Method of fabricating a planar structure charge trapping memory cell array with rectangular gates and reduced bit line resistance

Abstract

A method of fabricating a planar architecture charge trapping dielectric memory cell array with rectangular gates comprises fabricating a multi-layer charge trapping dielectric on the surface of a substrate. The layer adjacent to the substrate may be an oxide. A polysilicon layer is deposited over the charge trapping dielectric. A word line mask is applied over the polysilicon layer to mask linear word lines in a first direction and to expose trench regions there between and the trenches are etched to expose the charge trapping dielectric in the trench regions. A bit line mask is applied over the polysilicon layer to mask gates in a second direction perpendicular to the first direction and to expose bit line regions there between and the bit lines are etched to expose the oxide in the bit line regions. The bit lines are implanted and insulating spacers are fabricated on exposed sidewalls. The oxide is removed to expose the substrate between insulating spacers in the bit line regions and a conductor is fabricated thereon to enhance conductivity of each bit line.