Patent ID: 6335553
Filing Date: 2002-01-01
Classification: H01L

Abstract:
A nonvolatile semiconductor memory cell comprising:a semiconductor substrate of a first conductivity type; a common source region of a second conductivity type in a first direction within the substrate; a first drain region and a second drain region of the second conductivity type in the first direction within the substrate; an insulating film on the substrate; an insulating island in direct contact with the insulating film above the common source region and also in direct contact with the insulating film to a second side of the common source region nearest the second drain region; a conductive first floating gate on the insulating film to a first side of the common source region nearest the first drain region, the first floating gate being contiguous to the insulating island; a conductive second floating gate on the first floating gate and also on the insulating island; a dielectric film on exposed surfaces of both the first and second floating gates; and a conductive control gate in a second direction on the dielectric film on the second floating gate.