Al0.26Ga0.74N/GaN metal-oxide-semiconductor heterostructure field-effect transistors (MOS-HFETs) grown on a Si substrate with Al2O3/TiO2 stacked gate dielectrics formed by using non-vacuum ultrasonic spray pyrolysis deposition (USPD) technique are investigated. High permittivity (k) values of Al2O3 and TiO2 were characterized to be 9 and 46.1, respectively, with an equal layer thickness of 10 nm. The present MOS-HFET (Schottky-gate HFET) design has demonstrated enhanced device characteristics at 300 K, including maximum drain-source current density (I DS,max) of 725 (530) mA/mm, I DS at V GS = 0 V (I DSS0) of 471 (383) mA/mm, gate-voltage swing (GVS) of 2.5 (1.6) V, two-terminal gate-drain breakdown voltage (BV GD) of -182 (-121) V, turn-on voltage (V on) of 4.9 (3.2) V, three-terminal off-state drain-source breakdown voltage (BV DS) of 174 (103) V, on/off current ratio (I on/I off) of 5.6 ×107 (3.7 ×103), unity-gain cut-off frequency (f T) of 10.3 (6.8) GHz, maximum oscillation frequency (f max) of 14.8 (8.6) GHz, and power-added efficiency (P.A.E.) of 38.5% (31.7%) at 2.4 GHz. High temperature device characteristics up to 450 K are also discussed.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry