Nonvolatile semiconductor storage device with charge storage layer and its manufacturing method

Abstract

A method of manufacturing a nonvolatile semiconductor storage device includes sequentially forming a charge storage film, a conductive film, and a mask film on a semiconductor substrate, sequentially removing the mask film, the conductive film, and the charge storage film at a given portion to form a groove, forming a word gate electrode to fill in the groove whose inside is covered with an insulating film, after said forming the word gate electrode, removing the mask film, after said removing the mask film, forming a spacer film to cover the conductive film and the word gate electrode, etching back the spacer film to form a spacer layer on both sides of the word gate electrode through the insulating film, removing the conductive film and the charge storage film to form a control gate electrode, and forming a source drain diffusion layer.

Dependencies are inferred from the claim text.