| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor memory device capable of reducing a fluctuation in initial characteristics, deterioration in endurance and a characteristic variation, and its manufacturing method. SOLUTION: A gate length of a gate electrode 108 gradually gets longer as it comes farther away from a gate oxide film 107. A charge retention film 103 is formed with an approximately uniform thickness on a semiconductor substrate 101 via a tunnel oxide film 102, so that there is no place to which electrons accumulated in the charge retention film 103 move and the fluctuation in characteristics can be inhibited. In addition, a quantity of recombination between an electron and a hole can be suppressed, thereby inhibiting the deterioration in endurance. The tunnel oxide film 102 is formed with an approximately uniform thickness. COPYRIGHT: (C)2008,JPO&INPIT
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