Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To facilitate the work of the upper layer by forming a non-oxidizable film in an element region on a semiconductor substrate, selectively oxidizing element isolation regions other than that to form a dielectric isolation film, and tapering the groove in the silicon substrate surface, thereby mitigating the step of the field oxide film. CONSTITUTION:After depositing on a semiconductor substrate 1 a silicon oxide film 2 and a silicon nitride film 3 which is a first non-oxidizable film, a boron ion implantation 4 is performed for preventing the inversion of the field edge section. Then a thin silicon nitride film 5 as a second non-oxidizable film and a silicon oxide film 6 are deposited. Then, leaving a non-oxidizable film 5' and a silicon oxide film 6' only on the sidewall sections of the non-oxidizable film 3 by anisotropical etching, a groove 7 is formed which was tapered with the reactive ion etching condition wherein a deposition and an etching occur concurrently. Further, a boron ion implantation 8 is performed for preventing the inversion of the field bottom section, the silicon oxide film 6' is removed by NH4F or the like, and a field oxidation is performed by water vapor or the like, whereupon the non-oxidizable films 3 and 5' become a mask, and a planar field oxide film 9 is formed, forming an element isolation region.

Inventors

• 👤 Akihiro Nitayama
• 👤 仁田山　晃寛

Bibliographic Details