Double-surface polishing method for silicon carbide chip

Abstract

The invention relates to a double-surface polishing method for a silicon carbide chip. The double-surface polishing method comprises the steps that the silicon carbide chip is subjected to rough polishing, semi-finishing polishing and finishing polishing sequentially on a double-surface polishing machine; during rough polishing, water-soluble diamond polishing liquid is used, the diameter of diamond particles is 5-15 microns, the polishing pressure is 40-100 kg, and a polishing disc is a resin copper disc or a resin tin disc or a polishing pad of a polyurethane structure; during semi-finishing polishing, water-soluble diamond polishing liquid is used, the diameter of diamond particles is 0.25-3 microns, the polishing pressure is 60-120 kg, and a polishing disc is a resin copper disc or a resin tin disc or a polishing pad of a polyurethane structure; and during finishing polishing, alkali silicon dioxide polishing liquid is used, an oxidizing agent with a proper proportion is added, the PH value of the finishing polishing liquid is adjusted to be 9-13, the polishing pressure is 80-140 kg, and a polishing pad is of a fluff structure. By means of the double-surface polishing method, the processing time can be shortened by a half, the flatness of the silicon carbide chip is improved, the surface quality is consistent after polishing, and the silicon carbide chip has no defects of orange peel, scratching damage, matte and the like.

Description

technical field [0001] The invention relates to the field of surface processing of silicon carbide (SiC) wafers, in particular to a double-sided polishing method for silicon carbide wafers. Background technique [0002] Silicon carbide (SiC) is an important third-generation semiconductor material. Compared with traditional semiconductor materials such as silicon (Si) and gallium arsenide (GaAs), it has high thermal conductivity, high breakdown field strength, and high saturation electron drift rate. Excellent properties such as high bonding energy and high bonding energy have great application prospects in high temperature, high frequency, high power and radiation resistant devices. [0003] With the successful use of silicon carbide single wafer polishing wafers in various fields, people began to pay more attention to the processing technology of silicon carbide single wafer. The hardness of silicon carbide crystal is relatively high, the Mohs hardness is about 9.3, which ...

AI Technical Summary

Problems solved by technology

The hardness of silicon carbide crystal is relatively high, the Mohs hardness is about 9.3, which is slightly lower than that of diamond, which makes its processing more difficult. At present, the mainstream processing technology in China is single-sided processing. Usually, one surface (such as carbon surface) is processed first, and then the other surface is processed. One side (such as the silicon side), the wafer obtained in this way not only has poor flatness, but also has a long processing cycle and high production costs. When processing the other side, it is easy to cause damage (scratch) caused by the secondary processing of the processed surface. Greatly restricts the development of silicon carbide wafer processing