Low Parasitic Heterojunction Bipolar Power Transistors

Period of Performance: 10/15/1998 - 08/15/1999


Phase 1 SBIR

Recipient Firm

Widegap Technology, LLC
5655 Lindero Canyon RoadSuite 404
Westlake Village, CA 91362
Principal Investigator

Research Topics


WiTech, in collaboration with UCSB, proposes to develop Gallium Nitride (GaN) based transferred substrate HBT transistor technology for highly linear and efficient broadband microwave power amplifier applications. WiTech has been actively developing GaN based materials technology for microwave power HEMTs. A transferred substrate HBT technology that minimizes the parasitic base-collector capacitance thereby resulting in very high fmax (> 400 GHz) transistors, has been demonstrated at UCSB. The ability to merge the aforementioned high performance technologies would lend WiTech a key advantage in developing GaN based transferred substrate HBTs. GaN based transferred substrate HBTs would enable an extremely low parasitic HBT technology capable of operating at very high power levels at microwave frequencies. A necessary feature of the transferred substrate technology is the presence of an etchable substrate. In order to facilitate this, WiTech proposes to develop the AlGaN/GaN based HBT structure on Silicon substrates. In the phase I contract, WiTech will investigate growth of GaN on Silicon and address the fabrication of the HBT base-emitter junction. The full-scale development of the HBT and circuit applications will be part of a Phase II effort. Transferred substrate AlGaN-GaN HBTs on Si substrates would combine the advantages of a low parasitic-high performance HBT technology, high power operation realizable from GaN based materials and the economies of scales of Silicon. This would make it possible to develop high power, broadband (1-5 GHz and 5-25 GHz), linear (3'rd order products 28 dB down) and efficient (> 60 %) amplifier modules.