Patent ID: 7118972

Claim:
A manufacturing method of a semiconductor device for forming a rewritable nonvolatile memory cell including a first field effect transistor for memory, and forming a circuit including a second field effect transistor in different regions over a semiconductor substrate, comprising the steps of: (a) forming a first gate electrode of the first field effect transistor; (b) forming a second gate electrode of the second field effect transistor; and (c) forming first sidewall spacers over the sidewalls of the first gate electrode and second sidewall spacers over the sidewalls of the second gate electrode, said step (c) further comprising the sub-steps of: (c1) forming a first insulating film to cover therewith the first gate electrode and the second gate electrode; (c2) forming a second insulating film over the first insulating film; (c3) forming a third insulating film over the second insulating film; (c4) removing the third insulating film formed to cover the second gate electrode while leaving the third insulating film formed to cover the first gate electrode; (c5) removing the third insulating film while leaving the third insulating film over the sidewalls of the first gate electrode; (c6) removing the second insulating film while leaving the second insulating film formed over the sidewalls of the second gate electrode; and (c7) removing the second insulating film formed over the sidewalls of the second gate electrode, and removing the first insulating film while leaving the first insulating film formed over the sidewalls of the first gate electrode and the sidewalls of the second gate electrode, whereby the first sidewall spacers made of the first insulating film, the second insulating film and the third insulating film, and the second sidewall spacers made of the first insulating film are formed.