| 摘要 |
PROBLEM TO BE SOLVED: To obtain a nonvolatile semiconductor memory employing a pseudo- ground system in which writing and erasure are performed using an FN tunnel current by feeding a tunnel current only between a drain diffusion layer and the floating gate of one of two memory cells contiguous to a diffusion layer. SOLUTION: The nonvolatile semiconductor memory comprises a semiconductor substrate 1, memory cells C formed thereon in matrix each comprising a first insulation film 3, a floating gate 5, a second insulation film 6, a control gate 7 and a diffusion region 2, word lines and bit lines. In such a nonvolatile semiconductor memory, a tunnel current flows between a drain diffusion layer 2a and the floating gate 5 of one of two memory cells contiguous to the diffusion layer 2 upon application of a predetermined voltage to the diffusion layer 2. The memory cell has such structure as no tunnel current flow between the diffusion layer 2 and the floating gate 5 of the other memory cell. |
