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(Invited) Electrothermal Performance Optimization of III-Nitride HEMTs Capped with Nanocrystalline Diamond

MetadataDetails
Publication Date2016-04-25
JournalECS Transactions
AuthorsMarko J. Tadjer, Travis J. Anderson, Tatyana I. Feygelson, Karl D. Hobart, Mario G. Ancona
InstitutionsUnited States Naval Research Laboratory, United States Navy
Citations1

AlGaN/GaN high electron mobility transistors (HEMT) capped with nanocrystalline diamond (NCD) have been demonstrated in the past to outperform electrically and thermally their SiN-passivated counterparts. However, a major process limitation for the integration of a diamond heat spreader has been the O 2 -plasma damage in the gate opening associated with etching the diamond cap. A sacrificial gate (SG) process for plasma damage-free integration of top-side NCD capping layers is thus developed. On HEMTs with a SG, the addition of a NCD cap did not cause any significant degradation in mobility, carrier density, or sheet resistance. Hall characterization showed minimal (~6%) reduction in sheet carrier density and commensurate increase in sheet resistance, while maintaining mobility and on-state drain current density. Pulsed I DS and on-resistance were improved, indicating that a 10 nm SiN/500 nm NCD could offer improved AlGaN surface passivation compared to a more conventional 100 nm thick PECVD SiN film.