Patent ID: 6048759
Filing Date: 2000-04-11
Classification: H01L

Abstract:
A method for fabricating a DMOS device supported on a substrate comprising steps of:(a) forming a thick-gate-oxide layer on said substrate followed by applying a thick-gate-oxide mask to define a plurality of thick-gate-oxide segments;(b) forming a thin-gate-oxide layer adjacent to said thick-gate-oxide segments thus defining a plurality of thick-oxide-thin-oxide interfaces, wherein said thin-gate-oxide layer having a thickness greater than one-fourth of a thickness of said thick-gate-oxide segments;(c) depositing a polysilicon layer and applying a gate mask for patterning a plurality of polysilicon segments covering over an entire length of said thick-gate-oxide segments and extended over said thick-oxide-thin-oxide interfaces thus forming a plurality of polysilicon-over-double-gate-oxide gates; and(d) implanting a body dopant into said substrate between said plurality of polysilicon-over-double-gate-oxide gates followed by a body diffusion for forming body regions with each of said body regions extending laterally under said polysilicon-over-double-gate-oxide gates wherein said body regions having a portion extending lateral beyond said thick-oxide-thin-oxide interfaces with a lateral distance less than 0.3 micrometers.