Processing technology for reducing edge crystal holes of zone-melting POLY back-sealed single-side-polished wafer

Abstract

The invention provides a processing technology for reducing edge crystal holes of a zone-melting POLY back-sealed single-side-polished wafer. POLY back-sealing, thinning and polishing are carried outon an acid corrosion wafer in sequence, and optimal matching is carried out on a cleaning procedure after thinning. Because the thinning procedure is performed after the POLY back sealing procedure, the phenomenon of crystal holes generated in the POLY back sealing process can be greatly reduced. Compared with the prior art, the processing cost is not increased under the same processing steps, thepercent of pass of finished products is greatly increased, and the processing technology has very high practical application value.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a processing technology for reducing the crystal hole at the edge of a POLY back-sealing single throw sheet in a zone melting. Background technique [0002] As we all know, metal impurities and surface flatness are two important characteristic parameters of device raw material single crystal silicon polished wafers. On the one hand, the surface grinding technology applied to 12-inch polishing pads has greatly improved the surface flatness of the polishing pads. In recent years, this technology has gradually been applied to polished products smaller than 12 inches; The characteristics are widely used to reduce the metal impurities of the polishing sheet. When these two technologies are used to develop 8-inch zone melting and polishing products with high surface flatness requirements and low metal impurity content, due to the poor mechanical properties of zone m...

AI Technical Summary

Problems solved by technology

Although the lamination process reduces the edge crystal hole phenomenon of the Czochralski heavy-doped POLY back-sealed single-throw wafer, it cannot solve the edge crystal hole phenomenon of the 8-inch POLY back-sealed single-throw wafer. The reason is that the oxygen content ratio of the Czochralski wafer Melted silicon wafers are at least an order of magnitude higher, resulting in poorer mechanical properties of zone-fused silicon wafers than Czochralski silicon wafers, and it is easier to drop crystals and produce edge crystal holes after lamination processing

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