WO2020017723A1 - Insulating film etchant composition and pattern forming method using same - Google Patents

Abstract

Insulating film etchant compositions according to embodiments of the present invention comprise a phosphoric acid, a silane compound having a hydroxyalkyl group or an equivalent thereof, and extra water. The present invention can passivate a silicon oxide film effectively and suppress gelation and silicon oxide regrowth.

Description

Insulating etching liquid composition and pattern formation method using the same

The present invention relates to an insulating film etching liquid composition and a pattern forming method using the same. More specifically, the present invention relates to an inorganic acid-based insulating film etching solution composition and a pattern forming method using the same.

For example, a thin film transistor (TFT) and various pixel circuits are arranged on a back-plane substrate of an image display device such as a liquid crystal display (LCD) device or an organic light emitting display (OLED) display device. Insulation layers such as an interlayer insulating film, a gate insulating film, a via insulating film, and the like that insulate the conductive structures are formed.

Further, in a semiconductor device such as a memory device, for example, insulating films such as an element isolation film, an interlayer insulating film, a gate insulating film, and the like are formed on a silicon or germanium substrate.

For example, the insulating layers may be deposited to include silicon oxide or silicon nitride to include a silicon oxide layer and a silicon nitride layer.

When the insulating layer is etched to form an insulation pattern, etching may be selectively performed on a specific layer. For example, a selective etching process for the silicon nitride film may be required. In this case, an etchant composition for etching only the silicon nitride film may be used while sufficiently protecting the silicon oxide film.

In addition, even when the selective etching process is performed for a long time under high temperature conditions, it is preferable that the protection performance of the silicon oxide film is continuously maintained.

For example, Korean Patent Publication No. 10-0823461 discloses a composition capable of etching a silicon oxide film and a silicon nitride film together. It is difficult to implement the above-described selective etching process.

One object of the present invention is to provide an insulating film etchant composition having improved etching selectivity and etching uniformity.

One object of the present invention is to provide a pattern forming method using the insulating film etching solution composition.

1. phosphoric acid; Silane compounds having a hydroxyalkyl group or an equivalent thereof; And excess water.

2. In the above 1, wherein the silane compound having a hydroxyalkyl group or its equivalent comprises a plurality of passivation groups, insulating film etching solution composition.

3. In the above 2, wherein the passivation group comprises a hydroxyl group or an alkoxy group, insulating film etching liquid composition.

4. In the above 1, wherein the hydroxyalkyl group is a hydroxy group is substituted on the end of the alkyl group, insulating film etching liquid composition.

5. In the above 1, wherein the silane compound having a hydroxyalkyl group or an equivalent thereof comprises at least one selected from the group consisting of compounds represented by the following formula 1 to 3, insulating film etching liquid composition:

[Formula 1]

In Formula 1, R ¹ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R ² is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, and R ³ is substituted with 1 to 3 carbon atoms Or an unsubstituted alkyl group, a and b are integers from 1 to 3, and (a + b) is an integer of 4 or less)

[Formula 2]

In Formula 2, R ⁴ is hydrogen or a substituted or unsubstituted alkyl group having 1 to ⁵ carbon atoms, R ⁵ is an alkylene group having 1 to 6 carbon atoms, R ⁶ is a halogen group except F, and R ⁷ is carbon number A substituted or unsubstituted alkyl group of 1 to 3, m and n are integers of 1 to 3, and (m + n) is an integer of 4 or less)

[Formula 3]

In Formula 3, R ⁸ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R ⁹ is an alkylene group having 1 to 6 carbon atoms, R ¹⁰ is an alkyl group having 1 to 4 carbon atoms, an alkoxy group or alkoxy An alkyl group, R ¹¹ is a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, x and y are integers of 1 to 3, and (x + y) is an integer of 4 or less).

6. In the above 5, the silane compound having a hydroxyalkyl group or an equivalent thereof is at least one of a, m and x is a compound of Formula 1 to 3, and a, m and x is 3 Including at least one of, the insulating film etching liquid composition.

7. In the above 5, wherein the compound represented by Formula 1 comprises at least one selected from the group consisting of compounds represented by the following formula 1-1 to 1-7, insulating film etchant composition:

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

[Formula 1-6]

.

[Formula 1-7]

.

8. In the above 5, wherein the compound represented by Formula 3 comprises at least one selected from the group consisting of compounds represented by the following formula 3-1 to 3-6, an insulating film etchant composition:

 [Formula 3-1]

[Formula 3-2]

[Formula 3-3]

[Formula 3-4]

[Formula 3-5]

[Formula 3-6]

.

9. In the above 1, wherein the silane compound having a hydroxyalkyl group or an equivalent thereof is included in 0.001 to 10% by weight of the total weight of the composition, insulating film etching solution composition.

10. forming an oxide film and a nitride film on the substrate; And selectively etching the nitride film using the insulating film etchant composition of any one of 1 to 9 above.

11. In the above 10, wherein the oxide film comprises silicon oxide, the nitride film comprises silicon nitride, pattern formation method.

The insulating film etching solution composition according to the embodiments of the present invention may include a silane compound having a phosphoric acid and a hydroxyalkyl group or an equivalent thereof. The gelation phenomenon of the silane compound can be suppressed by the hydroxyalkyl group or an equivalent thereof.

In addition, the hydroxyalkyl group or an equivalent thereof may stabilize the etching by-products of the silicon nitride film, and prevent the etching by-products from regrowing the silicon oxide film.

In some embodiments, the silane compound having a hydroxyalkyl group or an equivalent thereof may include a plurality of passivation groups, and may improve the protective effect of the silicon oxide layer.

The insulating film etching composition according to the exemplary embodiments may be effectively used in the selective etching process of the nitride film to etch the silicon nitride film while suppressing the etching of the silicon oxide film.

1 to 3 are schematic cross-sectional views for describing a method of forming a pattern according to example embodiments.

4 to 6 are schematic cross-sectional views for describing a method of forming a pattern according to example embodiments.

The insulating film etching solution composition of the embodiments of the present invention includes a silane compound having phosphoric acid, a hydroxyalkyl group or an equivalent thereof, and excess water. The silicon oxide film can be passivated effectively, and the gelation phenomenon and silicon oxide regrowth can be suppressed.

Hereinafter, embodiments of the present invention will be described in detail.

As used herein, the term "regrowth" may mean that by-products generated by etching the nitride film form silicon oxide particles or silicon oxide film on the oxide film through a chemical reaction.

As used herein, the term "hydroxyalkyl group or equivalent thereof" refers to a substituent that can be converted to a hydroxyalkyl group and a hydroxyalkyl group. The substituent that can be converted to the hydroxyalkyl group can be converted to a hydroxyalkyl group in the aqueous solution, for example, can be converted to a hydroxyalkyl group in the aqueous solution of phosphoric acid.

<Insulation film etching composition>

The insulating film etching composition according to the exemplary embodiments may include a silane compound having phosphoric acid, a hydroxyalkyl group or an equivalent thereof, and excess water.

The nitride layer etching composition is supplied onto a structure including an oxide layer (eg, silicon oxide layer) and a nitride layer (eg, silicon nitride layer) at the same time to etch only the nitride layer at a high selectivity without substantially damaging the oxide layer. Can be used for

For example, the insulating film etching composition may be used to selectively etch the silicon nitride film in the manufacturing process of the semiconductor device.

Phosphoric acid may be represented, for example, by the chemical formula of H ₃ PO ₄ , and may serve as a main etching component for nitride film etching. In example embodiments, the nitride layer etching composition may include about 80 to about 95 wt% of phosphoric acid by weight percent based on the total weight of the composition.

If the content of phosphoric acid is less than about 80% by weight, the overall etching rate may be lowered. When the content of phosphoric acid exceeds about 95% by weight, the etching rate of not only the nitride film but also the conductive film such as the oxide film or the metal film may increase together, thereby reducing the etching selectivity of the nitride film.

Preferably, the phosphoric acid content may be adjusted to about 80 to 90% by weight in consideration of the etching rate and the selectivity.

The silane compound having the hydroxyalkyl group or an equivalent thereof may mean a compound in which a silicon atom is substituted with a hydroxyalkyl group or an equivalent thereof. The hydroxyalkyl group may mean a substituent in which a hydroxy group is substituted with an alkyl group. Equivalents of hydroxyalkyl groups can be dissociated in aqueous phosphoric acid solution and converted to hydroxy alkyl groups. Thus, a silane compound comprising an equivalent of a hydroxyalkyl group can be converted into a silane compound having a hydroxyalkyl group.

In example embodiments, the hydroxyalkyl group or an equivalent thereof may stabilize a by-product generated as the nitride film is etched. The stabilization may be performed by the interaction of the by-product and the hydroxy group of the hydroxyalkyl group. For example, the by-product may be energetically stabilized as a hydrogen bond is formed between an atom having high electronegativity of the by-product (nitrogen atom) and the hydroxy group. In addition, a silane compound having the hydroxyalkyl group or an equivalent thereof may be stabilized by solvating the byproduct. Therefore, the by-products may be prevented from being modified with silicon oxide and precipitated on the surface of the oxide layer, and the increase in thickness of the silicon oxide layer (regrowth) in the etching process may be prevented.

In addition, since the hydroxy group of the hydroxyalkyl group can interact with (for example, hydrogen bond) the phosphoric acid molecule and the water molecule, it may increase the solubility in the aqueous solution of phosphoric acid. In other words, the phosphoric acid compatibility of the silane compound can be improved. Thus, gelation of the etchant can be more suppressed.

In exemplary embodiments, the hydroxyalkyl group may be a hydroxy group is substituted at the end of the alkyl group. Therefore, sufficient space can be secured between other atoms and atomic groups in the silane compound having the hydroxy group and the hydroxyalkyl group or an equivalent thereof, and the hydroxy group can easily interact with the etching byproduct of the nitride film.

In exemplary embodiments, an equivalent of a hydroxyalkyl group may include an alkylene group and a substituent which may be converted into a hydroxy group, and the substituent which may be converted into a hydroxy group may be substituted at the end of the alkylene group. .

In some embodiments, the silane compound having a hydroxyalkyl group or an equivalent thereof may include a plurality of passivation groups. The passivation group includes, for example, a hydroxy group, an alkoxy group, an amine group or a halogen group, and preferably, may be a hydroxy group or an alkoxy group. The passivation group may form a passivation layer through adsorption or chemical interaction on the silicon oxide film surface. Therefore, in etching the laminate including the oxide film and the nitride film, the oxide film may be protected, and the selective etching of the nitride film may be possible.

In general, an alkoxy group, a halogen group, or the like directly connected to a silicon atom in the silane compound may be dissociated into a silanol group (Si-O-H) in an aqueous solution of phosphoric acid. The silanol group may be condensed with a silanol group in an adjacent silane compound to form a siloxane compound, and gelation of the etchant composition may occur while the condensation continues. The gelation can be deepened as the number of alkoxy groups, halogen groups, etc. directly connected to the silicon atoms increases.

Silane compounds according to exemplary embodiments of the present invention include a hydroxyalkyl group, the hydroxyalkyl group may not be dissociated in the aqueous solution of phosphoric acid. In addition, since the volume of the silane compound having the hydroxyalkyl group or the equivalent thereof is increased by the hydroxyalkyl group or the equivalent thereof, it is difficult for the silanol groups of adjacent silane compounds to approach each other, thereby decreasing the gelation rate. .

In exemplary embodiments, the silane compound having a hydroxyalkyl group or an equivalent thereof may include at least one of compounds represented by the following Chemical Formulas 1 to 3.

[Formula 1]

In formula (1), R ¹ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R ² is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, R ³ is substituted or substituted with 1 to 3 carbon atoms or It is an unsubstituted alkyl group, a and b are an integer of 1 to 3, (a + b) may be an integer of 4 or less.

[Formula 2]

In Formula 2, R ⁴ is hydrogen or a substituted or unsubstituted alkyl group having 1 to ⁵ carbon atoms, R ⁵ is an alkylene group having 1 to 6 carbon atoms, R ⁶ is a halogen group except for F, and R ⁷ is 1 carbon atom It is a substituted or unsubstituted alkyl group of 3 to 3, m and n are an integer of 1 to 3, (m + n) may be an integer of 4 or less.

[Formula 3]

In formula (3), R ⁸ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R ⁹ is an alkylene group having 1 to 6 carbon atoms, R ¹⁰ is an alkyl group having 1 to 4 carbon atoms, an alkoxy group or an alkoxyalkyl group. R ¹¹ is a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, x and y are integers of 1 to 3, and (x + y) may be an integer of 4 or less.

The R ¹ O, R ⁴ O and R ⁸ O groups represent a passivation group of the silane compound, and the R ² OH group represents a hydroxyalkyl group.

R ⁶ is a halogen group excluding fluorine and may be dissociated in an aqueous solution of phosphoric acid to be converted into a hydroxy group. -OCOR ¹⁰ of Formula 3 may be dissociated in an aqueous solution of phosphoric acid to be converted to a hydroxyl group.

When the carbon number of R ¹ , R ⁴ and R ⁸ exceeds 5, the solubility of the silane compound having a hydroxy group alkyl group in the aqueous solution of phosphoric acid may decrease. In addition, the molecular weight and volume of the alcohol by-product generated as the R ¹ O group dissociates in the aqueous solution of phosphoric acid may increase. Therefore, the alcohol by-products may act as a hindrance when the silane compound passivates the oxide layer.

When the carbon number of R ² exceeds 3, the solubility of the silane compound having a hydroxy group alkyl group in the aqueous solution of phosphoric acid may decrease. When the carbon number of R ⁵ and R ⁹ exceeds 6, the solubility of the silane compound having the equivalent of a hydroxy group alkyl group in the aqueous solution of phosphoric acid may decrease.

R <^3> , R <^7> and R <^11> can suppress gelation of a silane compound as an alkyl group.

a, b, m, n, x and y may be integers from 1 to 3. Increasing a, m and x may mean an increase in the passivation group, and may mean an increase in the etching selectivity by the protection of the oxide layer. An increase in b, n, and y may mean an increase in the hydroxyalkyl group, and a nitride layer. This may mean inhibiting oxide regrowth and preventing gelation of the etching solution by stabilization of the etching by-product. Preferably, a, m and x may be 2 or 3 for the selective etching of the nitride film.

In some embodiments, in Formulas 1 to 3, at least one of compounds in which a, m, and x are 2, and at least one of compounds in which a, m and x are 3 may be used together. Therefore, selective etching characteristics, gelation prevention characteristics, and oxide film regrowth prevention characteristics of the nitride film can be more precisely controlled.

In some embodiments, the compound represented by Formula 1 may include at least one selected from the group consisting of compounds represented by Formulas 1-1 to 1-7. By using the compounds represented by the following Chemical Formulas 1-1 to 1-7, it is possible to improve the selective etching ratio of the nitride film, to prevent gelation, and to suppress the regrowth of the oxide film. More preferably, the silane compound which has the hydroxyl group of following formula (1-1) and 1-2 can be used.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

[Formula 1-6]

[Formula 1-7]

In some embodiments, the compound represented by Formula 2 may include a compound represented by Formula 2-1.

[Formula 2-1]

In exemplary embodiments, the compound represented by Formula 3 may include at least one selected from the group consisting of compounds represented by Formulas 3-1 to 3-6.

[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

[Formula 3-4]

[Formula 3-5]

[Formula 3-6]

In the comparative example, it may be considered to use a silane compound (eg, a tetravalent alkoxy silane compound) in which all four bonds of silicon atoms are substituted with passivation groups. Although the tetravalent alkoxy silane compound may exhibit an excellent effect in the passivation of the oxide film, because the gelation phenomenon is remarkably severe, it is difficult to use in the etchant composition alone.

However, according to exemplary embodiments of the present invention, at least one of the four bonds of the silicon atom is replaced with a hydroxyalkyl group or an equivalent thereof, thereby reducing the gelation phenomenon and realizing a regrowth prevention effect of the oxide film. have.

In some embodiments, the insulating film etching composition may include a silane compound having about 0.001 to 1% by weight of the hydroxyalkyl group or an equivalent thereof in the total weight of the composition. When the content of the silane compound having the hydroxyalkyl group or the equivalent thereof is less than about 0.001% by weight, oxide passivation may not be substantially implemented. When the content of the silane compound having the hydroxyalkyl group or the equivalent thereof exceeds about 10% by weight, the etching performance of phosphoric acid may be excessively inhibited.

Preferably, in consideration of the oxide passivation effect and the etching rate, the content of the silane compound having the hydroxyalkyl group or the equivalent thereof may be adjusted to about 0.01 to 5% by weight of the total weight of the composition.

In some embodiments, the insulating film etching composition may not include fluorine ion generating species (eg, fluorine ion salts such as fluoride or ammonium fluoride salts). As a result, the etching damage of the oxide film due to the fluorine component can be prevented.

In some embodiments, the insulating film etching composition may not include a component capable of generating a residue in the etching object, for example, an oxime compound. Accordingly, the silicon nitride film etching efficiency due to phosphoric acid can be improved while protecting the silicon oxide film by the silane compound having the hydroxyalkyl group or the equivalent thereof.

The insulating film etching composition may include excess water (eg, deionized water). For example, the phosphoric acid may be provided in the form of an aqueous solution (eg, 85% phosphoric acid), and the silane compound having the hydroxyalkyl group or an equivalent thereof may be mixed in the amount described above with respect to 100 parts by weight of the aqueous solution of phosphoric acid. have.

In some embodiments, the insulating film etching composition may be substantially composed of the aforementioned phosphate, a silane compound having a hydroxyalkyl group or an equivalent thereof, and excess water. In some embodiments, the insulating film etching composition may include an additional component such as an etching enhancer within a range that does not impair the passivation performance of the silane compound having the hydroxyalkyl group or the equivalent thereof and the etching efficiency of phosphoric acid. .

<Pattern forming method>

1 to 3 are schematic cross-sectional views for describing a method of forming a pattern according to example embodiments.

Referring to FIG. 1, the oxide film 110 and the nitride film 120 may be sequentially formed on the substrate 100.

The substrate 100 may include a semiconductor material such as single crystal silicon, single crystal germanium, or may be formed to include polysilicon.

According to example embodiments, the oxide film 110 may be formed to include silicon oxide. The oxide film 110 may be formed through a chemical vapor deposition (CVD) process, a sputtering process, a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, or the like.

The nitride film 120 may be formed on the oxide film 110. According to example embodiments, the nitride film 120 may be formed through a CVD process, a PVD process, a sputtering process, an ALD process, and the like to include silicon nitride.

Referring to FIG. 2, a photoresist pattern 130 may be formed on the nitride film 120. For example, after the photoresist film is formed on the nitride film 120, a portion of the photoresist film may be removed through a selective exposure process and a developing process.

Accordingly, the photoresist pattern 130 exposing a part of the upper surface of the nitride film 120 may be formed.

Referring to FIG. 3, a wet etching process using the photoresist pattern 130 as an etching mask and using an insulating film etchant composition according to the exemplary embodiments described above may be performed.

Accordingly, the exposed nitride layer 120 may be removed to form the nitride layer pattern 125. As described above, the insulating film etching liquid composition according to the exemplary embodiments may provide a significantly improved oxide passivation by the silane compound having a hydroxyalkyl group or an equivalent thereof, and may suppress regrowth of the oxide film. Accordingly, the surface of the oxide film 110 may be substantially etched or damaged, or regrowth may not occur, and only the nitride film 120 may be selectively etched.

For the efficiency of the etching process, the temperature of the etchant composition may be heated to about 150 ℃ or more. Since the silane compound having the hydroxyalkyl group or the equivalent thereof is stable even at a high temperature, the initial etching rate and passivation performance can be maintained uniformly.

The photoresist pattern 130 may then be removed through a strip process and / or an ashing process.

As shown in FIGS. 1 to 3, the nitride film 120 may be partially etched, but the nitride film 120 may be entirely removed using the etchant composition. Even in this case, the entire upper surface of the oxide film 110 may be passivated entirely by a silane compound having a hydroxyalkyl group or an equivalent thereof to be protected from etching damage.

4 to 6 are schematic cross-sectional views for describing a method of forming a pattern according to example embodiments.

Referring to FIG. 4, the plurality of oxide films 210 and the plurality of nitride films 220 may be alternately repeatedly stacked on the substrate 200.

Referring to FIG. 5, a through pattern 230 penetrating the oxide layers 210 and the nitride layers 220 may be formed. For example, after the oxide layers 210 and the nitride layers 220 are etched together through dry etching to form an opening, the through pattern 230 may be formed by filling a filling material in the openings. The through pattern 230 may include a semiconductor material such as polysilicon or a conductive material such as a metal.

Referring to FIG. 6, the nitride layers 220 may be selectively removed using the etchant composition according to the exemplary embodiments described above.

Accordingly, the oxide layers 210 may remain on the sidewall of the through pattern 230, and the gaps 240 may be defined by the space from which the nitride layers 220 are removed. The gaps 240 may be filled with a conductive film, for example, a metal film. The oxide layers 210 may be passivated entirely by a silane compound having a hydroxyalkyl group or an equivalent thereof during the etching process to be protected from etching damage and maintain thickness and shape.

The above-described pattern forming method is exemplary, and the insulating film etching composition according to the embodiments of the present invention may be used to form various insulating structures (eg, gate insulating film, barrier film, device isolation film, etc.) included in a semiconductor device or a display device. Can be applied for

Hereinafter, experimental examples including specific examples and comparative examples are provided to help the understanding of the present invention, but these are merely illustrative of the present invention and are not intended to limit the appended claims, and the scope and spirit of the present invention. It is apparent to those skilled in the art that various changes and modifications to the embodiments can be made within the scope, and such variations and modifications are within the scope of the appended claims.

Examples 1-11 and Comparative Examples

In the 85% phosphoric acid aqueous solution, silane compounds having a hydroxyalkyl group or an equivalent thereof shown in Table 1 were mixed at the following weight% based on the total weight of the composition to prepare the etching liquid compositions of Examples and Comparative Examples.

division	Silane compound	content
Example 1	Formula 1-1	0.1
Example 2	Formula 1-2	0.1
Example 3	Formula 1-4	0.1
Example 4	Formula 1-5	One
Example 5	Formula 1-7	One
Example 6	Formula 2-1	0.1
Example 7	Formula 3-1	0.1
Example 8	Formula 3-2	0.1
Example 9	Formula 3-3	0.1
Example 10	Formula 3-4	One
Example 11	Formula 3-6	One
Comparative Example 1	Formula 4	0.1
Comparative Example 2	Formula 5	0.1
Comparative Example 3	Formula 6	0.1

[Formula 4]

[Formula 5]

[Formula 6]

Examples 12-15

Etching liquid compositions of Examples 12 to 15 were prepared by mixing the compound of Formula 1-2 and the compound of Formula 1-5 in an aqueous solution of 85% phosphoric acid by weight% of Table 2 below.

division	Compound of formula 1-2	Compound of Formula 1-5
Example 12	0.04	0.06
Example 13	0.05	0.05
Example 14	0.07	0.03
Example 15	0.09	0.01

Experimental Example

(1) gelation prevention evaluation

1 g of the silane compound of Examples and Comparative Examples was added to 100 g of an aqueous 85% phosphoric acid solution, and then stirred for 1 minute at room temperature, and then evaluated for phase separation (gelling) when left at room temperature for 1 minute.

○: not gelated

Δ: instantaneously gelled and then dissolved again

×: not gelled again after gelling

(2) silicon oxide (SiO) ₂ ) Etch Suppression Assessment

A silicon oxide film (SiO ₂ ) 400 mm thick wafer was cut into a size of ² × ² cm ² to prepare a sample, and the sample was immersed for 3600 seconds at a temperature of 160 ° C. in the compositions of Examples and Comparative Examples described in Table 2. Thereafter, after washing and drying with deionized water (DIW), the film thickness before and after etching was measured using an ellipsometer to measure the amount of etch and evaluated according to the following criteria.

◎: 4 Hz or less

○: more than 4 Å 8 Å or less

(Triangle | delta): More than 8 Hz and less than 12 Hz

×: more than 12 mm

(3) oxide film regrowth evaluation

A sample was prepared by cutting a silicon nitride film (SiN) 5000 mm thick wafer into a size of ⁴ × ⁵ cm ² , and the sample was immersed in a composition of Examples and Comparative Examples described in Table 2 at a temperature of 160 ° C. for 3600 seconds. Thereafter, the nitride film reacted with the composition to remove the etched wafer, and a 400 mm thick wafer of silicon oxide film (SiO ₂ ) was cut into a size of ² × ² cm ² to prepare a sample, and the sample was immersed at a temperature of 160 ° C. for 3600 seconds. Then, after washing and drying with deionized water (DIW), the film thickness before and after etching is measured with an ellipsometer to measure the time point (number of nitride films) after the etching becomes thicker than before etching. Evaluated.

◎: Regrowth after 20 or more silicon nitride films

(Circle): Regrowth after 10 or more silicon nitride films and less than 20 sheets

(Triangle | delta): Regrowth after processing 5 or more silicon nitride films and less than 10 sheets

X: Regrowth after processing less than 5 silicon nitride films

The evaluation results are shown in Table 3 below.

	Gelation prevention	SiO etch suppression	Silicon oxide regrowth suppression
Example 1	○	○	○
Example 2	○	○	○
Example 3	○	○	○
Example 4	○	△	◎
Example 5	△	△	○
Example 6	○	○	○
Example 7	○	○	○
Example 8	○	○	○
Example 9	○	○	○
Example 10	○	△	○
Example 11	○	△	◎
Example 12	○	△	○
Example 13	○	△	○
Example 14	○	○	○
Example 15	○	○	○
Comparative Example 1	×	○	×
Comparative Example 2	×	○	×
Comparative Example 3	×	○	×

Referring to Table 3, in the case of using the silane compound having a hydroxyalkyl group or an equivalent thereof, the gelation of the etching solution and the regrowth of the silicon oxide film were effectively suppressed while maintaining the oxide passivation effect at a similar level as compared with the comparative example.

In addition, when the silane compound including the passivation group and the hydroxyalkyl group in a 3: 1 mixture and the silane compound containing the passivation group and the hydroxyalkyl group in a 2: 2 mixture are used, the effect of preventing gelation and inhibiting the regrowth of the oxide film is improved. When the silane compound including the hydroxyalkyl group 3: 1 and the silane compound including the passivation group and the hydroxyalkyl group 2: 2 in a weight ratio of 9: 1 to 5: 5 were used, the effect of preventing gelation and inhibiting regrowth of the oxide film was improved.

Claims (11)

1. Phosphoric acid;

   Silane compounds having a hydroxyalkyl group or an equivalent thereof; And

   An insulating film etching liquid composition comprising excess water.
2. The insulating film etchant composition of claim 1, wherein the silane compound having a hydroxyalkyl group or an equivalent thereof comprises a plurality of passivation groups.
3. The insulating film etching liquid composition of claim 2, wherein the passivation group comprises a hydroxy group or an alkoxy group.
4. The etching solution composition of claim 1, wherein the hydroxyalkyl group is a hydroxy group substituted at the terminal of the alkyl group.
5. The etch compound of claim 1, wherein the silane compound having a hydroxyalkyl group or an equivalent thereof comprises at least one selected from the group consisting of compounds represented by Formulas 1 to 3 below:

   [Formula 1]

   

   In Formula 1, R ¹ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R ² is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, and R ³ is substituted with 1 to 3 carbon atoms Or an unsubstituted alkyl group, a and b are integers from 1 to 3, and (a + b) is an integer of 4 or less)

   [Formula 2]

   

   In Formula 2, R ⁴ is hydrogen or a substituted or unsubstituted alkyl group having 1 to ⁵ carbon atoms, R ⁵ is an alkylene group having 1 to 6 carbon atoms, R ⁶ is a halogen group except F, and R ⁷ is carbon number A substituted or unsubstituted alkyl group of 1 to 3, m and n are integers of 1 to 3, and (m + n) is an integer of 4 or less)

   [Formula 3]

   

   In Formula 3, R ⁸ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R ⁹ is an alkylene group having 1 to 6 carbon atoms, R ¹⁰ is an alkyl group having 1 to 4 carbon atoms, an alkoxy group or alkoxy An alkyl group, R ¹¹ is a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, x and y are integers of 1 to 3, and (x + y) is an integer of 4 or less).
6. The method of claim 5, wherein the silane compound having a hydroxyalkyl group or an equivalent thereof is at least one of a compound in which a, m and x are 2 in Formulas 1 to 3, and at least one of a compound in which a, m and x are 3. Comprising one, insulating film etching solution composition.
7. The method of claim 5, wherein the compound represented by Formula 1 comprises at least one selected from the group consisting of compounds represented by Formulas 1-1 to 1-7 below, insulating film etching solution composition:

   [Formula 1-1]

   

   [Formula 1-2]

   

   [Formula 1-3]

   

   [Formula 1-4]

   

   [Formula 1-5]

   

   [Formula 1-6]

   

   [Formula 1-7]

   

   .
8. The method of claim 5, wherein the compound represented by Formula 3 comprises at least one selected from the group consisting of compounds represented by the following formulas 3-1 to 3-6, an insulating film etchant composition:

   [Formula 3-1]

   

   [Formula 3-2]

   

   [Formula 3-3]

   

   [Formula 3-4]

   

   [Formula 3-5]

   

   [Formula 3-6]

   

   .
9. The etch compound of claim 1, wherein the silane compound having a hydroxyalkyl group or an equivalent thereof is included in an amount of 0.001 to 10% by weight based on the total weight of the composition.
10. Forming an oxide film and a nitride film on the substrate; And

    Selectively etching the nitride film using the insulating film etchant composition according to any one of claims 1 to 9.
11. The method of claim 10, wherein the oxide film comprises silicon oxide and the nitride film comprises silicon nitride.

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