| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device capable of obtaining both improvement of injection efficiency and simplification of manufacturing process. <P>SOLUTION: The nonvolatile semiconductor storage device comprises a memory cell 1 consisting of a first lamination part 15 in which a first impurity diffusion region 4 and second impurity diffusion region 3 of second conductive type are provided on a first conductive type semiconductor substrate 2, and between both regions, a first insulating film 5, charge accumulation layer 6, second insulating film 7, and first gate electrode 8 are stacked in the order from bottom to top, and a second lamination part in which a third insulating film 9 and second gate electrode 10 are stacked upward. The region sandwiched between the first lamination part 15 and the second lamination part 16 comprises a third impurity diffusion region 13 of second conductive type whose impurity density is set to be lower than the first and second impurity diffusion regions, being 5×10<SP>12</SP>ions/cm<SP>2</SP>or less. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
