E2PROM device having erase gate in oxide isolation region in shallow trench and method of manufacture thereof

摘要

An E2PROM device includes a semiconductor body having source and drain regions and a channel region, with a gate oxide over the channel region and a floating gate over the gate oxide. An oxide isolation region contains a doped polysilicon erase gate, so that erasing of the device takes place by electron flow from the floating gate to the erase gate through a thin oxide portion of the oxide isolation region, at a position spaced from the gate oxide. The inclusion of the erase gate in the oxide isolation region results in smaller overall device size than previously achieved.