According to this invention, a semiconductor non-volatile memory device includes a semiconductor substrate, insulating films formed on the semiconductor substrate and having at least two types of gate insulating films having different thicknesses and a first conductive film formed on the insulating films...http://www.google.es/patents/US5532181?utm_source=gb-gplus-sharePatente US5532181 - Method of manufacturing semiconductor non-volatile memory device having different gate insulating thicknesses
Method of manufacturing semiconductor non-volatile memory device having ...
