A GaN-SiC hybrid material for high-frequency and power electronics
Journal article, 2018

We demonstrate that 3.5% in-plane lattice mismatch between GaN (0001) epitaxial layers and SiC (0001) substrates can be accommodated without triggering extended defects over large areas using a grain-boundary-free AlN nucleation layer (NL). Defect formation in the initial epitaxial growth phase is thus significantly alleviated, confirmed by various characterization techniques. As a result, a high-quality 0.2-μm thin GaN layer can be grown on the AlN NL and directly serve as a channel layer in power devices, like high electron mobility transistors (HEMTs). The channel electrons exhibit a state-of-the-art mobility of >2000 cm2/V-s, in the AlGaN/GaN heterostructures without a conventional thick C- or Fe-doped buffer layer. The highly scaled transistor processed on the heterostructure with a nearly perfect GaN-SiC interface shows excellent DC and microwave performances. A peak RF power density of 5.8 W/mm was obtained at VDSQ= 40 V and a fundamental frequency of 30 GHz. Moreover, an unpassivated 0.2-μm GaN/AlN/SiC stack shows lateral and vertical breakdowns at 1.5 kV. Perfecting the GaN-SiC interface enables a GaN-SiC hybrid material that combines the high-electron-velocity thin GaN with the high-breakdown bulk SiC, which promises further advances in a wide spectrum of high-frequency and power electronics.

Author

J. T. Chen

SweGaN AB

Johan Bergsten

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Jun Lu

Linköping University

E. Janzen

SweGaN AB

Mattias Thorsell

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics, Microwave Electronics

L. Hultman

Linköping University

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics, Microwave Electronics

O. Kordina

SweGaN AB

Applied Physics Letters

0003-6951 (ISSN) 1077-3118 (eISSN)

Vol. 113 4 041605

Subject Categories

Materials Chemistry

Other Materials Engineering

Condensed Matter Physics

DOI

10.1063/1.5042049

More information

Latest update

8/8/2018 2