Method for cleaning surface of monocrystalline silicon wafer

Abstract

The invention relates to a method for cleaning the surface of a monocrystalline silicon wafer. The method is characterized by comprising the following steps: first of all, adding hydrogen peroxide (H2O2) and sodium hydroxide (NaOH) in a precleaning tank to obtain a mixed solution, in the mixed solution, the concentration of the hydrogen peroxide being 2% to 3%, and the concentration of NaOH being 0.15% to 0.3%; and cleaning the monocrystalline silicon wafer through cooperation with ultrasonic sound, the monocrystalline silicon wafer being immersed into the mixed solution during cleaning. Tests show that by adoption of the method provided by the invention, the texturing time is shortened, the output is increased, the smudginess on the surface of the silicon wafer such as oil stains, white spots, fingerprints and the like is completely cleaned, the quantity of reworking wafers is substantially reduced, silicon wafer discard proportion is reduced, and chemical use amount for reworking after texturing of the silicon wafer is correspondingly reduced.

Description

technical field [0001] The invention relates to a method for cleaning the surface of a single crystal silicon chip. Background technique [0002] After the monocrystalline silicon rod is cut into silicon wafers, the damaged layer and oil stains on the surface should be cleaned. Since the silicon wafer manufacturer does not clean it, the silicon wafer is held by hand during the silicon wafer inspection and packaging process, and the sweat and other organic matter stick to it. Attached to the surface of silicon wafers, there will be a lot of oil stains, white spots, finger prints and other dirty sheets during the production process of monocrystalline solar cells, which will eventually affect the appearance and conversion efficiency of the cells. [0003] At present, in the cleaning and texturing process, pure water and sodium hydroxide are added to the ultrasonic tank to pre-clean the surface of the silicon wafer. However, for silicon wafers with a dirty surface by physical me...

AI Technical Summary

Problems solved by technology

[0002] After the monocrystalline silicon rod is cut into silicon wafers, the damaged layer and oil stains on the surface should be cleaned. Since the silicon wafer manufacturer does not clean it, the silicon wafer is held by hand during the silicon wafer inspection and packaging process, and the sweat and other organic matter stick to it. Attached to the surface of silicon wafers, there will be a lot of oil stains, white spots, finger prints and other dirty sheets during the production process of monocrystalline solar cells, which will eventually affect the appearance and conversion efficiency of cells

[0003] At present, in the cleaning and texturing process, pure water and sodium hydroxide are added to the ultrasonic tank to pre-clean the surface of the silicon wafer. However, for silicon wafers with a dirty surface by physical metallurgy, this process cannot completely clean the oil on the surface of the silicon wafer. , white spots, fingerprints and other dirt, resulting in a long time for making texture, which can only be reworked or scrapped, resulting in the waste of a large number of silicon wafers and a large amount of chemicals, and the long cleaning time for texture seriously affects the output