KR102398593B1 - Etching composition for silicon nitride film - Google Patents

Abstract

The present invention minimizes the etch rate of the silicon oxide film, can selectively etch the silicon nitride film, and does not cause changes in the etch rate and etch selectivity of the silicon nitride film and the silicon oxide film even after long-term use and does not cause particle problems. It relates to an etching composition for etching a nitride film.

Description

Etching composition for selective etching of silicon nitride film {ETCHING COMPOSITION FOR SILICON NITRIDE FILM}

In the present invention, in etching the silicon oxide film and the silicon nitride film, the silicon nitride film can be selectively etched compared to the silicon oxide film, and the etch selectivity to the silicon nitride film is not affected even after long-term use, and the etching rate is maintained constant. It relates to an etching composition for wet use that does not cause particle problems.

A silicon oxide film (SiO ₂ ) and a silicon nitride film (SiNx) are representative insulating films used in a semiconductor manufacturing process. These may be used alone, or one or more silicon oxide films and one or more silicon nitride films may be alternately stacked. In addition, 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.

In order to remove the silicon nitride film in the conventional semiconductor manufacturing process, phosphoric acid is used, but the phosphoric acid is continuously concentrated by evaporation of water at a high temperature. Deionized Water) must be continuously supplied. However, even a slight change in the amount of supplied pure water may cause defects in the removal of the silicon nitride film, and phosphoric acid itself is corrosive as a strong acid, so it is difficult to handle. In addition, the silicon nitride film reacts with phosphoric acid to change into H ₂ SiO ₃ form. It dissolves in water to form Si(OH) ₄ , and Si(OH) ₄ combines with other Si(OH) ₄ to form particles or SiO ₂ reduces the etch rate by bonding to the surface of the film. In addition, according to Le Chatelier's principle, as the concentration of the product in the etching composition increases, the etching rate of the silicon nitride layer is significantly reduced.

Various studies have been conducted to solve these problems, and these studies can be broadly classified into three categories.

First, it is a technology that increases the etching speed of the silicon nitride film. For example, an etching method has been proposed to increase the selectivity by heating phosphoric acid to obtain polyphosphoric acid and then etching at 100° C. or higher. However, the effect of improving the selectivity according to the stability and crystal structure of polyphosphoric acid has not been verified. It is difficult to quantify the concentration, and it is difficult to control the process temperature due to excessive heat generation during hydration. In addition, since the etching rate of the silicon oxide film is also increased, it is difficult to apply the silicon oxide film to a fine process, which is not preferable.

Second, it is a technology that slows down the etching rate of the silicon oxide film. As an example, an etching solution capable of selectively etching a silicon nitride film by adding sulfuric acid and an oxidizing agent to phosphoric acid has been proposed, but in the case of adding sulfuric acid, the etching speed of the silicon nitride film as well as the silicon oxide film is slowed down, resulting in a loss in productivity.

Third, it is a technology for adding a fluorine-based compound. As an example, an etching method for obtaining a high selectivity for a silicon nitride film by adding a small amount of nitric acid and hydrofluoric acid to phosphoric acid has been proposed, but this has a problem in that the etching rate of the silicon oxide film is increased due to the addition of hydrofluoric acid. As another example, an etching solution capable of selectively etching a silicon nitride film by adding a silicon-based fluoride has been presented, but this has a problem in that it causes particles on the wafer surface due to excessive silicon addition, and the life of the etching solution is very short and , has problems such as poor compatibility with additives.

Therefore, it is necessary to develop an etchant solution having a new composition that overcomes the above disadvantages.

Accordingly, the present inventor recognized the limitations of the prior art and, as a result of intensifying research, confirmed that by adjusting the content of phosphoric acid and a predetermined nitrogen-containing etch stabilizer, a constant etching rate can be maintained without affecting the selectivity even during long-term use. The present invention was completed.

Korean Patent Publication No. 2012-0077676

An object of the present invention is to provide an etching composition capable of selectively etching a silicon nitride layer compared to a silicon oxide layer.

Another object of the present invention is to provide a stable etching composition in which there is no change in the etching rate and the etching selectivity for the silicon nitride layer even when the treatment time is increased.

Another object of the present invention is to minimize damage to other films existing in the vicinity including the silicon oxide film during the semiconductor manufacturing process, and to etch for silicon nitride film that does not have problems such as generation of particles affecting semiconductor device characteristics. to provide a composition.

The present invention provides an etching composition comprising 30 to 95% by weight of phosphoric acid, 0.005 to 10% by weight of a nitrogen-containing etch stabilizer and the remaining amount of water, based on the total weight of the composition, in order to solve the above problems. The etching composition is characterized in that the silicon nitride layer compared to the silicon oxide layer is selectively etched.

The etching composition according to an embodiment of the present invention may include at least one nitrogen-containing etch stabilizer selected from an amine-based compound, an amide-based compound, a urea-based compound, and an isocyanate-based compound.

The etching composition according to an embodiment of the present invention may further include a silicon-based compound.

The etching composition according to the present invention can selectively remove the silicon nitride layer compared to the silicon oxide layer, minimize damage to the silicon oxide layer, and effectively prevent particle generation, thereby preventing unwanted damage in the etching process.

In addition, the etching composition according to the present invention has excellent storage stability, and can maintain an etch rate and an etch selectivity for a silicon nitride film despite long-term use or storage, and ultimately a semiconductor manufacturing process for selectively etching a silicon nitride film productivity can be improved.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be embodied in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Hereinafter, an etching composition for selective etching of a silicon nitride layer according to the present invention and an etching method using the same will be described in detail.

As used herein, the term “etch selectivity (E _SiNx / E _{SiO 2} )” refers to the ratio of the etch rate (E _{SiO 2} ) of the silicon oxide layer to the etch rate (E _SiNx ) of the silicon nitride layer. In addition, when the etching rate of the silicon oxide layer approaches zero or the etch selectivity is high, it means that the silicon nitride layer can be selectively etched.

As used herein, the term “change in etch selectivity” refers to an absolute value of the difference in etch selectivity compared to initial etch selectivity when the etch process is repeatedly performed two or more times using the same etch composition.

As used herein, the term "Etch rate drift (ΔERD)" refers to a rate of change of the etch rate compared to the initial etch rate when the etch process is repeatedly performed two or more times using the same etch composition. In general, as the etching process is repeatedly performed, the etchability, that is, the etching rate, tends to decrease, so it is defined as a decrease rate, and the rate of change is also interpreted in the same meaning.

The etching composition according to the present invention selects a predetermined nitrogen-containing etch stabilizer and mixes it with phosphoric acid in an appropriate mixing ratio, so that the etching ability by the etchant is not damaged, while minimizing the damage to the silicon oxide film and reducing the generation of particles. can be effectively prevented. Moreover, the etching composition according to the present invention has high stability and can maintain an etching rate and an etching selectivity for a silicon nitride layer for a long time despite an increase in treatment time.

Specifically, the etching composition according to the present invention is characterized in that it contains 30 to 95% by weight of phosphoric acid, 0.005 to 10% by weight of a nitrogen-containing etch stabilizer, and the remaining amount of water, based on the total weight of the composition.

The nitrogen-containing etch stabilizer of the etching composition according to an embodiment of the present invention may be at least one selected from an amine-based compound, an amide-based compound, a urea-based compound, an isocyanate-based compound, and the like.

The nitrogen-containing etch stabilizer stabilizes Si(OH) ₄ generated after the etching process, thereby increasing the etch rate and etch selectivity (E _SiNx / E _SiO2 ) for the silicon nitride film and the silicon oxide film despite the repeated etching process. In terms of maintaining it, it may have at least one or more aliphatic substituents such as alkyl, alkoxy, and alkanol.

In one embodiment, the nitrogen-containing etch stabilizer is an amine-based compound selected from alkylamines, alkanolamines, alkoxyamines and polyvalent ethyleneamines; an amide-based compound selected from N-alkylamide, N-alkyl acetamide, and alkylimide; and isocyanate-based compounds selected from alkyl isocyanates and the like; It may be one or more selected from.

Non-limiting examples of the amine-based compound include primary alkylamines such as methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, and nonylamine; secondary alkylamines such as dimethylamine, diethylamine, dipropylamine, dibutylamine, methylethylamine, methylpropylamine, and methylbutylamine; tertiary alkylamines such as trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, dimethylethylamine, methyldiethylamine, and methyldipropylamine; Monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, aminoethanol, ethylaminoethanol, methylaminoethanol, methyldiethanolamine, dimethylethanolamine, diethylaminoethanol, aminoethylaminoethanol, aminopropanol, aminobutanol , alkanolamines such as dibutanolamine; 2-Methoxyethylamine, 3-methoxypropylamine, (butoxymethyl)diethylamine, (methoxymethyl)diethylamine, (methoxymethyl)dimethylamine, (butoxymethyl)dimethylamine, (isobu Toxymethyl) dimethylamine, (methoxymethyl) diethanolamine, (hydroxyethyloxymethyl) diethylamine, methyl (methoxymethyl) aminoethane, methyl (methoxymethyl) diethanolamine, (hydroxyethyloxy alkoxyamines such as methyl)diethylamine, methyl(methoxymethyl)aminoethane, methyl(methoxymethyl)aminoethanol, methyl(butoxymethyl)aminoethanol, and (aminoethoxy)ethanol; and polyvalent ethylene amines such as ethylenediamine, diethylenetriamine, triethylenetetraamine and tetraethylenepentaamine; and the like, but is not limited thereto.

Non-limiting examples of the amide compound include N-methylformamide, N-ethylformamide, N-propylformamide, N-butylformamide, N-pentylformamide, N-hexylformamide, N-heptyl N-alkyl formamides such as formamide, N-octylformamide, N-nonylformamide, N,N-dimethylformamide, and N,N-diethylformamide; N-alkyl acetamides such as N-methylacetamide and N,N-dimethylacetamide; and alkanamides such as propanamide, butanamide, pentanamide, hexanamide, heptanamide, octanamide, and nonanamide; and the like, but is not limited thereto.

The urea-based compound is urea (urea, CH ₄ N ₂ O); and alkylureas such as N,N-dimethylurea, N,N-diethylurea, N,N,N',N'-tetramethylurea, N,N,N',N'-tetraethylurea; and the like, but is not limited thereto.

Non-limiting examples of the isocyanate-based compound include, but are not limited to, alkyl isocyanates such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, heptyl isocyanate, octyl isocyanate, and nonyl isocyanate.

The etching composition according to an embodiment of the present invention may maintain a constant etch rate and etch selectivity for the silicon nitride layer despite an increase in processing time as the composition ratio is mixed as described above. Moreover, it is possible to minimize particles generated after the etching process. This effect is expected because the nitrogen-containing etch stabilizer stabilizes Si(OH) ₄ generated during etching of the silicon nitride layer through polar bonding such as hydrogen bonding.

Phosphoric acid included in the etching composition according to an embodiment of the present invention serves to selectively etch the silicon nitride layer by providing hydrogen ions in the composition and maintaining high-temperature process conditions.

In addition, the etching composition according to an embodiment of the present invention may include a residual amount of water, and the water is not particularly limited, and is preferably deionized water, more preferably deionized water for semiconductor processing, and has a specific resistance value of 18 It is better to be more than ㏁·cm.

In one embodiment, the etching composition according to an embodiment of the present invention may include preferably 50 to 95% by weight of phosphoric acid, 0.05 to 10% by weight of a nitrogen-containing etch stabilizer, and the remaining amount of water based on the total weight of the composition. there is. In this range, stability in the etching process is maintained and generation of particles can be effectively prevented.

In one embodiment, the etching composition according to an embodiment of the present invention, based on the total weight of the composition, more preferably 70 to 95% by weight of phosphoric acid, 0.05 to 3% by weight of a nitrogen-containing etch stabilizer, and the remaining amount of water. can In this range, stability in a high-temperature etching process of 140 ° C. or higher is maintained to effectively prevent the generation of particles, and the etching rate for the silicon oxide film and the silicon nitride film can be kept constant despite repeated etching processes. .

In the etching composition according to an embodiment of the present invention, the etching rate for the silicon nitride layer may be 30 to 100 Å/min, preferably 40 to 100 Å/min, more preferably 50 to 100 Å/min.

The etching composition according to an embodiment of the present invention has an etch selectivity ratio (E _SiNx / E _SiO2 ) for a silicon nitride film to a silicon oxide film of 3.0 or more, which satisfies the etch rate reduction rate of the following Relations 1 and 2 even after repeated etching processes. can be one

[Relational Expression 1]

△ERD _SiNx ≤ 5%

[Relational Expression 2]

△ERD _SiO2 ≤ 5%

[In Relations 1 and 2,

ΔERD _SiNx is an etch rate decrease rate compared to the initial etch rate for the silicon nitride film;

ΔERD _SiO2 is the rate of decrease in the etch rate compared to the initial etch rate for the silicon oxide layer.]

In this case, when the same etching process is repeatedly performed two or more times using the same etching composition, the reduction rate of the etching rate means a change rate of the etching rate compared to the initial etching rate. In this case, the etching using the etching composition may be performed under the condition of immersing the material to be etched at 157° C. for 10 minutes.

In one embodiment, when a nitrogen-containing etch stabilizer selected from alkylamine, alkanolamine, alkoxyamine, polyvalent ethyleneamine, N-alkylamide, N-alkyl acetamide, alkylimide, alkyl isocyanate, etc. is used, the silicon nitride film It is preferable because the reduction rate of the etch rate can be remarkably reduced to 3% or less.

In the etching composition according to an embodiment of the present invention, the etching selectivity of the silicon nitride layer to the silicon oxide layer (E _SiNx / E _SiO2 ) may be 3.0 or more. Preferably 3.0 or more and 500 or less, more preferably 4.0 or more and 500 or less, and particularly preferably 5.0 or more and 300 or less, but is not limited thereto.

In one embodiment, the etching composition may have a change in etch selectivity of 0.5 or less even after repeated etching processes, preferably 0 to 0.4 or less, and more preferably 0 to 0.3 or less, but is not limited thereto.

In addition, since the etching composition according to an embodiment of the present invention further includes a silicon-based compound, it is possible to remarkably improve the etch selectivity for the silicon nitride layer.

Conventional attempts have been made to increase the etch selectivity of the silicon nitride film compared to the silicon oxide film by using a fluorine-based compound, but not only cause particles on the surface of the substrate, but also the etchability of the etching composition is significantly reduced and the lifespan is reduced. There were problems such as

The etching composition according to the present invention is a non-fluorine-based etching composition, and the stability of the etching ability is secured by the combination of phosphoric acid and a predetermined nitrogen-containing etching stabilizer, and the etching ability does not decrease due to the additional additive and at the same time, additional additives , in particular, it was confirmed that the etching selectivity for the silicon nitride film compared to the silicon oxide film could be remarkably increased according to the combination with the silicon-based compound.

Of course, the silicone-based compound may be used without limitation as long as it does not reduce the etching ability of the etching composition according to the present invention, and in one embodiment, it may be one represented by the following formula (1).

[Formula 1]

Si(OR ¹ ) _{4 - n} (R ² ) _n

[In Formula 1,

R ¹ and R ² are each independently selected from hydrogen and (C1-C3)alkyl;

n is an integer from 0 to 3.]

Non-limiting examples of the silicone-based compound include orthosilicic acid (orthosilicic acid), tetramethylorthosilicate, tetraethylorthosilicate, tetrapropylorthosilicate, and tetraisopropylorthosilicate.

In this case, the silicone-based compound may be included in an amount of 0.01 to 5% by weight based on the total weight of the composition, preferably 0.01 to 3% by weight, and more preferably 0.05 to 1% by weight.

In short, in the etching composition according to an embodiment of the present invention, the phosphoric acid acts as a main etchant, and as it is combined with the above-described predetermined nitrogen-containing etch stabilizer, it is possible to selectively etch the silicon nitride film compared to the silicon oxide film, of course, The stability of the etching composition may be remarkably improved. In addition, despite long-term use, the etch selectivity for the silicon nitride layer compared to the silicon oxide layer can be maintained, so that the silicon nitride layer can be etched at a certain ratio.

In addition, the etching composition according to an embodiment of the present invention can effectively prevent etching defects by minimizing etching residues (eg, particles) generated during etching.

Of course, the etching composition according to an embodiment of the present invention may further include any additives commonly used in the art. In this case, the optional additive may be one or more selected from a chelating agent, an antioxidant, an etch control agent, an organic solvent, and the like.

The present invention provides a method of selectively etching a silicon nitride layer compared to a silicon oxide layer using the etching composition. In this case, the etching method may be performed according to a method commonly used in the art.

In one embodiment, the etching method according to an embodiment of the present invention includes depositing a silicon oxide film on a substrate; depositing a silicon nitride film on the silicon oxide film; patterning after forming a photoresist film on the silicon nitride film; and selectively etching the silicon nitride film on which the patterned photoresist film is formed using the etching composition of the present invention.

At this time, the silicon oxide film, silicon nitride film, photoresist film, etc. formed on the substrate may each be formed as a single film, a double film, or a multi-layer (multi-layer film), and in the case of a double film or a multi-layer, the stacking order is not particularly limited. does not

In addition, as the substrate, silicon, quartz, glass, a silicon wafer, a polymer, a metal, a metal oxide, etc. may be used, but the present invention is not limited thereto. As the polymer substrate, a film substrate such as polyethylene terephthalate, polycarbonate, polyimide, polyethylene naphthalate, cycloolefin polymer, etc. may be used, but limited thereto doesn't happen

The etching method according to an embodiment of the present invention may selectively etch the silicon nitride layer by etching the silicon nitride layer faster than the silicon oxide layer. In addition, it is possible to effectively prevent the silicon oxide film from being unnecessarily removed or damaged.

In the present invention, the silicon nitride film is a concept including SiN, SiON, doped SiN film, and the like, and means a film quality that is often used as an insulating film when forming a gate electrode.

In addition, the silicon oxide film in the present invention is not limited as long as it is a silicon oxide film commonly used in the art, but for example, a Spin On Dielectric (SOD) film, a High Density Plasma (HDP) film, a thermal oxide film, or a borophosphate silicate (BPSG) film. Glass) film, PSG (Phospho Silicate Glass) film, BSG (Boro Silicate Glass) film, PSZ (Polysilazane) film, FSG (Fluorinated Silicate Glass) film, LPTEOS (Low Pressure Tetra Ethyl Ortho Silicate) film, PETEOS (Plasma Enhanced Tetra) film Ethyl Ortho Silicate) Film, HTO (High Temperature Oxide) Film, MTO (Medium Temperature Oxide) Film, USG (Undoped Silicate Glass) Film, SOG (Spin On Glass) Film, APL (Advanced Planarization Layer) Film, ALD (Atomic Layer) Film Deposition) film, PE-Plasma Enhanced oxide film, O3-TEOS (O3-Tetra Ethyl Ortho Silicate) film, etc. are mentioned.

In this case, the silicon oxide film or the silicon nitride film may be formed in various thicknesses depending on the purpose. For example, the silicon oxide film or the silicon nitride film may be independently formed to have a thickness of 100 to 3,000 Å, but is not limited thereto.

In addition, the method of selectively etching the silicon nitride layer using the etching composition according to the present invention may be performed according to a method commonly used in the art, and examples include a method of immersion, a method of spraying, etc. there is. At this time, the etching method may be carried out at a process temperature of 100 ° C. or higher, preferably at 100 to 500 ° C., more preferably at a process temperature of 100 to 300 ° C. The appropriate temperature is different from other processes and other factors. Of course, it may be changed according to need in consideration.

The present invention also provides a method of manufacturing a semiconductor device including the above-described etching method.

According to the method of manufacturing a semiconductor device according to an embodiment of the present invention, when the silicon oxide film and the silicon nitride film are alternately stacked or mixed, selective etching of the silicon nitride film is possible, and by effectively suppressing damage to the silicon oxide film, the etching Minimize the damage to the silicon oxide film by

In addition, it is possible to effectively prevent the generation of residues, which has been a problem in the conventional etching process, thereby securing the stability and reliability of the process.

Therefore, in the etching method according to the present invention, the silicon nitride film can be selectively removed compared to the silicon oxide film, and the etching rate and the etching selectivity can be kept constant despite the increase in processing time, so a process requiring selective etching of the silicon nitride film can be effectively applied to

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are provided to explain the present invention in more detail, and the scope of the present invention is not limited by the following examples. Of course, the following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

In the present invention, unless otherwise stated, all temperatures are in °C, and the amount of the composition used is in units of weight %.

(Experimental Example 1) Measurement of etch rate and etching rate of silicon nitride film and silicon oxide film

In order to examine the etching performance of the etching compositions prepared in the following Examples and Comparative Examples, a silicon nitride film (SiN film) wafer and a silicon oxide film (LPTEOS film) wafer were prepared by depositing in the same manner as in the semiconductor manufacturing process using the CVD method. .

Before etching, the thickness before etching was measured using an ellipsometer (Ellipsometer, NANO VIEW, SEMG-1000), which is a thin film thickness measuring device. The etching process was performed by immersing the wafer in a silicon nitride etchant (Examples 1 to 7 and Comparative Examples 1 to 4) maintained at an etching temperature of 157° C. in a quartz bath for 10 minutes each. After the etching was completed, it was washed with ultrapure water and then the remaining etchant and moisture were completely dried using a drying device. In addition, the method was evaluated by performing 10 batches without changing the chemical solution using 1 batch.

At this time, the etching rate was calculated by dividing the difference between the thickness before etching and the thickness after etching by the etching time (minutes) using an ellipsometer (Ellipsometer, J.A WOOLLAM, M-2000U), and the results are described in Table 2 below. did

(Experimental Example 2) Evaluation of selective etching of silicon nitride film to silicon oxide film

The etching selectivity (etch rate of silicon nitride film/etch rate of silicon oxide film) was calculated based on the ratio of the etching rate of the silicon nitride film and the etching rate of the silicon oxide film, and is shown in Table 2 below.

(Experimental Example 3) Evaluation of particle generation

The surface of the silicon oxide film etched in the following Examples and Comparative Examples was measured with a scanning electron microscope (SEM) to examine whether or not particles were generated, and it is shown in Table 2 below.

(Examples 1 to 9 and Comparative Examples 1 to 5)

After mixing in the composition ratio shown in Table 1 below, the mixture was stirred at a speed of 500 rpm at room temperature for 5 minutes to prepare a silicon nitride etching composition. The content of water was set as the remaining amount such that the total weight of the composition was 100% by weight.

As shown in Table 2, the etching composition according to the present invention has excellent selectivity for the silicon nitride film compared to the silicon oxide film, and its etchability (eg, the etching rate for the silicon nitride film and It can be seen that there is almost no change in etching selectivity, etc.).

In addition, it was confirmed that, when the etching composition according to the present invention employs a nitrogen-containing etching stabilizer having an aliphatic substituent, it was confirmed that better etching ability could be realized. It was confirmed that the etch selectivity of the silicon nitride film could be remarkably improved. In addition, since the etching composition according to the present invention does not cause problems such as particles on the substrate after the etching process, it is possible to minimize the defect rate of the manufactured semiconductor device.

In addition, in the case of Comparative Examples 1 to 4, particles were generated, which was not suitable for etching the silicon nitride layer. In addition, in the case of Comparative Example 5, particle generation was not observed, but it was confirmed that the etching rate for the silicon nitride layer was remarkably low because the high-temperature process could not be performed.

In short, the etching composition according to the present invention enables selective etching of the silicon nitride film by combining a predetermined nitrogen-containing etching stabilizer with phosphoric acid, as well as maintaining the initial etching ability despite long-term use, thereby significantly improving production efficiency can be raised In addition, it is possible to provide a high-quality semiconductor device by minimizing damage to the film quality of the silicon oxide film during the etching process and at the same time effectively preventing the generation of particles.

The present invention is not limited by the above-described embodiments and the accompanying drawings, and it is common in the art to which the present invention pertains that various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It will be clear to those who have knowledge.

Claims (10)

30 to 95% by weight of phosphoric acid, 0.005 to 10% by weight of a nitrogen-containing etch stabilizer, and the balance of water, based on the total weight of the composition;
The nitrogen-containing etching stabilizer is an amine-based compound selected from alkanolamine, alkoxyamine, and polyvalent ethyleneamine; an amide compound selected from N-alkylamide, N-alkyl acetamide and alkylimide; a urea-based compound selected from urea and alkylurea; And an isocyanate-based compound selected from alkyl isocyanate; One or more selected from, an etching composition for selectively etching a silicon nitride layer compared to a silicon oxide layer. delete delete The method of claim 1,
An etching composition that satisfies the following Relations 1 and 2, wherein the reduction rate of the etching rate after the repeated etching process is performed.
[Relational Expression 1]
△ERD _SiNx ≤ 5%
[Relational Expression 2]
△ERD _SiO2 ≤ 5%
[In Relations 1 and 2,
ΔERD _SiNx is an etch rate decrease rate compared to the initial etch rate for the silicon nitride film;
ΔERD _SiO2 is the rate of decrease in the etch rate compared to the initial etch rate for the silicon oxide layer.] The method of claim 1,
An etching composition that satisfies the etching selectivity of the following Relational Equation 3.
[Relational Expression 3]
3.0 ≤ E _SiNx / E _SiO2
[In Relation 3,
E _SiNx is the etch rate for the silicon nitride film;
E _SiO2 is the etch rate for the silicon oxide film.] 6. The method of claim 5,
An etching composition having a change in the etching selectivity of 0.5 or less even after repeated etching processes. 7. The method of claim 6
An etching rate of 30 to 100 Å/min for the silicon nitride layer is an etching composition. The method of claim 1,
Etching composition further comprising a silicon-based compound. 9. The method of claim 8,
The silicon-based compound is an etching composition represented by the following formula (1).
[Formula 1]
Si(OR ¹ ) _4-n (R ² ) _n
[In Formula 1,
R ¹ and R ² are each independently selected from hydrogen and (C1-C3)alkyl;
n is an integer from 0 to 3.] The method of claim 1,
Etching composition for high temperature etching of 100 ℃ or more.