Rapid environment-friendly double-sided polishing method for silicon wafer substrate

Abstract

The invention relates to the technical field of ultra-precision machining of semiconductors, in particular to a rapid environment-friendly double-sided polishing method for a silicon wafer substrate. The rapid environment-friendly double-sided polishing method for a silicon wafer substrate comprises the following steps: (1) rough polishing: carrying out chemical mechanical polishing on a silicon wafer substrate by using a rough polishing solution, wherein the rough polishing solution is prepared from cerium oxide, deionized water, a dispersing agent and a pH adjusting agent; (2) fine polishing: carrying out chemical mechanical polishing on the silicon wafer substrate subjected to rough polishing by using a fine polishing solution, wherein the fine polishing solution is prepared from cerium oxide, deionized water and a dispersing agent. According to the polishing method, a two-step chemical mechanical polishing method is adopted, cerium oxide polishing solutions with different particle sizes, different polishing pads and different pH conditions are adopted, the pressure of a polishing disc and the rotation speed ratio of a center gear are controlled, the polishing efficiency of the silicon wafer substrate can be effectively improved, the average thickness difference of the polished substrate is small, and the bending warping degree is low.

Description

technical field [0001] The invention relates to the technical field of ultra-precision processing of semiconductors, in particular to a fast, green and environment-friendly double-sided polishing method for a silicon wafer substrate. Background technique [0002] The substrate material is an important upstream product in the semiconductor industry. Its usual preparation method is to obtain crystal ingots through crystal growth. The crystal ingots are cut, ground, mechanically polished, chemically mechanically polished, cleaned, and packaged to obtain crystals that can be used for Out-of-the-box substrate wafers for epitaxy. The requirements of the epitaxial process for the substrate include no damage or scratch on the surface, low thickness difference, small bending and warpage, and good surface flatness. [0003] During the processing of the substrate material, the long-time grinding and polishing process will bring processing stress to the substrate sheet, making its surf...

AI Technical Summary

Problems solved by technology

However, the general chemical mechanical polishing process takes more than 4 hours. The chemical mechanical polishing method is divided into three steps, rough polishing, semi-finish polishing, and fine polishing. The lower material removal rate makes the time cost of the polishing process higher and greatly The increased stress in the substrate makes its surface shape very poor and it is difficult to meet the requirements of the epitaxial process

During the polishing process, it is necessary to add certain chemical reagents such as strong acid, strong alkali and strong oxide, which are dangerous and harmful to the operator and the operating environment, and special waste liquid treatment is required, which does not conform to the development concept of modern green and environmentally friendly processing.

Images