As-grown deep-level defects in n-GaN grown by metal-organic chemical vapor deposition on freestanding GaN

Journal Article · Sat Sep 01 00:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4748170· OSTI ID:22089424

Shang, Chen; Ishikawa, Kenji; Hori, Masaru ^[1]; Honda, Unhi; Shibata, Tatsunari; Matsumura, Toshiya; Tokuda, Yutaka ^[2]; Ueda, Hiroyuki; Uesugi, Tsutomu; Kachi, Tetsu ^[3]

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1. Nagoya University, Chikusa, Nagoya 464-8603 (Japan)
2. Aichi Institute of Technology, Yakusa, Toyota 470-0392 (Japan)
3. Toyota Central R and D Laboratories, Inc., Yokomichi, Nagakute 480-1192 (Japan)

Traps of energy levels E{sub c}-0.26 and E{sub c}-0.61 eV have been identified as as-grown traps in n-GaN grown by metal-organic chemical vapor deposition by using deep level transient spectroscopy of the Schottky contacts fabricated by resistive evaporation. The additional traps of E{sub c}-0.13 and E{sub c}-0.65 eV have been observed in samples whose contacts are deposited by electron-beam evaporation. An increase in concentration of the E{sub c}-0.13 and E{sub c}-0.65 eV traps when approaching the interface between the contact and the GaN film supports our argument that these traps are induced by electron-beam irradiation. Conversely, the depth profiles of as-grown traps show different profiles between several samples with increased or uniform distribution in the near surface below 50 nm. Similar profiles are observed in GaN grown on a sapphire substrate. We conclude that the growth process causes these large concentrations of as-grown traps in the near-surface region. It is speculated that the finishing step in the growth process should be an essential issue in the investigation of the surface state of GaN.

• OSTI ID: 22089424
• Journal Information: Journal of Applied Physics, Vol. 112, Issue 5; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTIVATION ENERGY
CHEMICAL VAPOR DEPOSITION
CRYSTAL DEFECTS
DEEP LEVEL TRANSIENT SPECTROSCOPY
DISTRIBUTION
ELECTRON BEAMS
ENERGY LEVELS
EVAPORATION
GALLIUM NITRIDES
INTERFACES
IRRADIATION
ORGANOMETALLIC COMPOUNDS
SAPPHIRE
SEMICONDUCTOR MATERIALS
SURFACES
THIN FILMS
TRAPS
VACUUM COATING