Al(In)GaN/(In)GaN High Electron Mobility Transistors for Low-Noise and High-Power Applications

AlInGaN-based heterostructures have demonstrated unmatched versatility in optical and electronic applications. In particular, AlGaN/GaN high electron mobility transistors (HEMTs) are the leading candidates for realizing ultra-high frequency, low-noiseand high-power amplifiers. The addition of indium to the composition of these HEMTs is expected to dramatically improve their performance. We propose a comprehensive program to study the growth of Al(In)GaN/(In)GaN heterostructures on sapphire and SiCsubstrates using molecular beam epitaxy (MBE). The MBE technique is uniquely suited for the synthesis of In-containing compounds due to the growth mechanisms and the lower temperatures required in comparison to MOCVD. Our program will include detailedinvestigations on the processing of AlInGaN materials and the fabrication of high performance HEMTs. The effect of In on the interface quality and its impact on electron transport will be characterized extensively using microanalytical and electricaltechniques. Concurrently, we will investigate methods of etching, and study ohmic and Schottky contact formation. We will then integrate these results to fabricate and characterize (DC, RF, power, and noise properties) Al(In)GaN/(In)GaN HEMTs. Someprojected device parameters to achieve are current density > 1.2A/mm, extrinsic transconductance value > 400 mS/mm, fT > 200 GHz, and power density > 8 W/mm at 40 GHz.Improved AlInGaN-based heterostructure transistors would result from this Phase I effort.These transistors will have unmatched versatility in optical and electronic applications. End applications of these ulta-high frequency, low-noise and high-power transistors include radar tracking, cellular base stations, telemetry, and satellitecommunications.