A method for reworking silicon wafer coated color difference film

Abstract

The invention discloses a reworking method of silicon wafer coating film color shading slices. The reworking method comprises the steps of wet etching, washing, drying, tubular PECVD coating and printing and sintering. The process of the wet etching is that the color shading slices are subjected to surface etching through HF solutions with mass concentration of 8-15% to eliminate silicon nitride on the surface of silicon wafers; the tubular PECVD coating comprises twice coating, the first coating time is 100-160 s, the throughput of SiH4 is 1000-1300 mL / min, and the throughput of NH3 is 4700-5700 mL / min; the second coating time is 600-680 s, the throughput of the SiH4 is 600-770 mL / min, and the throughput of the NH3 is 6800-7500 mL / min. The film washing process is optimized, the velvet making and diffusion steps can be omitted, damage to the silicon wafers and the silicon wafer breaking rate are reduced, raw material consumption is reduced, production cost is reduced, and work efficiency is improved.

Description

technical field [0001] The invention relates to a method for reworking a color-difference film coated on a silicon wafer. Background technique [0002] Solar cells mainly convert sunlight into electrical energy, which is a kind of green energy in real life. Solar cells are formed by cleaning the surface of the original silicon wafer, making texture, diffusing to form a PN junction, removing phosphosilicate glass, depositing silicon nitride, printing, and sintering. Cleaning the surface of the silicon wafer is mainly the first step in the battery production process. It mainly uses the damaged layer formed during the cutting of the silicon wafer to corrode the surface of the silicon wafer through chemical liquid, thereby forming an uneven surface on the surface of the silicon wafer. And a large number of holes, thereby reducing the reflectivity of the silicon wafer surface and improving the conversion efficiency of the battery. [0003] Because most of the deposition of sili...

AI Technical Summary

Problems solved by technology

Chromatic aberration films need to go through high-concentration pickling to remove the silicon nitride and PN junction on the surface of the silicon wafer. The thickness of the removed silicon wafer is about 5 μm, and the texture is re-textured. The depth of the texture is 2-4 μm, and the diffusion process is 800 ° Reacting at the above temperature will cause damage to the silicon wafer, thereby increasing the fragmentation rate of the silicon wafer, increasing consumption, and increasing production costs.