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Title: Enhanced damage buildup in C{sup +}-implanted GaN film studied by a monoenergetic positron beam

Wurtzite GaN films grown by hydride vapor phase epitaxy were implanted with 280 keV C{sup +} ions to a dose of 6 × 10{sup 16 }cm{sup −2}. Vacancy-type defects in C{sup +}-implanted GaN were probed using a slow positron beam. The increase of Doppler broadening S parameter to a high value of 1.08–1.09 after implantation indicates introduction of very large vacancy clusters. Post-implantation annealing at temperatures up to 800 °C makes these vacancy clusters to agglomerate into microvoids. The vacancy clusters or microvoids show high thermal stability, and they are only partially removed after annealing up to 1000 °C. The other measurements such as X-ray diffraction, Raman scattering and Photoluminescence all indicate severe damage and even disordered structure induced by C{sup +}-implantation. The disordered lattice shows a partial recovery after annealing above 800 °C. Amorphous regions are observed by high resolution transmission electron microscopy measurement, which directly confirms that amorphization is induced by C{sup +}-implantation. The disordered GaN lattice is possibly due to special feature of carbon impurities, which enhance the damage buildup during implantation.
Authors:
; ;  [1] ; ;  [2]
  1. Department of Physics, Hubei Nuclear Solid Physics Key Laboratory, Wuhan University, Wuhan 430072 (China)
  2. Advanced Science Research Center, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)
Publication Date:
OSTI Identifier:
22413194
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMORPHOUS STATE; ANNEALING; CARBON IONS; DOPPLER BROADENING; EMISSION SPECTRA; FILMS; GALLIUM NITRIDES; HYDRIDES; PHASE STABILITY; PHOTOLUMINESCENCE; POSITRON BEAMS; RAMAN SPECTROSCOPY; TRANSMISSION ELECTRON MICROSCOPY; VACANCIES; VAPOR PHASE EPITAXY; X-RAY DIFFRACTION