Patent ID: 6287912
Filing Date: 2001-09-11
Classification: H01L,Y10S

Abstract:
A method of fabricating a semiconductor device comprising n-channel field-effect transistors and p-channel field-effect transistors, and having a semiconductor substrate provided thereon with a relatively thick gate insulating film and a relatively thin gate insulating film, said method comprising the steps of:(a) forming a first insulating film in regions in a surface of the semiconductor substrate in which the relatively thick gate insulating film and the relatively thin gate insulating film are to be formed;(b) forming a mask exposing a region in which the relatively thin gate insulating film is to be formed, and covering other regions following the step (a);(c) introducing an impurity for adjusting threshold voltages of n-channel field-effect transistors and p-channel field-effect transistors having the relatively thin gate insulating film into the exposed region not covered with the mask;(d) etching parts of the first insulating film, not covered with the mask by using the mask as an etching mask following the step (c); and(e) forming the relatively thick gate insulating film and the relatively thin gate insulating film on the semiconductor substrate following the step (d).