Abstract: The write performance and erasion performance of a nonvolatile semiconductor memory having as its memory elements MOSFETs in each of which a floating gate electrode is formed on each of the two sidewalls of a control gate electrode are to be improved, and the read performance is also to be improved. Part of the control gate electrode is extended above the floating gate electrodes on its two sidewalls. A source region and a drain region are formed alongside the outer boundaries of the floating gate electrodes so,that electric charges can be separately injected into the two floating gate electrodes.

Abstract: The write performance and erasion performance of a nonvolatile semiconductor memory having as its memory elements MOSFETs in each of which a floating gate electrode is formed on each of the two sidewalls of a control gate electrode are to be improved, and the read performance is also to be improved. Part of the control gate electrode is extended above the floating gate electrodes on its two sidewalls. A source region and a drain region are formed alongside the outer boundaries of the floating gate electrodes so that electric charges can be separately injected into the two floating gate electrodes.