Patent ID: 7361553

Claim:
A method of manufacturing a semiconductor device comprising a nonvolatile memory and a MOS transistor, comprising: providing a semiconductor substrate; forming a first insulation film on the substrate; forming on the first insulation film a stack of a floating gate and a selective oxidation insulation film disposed on the floating gate; forming a second insulation film on the first insulation film and the stack; forming an anti-oxidation film on the second insulation film; patterning the anti-oxidation film; thermally oxidizing the substrate using the patterned anti-oxidation film as a mask to form a third insulation film; patterning the second insulation film after the thermal oxidation; forming a nonvolatile memory that includes the stack and the patterned second insulation film as a tunnel insulation film; and forming a MOS transistor that includes the third insulation film as a gate insulation film.