This paper reports Al0.27Ga0.73N/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) with stacked Al2O3/HfO2 gate dielectrics by using hydrogen peroxideoxidation/sputtering techniques. The Al2O 3 employed as a gate dielectric and surface passivation layer effectively suppresses the gate leakage current, improves RF drain current collapse and exhibits good thermal stability. Moreover, by stacking the good insulating high-k HfO2 dielectric further suppresses the gate leakage, enhances the dielectric breakdown field and power-added efficiency, and decreases the equivalent oxide thickness. The present MOS-HEMT design has demonstrated superior improvements of 10.1% (16.4%) in the maximum drain-source current (IDS,max), 11.4% (22.5%) in the gate voltage swing and 12.5%/14.4% (21.9%/22.3%) in the two-terminal gate-drain breakdown/turn-on voltages (BVGD/VON), and the present design also demonstrates the lowest gate leakage current and best thermal stability characteristics as compared to two reference MOS-HEMTs with a single Al 2O3/(HfO2) dielectric layer of the same physical thickness.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering