Method for processing diffused high-sheet-resistance silicon wafer

Abstract

The invention provides a processing method for a diffused high-sheet-resistance silicon wafer, and the method comprises the following steps: S1, enabling the diffused high-sheet-resistance silicon wafer to be placed in a mixed solution of H2SO4 / HNO3 / HF for secondary etching, and enabling the etching depth to be (1.0-1.2) [mu]m; S2, cleaning the etched silicon wafer with the high sheet resistance by using DI pure water; S3, removing the porous silicon structure on the surface of the high-sheet-resistance silicon wafer by using a KOH solution; S4, performing DI pure water cleaning; S5, removingthe oxide layer on the surface of the high-sheet-resistance silicon wafer by using an HF solution; S6, performing DI pure water cleaning; S7, performing drying in a drying tank; S8, transferring the dried high-sheet-resistance silicon wafer into the diffusion process again for secondary diffusion, wherein the secondary diffusion temperature is 10-30 DEG C lower than the conventional diffusion process temperature; S9, carrying out secondary etching on the high-sheet-resistance silicon wafer after secondary diffusion to improve the back polishing effect, and then transferring to a normal production process.

Description

technical field [0001] The invention relates to the technical field of photovoltaic cell production, in particular to a method for processing a diffused high-resistance silicon wafer. Background technique [0002] As a green and environmentally friendly new energy source, solar cells have attracted worldwide attention. The global photovoltaic industry is developing very rapidly, and the domestic photovoltaic industry continues to grow. [0003] With the continuous development of the industry, customers have higher and higher requirements on the performance and appearance of solar cells, and low-wattage modules and flower modules have been eliminated by the market. Only by continuously reducing production costs can enterprises survive in the market. Improving conversion efficiency is one of the most effective ways to reduce production costs. [0004] The texturing process is the most important step in the battery production process. Its purpose is to use the mixed solution...

AI Technical Summary

Problems solved by technology

[0005] After the texturing process is the diffusion process. In the process of diffusion production, the process is terminated due to abnormal equipment or flash off of peripheral equipment, resulting in frequent occurrence of unqualified surfaces with high diffusion resistance. Oxide, no direct secondary diffusion

The traditional processing method is to return to the first process of texturing. The direct result of this method is that the silicon wafer becomes thinner and the production cost increases. The chip fragmentation rate is much higher, and the surface chip of the unqualified silicon chip with high square resistance undergoes secondary texturing to produce bright cells, resulting in a decrease in short-circuit current and short-circuit voltage, and a decrease in conversion efficiency, thereby increasing production costs

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