Patent ID: 8212310
Filing Date: 2012-07-03
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor layer of a first conductivity type; a deep well of a second conductivity type formed in a portion of an upper layer portion of the semiconductor layer; a well of the first conductivity type formed in a portion of an upper layer portion of the deep well; a source layer of the second conductivity type formed in the well; a drain layer of the second conductivity type formed in the well apart from the source layer; a gate electrode provided in a region directly above a region between the source layer and the drain layer; a gate insulation film provided between the well and the gate electrode; and a second well of the first conductivity type, formed between the deep well and the source layer in the well, having an effective impurity concentration higher than that of the well, and the drain layer being electrically connected to the deep well via the well by applying a driving voltage between the source layer and the drain layer.