Patent ID: 7227217

Claim:
A bi-directional non-volatile memory cell comprising: a substrate of a substantially single crystalline semiconductive material having a first conductivity type, said substrate having a substantially planar surface with a first trench and a second trench in said surface, spaced apart from one another; with each trench having a bottom wall and a side wall; a first region of a second conductivity type along said bottom wall of said first trench; a second region of said second conductivity type along said bottom wall of said second trench; a channel region between said first region and said second region, said channel region having a first portion, a second portion, and a third portion, with said first portion along said sidewall of said first trench, a second portion along said surface of said substrate between said first and second trenches, and said third portion along said sidewall of said second trench; a control gate insulated from said second portion of said channel region; a first floating gate adjacent to said control gate and insulated therefrom, and insulated from said first portion of said channel region, said first floating gate having a tip; a second floating gate adjacent to said control gate and insulated therefrom, and insulated from said third portion of said channel region, said second floating gate having a tip; an erase gate insulated from said control gate and said tips of said first and second floating gates; and an insulating material between said tips of said first floating gate and said second floating gate and said erase gate permitting charges to tunnel from said tips to said erase gate.