Patent ID: 6773999
Filing Date: 2004-08-10
Classification: H01L,Y10S

Abstract:
A method for manufacturing a semiconductor device, comprising the steps of:(a) partitioning a semiconductor substrate into a first region and a second region; (b) forming a first base gate insulating film made of a thermal oxide film on the first region and the second region; (c) after the step (b), removing the first base gate insulating film in the second region; (d) after the step (c), forming a second base gate insulating film having a thickness smaller than that of the first base gate insulating film on the second region of the semiconductor substrate; and (e) after the step (d), exposing the first base gate insulating film and the second base gate insulating film to a nitrogen plasma so as to introduce nitrogen into the first base gate insulating film and the second base gate insulating film, thereby forming a first gate insulating film from the first base gate insulating film and a second gate insulating film from the second base gate insulating film, wherein nitrogen from the nitrogen plasma in the step (e) is only introduced to the surface portion of the first gate insulating film such that the nitrogen does not reach the interface between the first gate insulating film and the semiconductor substrate, and the nitrogen is introduced to the second gate insulating film, such that the nitrogen reaches the interface between the second gate insulating film and the semiconductor substrate.