Semiconductor memory array of floating gate memory cells with buried bit-line and raised source line

Abstract

A self aligned method of forming an array of floating gate memory cells, and an array formed thereby, wherein each memory cell includes a trench formed into a surface of a semiconductor substrate, and spaced apart source and drain regions with a channel region formed therebetween. The drain region is formed underneath the trench, and the channel region includes a first portion that extends vertically along a sidewall of the trench and a second portion that extends horizontally along the substrate surface. An electrically conductive floating gate is formed over and insulated from a portion of the channel region. A raised source line of conductive material is disposed over the source region, and laterally adjacent to and insulated from the floating gate. An electrically conductive control gate is formed having a first portion disposed in the trench and a second portion formed over but insulated from the floating gate.