Dispersive Effects in Microwave AlGaN/AlN/GaN HEMTs With Carbon-Doped Buffer
Journal article, 2015

Aluminium gallium nitride (AlGaN)/GaN high-electron mobility transistor performance is to a large extent affected by the buffer design, which, in this paper, is varied using different levels of carbon incorporation. Three epitaxial structures have been fabricated: 1) two with uniform carbon doping profile but different carbon concentration and 2) one with a stepped doping profile. The epitaxial structures have been grown on 4H-SiC using hot-wall metal-organic chemical vapor deposition with residual carbon doping. The leakage currents in OFF-state at 10 V drain voltage were in the same order of magnitude (10(-4) A/mm) for the high-doped and stepped-doped buffer. The high-doped material had a current collapse (CC) of 78.8% compared with 16.1% for the stepped-doped material under dynamic I-V conditions. The low-doped material had low CC (5.2%) but poor buffer isolation. Trap characterization revealed that the high-doped material had two trap levels at 0.15 and 0.59 eV, and the low-doped material had one trap level at 0.59 eV.

Current collapse (CC)

trap levels

gallium nitride (GaN)

high-electron mobility transistor (HEMT)

dispersion

Author

Sebastian Gustafsson

GigaHertz Centre

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

J. T. Chen

Johan Bergsten

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Urban Forsberg

Mattias Thorsell

GigaHertz Centre

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

E. Janzen

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

IEEE Transactions on Electron Devices

0018-9383 (ISSN)

Vol. 62 7 2162-2169

Areas of Advance

Information and Communication Technology

Subject Categories

Subatomic Physics

Nano Technology

DOI

10.1109/ted.2015.2428613

More information

Created

10/7/2017