Patent ID: 8828830

Claim:
A method of manufacturing a semiconductor device comprising the steps of: (a) selectively etching a silicon substrate to form trench defining active region; (b) forming a first silicon nitride layer above a surface of said trench; (c) forming an insulator burying a recess defined by said first silicon nitride layer; (d) forming a p-channel MOS transistor on said active region; (e) forming a second silicon nitride layer above said silicon substrate, said second silicon nitride layer covering said p-channel MOS transistor; (f) forming a first insulating film above said second silicon nitride layer; (g) forming a third silicon nitride layer having a ultraviolet shielding ability above said first insulating film; and (h) forming a second insulating film containing silicon and oxygen above said third silicon nitride layer; wherein said step (e) forms the second silicon nitride layer having a first Si composition by thermal CVD, said step (f) forms the first insulating film by thermal CVD, and said step (g) forms the third silicon nitride layer having a second Si composition larger than the first Si composition by plasma CVD.