Monocrystalline silicon wafer precleaning liquid and cleaning method thereof

Abstract

The invention relates to monocrystalline silicon wafer precleaning liquid and a cleaning method thereof. The invention is characterized in that the precleaning liquid comprises the following compositions: hydrogen peroxide, sodium hydroxide or potassium hydroxide, and water. The cleaning method of the monocrystalline silicon wafer precleaning liquid as in claim 1 is characterized in that the method comprises the following steps: putting a silicon wafer inserted into a flower basket into a uniformly mixed monocrystalline silicon wafer precleaning liquid at a temperature of 55-80 DEG C, performing ultrasonic cleaning for 60-600 seconds, after ultrasonic cleaning, rinsing with deionized water at 60 DEG C for 1 min, after deionized water rinsing, taking the silicon wafer out, and drying. The advantages of the invention are that with the hydrogen peroxide process, the alkali concentration is reduced; the hydrogen generation amount is low; no bubble trace is generated on the silicon wafer surface; no basket rinsing is caused; no obvious boundary is generated. Since the alkali concentration is reduced, the thickness reduction amount is effectively decreased, which facilitates the reduction of the fragment rate of battery pieces in subsequent procedures.

Description

technical field [0001] The invention relates to a single crystal silicon chip pre-cleaning solution and a cleaning method thereof. Background technique [0002] Solar cells use the interaction of sunlight and materials to directly generate electricity, without consuming fuel and water, and do not release any gas including carbon dioxide during use. It is a renewable energy source that does not pollute the environment. It is of great significance to improve the ecological environment and alleviate the harmful effects of greenhouse gases. Therefore, solar cells are expected to become an important new energy source in the 21st century. [0003] The cell manufacturing process is mainly pre-cleaning→texturing→diffusion→etching→phosphorous silicon glass→coating with anti-reflection film→printing→sintering→testing. [0004] After the solar silicon wafer is cut by wire cutting machine, its surface has been seriously polluted. To meet the industrial application standard of solar po...

AI Technical Summary

Problems solved by technology

During the slicing process, a damaged layer will be generated on the surface of the silicon wafer. Insufficient removal of the damaged layer will lead to residual defects, residual defects will continue to extend to the depth of the material during the subsequent high-temperature treatment, and impurities caused during the cutting process will not be completely removed. These Both will increase the surface recombination rate of the silicon wafer, seriously affecting the efficiency of the cell

[0006] At present, the damage-removing process is generally used for cleaning. Since the conventional process used in the initial polishing process is a low-concentration alkali (about 1%), the reaction process is relatively violent, and hydrogen bubbles are generated during the reaction process. Since the bubbles cannot be separated from the surface of the silicon wafer in time, the entire surface is damaged. The silicon wafers in the basket floated, so that some of the silicon wafers were not soaked in the reaction solution and could not continue to react, and there were obvious boundaries in the appearance of the silicon wafers