| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device that is formed by preventing a large amount of junction leakage from occurring or by preventing a junction breakdown voltage from being deteriorated. SOLUTION: The nonvolatile semiconductor memory device comprises memory strings in which a plurality of memory cell transistors each having a storage part are arrayed in series, a first select transistor connected to one end of each of the memory strings, a second select transistor connected to the other end of each of the memory strings, a first impurity diffusion region that is formed in a semiconductor substrate so as to constitute a first main electrode of the first select transistor, and a second impurity diffusion region that is formed in the semiconductor substrate so as to constitute a second main electrode of the second select transistor. A depth of the first impurity diffusion region is deeper than that of the second impurity diffusion region. COPYRIGHT: (C)2010,JPO&INPIT
|
