| 摘要 |
An EEPROM according to the present invention includes: a semiconductor layer of a first conductive type; and a first insulating film formed on the semiconductor layer. A first impurity region, a second impurity region, a third impurity region, a fourth impurity region, and a fifth impurity region of a second conductive type are formed in top layer portions of the semiconductor layer. On the first insulating film, a select gate, a first floating gate, and a second floating gate are respectively disposed opposite a region between the first impurity region and the second impurity region, a region between the second impurity region and the third impurity region, and a region between the third impurity region and the fourth impurity region. In the first insulating film, a first tunnel window and a second tunnel window are respectively formed at portions in contact with the first floating gate and the second floating gate. A sixth impurity region of the second conductive type, which is connected to the second impurity region, is formed in a portion of the top layer portion of the semiconductor layer that opposes the second tunnel window.
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