A semiconductor device including a first P-type well region and an asymmetric second P-type well region each formed in a semiconductor substrate; a gate insulating layer and a gate electrode formed on the substrate; a first N-type source/drain region and a second N-type source/drain region that are formed on respective sides of the gate electrode; and an asymmetric LDD region of N-type formed to extend from the second source/drain region, wherein the asymmetric second P-type well region encompasses the second N-type source/drain region and the asymmetric LDD region, and the first N-type source/drain region both the asymmetric second P-type well region and the substrate, and the asymmetric second P-type well region is formed encompassing the second N-type source/drain region and in contact with the first N-type source/drain region.