Patent ID: 7119405

Claim:
An ESD protection circuit of a thick gate-oxide grounded-gate NMOSFET, said ESD protection circuit comprising: a substrate; a thick-oxide on the substrate; a first spacer on the substrate proximate the thick-oxide; and thin-oxide N-LDD implantation under the first spacer in the substrate; wherein the NMOSFET comprises an I/O which comprises a thick-oxide, a second spacer proximate the thick-oxide of the I/O, and thick-oxide N-LDD implantation disposed under the second spacer, wherein the thin-oxide N-LDD implantation has a higher doping concentration than does the thick-oxide N-LDD implantation which is disposed under the second spacer; wherein the NMOSFET comprises a core which comprises a thin-oxide, a third spacer proximate the thin-oxide of the core, and thin-oxide N-LDD implantation disposed under the third spacer, wherein the thin-oxide N-LDD implantation has substantially the same doping concentration than does the thin-oxide N-LDD implantation which is disposed under the third spacer.