Patent ID: 7372084
Filing Date: 2008-05-13
Classification: H01L

Abstract:
1. A bipolar transistor comprising: a plurality of semiconductor layers comprising a collector layer, a base layer in contact with the collector layer, a support layer in contact with the collector layer, and an emitter layer in contact with the base layer, the base layer having the opposite doping type of the collector layer and the emitter layer, wherein the plurality of semiconductor layers are formed to comprise: wherein a region of the collector layer adjacent to the extrinsic base region is selectively type converted to have the same doping type as the base layer, wherein the base layer, the emitter layer, and the collector layer comprise substantially of InAs wherein x ranges from 0 to 0.5, wherein a region of the support layer adjacent to the type converted region of the collector layer is also selectively doped with the same doping type as the base layer, and wherein the sub-collector region is not interposed between the extrinsic base region and the support layer.