0.2-mu m AlGaN/GaN High Electron-Mobility Transistors With Atomic Layer Deposition Al2O3 Passivation

Dong Xu, BAE Systems
Kanin Chu, BAE Systems
Jose Diaz, BAE Systems
Wenhua Zhu, BAE Systems
Richard Roy, BAE Systems
Louis Mt. Pleasant, BAE Systems
Kirby Nichols, BAE Systems
Pane-Chane Chao, BAE Systems
Xianfan Xu, Birck Nanotechnology Center, Purdue University
Peide D. Ye, Birck Nanotechnology Center, Purdue University

Abstract

We report a successful application of atomic layer deposition (ALD) aluminum oxide as a passivation layer to gallium nitride high electron-mobility transistors (HEMTs). This new passivation process results in 8%-10% higher dc maximum drain current and maximum extrinsic transconductance, about one order of magnitude lower drain current in the subthreshold region, 10%-20% higher pulsed-IV drain current, and 27%-30% higher RF power with simultaneously 5-8 percentage point higher power-added efficiency. The achieved improvement in device performance is attributed to the outstanding quality of the interface between III-N and the ALD aluminum oxide resulting from the uniqueness of the adopted ALD process, featuring a wet-chemical-based wafer preparation as well as a pregrowth self-cleaning procedure in the growth chamber. This technology can be readily integrated into the HEMT-based integrated circuit fabrication process, making the ALD aluminum oxide-passivated GaN HEMTs excellent candidates for multiple microwave and millimeter-wave power applications.

Discipline(s)

Nanoscience and Nanotechnology