Patent ID: 8076196

Claim:
A fabrication method for a semiconductor device, comprising the steps of: (a) forming a first insulating film on a memory cell region of a substrate; (b) forming a second insulating film on a diode region of the substrate; (c) forming a first conductive film on the first insulating film and the second insulating film; (d) selectively removing the first conductive film and the first insulating film using a mask insulating film to form a first opening in the memory cell region, and selectively removing the first conductive film and the second insulating film using the mask insulating film to form a second opening exposing the substrate in the diode region; (e) forming a bit line diffusion layer in a region of the substrate exposed in the first opening in the memory cell region; (f) forming a bit line insulating film in the first opening, said bit line insulating film filling the first opening; (g) removing the mask insulating film and forming a silicon oxide film on the first conductive film and on a region of the substrate exposed in the second opening in the memory cell region and the diode region; and (h) forming a second conductive film on the entire surface in the memory cell region and the diode region, wherein in the step (g), after removal of the mask insulating film, the silicon oxide film is formed by ozone cleaning.