Review of Recent Developments in Growth of AlGaN/GaN High-Electron Mobility Transistors on 4H-SiC by Plasma-Assisted Molecular Beam Epitaxy

Andrea CORRION  Christiane POBLENZ  Patrick WALTEREIT  Tomas PALACIOS  Siddharth RAJAN  Umesh K. MISHRA  Jim S. SPECK  

IEICE TRANSACTIONS on Electronics   Vol.E89-C    No.7    pp.906-912
Publication Date: 2006/07/01
Online ISSN: 1745-1353
DOI: 10.1093/ietele/e89-c.7.906
Print ISSN: 0916-8516
Type of Manuscript: Special Section INVITED PAPER (Special Section on Heterostructure Microelectronics with TWHM2005)
MBE,  Gallium Nitride,  HEMT,  microwave,  MBE,  

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In this paper we review our recent work developing the growth of AlGaN/GaN high-electron mobility transistors (HEMTs) grown on SiC (0001) by plasma-assisted molecular beam epitaxy (PA-MBE). State-of-the-art AlGaN/GaN HEMTs have been achieved using MBE-grown material. Buffer leakage was an important limiting factor for early devices. We have shown that by appropriately controlling the Al/N flux ratio during growth of the nucleation layer on SiC(0001), low-leakage GaN buffers can be subsequently grown. In addition, a "modulated growth" technique was developed to achieve large area uniformity and surface morphology control. High-performance HEMTs were fabricated utilizing these two techniques. On 200 nm gate-length devices, at 4 GHz an output power density of 8.4 W/mm was obtained with a power-added efficiency (PAE) of 67% at a drain bias of 30 V. At a higher drain bias (42 V), 13.7 W/mm with a PAE of 55% was achieved.