Silicon etching solution composition and pattern formation method using the same

Abstract

To provide a silicon etching liquid composition that improves etching speed and etching selectivity.SOLUTION: The silicon etching liquid composition and a pattern formation method using the same are provided. The silicon etching liquid composition includes a quaternary alkyl ammonium hydroxide, an amine compound, and two or more nonionic surfactants having different hydrophilic group lengths. This enables the provision of the silicon etching liquid composition with improved etching speed and etching selectivity.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a silicon etching solution composition and a pattern formation method using the same, and more particularly to a silicon etching solution composition containing an etching agent and a solvent, and a pattern formation method using the same. [Background technology]

[0002] For example, in recent years, developments have been ongoing in semiconductor devices such as DRAM, NAND FLASH memory, and logic devices to achieve large capacity while rapidly reducing critical dimensions (CD).

[0003] In semiconductor devices, silicon-based films or patterns, such as polysilicon, are widely used as materials for gate electrodes, capacitor electrodes, conductive contacts, wiring, etc. When gate electrodes or wiring are formed by direct etching of metal films, it is difficult to form patterns with desired fine dimensions due to limitations in etching resolution. Therefore, processes using polysilicon films are being researched.

[0004] In order to perform a highly reliable semiconductor device process, a high etching rate and etching uniformity are required for the target to be removed. However, in an etching process, an increase in the etching rate for the target to be removed may accelerate etching of a protective film material.

[0005] Therefore, in the etching process of a silicon film, there is a need to develop an etching solution composition that improves the etching selectivity while maintaining the etching rate and etching uniformity required to form a fine-dimensional pattern. Summary of the Invention [Problem to be solved by the invention]

[0006] One object of the present invention is to provide a silicon etchant composition having improved etching efficiency and reliability.

[0007] An object of the present invention is to provide a pattern formation method using the silicon etching liquid composition. [Means for solving the problem]

[0008] 1. A silicon etching solution composition comprising a quaternary alkylammonium hydroxide, an amine compound, and a nonionic surfactant, wherein the nonionic surfactant comprises at least two selected from the group consisting of a first nonionic surfactant represented by the following chemical formula 1, wherein n is 1 or 2; a second nonionic surfactant represented by the following chemical formula 1, wherein n is 3 or 5; and a third nonionic surfactant represented by the following chemical formula 1, wherein n is 6 or 8. [ka] (In the above Chemical Formula 1, R is a C3 to C18 linear or branched alkyl group, a C3 to C18 cyclic alkyl group, or a C6 to C18 aryl group.)

[0009] 2. The silicon etching solution composition according to item 1, wherein the nonionic surfactant comprises the second nonionic surfactant and further comprises at least one of the first nonionic surfactant and the third nonionic surfactant.

[0010] 3. The silicon etching solution composition according to item 1, wherein the content of the nonionic surfactant is 0.01% by weight to 0.2% by weight, based on the total weight of the silicon etching solution composition.

[0011] 4. The silicon etching solution composition according to item 2, wherein the nonionic surfactant comprises the first nonionic surfactant and the second nonionic surfactant, and the ratio of the weight of the first nonionic surfactant to the weight of the second nonionic surfactant is 0.1 to 0.2.

[0012] 5. The silicon etching solution composition according to item 4, wherein the ratio of the weight of the first nonionic surfactant to the weight of the second nonionic surfactant is 0.12 to 0.17.

[0013] 6. The silicon etching solution composition according to item 2, wherein the nonionic surfactant comprises the second nonionic surfactant and the third nonionic surfactant, and the ratio of the weight of the third nonionic surfactant to the weight of the second nonionic surfactant is 0.08 to 0.17.

[0014] 7. The silicon etching solution composition according to item 6, wherein the ratio of the weight of the third nonionic surfactant to the weight of the second nonionic surfactant is 0.10 to 0.15.

[0015] 8. The silicon etching solution composition according to item 1, wherein the nonionic surfactant is represented by chemical formula 1 and does not include a nonionic surfactant in which n is 8.

[0016] 9. The silicon etching solution composition according to item 1, wherein R is a phenyl group, a naphthyl group, a methylphenyl group, or an octylphenyl group.

[0017] 10. The silicon etching solution composition according to item 1, wherein the content of the quaternary alkylammonium hydroxide is 1% by weight to 20% by weight, based on the total weight of the silicon etching solution composition.

[0018] 11. The silicon etching solution composition according to item 1, wherein the content of the amine compound is 1 wt % to 30 wt % relative to the total weight of the silicon etching solution composition.

[0019] 12. A pattern formation method comprising the steps of: forming a silicon-containing film on a substrate; partially forming a silicon protective film on the silicon-containing film; and etching the silicon-containing film with the silicon etching solution composition according to item 1.

[0020] 13. The pattern forming method according to item 12, wherein the silicon protective film is used as an etching mask.

[0021] 14. The pattern forming method according to item 12, wherein the step of etching the silicon-containing film includes etching the silicon-containing film to form a gate pattern. [Effects of the Invention]

[0022] The silicon etchant composition according to an exemplary embodiment of the present invention may include two or more nonionic surfactants having different hydrophilic group lengths, each of which may perform a different function in improving the etching rate of the silicon etchant composition, improving etching uniformity, or improving the surface roughness of the object to be etched.

[0023] The silicon etching solution composition contains a combination of two or more nonionic surfactants having different functions, which can increase the etching rate of the silicon etching solution composition, enable uniform etching of an object to be etched having a narrow pattern size (e.g., a silicon wafer), and reduce the surface roughness of the object to be etched after etching and the etching residue on the surface of the object to be etched.

[0024] The nonionic surfactant may include a second nonionic surfactant having a medium-length hydrophilic group, and a first nonionic surfactant or a third nonionic surfactant having a long or short hydrophilic group in a predetermined content ratio, thereby further improving the etching rate and etching uniformity of the silicon etching solution composition.

[0025] Silicon etchant compositions according to exemplary embodiments of the present invention can be used to form highly reliable nanoscale semiconductor device patterns. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating a pattern formation method according to an exemplary embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating a patterning method according to an exemplary embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view illustrating a patterning method according to an exemplary embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating a patterning method according to an exemplary embodiment. [Figure 5] FIG. 5 is a schematic cross-sectional view illustrating a patterning method according to an exemplary embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view illustrating a pattern formation method according to an exemplary embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view illustrating a patterning method according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] A silicon etchant composition according to an embodiment of the present invention may include a quaternary alkylammonium hydroxide, an amine compound, and two or more nonionic surfactants. The silicon etchant composition can rapidly and uniformly etch a silicon layer while leaving substantially no etching residue on the surface to be etched.

[0028] The present invention also provides a pattern formation method using the etching solution composition.

[0029] The term "silicon" as used in this application can refer to polysilicon and amorphous silicon.

[0030] Hereinafter, embodiments of the present invention will be described in detail.

[0031] The quaternary alkylammonium hydroxide can function as a main etching agent for removing a film to be etched, such as a silicon film, during an etching process. For example, the quaternary alkylammonium hydroxide dissociates in a solution to generate hydroxide ions, thereby increasing the pH of the etching solution composition and etching the silicon film.

[0032] The quaternary alkyl ammonium hydroxide may include a compound represented by the following Chemical Formula 2:

[0033] [ka]

[0034] In Chemical Formula 2, R1, R2, R3, and R4 are each independently an alkyl group or aryl group having 1 to 8 carbon atoms, and in some embodiments, may be an alkyl group having 1 to 4 carbon atoms. When the carbon numbers of R1, R2, R3, and R4 are within the above ranges, the dissociation of hydroxide ions from the quaternary alkylammonium hydroxide can be promoted. The alkyl group or aryl group may contain a substituent.

[0035] The term "substituted" as used herein may mean that any hydrogen in a hydrocarbon group is replaced with at least one selected from the group consisting of a halogen atom, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 alkoxy group, a C1-C6 acetyl group, a C6-C12 phenoxy group, a C6-C12 aryl group, a C1-C6 alkylsulfonyl group, a sulfonic acid group, a hydroxy group, a nitro group, an amino group, an alkylamine group represented by -NR3R4R5 (R3, R4, and R5 are each independently hydrogen or a C1-C6 alkyl group), and a cyano group.

[0036] For example, the quaternary alkylammonium hydroxide may include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, benzyltriethylammonium hydroxide, diethyldimethylammonium hydroxide, methyltributylammonium hydroxide, choline hydroxide, etc. These may be used alone or in combination of two or more.

[0037] In an exemplary embodiment, the content of the quaternary alkylammonium hydroxide may be about 1 wt % to 20 wt % based on the total weight of the etching solution composition. Within this range, the degree of dissociation of hydroxide ions or the amount dissociated from the composition can be sufficiently ensured, thereby improving etching performance. In one embodiment, the content of the quaternary alkylammonium hydroxide may be about 5 wt % to 10 wt % based on the total weight of the etching solution composition.

[0038] The amine-based compound can adjust or maintain the pH of the etching solution composition and can be added as an etching accelerator. For example, the amine-based compound can promote dissociation or generation of hydroxide ions in the composition, thereby improving the hydrophilicity or wettability of a silicon film. It can also promote the removal of surface hydrogen gas generated during etching of a silicon film.

[0039] The amine compound may or may not contain a hydroxy group. When the amine compound contains a hydroxy group, the concentration of hydroxide ions in the etching solution composition can be increased, thereby improving the etching rate of the etching solution composition. The amine compound may be linear or cyclic.

[0040] For example, amine compounds containing a hydroxy group include 1-amino-2-propanol, 2-amino-1-butanol, 3-amino-1-propanol, 3-amino-1,2-propanediol, 2,3-butanediol, methyldiethanolamine, propanolamine, ethanolamine, diethanolamine, N-methylethanolamine, N-methyldiethanolamine, 2-amino-3-methyl-1-butanol, 3-amino-2,2-dimethyl-1-propanol, tris(hydroxymethyl)aminomethane, 2-amino-2 -Methyl-1,3-propanediol, 3-methylamino-1-propanol, 2-dimethylamino-2-methyl-1-propanol, 1-dimethylamino-2-propanol, 3-dimethylamino-1-propanol, 2-dimethylamino-1-propanol, 2-diethylamino-1-propanol, 2-diethylamino-1-ethanol, 2-ethylamino-1-ethanol, 1-(dimethylamino)2-propanol, N-propyldiethanolamine, N-isopropyldiethanolamine, N-(2-methylpropyl) Examples of suitable amines include diethanolamine, Nn-butyldiethanolamine, Nt-butylethanolamine, N-cyclohexyldiethanolamine, 2-(dimethylamino)ethanol, 2-diethylaminoethanol, 2-dipropylaminoethanol, 2-butylaminoethanol, 2-t-butylaminoethanol, 2-cycloaminoethanol, 2-amino-2-pentanol, 2-[bis(2-hydroxyethyl)amino]-2-methyl-1-propanol, 2-[bis(2-hydroxyethyl)amino]-2-propanol, N,N-bis(2-hydroxypropyl)ethanolamine, 2-amino-2-methyl-1-propanol, tris(hydroxymethyl)aminomethane, and triisopropanolamine. These may be used alone or in combination of two or more.

[0041] For example, amine compounds not containing a hydroxy group may include 1,2-diaminopropane, diethylenetriamine, isopropylamine, triethylamine, trimethylamine, methylamine, ethylamine, aniline (aminobenzene), 2-aminopentane, diethylamine, N-dodecyldiethylamine, etc. These may be used alone or in combination of two or more.

[0042] The cyclic amine compound may include a substituted or unsubstituted nitrogen-containing heterocycle, such as a substituted or unsubstituted nitrogen-containing bridged bicyclic compound or a substituted or unsubstituted nitrogen-containing heteroaryl group.

[0043] For example, the cyclic amine compound may include trimethylpyridine, dimethylpyridine, and the like.

[0044] The cyclic amine compound may include azabicyclo compounds, diazabicyclo compounds, triazabicyclo compounds, etc. as a nitrogen atom-containing bridged bicyclic compound.

[0045] In some embodiments, the azabicyclo compound can include an azabicycloalkane or azabicycloalkene, each having 3 to 13 carbon atoms. The diazabicyclo compound can include a diazabicycloalkane or diazabicycloalkene, each having 2 to 12 carbon atoms. The triazabicyclo compound can include a triazabicycloalkane or triazabicycloalkene, each having 2 to 11 carbon atoms.

[0046] For example, the cyclic amine compound may have one of azabicyclo-, diazabicyclo-, and triazabicyclo- structures, and may include one or more structures selected from the group consisting of butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, nonene, decene, and undecene, depending on the number of carbon atoms and bonds.

[0047] Examples of the cyclic amine compounds include monoazabicyclo compounds such as 8-azabicyclo[3.2.1]octane, 1,8-azabicyclo[6.3.2]tridecane, and 11-azabicyclo[4.4.1]undecane-1,3,5,7,9-pentene; 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, 2,8-diazabicyclo[4.3.0]nonane, and 1,4-diazabicyclo[4.3. 0]nonane, 1,4-diazabicyclo[3.2.2]nonane, 1,4-diazabicyclo[2.2.2]octane, 1,4-diazabicyclo[3.2.1]octane, 3-benzyl-3,8-diazabicyclo[3.2.1]octane, and other diazabicyclo-based compounds; 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and other triazabicyclo-based compounds. These can be used alone or in combination of two or more.

[0048] In exemplary embodiments, the content of the amine-based compound may be about 1 wt % to 30 wt % based on the total weight of the etching solution composition. In some embodiments, the content of the amine-based compound may be about 5 wt % to 15 wt % based on the total weight of the etching solution composition. Within this range, the amine-based compound can hydrophilize the surface to be etched, thereby improving the etching rate.

[0049] The silicon etchant composition may include a nonionic surfactant, which may reduce the surface tension of the silicon film and suppress bubbles that may occur during the etching process.

[0050] According to an exemplary embodiment, the nonionic surfactant may include at least two selected from the group consisting of a first nonionic surfactant represented by the following chemical formula 1, where n is 1 to 2; a second nonionic surfactant represented by the following chemical formula 1, where n is 3 to 5; and a third nonionic surfactant represented by the following chemical formula 1, where n is 6 to 8.

[0051] [ka]

[0052] In the above Chemical Formula 1, R may be a C3 to C18 linear or branched alkyl group, a C3 to C18 cyclic alkyl group, or a C6 to C18 aryl group.

[0053] The branched alkyl group, cyclic alkyl group, and aryl group may each independently be substituted or unsubstituted.

[0054] In Formula 1, R may be a hydrophobic group. The hydrophobic group can promote adsorption to the silicon film surface and remove or desorb bubbles generated during the etching process. To improve adsorption to the silicon film surface, the hydrophobic group may have a relatively low molecular weight structure. For example, R may be a linear or branched alkyl group, a cyclic alkyl group, or an aryl group having 10 or fewer carbon atoms.

[0055] For example, R may be a C3 to C18 linear or branched alkyl group such as propyl, isopropyl, butyl, isobutyl, sec-butyl, tetrabutyl, ethylhexyl, decyl, lauryl, isotridecyl, cetyl, or stearyl; a C3 to C18 cyclic alkyl group such as cyclopentyl, cyclohexyl, cycloheptyl, or cyclooctyl; or a C6 to C18 aryl group such as phenyl, naphthyl, methylphenyl, or octylphenyl. In an exemplary embodiment, R may be a phenyl, naphthyl, methylphenyl, or octylphenyl group. These may be used alone or in combination of two or more.

[0056] In some embodiments, R may be a C3 to C18 cyclic alkyl group or a C6 to C18 aryl group. In one embodiment, R may be a C6 to C18 aryl group, such as a phenyl group.

[0057] In Formula 1, the polyethylene glycol group may be a hydrophilic group. The hydrophilic group can improve the penetration of the nonionic surfactant in the etching solution composition. For example, the nonionic surfactant can be adsorbed onto the surface of a silicon membrane while the hydrophilic group can promote the penetration of hydroxide ions.

[0058] The properties of the nonionic surfactant can vary depending on the repeating number (n) of the polyethylene glycol group. For example, a first nonionic surfactant in which n is 1 to 2 has a short hydrophilic group, does not inhibit contact between the surface of the object to be etched and the etching solution composition, and can improve the etching rate.

[0059] The second nonionic surfactant in which n is 3 to 5 can hydrophilize the surface of the object to be etched, and can improve the pattern penetration power and etching performance of the etching solution composition.

[0060] The third nonionic surfactant in which n is 6 to 8 has a high efficiency of hydrophilizing the surface of the object to be etched, and can reduce the surface roughness of the object to be etched.

[0061] The nonionic surfactant may include two or more of the first nonionic surfactant and the second nonionic surfactant. By using two or more nonionic surfactants having different lengths of hydrophilic group, the performance of the etching solution composition can be improved in many ways.

[0062] In exemplary embodiments, the nonionic surfactant comprises the second nonionic surfactant and can further comprise the first nonionic surfactant or the third nonionic surfactant. In one embodiment, the nonionic surfactant can comprise the first nonionic surfactant, the second nonionic surfactant, and the third nonionic surfactant.

[0063] According to exemplary embodiments, the content of the nonionic surfactant may be 0.01 wt % to 0.2 wt % based on the total weight of the composition. According to some embodiments, the content of the nonionic surfactant may be 0.05 wt % to 0.15 wt % based on the total weight of the composition. Within this range, the surface tension of the surface of the object to be etched can be effectively reduced, thereby increasing the pattern penetration ability of the etching solution composition.

[0064] According to exemplary embodiments, the weight ratio of the first nonionic surfactant to the second nonionic surfactant may be 0.1 to 0.2. According to some embodiments, the weight ratio of the first nonionic surfactant to the second nonionic surfactant may be 0.12 to 0.17. Within this range, the etching rate of the etching solution composition can be improved while preventing an increase in the surface roughness of the object to be etched.

[0065] According to exemplary embodiments, the weight ratio of the third nonionic surfactant to the second nonionic surfactant may be 0.08 to 0.17. According to some embodiments, the weight ratio of the third nonionic surfactant to the second nonionic surfactant may be 0.10 to 0.15. Within this range, the pattern penetration ability of the etching solution composition can be prevented from decreasing. Furthermore, the nonionic surfactant is not excessively adsorbed onto the surface of the object to be etched, preventing a decrease in the etching rate.

[0066] According to an exemplary embodiment, the nonionic surfactant may not include a nonionic surfactant represented by Chemical Formula 1 where n is 8. In the case of a nonionic surfactant in Chemical Formula 1 where n is 8, the length of the hydrophilic group is long and it may be excessively adsorbed onto the surface of the object to be etched, thereby acting as an etching inhibitor.

[0067] The etching solution composition may contain excess or residual water (e.g., deionized water). The terms "excess" and "residual" used herein may refer to a variable amount that varies depending on the addition of components or formulations. For example, it may refer to the amount remaining excluding the quaternary alkylammonium hydroxide, amine compound, and nonionic surfactant, or the amount remaining excluding the quaternary alkylammonium hydroxide, amine compound, nonionic surfactant, and other additives.

[0068] In some embodiments, the water may include deionized water for semiconductor processing, for example, deionized water having a resistivity value of 18 MΩ / cm or more.

[0069] The etching solution composition may further contain additives within a range that does not impair the etching performance, surface tension reduction, bubble removal effects, etc. of the quaternary alkylammonium hydroxide, amine compound, and nonionic surfactant. The additives may include, for example, an etching accelerator, a corrosion inhibitor, a pH adjuster, etc.

[0070] In some embodiments, the pH of the silicon etchant composition can be adjusted to a range of about 11 to 14. Within this pH range, damage to insulating structures, semiconductor patterns, substrates, and the like other than the silicon film, which is the film to be etched, can be suppressed.

[0071] In some embodiments, the etching solution composition can be prepared as a two-component composition. For example, a preliminary etching solution composition can be prepared by mixing an amine compound and a nonionic surfactant. The preliminary etching solution composition or the mixture of additives for the silicon film etching solution can be mixed with an aqueous quaternary alkylammonium hydroxide solution. This allows the silicon etching solution composition having a target content composition to be prepared from the relatively concentrated preliminary etching solution composition.

[0072] This allows the amine compound and the nonionic surfactant to be mixed first and stabilized, thereby preventing the amine compound and the nonionic surfactant from coming into contact with the quaternary alkylammonium hydroxide first and inhibiting their activity.

[0073] According to exemplary embodiments, the etching rate of the silicon etchant composition for a single crystal silicon film may be 4000 Å / min or more. In some embodiments, the etching rate of the silicon etchant composition for a single crystal silicon film may be 5000 Å / min or more, or 6000 Å / min or more. Within this range, the etching process can be effectively controlled while improving the efficiency of the etching process and product productivity.

[0074] Etching of a silicon film using the etching solution composition can be performed by a method commonly known in the art. For example, a method using deposition, spraying, or both deposition and spraying in a batch-type or single-type etching apparatus can be used. However, the etching method and conditions are not particularly limited and can be adjusted as appropriate by those skilled in the art.

[0075] 1 to 7 are schematic cross-sectional views for explaining a pattern formation method according to an exemplary embodiment.

[0076] However, the etching solution compositions according to the exemplary embodiments are not limited to the processes of FIGS. 1 to 7, but can be used in processes for forming various structures or patterns such as wiring, contacts, and gates.

[0077] 1 to 3 are schematic cross-sectional views illustrating a method for manufacturing a semiconductor device according to an exemplary embodiment.

[0078] Referring to FIG. 1, an insulating film 110 may be formed on the substrate 100 , and a silicon-containing film 120 may be formed on the insulating film 110 .

[0079] The substrate 100 may include a semiconductor material such as single crystal silicon, single crystal germanium, or polysilicon.

[0080] The insulating film 110 may be formed to include an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, etc. For example, the insulating film 110 may be formed by a chemical vapor deposition (CVD) process, a sputtering process, a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, etc.

[0081] The silicon-containing film 120 may include single-crystal silicon, polysilicon, or amorphous silicon.

[0082] 2, a silicon protective layer 130 may be formed on the silicon-containing layer 120. The silicon protective layer 130 may be formed to include a silicon oxide layer or a silicon nitride layer. For example, the silicon protective layer 130 may be formed by a CVD process, a sputtering process, a PVD process, an ALD process, etc.

[0083] The mask pattern 132 may be formed by partially etching the silicon protective layer 130. For example, a portion of the silicon protective layer 130 may be partially etched until a portion of the top surface of the silicon-containing layer 120 is exposed.

[0084] 3, the silicon-containing film 120 can be partially removed using the etchant composition according to the above exemplary embodiment, thereby forming a gate pattern 122 from the silicon-containing film 120.

[0085] 4 to 7 are schematic cross-sectional views illustrating a pattern formation method according to an exemplary embodiment, specifically, a method for forming shallow trench isolation (STI) according to an exemplary embodiment.

[0086] Referring to FIG. 4, a silicon protective layer 210 may be formed on a substrate 200 .

[0087] The substrate 200 may be a silicon substrate including single crystal silicon, polysilicon, or amorphous silicon.

[0088] The silicon protective layer 210 may include a silicon oxide layer or a silicon nitride layer, and may be formed by a chemical vapor deposition (CVD) process, a sputtering process, a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, etc. so that the silicon protective layer covers the upper surface of the substrate 200.

[0089] 5, the silicon passivation layer 210 may be partially etched to form a mask pattern 215. For example, a portion of the silicon passivation layer 210 may be etched until a portion of the top surface of the substrate 200 is exposed.

[0090] 6, the etchant composition according to the above-described exemplary embodiment can be used to partially etch the upper portion of the substrate 200, thereby forming a trench 220 inside the substrate 200.

[0091] As described above, the etching solution composition can be used to prevent etching of the mask pattern 215 and selectively etch only the upper portion of the substrate 200. This allows, for example, in a nanoscale fine etching process, to remove the upper portion of the substrate 200 without etching defects, thereby enabling a highly reliable etching process.

[0092] Referring to FIG. 7, an insulating pattern 230 may be formed inside the trench 220 .

[0093] The insulating pattern 230 may be formed to include an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, etc. For example, the insulating material may be formed to fill the inside of the trench 220 by a CVD process, a sputtering process, a PVD process, an ALD process, etc.

[0094] Below, preferred examples are presented to aid in understanding the present invention. However, these examples are merely illustrative of the present invention and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications to the examples are possible within the scope and technical spirit of the present invention, and it is natural that such changes and modifications also fall within the scope of the appended claims. [Example]

[0095] Examples and Comparative Examples Silicon etching solution compositions were prepared according to the formulations shown in Tables 1 and 2 below. The remaining amount of water was added to make the composition 100 parts by weight.

[0096] [Table 1]

[0097] [Table 2]

[0098] The ingredients shown in Tables 1 and 2 above are as follows: A-1: Tetramethylammonium hydroxide A-2: Tetraethylammonium hydroxide B-1: Polyethylene glycol phenyl ether (n = approx. 2) B-2: Polyethylene glycol phenyl ether (n = approx. 4) B-3: Polyethylene glycol phenyl ether (n = approx. 6) B-4: Polyethylene glycol phenyl ether (n = approx. 8) B-5: Polyethylene glycol beta-naphthyl ether (n = approx. 4) B-6: Polyethylene glycol lauryl ether (n = approx. 4) B-7: Polyethylene glycol tert-octyl phenyl ether (n = approx. 10) B-8: Polyethylene glycol oleyl ether (n = approx. 4) C-1: 1-amino-2-propanol C-2: 2,3-butanediol

[0099] Experimental Example 1: Evaluation of etching rate for silicon A silicon wafer on which silicon was deposited to a thickness of 6000 Å was cut into a 1.5 cm x 1.5 cm specimen, which was then immersed in the etching solution compositions of the Examples and Comparative Examples at 70°C and 400 rpm for 30 seconds.

[0100] The specimen was then removed, washed with water, and dried in air. The thickness of the silicon film was then measured using an ellipsometer. The etching rate of the silicon film was then calculated from the change in film thickness before and after immersion. The etching rate was evaluated according to the following criteria:

[0101] <Evaluation criteria> ◎◎: Etching speed is 6000Å / min or more ◎: Etching speed is less than 6000Å / min to 5000Å / min or more ○: Etching speed is less than 5000 Å / min to 4000 Å / min or more △: Etching speed is less than 4000Å / min to 3000Å / min or more X: Etching rate is less than 3000Å / min

[0102] Experimental Example 2: Evaluation of surface roughness after silicon etching Atomic Force Microscopy (AFM) was used to measure the surface roughness (Rq, Root Mean Square) of the silicon wafer after etching in Experimental Example 1. The surface roughness was evaluated according to the following criteria.

[0103] <Evaluation criteria> ◎: 10Å or less ○: Over 10Å to 30Å △: Over 30Å to 50Å X: Over 50Å

[0104] Experimental Example 3: Evaluation of etching uniformity of silicon patterns The etching rates for two types of patterns with an aspect ratio of approximately 20 (Pattern A: CD approximately 50 nm, Pattern B: CD approximately 100 nm) were compared to evaluate the etching uniformity due to the difference in the penetration power of the etching composition.

[0105] The silicon etching rate for each pattern was determined, and the etching uniformity was calculated according to the following formula, and the etching uniformity was evaluated according to the following criteria.

[0106] [formula] Etching uniformity=(etching rate of pattern B−etching rate of pattern A) / (etching rate of pattern B+etching rate of pattern A)

[0107] <Evaluation criteria> ◎: 0.3 or less ○: Over 0.3 to 0.5 or less △: Over 0.5 to 0.7 or less X: Over 0.7

[0108] Experimental Example 4: Evaluation of nonionic surfactant residues To evaluate the residue on the silicon surface, the etching evaluation was completed and the specimens were subjected to FT-IR analysis. The polyethylene oxide derived from the nonionic surfactant was analyzed and the residue of the nonionic surfactant was evaluated according to the following criteria.

[0109] <Evaluation criteria> X: No residue O: Residue present

[0110] The results of the evaluation are shown in Tables 3 and 4 below.

[0111] [Table 3]

[0112] [Table 4]

[0113] As shown in Tables 1 to 4, in the examples, an increased etching rate was ensured, no residue was generated on the surface of the etching target, and the surface roughness of the silicon wafer after etching was reduced, improving the uniformity of the pattern etching.

[0114] In Comparative Examples 1 to 8, in which a silicon etching solution containing one type of nonionic surfactant was used, the uniformity of silicon etching decreased, the etching rate decreased excessively, and residues were generated on the wafer surface.

[0115] In Comparative Example 9, which used an etching solution composition that contained the second nonionic surfactant but did not contain the first nonionic surfactant or the third nonionic surfactant, the etching rate decreased and surface residue was also generated.

[0116] In Comparative Examples 10 and 11, in which a silicon etching solution composition containing no quaternary alkylammonium hydroxide or amine compound was used, the etching rate, surface roughness, and pattern etching uniformity all deteriorated.

Claims

1. The composition contains a quaternary alkyl ammonium hydroxide, an amine compound, and a nonionic surfactant, The silicon etching solution composition includes at least one nonionic surfactant selected from the group consisting of a second nonionic surfactant represented by the following chemical formula 1, wherein n is 3 to 5, a first nonionic surfactant represented by the following chemical formula 1, wherein n is 1 to 2, and a third nonionic surfactant represented by the following chemical formula 1, wherein n is 6 to 8. 【Chemical 1】 (In the above Chemical Formula 1, R is a C3 to C18 linear or branched alkyl group, a C3 to C18 cyclic alkyl group, or a C6 to C18 aryl group.)

2. 2. The silicon etching liquid composition according to claim 1, wherein the content of the nonionic surfactant is 0.01 wt % to 0.2 wt % based on the total weight of the silicon etching liquid composition.

3. the nonionic surfactant comprises the first nonionic surfactant and the second nonionic surfactant; 2. The silicon etchant composition of claim 1, wherein a ratio of a weight of the first nonionic surfactant to a weight of the second nonionic surfactant is 0.1 to 0.

2.

4. 4. The silicon etchant composition of claim 3, wherein a ratio of a weight of the first nonionic surfactant to a weight of the second nonionic surfactant is 0.12 to 0.

17.

5. the nonionic surfactants include the second nonionic surfactant and the third nonionic surfactant; 2. The silicon etchant composition of claim 1, wherein a ratio of a weight of the third nonionic surfactant to a weight of the second nonionic surfactant is 0.08 to 0.

17.

6. 6. The silicon etchant composition according to claim 5, wherein a ratio of a weight of the third nonionic surfactant to a weight of the second nonionic surfactant is 0.10 to 0.

15.

7. 2. The silicon etchant composition of claim 1, wherein the nonionic surfactant does not include a nonionic surfactant represented by Chemical Formula 1 in which n is 8.

8. 2. The silicon etching solution composition according to claim 1, wherein in Chemical Formula 1, R is a phenyl group, a naphthyl group, a methylphenyl group, or an octylphenyl group.

9. 2. The silicon etching solution composition according to claim 1, wherein the content of the quaternary alkylammonium hydroxide is 1% by weight to 20% by weight, based on the total weight of the silicon etching solution composition.

10. 2. The silicon etching solution composition according to claim 1, wherein the content of the amine compound is 1 wt % to 30 wt % based on the total weight of the silicon etching solution composition.

11. forming a silicon-containing film on a substrate; forming a silicon protection film partially on the silicon-containing film; and etching the silicon-containing film with the silicon etchant composition of claim 1.

12. The pattern formation method according to claim 11 , wherein the silicon protective film is used as an etching mask.

13. 12. The pattern forming method of claim 11, wherein the step of etching the silicon-containing film comprises etching the silicon-containing film to form a gate pattern.

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