Patent ID: 8674437
Filing Date: 2014-03-18
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first gate electrode formed over a first region of a semiconductor substrate of a first conduction type, where a first transistor is to be formed, with a first gate insulation film formed therebetween; a first source region of the first conduction type formed in the semiconductor substrate on one side of the first gate electrode; a first drain region of the first conduction type formed in the semiconductor substrate on the other side of the first gate electrode; a first channel dope layer of a second conduction type formed in at least a region on a side of the first source region of a first channel region between the first source region and the first drain region, the first channel dope layer having, at a part of the first channel dope layer on a side of the first drain region, a concentration gradient of a concentration of a dopant impurity of the second conduction type, which decrease toward the first drain region; a first well of the second conduction type formed in a region of the first region except a region where the first drain region is to be formed, the first well having, at a part of the first well on a side of the first drain region, a concentration gradient of a concentration of a dopant impurity of the second conduction type, which decrease toward the first drain region; and a second well of the second conduction type formed in the first region, connected to the first well and positioned below the first well.