Corrosion technology of high-reflectivity acid corrosion wafer

Abstract

The invention relates to a corrosion technology of a high-reflectivity acid corrosion wafer. The method is to discharge a certain amount of mixed acid liquor from an etching bath or add a certain amount of mixed acid liquor for the acid etching bath according to the processing amount of acid corrosion wafers in the corrosion processing process and adopt the overflow circulation mode to control the concentration of the mixed acid liquor in the acid etching device, wherein the overflow circulating amount of the mixed acid is 400-700L / min. The specific control method comprises the following steps: using the mixed acid liquor for corrosion processing, discharging 150-250L of the mixed acid liquor after continuously processing 500-800 silicon wafers with the fresh mixed acid liquor, and then adding 150-250L of the mixed acid liquor. The quality parameters of the high-reflectivity acid corrosion wafer prepared by the technology of the invention are stable; and the invention also find a control method for adding or discharging the mixed acid liquor and the method is suitable for batch production, thus reducing the replacement frequency of the mixed acid liquor, lowering the cost and increasing the production efficiency.

Description

technical field [0001] The invention relates to an acid etching process for a single crystal silicon wafer, in particular to an etching process for an acid corrosion wafer with a high reflectivity. Background technique [0002] There are many chemical etching reagents for silicon single wafers, including acids, alkalis and various salts, etc., but due to the limitations of the two factors of high-purity reagents and metal ion contamination, HNO is now widely used 3 -HF etchant and alkaline etchant. The process of alkali etching silicon wafer is simple and easy to operate. At present, there are many processes of alkali etching in China. The alkali etching process is anisotropic corrosion, the corrosion rate is slow, and the surface roughness is relatively large. Due to the purity of the reagents and other reasons, there are more metal ions on the surface and the surface recombination effect is greater. Therefore, most manufacturers currently prefer to use acid etching. sili...

AI Technical Summary

Problems solved by technology

This method is developed on the basis of the original acid etching process of silicon wafers, and the key is to solve the problem of how to ensure that the glossiness of high reflectivity acid corrosion wafers meets the technical indicators