| 摘要 |
PROBLEM TO BE SOLVED: To increase the electric field applied to a gate insulating film, increase the number of hot electron occurrences, and thereby realize the improvement of the write-in efficiency. SOLUTION: The nonvolatile semiconductor memory device includes, between a second conductive type source region 2 and drain region 3 which are separately formed in a first conductive type semiconductor substrate 1, a second conductive type semiconductor region 4 formed separately from the source region 2 and drain region 3. In addition, on the semiconductor substrate 1 between the source region 2 and semiconductor region 4 and between the drain region 3 and semiconductor region 4, first and second floating gates 6a and 6b are mutually separated, and respectively formed through a first gate insulating film 5. Moreover, on first and second floating gates 6, and on the first gate insulating film 5 between the first and second floating gates 6a and 6b, a control gate 9 is formed respectively through an inter-gate insulating film 7 and a second gate insulating film 8. COPYRIGHT: (C)2009,JPO&INPIT
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