Patent ID: 8492771
Filing Date: 2013-07-23
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a first semiconductor substrate of a first band-gap material; a second semiconductor substrate of a second band-gap material, the second band-gap material having a lower band-gap than the first band-gap material; a heterojunction formed between the first and the second semiconductor substrate in a first plane; and in a cross-section which is perpendicular to the first plane, a first semiconductor region and a second semiconductor region of a first conductivity type each extend from the second semiconductor substrate partially in the first semiconductor substrate, wherein the first and second semiconductor regions are spaced in the first semiconductor substrate in a direction parallel to the first plane by a first distance arranged in an area proximate to the heterojunction and by a second distance arranged in an area distal to the heterojunction, wherein the first distance is larger than the second distance; the first semiconductor region and the second semiconductor region being separated from each other by a first portion of a drift region of a second conductivity type which forms pn-junctions with the first semiconductor region and the second semiconductor region, the drift region extending from the second semiconductor substrate into the first semiconductor substrate and includes a portion of the heterojunction, the drift region comprising, in the first semiconductor substrate, a semiconductor region arranged at the heterojunction and comprising at the heterojunction a higher doping concentration than an adjacent region in the first semiconductor substrate; wherein the first and the second semiconductor region are spaced apart from each other in the second semiconductor substrate by a distance which is smaller than the first distance.