Patent ID: 6716718
Filing Date: 2004-04-06
Classification: H01L

Abstract:
A method of producing a semiconductor device, the method comprising the steps of:forming a first film having a dielectric property, a second film having an oxidation property different from that of said first film, and a layer serving as a mask material successively on a semiconductor substrate; forming a mask pattern for forming a trench in said semiconductor substrate by performing an etching treatment on said first film, said second film, and said layer serving as a mask material; forming a trench by performing an etching treatment on said semiconductor substrate using said mask pattern as a mask; a retreating step of performing an etching treatment so that a position of a side surface of said second film exposed on a side surface of said mask pattern will be retreated from a position of a side surface of said first film; a thermal treatment step of forming an oxide film on a surface of said first film and said trench including the retreated side surface of said second film by performing a thermal treatment; and forming a buried dielectric film on said oxide film so as to fill said trench, wherein, in said retreating step, the side surface of said second film is retreated in advance so that the oxide film that has grown on the side surface of said second film may not be hung over the oxide film that has grown on the side surface of said first film after said thermal treatment step is performed.