Patent ID: 6225148
Filing Date: 2001-05-01
Classification: H01L

Abstract:
A method of fabricating a semiconductor device formed on an SOI substrate prepared by stacking a buried oxide film and an SOI layer on a silicon substrate, comprising the steps of:(a) forming a first oxide film on said SOI substrate by thermal oxidation;(b) successively forming a polysilicon film and a nitride film on said first oxide film;(c) selectively removing said nitride film and thereafter selectively removing said polysilicon film with the rest of said nitride film as a mask to form a laminated structure of a polysilicon film and a nitride film on said first oxide film;(d) forming side wall oxide films over side surfaces of said laminated structure and an upper portion of said first oxide film around said laminated structure;(e) selectively removing said SOI layer with said side wall oxide films and said laminated structure as a mask to define an active region and forming a structural body comprising said active region, said first oxide film, said laminated structure and said side wall oxide films;(f) covering said structural body with an isolation oxide film, with an upper major surface of said nitride film exposed;(g) removing said laminated structure; and(h) isotropically removing at least said side wall oxide films, said first oxide film and said isolation oxide film until exposing an upper major surface of said active region.