Buried self-sorting method and the memory array thereby made to form a semiconductor memory array of floating gate memory cells with the source line and the floating gate

摘要

A 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 source region is formed underneath the trench, and the channel region includes a first portion extending vertically along a sidewall of the trench and a second portion extending horizontally along the substrate surface. An electrically conductive floating gate is disposed in the trench adjacent to and insulated from the channel region first portion. An electrically conductive control gate is disposed over and insulated from the channel region second portion. A block of conductive material has at least a lower portion thereof disposed in the trench adjacent to and insulated from the floating gate, and can be electrically connected to the source region.