KR20180109745A - Etching composion for silicon nitride layer - Google Patents

Abstract

The present invention relates to a silicon nitride film etching composition, which can minimize the etching rate to a silicon oxide film, can selectively etch a silicon nitride film, leaves no particles on a substrate, and is stable at a high temperature.

Description

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

The present invention relates to a silicon nitride film etching composition capable of minimizing an etching rate for a silicon oxide film, selectively etching a silicon nitride film, and preventing particles from remaining on the substrate and being stable at a high temperature.

The silicon oxide film (SiO2) and the silicon nitride film (SiNx) are used as typical insulating films used in a semiconductor manufacturing process, and they may be used alone or alternatively, one or more silicon oxide films and one or more silicon nitride films may be alternately stacked. 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.

Conventionally, a wet etching process for a silicon nitride film generally uses a mixture of phosphoric acid and deionized water at a high temperature of about 160 ° C. However, in order to prevent etching of a silicon oxide film due to phosphoric acid in a high temperature etching process, silicon- One etching composition has been proposed.

However, when the nitride film is etched by using an etching composition containing phosphoric acid and silicate or silicate, silicic acid or silicate may cause particles that can affect the substrate, which is not suitable for the semiconductor manufacturing process.

In Korean Patent Laid-Open Nos. 2011-0037741 and 2011-0037766, oxime silane and alkoxysilane compound were added to phosphoric acid to control the etching rate of the silicon oxide film to 1 Å / min or less, and a fluorine compound was added thereto to etch the nitride film Respectively. However, when a conventional silane compound is contacted with water, a siloxane compound (Si-O-Si) of a polymer is formed and foreign matter adheres to the surface of the wafer. There is a problem in that the etching rate of the silicon nitride film and the oxide film A problem can not be maintained.

As described above, due to the stability problem of the silicon additive included in the conventional etching composition, particles are generated and cause many problems in the semiconductor manufacturing process.

Therefore, there is a need for a high selectivity non-etchant for a silicon nitride film that is stable in additives and capable of selectively etching a silicon nitride film without damaging the silicon oxide film.

Korea Patent Publication No. 2011-0037741 Korea Patent Publication No. 2011-0037766 Korean Patent Publication No. 2014-0079267 Korean Patent Publication No. 2017-0001801

An object of the present invention is to provide a silicon nitride film etching composition having a high selectivity which can selectively etch a silicon nitride film while minimizing etching of the silicon oxide film and does not cause problems such as generation of particles affecting semiconductor device characteristics.

The present invention relates to a process for the preparation of And a silicon-based compound represented by the following general formula (1).

[Chemical Formula 1]

In Formula 1,

R ₁₁ to R ₁₃ are each independently hydrogen, halogen, hydroxy, alkoxy of 1 to 10 carbon atoms, alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, or alkenyl of 2 to 10 carbon atoms;

이고;R ₁ to R ₃ are each independently hydrogen, halogen, hydroxy, alkoxy of 1 to 10 carbon atoms, alkyl of 1 to 10 carbon atoms, alkenyl of 2 to 10 carbon atoms, or

ego;

L ₁ , L, L ₁ 'and L' are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;

R ₂₁ to R ₂₃ each independently represent hydrogen, halogen, hydroxy, alkoxy having 1 to 10 carbon atoms, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, or alkenyl having 2 to 10 carbon atoms;

a and b are each independently an integer of 0 to 20, provided that the sum of a and b is an integer of at least 1;

c is an integer from 0 to 20;

a ', b' and c 'are each independently an integer of 0 to 20;

m and n are each independently an integer of 0 to 5,

When m is an integer of 2 or more, L may be the same or different from each other, and R ₁₃ may be the same or different from each other,

When n is an integer of 2 or more, L 'may be the same as or different from each other.

In the silicon nitride film etching composition according to an embodiment of the present invention, the silicon-based compound may be at least one selected from the silicon-based compounds represented by the following general formulas (2) to (4).

(2)

(3)

[Chemical Formula 4]

In the above Chemical Formulas 2 to 4,

R ₁₁ to R ₁₄ are each independently hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, or alkenyl having 2 to 10 carbon atoms;

이고;R ₁ to R ₃ are each independently halogen, hydroxy, alkoxy of 1 to 10 carbon atoms or

ego;

L ₁ , L ₂ and L ₃ are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;

a and b are each independently an integer of 0 to 20, provided that the sum of a and b is an integer of at least 1;

c and d are each independently an integer of 1 to 20;

L ₁ 'and L' are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;

R ₂₁ to R ₂₃ are each independently hydrogen, alkyl having 1 to 10 carbons, cycloalkyl having 3 to 8 carbons, or alkenyl having 2 to 10 carbons;

a ', b' and c 'are each independently an integer of 0 to 20;

n is an integer of 0 to 2;

In the silicon nitride film etching composition according to an embodiment of the present invention, R ₁₁ to R ₁₄ in each of the silicon-based compounds represented by Chemical Formulas 2 to 4 are each independently hydrogen or alkyl having 1 to 7 carbon atoms; R ₁ to R ₃ are each independently halogen, hydroxy or alkoxy of 1 to 7 carbon atoms; L ₁ , L ₂ and L ₃ are each independently alkylene having 1 to 7 carbon atoms or cycloalkylene having 5 to 7 carbon atoms; a and b are each independently an integer of 0 to 5, provided that the sum of a and b is an integer of at least 1; c and d may each independently be an integer of 1 to 5.

The silicon nitride film etching composition according to an embodiment of the present invention may include 60 to 95% by weight of phosphoric acid and 0.01 to 3% by weight of silicon-based compounds based on the total weight of the silicon nitride film etching composition.

In the silicon nitride film etching composition according to an embodiment of the present invention, the silicon nitride film / oxide film etching selectivity may be 200 or more.

 The silicon nitride film etching composition according to an embodiment of the present invention may further include at least one additive selected from inorganic acids, organic acids, and ammonium salts.

In the silicon nitride film etching composition according to an embodiment of the present invention, the inorganic acid may be at least one selected from the group consisting of hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, hydrogen peroxide acid, perchloric acid and boric acid. Specific examples of the organic acid include formic acid, acetic acid, diacetic acid, iminodiacetic acid, methanesulfonic acid, ethanesulfonic acid, lactic acid, ascorbic acid, oxalic acid, propionic acid, butanoic acid, valeric acid, butylacetic acid, enanthic acid, capric acid, But are not limited to, succinic acid, malic acid, maleic acid, malonic acid, glycolic acid, gluconic acid, glicaric acid, glutaric acid, adipic acid, D-gluconic acid, itaconic acid, citraconic acid, Glutamic acid, methyl succinic acid, and citric acid; Specific examples of the ammonium salt include (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₃ PO ₄ , NH ₄ NO ₃ , NH ₄ CH ₃ CO ₂ , NH ₄ HCO ₃ , NH ₄ Cl, NH ₄ F, NH ₄ HF ₂ and NH ₄ BF ₄ .

The silicon nitride film etching composition according to an embodiment of the present invention may further include at least one selected from a surfactant, a sequestering agent, an antioxidant, and a corrosion inhibitor.

The present invention also provides a method of selectively etching a silicon nitride film to a silicon oxide film using the silicon nitride film etching composition, and a method of manufacturing a semiconductor device including the etching method.

The silicon nitride film etching composition of the present invention can suppress the etching of the silicon oxide film, can etch the silicon nitride film with high selectivity, minimize the damage of the silicon oxide film, effectively prevent the generation of particles and prevent unwanted damage in the etching process It is possible to prevent the problem of deterioration of device characteristics produced.

In the silicon nitride film etching composition of the present invention, at least one repeating unit of ethylene oxide (EO) is bonded to the terminal nitrogen atom, hydrogen is bonded to the terminal oxygen atom of the repeating unit of ethylene oxide, or alkyl, The silicon oxide film is prevented from being etched by phosphoric acid heated to a high temperature due to the stability of the silicon-based compound in the etching process, and the side reaction of the silicon-based compound So that the silicon nitride film can be selectively etched without generating any particles. Therefore, the silicon nitride film etching composition according to the present invention can improve the device characteristics by selectively etching the nitride film while preventing the oxide film from damaging the oxide film, deteriorating the electrical characteristics due to etching of the oxide film, and generating particles during the nitride film etching.

In addition, the silicon nitride film etching composition of the present invention is excellent in storage stability and can maintain a stable etching rate and a high etching selectivity for a silicon nitride film even after a repeated etching process.

Hereinafter, the present invention will be described in more detail. Unless otherwise defined, technical terms and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the following description, And a description of the known function and configuration will be omitted.

In this specification, the term "etching selectivity ratio (E _SiNx / E _SiO2 )" 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. Further, when the etching rate of the silicon oxide film is close to zero or when the etching selectivity ratio is large, it means that the silicon nitride film can be selectively etched.

The term " change in etch selectivity ratio " in this specification refers to the absolute value of the difference between the initial etch selectivity versus etch selectivity ratios when the etch process is repeated two or more times using the same etch composition.

The term " Etch rate drift (DELTA ERD) " in the present specification 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 as DELTA ERD (%) = [1 - {(etching rate in use more than n times) / (etching rate in use once)}] to be. In general, the etching rate is defined as the decreasing rate as the etching rate, that is, the etching rate, tends to decrease as the etching process is repeatedly performed, and the rate of change is interpreted in the same sense.

The term " halogen " as used herein means a fluorine, chlorine, bromine or iodine atom.

As used herein, the term " alkyl " refers to a straight or branched saturated hydrocarbon monovalent group consisting solely of carbon and hydrogen atoms, specifically methyl, ethyl, propyl, isopropyl, butyl, isobutyl, Octyl, nonyl, and the like.

The term " alkoxy " as used herein means a monovalent group in which oxygen and alkyl are bonded, wherein 'alkyl' is as defined above. Examples of such alkoxy include, but are not limited to, methoxy, ethoxy, isopropoxy, butoxy, isobutoxy, t-butoxy and the like.

As used herein, the term " alkenyl " refers to a straight or branched unsaturated hydrocarbon monovalent group comprising at least one double bond between two or more carbon atoms, and specifically includes ethenyl, propenyl, prop- 2-butenyl, 2-butenyl, 2-butenyl, 2-pentenyl, -Dimethyl-2-butenyl, and the like.

The term " cycloalkyl " as used herein refers to a saturated carbocyclic monovalent group consisting of one or more rings, including but not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like Do not.

The term " alkylene " as used herein means a straight or branched saturated hydrocarbon divalent group consisting of only carbon and hydrogen atoms, specifically methylene, ethylene, propylene, isopropylene, butylene, isobutylene, Pentylene, hexylene, octylene, nonylene, and the like.

The term " cycloalkylene " as used herein refers to a saturated carbocyclic divalent group consisting of one or more rings and specifically includes cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene and the like , But is not limited thereto.

The present invention relates to a process for the preparation of And a silicon-based compound represented by the following formula (1), wherein the silicon-based compound is a component capable of inhibiting etching of silicon oxide.

[Chemical Formula 1]

In Formula 1,

R ₁₁ to R ₁₃ are each independently hydrogen, halogen, hydroxy, alkoxy of 1 to 10 carbon atoms, alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, or alkenyl of 2 to 10 carbon atoms;

이고;R ₁ to R ₃ are each independently hydrogen, halogen, hydroxy, alkoxy of 1 to 10 carbon atoms, alkyl of 1 to 10 carbon atoms, alkenyl of 2 to 10 carbon atoms, or

ego;

L ₁ , L, L ₁ 'and L' are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;

R ₂₁ to R ₂₃ are each independently hydrogen, halogen, hydroxy, alkoxy having 1 to 10 carbon atoms, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, or alkenyl having 2 to 10 carbon atoms;

a and b are each independently an integer of 0 to 20, provided that the sum of a and b is an integer of at least 1;

c is an integer from 0 to 20;

a ', b' and c 'are each independently an integer of 0 to 20;

m and n are each independently an integer of 0 to 5,

When m is an integer of 2 or more, L may be the same or different from each other, and R ₁₃ may be the same or different from each other,

When n is an integer of 2 or more, L 'may be the same as or different from each other.

The silicon-based compound of formula (1) has a structure in which at least one ethylene oxide repeating unit is bonded to a terminal nitrogen atom and a structure in which a terminal oxygen atom of the ethylene oxide repeating unit is bonded with hydrogen or a hydrocarbon group such as alkyl, cycloalkyl or alkenyl is bonded Lt; / RTI > The silicon-based compound of Chemical Formula 1 has a high solubility in water due to the increase of hydrogen bonding with water due to the repeating unit of ethylene oxide bonded to the nitrogen atom in the molecule, and the hydrocarbon which is bonded to the terminal oxygen atom of the ethylene oxide repeating unit The side reaction of the silicon-based compound is prevented during the high-temperature etching process. Due to the stability of such a silicon-based compound, the phosphoric acid heated at a high temperature during the etching process can be prevented from etching the silicon oxide film, and the generation of side reactions can be prevented to prevent the generation of particles, so that the silicon nitride film can be selectively etched do.

The silicon-based compound according to an embodiment of the present invention may preferably be at least one selected from the silicon-based compounds represented by the general formulas (2) to (4) in view of preventing the silicon oxide film from being etched.

(2)

(3)

[Chemical Formula 4]

In the above Chemical Formulas 2 to 4,

R ₁₁ to R ₁₄ are each independently hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, or alkenyl having 2 to 10 carbon atoms;

이고;R ₁ to R ₃ are each independently halogen, hydroxy, alkoxy of 1 to 10 carbon atoms or

ego;

L ₁ , L ₂ and L ₃ are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;

a and b are each independently an integer of 0 to 20, provided that the sum of a and b is an integer of at least 1;

c and d are each independently an integer of 1 to 20;

L ₁ 'and L' are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;

R ₂₁ to R ₂₃ are each independently hydrogen, alkyl having 1 to 10 carbons, cycloalkyl having 3 to 8 carbons, or alkenyl having 2 to 10 carbons;

a ', b' and c 'are each independently an integer of 0 to 20;

n is an integer of 0 to 2;

The silicon-based compound according to an embodiment of the present invention is more preferably each of R ₁₁ to R ₁₄ in the general formulas 2 to 4 is independently hydrogen or alkyl having 1 to 7 carbon atoms; R ₁ to R ₃ are each independently halogen, hydroxy or alkoxy of 1 to 7 carbon atoms; L ₁ , L ₂ and L ₃ are each independently alkylene having 1 to 7 carbon atoms or cycloalkylene having 5 to 7 carbon atoms; a and b are each independently an integer of 0 to 5, provided that the sum of a and b is an integer of at least 1; c and d are each independently at least one selected from silicon-based compounds having an integer of 1 to 5.

In the silicon-based compound according to one embodiment of the present invention, R ₁₁ to R ₁₄ in the general formulas 2 to 4 are each independently hydrogen or alkyl having 1 to 4 carbon atoms; R ₁ to R ₃ are each independently halogen, hydroxy or alkoxy of 1 to 4 carbon atoms; L ₁ , L ₂ and L ₃ are each independently alkylene having 2 to 5 carbon atoms or cycloalkylene having 5 to 6 carbon atoms; a and b are each independently an integer of 0 to 5, provided that the sum of a and b is an integer of at least 1; c and d are each independently at least one selected from silicon-based compounds having an integer of 1 to 5.

The silicon-based compound according to an embodiment of the present invention is even more preferably each of R ₁₁ to R ₁₄ is independently hydrogen, methyl, ethyl, propyl or butyl; R ₁ to R ₃ are each independently chloro, hydroxy, methoxy, ethoxy or butoxy; L ₁ , L ₂ and L ₃ are each independently ethylene, propylene, butylene, pentylene, hexylene, cyclopentylene or cyclohexylene; a and b are each independently an integer of 0 to 5, provided that the sum of a and b is an integer of at least 1; c and d are each independently at least one selected from silicon-based compounds having an integer of 1 to 5.

The silicon-based compound according to one embodiment of the present invention may be at least one silicon-based compound selected from the following structures, but is not limited thereto.

The phosphoric acid included in the silicon nitride film etching composition according to an embodiment of the present invention provides hydrogen ions in the composition and is capable of maintaining high-temperature process conditions to etch the silicon nitride film.

The silicon nitride film etching composition of the present invention may contain a remaining amount of water. The water is not particularly limited, and it is preferably deionized water, more preferably, deionized water for semiconductor processing has a resistivity value of 18 M? It is good.

The content of phosphoric acid, silicon compound and water constituting the silicon nitride film etching composition according to an embodiment of the present invention is not particularly limited, but is preferably 60 to 95% by weight of phosphoric acid, 0.01 to 100% by weight of silicon compound To 3% by weight and a balance of water. Within this range, it is possible to realize a high silicon oxide / nitride selective ratio and an improved silicon nitride etch rate while maintaining high temperature stability in a semiconductor etching process, and effectively inhibit the formation of particles.

When the content of the phosphoric acid in the etching composition of the present invention is less than 60 wt%, the etching rate of the silicon nitride film may be lowered and the nitride film may not be easily removed. If the content of the phosphoric acid exceeds 95 wt% The silicon nitride film / oxide film selection ratio can be reduced by increasing the speed.

More preferably, the silicon nitride film etching composition according to an embodiment of the present invention may include 70 to 90% by weight of phosphoric acid, 0.05 to 1% by weight of silicon-based compounds, and a residual amount of water based on the total weight of the silicon nitride film etching composition. In such a range, the stability in a high-temperature etching process is maintained and the etching rate of the silicon oxide film is effectively reduced to effectively improve the silicon nitride film / oxide film selection ratio and to prevent the generation of particles. In addition, the etching rate for the silicon oxide film and the silicon nitride film can be maintained constant despite the repetitive etching process.

Particularly preferably, the silicon nitride film etching composition according to an embodiment of the present invention may contain 75 to 85% by weight of phosphoric acid, 0.05 to 0.5% by weight of silicon compound, and water in a residual amount based on the total weight of the silicon nitride film etching composition. In such a range, the stability in the etching process at a high temperature of 140 ° C or more is maintained, the generation of particles is completely suppressed and the etching rate of the silicon oxide film is remarkably reduced to realize a very high silicon nitride / oxide selective ratio, It is possible to maintain a stable etch rate and high etch selectivity to the silicon nitride film even after the process.

In addition, the silicon nitride film etching composition according to an embodiment of the present invention may further include at least one additive selected from inorganic acids, organic acids, and ammonium salts, if necessary, for controlling the pH. . The content of the additive is not particularly limited, but may be 0.01 to 10% by weight based on the total weight of the silicon nitride film etching composition.

As a specific example, the inorganic acid may be at least one selected from the group consisting of hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, hydrogen peroxide acid, perchloric acid and boric acid; The organic acid may be selected from the group consisting of formic acid, acetic acid, diacetic acid, iminodiacetic acid, methanesulfonic acid, ethanesulfonic acid, lactic acid, ascorbic acid, oxalic acid, propionic acid, butanoic acid, valeric acid, butyl acetic acid, enanthic acid, capric acid, Maleic acid, malonic acid, glycolic acid, gluconic acid, glycolic acid, glutaric acid, adipic acid, D-gluconic acid, itaconic acid, citraconic acid, mesaconic acid, 2- oxoglutaric acid, trimellitic acid, Glutaric acid, glutaric acid, glutaric acid, glutaric acid, glutaric acid, glutaric acid, glutaric acid, glutaric acid, glutaric acid, Wherein the ammonium salt is selected from the group consisting of (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₃ PO ₄ , NH ₄ NO ₃ , NH ₄ CH ₃ CO ₂ , NH ₄ HCO ₃ , NH ₄ Cl, NH ₄ F, NH ₄ HF _{2, 4} BF < ₄ >.

In addition, the silicon nitride film etching composition according to an embodiment of the present invention may further include optional additives conventionally used in the art to improve the etching performance. Examples of the optional additives include surfactants, antioxidants, A corrosion inhibitor or the like may be used.

The surfactant is used to remove the etched residue. Any surfactant that can be dissolved in the silicon nitride film etching composition of the present invention can be used without limitation. For example, an anionic surfactant, a cationic surfactant, or a nonionic surfactant Can be used. Examples of the cationic surfactant include amines such as C ₈ H ₁₇ NH _2. Examples of the anionic surfactant include hydrocarbon-based carboxylic acids such as C ₈ H ₁₇ COOH, hydrocarbon-based ones such as C ₈ H ₁₇ SO ₃ H Sulfonic acid, and H (CF ₂ ) ₆ COOH. Nonionic surfactants include ethers such as polyoxyalkylene alkyl ethers. The surfactant may further comprise 0.0005 to 5% by weight based on the total weight of the silicon nitride film etching composition.

The antioxidant and the corrosion inhibitor are used to prevent corrosion of a metal or a metal compound used as a semiconductor device material in an etching process. The antioxidant and the corrosion inhibitor can be used without limitation as long as they are used in the industry. For example, An azole compound, an amine compound, an acid compound, and a polyhydric alcohol compound may be used.

Examples of the azole compounds include 5-aminotetrazole, 5-methyl-1H-tetrazole, 1H-tetrazole-5-acetic acid, imidazole, 2-methylimidazole, 1- , Histidine, 4-methylimidazole, 1,2,3-triazole, 1,2,4-triazole, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidone, pyrroline, benzotriazole, benzo 5-methyl-1H-benzotriazole, indole, purine, 2-aminobenzimidazole, adenine, guanine, tolutorazole, 4-methyl-1H-benzotriazole, 1H -Benzotriazole-1-methanol, and the like. Examples of the amine compound include p-phenylenediamine, polyaniline, aniline, N-phenyl-p-phenylenediamine, Hydroxyethyl) piperazine, 2-methylpiperazine, triethylamine, 2-dimethylaminoethanol and the like. Examples of the acid compounds include glycine, nicotinic acid, sodium gluconate, valine, glutamic acid, aspartic acid, ascorbic acid, nitrobenzene, and picric acid. As the polyhydric alcohol compound, D-sorbitol and the like can be mentioned. The antioxidant and the corrosion inhibitor may further include 0.01 to 10% by weight based on the total weight of the silicon nitride film etching composition.

When etching is performed on a semiconductor wafer using the silicon nitride film etching composition according to an embodiment of the present invention, the etching rate of the silicon nitride film of the silicon nitride film etching composition is 50 to 80 Å / min, and the etching rate of the silicon oxide film is 0 to 0.4 A / min, and the silicon nitride film / oxide film etch selectivity (E _SiNx / E _SiO2 ) may be 200 or more, preferably ∞. In particular, when the etching rate of the silicon oxide film is close to zero and the silicon nitride film is selectively etched, the silicon nitride film / oxide film selection ratio may be infinite.

When the silicon nitride film and the silicon oxide film are mixed, the silicon nitride film etching method of the present invention selectively etches the silicon nitride film without causing an etching effect on the silicon oxide film, so that the silicon nitride film / Can be implemented.

In addition, the silicon nitride film etching composition of the present invention realizes high-temperature stability due to the silicon-based compound, inhibits etching of the silicon oxide film by phosphoric acid heated at a high temperature, thereby preventing side reaction, The etching rate of the silicon nitride film can be maintained, and excellent semiconductor device characteristics can be realized.

The silicon nitride film etching composition of the present invention can effectively etch the silicon nitride film with excellent stability even during the high temperature semiconductor etching process as well as effectively suppress the generation of particles and can provide stable etching rate and etching selectivity to the silicon nitride film even after the repeated etching process Can be given.

The present invention provides a method of selectively etching a silicon nitride film to a silicon oxide film using the etching composition. At this time, the etching may be performed according to a method commonly used in the art.

According to the method of etching according to an embodiment of the present invention, the silicon nitride film can be etched faster than the silicon oxide film, the silicon nitride film can be selectively etched, particles are not formed during the etching process, The nitride film can be etched. In addition, it is possible to effectively prevent the silicon oxide film from being unnecessarily removed or damaged.

In the present invention, the term silicon nitride film refers to a film quality which is widely used as an insulating film when forming a gate electrode or the like, including SiN, SiON, doped SiN film and the like.

The silicon oxide film is not limited as long as it is a silicon oxide film commonly used in the art. For example, a silicon oxide film may be formed using a spin on dielectric (SOD) film, a high density plasma (HDP) film, a thermal oxide, a borophosphate silicate glass ), A PSG (Phospho Silicate Glass) film, a BSG (Borosilicate Glass) film, a PSZ (Polysilazane) film, a FSG (Fluorinated Silicate Glass) film, a LPTEOS (Low Pressure Tetra Ethyl Ortho Silicate) (APD) film, an ALD (Atomic Layer Deposition) film, an AlGaN layer, an AlGaN layer, an AlGaN layer, ) Film, a PE-oxide film (Plasma Enhanced oxide), an O3-TEOS (O3-Tetra Ethyl Ortho Silicate) film, and a combination thereof.

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

Further, the step of selectively etching the nitride film using the silicon nitride film etching composition of the present invention can be performed according to a well-known method in the art, and examples thereof include a method of soaking and a method of spraying. The process temperature in the etching process may be in the range of 100 ° C or higher, preferably 100 to 500 ° C, more preferably 100 to 300 ° C, and the appropriate temperature may be changed as necessary in consideration of other processes and other factors .

The present invention also relates to the above phosphoric acid; And at least one of the silicon-based compounds represented by the formula (1). The present invention also provides a method of manufacturing a semiconductor device including the step of etching using the silicon nitride film etching composition.

The kind of the semiconductor element is not particularly limited in the present invention.

The etching process is characterized in that the silicon nitride film is selectively etched with respect to the silicon oxide film without causing a particle problem.

According to the method for fabricating a semiconductor device according to an embodiment of the present invention, when the silicon nitride film and the silicon oxide film are alternately stacked or mixed, the silicon nitride film can be selectively etched and the damage of the silicon oxide film is effectively suppressed, Thereby minimizing the damage of the silicon oxide film by the silicon oxide film. In addition, it is possible to completely prevent the generation of particles, which have been a problem in the conventional etching process, and to secure the stability and reliability of the process.

Therefore, the etching method according to the present invention is capable of selectively removing the silicon nitride film compared to the silicon oxide film, effectively preventing the generation of particles, and maintaining the etch rate and etch selectivity constant despite several repetitions of the etching process The generation of particles can be completely prevented and the method can be efficiently applied to various processes requiring selective etching of the silicon nitride film with respect to the silicon oxide film.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[Production Example 1] Silicon-based compound Si-1 [R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = 1,3-propylene, a = 1, b = 0, R ₁₁ = R ₁₂ = Manufacture of hydrogen]

(100 parts by weight) was added to a flask equipped with a thermometer, a cooling tube and a stirrer, and 2- (allylamino) ethanol was added in a molar ratio of 1: 1 with triethoxysilane , And ethyl acetate (500 parts by weight) was added as a solvent. The reaction mixture was heated to 50 占 폚 and then Karstedt's catalyst (0.004 parts by weight) was added thereto and hydrogen silylation was carried out at 80 占 폚 for 3 hours to obtain a compound Si-1.

^{1 H-NMR (500 MHz,} CDCl 3): δ 0.67 (t, 2H), 1.26 (t, 9H), 1.57 (m, 2H), 2.2 (Br, 2H), 2.55 (m, 2H), 2.74 ( m, 2H), 3.68 (m, 2H), 3.84 (m, 6H)

[Production Examples 2 to 9] Preparation of silicon-containing compounds Si-2 to Si-9

Silicon-based compounds Si-2 to Si-9 were prepared in the same manner as in Preparation Example 1. The structures of the silicon-based compounds Si-2 to Si-9 were as follows.

Silicon compound Si-2: in _{(EtO) 3 Si-CH 2} CH 2 CH 2 -N [CH 2 CH 2 OH] 2 [R 1 = R 2 = R 3 = ethoxy in formula (2), L ₁ = _1, Propylene, a = b = 1, R ₁₁ = R ₁₂ = corresponding to hydrogen]

Si-3: (HO) ₃ Si-CH ₂ CH ₂ CH ₂ -N [CH ₂ CH ₂ OH] _{2 wherein} R ₁ = R ₂ = R ₃ = hydroxy, L ₁ = Propylene, a = b = 1, R ₁₁ = R ₁₂ = corresponding to hydrogen]

Silicon compound _{Si-4: (Cl) 3} Si-CH 2 CH 2 CH 2 -N [CH 2 CH 2 OH] 2 [R 1 = R 2 = R 3 = chloro, L ₁ = 1,3 In the formula 2 - propylene, a = b = 1, R ₁₁ = R ₁₂ = corresponding to hydrogen]

Silicon compound _{Si-5: (EtO) 3} Si-CH 2 CH 2 CH 2 -N (CH 2 CH 2 OH) -CH 2 CH 2 CH 2 -N [CH 2 CH 2 OH] 2 [R in the formula (3) ₁ = R ₂ = R ₃ = ethoxy, L ₁ = L ₂ = 1,3-propylene, a = b = c = 1, R ₁₁ = R ₁₂ = R ₁₃ =

Silicon compound _{Si-6: (EtO) 3} Si-CH 2 CH 2 CH 2 -N (CH 2 CH 2 OH) -CH 2 CH 2 CH 2 -N (CH 2 CH 2 OH) -CH 2 CH 2 CH _{2 -} [CH ₂ CH ₂ OH] _{2 wherein} R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = L ₂ = L ₃ = 1,3-propylene, a = b = c = d = 1, R ₁₁ = R ₁₂ = R ₁₃ = R ₁₄ = corresponding to hydrogen]

Si-7: (EtO) ₃ Si-CH ₂ CH ₂ -NHCH ₂ CH ₂ OCH ₃ [wherein R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = = 1, b = 0, R ₁₁ = methyl, R ₁₂ = corresponding to hydrogen]

Silicon compound _{Si-8: (EtO) 3} Si-CH 2 CH 2 CH 2 -N ((CH 2 CH 2 O) 5 H) -CH 2 CH 2 CH 2 -N [(CH 2 CH 2 O) 5 H] ₂ [in the formula (3) in _{R 1 = R 2 = R 3} = ethoxy, L ₁ = L ₂ = 1,3- propylene, a = b = c = 5 , R 11 = R 12 = R 13 = hydrogen Applicable]

Silicon compound Si-9: the _{(EtO) 3 Si-CH 2} CH 2 CH 2 -N [(CH 2 CH 2 O) 5 CH 3] 2 [R 1 = R 2 = R 3 = ethoxy in formula (2), L ₁ = 1,3-propylene, a = b = 5, R ₁₁ = R ₁₂ = corresponding to methyl]

[Examples 1 to 10 and Comparative Examples 1 to 6] Preparation of silicon nitride film etching composition

And the mixture was 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.

division Phosphoric acid (wt%) Silicon-based compound Other ingredients water
(wt%) ingredient Content (wt%) ingredient Content (wt%) Example 1 85 Si-1 0.5 - - Balance Example 2 85 Si-1 0.1 - - Balance Example 3 85 Si-2 0.5 - - Balance Example 4 85 Si-3 0.5 - - Balance Example 5 85 Si-4 0.5 - - Balance Example 6 85 Si-5 0.5 - - Balance Example 7 85 Si-6 0.5 - - Balance Example 8 85 Si-7 0.5 - - Balance Example 9 85 Si-8 0.5 - - Balance Example 10 85 Si-9 0.5 - - Balance Comparative Example 1 85 - - - - Balance Comparative Example 2 85 - - HF 0.05 Balance Comparative Example 3 85 - - AC One Balance Comparative Example 4 85 APTES 0.5 - - Balance Comparative Example 5 85 HPST 0.5 - - Balance Comparative Example 6 85 THSPS 0.1 - - Balance Si-1: Silicon-based compound wherein R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = 1,3-propylene, a = 1, b = 0 and R ₁₁ = R ₁₂ =
Si-2: Silicon-based compound in which R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = 1,3-propylene, a = b = 1 and R ₁₁ = R ₁₂ =
Si-3: Silicon-based compound wherein R ₁ = R ₂ = R ₃ = hydroxy, L ₁ = 1,3-propylene, a = b = 1 and R ₁₁ = R ₁₂ =
Si-4: Silicon-based compound wherein R ₁ = R ₂ = R ₃ = chloro, L ₁ = 1,3-propylene, a = b = 1 and R ₁₁ = R ₁₂ =
R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = L ₂ = 1,3-propylene, a = b = c = 1, R ₁₁ = R ₁₂ = R ₁₃ = hydrogen Phosphorus-based compound
Si-6 wherein R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = L ₂ = L ₃ = 1,3-propylene, a = b = c = d = 1, R ₁₁ = R ₁₂ = R < ₁₃ > = R < ₁₄ > = hydrogen
_{Si-7: R 1 = R} 2 = R 3 = ethoxy, L ₁ = 1,2- ethylene, a = 1, b = 0 , R 11 = methyl, R ₁₂ = hydrogen compounds of silicon in the formula (2)
Si-8 wherein R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = L ₂ = 1,3-propylene, a = b = c = 5, R ₁₁ = R ₁₂ = R ₁₃ = hydrogen Phosphorus-based compound
Si-9: Silicon-based compounds in which R ₁ = R ₂ = R ₃ = ethoxy, L ₁ = 1,3-propylene, a = b = 5 and R ₁₁ = R ₁₂ =
HF: Hydrofluoric acid
AC: NH ₄ Cl (Ammonium chloride)
APTES: 3-Aminopropyl triethoxysilane (3-aminopropyltriethoxysilane)
HPST: (3-hydroxypropyl) silane triol (3-hydroxypropyl)
THSPS: 3- (trihydroxysilyl) propane-1-sulfonic acid (3- (trihydroxysilyl) propane-1-sulfonic acid)

[Experimental Example 1] Measurement of etch rate and etch rate of silicon nitride film and silicon oxide film

In order to investigate the etching performance of the silicon nitride film etching compositions prepared in Examples and Comparative Examples, a silicon nitride film (SiN film) wafer and a silicon oxide film (a thermal oxide film ) Or LP-TEOS (Low Pressure Tetra Ethyl Ortho Silicate) film) wafers were prepared.

Before the etching was started, the thickness before etching was measured using an Ellipsometer (Ellipsometer, J.A WOOLLAM, M-2000U). The wafers were immersed for 10 minutes each in a silicon nitride film etching solution (Examples 1 to 10 and Comparative Examples 1 to 6) maintained at an etching temperature of 157 占 폚 in a quartz bath, and the etching process was carried out. 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.

The etch rates were calculated by dividing the difference between the thickness before etch and the thickness after etch using an ellipsometer (Ellipsometer, JA WOOLLAM, M-2000U) divided by the etch time (minutes).

[Experimental Example 2] Evaluation of selective etching of silicon nitride film to silicon oxide film

The etch selectivity ratio (etch rate of silicon nitride film / etch rate of silicon oxide film) was calculated by the ratio of etch rate of silicon nitride film to etch rate of silicon oxide film.

[Experimental Example 3] Evaluation of particle generation degree

The surfaces of the silicon oxide films etched in Examples 1 to 10 and Comparative Examples 1 to 6 were measured with a scanning electron microscope (SEM) to check whether or not the particles were generated.

Etching process
Temperature
(° C) Nitride film
Etching rate
(Å / min) Oxide etch rate
(Å / min) Selection ratio particle
Occur
Whether ThOx ^* LP-TEOS ^** Nitride film
/ ThOx Nitride film
/ LP-TEOS Example 1 157 60.2 0 0.25 ∞ 240.8 X Example 2 157 60.9 0 0.24 ∞ 253.8 X Example 3 157 60.7 0 0.23 ∞ 263.9 X Example 4 157 60.3 0 0.24 ∞ 251.3 X Example 5 157 61.3 0.11 0.27 557.3 227.0 X Example 6 157 57.1 0 0.22 ∞ 259.5 X Example 7 157 56.5 0 0.21 ∞ 269.0 X Example 8 157 61.3 0.05 0.24 1226 255.4 X Example 9 157 59.1 0 0.22 ∞ 268.6 X Example 10 157 61.5 0 0.21 ∞ 292.9 X Comparative Example 1 157 63.2 1.6 13.4 39.5 4.7 O Comparative Example 2 157 77.4 6.0 33.8 12.9 2.3 O Comparative Example 3 157 66.3 1.5 13.6 44.2 4.9 X Comparative Example 4 157 58.1 0 0.22 ∞ 264.1 O Comparative Example 5 157 54.2 0.21 - 258.1 - O Comparative Example 6 157 52.3 0.2 - 261.5 - O ^* ThOx: thermal oxide
^** LP-TEOS: Low Pressure Tetra Ethyl Ortho Silicate Membrane

As shown in Table 2, the silicon nitride film etching compositions of Examples 1 to 10 exhibited an excellent etching rate for the silicon nitride film, and exhibited a low etching rate regardless of the kind of the silicon oxide film, resulting in an excellent etching selectivity ratio And effectively prevented particle generation.

However, the silicon nitride film etching compositions of Comparative Examples 1 and 2 were remarkably inferior in the silicon oxide film etching suppression ability, resulting in a low etching selectivity ratio, and were not suitable for selective and stable etching of the silicon nitride film due to the generation of particles. In addition, the etching composition of the silicon nitride film of Comparative Example 3 did not generate particles during the etching process, but the etching selectivity to the silicon nitride film was so low that it was not suitable for selectively etching the silicon nitride film. In addition, the silicon nitride film etching compositions of Comparative Examples 4 to 6 exhibited a high etch selectivity, but particles were generated due to side reactions during the etching process, which was unsuitable for stably etching the silicon nitride film.

That is, the etching rates of the silicon oxide films of Examples 1 to 10 were significantly lower than those of the silicon nitride film etching compositions of Comparative Examples 1 to 3 which did not contain silicon-based compounds. Therefore, when the silicon-based compound of Chemical Formula 1 is included in the silicon nitride film etching composition, the etching selectivity of the silicon nitride film to the silicon oxide film is remarkably increased by significantly suppressing the etching of the silicon oxide film.

Further, in the silicon nitride film etching compositions of Examples 1 to 10, at least one ethylene oxide repeat unit is bonded to the terminal nitrogen atom, hydrogen is bonded to the terminal oxygen atom of the ethylene oxide repeat unit, or a hydrocarbon group such as alkyl is bonded The present invention effectively inhibited the generation of particles generated during the etching process, as compared with Comparative Examples 4 to 6 including APTES, HPST and THSPS.

That is, since the silicon-based compound of Formula 1 contained in the silicon nitride film etching composition of the present invention is very stable at a high-temperature acid condition, etching of the silicon oxide film heated to a high temperature by the high temperature is effectively suppressed It is possible to prevent generation of side reactions and completely prevent occurrence of particles which have been a problem in the prior art, so that the silicon nitride film can be selectively etched without defects in the substrate, and the stability and reliability of the process can be ensured.

Therefore, the silicon nitride film etching composition according to the present invention can improve the device characteristics by selectively etching the nitride film while preventing the oxide film from damaging the oxide film, deteriorating the electrical characteristics due to etching of the oxide film, and generating particles during the nitride film etching.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments or constructions. Various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention. It will be clear to those who have knowledge.

Claims (10)

Phosphoric acid; And
A silicon-based compound represented by the following formula (1); Wherein the silicon nitride film etch composition comprises:
[Chemical Formula 1]

In Formula 1,
R ₁₁ to R ₁₃ are each independently hydrogen, halogen, hydroxy, alkoxy of 1 to 10 carbon atoms, alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, or alkenyl of 2 to 10 carbon atoms;
R ₁ to R ₃ are each independently hydrogen, halogen, hydroxy, alkoxy of 1 to 10 carbon atoms, alkyl of 1 to 10 carbon atoms, alkenyl of 2 to 10 carbon atoms, or

ego;
L ₁ , L, L ₁ 'and L' are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;
R ₂₁ to R ₂₃ each independently represent hydrogen, halogen, hydroxy, alkoxy having 1 to 10 carbon atoms, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, or alkenyl having 2 to 10 carbon atoms;
a and b are each independently an integer of 0 to 20, provided that the sum of a and b is an integer of at least 1;
c is an integer from 0 to 20;
a ', b' and c 'are each independently an integer of 0 to 20;
m and n are each independently an integer of 0 to 5,
When m is an integer of 2 or more, L may be the same or different from each other, and R ₁₃ may be the same or different from each other,
When n is an integer of 2 or more, L 'may be the same as or different from each other. The method according to claim 1,
Wherein the silicon-based compound is at least one selected from silicon-based compounds represented by the following Chemical Formulas 2, 3, and 4.
(2)

(3)

[Chemical Formula 4]

In the above Chemical Formulas 2 to 4,
R ₁₁ to R ₁₄ are each independently hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, or alkenyl having 2 to 10 carbon atoms;
R ₁ to R ₃ are each independently halogen, hydroxy, alkoxy of 1 to 10 carbon atoms or

ego;
L ₁ , L ₂ and L ₃ are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;
a and b are each independently an integer of 0 to 20, provided that the sum of a and b is an integer of at least 1;
c and d are each independently an integer of 1 to 20;
L ₁ 'and L' are each independently alkylene having 1 to 10 carbon atoms or cycloalkylene having 3 to 8 carbon atoms;
R ₂₁ to R ₂₃ are each independently hydrogen, alkyl having 1 to 10 carbons, cycloalkyl having 3 to 8 carbons, or alkenyl having 2 to 10 carbons;
a ', b' and c 'are each independently an integer of 0 to 20;
n is an integer of 0 to 2; 3. The method of claim 2,
Each of R ₁₁ to R ₁₄ is independently hydrogen or alkyl having 1 to 7 carbon atoms; R ₁ to R ₃ are each independently halogen, hydroxy or alkoxy of 1 to 7 carbon atoms; L ₁ , L ₂ and L ₃ are each independently alkylene having 1 to 7 carbon atoms or cycloalkylene having 5 to 7 carbon atoms; a and b are each independently an integer of 0 to 5, provided that the sum of a and b is an integer of at least 1; and c and d are each independently an integer of from 1 to 5. The method according to claim 1,
Wherein the silicon nitride film etching composition comprises 60 to 95% by weight of phosphoric acid and 0.01 to 3% by weight of silicon-based compound based on the total weight of the silicon nitride film etching composition. The method according to claim 1,
Wherein the silicon nitride film / oxide film etch selectivity of the silicon nitride film etch composition is 200 or more. The method according to claim 1,
Wherein the silicon nitride film etching composition further comprises at least one additive selected from inorganic acids, organic acids, and ammonium salts. The method according to claim 6,
The inorganic acid is at least one selected from the group consisting of hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, hydrogen peroxide acid, perchloric acid and boric acid; The organic acid may be selected from the group consisting of formic acid, acetic acid, diacetic acid, iminodiacetic acid, methanesulfonic acid, ethanesulfonic acid, lactic acid, ascorbic acid, oxalic acid, propionic acid, butanoic acid, valeric acid, butyl acetic acid, enanthic acid, capric acid, Maleic acid, malonic acid, glycolic acid, gluconic acid, glycolic acid, glutaric acid, adipic acid, D-gluconic acid, itaconic acid, citraconic acid, mesaconic acid, 2- oxoglutaric acid, trimellitic acid, At least one selected from the group consisting of endothelia, glutamic acid, methylsuccinic acid and citric acid; Wherein the ammonium salt is selected from the group consisting of (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₃ PO ₄ , NH ₄ NO ₃ , NH ₄ CH ₃ CO ₂ , NH ₄ HCO ₃ , NH ₄ Cl, NH ₄ F, NH ₄ HF _{2, 4} BF < _{4 &} gt ;. The method according to claim 1,
Wherein the silicon nitride film etching composition further comprises at least one selected from a surfactant, an antioxidant, and a corrosion inhibitor. A method for selectively etching a silicon nitride film as compared to a silicon oxide film using the silicon nitride film etching composition according to any one of claims 1 to 8. A method for manufacturing a semiconductor device comprising an etching process performed using the silicon nitride film etching composition according to any one of claims 1 to 8.