Patent ID: 7208376

Claim:
A method of forming a semiconductor memory cell, comprising: forming a trench into a surface of a semiconductor substrate, wherein the substrate has a first conductivity type and the trench includes a sidewall; modifying a shape of the trench sidewall so that the trench sidewall meets the substrate surface at an acute angle to form a sharp edge; forming first and second spaced-apart regions of a second conductivity type in the substrate with the first region formed underneath the trench, wherein a channel region is defined in the substrate between the first and second regions such that the channel region includes a first portion that extends substantially along the trench sidewall and a second portion that extends substantially along the substrate surface; forming an electrically conductive floating gate having at least a lower portion thereof disposed in the trench adjacent to and insulated from the channel region first portion; and forming an electrically conductive control gate disposed over and insulated from the channel region second portion; wherein the channel region first and second portions are non-linear with respect to each other, with the channel region second portion extending from the second region in a direction toward the sharp edge and the floating gate to define a path for programming the floating gate with electrons via hot electron injection.