TW359022B - Semiconductor cell internal static discharge protection circuit - Google Patents

Abstract

Method of forming a semiconductor cell internal static discharge protection circuit, including the following steps: provision of a P-type semiconductor substrate; forming an N-type region on the substrate, in overlap with the n' region to be formed later on, and of a higher thickness than the n' region, of a dopant density in said N-region lower than that of the n' region; forming on said semiconductor substrate a field oxide layer, and the rest of the semiconductor substrate a thin oxide layer; forming with a conductive substance on said thin oxide layer a gate electrode; and forming of the n' region on the surface of the semiconductor substrate not being covered by said gate electrode and field oxide layer.