A kind of single crystal silicon chip pre-cleaning liquid and cleaning method thereof

Abstract

The invention relates to a single crystal silicon chip pre-cleaning solution and a cleaning method thereof. It is characterized in that it consists of the following components: the pre-cleaning liquid is composed of hydrogen peroxide, sodium hydroxide or potassium hydroxide and water. It is characterized in that it consists of the following components: hydrogen peroxide, sodium hydroxide or potassium hydroxide, and water. A cleaning method using a single crystal silicon wafer pre-cleaning solution according to claim 1, characterized in that: putting the silicon wafer inserted into the flower basket into the uniformly mixed single crystal silicon wafer pre-cleaning solution at a temperature of 55 At ~80°C, use ultrasonic cleaning for 60-600 seconds. After ultrasonic cleaning, rinse with deionized water for 1 minute at 60°C. After rinsing with deionized water, take out the silicon wafer and dry it. The invention has the advantages that after using the hydrogen peroxide process, the concentration of alkali is reduced, the amount of hydrogen generated is small, and no bubble marks will be produced on the surface of the silicon wafer, and there will be no drifting and no obvious boundaries. Since the concentration of the alkali is reduced, the amount of thinning is also effectively reduced, which is beneficial to reduce the fragmentation rate of the battery sheet in the subsequent process.

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