Unlock instant, AI-driven research and patent intelligence for your innovation.

Wet etching method for silicon chip and method for producing solar cell

A technology of wet etching and silicon wafers, which is applied in the field of solar photovoltaic utilization, can solve the problems of poor uniformity of front edge corrosion of silicon wafers, easy corrosion of the front surface of silicon wafers, and affecting the qualified rate of finished products, so as to improve appearance and good edge insulation , the effect of high pass rate

Active Publication Date: 2012-07-11
YINGLI ENERGY CHINA
View PDF3 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the hydrophilicity of phosphosilicate or borosilicate glass, after removing the glass on the front surface of the silicon wafer with wet etching chemical liquid, it is easy to corrode the front surface of the silicon wafer, especially the position about 1mm away from the edge of the silicon wafer, resulting in The corrosion uniformity of the front edge is relatively poor, which not only affects the appearance but also causes the battery to leak to a certain extent, affecting the qualified rate of its finished products

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Wet etching method for silicon chip and method for producing solar cell
  • Wet etching method for silicon chip and method for producing solar cell
  • Wet etching method for silicon chip and method for producing solar cell

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] After the qualified polycrystalline P-type silicon wafer is subjected to surface texturing and diffusion bonding treatment, the polycrystalline P-type silicon wafer is rinsed with 10% hydrofluoric acid, and the rinse time is controlled to 1 min. After rinsing with water for 2 minutes, the silicon wafer is dried, and then the dried silicon wafer is etched with a mixture of hydrofluoric acid, nitric acid and sulfuric acid. The concentration of hydrofluoric acid in the mixture is 15g / L, and the concentration of nitric acid is 300g / L, the concentration of sulfuric acid is 320g / L, control the etching depth of the side and back of the silicon wafer to 1.5±0.2μm, and the insulation resistance is greater than 1KΩ. After measurement, the corrosion edge of the front surface of wet etching is less than 0.5mm.

[0046] An anti-reflection film is fabricated on the surface of the wet-etched silicon wafer, and then the front electrode and the back electrode are fabricated and sintered to...

Embodiment 2

[0051] After the qualified single crystal P-type silicon wafer is subjected to surface texturing and diffusion bonding treatment, the single-crystal P-type silicon wafer is rinsed with 5% hydrofluoric acid, and the rinse time is controlled to 5 minutes. After rinsing with ionized water for 3 minutes, the silicon wafers were dried, and then the dried silicon wafers were etched with a mixture of hydrofluoric acid and nitric acid. The concentration of hydrofluoric acid in the mixture was 20g / L and the concentration of nitric acid was 300g. / L, the concentration of sulfuric acid is 350g / L, the etching depth of the side and back of the silicon wafer is controlled to be 1.5±0.2μm, and the insulation resistance is greater than 1KΩ. After measurement, the corrosion edge of the front surface of wet etching is less than 0.5mm.

[0052] An anti-reflection film is fabricated on the surface of the wet-etched silicon wafer, and then the front electrode and the back electrode are fabricated and...

Embodiment 3

[0057] After the good polycrystalline P-type silicon wafer is processed by conventional methods for surface texturing and diffusion bonding, the polycrystalline P-type silicon wafer is rinsed with hydrofluoric acid at a concentration of 5%, and the rinse time is controlled to 5 minutes. Rinse the silicon wafers with deionized water for 3 minutes, and then etch the dried silicon wafers with a mixture of hydrofluoric acid and nitric acid. The concentration of hydrofluoric acid in the mixture is 17g / L, and the concentration of nitric acid It is 330g / L, the concentration of sulfuric acid is 350g / L, the etching depth of the side and back of the silicon wafer is controlled to be 1.5±0.2μm, and the insulation resistance is greater than 1KΩ. After measurement, the corrosion edge of the front surface of wet etching is less than 0.5mm.

[0058] An anti-reflection film is fabricated on the surface of the wet-etched silicon wafer, and then the front electrode and the back electrode are fabri...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Resistanceaaaaaaaaaa
Login to View More

Abstract

The invention provides a wet etching method for a silicon chip. The method comprises the following steps of: rinsing each surface of the silicon chip obtained by dispersed junction making by using hydrofluoric acid; flushing each surface of the silicon chip by using deionized water; drying the surfaces of the silicon chip; and etching the lateral surfaces and the back of the silicon chip by using a mixed solution of hydrofluoric acid, nitric acid and sulfuric acid. The invention also provides a method for producing a solar cell. The method for producing the solar cell sequentially comprises silicon chip detection, surface texture making treatment, dispersed junction making treatment, and wet etching treatment, antireflective film plating treatment, making of a front electrode and a rear electrode and sintering treatment involved in the above technical scheme. By the wet etching method for the silicon chip, corrosion to the front surface of the silicon chip is reduced, the front surface is protected, the appearance of the front surface of the silicon chip is improved, and the edge is well insulated. The unqualified percentage of the reverse current of the solar cell prepared by adopting the wet etching method is less than 0.2 percent, electric leakage of the solar cell is reduced, and the qualification rate of the solar cell is high.

Description

Technical field [0001] The invention relates to the field of solar photovoltaic utilization, in particular to a wet etching method for silicon wafers and a solar cell production method. Background technique [0002] Solar energy is an inexhaustible renewable energy source for human beings. It is also a clean energy source and does not cause any environmental pollution. Among the effective utilization of solar energy, the utilization of solar energy is the fastest growing and most dynamic research field in recent years, and it is one of the most eye-catching projects. For this reason, people have researched and developed solar cells. Solar cells are devices that directly convert light energy into electrical energy through photoelectric effect or photochemical effect. At this stage, the mainstream of thin-film solar cells that work with radio and television effects is that the sun shines on the semiconductor PN junction to form new hole-electron pairs. Under the action of the PN ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C30B33/10C23F1/24H01L21/02H01L21/306H01L31/18
CPCY02P70/50
Inventor 李高非徐卓郎芳崔景光
Owner YINGLI ENERGY CHINA