Abstract
Al2O3-passivated Schottky-gate AlGaN/GaN high electron mobility transistors (HEMTs) with improved subthreshold swing (SS) and drain current ON/OFF ratio by postmetallization annealing (PMA) at 500 °C in N2 ambient are reported. With the PMA, the gate leakage current in the reverse biased region and the OFF-state drain current are reduced by more than three orders of magnitude, leading to a low SS of 84.75 mV/dec and a high drain current ON/ OFF ratio of 2.1\times 10^{7}. Through temperature-dependent current-voltage measurements on dual-Schottky-gate structures and capacitance-voltage measurements on Al2O3/AlGaN/GaN metal-insulator-semiconductor (MIS) HEMT capacitors, it is identified that the PMA greatly suppresses both the Al2O3/AlGaN interface leakage current and the reverse gate leakage current by eliminating Al2O3/AlGaN interface trap states with 0.34 eV trap state energy and changing the dominant mechanism of reverse gate leakage conduction from trap-assisted tunneling to Fowler-Nordheim tunneling, respectively. Overall, this work reports on the effectiveness of PMA in improving the performance of Schottky-gate AlGaN/GaN HEMTs and the underlying improving mechanisms.
Original language | English (US) |
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Article number | 9094302 |
Pages (from-to) | 2760-2764 |
Number of pages | 5 |
Journal | IEEE Transactions on Electron Devices |
Volume | 67 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2020 |
Keywords
- AlGaN
- GaN
- drain current ON/OFF ratio
- high electron mobility transistor (HEMT)
- leakage
- postmetallization annealing (PMA)
- subthreshold swing (SS)
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering