A kind of fast green environmental protection double-sided polishing method of silicon wafer substrate

Abstract

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. A method for quickly green and environmentally friendly double-sided polishing of a silicon wafer substrate comprises the following steps: (1) rough polishing: the silicon wafer substrate is chemically mechanically polished with a rough polishing solution; the rough polishing solution is composed of cerium oxide, Ionized water, dispersant and pH adjustment agent are prepared; (2) fine polishing: the silicon wafer substrate is carried out chemical mechanical polishing with fine polishing liquid after rough polishing; The fine polishing liquid is made of cerium oxide, deionized water and Dispersants are prepared. The polishing method of the present invention adopts a two-step chemical mechanical polishing method. By adopting cerium oxide polishing fluids of different particle sizes, different polishing pads and different pH conditions, and controlling the pressure of the polishing disc and the rotational speed ratio of the central gear, the silicon wafer can be effectively improved. The polishing efficiency of the substrate is high, and the average thickness difference of the polished substrate is small, and the bending and warpage are 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.

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