ELECTRICALLY ERASABLE AND PROGRAMMABLE READ ONLY MEMORY WITH NON-UNIFORM DIELECTRIC THICKNESS

摘要

An electrically erasable and programmable read only memory (EEPROM) is provided with an insulated control gate and an insulating floating gate in a trench in a semiconductor body. A dielectric layer is disposed along the sidewalls of the trench to separate the floating gate and the semiconductor body. The thickness of the dielectric layer along at least one sidewall of the trench is greater than the thickness of the dielectric layer along the other sidewalls of the trench in order to increase the programming speed due to a higher electric field in the gate oxide along the remaining sidewalls.