Patent ID: 8742500
Filing Date: 2014-06-03
Classification: H01L

Abstract:
1. A semiconductor device having an active region through which current flows and a peripheral region which encloses the active region and maintains breakdown voltage, comprising: a first conductivity type semiconductor substrate; a drift layer comprising first and second conductivity type semiconductor regions of column-shape or layer-shape deposited in a vertical direction on a main surface of the first conductivity type semiconductor substrate, the drift layer comprising alternately adjacent parallel pn layers in a direction along the main surface, wherein the second conductivity type semiconductor region of the parallel pn layers has an impurity concentration distribution such that the impurity concentration decreases from the surface of the pn layers toward the semiconductor substrate side; a first conductivity type surface region disposed on the parallel pn layers in the peripheral region; two or more second conductivity type guard rings disposed separately from each other on the first conductivity type surface region; and a conductive field plate disposed on each of the inner and outer circumferential side of the guard rings, and electrically connected to the surface of each of the guard rings wherein the thickness of the first conductivity type surface region disposed on the parallel pn layers in the peripheral region is one third or less of that of the parallel pn layers in the active region.