Patent ID: 7476926

Claim:
A nonvolatile storage cell comprising: a substrate; a gate conductor disposed on an upper surface of said substrate, sidewalls of said gate conductor being substantially perpendicular to said upper surface; at least one layered spacer formed at one end of said gate conductor along one sidewall of said sidewalls, said layered spacer comprising: a first isolating sidewall layer of a first dielectric material at said one Sidewall, a charge storage sidewall spacer of nitride at said first isolating sidewall layer, whereby all horizontal layer portions have been removed such that said charge storage sidewall spacer is a vertical nitride sidewall, charge being selectively stored at said charge storage sidewall spacer, said charge storage sidewall spacer consisting of a vertical nitride sidewall, said charge storage sidewall spacer being parallel to said one sidewall, a second isolating layer of said first dielectric material at said charge storage sidewall spacer, and an outboard nitride sidewall spacer at said second isolating layer; and a source/drain diffusion at each end of said gate conductor, each said at least one layered spacer extending over one said source/drain diffusion from said one sidewall at said one end of said gate conductor, said one source/drain diffusion underlapping said gate conductor and said charge storage sidewall spacer.