Bipolar junction transistors (BJTs) and single or double heterojunction bipolar transistors with low parasitics, and methods for making the same is presented. A transistor is fabricated such that the collector region underneath a base contact area is deactivated. This results in a drastic reduction of the base-collector parasitic capacitance, C.sub.bc. An embodiment of the present invention provides a transistor architecture for which the base contact area can be decoupled from the collector and hence allows for dramatic reduction in the parasitics of transistors.