摘要 |
An electrically-erasable electrically-programmable read only memory (EEPROM) transistor is programmed and erased by electron tunneling and reduces gate induced drain leakage. The EEPROM transistor comprises a semiconductor substrate having source and drain regions disposed horizontally apart. A floating gate conductor is vertically adjacent to and spaced from the source and drain regions. An insulation layer is disposed between the floating gate conductor and the source and drain regions. A first segment of the insulation layer, which is between the drain region and a minor portion of the floating gate conductor, has a first thickness. A second segment of the insulation layer which is adjacent to the first layer and the remainder on the floating gate conductor, has a second thickness which is substantially greater than the first thickness. A low density diffusion area is defined within a segment of the semiconductor substrate which extends from the drain region, encompasses the first segment of the insulation layer, to underneath a portion of the second segment of the insulation layer.
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