Atomic layer deposition of Sc2O3 for passivating AlGaN/GaN high electron mobility transistor devices
Abstract
Polycrystalline, partially epitaxial Sc2O3 films were grown on AlGaN/GaN substrates by atomic layer deposition (ALD). With this ALD Sc2O3 film as the insulator layer, the Sc2O3/AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors showed excellent electrical performance with a high Ion/Ioff ratio of over 108 and a low subthreshold slope of 75 mV/dec. The UV/NH4OH surface treatment on AlGaN/GaN prior to ALD was found to be critical for achieving these excellent figures. In addition, the Sc2O3 dielectric is found to be negatively charged, which facilitates the enhancement-mode operation. While bare Sc2O3 suffers from moisture degradation, depositing a moisture blocking layer of ALD Al2O3 can effectively eliminate this effect.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 03, 2012
- Source ID
- 10.1063/1.4770071
Entities
People
- Bin Xi
- Omair I. Saadat
- R. J. Molnar
- Roy G. Gordon
- Tomás Palacios
- Xiabing Lou
- Xinwei Wang
Organizations
- Harvard University
- Massachusetts Institute of Technology
- National Science Foundation
- Office of Naval Research
- United States Department of Energy