| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device which can improve writing characteristics without complicating a manufacturing process. <P>SOLUTION: A nonvolatile semiconductor storage device comprises: an annular floating gate arranged to surround a source region; and the source region arranged inside the floating gate and a drain region arranged outside the floating gate, which are formed annularly. Compared with a memory transistor of a nonvolatile semiconductor storage device in the past, a W length can be longer, and a current amount which is to be a source of hot carriers and a drain end region where hot carriers are easily generated can be increased by forming a memory transistor annularly. Increase in the number of generated hot carriers can improve writing characteristics. In addition, because a structure of a nonvolatile semiconductor storage device manufactured in the present embodiment can be manufactured by a nonvolatile semiconductor storage device manufacturing method in the past, the writing characteristics can be improved without increasing the number of manufacturing processes. <P>COPYRIGHT: (C)2013,JPO&INPIT |
