Patent ID: 6797594
Filing Date: 2004-09-28
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device comprising a semiconductor substrate of a first conductivity type, a semiconductor layer of a first conductivity type formed on the upper surface of the semiconductor substrate, a field insulation film formed for defining a device forming region on the main surface of the semiconductor layer, a first region and a second region of a second conductivity type opposite to the first conductivity type situated, being spaced apart from each other, in the device forming region on both sides of a region to be formed with a channel, the second region comprising a low impurity concentration region in contact with a region to be formed with the channel and a high impurity concentration region in contact with the low impurity concentration region, and having a gate electrode formed by way of a gate insulation film above the channel region, and a leach-through layer of the first conductivity type formed in the device forming region so as to be in contact with the first region and the semiconductor substrate, wherein the method comprises:a step of introducing impurities for forming the leach-through layer selectively on the main surface of the semiconductor layer and not overlapped with a drain forming region, a step of forming the field insulation film selectively to the main surface of the semiconductor layer by thermal oxidation, and extending the impurities to form the leach-through layer in contact with the semiconductor substrate, a step of forming the gate insulation film to the surface of the device forming region defined by the field insulation film, a step of forming the gate electrode on the gate insulation film and then a step of forming the first region and the second region in the device forming region.