Patent ID: 7550342
Filing Date: 2009-06-23
Classification: H01L

Abstract:
1. A method of manufacturing a nonvolatile semiconductor memory device whose gate structure of a transistor other than a memory cell transistor has a same stacked gate structure as the memory cell transistor, the method of making the gate structure comprising: successively depositing a first insulation film, a first doped polysilicon film and a second insulation film on a semiconductor substrate; depositing a second undoped polysilicon film on the second insulation film; selectively removing the second undoped polysilicon film until the second insulation film is exposed, using a photoresist film having a first opening with a first opening width; depositing, after the photoresist film is removed, a third doped polysilicon film on a surface of the substrate; selectively removing, by RIE, the third doped polysilicon film and the second insulation film in a vertical direction from a bottom of the first opening, using the third doped polysilicon film as a spacer, to define a second opening with a second opening width that is less than the first opening width; and forming a conductive film on the surface of the substrate.