound using R as hydrogen, methyl, ethyl, propyl (Pr), butyl (Bu), pentine, etc., and purify the compound to actually include a silicon precursor compound or the same. To obtain a composition. As a result, when R is hydrogen, methyl, or ethyl, GC / MSD analysis did not actually synthesize the silicon precursor compound. In addition, as can be seen in the experimental example described below, if any one of the two R in the formula (1) includes hydrogen, methyl, ethyl, it can be synthesized as a silicon precursor compound, but is decomposed by heat during purification Because of the purity, the desired silicon precursor compound could not be obtained.

Thus, the general formula 1 is 1,3-di-tert-butyl-1,3,2-diazarrolidine represented by the following formula (1,3-Di-tert-butyl-1,3,2-diazasilolidine May be).

[Formula 2]

In addition, the silicon precursor compound represented by Chemical Formula 2 may be derived from a compound represented by Chemical Formula 4 below.

[Formula 4]

(3)

In addition, the silicon precursor compound represented by Chemical Formula 3 may be derived from a compound represented by Chemical Formula 5 below.

[Chemical Formula 5]

Hereinafter, the present invention will be described in more detail with reference to examples, but the following examples are provided to illustrate the present invention, and the present invention is not limited to the following examples and can be variously modified and changed.

Example 1: 1,3-di- Tert -Butyl-1,3,2-diazacillolidine (1,3- Di - tert - butyl -1,3,2-diazasilolidine)

200 g (1.16 mol) of N, N'-di-tert-butylethylenediamine represented by Chemical Formula 4 was diluted in 800 mL of tetrahydrofuran, and then stored at a low temperature of −50 ° C. or lower. 928 mL (2.32 mol) of normal butyllithium (nBuLi) 2.5M Hexanes solution was added dropwise while maintaining the temperature below −50 ° C. After the reaction mixture was aged at −50 ° C. or lower for 1 hour, 117.2 g (1.16 mol) of dichlorosilane collected in 200 mL tetrahydrofuran were added dropwise while maintaining the temperature at −50 ° C. or lower. The temperature of the reaction mixture was slowly raised to room temperature and aged for 15 hours. The reaction mixture was filtered under nitrogen atmosphere and concentrated. 500 mL of hexane was added to the concentrated mixture, followed by filtration and concentration. The concentrated reaction mixture was subjected to fractional distillation under reduced pressure to obtain 120 g of a compound of formula 2 having a purity of 99.5% at 65 ° C. and 3 torr.

(GC / MSD; m / z = 200, ¹ H NMR (300 MHz, CDCl ₃ ); δ 4.32 (s, 2H, Jsia = 114.0 Hz), 2.99 (s, 4H), 1.22 (s, 18H))

Example 2: 1,3- Diisopropyl -1,3,2-diazacillolidine (1,3- Diisopropyl -1,3,2-diazasilolidine)

N, N'-diisopropylethylenediamine (N, N'-diisopropylethylenediamine) 150 g (1.04 mol) represented by Chemical Formula 5 was diluted in 800 mL of tetrahydrofuran (THF), and then normal butyllithium at a low temperature of -50 ° C or lower. 832 mL (1.74 mol) of (nBuLi) 2.5M Hexanes solution was added dropwise while maintaining the temperature below -50 ° C. After the reaction mixture was aged at −50 ° C. or lower for 1 hour, 105 g (1.04 mol) of dichlorosilane collected in 200 mL tetrahydrofuran were added dropwise while maintaining the temperature at −50 ° C. or lower. The temperature of the reaction mixture was slowly raised to room temperature and aged for 15 hours. The reaction mixture was filtered under nitrogen atmosphere and concentrated. 500 mL of hexane was added to the concentrated mixture, followed by filtration and concentration. The concentrated reaction mixture was subjected to fractional distillation under reduced pressure to obtain 81 g of the compound of formula 3 having a purity of 99.4% at 56 ° C and 5torr.

(GC / MSD; m / z = 172, ¹ H NMR (300 MHz, CDCl ₃ ); δ 4.85 (s, 2H), 3.07 (7, 2H), 3.00 (s, 4H), 1.18 (d, 12H))

Comparative example 1-ethyl-3- Tert -Butyl-1,3,2-diazacillolidine (1- Ethyl -3- tert -butyl-1,3,2-diazasilolidine)

As a silicon precursor, 1-ethyl-3-tert-butyl-1,3,2-diazacolidine (1-Ethyl-3-tert-butyl-1,3,2-) having 8 carbon atoms represented by the following formula (6) diazasilolidine) was synthesized.

[Formula 6]

The silicon precursor compound represented by Chemical Formula 6 was derived from the compound represented by Chemical Formula 7 below.

[Formula 7]

That is, 144.3 g (1.00 mol) of N-Ethyl-N'-tert-butylethylenediamine represented by Chemical Formula 7 is diluted in 700 mL of tetrahydrofuran, and then -50 ° C. At a lower temperature below, 800 mL (2.00 mol) of a normal butyl lithium (nBuLi) 2.5 M hexane (Hexanes) solution was added dropwise while maintaining the temperature below -50 ° C. After the reaction mixture was aged at −50 ° C. or lower for 1 hour, 101 g (1.00 mol) of dichlorosilane collected in 200 mL tetrahydrofuran were added dropwise while maintaining the temperature at −50 ° C. or lower. The temperature of the reaction mixture was slowly raised to room temperature and aged for 15 hours. The reaction mixture was filtered under nitrogen atmosphere and concentrated. 500 mL of hexane was added to the concentrated mixture, followed by filtration and concentration. The reaction mixture was subjected to fractional distillation under reduced pressure, but it was confirmed that the compound 6 was condensed in the decompression pump trap even when the temperature of the cultivator was increased.

(GC / MSD before pressure reduction; m / z = 172, GC; Purity = 64.5%, GC in reduced pressure purification; Purity: 17.1%)

Comparative example 2: 1-ethyl-3-isopropyl-1,3,2-diazacillolidine (1- Ethyl Synthesis of -3-isopropyl-1,3,2-diazasilolidine)

As the silicon precursor, 1-ethyl-3-isopropyl-1,3,2-diazacolidine (1-Ethyl-3-isopropyl-1,3,2-diazasilolidine) having 7 carbon atoms represented by the following general formula (8) Synthesized.

[Formula 8]

The silicon precursor compound represented by Chemical Formula 8 was derived from the compound represented by Chemical Formula 9 below.

[Chemical Formula 9]

That is, after diluting 130.2 g (1.00 mol) of N-Ethyl-N'-isopropylethylenediamine represented by Chemical Formula 9 in 700 mL of tetrahydrofuran, a low temperature of -50 ° C or lower 800 mL (2.00 mol) of normal butyl lithium (nBuLi) 2.5 M hexane (Hexanes) solution was added dropwise while maintaining the temperature below -50 ° C. After the reaction mixture was aged at −50 ° C. or lower for 1 hour, 101 g (1.00 mol) of dichlorosilane collected in 200 mL tetrahydrofuran were added dropwise while maintaining the temperature at −50 ° C. or lower. The temperature of the reaction mixture was slowly raised to room temperature and aged for 15 hours. The reaction mixture was filtered under nitrogen atmosphere and concentrated. 500 mL of hexane was added to the concentrated mixture, followed by filtration and concentration. The reaction mixture was subjected to fractional distillation under reduced pressure, but it was confirmed that the compound was not condensed even when the temperature of the cultivator was raised, and the compound was condensed in the vacuum pump trap.

(GC / MSD before pressure reduction; m / z = 158, GC; Purity = 62.6%, GC in reduced pressure purification; Purity: 13.1%)

Comparative example 3: r Methyl phosphorus Synthesis of Silicone Compound

In Formula 1, R 1 is H, and two R are methyl precursor compounds having methyl (four carbon atoms) in the same manner as in Comparative Example 1.

Comparative example 4: Synthesis of Silicon Compound in which R is Ethyl

In Formula 1, R1 was H, and two R's were each synthesized in the same manner as in Comparative Example 1 to a silicon precursor compound having ethyl (6 carbon atoms).

Experimental Example One : Example 1 to 2 and Comparative example Confirmation of the synthesis of the compound according to 1 to 4, and obtaining the silicon compound through the purification process

First, the compounds obtained in Examples 1 and 2 were purified by vacuum fractional distillation to obtain a desired silicon precursor compound.

1 is a result of GC / MSD analysis after purification of the compound according to Example 1 of the present invention, FIG. 2 is a result of GC / MSD analysis before purification of the compound according to Example 2 of the present invention, Figure 3 is GC / MSD analysis of the compound according to Example 2 after purification. As shown here, the compound of interest was sorted out by the purification process from the compounds obtained in Examples 1 and 2 of the present invention.

In comparison, when R is methyl or ethyl as in Comparative Examples 3 and 4, according to GC / MSD analysis, the silicon precursor compound was not actually synthesized.

In addition, asymmetric silicon precursor compounds were synthesized by Comparative Examples 1 and 2 having more carbon atoms than in Comparative Examples 3 and 4, and the results are shown in FIGS. 4 to 7.

4 is a GC / MSD analysis result of the purification of the silicon compound prepared according to Comparative Example 1, Figure 5 is a GC / MSD analysis result of the purification of the silicon compound prepared according to Comparative Example 1, Figure 6 is a comparative example GC / MSD analysis result of the purification of the silicone compound prepared according to 2, Figure 7 is GC / MSD analysis result of the purification of the silicone compound prepared according to Comparative Example 2.

Specifically, comparing FIG. 4 and FIG. 5, in the case of the silicon compound synthesized according to Comparative Example 1, it can be seen that the value of the corresponding substance is reduced during the purification process, which decomposes the compound by heat to reduce the purity. This confirmed that the silicone compound of Comparative Example 1 was synthesized, but the compound could not be obtained. 6 and 7, likewise, the silicon compound synthesized according to Comparative Example 1 can also be confirmed that the purity is reduced due to thermal decomposition during the purification process.

According to the above, the compounds of the comparative examples can be synthesized, but since the decomposition is reduced by heat during the purification process, it was confirmed that the production is not possible with the silicon precursor compound.

Accordingly, combining the Comparative Examples and Examples, it was confirmed that the synthesis after purification is possible only after isopropyl having at least 3 carbon atoms of R in Formula 1, and thus, it is preferable for deposition of a silicon oxide film or a silicon nitride film.

Experimental Example 2: thermal stability evaluation

Thermal stability evaluation experiments were carried out on the composition comprising the compound obtained according to Examples 1 and 2. The experiment used a modified form of IR gas cell.

The modified IR gas cell has a structure in which the cell temperature and the injection gas can be adjusted as desired. In order to evaluate the stability, the precursor was vaporized and injected into the gas cell, and the molecular structure was observed while raising the temperature of the gas cell from room temperature to 700 ° C.

8 is a graph showing the results of a passion stability test of a compound according to an embodiment of the present invention, the left side of which is 1,3-di-tert-butyl-1,3,2-diazarrolidine (1,3-Di-tert -butyl-1,3,2-diazasilolidine), on the right is 1,3-diisopropyl-1,3,2-diazacolidine (1,3-Diisopropyl-1,3,2-diazasilolidine) It is about.

As shown here, the compositions according to Examples 1 and 2 of the present invention were found to show thermal stability up to about 700 ^° C.

Experimental Example 3: reactivity evaluation

Reactivity evaluation experiments were carried out on the compositions comprising the compounds obtained according to Examples 1 and 2 above. The experiment used a modified form of IR gas cell. The temperature of the gas cell was measured by setting at room temperature and 50 ℃.

In order to evaluate the reactivity, H 2 O, which is a reaction gas generally used to make an oxide, was used. The precursor was vaporized and injected into the gas cell, and H 2 O, which is a reactive gas, was injected and the change in molecular structure was observed at the set temperature, and the degree of change was used to evaluate the reactivity.

Figure 9 is a graph of the results of the reactivity test of the compound according to an embodiment of the present invention, as shown here, in the case of the composition according to Examples 1 and 2 of the present invention with water (reactant for making an oxide) It can be seen that the reactivity is also high enough to occur at room temperature. In particular, the composition of Example 2 was found to have a significantly better reactivity at room temperature than the composition of Example 1.

Experimental Example 4 : Si Deposition of oxide

A deposition experiment of Si oxide was carried out using the composition containing the compound obtained in Examples 1 and 2 as a deposition raw material.

FIG. 10 is a flowchart illustrating a Si oxide deposition process using a compound according to an embodiment of the present invention. FIG. As shown here, the process conditions were a deposition material 3 seconds, followed by a primary purge for 3 seconds, oxygen (O ₂ ) was injected into the reaction gas for 3 seconds, the secondary purge was performed for 3 seconds. In addition, in particular, when the reaction gas is injected, plasma power (300W) is simultaneously applied to keep impurities mixed in the thin film low.

As a result, the deposition rate was 1.0 A / cycle (Example 1) and 1.5 A / cycle (Example 2), respectively, through the present process, carbon (C) was not mixed when the impurities were analyzed by XPS. Both precursors of Examples 1 and 2 were confirmed to be deposited even when water was used without oxygen plasma.

In addition, Figure 11 is a graph of vapor pressure measurement results using the compound according to an embodiment of the present invention. That is, in order to measure the vapor pressure, the precursor compositions according to Examples 1 and 2 were respectively placed in vacuum-blocked vacuum containers, and the internal pressure was lowered to 10 ^ -6 Torr. Then, after raising the measurement to the desired temperature, the pressure change at each temperature (30, 50, 70 ° C.) was measured, and a saturation pressure with no change in pressure was used as the vapor pressure. As a result, it can be confirmed that the case of Example 2 recorded a vapor pressure three times higher than that of Example 1.

On the other hand, while the present invention has been shown and described with respect to certain preferred embodiments, the invention is variously modified and modified without departing from the technical features or fields of the invention provided by the claims below It will be apparent to those skilled in the art that such changes can be made.

Claims

Silicon precursor composition comprising a compound represented by the formula (1):
[Formula 1]

(In Formula 1, R is H, tBu or iPr, and R1 is C _n H _2n ₊₁ (n = 0, 1, 2, 3 or 4).).

The method of claim 1,
R in Chemical Formula 1 is tBu or iPr silicon precursor composition.

To include a 1,3-di-tert-butyl-1,3,2-diazacolidine (1,3-Di-tert-butyl-1,3,2-diazasilolidine) compound represented by the formula (2) Characterized in the silicon precursor composition.
(2)

A silicon precursor composition comprising a 1,3-diisopropyl-1,3,2-diazalyolidine (1,3-Diisopropyl-1,3,2-diazasilolidine) compound represented by the following Chemical Formula 3 .
(3)

The silicon precursor composition according to any one of claims 1 to 4, wherein the silicon precursor composition is for depositing a silicon oxide film or a silicon nitride film.