KR20200136386A - An aminosilane compound, and a composition for forming a silicone-containing film containing the aminosilane compound - Google Patents

Abstract

In the formation of a silicon-containing film, an aminosilane compound that can be decomposed at a low temperature in order to improve the film formation speed by improving the adsorption property to the substrate surface during film formation, and to enable the film formation at a lower temperature by lowering the decomposition temperature. , And an aminosilane compound capable of decomposing at a low temperature is provided as a silicon precursor.

Description

An aminosilane compound, and a composition for forming a silicone-containing film containing the aminosilane compound

The technical field of the present invention relates to a novel aminosilane compound and a composition for forming a silicone-containing film comprising the compound.

In the manufacture of semiconductor devices, silicon-containing thin films are manufactured into various types of thin films such as silicon films, silicon oxide films, silicon nitride films, silicon carbonitride films, and silicon oxynitride films by various deposition processes, and are applied in various fields. have. Among them, silicon oxide film and silicon nitride film have very excellent blocking properties and oxidation resistance, so in the manufacture of devices, insulating films, intermetallic dielectric materials, seed layers, spacers, hard masks, trench isolation, diffusion barrier films, etch stop layers, and It functions as a protective film layer.

In recent years, with the miniaturization of the device, the increase in the aspect ratio, and the diversification of the device material, a technology for forming an ultrafine thin film having excellent electrical properties at a low temperature is required. However, in the conventional film formation method using a silicon precursor, It is necessary to set the temperature to 600 DEG C or higher, and the step coverage, etching characteristics, and physical and electrical characteristics of the thin film are deteriorated.

To solve this problem, by atomic layer deposition (ALD) method, dichlorosilane (DCS: SiH ₂ Cl ₂ ) and ammonia (NH ₃ ) are activated by plasma by alternating ammonia radicals (NH ₃ ·). By supplying, a method of forming a silicon nitride film at a low temperature (300°C to 600°C) (Patent Document 1) or ALD method, reacting tetrachlorosilane (TCS: SiCl ₄ ) and water (H ₂ O) A method of forming a silicon oxide film at a low temperature (300°C to 400°C) (Patent Document 2) is proposed.

Japanese Patent Laid-Open No. 2004-281853 Japanese Patent Laid-Open No. 2005-11904

However, in the method of Patent Document 1, since the introduction of carbon into the silicon nitride film may cause structural defects, there is a concern that insulation resistance may be deteriorated. Further, in the method of Patent Document 2, there is a problem that TCS, which is a chloride, reacts with water to generate HCl, which corrodes the exhaust pipe.

The present invention has been devised under such circumstances, and does not contain carbon and halides, and in the formation of a silicon-containing film, the film formation rate is improved by improving the adsorption property to the substrate surface during film formation, and the decomposition temperature is reduced. It is a major problem to provide a silicon precursor that enables film formation at a lower temperature by lowering the temperature.

Conventionally, it was common to use an aminosilane compound having the same amino group bonded to the Si atom as a precursor for forming a silicon-containing film for reasons such as ease of synthesis, but the inventors of the present invention, as a result of intensive examination, in order to obtain the desired effect , It has been found that it is useful to use an aminosilane compound having different amino groups bonded to the Si atom as a silicon-containing film precursor. In particular, by using an aminosilane compound in which two amino groups of a specific amino group, which are a diisopropylamino group and a non-diisopropylamino group, are bonded to the Si atom as a silicon-containing film precursor, the substrate of the silicon-containing film precursor is It was found that the film formation rate was improved by improving the adsorption property to the surface, and the film formation at a lower temperature could be achieved by lowering the decomposition temperature, and thus the present invention was completed.

In other words, the present invention provides the invention of the aspect disclosed below.

Item 1 the following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

An aminosilane compound represented by.

Item 2 The following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

A precursor for forming a silicon-containing film represented by.

Item 3 The precursor according to item 2, wherein the silicon-containing film is formed by chemical vapor deposition.

Item 4 The precursor according to item 3, wherein the chemical vapor deposition is an atomic layer deposition.

Item 5 below formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both of R ¹ and R ² are isopropyl groups.)

A composition for forming a silicone-containing film containing an aminosilane compound represented by.

Item 6 The composition according to item 5, wherein the silicone-containing film is formed by chemical vapor deposition.

Item 7 The composition according to item 6, wherein the chemical vapor growth is an atomic layer deposition.

Item 8:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

As a method for producing an aminosilane compound represented by,

(a) synthesizing an aminochlorosilane compound by adding dichlorosilane and a first amine to a solvent;

(b) a filtration step of removing by-product salts by filtration;

(c) synthesizing an aminosilane compound by adding a second amine to the filtrate; And

(d) distillation step of isolating aminosilane compound by distillation

Containing, the manufacturing method.

Item 9 The first amine in the synthesis step (a) is diisopropylamine, and the aminochlorosilane compound is the following formula (1):

It is an intermediate (1) represented by and the second amine in the synthesis step (c) is

R ¹ R ² NH

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both of R ¹ and R ² are isopropyl groups.)

The production method according to item 8, which is R ¹ R ² NH represented by.

Item 10 The first amine in the synthesis step (a) is

R ¹ R ² NH

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

It is an amine compound represented by, and the aminochlorosilane compound is the following formula (2):

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

The production method according to item 8, wherein the intermediate (2) represented by and the second amine in the synthesis step (c) is diisopropylamine.

Item 11 below formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

A method for producing a silicon-containing film using an aminosilane compound represented by.

Item 12 The method for producing a silicon-containing film according to item 11, wherein the silicon-containing film is a silicon oxide film.

According to the present invention, by using a specific aminosilane compound as a silicon precursor, it has become possible to perform film formation at a lower temperature without generating structural defects or corrosive gas. Moreover, according to the method of the present invention, since the film formation speed is improved, a semiconductor device can be manufactured at a lower cost and with higher productivity.

¹ H-NMR chart of an aminosilane compound (diisopropylamino tertiary aminosilane) obtained by the production method of the present invention.
[Fig. 2] ¹ H-NMR chart of the aminosilane compound (diisopropylaminodimethylaminosilane) obtained by the production method of the present invention.

The present invention, the following formula:

(In the formula, R ¹ and R ² are each independently H, methyl group, ethyl group, n-propyl group, isopropyl (i-Pr) group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group Represents a substituent selected from the group consisting of groups, provided that the case where both of R ¹ and R ² are isopropyl groups is not included.)

It provides an aminosilane compound represented by.

Preferred specific examples of NR ¹ R ² are NH(t-Bu) and N(CH ₃ ) ₂ .

The dipole moment of the aminosilane compound may be 0.85D or more, for example, 1.0D or more, and may be 2.0D or less, and for example, 1.35D or less. Here, the dipole moment of the aminosilane compound means the amount of a vector from negative charges to positive charges derived from partial charges on an atom in the molecule of the aminosilane compound. The dipole moment can be calculated by using a commercially available molecular chemistry calculation program. For example, it can be calculated by the density functional method (B3LYP/cc-pVDZ) using Gaussian09 manufactured by Gaussian.

The method for preparing an aminosilane compound according to the present invention includes (a) a synthesis process of synthesizing an aminochlorosilane compound by adding dichlorosilane and a first amine to a solvent, and (b) removing by-product salts by filtration. And (c) a synthesis step of synthesizing an aminosilane compound by adding a second amine to the filtrate, and (d) a distillation step of isolating the aminosilane compound by distillation.

The solvent that can be used in the present invention is, for example, hydrocarbons such as hexane, cyclohexane, heptane, nonane, and decane; Halogenated hydrocarbons such as dichloroethane, dichloromethane, and chloroform; Aromatic hydrocarbons such as benzene, toluene, xylene, chlorobenzene, and trichlorobenzene; And mixtures thereof. Among these, hydrocarbons such as hexane, cyclohexane, heptane, nonane, and decane are preferable, and hexane is particularly preferably used. The amount of the solvent used is usually 0.1 to 50 times the mass of dichlorosilane.

In order to avoid hydrolysis of dichlorosilane, aminochlorosilane, and aminosilane, the reaction system is preferably carried out under anhydrous conditions, and moisture in all raw materials used is 0 to 5000 mass ppm with respect to the mass of all raw materials, Preferably, the reaction is carried out in the range of 0 to 400 mass ppm. In addition, it is preferable to use a dried reaction apparatus by performing heat drying, reduced pressure, and substitution with an inert gas such as nitrogen or argon.

In the step (a), either the first amine is dissolved in an organic solvent and dichlorosilane is added thereto, or the dichlorosilane is dissolved in an organic solvent and the first amine is added thereto. Any one is applicable to this reaction.

The amount of the first amine used is usually 1 to 4 times by mole, and preferably 1.5 to 2.5 times by mole from the viewpoint of improving the yield with respect to dichlorosilane as a raw material.

Since the reaction is an exothermic reaction, the reaction temperature is preferably carried out at a low temperature, but if the reaction temperature is too low, there is a risk of a decrease in the yield, and thus the reaction is carried out in the range of -20°C to 60°C, preferably -10 to 50°C. The reaction time is usually in the range of 0.5 to 10 hours.

In step (b), by-product salts are removed from crude products in the reactor. In order to suppress the decomposition of aminochlorosilane, it is preferable to carry out under dry inert gas, for example under nitrogen or argon. Although the filtration temperature is not uniquely determined, it is applicable from 10°C to the boiling point of the solvent used. It is preferably carried out in the range of 20°C to 65°C.

In step (c), it is synthesized by dropping a second amine to the filtrate obtained in step (b).

Although it is desired that the amount of the second amine used is 2 mol or more with respect to 1 mol of the total amount of the intermediate aminochlorosilane, it is preferably in the range of 2 to 3 moles from the viewpoint of economy.

Since the reaction is an exothermic reaction, the reaction temperature is preferably carried out at a low temperature. If the reaction temperature is too low, the yield may be lowered. Therefore, it is carried out in the range of -5°C to 60°C, preferably 0 to 50°C. The reaction time is usually in the range of 0.5 to 10 hours.

In step (d), the aminosilane compound is isolated by distillation, for example, distillation under reduced pressure. The amine and organic solvent are easily removed, and the aminosilane compound can be purified with a sufficiently high purity.

In the manufacturing method of the first aspect of the present invention, first, by reacting diisopropylamine with dichlorosilane, the following formula (1):

To prepare the intermediate (1) represented by, the intermediate (1)

R ¹ R ² NH

It is a method of producing by reacting an amine compound represented by. Here, the specific structures of R ¹ and R ² and preferable examples of NR ¹ R ² are as described above in the description of the aminosilane compound.

The reaction formula of dichlorosilane and diisopropylamine ((i-Pr) ₂ NH) is shown below.

SiH ₂ Cl ₂ + 2(i-Pr) ₂ NH → (i-Pr) ₂ NSiH ₂ Cl + (i-Pr) ₂ NH·HCl

The reaction scheme of intermediate (1) and R ¹ R ² NH is shown below.

In the production method of the second aspect of the present invention, first, by reacting R ¹ R ² NH with dichlorosilane, the following formula (2):

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

It is a method of preparing the intermediate (2) represented by and by reacting the intermediate (2) with diisopropylamine.

The reaction formula of dichlorosilane and R ¹ R ² NH is shown below.

SiH ₂ Cl ₂ + 2R ¹ R ² NH → R ¹ R ² NSiH ₂ Cl + R ¹ R ² NH·HCl

The reaction formula of the intermediate (2) and diisopropylamine is shown below.

Using the aminosilane compound according to the present invention as an intermediate of a silicon-containing film, a silicon-containing film, for example, a silicon nitride film, a silicon oxide film, or the like can be formed on a substrate. More specifically, the method for forming a silicon-containing film according to the present invention,

(e) on the substrate, the following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)

A step of adsorbing the aminosilane composition to a substrate by contacting an aminosilane composition containing an aminosilane compound represented by

(f) purging the unadsorbed aminosilane composition and by-products;

(g) injecting a reactive gas into the substrate on which the aminosilane composition is adsorbed, thereby decomposing the aminosilane to form an atomic layer; And

(h) the process of purging unreacted reactive gases and by-products

It is an atomic layer deposition method, including.

The temperature of the substrate (film formation temperature) may be performed at 100 to 600°C, preferably 100 to 550°C. From the viewpoints of the film properties and energy saving properties obtained, the temperature of the substrate may be 550°C or less, for example, 450°C or less, preferably 400°C or less, more preferably 350°C or less, and more preferably Is 325°C or less. In addition, the temperature of the substrate may be 100°C or higher, for example 150°C or higher. On the other hand, the film formation temperature may be the temperature of at least one step among (e) to (h), and is, for example, the temperature of the substrate when it comes into contact with the aminosilane composition in step (e).

The silicon-containing film is preferably formed after substitution with an inert gas such as nitrogen or argon is performed. That is, you may perform the said process (e) after inert gas substitution inside the reaction system.

The pressure at the time of injection of the aminosilane composition gas or the reactive gas in step (e) may be 0.05 to 100 Torr, preferably 0.05 to 50 Torr. From the viewpoint of energy savings and the like, the supply time of the raw material aminosilane composition gas may be 10 seconds or less, for example, 5 seconds or less, preferably 3 seconds or less, and more preferably 2 seconds or less.

Purging in step (f) can be performed by introducing an inert gas such as argon. From the viewpoint of energy savings and the like, the purge time in the step (f) may be 60 seconds or less, for example, 30 seconds or less, preferably 25 seconds or less.

The pressure at the time of injection of the aminosilane composition gas or reactive gas in the step (g) may be 0.05 to 100 Torr, preferably 0.05 to 50 Torr. From the viewpoint of energy savings and the like, the supply time of the reaction gas may be 30 seconds or less, for example, 10 seconds or less, and preferably 5 seconds or less.

In the step (g), as the reaction gas, at least one gas selected from nitrogen, ammonia, dinitrogen monoxide, nitrogen monoxide, and nitrogen dioxide may be used when forming a silicon nitride film having a Si-N bond. When forming a silicon oxide film having a Si-O bond, one or more gases selected from oxygen, ozone, and nitrogen monoxide may be used.

Purging in step (h) can be performed by introducing an inert gas such as argon. From the viewpoint of energy savings and the like, the purge time in the step (f) may be 120 seconds or less, for example, 60 seconds or less, and preferably 45 seconds or less.

The aminosilane compound in the present invention is suitably used for production of a silicon-containing film (silicon oxide film, silicon nitride film, etc.) by the ALD method. In the method for producing a silicon-containing film in the present invention, the lower limit of the ALD window may be 300°C, preferably 275°C. Further, in the method for producing a silicon-containing film in the present invention, the upper limit of the ALD window may be 550°C, preferably 525°C. Here, the ALD window generally refers to a temperature range between the temperature at which the silicon-containing film precursor compound is vaporized and the thermal decomposition temperature of the silicon-containing film precursor compound.In this specification, the ALD window is deposited by taking the film formation temperature on the horizontal axis. When the velocity is taken on the vertical axis, it can be defined as the temperature range from the point at which the deposition velocity becomes maximum to the point at which it becomes minimum.

Example

Hereinafter, the present invention will be described in detail by examples.

<Synthesis of aminosilane compound>

[Example 1: Synthesis of diisopropylamino tertiary aminosilane]

After nitrogen substitution, 101.2 g (1.0 mol) of diisopropylamine and 800 g of hexane were added to a 2000 mL flask equipped with a blow pipe, thermometer, cooling pipe, and motor stirrer, and an immersion cooler using acetone as a refrigerant. It cooled to 0 degreeC by furnace. While warming and stirring at 0°C, a gas of 50.5 g (0.5 mol) of dichlorosilane was introduced by blowing into the liquid at a rate of 50 mL per minute for 4 hours. As a result, white smoke was formed and white salt was formed. After blowing in the dichlorosilane, the internal temperature of the flask was gradually warmed to room temperature over 3 hours, and the mixture was kept warm while stirring for 5 hours. After that, amine hydrochloride as a by-product removed the main solid by filtration under reduced pressure in a nitrogen-substituted glove box to obtain a hexane solution containing diisopropylaminochlorosilane.

This diisopropylaminochlorosilane solution was added to a 2000 mL flask set with a thermometer, a cooling tube, and a motor stirrer, and a nitrogen-substituted 2000 mL flask, and cooled to 0°C by an immersion cooler using acetone as a refrigerant. 73.14 g (1.0 mol) of turmeric amine was slowly added dropwise over 2 hours while keeping the temperature at 0°C and stirring. After that, in a nitrogen-substituted glove box, by-product amine hydrochloride removed the main solid by filtration under reduced pressure to obtain a hexane solution containing diisopropylamino tertiary aminosilane.

The crude diisopropylamino tertiary aminosilane solution was distilled under atmospheric pressure at an inner temperature of 80°C to remove hexane from the crude diisopropylamino tertiary aminosilane solution, and additionally, an inner temperature of 90° C. using a distillation column, The final product was obtained with high purity by distillation under reduced pressure at 10 Torr.

GC analysis after distillation confirmed that 62.7 g (62% yield) of aminosilane compounds were obtained with a purity of 99.6 area%. The obtained aminosilane compound was identified by ¹ H-NMR and GC-MS. The attribution of ¹ H-NMR is as follows.

σ (ppm)=0.79 ((CH ₃ ) ₃ -C- NH -, 1H, s), 1.12 ([( CH ₃ ) ₂ -CH] ₂ -N-, 12H, d, J=7.0Hz), 1.19 (( CH ₃ ) ₃ -C-NH-, 9H, s), 3.27 ([(CH ₃ ) ₂ - CH ] ₂ -N-, 2H, sep), 4.57 (- SiH ₂ -, 2H, d, J =3.0Hz)

As a result of the ¹ H-NMR and GC-MS, the obtained aminosilane compound is represented by the following formula:

It was identified as diisopropylamino tertiary aminosilane represented by.

[Example 2: Synthesis of diisopropylaminodimethylaminosilane]

After nitrogen substitution, 101.2 g (1.0 mol) of diisopropylamine and 800 g of hexane were added to a 2000 mL flask equipped with an inlet pipe, thermometer, cooling pipe, and motor stirrer, and acetone was used in the refrigerant to 0℃ with an immersion cooler. Cooled down. While warming and stirring at 0°C, a gas of 50.5 g (0.5 mol) of dichlorosilane was introduced by blowing into the liquid at a rate of 50 mL per minute for 4 hours. As a result, white smoke was formed and white salt was formed. After blowing in the dichlorosilane, the internal temperature of the flask was gradually warmed to room temperature over 3 hours, and the mixture was kept warm while stirring for 5 hours. After that, amine hydrochloride as a by-product removed the main solid by filtration under reduced pressure in a nitrogen-substituted glove box to obtain a hexane solution containing diisopropylaminochlorosilane.

This diisopropylaminochlorosilane solution was added to a 2000 mL flask set with a thermometer, a cooling tube, and a motor stirrer, and a nitrogen-substituted 2000 mL flask, and cooled to 0°C by an immersion cooler using acetone as a refrigerant. Dimethylamine 45.08 g (1.0 mol) was slowly blown in over 4 hours while keeping the temperature at 0°C and stirring. After that, amine hydrochloride produced by filtration under reduced pressure in a nitrogen-substituted glove box removed the main solid, thereby obtaining a hexane solution containing diisopropylaminodimethylaminosilane.

The crude diisopropylaminodimethylaminosilane solution was distilled under atmospheric pressure at an internal temperature of 80°C to remove hexane from the crude diisopropylaminodimethylaminosilane solution, and further, using a distillation column, at an inner temperature of 90°C and 10 Torr. The final product was obtained with high purity by distillation under reduced pressure.

GC analysis after distillation confirmed that 28.0 g (yield 32%) of aminosilane compounds were obtained with a purity of 96.1 area%. The obtained aminosilane compound was identified by ¹ H-NMR and GC-MS. The attribution of ¹ H-NMR is as follows.

σ (ppm)=1.10 ([( CH ₃ ) ₂ -CH] ₂ -N-, 12H, d, J=7.0Hz), 2.51 (( CH ₃ ) ₂ -N-, 6H, s), 3.18 ([ (CH ₃ ) ₂ - CH ] ₂ -N-, 2H, sep), 4.47 (- SiH ₂ -, 2H, s)

As a result of the ¹ H-NMR and GC-MS, the obtained aminosilane compound is represented by the following formula:

It was identified as diisopropylaminodimethylaminosilane represented by.

<Method for producing a silicon-containing film>

[Example 3: Formation of silicon oxide film using diisopropylamino tertiary aminosilane]

A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 150 to 600°C. The aminosilane composition containing the diisopropylamino tertiary aminosilane and carrier gas obtained in Example 1 was injected for a predetermined time of 1 to 6 seconds, and then adsorbed onto the heated silicon substrate. Subsequently, argon gas was introduced into the apparatus for a predetermined period of 6 to 30 seconds, thereby purging the unadsorbed aminosilane composition and by-products. Thereafter, ozone was injected as a reaction gas at a pressure of 8 Torr for 3 seconds to form an atomic layer of silicon oxide derived from diisopropylamino tertiary aminosilane deposited on the substrate. Subsequently, by introducing argon gas for 30 seconds, unreacted ozone gas and by-products were purged. The above cycle was repeated to obtain a silicon oxide film having a desired thickness.

[Example 4: Formation of silicon oxide film using diisopropylaminodimethylaminosilane]

A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 150 to 600°C. The aminosilane composition containing diisopropylaminodimethylaminosilane and a carrier gas obtained in Example 2 was injected for a predetermined time of 1 to 6 seconds, and adsorbed onto the heated silicon substrate. Subsequently, argon gas was introduced into the apparatus for a predetermined period of 6 to 30 seconds, thereby purging the unadsorbed aminosilane composition and by-products. Thereafter, ozone was injected as a reaction gas at a pressure of 8 Torr for 3 seconds to form an atomic layer of silicon oxide derived from diisopropylaminodimethylaminosilane deposited on the substrate. Subsequently, by introducing argon gas for 30 seconds, unreacted ozone gas and by-products were purged. The above cycle was repeated to obtain a silicon oxide film having a desired thickness.

[Example 5: Formation of silicon nitride film using diisopropylamino tertiary aminosilane]

A silicon substrate was placed in a vacuum device and heated to a predetermined temperature of 100 to 600°C. The aminosilane composition containing diisopropylamino tertiary aminosilane and a carrier gas obtained in Example 1 was injected at a predetermined pressure of 0.05 to 100 Torr, and adsorbed onto the heated silicon substrate. Subsequently, the unadsorbed aminosilane composition and by-products were purged in the apparatus. Thereafter, ammonia was injected as a reaction gas at a pressure of 0.05 to 100 Torr to form an atomic layer of silicon nitride derived from diisopropylamino tertiary aminosilane deposited on the substrate. Subsequently, unreacted ammonia gas and by-products were purged. The above cycle was repeated to obtain a silicon nitride film having a desired thickness.

[Example 6: Formation of silicon nitride film using diisopropylaminodimethylaminosilane]

A silicon substrate was placed in a vacuum device and heated to a predetermined temperature of 100 to 600°C. The aminosilane composition containing diisopropylaminodimethylaminosilane and a carrier gas obtained in Example 2 was injected at a predetermined pressure of 0.05 to 100 Torr and adsorbed onto the heated silicon substrate. Subsequently, the unadsorbed aminosilane composition and by-products were purged in the apparatus. Thereafter, ammonia was injected as a reaction gas at a pressure of 0.05 to 100 Torr to form an atomic layer of silicon nitride derived from diisopropylaminodimethylaminosilane deposited on the substrate. Subsequently, unreacted ammonia gas and by-products were purged. The above cycle was repeated to obtain a silicon nitride film having a desired thickness.

[Comparative Example 1: Formation of silicon-containing film using bisdiethylaminosilane]

A silicon-containing film was formed using bisdiethylaminosilane. A silicon substrate was placed in a vacuum apparatus and heated to a predetermined temperature of 150 to 600°C. An aminosilane composition containing bisdiethylaminosilane and a carrier gas was injected for a predetermined time of 1 to 6 seconds, and then adsorbed onto the heated silicon substrate. Subsequently, the unadsorbed aminosilane composition and by-products were purged into the apparatus by introducing argon gas for a predetermined period of 6 to 90 seconds. Thereafter, ozone was injected as a reaction gas for 3 seconds to form an atomic layer of silicon oxide derived from bisdiethylaminosilane deposited on the substrate. Subsequently, by introducing argon gas for 30 seconds, unreacted ozone gas and by-products were purged. The above cycle was repeated to obtain a silicon oxide film having a desired thickness.

Hereinafter, a specific deposition method is shown in Table 1, and Table 2 shows the relationship between the supply time and deposition rate of the raw material aminosilane at a substrate temperature of 300°C, and Table 3 shows the purge of the raw material aminosilane at a substrate temperature of 300°C. The relationship between time and deposition rate was shown, and in Table 4, the relationship between the substrate temperature and deposition rate was shown. On the other hand, the thickness of the formed layer was measured with an ellipsometer.

As shown in Table 2, the deposition rate of the silicon oxide films prepared in Example 3 and Example 4 became constant at 1 second or more, whereas the silicon oxide film of Comparative Example 1 under the same condition had a deposition rate at 3 seconds or more. It was confirmed that the time until the deposition rate became constant in Examples 3 and 4 was shorter than that of Comparative Example 1.

As shown in Table 3, the silicon oxide films prepared in Examples 3 and 4 had a constant deposition rate at an argon purge time of 20 seconds or more, whereas the silicon oxide film of Comparative Example 1 was deposited at an argon purge time of 60 seconds or more. It was confirmed that the time until the rate became constant and the deposition rate became constant in Examples 3 and 4 was a short time.

As shown in Table 4, the silicon oxide film prepared in Example 3 and Example 4 had a substrate temperature of 250 to 500°C in the temperature range (ALD window) in which ALD film formation was possible, whereas the silicon oxide film of Comparative Example 1 was It could be confirmed that it was 300-550 degreeC. Here, the ALD window is defined as the point at which the deposition rate becomes maximum to the point at which it becomes minimum.

That is, in the case of producing a silicon oxide film by the atomic layer deposition method using the aminosilane compound in the present invention, it is known that the supply time and purge time of the raw material can be shortened, and the film formation temperature can also be lowered. Could

By using the atomic deposition method, it is possible to form a silicon film such as a silicon nitride film or a silicon oxide film, which is ultrathin and without atomic defects, even on a semiconductor substrate or nanowire on which a structure having a high aspect ratio is formed. The aminosilane compound according to the present invention is useful in an atomic deposition method for forming a film at a lower temperature and in a shorter time.

Claims (12)

The following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)
An aminosilane compound represented by. The following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both R ¹ and R ² are isopropyl groups.)
A precursor for forming a silicon-containing film represented by. The method of claim 2,
The precursor, wherein the silicon-containing film is formed by chemical vapor deposition. The method of claim 3,
The chemical vapor growth is an atomic layer deposition, a precursor. The following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both of R ¹ and R ² are isopropyl groups.)
A composition for forming a silicon-containing film comprising a compound represented by. The method of claim 5,
The composition, wherein the silicon-containing film is formed by chemical vapor deposition. The method of claim 6,
The chemical vapor growth is an atomic layer deposition, composition. The following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both of R ¹ and R ² are isopropyl groups.)
As a method for producing an aminosilane compound represented by,
(a) synthesizing an aminochlorosilane compound by adding dichlorosilane and a first amine to a solvent;
(b) a filtration step of removing by-product salts by filtration;
(c) synthesizing an aminosilane compound by adding a second amine to the filtrate; And
(d) distillation step of isolating aminosilane compound by distillation
Containing, the manufacturing method. The method of claim 8,
The first amine in the synthesis step (a) is diisopropylamine, and the aminochlorosilane compound is the following formula (1):

It is an intermediate (1) represented by and the second amine in the synthesis step (c) is
R ¹ R ² NH
(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, but it is not included when both of R ¹ and R ² are isopropyl groups.)
R ¹ R ² NH represented by, the production method. The method of claim 8,
The first amine in the synthesis step (a) is
R ¹ R ² NH
(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both of R ¹ and R ² are isopropyl groups.)
It is an amine compound represented by, and the aminochlorosilane compound is the following formula (2):

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both of R ¹ and R ² are isopropyl groups.)
It is an intermediate (2) represented by, and the second amine in the synthesis step (c) is diisopropylamine. The following formula:

(In the formula, R ¹ and R ² are each independently selected from the group consisting of H, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group and tert-butyl group It represents a substituent to be used, provided that it is not included when both of R ¹ and R ² are isopropyl groups.)
A method for producing a silicon-containing film using an aminosilane compound represented by. The method of claim 11,
A method for producing a silicon-containing film, wherein the silicon-containing film is a silicon oxide film.

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