Patent ID: 6617652
Filing Date: 2003-09-09
Classification: H01L

Abstract:
A high breakdown voltage semiconductor device comprising:a semiconductor layer of a first conductivity type; a drain offset diffusion region of a second conductivity type formed in the semiconductor layer of the first conductivity type; a source diffusion region of the second conductivity type formed in the semiconductor layer of the first conductivity type apart from the drain offset diffusion region; a drain diffusion region of the second conductivity type formed in the drain offset diffusion region; a buried diffusion region of the first conductivity type that is buried in the drain offset diffusion region and at least a part of which is electrically connected to the semiconductor layer of the first conductivity type; a gate insulating film formed on a portion of the semiconductor layer of the first conductivity type that is positioned between the source diffusion region and the drain offset diffusion region; a gate electrode formed on the gate insulating film; a field insulating film formed on the drain offset diffusion region; at least one plate electrode in a floating state formed on the field insulating film; an interlayer insulating film formed on the field insulating film and the at least one plate electrode; and a metal electrode that is formed on the interlayer insulating film positioned on the at least one plate electrode and a part of which is electrically connected to the drain diffusion region and that is capacitively coupled to the at least one plate electrode.