Patent ID: 8120147

Claim:
A heterojunction bipolar transistor comprising: at least one emitter comprising one or more physically separate regions, each of the emitter regions comprises one or more semiconductor layers and at least one electrical contact; at least one base comprising one or more physically separate regions proximal to the emitter region or regions, where each of the base regions comprise one or more compound layers, and where each base region comprises at least one or more semiconductor layers and at least one electrical contact; the at least one base comprises at least one layer of an aluminum-bearing composition with any combination of arsenic or phosphorus or nitrogen, where at least part of the aluminum-bearing composition layer is a current blocking oxide layer; at least one collector comprising one or more physically separate regions proximal to the base region or regions and the emitter region or regions; where each collector region comprises one or more semiconductor layers and at least one electrical contact; and the physically separate regions form a linear or two dimensional regularly or irregularly spaced array.