Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To realize the burial of both flat members by increasing the ratio of etching selection of doped poly Si to non-doped poly Si by formation of an oxide film in the upper part of the poly Si. CONSTITUTION:An N<+> buried layer 12 and an N type epitaxial region 13 are formed on an Si semiconductor substrate 11, further a thermal oxide film 14 is formed, thus an Si3N4 film being deposited. A PSG film 16 is deposited thereon and dry-etched, resulting in formation of a groove 17, which is then provided with a channel stopper region 18 by boron implantation. Next, the oxide film 19 is formed by oxidation of the bottom and side surface of the groove, and thereafter the poly Si is deposited. Phosphorus is diffused from the film 16 to the poly Si above on heat treatment, thus the poly Si in the part other than the groove 17 being changed into the N<+> doped poly Si 20. The phosphorus-doped poly Si 21 is removed, and the goove is filled with the poly Si 20.

Inventors

• 👤 Haruhide Fuse
• 👤 玄秀 布施
• 👤 Hideaki Shimoda
• 👤 秀明 下田
• 👤 Kazuya Kikuchi
• 👤 菊池　和也
• 👤 Tadanaka Yoneda
• 👤 米田　忠央

Bibliographic Details