| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device capable of suppressing variations in threshold voltage of a memory cell in a hybrid structure.SOLUTION: A nonvolatile semiconductor memory device comprises a tunnel insulating layer 13 on a semiconductor layer 10, a charge storage layer 14 on the tunnel insulating layer 13, a block insulating layer 15 on the charge storage layer 14, and a control gate electrode 16 on the block insulating layer 15. The charge storage layer 14 comprises a floating gate layer 14a on the tunnel insulating layer 13, an interface insulating layer 14b on the floating gate layer 14a, a first charge trap layer 14c-1 on the interface insulating layer 14b, and a second charge trap layer 14c-2 on the first charge trap layer 14c-1. A trap level of the second charge trap layer 14c-2 is lower than a trap level of the first charge trap layer 14c-1. |
