| 摘要 |
PROBLEM TO BE SOLVED: To enhance charge injection efficiency by improving retention characteristics and charge retention characteristics. SOLUTION: A non-volatile semiconductor storage device has a semiconductor layer supported on a semiconductor board or a board, an insulation layer formed on the surface area CH and including in the inside a charge accumulation layer FG in which charge is injected from a board side, and a control electrode on the insulation film. It has a bottom insulation film BTM including an area different in nitrogen concentration in the film thickness direction between the semiconductor surface area CH of the board side and the charge accumulation layer FG. The nitrogen concentration distribution in the film thickness direction has the maximum value, and the peak is unevenly distributed on the board side from the film thickness center of the bottom insulation film BTM. Furthermore, nitrogen concentration is low in the neighborhood of an interface with the semiconductor surface area CH, and increases toward the inside of the bottom insulation film. The nitrogen concentration distribution of the bottom insulation film BTM exposes the semiconductor surface area CH to plasma containing nitrogen atoms, and is obtained by nitriding.
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