Method of manufacturing a semiconductor device having a self-aligned structure for a split gate flash memory device

A method of manufacturing a semiconductor device, comprising the steps of:

• forming a field oxide film for isolating devices on a semiconductor substrate of a first conductivity type;
• forming a conductor layer on said semiconductor substrate and patterning said conductor layer to form a plurality of first gates and conductor patterns;
• implanting impurity ions of a second conductivity type into said substrate, to thereby form a first impurity region;
• forming an insulating film on said substrate;
• etching said insulating film so as to expose upper surfaces of said first gates and said conductor patterns;
• removing said conductor patterns;
• implanting impurity ions of said second conductivity type into said substrate where said conductor pattern is removed, to thereby form a second impurity region;
• removing said insulating film;
• forming a dielectric film on said first gates;
• and
• forming a second gate on said substrate and said dielectric film.

A method of manufacturing a semiconductor device, comprising the steps of:

• forming a gate insulating film on a surface of a substrate;
• depositing a conductor layer on said gate insulating film to form a first gate;
• forming a first impurity region in said substrate using said first gate as a mask;
• encapsulating said first gate with a dielectric film;
• forming a second gate on said dielectric film;
• forming a conductor pattern on said gate insulating film concurrently with said first gate;
• removing said conductor pattern subsequent to said first impurity region formation step;
• and
• forming a second impurity region in said substrate where said conductor pattern is removed.