Water film protection wet etching process for diffusing surface

Abstract

The invention relates to a chained wet etching process during manufacturing of solar batteries, in particular to a water film protection wet etching process for a diffusing surface. The process comprises the following steps of: firstly, forming a water film protection layer on the diffusing surface of a silicon slice to be etched, wherein the water film protection layer is used for protecting the diffusing surface of the silicon slice during subsequent etching; and performing the conventional wet etching on the silicon slice floating on an etching liquid medicine. In the process, the water film protection layer is formed on the surface of the silicon slice by using surface tension of the liquid, so residual etching regions produced in the conventional wet etching process can be removed, effective light-receiving areas of a P node and an N node are increased and the photoelectric conversion efficiency can be improved; furthermore, the damage of the etching liquid medicine to the diffusing surface, which is caused by the problems of the splashing of the etching liquid medicine due to the rupture of bubbles in an etching slot, the drippage of etching liquid medicine drops coagulated above a slot body, unstable air exhaust, abnormal flow rate and the like, can be eliminated, so that the production proportion of various appearance unqualified slices to electric performance ineffective slices of the solar battery can be finally reduced.

Description

technical field [0001] The invention relates to a wet etching process in the solar cell manufacturing process, in particular to a wet etching process for water film protection on a diffusion surface. Background technique [0002] The RENA Inoxiside chain wet etching machine uses a single-side wet etching process, which makes the silicon wafer float on the chemical solution to etch the N-type silicon on the side. However, the silicon wafer floats on the chemical solution and is immersed into the edge diffusion surface due to the liquid tension, which will inevitably affect the N-type silicon on the diffusion surface, which is an unavoidable defect of wet etching. Such as figure 1 and 3 As shown, the current RENA Inoxiside chain wet etching machine can control the width of the single-side etching line at a level of 1.0 mm to 2.0 mm. The wider the etching line width, the larger the area of ​​the redundant etching area 9, and the effective efficiency of the battery. The light...

AI Technical Summary

Problems solved by technology

However, the silicon wafer floats on the chemical liquid, and due to the liquid tension, it is immersed into the edge diffusion surface, which will inevitably affect the N-type silicon on the diffusion surface. This is an unavoidable defect of wet etching.

like figure 1 and 3 As shown, the current RENA Inoxiside chain wet etching machine can control the width of the single-side etching line at a level of 1.0 mm to 2.0 mm. The wider the etching line width, the larger the area of ​​the redundant etching area 9, and the effective efficiency of the battery. The light-receiving area will be reduced, resulting in a decrease in short-circuit current and a decrease in the efficiency of the cell

[0003] At the same time, the RENA Inoxiside chain wet etching machine is often caused by problems such as bubble bursting in the reaction tank, splashing of etching liquid, condensation of etching liquid drops on the top of the tank, unstable exhaust, abnormal flow, etc. Destroyed by the etching solution, it will eventually lead to the production of various solar cells with poor appearance and electrical performance failure.

Images