Texturing liquid for crystalline silicon and preparation method thereof

A technology for making texturing liquid and crystal silicon, which is applied in chemical instruments and methods, crystal growth, single crystal growth, etc. It can solve the problems that the surface of the silicon wafer cannot obtain contact with it, the concentration of the reactant -OH is reduced, and the production cost cannot be reduced, etc. problems, to achieve the effects of reducing environmental pollution and waste water treatment costs, stabilizing the solution system, and broadening the process tolerance range

Inactive Publication Date: 2018-03-30
TONGWEI SOLAR (ANHUI) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] During the silicon wafer texturing production process, solution failure is the main reason for the fluctuation of the production process. The reason for the failure lies in the continuous consumption of NaOH and the continuous production of Na2SiO3 during the reaction process, which leads to a decrease in the concentration of the reactant -OH, and the surface of the silicon wafer cannot communicate with it. Obtain sufficient contact rate; and because the reaction is carried out at a high temperature of about 80-90 degrees, a violent reaction often occurs and a large number of bubbles are generated, and the resulting suede is not ideal
[0013] But the existing traditional technology generally suppresses the progress of the reaction by adding sodium silicate and IPA (isopropanol), controls the reaction rate, thereby obtains a relatively good suede state, and the publication number is CN 104282796B "a kind of silicon crystal Texturing solution and its preparation method", which uses a large amount of isopropanol and absolute ethanol to inhibit the reaction, thereby making the texture better, but the use of a large amount of isopropanol and absolute ethanol will cause environmental pollution and high cost waste water treatment costs, unable to reduce production costs

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Add deionized water into the reaction kettle, according to the mass percentage, dissolve 30% sodium hydroxide in deionized water, then add 0.2% isopropanol and 0.4% absolute ethanol in turn, and then pour the mixed solution into the storage tank and add 5% liquid carbon dioxide and 2% alkali catalyst at the same time, then pressurize the storage tank, and finally add 5% sodium hypochlorite and 3% sodium citrate, fructose sodium and lignosulfonate to 1 : 1:3 non-ionic surfactant composed of 3 parts by mass to obtain the texturing liquid.

[0035] Use this texturing liquid to make texture on crystal silicon, keep the texture temperature at 80°C, and the texture time is 30 minutes. After the texture is completed, the thickness of crystal silicon is reduced by 6.3 microns, the corrosion effect is better, the reflectivity is reduced, and the corrosion The pits are more uniform.

Embodiment 2

[0037] Add deionized water into the reaction kettle, according to the mass percentage, dissolve 50% sodium hydroxide in deionized water, then add 0.5% isopropanol and 0.8% absolute ethanol in turn, then pour the mixed solution into the storage tank In, and add 10% liquid carbon dioxide and 5% alkali catalyst simultaneously, carry out pressurized filtration to storage tank then, finally add 10% sodium hypochlorite and 8% sodium citrate, fructose sodium and lignosulfonate to 1 : 1:3 non-ionic surfactant composed of 3 parts by mass to obtain the texturing liquid.

[0038] Use this texturing liquid to make texture on crystal silicon, keep the texture temperature at 80°C, and the texture time is 30 minutes. After the texture is completed, the thickness of crystal silicon is reduced by 6.7 microns, the corrosion effect is better, the reflectivity is reduced, and the corrosion The pits are more uniform.

Embodiment 3

[0040] Add deionized water into the reaction kettle, according to the mass percentage, dissolve 40% sodium hydroxide in deionized water, then add 0.3% isopropanol and 0.6% absolute ethanol in turn, then pour the mixed solution into the storage tank and add 8% liquid carbon dioxide and 3% alkali catalyst at the same time, then pressurize the storage tank, and finally add 7% sodium hypochlorite and 5% sodium citrate, sodium fructose and lignosulfonate to 1 : 1:3 non-ionic surfactant composed of 3 parts by mass to obtain the texturing liquid.

[0041] Use this texturing liquid to make texture on crystal silicon, keep the texture temperature at 80°C, and the texture time is 30 minutes. After the texture is completed, the thickness of crystal silicon is reduced by 6.5 microns, the corrosion effect is better, the reflectivity is reduced, and the corrosion The pits are more uniform.

[0042] The reaction principle of crystalline silicon texturing is shown in the equation: Si+2NaOH+H...

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PUM

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Abstract

The invention discloses a texturing liquid for crystalline silicon. The texturing liquid comprises the following components in percentages by mass: 30% to 50% of sodium hydroxide, 0.2% to 0.5% of isopropanol, 0.4% to 0.8% of absolute ethyl alcohol, 5% to 10% of liquid carbon dioxide, 5% to 10% of sodium hypochlorite, 2% to 5% of a basic catalyst and 3% to 8% of a nonionic surfactant, with the balance being deionized water. The invention also discloses a preparation method of the texturing liquid for the crystalline silicon. The preparation method comprises the following steps: 1) adding the deionized water into a reaction vessel, then dissolving the sodium hydroxide in the deionized water, and successively adding the isopropanol and the absolute ethyl alcohol; 2) adding the liquid carbon dioxide and the basic catalyst; and 3) adding the sodium hypochlorite and the nonionic surfactant so as to obtain the texturing liquid. The preparation method provided by the invention can effectivelyreduce the usage amount of conventional organic solvents, i.e., the isopropanol and the absolute ethyl alcohol, greatly reduces pollution to the operating environment due to solvent volatilization andthe cost of wastewater treatment, and reduces COD and production cost.

Description

technical field [0001] The invention relates to the technical field of semiconductor texturing, in particular to a crystal silicon texturing liquid and a preparation method thereof. Background technique [0002] In the information age, with the continuous consumption of energy, the importance of renewable energy will become more and more prominent, such as solar energy, wind energy, tidal energy and other renewable energy. Energy, its rapid development is unprecedented, and my country, as the world's largest photovoltaic industry, is advancing towards a strong country, but its supporting electronic chemicals industry is relatively backward, which seriously restricts the advantageous development of the industrial chain. [0003] Solar cells, also known as photovoltaic cells, are semiconductor devices that directly convert solar light energy into electrical energy. Because they are green and environmentally friendly products, they will not cause environmental pollution, and the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/06C30B33/10H01L31/18
CPCC30B29/06C30B33/10H01L31/1804Y02P70/50
Inventor 林宝剑谢毅唐亮程寅亮关振华
Owner TONGWEI SOLAR (ANHUI) CO LTD
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