Electrically alterable, nonvolatile floating gate memory device

Claim 1

In a floating gate memory device of the type including a body of semiconductor material of a first conductivity type having first and second doped regions of a second conductivity type formed in the semiconductor body at the surface thereof, the first and second doped regions spaced one from the other to define a channel region therebetween in the semiconductor body for supporting current flow between the doped regions, a first conductive layer insulated from the body of the semiconductor material, a second conductive layer positioned over both the channel region and the first conductive layer and insulated therefrom, the first conductive layer having a first aperture therein into which the second conductive layer extends, the improvement comprising: a first portion of the channel region, adjacent the first doped region having a pair of depletion type regions embedded in the semiconductor body at the surface thereof and spaced one from the other to define a first channel portion therebetween; a second aperture in the first layer of polysilicon, aligned with the first channel portion, into which a portion of the second conductive layer extends; a second channel portion adjacent the second doped region and occupying the remainder of the channel region; and a third conductive layer positioned over and insulated from the second channel portion.