High temperature operation to 500 °C of AlGaN graded polarization-doped field-effect transistors
Abstract
AlGaN polarization-doped field-effect transistors were characterized by DC and pulsed measurements from room temperature to 500 °C in ambient. DC current-voltage characteristics demonstrated only a 70% reduction in on-state current from 25 to 500 °C and full gate modulation, regardless of the operating temperature. Near ideal gate lag measurement was realized across the temperature range that is indicative of a high-quality substrate and sufficient surface passivation. The ability for operation at high temperature is enabled by the high Schottky barrier height from the Ni/Au gate contact, with values of 2.05 and 2.76 eV at 25 and 500 °C, respectively. The high barrier height due to the insulatorlike aluminum nitride layer leads to an ION/IOFF ratio of 1.5 × 109 and 6 × 103 at room temperature and 500 °C, respectively. Transmission electron microscopy was used to confirm the stability of the heterostructure even after an extended high-temperature operation with only minor interdiffusion of the Ni/Au Schottky contact. The use of refractory metals in all contacts will be key to ensure a stable extended high-temperature operation.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 09, 2020
- Source ID
- 10.1116/1.5135590
Entities
People
- Albert G. Baca
- Andrew A. Allerman
- Andrew Armstrong
- Brianna Klein
- E Douglas
- Fan Ren
- Patrick H. Carey
- Stephen Pearton
Organizations
- Sandia National Laboratories
- United States Department of Defense
- United States Department of Energy
- University of Florida