Method for washing silicon wafer by organic solvent

Abstract

The invention discloses a method for washing a silicon wafer by an organic solvent, and relates to a silicon wafer washing technology. The method, in sequence, comprises the following steps: (a) after taking the silicon wafer from a mortar liquid; immediately putting the silicon wafer into hot water at 50-100 DEG C; and ultrasonically washing the silicon wafer for 10-30 minutes; and (b) putting the silicon wafer into an organic washing liquid YB and ultrasonically washing the silicon wafer for more than 30 minutes at 30-75 DEG C, wherein the organic washing liquid YB is an aqueous solution with organic ethanol and acetone as a solute; and the frequency of ultrasonic waves is 28-40 kHz; and the power is 2500-3000 W. The method for washing the silicon wafer by the organic solvent, disclosed by the invention, has the advantages as follows: smudges on the surface of the silicon wafer can be easily washed and the original mechanical damage layer of the silicon wafer is kept. It is shown by detection that the reflectivity of the silicon wafer is further reduced by about 2% in the later section of the texture acid-etching process. The washing efficiency is increased without introducing impurity ions; and washing cost and pollution are reduced.

Description

technical field [0001] The invention relates to the technical field of manufacturing solar-grade silicon wafers, in particular to the silicon wafer cleaning technology. Background technique [0002] Since the solar grade silicon wafer is made into a solar cell texturing section, the acid texturing process mainly relies on the crystal defects of the silicon wafer and the damaged layer on the surface of the silicon wafer. Therefore, the surface of the silicon wafer must be dirty when cleaning the silicon wafer. Clean it up, and do not damage the damaged layer on the surface of the silicon wafer. [0003] The current cleaning method for silicon wafers is: acid washing or alkali washing and silicon wafer cleaning methods. Whether it is an acidic solution or an alkaline solution, it will definitely destroy the mechanical damage layer left in the silicon wafer manufacturing process, but in the acid texturing process in the later stage, the acid solution mainly relies on the cryst...

AI Technical Summary

Problems solved by technology

Whether it is an acidic solution or an alkaline solution, it will definitely destroy the mechanical damage layer left in the silicon wafer manufacturing process, but in the acid texturing process in the later stage, the acid solution mainly relies on the crystal defects and mechanical damage layer of the silicon wafer to complete the process. Texture-making, so acidic or alkaline inorganic cleaning solution can not guarantee the effect of velvet-making