Semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To prevent the lateral diffusion of a field inversion preventing region and to prevent the production of a bird beak by forming an oxidation resistant region from the surface to the interior of a semiconductor substrate and forming a field oxidized film between the oxidation resistant regions. CONSTITUTION:A nitrided film 13 and an SiO2 film 13 are accumulated on a silicon substrate 11, the nitrided film of an element isolating region is removed with a resist film, and is etched to produce an overhang at the resist. After a protective film 15 is deposited, the resist is isolated, and the protective film on the resist is removed. Then, nitrogen ions are implanted through the gap 16 formed by side etching, thereby forming an oxidation resistant region 17. Subsequently, the film 15 is isolated, and a boron is doped. Thereafter, a field is oxidized to form a thick field oxidized film 19. Since it has the oxidiation resistant region, no bird beak is produced, and lateral diffusion of the inversion preventing region 18 can also be prevented.

Inventors

• 👤 Hiroshi Iwai

Bibliographic Details