Microwave performance and structural characterization of MBE-grown AlGaN/GaN HEMTs on low dislocation density GaN substrates
Storm, D. F., Katzer, D. S., Roussos, J. A., Mittereder, J. A., Bass, R., Binari, S. C., ... Evans, K. R. (2007). Microwave performance and structural characterization of MBE-grown AlGaN/GaN HEMTs on low dislocation density GaN substrates. Journal of Crystal Growth, 305(2), 340-345. DOI: 10.1016/j.jcrysgro.2007.04.003
We report on the structural and electrical properties of AlGaN/GaN heterostructures grown by molecular beam epitaxy on low-dislocation-density, free standing GaN substrates grown by hydride vapor phase epitaxy. Structural characterization by atomic force microscopy, transmission electron microscopy, and X-ray diffractometry reveal a smooth surface morphology, coherent interfaces, an absence of dislocations generated in the epitaxial layers, and narrow X-ray peaks. Hall measurements indicate room temperature electron mobilities of 1750cm(2)/V s at sheet densities of 1.1X 10(13)Cm(-2). High electron mobility transistors exhibit excellent electrical characteristics, including output power densities of 4.8 W/mm at 10 GHz, off-state breakdown voltages of up to 200 V, and extrinsic cutoff frequencies of 36 GHz on devices with 0.45-mu m gate lengths. (c) 2007 Elsevier B.V. All rights reserved.