A heterojunction bipolar transistor comprising a semiconductor substrate of a first conductive-type, a first conductive-type layer of 3c-SiC, a second conductive-type layer of Si and another first conductive-type layer of 3c-SiC. The two first conductive-type layers serve respectively as collector region...http://www.google.es/patents/US5247192?utm_source=gb-gplus-sharePatente US5247192 - Heterojunction bipolar transistor
