High density semiconductor memory cell and memory array using a single transistor and having variable gate oxide breakdown

Abstract

A programmable memory cell comprised of a transistor located at the crosspoint of a column bitline and a row wordline is disclosed. The transistor has its gate formed from the column bitline and its source connected to the row wordline. The memory cell is programmed by applying a voltage potential between the column bitline and the row wordline to produce a programmed n+ region in the substrate underlying the gate of the transistor. Further, a gate dielectric of the transistor has a higher breakdown voltage near the source connected to the row wordline than its drain.