KR20190075670A - Etching composition for silicon nitride layer - Google Patents

Abstract

The present invention relates to a silicon nitride film etching composition which can selectively etch a silicon nitride film in comparison with a silicon oxide film, has an excellent etching selection ratio, and has an excellent effect of substantially no change in an etching rate and the etching selection ratio for the silicon nitride film, even if the use time of the composition is increased or the composition is repeatedly used. In addition, the silicon nitride film etching composition comprises: a compound represented by chemical formula 1; phosphoric acid; and water.

Description

[0001] The present invention relates to an etching composition for a silicon nitride layer,

The present invention relates to a silicon nitride film etching composition, and more particularly, to a composition capable of selectively etching a silicon nitride film as compared to a silicon oxide film.

The silicon oxide film (SiO ₂ ) and the silicon nitride film (SiN _x ) are typical insulating films used in semiconductor manufacturing processes. They may be used alone, or alternatively, one or more silicon oxide films and one or more silicon nitride films may be alternately laminated. The silicon oxide film and the silicon nitride film are also used as a hard mask for forming a conductive pattern such as a metal wiring.

형태로 변화하는데, 이중 일부 해리되어 실리콘 이온의 형태로 용액 상에 존재하게 되고, 르 샤틀리에의 원리에 의해 식각 조성물에서 실리콘 이온의 농도가 증가하여 실리콘 질화막의 식각속도를 현저하게 감소시키는 문제가 있다.Conventionally, phosphoric acid is used to remove silicon nitride film in a semiconductor manufacturing process. However, phosphoric acid may be converted to pyrophosphoric acid or various types of polyacic acid at high temperature, Deionized water must be supplied because it affects the etch rate of nitride and oxide films by Autoprotolysis. However, even if the amount of pure water supplied is slightly changed, defects can be caused in the removal of the silicon nitride film, and phosphoric acid itself is corrosive as a strong acid, which makes handling difficult. In addition, the silicon nitride film reacts with phosphoric acid

Which is partially dissociated and is present in the form of a solution in the form of silicon ions, and the concentration of silicon ions in the etching composition is increased by the principle of Le Chatelier, thereby remarkably reducing the etching rate of the silicon nitride film .

Various studies have been conducted to solve these problems, and the research can be classified into three types.

First, it is a technique to increase the etching rate of the silicon nitride film. Specifically, an etching method has been proposed in which phosphoric acid is heated to obtain polyphosphoric acid and then etched at 100 DEG C or higher to increase the selectivity. However, it has not been proved that the selectivity of the polyphosphoric acid is improved by the stability and the crystal structure. It is difficult to quantify the concentration of polyphosphoric acid and it is difficult to control the process temperature due to excessive heat generation during hydration. Further, since the etching rate of the silicon oxide film also increases, it is not preferable because it is difficult to apply to a fine process.

Second, it is a technique to reduce the etching rate of the silicon oxide film. Specifically, an etching solution capable of selectively etching a silicon nitride film by adding sulfuric acid, an oxidizing agent, or the like to phosphoric acid has been proposed. However, when sulfuric acid is added, it is difficult to improve the selectivity to be desired by decreasing the etching rate of the silicon nitride film as well as the silicon oxide film, and the production efficiency is lowered.

Third, it is a technique of adding a fluorine compound. Specifically, an etching method for improving a selectivity to a silicon nitride film by adding a small amount of nitric acid and hydrofluoric acid to phosphoric acid has been proposed. However, there is a problem that the etching rate of the silicon oxide film is increased due to addition of hydrofluoric acid. In addition, an etching solution capable of selectively etching a silicon nitride film by adding a silicon fluoride has been proposed, but this has a problem that the lifetime of the etching solution is very short and the compatibility with the additive is poor.

As described above, various attempts have been made to improve the etch rate and selectivity of the silicon nitride film. However, all of them have caused an undesirable problem in long-term use due to particles on the surface of the wafer as the treatment time increases.

Particularly, when the etching composition is repeatedly used for etching treatment or when the treatment time is increased, there is a fatal problem that affects the silicon oxide film and causes abnormal growth of the silicon oxide film.

Therefore, it is necessary to develop a new etching solution which can overcome the above problems.

The present inventors have recognized the limitations of the prior art and deepen their research. As a result, the inventors have found that silicon nitride films can be more selectively etched than silicon oxide films, and etching selectivity for silicon nitride films is not affected even for long- In particular, does not cause particle problems, and in particular, does not cause abnormal growth of the silicon oxide film.

Korea Patent Publication No. 2012-0077676

An object of the present invention is to provide a silicon nitride film etching composition excellent in stability that can prevent or minimize occurrence of abnormal growth of a silicon oxide film even when the processing time is increased or repeatedly used.

It is an object of the present invention to provide a silicon nitride film etching composition capable of selectively etching a silicon nitride film compared to a silicon oxide film and remarkably improving the etching selectivity.

It is also an object of the present invention to provide a stable silicon nitride film etching composition which is substantially free of change in etch rate and etch selectivity with respect to a silicon nitride film even when the processing time is increased or repeatedly used.

It is another object of the present invention to provide a silicon nitride film etching composition which minimizes damage to other films existing around the silicon oxide film in the semiconductor manufacturing process and has no problems such as generation of particles affecting semiconductor device characteristics .

The silicon nitride film etching composition according to the present invention comprises a compound represented by the following general formula (1), phosphoric acid and water.

[Chemical Formula 1]

In Formula 1, n is an integer of 0 to 10; X ₁ to X ₃ independently of one another are (C ₁ -C 7) alkylene; R ₁ to R ₆ independently of one another are selected from the group consisting of halogen, hydroxy, (C 1 -C 20) alkyl, (C 1 -C 20) alkoxy, (C 2 -C 20) alkenyl, Amino and amino (C1-C20) alkoxy; R ₇ and R ₈ are independently selected from hydrogen, (C 1 -C 20) alkyl, (C 2 -C 20) alkenyl, hydroxy (C 1 -C 20) alkyl and amino (C 1 -C 20) alkyl.

In the silicon nitride film etching composition of the present invention, R ₁ to R ₆ independently represent halogen, hydroxy, (C ₁ -C ₇ ) alkyl, (C 1 -C 7) alkoxy, (C 2 -C 7) (C1-C7) alkyl, (C1-C7) alkylamino and amino (C1-C7) alkoxy; R ₇ and R ₈ independently from each other may be selected from hydrogen, (C 1 -C ₇ ) alkyl, (C 2 -C ₇ ) alkenyl, hydroxy (C 1 -C 7) alkyl and amino (C 1 -C 7) alkyl.

In the silicon nitride film etching composition of the present invention, R ₁ to R ₆ are independently selected from the group consisting of (C ₁ -C ₇ ) alkyl, (C 1 -C 7) alkoxy, (C 2 -C 7) (C1-C7) alkyl, (C1-C7) alkylamino and amino (C1-C7) alkoxy.

Silicon nitride etching composition in accordance with one embodiment of the present invention is the Formula _1, R 1 is (C1-C7) may be alkoxy, R ₂ to R ₆ are independently (C1-C7) alkyl or (C1-C7 one another ) Alkoxy. ≪ / RTI >

In the silicon nitride film etching composition according to an embodiment of the present invention, n may be 0 to 4 in the general formula (1); X ₁ to X ₃ may independently be (C ₁ -C 5) alkylene.

In the silicon nitride film etching composition according to an embodiment of the present invention, n may be 0 or 1 in the general formula (1); R ₁ to R ₆ independently of one another can be (C 1 -C 4) alkyl or (C 1 -C 4) alkoxy.

In the silicon nitride film etching composition according to an embodiment of the present invention, the compound represented by Formula 1 may be represented by the following compounds.

The silicon nitride film etching composition according to an example of the present invention can satisfy the etching selectivity ratio of the following relational expression (1). In the following relational expression (1), E _SiNx is the etching rate of the silicon nitride film, and E _SiO2 is the etching rate of the silicon oxide film.

[Relation 1]

200? E _SiNx / E _SiO2

The etching rate reduction rate of the silicon nitride film etching composition according to an embodiment of the present invention after the repeated etching process can satisfy the following relational expression (5). In the following relational expression 5 _,? ERD _SiNx is the etching rate reduction rate versus the initial etching rate for the silicon nitride film, and? ERD _SiO2 is the etching rate reduction rate versus the initial etching rate for the silicon oxide film.

[Equation 5]

? ERD _SiNx ? 0.7%

The etching rate of the silicon nitride film according to an exemplary embodiment of the present invention may be 30 to 250 Å / min.

The silicon nitride film etching composition according to the present invention can be applied to a method of manufacturing a semiconductor device including an etching process using the same.

The silicon nitride film etching composition according to the present invention has an excellent stability that prevents or minimizes the occurrence of abnormal growth of the silicon oxide film even when the processing time is increased or repeatedly used.

The silicon nitride film forming composition according to the present invention can selectively etch the silicon nitride film compared to the silicon oxide film, and the etching selectivity ratio thereof is remarkably excellent.

The silicon nitride film etching composition according to the present invention has an excellent effect substantially without changing the etch rate and etch selectivity to the silicon nitride film even when the processing time is increased or repeatedly used.

The silicon nitride film etching composition according to the present invention minimizes damage to other films existing around the silicon oxide film when used in a semiconductor manufacturing process and has advantages such as generation of particles affecting semiconductor device characteristics .

Even if the effects are not explicitly mentioned in the present invention, the effects described in the specification anticipated by the technical features of the present invention and their inherent effects are treated as described in the specification of the present invention.

Hereinafter, the silicon nitride film etching composition according to the present invention will be described in detail.

It will be apparent to those skilled in the art that the technical and scientific terms used herein may have other meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. Descriptions of the blurred notice function and configuration are omitted.

The singular forms of the terms used in the present invention can be interpreted to include plural forms unless otherwise indicated.

Unless specifically stated in the present invention, the unit of% used unclearly means% by weight.

The silicon nitride film etching composition according to the present invention comprises a compound represented by the following general formula (1), phosphoric acid and water.

[Chemical Formula 1]

In Formula 1, n is an integer of 0 to 10; X ₁ to X ₃ independently of one another are (C ₁ -C 7) alkylene; R ₁ to R ₆ independently of one another are selected from the group consisting of halogen, hydroxy, (C 1 -C 20) alkyl, (C 1 -C 20) alkoxy, (C 2 -C 20) alkenyl, Amino and amino (C1-C20) alkoxy; R ₇ and R ₈ are independently selected from hydrogen, (C 1 -C 20) alkyl, (C 2 -C 20) alkenyl, hydroxy (C 1 -C 20) alkyl and amino (C 1 -C 20) alkyl.

If this is the case, the silicon nitride film can be selectively etched with respect to the silicon oxide film, and the etching selectivity ratio is remarkably excellent. In addition, although the etching treatment time is increased or the composition can be repeatedly used for the etching treatment, there is an excellent effect that the change of the etching rate and the etching selectivity to the silicon nitride film is very low, and the occurrence of abnormal growth of the silicon oxide film is prevented or minimized, This has an excellent effect.

In Formula 1, n is an integer of 0 to 10, preferably 0 to 4, more preferably 0 to 2, and most preferably 0 or 1. As a preferable example, when n is 1 or more, the problem of abnormal growth of the silicon oxide film depending on cases when etching is compared with the case where n is 0 can be further prevented. However, this is a preferred example, and the present invention is not limited thereto.

In the above formula (1), X ₁ to X ₃ are each independently (C ₁ -C 20) alkylene, preferably (C 1 -C 7) alkylene, more preferably (C 1 -C 4) alkylene.

The silicon nitride film etching composition according to an embodiment of the present invention is characterized in that R ₁ to R ₆ are independently selected from the group consisting of halogen, hydroxy, (C ₁ -C ₇ ) alkyl, (C 1 -C 7) alkoxy, (C1-C7) alkyl, (C1-C7) alkoxy, amino, (C1-C4) alkoxy, (C2-C4) alkenyl, amino (C1- C4) alkyl, (C1- C4) alkylamino and amino (C1-C4) alkoxy.

In the silicon nitride film etching composition according to the present invention, R ₇ and R ₈ independently represent hydrogen, (C 1 -C ₇ ) alkyl, (C 2 -C ₇ ) alkenyl, (C1-C4) alkyl and amino (C1-C7) alkyl, more preferably hydrogen, (C1- C4) alkyl, -C4) alkyl. ≪ / RTI >

In the silicon nitride film etching composition according to an embodiment of the present invention,

More preferably, R ₁ to R ₆ independently of one another are (C 1 -C 7) alkyl or (C 1 -C 7) alkoxy, more preferably (C 1 -C 4) alkyl or (C 1 -C 4) alkoxy. However, this is a preferred example for realizing the effect of the present invention, and the present invention should not be construed to be limited thereto.

A silicon nitride composition in accordance with one embodiment of the present invention, in Formula 1, R ₁ is (C1-C7) may be alkoxy, R ₂ to R ₆ are independently (C1-C7) alkyl or (C1-C7 one another ) Alkoxy. ≪ / RTI > However, this is a preferred example, and the present invention is not limited thereto.

In the silicon nitride film composition according to one preferred embodiment of the present invention, n may be 0 to 4, and X ₁ to X ₃ are each independently a (C ₁ -C 5) alkylene, more preferably a -C3) alkylene. However, this is a preferred example, and the present invention is not limited thereto.

The silicon nitride film composition according to a more preferred embodiment of the present invention is characterized in that, in the above formula (1), n may be 0 to 4; X ₁ to X ₃ may independently be (C ₁ -C 5) alkylene; R ₁ to R ₆ independently of one another are selected from the group consisting of halogen, hydroxy, (C ₁ -C ₇ ) alkyl, (C 1 -C 7) alkoxy, (C 2 -C 7) Amino and amino (C1-C7) alkoxy; R ₇ and R ₈ independently from each other may be selected from hydrogen, (C 1 -C ₇ ) alkyl, (C 2 -C ₇ ) alkenyl, hydroxy (C 1 -C 7) alkyl and amino (C 1 -C 7) alkyl. However, this is a preferred example, and the present invention is not limited thereto.

In a silicon nitride film composition according to a further preferred embodiment of the present invention, n may be 0 or 1, and R ₁ to R ₆ may independently of each other be (C 1 -C 4) alkyl or (C 1 -C 4) alkoxy. However, this is a preferred example, and the present invention is not limited thereto.

Preferably, in the silicon nitride film composition according to the present invention, at least one of R ₁ to R ₆ in the above formula (1) is independently selected from the group consisting of halogen, hydroxy, (C 1 -C 7) alkoxy, Amino (C1-C7) alkoxy. When at least one or more of R ₁ to R ₆ , more preferably two or more of R ₁ to R ₆ , are selected independently of one another from among hydroxy, alkoxy, alkylamino and aminoalkoxy, these functional groups are hydrolyzed As a result, the etch selectivity of the silicon nitride film to the silicon oxide film can be remarkably improved. As a specific example thereof, the compound represented by Formula 1 may be selected from the following compounds, but it is a preferred example, and the present invention is not limited thereto.

In the silicon nitride film composition according to one preferred embodiment of the present invention, the compound represented by Formula 1 may be represented by the following compounds. However, it should be understood that the present invention is not limited thereto.

The halogens described in the present invention may be selected from halogen such as F, Cl, Br, I, and the like, although the present invention is not limited thereto.

The 'alkyl' or 'alkyl group' described in the present invention means a monovalent hydrocarbon chain containing carbon and hydrogen, and may be substituted by nitrogen, oxygen, sulfur or a halogen atom. Such hydrocarbon chains may be branched or straight, and may be straight-chain. Examples of non-limiting alkyl, the alkyl group is _{-CH 3, -C 2 H 5,} -C 3 H 7, -CH (CH 3) 2, -C 4 H 9, -CH 2 -CH (CH 3) 2, _{-CH (CH 3) -C 2 H} 5, -C (CH 3) 3, -C 5 H 11, -CH (CH 3) -C 3 H 7, -CH 2 -CH (CH 3) -C 2 _{H 5, -CH (CH 3)} -CH (CH 3) 2, -C (CH 3) 2 -C 2 H 5, -CH 2 -C (CH 3) 3, -CH (C 2 H 5) 2 _{, -C 2 H 4 -CH (CH} 3) 2, -C 6 H 13, -C 3 H 6 -CH (CH 3) 2, -C 2 H 4 -CH (CH 3) -C 2 H 5, _{-CH (CH 3) -C 4 H} 9, -CH 2 -CH (CH 3) -C 3 H 7, -CH (CH 3) -CH 2 -CH (CH 3) 2, -CH (CH 3) _{-CH (CH 3) -C 2 H} 5, -CH 2 -CH (CH 3) -CH (CH 3) 2, -CH 2 -C (CH 3) 2-C 2 H 5, -C (CH 3 _{) 2-C 3 H 7,} -C (CH 3) 2 -CH (CH 3) 2, -C 2 H 4 -C (CH 3) 3, -CH 2 -CH (C 2 H 5) 2 , and CH _{(CH 3) -C (CH 3} ) _3, but may be exemplified, and thus do not limit the present invention. FIG.

The 'alkoxy' or 'alkoxy group' described in the present invention may be represented by the following compounds. In which R can be (C1-C20) alkyl, preferably (C1-C7) alkyl.

Non-limiting examples thereof include methoxy, ethoxy, propoxy, butoxy and the like, but the present invention is not limited thereto.

The term "alkenyl" or "alkenyl group" used in the present invention means a monovalent hydrocarbon chain containing carbon and hydrogen and containing at least one double bond in the chain, which is substituted by nitrogen, oxygen, sulfur or halogen atom It is possible. Such hydrocarbon chains may be branched or straight, and may be straight-chain. Examples of a non-limiting alkenyl or alkenyl group include -CH = CH ₂ , -CH ₂ -CH = CH ₂ , -C (CH ₃ ) = CH ₂ , -CH═CH-CH ₃ , -C ₂ H ₄ - _{CH = CH 2, -CH 2 -CH} = CH-CH 3, -CH = CH-C 2 H 5, -CH 2 -C (CH 3) = CH 2, -CH (CH 3) -CH = CH, _{-CH = C (CH 3) 2} , -C (CH 3) = CH-CH 3, -CH = CH-CH = CH 2, -C 3 H 6 -CH = CH 2, -C 2 H 4 -CH _{= CH-CH 3, -CH 2} -CH = CH-C 2 H 5, -CH = CH-C 3 H 7, -CH 2 -CH = CH-CH = CH 2, -CH = CH-CH = CH _{-CH 3, -CH = CH-CH} 2- CH = CH 2, -C (CH 3) = CH-CH = CH 2, -CH = C (CH 3) -CH = CH 2, -CH = CH- _{C (CH 3) = CH 2} , -C 2 H 4 -C (CH 3) = CH 2, -CH 2 -CH (CH 3) CH = CH 2, -CH (CH 3) -CH 2 -CH = _{CH 2, -CH 2 -CH = C} (CH 3) 2, -CH 2 -C (CH 3) = CH-CH 3, -CH (CH 3) -CH = CH-CH 3, -CH = CH- _{CH (CH 3) 2, -CH} = C (CH 3) -C 2 H 5, -C (CH 3) = CH-C 2 H 5, -C (CH 3) = C (CH 3) 2, - _{C (CH 3) 2 -CH =} CH 2, -CH (CH 3) -C (CH 3) = CH 2, -C (CH 3) = CH-CH = CH 2, -CH = C (CH 3) _{-CH = CH 2, -CH = CH} -C (CH 3) = CH 2, -C 4 H 8 -CH = CH 2, -C 3 H 6 -CH = CH-CH 3, -C 2 H 4 - _{CH = CH-C 2 H 5} , -CH 2 -CH = CH-C 3 H 7, -CH = CH-C 4 H 9, -C 3 H 6 -C (CH 3) = CH 2, -C 2 H ₄ -CH (CH ₃ ) -CH═CH ₂ , -CH ₂ -CH (CH ₃ ) -CH ₂ -CH═CH ₂ , -CH (CH ₃ ) -C ₂ H ₄ -CH═CH ₂ , -C ₂ H ₄ -CH _{= C (CH 3) 2,} -C 2 H 4 -C (CH 3) = CH-CH 3, -CH 2 -CH (CH 3) -CH = CH-CH 3, -CH (CH 3) -CH _{2 -CH = CH-CH 3,} -CH 2 -CH = CH-CH (CH 3) 2, -CH 2 -CH = C (CH 3) -C 2 H 5, -CH 2 -C (CH 3) _{= CH-C 2 H 5,} -CH (CH 3) -CH = CH-C 2 H 5, -CH = CH-CH 2 -CH (CH 3) 2, -CH = CH-CH (CH 3) - _{C 2 H 5, -CH = C} (CH 3) -C 3 H 7, -C (CH 3) = CH-C 3 H 7, -CH 2 -CH (CH 3) -C (CH 3) = CH _{2, -CH (CH 3) -CH} 2 -C (CH 3) = CH 2, -CH (CH 3) -CH (CH 3) -CH = CH 2, -CH 2 -C (CH 3) 2 - _{CH = CH 2, -C (CH} 3) 2 -CH 2 -CH = CH 2, -CH 2 -C (CH 3) = C (CH 3) 2, -CH (CH 3) -CH = C (CH _{3) 2, -C (CH 3} ) 2 -CH = CH-CH 3, -CH (CH 3) -C (CH 3) = CH-CH 3, -CH = C (CH 3) -CH (CH 3 _{) 2, -C (CH 3)} = CH-CH (CH 3) 2, -C (CH 3) = C (CH 3) -C 2 H 5, -CH = CH-C (CH 3) 3, - _{C (CH 3) 2 -C (} CH 3) = CH 2, -CH (C 2 H 5) -C (CH 3) = CH 2, -C (CH 3) (C 2 H 5) -CH = CH _{2, -CH (CH 3) -C} (C 2 H 5) = CH 2, -CH 2 -C (C 3 H 7) = CH 2, -CH 2 -C (C 2 H 5) = CH-CH _{3, -CH (C 2 H 5} ) -CH = CH-CH 3, -C (C 4 H 9) = CH 2, -C (C _{3 H 7) = CH-CH} 3, -C (C 2 H 5) = CH-C 2 H 5, -C (C 2 H 5) = C (CH 3) 2, -C [C (CH 3) ₃ ] = CH ₂ , -C [CH (CH ₃ ) (C ₂ H ₅ )] = CH ₂ , -C [CH ₂ -CH (CH ₃ ) ₂ ] = CH ₂ , -C ₂ H ₄ -CH = _{CH-CH = CH 2, -CH} 2 -CH = CH-CH 2 -CH = CH 2, -CH = CH-C 2 H 4- CH = CH 2, -CH 2 -CH = CH-CH = CH- _{CH 3, -CH = CH-CH} 2 -CH = CH-CH 3, -CH = CH-CH = CH-C 2 H 5, -CH 2 -CH = CH-C (CH 3) = CH 2, - _{CH 2 -CH = C (CH 3} ) -CH = CH 2, -CH 2 -C (CH 3) = CH-CH = CH 2, -CH (CH 3) -CH = CH-CH = CH 2, - CH = CH-CH _2- C (CH ₃ ) ═CH ₂ , -CH═CH-CH (CH ₃ ) -CH═CH ₂ , -CH═C (CH ₃ ) -CH ₂ -CH═CH ₂ , C (CH ₃ ) ═CH-CH ₂ -CH═CH ₂ , -CH═CH-CH═C (CH ₃ ) ₂ , -CH═CH-C (CH ₃ ) ═CH-CH ₃ , _{CH 3) -CH = CH-CH} 3, -C (CH 3) = CH-CH = CH-CH 3, -CH = C (CH 3) -C (CH 3) = CH 2, -C (CH 3 _{) = CH-C (CH 3} ) = CH 2, -C (CH 3) = C (CH 3) -CH = CH 2 and -CH = CH-CH = CH- CH = CH _2, but may be exemplified, The present invention is not limited thereto.

The 'aminoalkyl' or 'aminoalkyl group' described in the present invention means a compound represented by the following formula. In which R can be (C1-C20) alkyl, preferably (C1-C7) alkyl.

Non-limiting examples thereof include NH ₂ -CH ₂ -, NH ₂ -CH ₂ -CH ₂ -, NH ₂ -CH (CH ₃ ) -CH ₂ -, NH ₂ -CH ₂ -CH (CH ₃ ) _{NH 2 -CH 2 -CH 2 -CH 2} -CH 2 -, NH 2 -CH (CH 3) -CH 2 -CH 2 -CH 2 -, NH 2 -CH 2 -CH (CH 3) -CH 2 - , NH ₂ -CH ₂ -CH ₂ -CH (CH ₃ ) -, NH ₂ -CH ₂ -CH ₂ -CH ₂ - and the like, but the present invention is not limited thereto.

The term " alkylamino " or " alkylamino group " used in the present invention means those represented by the following compounds. Wherein R < ₁₁ > and R < ₁₂ > may be independently selected from alkyl and hydrogen, and at least one of R < ₁₁ > and R < ₁₂ > The carbon number of the alkyl may be C1 to C20, preferably C1 to C7. However, it should be understood that the present invention is not limited thereto.

The 'aminoalkoxy' or 'aminoalkoxy group' described in the present invention means those represented by the following compounds. Wherein R is alkylene, and the number of carbon atoms of the alkylene may be C1 to C20, preferably C1 to C7. However, it should be understood that the present invention is not limited thereto.

The "hydroxyalkyl" or "hydroxyalkyl group" described in the present invention means that the compound is represented by the following formula. Here, R in the following compounds may be (C1-C20) alkyl, preferably (C1-C7) alkyl, but this is only a specific example, and the present invention is not limited thereto.

The nitriding film etching composition according to an embodiment of the present invention comprises 0.001 to 5% by weight of the compound represented by Formula 1 and 60 to 98% by weight of phosphoric acid, preferably 0.01 to 3% by weight of the compound and 70 to 95% Preferably from 0.05 to 1% by weight of said compound and from 75 to 90% by weight of phosphoric acid. If this is the case, the formation of particles is effectively suppressed, and the silicon nitride film can be etched with a high etch selectivity with excellent stability even during a high-temperature semiconductor etching process, and even after the repeated etching process, Etch selectivity can be maintained. In addition, abnormal growth of the silicon oxide film can be remarkably suppressed. At this time, the silicon nitride film etching composition contains residual water such that the total weight of the composition is 100% by weight.

When the compound represented by the formula (1) is contained in the composition in an amount of 0.001 to 5% by weight based on the total weight of the composition, the effect of increasing the content of the compound can be maximized and the etching rate for the silicon nitride The probability of a possible problem can be minimized. However, this is a preferred example, and the present invention is not limited thereto.

As a preferred example, when the phosphoric acid is included in the composition in an amount of 60 to 98% by weight based on the total weight of the composition, the probability of occurrence of particles and problems in which the nitride film is not easily removed due to a decrease in the etching rate of the silicon nitride film can be minimized , It is possible to minimize the probability that the etching selectivity ratio is reduced due to the increase of the etching rate for the silicon oxide film. However, this is a preferred example, and the present invention is not limited thereto.

The phosphoric acid serves as a main etching material, and the phosphoric acid serves to accelerate the etching by providing hydrogen ions in the composition.

The water is not particularly limited, but it is preferably deionized water. More preferably, the deionized water for semiconductor processing may have a specific resistance value of 18 MΩ · cm or more. However, this is a preferred example, and the present invention is not limited thereto.

The silicon nitride film etching composition according to an exemplary embodiment of the present invention may further include an ammonium compound. When an ammonium compound is further used, it does not cause particle problems even during long-term treatment, and can more stably maintain the etching rate and etching selectivity for the silicon nitride film and minimize the defect rate that occurs during etching of the semiconductor device A stable silicon nitride film etching composition can be provided. When the ammonium-based compound is further used in the silicon nitride-based etching composition according to the present invention, the amount of the ammonium-based compound to be used is not limited. For example, the ammonium-based compound may be used in an amount of 0.01 to 3% by weight based on the total weight of the composition. However, this is a preferred example, and the present invention is not limited thereto.

Non-limiting examples of the ammonium-based compound include, but are not limited to, ammonium sulfate, ammonium phosphate, ammonium nitrate, ammonium acetate, ammonium bicarbonate, ammonium chloride, and the like.

The silicon nitride film etching composition according to an exemplary embodiment of the present invention may further include any additive conventionally used in the art. The optional additives may include one or more selected from a surfactant, an antioxidant, a corrosion inhibitor, and the like, but various other additives may be used. In this case, optional additives may be used in an amount of 0.01 to 10% by weight, preferably 0.01 to 3% by weight based on the total weight of the composition, but the present invention is not limited thereto.

The silicon nitride film etching composition according to an embodiment of the present invention has an etching selectivity (E _SiNx / E _SiO2 ) of the following relational expression 1, specifically, an etching selectivity (E _SiNx / E _SiO2 ) of the following relational expression 2, the choice of etch ratio (E _SiNx / _SiO2 E), may be to satisfy more preferably etch selectivity (E _SiNx / _SiO2 E) the following relation 4, but not limited to the numerical range. In the following relational expressions 1 to 4, E _SiNx is the etching rate of the silicon nitride film, and E _SiO2 is the etching rate of the silicon oxide film.

[Relation 1]

200? E _SiNx / E _SiO2

[Relation 2]

200? E _SiNx / E _SiO2 ? 2,500

[Relation 3]

300? E _SiNx / E _SiO2 ? 2,250

[Relation 4]

450? E _SiNx / E _SiO2 ? 2,000

The 'etch selectivity ratio (E _SiNx / E _SiO2 )' referred to in the present invention means the ratio of the etching rate (E _SiO2 ) of the silicon oxide film to the etching rate (E _SiNx ) of the silicon nitride film. It also means that the silicon nitride film can be etched more selectively if the etch rate of the silicon oxide film is close to zero or if the etch selectivity ratio is large.

The etching rate reduction rate of the silicon nitride film etching composition according to an exemplary embodiment of the present invention may be such that the etching rate reduction rate after the repeated etching process satisfies the following relational expression 5, specifically the following relational expression 6, and preferably the following relational expression 7, Do not. Herein, in the following relational expressions 5 to 7 _,? ERD _SiNx is the etching rate reduction rate with respect to the initial etching rate for the silicon nitride film.

[Equation 5]

? ERD _SiNx ? 0.7%

[Relation 6]

0.001? ERD _SiNx ? 0.7%

[Relation 7]

0.01? DELTA ERD _SiNx ? 0.5%

That is, even when the silicon nitride film etching composition according to an embodiment of the present invention is used repeatedly, the etching selectivity ratio does not change substantially and the etching selectivity can be maintained very stably, and the etching selectivity can be maintained.

The 'Etch rate drift (ΔERD)' referred to in the present invention means the rate of change of the etching rate with respect to the initial etching rate when the etching process is repeated (twice or more) using the same etching composition. Specifically, the etching rate decrease rate? ERD is calculated by the following equation (1). In the following expression (1), n is a natural number of 2 or more.

[Equation 1]

△ ERD (%) = [1 - {(etch rate when using n times or more) / (etch rate when used once)}] × 100

Since the etch characteristics such as the etching rate tend to decrease as the etching process is repeatedly performed, the rate of decrease is defined as a measure of the etching rate, and the rate of change is interpreted in the same sense.

Also, the silicon nitride film etching composition according to an exemplary embodiment of the present invention may have a change in etching selectivity of 0.5 or less, preferably 0 to 0.4, more preferably 0 to 0.3 after repeated etching. That is, even when it is repeatedly used, there is little change in etch selectivity, which is very stable and advantageous in process efficiency.

The 'change in etch selectivity ratio' referred to in the present invention means the absolute value of the difference between the initial etch selectivity versus etch selectivity when the etch process is repeated two or more times using the same etch composition.

The etching rate for the silicon nitride film may be 30 to 250 Å / min, preferably 40 to 225 Å / min, and more preferably 100 to 200 Å / min .

The silicon nitride film etching composition according to the present invention can selectively etch only the silicon nitride film without substantially causing the etching effect on the silicon oxide film when the silicon nitride film and the silicon oxide film are mixed, The speed is fast, and particles are not caused on the surface of the substrate, so that the problem of defects in manufacturing a semiconductor device can be minimized.

Further, the silicon nitride film etching composition according to the present invention has a high temperature stability, effectively suppressing the problem of etching the silicon oxide film by the phosphoric acid heated at a high temperature, thereby preventing foreign matter from being formed and preventing substrate defects. So that excellent semiconductor device characteristics can be realized.

In addition, the present invention does not substantially affect the silicon oxide film during etching, and more specifically, it is possible to prevent or minimize the abnormal growth of the silicon oxide film during etching, thereby providing a more stable etching composition.

The present invention also provides a method of selectively etching a silicon nitride film to a silicon oxide film using the above-described silicon nitride film etching composition. The etching may be performed according to a method commonly used in the art, and may be performed according to a method well known in the art, for example, an immersion method, a spray method, or the like .

The silicon nitride film etching composition according to the present invention can also be used in a method of manufacturing a semiconductor device. According to the method for fabricating a semiconductor device including the etching process performed using the silicon nitride film etching composition according to the present invention, selective etching of the silicon nitride film is performed when the silicon nitride film and the silicon oxide film are alternately stacked or mixed It is possible. In addition, it is possible to prevent the generation of particles, which have been a problem in the conventional etching process, and to ensure the stability and reliability of the process. At this time, the kind of the semiconductor device is not particularly limited in the present invention.

As described above, the silicon nitride film etching composition according to the present invention selectively etches the silicon nitride film in the silicon oxide film and the silicon nitride film formed on the substrate.

The substrate may be made of various materials such as silicon, quartz, glass, silicon wafer, polymer, metal, and metal oxide, but is not limited thereto. As an example of the polymer substrate, a film substrate such as polyethylene terephthalate, polycarbonate, polyimide, polyethylene naphthalate, cycloolefin polymer, or the like may be used , But is not limited thereto.

The silicon nitride film etching composition according to an embodiment of the present invention may be preferably performed at a high temperature in the etching process. Specifically, the process temperature may be 50 to 300 ° C, preferably 100 to 200 ° C, It can be changed as necessary considering process and other factors.

Therefore, the silicon nitride film etching composition according to the present invention can be efficiently used in various processes requiring selective etching of the silicon nitride film with respect to the silicon oxide film in each etching process.

In addition, according to the etching method using the silicon nitride film etching composition according to the present invention, even though the etching process is repeated, the problem of particles is not caused, so that stable etching can be performed. In addition, it is possible to effectively prevent the silicon oxide film from being unnecessarily or excessively removed or damaged as the silicon nitride film is selectively etched, its speed is fast, and the selectivity to the silicon nitride film is very high.

The 'silicon nitride film' referred to in the present invention may be various silicon nitride films such as SiN films, SiON films, and doped SiN films. As a concept including such silicon nitride films, for example, they are mainly used as insulating films Can be considered as a membrane quality. However, the present invention can be used without limitation as long as it is a technical field for the purpose of selectively etching the silicon nitride film compared to the silicon oxide film.

The 'silicon oxide film' referred to in the present invention is not limited as long as it is a silicon oxide film commonly used in the art. Examples of the silicon oxide film include a spin on dielectric (SOD) film, a high density plasma (HDP) film, (Borosilicate Glass) film, PSG (Polysilazane) film, FSG (Fluorinated Silicate Glass) film, LP-TEOS (Low Pressure Tetra Ethyl Ortho Silicate) film, BPSG (Phospho Silicate Glass) Film, a high temperature oxide (HTO) film, a medium temperature oxide (MTO) film, a USG (undoped silicate glass) film, a SOG (spin on glass) film, an APL ) Film, an ALD (Atomic Layer Deposition) film, a PE-oxide film (Plasma Enhanced oxide), an O3-TEOS (O3-Tetra Ethyl Ortho Silicate) film, and a combination thereof. However, it should be understood that the present invention is not limited thereto.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples. However, the present invention is described in more detail with reference to the following Examples. However, the scope of the present invention is not limited by the following Examples.

The components were mixed at the composition ratios shown in the following Table 1 and stirred at a rate of 500 rpm for 5 minutes at room temperature to prepare a silicon nitride film etching composition. The water content was made such that the total weight of the composition was 100% by weight.

[Examples 2 to 4]

Except that the composition was changed as shown in Table 1 below, in the same manner as in Example 1, thereby preparing respective silicon nitride film etching compositions.

[Comparative Examples 1 to 3]

Except that the compounds were changed as shown in the following Table 1, the silicon nitride film etching compositions were respectively prepared.

Composition and composition ratio Phosphoric acid (wt%) The compound represented by the formula (1) Water (wt%) ingredient Content (wt%) Example 1 85 Si-1 0.05 Balance Example 2 85 Si-1 0.10 Example 3 85 Si-2 0.10 Example 4 85 Si-3 0.10 Example 5 85 Si-4 0.10 Comparative Example 1 85 - - Comparative Example 2 85 B-1 0.10 Comparative Example 3 85 B-2 0.10 Si-1: Bis (3-triethoxysilylpropyl) amine (bis (3-triethoxysilylpropyl) amine)
Si-2: N, N'-bis [(3-trimethoxysilyl) propyl] ethylenediamine (N,
Si-3: bis (methyldiethoxysilylpropyl) amine (Bis (methyldiethoxysilylpropyl) amine)
Si-4: N, N'-bis (2-hydroxyethyl) -N, N'-bis (trimethoxysilylpropyl) ethylenediamine -bis (trimethoxysilylpropyl) ethylenediamine)
B-1: 3-Aminopropylsilanetriol
B-2: N- [3- (trimethoxysilyl) propyl] ethylenediamine (N- [3- (Trimethoxysilyl) propyl] ethylenediamine)

Etching amount and etching rate measurement method of silicon nitride film and silicon oxide film

The etching performance of each of the etching compositions prepared in Examples 1 to 5 and Comparative Examples 1 and 2 was evaluated.

Specifically, a silicon nitride film (SiN film) wafer and a silicon oxide film (LP-TEOS (Low Pressure Tetra Ethyl Ortho Silicate)) wafer were prepared by the same process as the semiconductor manufacturing process by chemical vapor deposition (CVD) .

Before the etching using each of the above etching compositions was started, the thickness before etching was measured using an Ellipsometer (JA WOOLLAM, M-2000U) as a thin film thickness measuring instrument. The wafers were immersed in each of the above etching compositions maintained at an etching temperature of 163 DEG C in a quartz bath for 10 minutes each to conduct an etching process. After the etching was completed, the substrate was cleaned with ultrapure water, and the residual etchant and moisture were completely dried using a drying apparatus to evaluate the etching performance. The results are shown in Table 2 below.

In addition, the etching performance was evaluated by performing 10 batches by repeating the etching process without changing the etching composition in one batch.

The etch rate was calculated by dividing the difference between the thickness before etching and the thickness after etching using an ellipsometer (Ellipsometer, JA WOOLLAM, M-2000U) divided by the etching time (minute). The results are shown in Table 3 below.

Evaluation of Selective Etch Characteristics of Silicon Nitride Films on Silicon Oxide Films

The etching selectivity ratio (etching rate of the silicon nitride film / etching rate of the silicon oxide film) was determined by the ratio of the etching rate of the silicon nitride film to the etching rate of the silicon oxide film, from the measurement results of the etching amount and the etching rate of the silicon nitride film and the silicon oxide film The results are shown in Tables 2 and 3 below.

Process temperature (캜) Etching speed (Å / min) Selectivity (E _SiNx / E _SiO2 ) The nitride film (E _SiNx ) The oxide film (E _SiO2 ) Example 1 163 167.0 0.29 576 Example 2 163 165.1 0.10 1,650 Example 3 163 166.0 0.12 1,383 Example 4 163 168.2 0.33 509 Example 5 163 164.4 0.09 1,822 Comparative Example 1 163 170.2 2.91 58 Comparative Example 2 163 166.0 1.99 83 Comparative Example 3 163 165.3 2.02 82

As shown in Table 2, it can be seen that the etch rate for the nitride film and the etching selectivity for the nitride film relative to the oxide film are significantly superior to the comparative examples in all of the embodiments.

Further, in the case of Example 2 in which a compound satisfying the formula (1) wherein R ₁ to R ₆ are all alkoxy was used, comparison with the case of the example 4 in which a compound satisfying the formula (1) wherein R ₁ and R ₄ are each an alkyl group was used The etch selectivity ratio of the oxide film to the nitride film is more than three times higher than that of the oxide film.

Process temperature (캜) Number of batches Nitride film etching rate (A / min) Etching rate reduction rate of nitride film (%) Oxide film abnormal growth occurrence level (A) Example 1 163 One 167.0 - 0 10 166.5 0.32 0 Example 2 163 One 165.1 - 0 10 164.4 0.40 0 Example 3 163 One 166.1 - 0 10 165.9 0.13 0 Example 4 163 One 168.2 - 0 10 167.8 0.22 0 Example 5 163 One 164.4 - 0 10 163.8 0.35 0 Comparative Example 1 163 One 170.2 - 0 10 161.2 5.3 120 Comparative Example 2 163 One 166.4 - 0 10 159.9 3.9 90 Comparative Example 3 163 One 165.3 - 0 10 160.0 3.2 75

As shown in Table 3, in the comparative examples, abnormal growth of the oxide film occurred, but in all of the examples, the oxide film abnormal growth did not occur, and it was confirmed that the stability after repeated use was remarkably excellent.

As described above, the silicon nitride film etching composition according to the present invention including the compound represented by the general formula (1) not only enables the silicon nitride film to be selectively etched, but also deteriorates the initial etching performance And the stability was excellent, the production efficiency was remarkably increased. In addition, it can be seen that damage to the film of the silicon oxide film is minimized during the etching process, and the generation of particles is prevented, thereby providing a high-quality semiconductor device.

Claims (11)

1. A silicon nitride film etching composition comprising a compound represented by the following formula (1), phosphoric acid and water.
[Chemical Formula 1]

(In the formula 1,
n is an integer from 0 to 10;
X ₁ to X ₃ independently of one another are (C ₁ -C 7) alkylene;
R ₁ to R ₆ independently of one another are selected from the group consisting of halogen, hydroxy, (C 1 -C 20) alkyl, (C 1 -C 20) alkoxy, (C 2 -C 20) alkenyl, Amino and amino (C1-C20) alkoxy;

R ₇ and R ₈ are independently selected from hydrogen, (C 1 -C 20) alkyl, (C 2 -C 20) alkenyl, hydroxy (C 1 -C 20) alkyl and amino (C 1 -C 20) The method according to claim 1,
In Formula 1,
R ₁ to R ₆ independently of one another are selected from the group consisting of halogen, hydroxy, (C ₁ -C ₇ ) alkyl, (C 1 -C 7) alkoxy, (C 2 -C 7) Amino and amino (C1-C7) alkoxy;
R ₇ and R ₈ are independently selected from hydrogen, (C 1 -C ₇ ) alkyl, (C 2 -C ₇ ) alkenyl, hydroxy (C 1 -C 7) alkyl and amino (C 1 -C 7) alkyl. 3. The method of claim 2,
In Formula 1,
R ₁ to R ₆ are independently (C1-C7) alkyl, (C1-C7) alkoxy, (C2-C7) alkenyl, amino (C1-C7) alkyl, (C1-C7) alkylamino, and amino (C1 each other -C7) alkoxy. ≪ / RTI > The method of claim 3,
In Formula 1,
R < ₁ > is (C1-C7)
R ₂ to R ₆ are independently of each other (C 1 -C 7) alkyl or (C 1 -C 7) alkoxy. The method according to claim 1,
In Formula 1,
n is from 0 to 4;
X ₁ to X ₃ are each independently (C ₁ -C 5) alkylene. The method according to claim 1,
In Formula 1,
n is 0 or 1;
R ₁ to R ₆ are independently of each other (C 1 -C 4) alkyl or (C 1 -C 4) alkoxy. The method according to claim 1,
Wherein the compound represented by Formula 1 is selected from the following compounds.

The method according to claim 1,
Wherein the etching selectivity of the silicon nitride film satisfies the following relation (1).
[Relation 1]
200? E _SiNx / E _SiO2
(Where E _SiNx is the etching rate of the silicon nitride film and E _SiO2 is the etching rate of the silicon oxide film in the relational expression 1) The method according to claim 1,
Wherein the etching rate reduction rate after the repetitive etching process satisfies the following relational expression (5).
[Equation 5]
? ERD _SiNx ? 0.7%
(DELTA ERD _SiNx is the reduction rate of the etching rate with respect to the silicon nitride film relative to the initial etching rate, and DELTA ERD _SiO2 is the reduction rate of the etching rate with respect to the initial etching rate with respect to the silicon oxide film) The method according to claim 1,
Wherein the etching rate for the silicon nitride film is 30 to 250 A / min. A method of manufacturing a semiconductor device comprising an etching process using a silicon nitride film etching composition according to any one of claims 1 to 10.