Patent ID: 7973333
Filing Date: 2011-07-05
Classification: H01L

Abstract:
1. A lateral DMOS transistor comprising: a MOS diode that has semiconductor material of a first conductivity type; a source region of a second conductivity type; a drain region of the second conductivity type; a drift region composed of semiconductor material of the second conductivity type, wherein the drain region is separated from the MOS diode by the drift region; a dielectric gate layer, which has a first region of a first thickness and a second region of a second thickness that is greater than the first thickness; a trench structure that is filled with a dielectric; and a gate electrode, which is arranged over the first region and the second region of the dielectric gate layer and arranged as a field plate over the trench structure, wherein the drift region is partially covered by the dielectric gate layer, which dielectric gate layer also covers the semiconductor material of the MOS diode; wherein the first region of the dielectric gate layer covers the semiconductor material of the MOS diode, the second region of the dielectric gate layer being positioned on an edge area of the drift region facing the MOS diode, the dielectric gate layer at least partially covering the trench structure, and the trench structure being positioned in the drift region between the drain region and the MOS diode; wherein a transition is made from the first thickness to the second thickness such that the edge area of the drift region facing the MOS diode is already positioned beneath the second region of the dielectric gate layer; and a progression of a pn junction, which separates the MOS diode from the drift region, is aligned with the progression of the transition from the first thickness to the second thickness of the dielectric gate layer.