Patent ID: 7948031

Claim:
A semiconductor device comprising: a first conductive type first drain region; a first conductive type second drain region formed on said first drain region and having an impurity concentration lower than an impurity concentration of said first drain region; a lead-out portion of said first drain region formed so as to reach said first drain region through said second drain region; a second conductive type base region formed on said second drain region; a first conductive type source region formed on said base region; a gate electrode formed through an insulating film in a groove having a first side surface adjacent to said source region and said base region; and a second conductive type first impurity region formed adjacent to a second side surface of said groove between said groove and said lead-out portion so as to extend downward beyond a lower end of said groove, wherein said first impurity region has an impurity concentration lower than an impurity concentration of said base region.