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oai:www.ideals.illinois.edu:2142/81312 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Adesida, Ilesanmi Ping, Andrew Taiann 2015-09-25T20:10:30Z 2015-09-25T20:10:30Z 10000-01-01 1999 1999 The fabrication of AlGaN/GaN HFETs entailed first developing fundamental processing techniques such as isolation etching, low-resistance drain/source ohmic contacts, and Schottky gate formation. These efforts along with related processing issues will be discussed. Devices were then fabricated on epitaxial layers grown on sapphire substrates and on n-type, p-type, and insulating SiC. While sapphire is the substrate of choice for the nitrides, SiC substrates are better suited for high-power devices due to their significantly higher thermal conductivity. The dc, RF, and high-temperature performance of transistors on sapphire and SiC were investigated to determine the performance similarities and differences between using the various substrates. Forming low-resistance ohmic contacts to the wide bandgap heterostructures is difficult and as a result limits the overall device performance. In an effort to improve drain-source contacts, gate recessing through the use of low-damage inductively coupled plasma reactive ion etching was pursued. A wet chemical etching process called photoelectrochemical etching was also investigated. Made available in DSpace on 2015-09-25T20:10:30Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9953111.pdf: 4510186 bytes, checksum: 4b93946da26d4102c593b57c979a3bfd (MD5) Previous issue date: 1999 Embargo set by: Seth Robbins for item 82593 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 101 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1999. http://hdl.handle.net/2142/81312 (MiAaPQ)AAI9953111 eng Engineering, Electronics and Electrical Process Development and Characterization of AlGaN/GaN Heterostructure Field-Effect Transistors text Electrical Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.