Surface damage layer cleaning process for crystal silicon RIE texturing

Abstract

The invention relates to a surface damage layer cleaning process for crystal silicon reactive ion etching (RIE) texturing, which comprises the following steps of: performing deionized water surface pre-cleaning on the damage layer on the surface of a silicon chip; performing first damage removal cleaning by using mixed solution of HF, HNO3 and water or acetic acid in a ratio of 1:50:100; cleaningthe damage layer by using deionized water; performing secondary cleaning and etching at the temperature of between 60 and 75 DEG C by adopting mixed solution of HN4OH, H2O2 and H2O in a ratio of 1:1:5, wherein the secondary cleaning time is controlled in a range of 5 to 15 minutes; washing the damage layer by using 0.5 percent hydrogen fluoride (HF) solution after the secondary cleaning and etching are completed; and finally, cleaning the damage layer by using the deionized water. The process is suitable for a damage removal process of a fine surface structure of the crystal silicon RIE texturing, and better ensures that the etching process does not affect the fine velvet structure on the surface of the silicon chip.

Description

technical field

[0001] The invention relates to a production process of a crystalline silicon solar cell, in particular to a process for cleaning a damaged surface layer of crystalline silicon RIE texturing. Background technique

[0002] At present, strong alkaline chemicals (NaOH, KOH, etc.) or strong acidic chemicals (HF+HNO) are generally used in the industrial production of crystalline silicon solar cells. 3 ) aqueous solution to clean the damaged layer on the surface of the silicon wafer. It is generally used in the surface treatment process in the preparation of the suede on the surface of the battery. The purpose is to eliminate the cutting damage layer on the surface of the silicon wafer. The thinning of the silicon wafer is generally 5-15 μm.

[0003] In the preparation process of crystalline silicon surface suede by RIE (reactive ion etching), a certain surface damage layer will be introduced, but the thickness of the damage layer on this surface is 0.1-0.4 μm, an...