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Title: Annealing behaviors of vacancy-type defects near interfaces between metal contacts and GaN probed using a monoenergetic positron beam

Vacancy-type defects near interfaces between metal contacts and GaN grown on Si substrates by metal organic chemical vapor deposition have been studied using a monoenergetic positron beam. Measurements of Doppler broadening spectra of the annihilation radiation for Ti-deposited GaN showed that optically active vacancy-type defects were introduced below the Ti/GaN interface after annealing at 800 °C. Charge transition of those defects due to electron capture was observed and was found to correlate with a yellow band in the photoluminescence spectrum. The major defect species was identified as vacancy clusters such as three to five Ga-vacancies coupled with multiple nitrogen-vacancies. The annealing behaviors of vacancy-type defects in Ti-, Ni-, and Pt-deposited GaN were also examined.
Authors:
;  [1] ; ; ;  [2] ;  [3] ;  [4] ; ;  [5]
  1. Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)
  2. Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States)
  3. Nanosystem Research Institute “RICS,” National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)
  4. Wide Bandgap Material Group, National Institute for Materials Science, Tsukuba 305-0044 (Japan)
  5. IQE, 200 John Hancock Road, Taunton, Massachusetts 01581 (United States)
Publication Date:
OSTI Identifier:
22314492
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANNEALING; CHEMICAL VAPOR DEPOSITION; DEFECTS; GALLIUM NITRIDES; NITROGEN; ORGANOMETALLIC COMPOUNDS; PHOTOLUMINESCENCE; PLATINUM; POSITRON BEAMS; TITANIUM; VACANCIES