Patent ID: 7208359
Filing Date: 2007-04-24
Classification: H01L

Abstract:
1. A method of forming a semiconductor device, comprising: providing a semiconductor substrate of a first conductivity type; forming an offset second conductivity type channel transistor comprising a source and a drain each having a second conductivity type opposite to said first conductivity type, and a gate electrode, said source and said drain each being formed spatially separated from one another, said source being formed in a first conductivity type well, said drain being formed laterally adjacent to said first conductivity type well, between said source and said drain at least said drain having a high concentration second conductivity type diffusion layer surrounded by a low concentration second conductivity type diffusion layer of a concentration lower than said high concentration second conductivity type diffusion layer, one edge of said gate electrode toward said drain being formed on a thick oxide layer; and forming a normal second conductivity type well formed in said first conductivity type semiconductor substrate to be used for forming therein a first conductivity type channel MOS transistor; wherein: said low concentration second conductivity type diffusion layer and said normal second conductivity type well are formed simultaneously at a same process stage.