Heterojunction bipolar transistor for power switching applications
Abstract
The design, fabrication, and analysis of an aluminum gallium nitride/4H silicon carbide heterojunction bipolar transistor for power switching applications are discussed. Due to a number of processing improvements over previously reported AlGaN/SiC HBT's in the scientific literature, this device was able to demonstrate for the first time operation in common-emitter mode. The devices produced a common-emitter gain less than unity, and the reasons for this are thoroughly investigated. Preliminary experiments on AlGaN/4H-SiC heterojunction diodes are also discussed, in which the aluminum alloy fraction and SiC surface preparation were varied to investigate their effect on the hetero-interface quality. Optimization of a number of unit processes including unbuffered selective area growth and ohmic contact formation are reviewed. Future design and process improvements for the HBT's are proposed.
Degree
Ph.D.
Advisors
Capano, Purdue University.
Subject Area
Electrical engineering|Materials science
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