Patent ID: 7858463
Filing Date: 2010-12-28
Classification: H01L

Abstract:
1. A method of producing a semiconductor integrated circuit device, comprising the steps of: (a) forming a semiconductor structure including a tunnel insulating film covering a memory cell region of a substrate, a first silicon film covering the tunnel insulating film, an insulating film covering the first silicon film, and a gate insulating film covering a logic device region of the substrate; (b) depositing a second silicon film on the semiconductor structure formed in said step (a) so that the second silicon film covers the insulating film in the memory cell region and the gate insulating film in the logic device region; (c) forming a multilayer gate electrode structure in the memory cell region by successively patterning the second silicon film to serve as a control gate electrode, the insulating film, and the first silicon film in the memory cell region with the second silicon film being left in the logic device region; (d) forming a protection oxide film so that the protection oxide film covers the multilayer gate electrode structure in the memory cell region and the second silicon film in the logic device region; (e) forming diffusion regions in both sides of the multilayer gate electrode structure in the memory cell region by performing ion implantation of an impurity element into the substrate with the multilayer gate electrode structure and the second silicon film being employed as masks; (f) forming a gate electrode in the logic device region by patterning the second silicon film; and (g) forming diffusion regions in the logic device region by performing ion implantation with the gate electrode being employed as a mask, whereby a nonvolatile memory device is formed in the memory cell region and a semiconductor device is formed in the logic device region.