Electrical properties and deep traps spectra in undoped and Si-doped m-plane GaN films

Autor: Hiroshi Amano, K. D. Scherbatchev, Alexander Y. Polyakov, A. V. Markov, T. G. Yugova, N. B. Smirnov, Takeshi Kawashima, V. T. Bublik, A. V. Govorkov, E. A. Petrova
Rok vydání: 2009
Předmět:
Zdroj: Journal of Applied Physics. 105:063708
ISSN: 1089-7550
0021-8979
DOI: 10.1063/1.3078769
Popis: Structural and electrical properties of nonpolar m-GaN films grown on m-SiC using standard metalorganic chemical vapor deposition (MOCVD) and two versions of sidewall epitaxial lateral overgrowth were studied. It is shown that lateral overgrowth allows one to dramatically reduce the dislocation density from over 109 cm−2 to ∼107 cm−2. In good correlation with that we observed a strong reduction in the density of electron traps Ec−0.25 eV and Ec−0.6 eV from over 1015 cm−3 to ∼1014 cm−3, respectively, in MOCVD m-GaN and in laterally overgrown m-GaN. Preliminary studies of the effects of changing the V/III ratio and of Si doping were performed. The MOCVD m-GaN films grown with high V/III ratio of 1000 were semi-insulating, with the Fermi level pinned near the 0.6 eV traps. Decreasing the V/III value to 250 shifted the Fermi level upward, close to the level of the 0.25 eV traps. Si doping in laterally overgrown samples strongly suppressed the formation of major electron traps but enhanced the formation of hol...
Databáze: OpenAIRE