Wang, XinweiSaadat, Omair I.Xi, BinLou, XiabingMolnar, Richard J.Palacios, TomásGordon, Roy2012-12-132012Wang, Xinwei, Omair I. Saadat, Bin Xi, Xiabing Lou, Richard J. Molnar, Tomás Palacios, and Roy G. Gordon. 2012. Atomic layer deposition of \(Sc_2O_3\) for passivating AIGaN/GaN high electron mobility transistor devices. Applied Physics Letters 101: 232109.0003-69511077-3118http://nrs.harvard.edu/urn-3:HUL.InstRepos:10055799Polycrystalline, partially epitaxial \(Sc_2O_3\) films were grown on AlGaN/GaN substrates by atomic layer deposition (ALD). With this ALD \(Sc_2O_3\) film as the insulator layer, the \(Sc_2O_3\)/AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors showed excellent electrical performance with a high I\(_{on}\)/I\(_{off}\) ratio of over 10\(^8\) and a low subthreshold slope of 75 mV/dec. The UV/NH\(_4\)OH surface treatment on AlGaN/GaN prior to ALD was found to be critical for achieving these excellent figures. In addition, the \(Sc_2O_3\)dielectric is found to be negatively charged, which facilitates the enhancement-mode operation. While bare \(Sc_2O_3\) suffers from moisture degradation, depositing a moisture blocking layer of ALD \(Al_2O_3\) can effectively eliminate this effect.en-USaluminium compoundsatomic layer depositionelectrical conductivityepitaxial layersgallium compoundshigh electron mobility transistorshigh-k dielectric thin filmsIII-V semiconductorsinsulating thin filmsMISFETpassivationscandium compoundswide band gap semiconductorsJournal Article2012-12-1310.1063/1.477071