Semiconductor device with a non-uniformly doped channel

Claim 1

A semiconductor device with a non-uniformly and lightly doped channel comprising a gate electrode having side walls formed on a gate oxide dielectric film, said gate oxide dielectric film being formed on a silicon substrate of a first conductivity type film; an extension extending from and in contact with each side wall of the gate electrode, the extensions being composed of a thin polysilicon layer on the gate oxide dielectric film, said thin polysilicon layer being substantially thinner than the gate electrode; the silicon substrate including a channel region, said channel region having a central portion which is doped with ions of a first conductivity type at a concentration higher than in the silicon substrate and edge portions located below each thin polysilicon layer extension doped with ions of the first conductivity type at a concentration higher than in the central portion, and having at an outer region of the channel region source-drain regions doped with ions of a second conductivity type.