Silicon wafer and wet etching system

Abstract

The invention provides a silicon wafer, comprising a to-be-etched silicon wafer and a water film protecting layer compounded on the diffusion surface of the to-be-etched silicon wafer. The water film protecting layer formed on the diffusion surface of the to-be-etched silicon wafer is used for protecting the silicon wafer in the subsequent etching, so that chemical liquids cannot enter the diffusion surface of the silicon wafer in the subsequent wet etching process and excessive etching regions generated in the wet etching process can be removed; the effective light interception area of PN junctions can be increased and the photoelectric conversion efficiency can be improved. The invention further provides a wet etching system, comprising a water film spraying system arranged at the feeding end of wet etching equipment.

Description

technical field [0001] The invention relates to the technical field of wet etching in the solar cell manufacturing process, in particular to a silicon wafer and a wet etching system. Background technique [0002] A solar cell is a device that directly converts light energy into electrical energy through the photoelectric effect or photochemical effect. The most widely used solar cells are silicon solar cells. The manufacturing process of silicon solar cells is as follows: texturing, diffusion, etching, PEVCD, screen printing, sintering and testing. In the above-mentioned manufacturing process, since the edge of the battery after the silicon wafer is diffused, there will be N-type impurities and the P-type substrate to form a PN junction, and a thick phosphosilicate glass layer is formed on the surface of the battery during the diffusion process, so the silicon wafer needs to be The edges and surfaces are etched. [0003] RENA Inoxiside wet etching is the most common etchi...

AI Technical Summary

Problems solved by technology

The RENA Inoxiside chain wet etching machine uses a single-sided wet etching process, which makes the silicon wafer float on the chemical solution to etch side N-type silicon. However, the silicon wafer floats on the chemical solution. Liquid tension and immersion into the edge diffusion surface will inevitably affect the N-type silicon on the diffusion surface, which is an unavoidable defect in wet etching

[0004] At present, the RENA Ionxiside chain wet etching machine can control the width of the single-sided etching line at 0.5mm~1.0mm. The wider the etching line width, the larger the area of ​​the redundant etching area, and the effective light-receiving area of ​​the battery will decrease. Reduced, resulting in a decrease in open circuit voltage and short circuit current, and a decrease in cell efficiency

On the other hand, in the RENA Inoxiside chain wet etching machine, due to the bubble explosion in the reaction tank and the splashing of the etching solution, the dripping of the condensed etching solution above the tank, the unstable exhaust, and the abnormal flow rate, etc., caused The diffusion surface is damaged by the etching solution, which eventually leads to the appearance of various solar cells with poor appearance and electrical performance failure.

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