Monolithic fabrication of NPN and PNP AlInAs/GaInAs HBTs

The authors demonstrated the feasibility of a new technique for the monolithic fabrication of complementary heterostructure bipolar transistors (HBTs). The process led to coplanar npn and pnp HBTs, the first in the AlInAs/GaInAs material system, which were comparable with the state of the art in HBTs. These devices exhibited unity current gain cutoff frequencies (f/sub T/) up to 99 GHz and 14 GHz for the npn and pnp transistors, respectively. The fabrication scheme allows each of these device types to have individually designed epitaxial structures that are grown in a single molecular beam epitaxy run. Results show that the devices will be capable of tight packing densities for IC applications.<
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