High temperature operation to 500 °C of AlGaN graded polarization-doped field-effect transistors
- Univ. of Florida, Gainesville, FL (United States)
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
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.
- Research Organization:
- Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC04-94AL85000
- OSTI ID:
- 1634786
- Alternate ID(s):
- OSTI ID: 1632907
- Report Number(s):
- SAND2020--4176J; 685407
- Journal Information:
- Journal of Vacuum Science and Technology B, Journal Name: Journal of Vacuum Science and Technology B Journal Issue: 3 Vol. 38; ISSN 2166-2746
- Publisher:
- American Vacuum Society / AIPCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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