Patent ID: 9741872
Date: 2017-08-22
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a first electrode; a second electrode; a first semiconductor region of a first conductivity type provided between the first electrode and the second electrode; a second semiconductor region of a second conductivity type provided between the first semiconductor region and the second electrode; a third semiconductor region of the second conductivity type provided between the first semiconductor region and the second electrode, the third semiconductor region being provided beside the second semiconductor region in a second direction crossing a first direction from the first electrode toward the second electrode, and a portion of the first semiconductor region being positioned between the second semiconductor region and the third semiconductor region; and a fourth semiconductor region of the second conductivity type provided between the portion of the first semiconductor region and the second electrode, and the fourth semiconductor region having an impurity concentration greater than an impurity concentration in the second semiconductor region and an impurity concentration in the third semiconductor region, a distance between the fourth semiconductor region and the first electrode being greater than a distance between the second semiconductor region and the first electrode, the distance between the fourth semiconductor region and the first electrode being greater than a distance between the third semiconductor region and the first electrode, and the second semiconductor region, the third semiconductor region and the fourth semiconductor region being in direct contact with the second electrode.