800 ∘C Air-Ambient Operation of Extreme-Bandgap AlxGa1−xN (x>0.6) Digital and Random-Alloy Channel HEMTs
Abstract
This work demonstrates the high-temperature (room to 800 ∘C) operation of thin Al0.62Ga0.38N digital alloy (DA) short-period superlattice (SPSL), and random alloy (RA) Al0.64Ga0.36N channel MOSHEMTs on sapphire. The RA devices employ a doped n+-85%-Al barrier and a highly doped n++-Al0.86→0.20Ga0.14→0.80N reverse-graded layer (RGL) for surface ohmic contact formation, whereas the DA devices employ a binary AlN barrier and selectively regrown n++-GaN source/drain contacts. At 800 ∘C, the DA channel devices exhibit better thermal stability: their saturated drain current decreases from 460 to 172 mA/mm (62.6%) compared with 338 to 98 mA/mm (71.0%) for the RA channel, and a lower subthreshold swing (459 for DA versus 550 mV/dec for RA). All tested DA devices also exhibit superior threshold-voltage stability (<± 10% versus >± 19% for RA) and maintain an ON/OFF current ratio >104 at 800 ∘C, compared with ~103 for RA, thus establishing the DA channel HEMTs as a promising new platform for high-temperature electronics.
Related
- Single-step initialization of a 16-channel silicon nitride DWDM demultiplexer using a physics-informed digital twin
- Scaling the Wavelength to Optimize Ultrafast Laser Processing of Bandgap Materials
- Direct growth of crystalline spinel GaON films: A wide-bandgap mixed-anion semiconductor
- Tailoring bandgap and electron affinity of spacecraft dielectrics for synergistic solar array charging and discharge suppression
- Intra-bandgap Bound-State Magnonics in a Photonic Crystal Waveguide
BibTeX
@misc{mazumder2026airambient,
title = {{800 $^\circ$C Air-Ambient Operation of Extreme-Bandgap Al$_x$Ga$_1-x$N (x>0.6) Digital and Random-Alloy Channel HEMTs}},
author = {Abdullah Al Mamun Mazumder and Tariq Jamil and Mafruda Rahman and Muhammad Ali and Ankit Malik and Anthony Joyce and Patrick Darmawi-Iskandar and Chandan Joishi and Mansura Sadek and James G. Fiorenza and Manoj Kumar Chandra Mohan and Grigory Simin and Tomás Palacios and Asif Khan},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.39053},
eprint = {2610.39053},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.39053},
}
RIS
TY - UNPB
TI - 800 ^∘C Air-Ambient Operation of Extreme-Bandgap Al_xGa_1−xN (x>0.6) Digital and Random-Alloy Channel HEMTs
AU - Abdullah Al Mamun Mazumder
AU - Tariq Jamil
AU - Mafruda Rahman
AU - Muhammad Ali
AU - Ankit Malik
AU - Anthony Joyce
AU - Patrick Darmawi-Iskandar
AU - Chandan Joishi
AU - Mansura Sadek
AU - James G. Fiorenza
AU - Manoj Kumar Chandra Mohan
AU - Grigory Simin
AU - Tomás Palacios
AU - Asif Khan
PY - 2026
DA - 2026/10/28
PB - arXiv
DO - 10.48550/arxiv.2610.39053
UR - https://arxiv.org/abs/2610.39053
AB - This work demonstrates the high-temperature (room to 800 ^∘C) operation of thin Al_0.62Ga_0.38N digital alloy (DA) short-period superlattice (SPSL), and random alloy (RA) Al_0.64Ga_0.36N channel MOSHEMTs on sapphire. The RA devices employ a doped n^+-85%-Al barrier and a highly doped n^++-Al_0.86→0.20Ga_0.14→0.80N reverse-graded layer (RGL) for surface ohmic contact formation, whereas the DA devices employ a binary AlN barrier and selectively regrown n^++-GaN source/drain contacts. At 800 ^∘C, the DA channel devices exhibit better thermal stability: their saturated drain current decreases from 460 to 172 mA/mm (62.6%) compared with 338 to 98 mA/mm (71.0%) for the RA channel, and a lower subthreshold swing (459 for DA versus 550 mV/dec for RA). All tested DA devices also exhibit superior threshold-voltage stability (<± 10% versus >± 19% for RA) and maintain an ON/OFF current ratio >10^4 at 800 ^∘C, compared with ~10^3 for RA, thus establishing the DA channel HEMTs as a promising new platform for high-temperature electronics.
ER -