Pulsed laser annealing of Be-implanted GaN

Journal Article · Tue Nov 01 04:00:00 EST 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2120893· OSTI ID:20719672

Wang, H T; Tan, L S; Chor, E F ^[1]

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1. Centre for Optoelectronics, Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

Postimplantation thermal processing of Be in molecular-beam-epitaxy-grown GaN by rapid thermal annealing (RTA) and pulsed laser annealing (PLA) was investigated. It has been found that the activation of Be dopants and the repair of implantation-induced defects in GaN films cannot be achieved efficiently by conventional RTA alone. On the other hand, good dopant activation and surface morphology and quality were obtained when the Be-implanted GaN film was annealed by PLA with a 248 nm KrF excimer laser. However, observations of off-resonant micro-Raman and high-resolution x-ray-diffraction spectra indicated that crystal defects and strain resulting from Be implantation were still existent after PLA, which probably degraded the carrier mobility and limited the activation efficiency to some extent. This can be attributed to the shallow penetration depth of the 248 nm laser in GaN, which only repaired the crystal defects in a thin near-surface layer, while the deeper defects were not annealed out well. This situation was significantly improved when the Be-implanted GaN was subjected to a combined process of PLA followed by RTA, which produced good activation of the dopants, good surface morphology, and repaired bulk and surface defects well.

• OSTI ID: 20719672
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 98; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
BERYLLIUM IONS
CARRIER MOBILITY
CRYSTAL DEFECTS
DOPED MATERIALS
GALLIUM NITRIDES
ION IMPLANTATION
KRYPTON FLUORIDE LASERS
LAYERS
MOLECULAR BEAM EPITAXY
MORPHOLOGY
PENETRATION DEPTH
RAMAN SPECTRA
SEMICONDUCTOR MATERIALS
STRAINS
STRESSES
SURFACES
THIN FILMS
X-RAY DIFFRACTION