US Patent 7408219 Nonvolatile semiconductor memory device

In a nonvolatile semiconductor memory device, and a method of fabricating the same, the nonvolatile semiconductor memory device includes a cell doping region and source/drain regions in a semiconductor substrate, the cell doping region being doped as a first conductive type, a channel region disposed between the source/drain regions in the semiconductor substrate, a tunnel doping region of the first conductive type formed in a predetermined region of an upper portion of the cell doping region, the tunnel doping region being doped in a higher concentration than that of the cell doping region, a tunnel insulating layer formed on a surface of the semiconductor substrate on the tunnel doping region, a gate insulating layer surrounding the tunnel insulating layer and covering the channel region and the cell doping region exposed beyond the tunnel doping region, and a gate electrode covering the tunnel insulating layer and on the gate insulating layer.