Polishing process of 8-inch polished wafers doped with silicon lightly

Abstract

The invention relates to a polishing process of 8-inch polished wafers doped with silicon lightly. In the process, a waxed single-surface polishing system is adopted, and two-time rough polishing, one-time medium polishing and one-time finish polishing are comprised. Each time of polishing is carried out in four stages. The polishing pressure of each stage of rough polishing is set in a range of 1.5 -2.2 bar. The total polishing time of the four stages of the rough polishing is set in a range of 8-11 min. The polishing pressure of each stage of medium polishing is set in a range of 1.2 -2.0 bar. The total polishing time of the four stages of the medium polishing is set in a range of 7-10 min. The polishing pressure of each stage of finish polishing is set in a range of 0.5 -1 bar. The total polishing time of the four stages of the finish polishing is set in a range of 7-10 min. According to the process, the surface geometric parameters and other quality indexes of the polished wafers doped with silicon lightly are improved, and all of the indexes reach and exceed industrial standards, therefore, the technical problem that traditional process is not suitable for polishing 8-inch polished wafers doped with silicon lightly is solved.

Description

technical field [0001] The invention relates to a silicon chip manufacturing process for semiconductor power devices, in particular to a polishing process for an 8-inch lightly doped silicon polishing chip. Background technique [0002] Wafer polishing is the use of chemical and mechanical action to finally eliminate the damage and deformation layer on the surface of the silicon wafer. Chemical mechanical polishing combines the characteristics of chemical polishing without damage and mechanical polishing to obtain a smooth and bright surface. During the polishing process, the two effects of chemical corrosion and mechanical friction are carried out alternately and cyclically in this way, so as to remove the mechanical damage left on the surface of the silicon wafer due to the previous process, so as to obtain a smooth, bright, damage-free mirror surface with high geometric precision. [0003] Alkaline silica polishing technology adopts chemical polishing and mechanical poli...

AI Technical Summary

Problems solved by technology

This has brought greater difficulty to the development of 8-inch lightly doped silicon polishing wafers

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