Patent ID: 7456451
Filing Date: 2008-11-25
Classification: H01L

Abstract:
1. An ultra high voltage metal-oxide-semiconductor (MOS) transistor device, comprising: a substrate of a first conductivity type; a source region of a second conductivity type formed in the substrate; a first doping region of the first conductivity type formed in the substrate and bordering upon the source region; a first ion well of the first conductivity type encompassing the source region and the first doping region; a gate oxide layer formed on the source region and on the first ion well; a field oxide layer connected with the gate oxide layer and formed on a semiconductor region; a dielectric layer stacked on the field oxide layer, wherein the dielectric layer is thicker than the field oxide layer; a drain region of the second conductivity type formed at one side of the field oxide layer and being spaced apart from the source region; a second ion well of the second conductivity type encompassing the drain region; and a gate disposed on the gate oxide layer and laterally extending to the field oxide layer and onto the dielectric layer.