| 摘要 |
<p>PURPOSE:To restrain bird's beak, lattice defect, oozing of impurities, segregation, etc., by forming a phospho-silicate glass film or an arsenic glass film on an oxide mask, forming a polysilicon film from above the glass film, oxidizing the polysilicon film, selectively etching the phosopho-silicate glass film or the arsenic glass film, and performing field oxidation. CONSTITUTION:A pad oxide film 2, an oxide mask 3 of an Si3N4 film, and a phospho-silicate glass(PSG) film 6 are formed on a silicon substrate 1. An active region is patterned by etching using photo resist. A channel stopper 4 is formed by ion implantation, on the lower side of the pad oxide film 2 except the oxide mask 3 and the lower side of the phospho-silicate glass film 6. A polysilicon film 7 is formed, and oxidation is performed. The oxide film 3 of Si3N4 is exposed by selectively etching and eliminating a PSG region 200. A polysilicon film 7b and the upper part of the silicon substrate 1 are oxidized by field oxidation, and a final field oxide film 8 is formed.</p> |
