Patent ID: 6518144
Filing Date: 2003-02-11
Classification: H01L,Y10S

Abstract:
A process for a semiconductor device having a trench including:the step of forming a trench in a main surface of a semiconductor substrate; the step of forming a first insulating film on the main surface of said semiconductor substrate in one step, or in a plurality of divided steps, so as to fill in said trench and to have a void in said trench; the step of forming an aperture which reaches to the inside of said trench in said first insulating film by connecting said void with the outside of said trench through an anisotropic etching in said first insulating film so that the upper edge corner parts of said aperture in said first insulating film have a more round edge than the upper edge corner parts of said trench and of reducing the film thickness of said first insulating film on the main surface of said semiconductor substrate; and the step of forming a second insulating film on the main surface of said semiconductor substrate in one step, or in a plurality of divided steps, so as to fill in said aperture.