Patent ID: 7868372

Claim:
A depletion-mode single-poly EEPROM cell on a substrate, wherein the substrate has a floating region and a control region, the depletion-mode single-poly EEPROM cell comprising: an isolation deep well located in the floating region of the substrate; a deep well located in the control region of the substrate; a well region located in the isolation deep well, wherein the deep well is deeper than the well region, and a depth of the deep well is similar to a depth of the isolation deep well; a floating gate comprising a first portion and a second portion, wherein the first portion is located in the floating region and the second portion is located in the control region and-the first portion and the second portion are electrically connected; source/drain regions, one source/drain region located at each side of the floating gate in the well region of the substrate and aligned with the floating gate; a heavily doped region located at one side of the floating gate in the deep well of the substrate exposed by the floating gate, and being next to and directly contacting an isolation structure in the substrate; a depletion doped region located under a tunneling dielectric layer and extending from one of the source/drain regions to another of the source/drain regions continuously, wherein the depletion doped region has a conductivity type the same as that of the source/drain regions; and a cell implant region located under a gate dielectric layer, adjacent to the heavily doped region of the substrate and directly contacting the deep well.