KR20150109089A - Texture etching solution composition and texture etching method of crystalline silicon wafers - Google Patents

Abstract

The present invention relates to a texture-etching solution composition for crystalline silicon wafers and a texture-etching method and, more specifically, to a texture-etching solution composition for crystalline silicon wafers and a texture-etching method comprising: an alkali compound; a compound of chemical formula 1; and a polysaccharide. Thus, the present invention prevents over-etching caused by an alkali compound by controlling differences in etching speed with respect to a direction of the silicon crystalline, and thus quality deviations of the texture of the surfaces of crystalline silicon wafers by position are minimized, in other words, the amount of absorbed sunlight by improving the uniformity of the texture structure can be maximized.

Description

TECHNICAL FIELD [0001] The present invention relates to a texture etching liquid composition for a crystalline silicon wafer and a texture etching method for a crystalline silicon wafer,

TECHNICAL FIELD The present invention relates to a texture etchant composition of a crystalline silicon wafer and a texture etching method.

In recent years, solar cells, which are rapidly spreading, are electronic devices that convert solar energy, which is a clean energy source, into direct electricity as a next-generation energy source. P-type silicon semiconductor doped with boron is used as silicon, And a PN junction semiconductor substrate in which an N-type silicon semiconductor layer is formed.

When a light such as sunlight is irradiated to a substrate formed with an electric field by PN junction, electrons (-) and holes (+) in the semiconductor are excited to move freely in the semiconductor, and the electric field generated by the PN junction When it comes in, the electrons (-) lead to the N-type semiconductor and the positive (+) lead to the P-type semiconductor. When an electrode is formed on the surface of a p-type semiconductor and an n-type semiconductor and an electron flows to an external circuit, a current is generated. This principle converts solar energy into electrical energy. Therefore, in order to increase the conversion efficiency of solar energy, the electrical output per unit area of the PN junction semiconductor substrate must be maximized. For this, the reflectance should be lowered and the light absorption amount should be maximized. In consideration of this point, the surface of the silicon wafer for a solar cell constituting the PN junction semiconductor substrate is formed into a fine pyramid structure and the antireflection film is processed. The surface of a silicon wafer textured with a fine pyramid structure lowers the reflectance of incident light having a wide wavelength band to increase the intensity of the absorbed light, thereby enhancing the performance, i.e., efficiency, of the solar cell.

US Pat. No. 4,137,123 discloses a method of texturing a surface of a silicon wafer with a fine pyramid structure by adding 0.5 to 10 wt. % Of silicon is dissolved in a solvent. However, this etchant may cause pyramid formation failure to increase the light reflectance and lower the efficiency.

European Patent No. 0477424 discloses a texture etching method in which oxygen is supplied to a texture etchant in which silicon is dissolved in water of ethylene glycol, potassium hydroxide and a residual amount, that is, an air-bearing process is performed. However, this etching method has a disadvantage in that pyramid formation failure is caused to increase the light reflectance and the efficiency, and also requires installation of a separate air-rating equipment.

Korean Patent No. 0180621 discloses a texture etching solution mixed at a ratio of 0.5-5% of a potassium hydroxide solution, 3-20% by volume of isopropyl alcohol and 75-96.5% by volume of deionized water, and US Patent No. 6,451,218 Discloses a texturing etch solution comprising an alkaline compound, isopropyl alcohol, water soluble alkaline ethylene glycol and water. However, since these etching solutions contain isopropyl alcohol having a low boiling point, they are not economical from the viewpoint of productivity and cost because they must be added to the etching solution in the texturing process, and the temperature gradient of the etching solution is generated due to the added isopropyl alcohol, And the uniformity of the texture may be deteriorated.

U.S. Patent No. 4,137,123 European Patent No. 0477424 Korea Patent No. 0180621

In forming a fine pyramid structure on the surface of a crystalline silicon wafer, the present invention controls the difference in the etching rate with respect to the direction of the silicon crystal to prevent over etching by the alkali compound, thereby minimizing the quality deviation of the texture per position, Which is an object of the present invention, to provide a texture etching liquid composition for a crystalline silicon wafer.

Another object of the present invention is to provide a texture etchant composition for a crystalline silicon wafer which does not require the addition of a separate etchant component during the etching process and does not cause a temperature gradient during etching.

Another object of the present invention is to provide a texture etching method using the texture etching liquid composition of the crystalline silicon wafer.

1. Alkali compounds; A compound of the formula 1 below; ≪ / RTI > and a polysaccharide.

[Chemical Formula 1]

(Wherein R ₁ is, independently of each other, an alkyl group having 1 to 10 carbon atoms, a phenyl group or an allyl group,

R ₂ is a hydrogen atom or a methyl group,

n is an integer of 1 to 3,

M is ^{H, K +, Na +,} NH 4 +, N (CH 3) +, N (CH 2 CH 3) 4 +, N (C 2 H 4 CH 3) + or N (C ₃ H ₆ CH ₃ ) ⁺ ).

2. The method of claim 1, wherein the compound of Formula 1 is selected from the group consisting of 2- (2-methoxyethoxy) acetic acid, potassium 2- (2-methoxyethoxy) acetate, sodium 2- (2-methoxyethoxy) , 2- (2-ethoxyethoxy) ethoxy) acetic acid, potassium 2- (2- (2-ethoxyethoxy) ethoxy) Methoxy) ethoxy) acetate, sodium 2- (2- (2-butoxyethoxy) ethoxy) acetate and tetraethylammonium 2- (2- (2- (hexyloxy) ethoxy) ethoxy) acetate Wherein the etching solution is at least one selected from the group consisting of silicon nitride, silicon nitride, and silicon nitride.

3. The composition of claim 1, wherein the compound of Formula 1 is contained in an amount of 10 ^-9 to 0.1% by weight based on the total weight of the etchant composition.

4. The composition of claim 1, wherein the alkaline compound is at least one selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, tetrahydroxymethylammonium, and tetrahydroxyethylammonium.

5. The polysaccharide of claim 1, wherein the polysaccharide is at least one selected from the group consisting of a glucan compound, a fructan compound, a mannan compound, a galactan compound, Wherein the etchant composition of the textured silicon wafer comprises:

6. The process of claim 1, wherein the fine powder silica; A colloidal silica solution stabilized with Na ₂ O; A colloidal silica solution stabilized with K ₂ O; A colloidal silica solution stabilized with an acidic solution; A colloidal silica solution stabilized with NH ₃ ; A colloidal silica solution stabilized with at least one organic solvent selected from the group consisting of ethyl alcohol, propyl alcohol, ethylene glycol, methyl ethyl ketone and methyl isobutyl ketone; Liquid sodium silicate; Liquid potassium silicate; And at least one silica-containing compound selected from the group consisting of lithium silicate and liquid lithium silicate.

7. A method of etching a crystalline silicon wafer with an etchant composition according to any one of claims 1 to 6.

8. The method for etching a crystalline silicon wafer according to 7 above, wherein said etchant composition is sprayed onto a silicon wafer at a temperature of 50 to 100 DEG C for 30 seconds to 60 minutes.

9. The method of claim 7, wherein the silicon wafer is immersed in the etchant composition at a temperature of 50 to 100 DEG C for 30 seconds to 60 minutes.

According to the texture etchant composition and the texture etching method of the crystalline silicon wafer of the present invention, the difference in the etching rate with respect to the direction of the silicon crystal is controlled to prevent the overetching by the alkali compound, To maximize the absorption of sunlight by improving the uniformity of the texture.

In addition, since the etching solution composition of the crystalline silicon wafer of the present invention does not require the addition of a separate etching solution component in the texture process, a temperature gradient during etching is not generated, and a uniform quality texture structure can be obtained.

1 is an SEM photograph of the surface of a single crystal silicon wafer substrate etched using the etching solution composition for a texture of the crystalline silicon wafer of Example 3. Fig.
2 is an SEM photograph of the surface of a single crystal silicon wafer substrate etched using the etching solution composition for a texture of the crystalline silicon wafer of Example 1. Fig.
3 is an SEM photograph of the surface of a single crystal silicon wafer substrate etched using the etching solution composition for a texture of the crystalline silicon wafer of Comparative Example 1. Fig.

The present invention relates to an alkaline compound; A compound of formula 1; And a polysaccharide, it is possible to control the difference in etching rate with respect to the direction of the silicon crystal, thereby preventing the over etching by the alkali compound, thereby minimizing the quality deviation of the texture on the surface of the crystalline silicon wafer, i.e., improving the uniformity of the texture To a texture etching liquid composition and a texture etching method of a crystalline silicon wafer capable of maximizing absorption of sunlight.

Hereinafter, the present invention will be described in detail.

The texture etchant composition of the crystalline silicon wafer of the present invention comprises a compound of the following formula:

[Chemical Formula 1]

(Wherein R ₁ is, independently of each other, an alkyl group having 1 to 10 carbon atoms, a phenyl group or an allyl group,

R ₂ is a hydrogen atom or a methyl group,

n is an integer of 1 to 3,

M is ^{H, K +, Na +,} NH 4 +, N (CH 3) +, N (CH 2 CH 3) 4 +, N (C 2 H 4 CH 3) + or N (C ₃ H ₆ CH ₃ ) ⁺ ).

The compound of formula (1) according to the present invention can control the difference in the etching rate with respect to the direction of the silicon crystal to prevent the over etching by the alkali compound, thereby minimizing the quality deviation of the texture. In addition, by acting as a surfactant, the activity of the hydroxy ion [OH ^- ] in the texture etchant composition is controlled to reduce the difference in the etching rate between the Si ₁₀₀ direction and the Si ₁₁₁ direction, To prevent the bubble stick phenomenon from occurring by rapidly dropping the hydrogen bubble generated by the etching.

The compound of the formula (1) is not particularly limited and includes, for example, 2- (2-methoxyethoxy) acetic acid, potassium 2- (2-methoxyethoxy) , 2- (2-ethoxyethoxy) ethoxy) acetic acid, potassium 2- (2- (2-ethoxyethoxy) ethoxy) Ethoxy) acetate, sodium 2- (2- (2-butoxyethoxy) ethoxy) acetate, tetraethylammonium 2- (2- (2- (hexyloxy) ethoxy) ethoxy) acetate (2- (2-methoxyethoxy) ethoxy) acetate, sodium 2- (2-methoxyethoxy) acetate, 2- (2- (2-ethoxyethoxy) ethoxy) acetate, sodium 2- (2- (2-ethoxyethoxy) ethoxy) Ethoxy) acetate, tetraethylammonium 2- (2- (2- (hexyloxy) ethoxy) ethoxy) acetate, etc. Lt; / RTI > These may be used alone or in combination of two or more.

The compound of the formula (1) may be contained in an amount of 10 ^-9 to 0.1% by weight, preferably 10 ^-6 to 0.01% by weight, based on the total weight of the texture etching liquid composition of the crystalline silicon wafer. If the content is less than 10 ^-9 % by weight, the effect of preventing the etching may be insufficient. If the content is more than 0.1% by weight, the etching rate by the alkali compound may be rapidly lowered and it may be difficult to form the desired fine pyramid.

The texture etchant composition of the crystalline silicon wafer of the present invention further comprises an alkali compound.

The alkali compound can be used without limitation as long as it is an alkaline compound commonly used in the art as a component for etching the surface of a crystalline silicon wafer. Examples of the alkali compound that can be used include potassium hydroxide, sodium hydroxide, ammonium hydroxide, tetrahydroxymethylammonium, and tetrahydroxyethylammonium. Of these, potassium hydroxide and sodium hydroxide are preferable. These may be used alone or in combination of two or more.

The alkali compound may be contained in an amount of 0.1 to 20% by weight, preferably 1 to 5% by weight, based on the total weight of the texture etching liquid composition of the crystalline silicon wafer. When the content falls within the above range, the surface of the silicon wafer can be etched.

The texture etchant composition of the crystalline silicon wafer of the present invention further comprises a polysaccharide.

A polysaccharide is a saccharide in which two or more monosaccharides are linked by a glycosidic bond to form a large molecule. By preventing over etching and accelerated etching by an alkaline compound, a uniform fine pyramid is formed, and a hydrogen bubble generated by etching It is a component that prevents the bubble stick phenomenon by dropping rapidly from the silicon wafer surface.

Examples of the polysaccharide include a glucan compound, a fructan compound, a mannan compound, a galactan compound, or a metal salt thereof. Among them, a glucan compound and its metal salt (for example, , Alkali metal salts) are preferable. These may be used alone or in combination of two or more.

Examples of the glucan compound include cellulose, dimethylaminoethylcellulose, diethylaminoethylcellulose, ethylhydroxyethylcellulose, methylhydroxyethylcellulose, 4-aminobenzylcellulose, triethylaminoethylcellulose, cyanoethylcellulose, ethylcellulose, But are not limited to, cellulose, carboxymethylcellulose, carboxyethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, alginic acid, amylose, amylopectin, pectin, starch, dextrin,? -Cyclodextrin,? -Cyclodextrin, Cyclodextrin, methyl- beta -cyclodextrin, dextran, sodium dextran sulfate, saponin, glycogen, zymo acid, lentinan, sijofinan or metal salts thereof.

The polysaccharide may have an average molecular weight of 5,000 to 1,000,000, preferably 50,000 to 200,000.

The polysaccharide may be contained in an amount of 10 ^-9 to 0.5% by weight, preferably 10 ^-6 to 0.1% by weight, based on the total weight of the texture etching liquid composition of the crystalline silicon wafer. When the content falls within the above range, etching and etching acceleration can be effectively prevented. When the content is more than 0.5% by weight, the etching rate by the alkali compound is rapidly lowered and it is difficult to form the desired fine pyramid.

Alternatively, the texture etchant composition of the crystalline silicon wafer of the present invention may further comprise a silica-containing compound.

The silica-containing compound is physically adsorbed on the surface of the crystalline silicon wafer and serves as a kind of mask, thereby making the silicon wafer surface into a fine pyramid shape.

Examples of the silica-containing compound include a powder type, a colloid solution type, or a liquid silicate metal compound. Specifically, fine powder silica; A colloidal silica solution stabilized with Na ₂ O; A colloidal silica solution stabilized with K ₂ O; A colloidal silica solution stabilized with an acidic solution; A colloidal silica solution stabilized with NH ₃ ; A colloidal silica solution stabilized with at least one organic solvent selected from the group consisting of ethyl alcohol, propyl alcohol, ethylene glycol, methyl ethyl ketone and methyl isobutyl ketone; Liquid sodium silicate; Liquid potassium silicate; And liquid lithium silicate. These may be used alone or in combination of two or more.

The silica-containing compound may be contained in an amount of 0.00001 to 10% by weight, preferably 0.0001 to 1% by weight, based on 100% by weight of the total amount of the texture etching liquid composition of the crystalline silicon wafer. When the content falls within the above range, fine pyramid formation on the surface of the crystalline silicon wafer can be facilitated.

Alternatively, the texture etchant composition of the crystalline silicon wafer of the present invention may comprise a fatty acid or a metal salt thereof; And at least one additive selected from the group consisting of a polyoxyethylene (POE) compound, a polyoxypropylene (POP) compound, and a copolymer thereof, which are surfactants.

Fatty acids and their metal salts are used in combination with polysaccharides to prevent over-etching by alkaline compounds to form uniform fine pyramids and at the same time to quickly drop hydrogen bubbles generated by etching from the silicon wafer surface to prevent bubble sticking Lt; / RTI >

The fatty acid is a carboxylic acid of a hydrocarbon chain containing a carboxy group and specifically includes acetic acid, propionic acid, butyric acid, valeric acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, But are not limited to, stearic acid, arachidic acid, behenic acid, lignoceric acid, cetric acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid,? -Linolenic acid,? -Linolenic acid, dihomo- Oleic acid, elaidic acid, erucic acid, nerbonic acid, and the like. The metal salt of the fatty acid may be an ester reaction product of a fatty acid and a metal salt such as NaOH or KOH. These may be used alone or in combination of two or more.

The fatty acid and its metal salt may be contained in an amount of 10 ^-9 to 10% by weight, preferably 10 ^-6 to 1% by weight, based on the total weight of the texture etching liquid composition of the crystalline silicon wafer. When the content falls within the above range, etching can be effectively prevented.

And Si ₁₀₀ direction by controlling the activity ^of-a polyoxyethylene-based (POE) compounds, polyoxypropylene-based (POP) compounds and copolymers thereof is a hydroxy ion [OH] of the texture etching solution composition as a surface active agent having a hydroxy group Not only the difference in the etching rate with respect to the Si ₁₁₁ direction is reduced but also the wettability of the surface of the crystalline silicon wafer is improved to rapidly drop the hydrogen bubble generated by the etching to prevent the occurrence of the bubble stick phenomenon.

Examples of the polyoxyethylene (POE) surfactant include polyoxyethylene glycol, polyoxyethylene glycol methyl ether, polyoxyethylene monoallyl ether, polyoxyethylene neopentyl ether, polyethylene glycol mono (tristyrylphenyl) ether, polyoxyethylene Polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecyl ether, polyoxyethylene decyl ether, polyoxyethylene octyl ether, polyoxyethylene bisphenol-A, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, Ether, polyoxyethylene glycerin ether, polyoxyethylene nonylphenyl ether, polyoxyethylene benzyl ether, polyoxyethylene phenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene phenol ether, polyoxyethylene having 6 to 30 carbon atoms in the alkyl group Ethylene alkyl cyclohexyl ether, polyoxyethylene beta -naphthol ether, polyoxyethylene Ethylene castor ether (polyoxyethylene castor ether), polyoxyethylene hydrogenated castor ether (polyoxyethylene hydrogenated castor ether); Polyoxyethylene lauryl ester, polyoxyethylene stearyl ester, polyoxyethylene oleyl ester; Polyoxyethylene laurylamine, polyoxyethylene stearylamine, polyoxyethylenetraelamine, and the like. As the polyoxypropylene (POP) surfactant, polypropylene glycol can be mentioned. As a copolymer of a polyoxyethylene (POE) compound and a polyoxypropylene (POP) based compound, a polyoxyethylene-polyoxypropylene copolymer, a polyoxyethylene-polyoxypropylene decaneyl ether copolymer, a polyoxyethylene Polyoxyethylene-polyoxypropylene dodecanyl ether copolymer, polyoxyethylene-polyoxypropylene tetradecanyl ether copolymer, polyoxyethylene-polyoxypropylene 2-ethylhexyl ether copolymer Polyoxyethylene-polyoxypropylene lauryl ether copolymer, polyoxyethylene-polyoxypropylene stearyl ether copolymer, glycerin addition type polyoxyethylene-polyoxypropylene copolymer, ethylenediamine addition type polyoxyethylene-polyoxypropylene Copolymers and the like. These may be used alone or in combination of two or more.

The polyoxyethylene (POE) compound, the polyoxypropylene (POP) compound and the surfactant which is a copolymer thereof may be contained in an amount of 10 ^-9 to 10% by weight based on the total weight of the texture etching liquid composition of the crystalline silicon wafer, Is preferably 10 ^-6 to 1% by weight, more preferably 0.00001 to 0.1% by weight. When the content falls within the above range, it is possible to reduce a variation in the texture quality of the surface of the crystalline silicon wafer at each texture position.

The texture etchant composition of the crystalline silicon wafer according to the present invention may appropriately employ the above-mentioned components according to specific needs, and then add water to adjust the overall composition, so that the remaining amount of the entire composition is occupied by water. Preferably, the components are adjusted to have the aforementioned content ranges.

The kind of water is not particularly limited, but it is preferably deionized distilled water, more preferably deionized distilled water for semiconductor processing, and has a specific resistance value of 18 M OMEGA. Or more.

The texture etchant composition of the crystalline silicon wafer of the present invention, which comprises the above-described components, particularly includes the compound of the formula (1), thereby controlling the difference in the etching rate with respect to the direction of the silicon crystal, Thus, it is possible to maximize the amount of sunlight absorption by minimizing the quality deviation of the texture of the crystalline silicon wafer surface by position, that is, by improving the uniformity of the texture. In addition, there is no need to add a separate etching solution component in the texture etching process and there is no need to introduce an air-rating equipment, which is advantageous in terms of productivity and cost.

The texture etchant composition of the crystalline silicon wafer of the present invention can be applied to a general etching process, for example, a dip process, a spray process, and a sheet-process etching process.

The present invention provides a method of etching a crystalline silicon wafer using the texture etchant composition of the crystalline silicon wafer.

The method of texturing a crystalline silicon wafer includes the steps of depositing a crystalline silicon wafer on the texture etchant composition of the crystalline silicon wafer of the present invention or by spraying a textured etchant composition of the crystalline silicon wafer of the present invention onto a crystalline silicon wafer Step, or both of the above steps.

The number of times of deposition and spraying is not particularly limited, and the order of deposition and spraying is not limited.

The step of depositing, spraying or depositing and spraying can be carried out at a temperature of 50 to 100 캜 for 30 seconds to 60 minutes.

The texture etching method of the crystalline silicon wafer of the present invention as described above is not only economical in terms of initial production and processing cost but also requires no separate airrating equipment for supplying oxygen, Structure.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Example  And Comparative Example

Water was added to the components listed in Table 1 below to prepare an etching solution composition for a texture of a crystalline silicon wafer.

division Alkaline compound (1)
compound Polysaccharide compound Silica-containing compound Kinds content
(weight%) Kinds content
(ppm) Kinds content
(ppm) Kinds content
(ppm) Example 1 KOH 2 MDGCA 300 CMCNa 150 - - Example 2 KOH 2 MDGCA-K 2000 CMCNa 150 - - Example 3 KOH 2 MDGCA-K 1000 CMCNa 150 - - Example 4 KOH 2 MDGCA-K 500 CMCNa 150 - - Example 5 KOH 2 MDGCA-K 100 CMCNa 150 - - Example 6 KOH 2 MDGCA-K 300 AANa 300 - - Example 7 KOH 2 ETGCA-Na 300 CMCNa 150 - - Example 8 KOH 2 BTGCA-Na 300 CMCNa 150 - - Example 9 KOH 2 HTGCA-TEA 300 CMCNa 150 - - Example 10 KOH 2 MDGCA-K 300 CMCNa 150 SS 1000 Example 11 KOH 2 MDGCA-K 300 CMCNa 150 CS 1000 Example 12 KOH 2 MDGCA-K 300 AANa 300 SS 1000 Comparative Example 1 KOH 2 - - CMCNa 150 - - Comparative Example 2 KOH 2 - - AANa 300 - - Comparative Example 3 KOH 2 - - CMCNa 150 SS 1000 Comparative Example 4 KOH 2 - - CMCNa 150 CS 1000 KOH: Potassium hydroxide
MDGCA: 2- (2-methoxyethoxy) acetic acid
MDGCA-K: Potassium 2- (2-methoxyethoxy) acetate
ETGCA-Na: sodium 2- (2- (2-ethoxyethoxy) ethoxy) acetate
BTGCA-Na: sodium 2- (2- (2-butoxyethoxy) ethoxy) acetate
HTGCA-TEA: tetraethylammonium 2- (2- (2- (hexyloxy) ethoxy) ethoxy) acetate
AANa: Sodium alginate
CMCNa: Carboxyl methyl cellulose sodium salt
SS: Sodium silicate
CS: colloidal silica

Experimental Example

Single crystal silicon wafers were respectively immersed in etching solution compositions for texturing of crystalline silicon wafers of Examples and Comparative Examples and etched. At this time, the texture condition was a temperature of 80 ° C and a time of 20 minutes.

One. Texture  Uniformity evaluation

(Example 3), Fig. 2 (Example 1), and Fig. 3 (Comparative Example 1). The results are shown in Table 2 and Fig. 1 (Example 3) Respectively.

◎: Formation of wafer front pyramid

?: Some of the wafers were not pyramid-formed (less than 5% of the pyramid structure was not formed)

DELTA: Some of the wafers were not pyramid-formed (the degree of pyramidal structure non-formation was 5% or more and less than 50%)

Х: Wafer pyramid not formed (pyramid not formed at least 50%)

2. Texture  Reflectance evaluation

The texture reflectance was measured by measuring the average reflectance when light having a wavelength band of 400 to 800 nm was irradiated using ultraviolet rays, and the results are shown in Table 2.

division Degree of pyramid formation Reflectance at 600 nm (%) Example 1 ○ 12.73 Example 2 ○ 13.21 Example 3 ◎ 12.14 Example 4 ◎ 11.31 Example 5 ◎ 10.84 Example 6 ◎ 11.04 Example 7 ◎ 11.12 Example 8 ◎ 10.98 Example 9 ◎ 11.32 Example 10 ◎ 11.07 Example 11 ◎ 12.21 Example 12 ◎ 11.47 Comparative Example 1 △ 16.51 Comparative Example 2 △ 17.74 Comparative Example 3 Х 19.62 Comparative Example 4 Х 19.76

Referring to Table 2, FIG. 1 and FIG. 2, it was confirmed that the etching solution composition for a texture of the silicon wafers of Examples 1 to 12 had a high-density pyramid formed on the entire surface thereof.

However, referring to FIG. 3, it can be confirmed that the compositions of Comparative Examples 1 to 4 are pyramidal in part of the wafer, or extremely over-etched in appearance.

Claims (9)

Alkaline compounds;
A compound of the formula 1 below; And
A texture etchant composition for crystalline silicon wafers comprising polysaccharides:
[Chemical Formula 1]

(Wherein R ₁ is, independently of each other, an alkyl group having 1 to 10 carbon atoms, a phenyl group or an allyl group,
R ₂ is a hydrogen atom or a methyl group,
n is an integer of 1 to 3,
M is ^{H, K +, Na +,} NH 4 +, N (CH 3) +, N (CH 2 CH 3) 4 +, N (C 2 H 4 CH 3) + or N (C ₃ H ₆ CH ₃ ) ⁺ ).
The method of claim 1, wherein the compound of Formula 1 is selected from the group consisting of 2- (2-methoxyethoxy) acetic acid, potassium 2- (2-methoxyethoxy) (2- (2-ethoxyethoxy) ethoxy) acetic acid, potassium 2- (2- (2-ethoxyethoxy) ethoxy) Ethoxy) acetate, sodium 2- (2- (2-butoxyethoxy) ethoxy) acetate and tetraethylammonium 2- (2- (2- (hexyloxy) ethoxy) ethoxy) acetate Wherein the etching solution is at least one selected from the group consisting of silicon nitride, silicon nitride, and silicon nitride.
[2] The composition of claim 1, wherein the compound of Formula 1 is contained in an amount of 10 ^-9 to 0.1% by weight based on the total weight of the etchant composition.
The composition according to claim 1, wherein the alkali compound is at least one selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, tetrahydroxymethylammonium, and tetrahydroxyethylammonium.
[3] The polysaccharide according to claim 1, wherein the polysaccharide is at least one selected from the group consisting of a glucan compound, a fructan compound, a mannan compound, a galactan compound, The texture etchant composition of the wafer.
The method of claim 1, further comprising: finely divided silica; A colloidal silica solution stabilized with Na ₂ O; A colloidal silica solution stabilized with K ₂ O; A colloidal silica solution stabilized with an acidic solution; A colloidal silica solution stabilized with NH ₃ ; A colloidal silica solution stabilized with at least one organic solvent selected from the group consisting of ethyl alcohol, propyl alcohol, ethylene glycol, methyl ethyl ketone and methyl isobutyl ketone; Liquid sodium silicate; Liquid potassium silicate; And at least one silica-containing compound selected from the group consisting of lithium silicate and liquid lithium silicate.
A method of etching a crystalline silicon wafer by an etching solution composition according to any one of claims 1 to 6.
8. The method of claim 7, wherein the etchant composition is sprayed onto a silicon wafer at a temperature of 50 to 100 DEG C for 30 seconds to 60 minutes.
8. The method of claim 7, wherein the silicon wafer is immersed in the etchant composition at a temperature of 50 to 100 DEG C for 30 seconds to 60 minutes.

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