Patent ID: 7547950
Filing Date: 2009-06-16
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor layer; a drain region, which is formed in the semiconductor layer; a source region, which is formed in the semiconductor layer; a back gate region, which is formed in the semiconductor layer; a gate oxide film formed on the semiconductor layer; and a gate electrode formed on the gate oxide film, wherein a first diffusion layer of one conductivity type is formed in the semiconductor layer so as to extend across regions where the drain region and the back gate region are formed, a diffusion layer of an opposite conductivity type constituting the back gate region is formed in the first diffusion layer of the one conductivity type, a second diffusion layer of the one conductivity type constituting the source region is formed in the diffusion layer of the opposite conductivity type, and an impurity concentration peak of the diffusion layer of the opposite conductivity type is formed in a deeper portion of the first diffusion layer of the one conductivity type than a junction region between the diffusion layer of the opposite conductivity type and the second diffusion layer of the one conductivity type.