Manufacturing method of non-volatile semiconductor device

Abstract

The present invention relates to a method of manufacturing a non-volatile semiconductor device having a structure in which layers of a first insulating film, a first polysilicon layer, a second insulating film and a second polysilicon layer are formed, in this order, on a semiconductor substrate; which comprises the steps of forming the first insulating film on the semiconductor substrate and thereafter forming the first polysilicon layer; patterning the first polysilicon layer; performing a heat treatment in hydrogen atmosphere; forming the second insulating film; forming the second polysilicon layer; and patterning the second polysilicon layer. In accordance with the present invention, a non-volatile semiconductor device having excellent hold characteristics and only a small dispersion of element characteristics can be manufactured.

Dependencies are inferred from the claim text.