Patent ID: 6469346
Filing Date: 2002-10-22
Classification: H01L

Abstract:
A high-breakdown-voltage semiconductor device comprising:a semiconductor substrate; a body layer of a first conductivity type selectively formed on a region of a surface of the semiconductor substrate; a source layer of a second conductivity type selectively formed in a surface of the body layer; a drain layer of the second conductivity type selectively formed on the surface of the semiconductor substrate apart from the body layer; a second layer of the second conductivity type formed on the surface of the substrate between the body layer and the drain layer, the second layer being apart from the body layer; a source electrode formed to contact a surface of the body layer and a surface of the source layer; and a gate electrode formed on at least a region of the body layer located between the source layer and the drain layer, the gate electrode being apart from the drain layer and the second layer, with an insulating film interposed between the gate electrode and the region of the body layer; wherein, under conditions that a voltage is applied between the drain layer and the body layer, and a gate voltage having the same polarity as a drain voltage to be applied to the drain layer, within a rated gate voltage range, the rated gate voltage being a gate voltage range applicable to the gate electrode in a normal operation, and over a threshold voltage of the semiconductor device, is applied to the gate electrode, a breakdown voltage between the drain layer and the body layer is larger than a half of a breakdown voltage between the drain layer and the body layer with the gate voltage set at 0 volts.