Patent ID: 6268268
Filing Date: 2001-07-31
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device comprising:(a) forming a first oxide film and then a first silicon nitride film on a surface semiconductor layer of an SOI substrate, the SOI substrate comprising the surface semiconductor layer formed on a support substrate with the intervention of a buried insulating film;(b) patterning the first silicon nitride film into a desired shape and performing a first LOCOS oxidization using the thus patterned first silicon nitride film as a mask to form a first LOCOS oxide film in a region for device isolation in the surface semiconductor layer;(c) selectively removing the first LOCOS oxide film,(d) forming sidewall spacers of a second silicon nitride film on sidewalls of the first silicon nitride film and the first oxide film;(e) performing a second LOCOS oxidization using the first silicon nitride film and the sidewall spacers as a mask to form a second LOCOS oxide film which is thinner than the first LOCOS oxide film; and(f) removing the first and second silicon nitride films.