Semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To prevent the occurrence of crystal defects and strain induced by the selective oxidation by the mask of a nitride film at the same time, by combining the etching of a silicon groove and the formation of a silicon oxide film by gaseous phase growing, thereby making the thickness of the oxide film uniform in the vicinity of an active region. CONSTITUTION:A silicon nitride film 102 is formed on the surface of a semiconductor substrate 101 by thermal oxidation. A silicon nitride film 103 is formed thereon by a gaseous phase growing. Then a hole, which reaches the surface of the substrate, in double-layer films. A groove 104 is formed through the hole by anisotropic dry etcing at the same time. The inner surface of the groove is etched by isotropic wet etching. The inner surface of the groove is thermally oxidized, and a silicon oxide film 105 is formed. The groove is buried by a polycrystalline silicon 18. A silicon oxide film 106 on the silicon nitride film 103 is removed. With the silicon nitride film 103 as a mask, selective oxidation is performed. A silicon oxide film 108 is formed on the surface of the polycrystalline silicon 18.

Inventors

• 👤 Fujiki Tokuyoshi
• 👤 徳吉　藤樹

Bibliographic Details