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Title: Defect accumulation during channeled erbium implantation into GaN

Abstract

Gallium nitride films epitaxially grown on sapphire, were irradiated at room temperature with 80 keV {sup 166}Er{sup +} or 170 keV {sup 166}Er{sup 2+} ions to fluences ranging from 1x10{sup 13} cm{sup -2} to 1x10{sup 15} cm{sup -2}. The defects induced by ion implantation (as a result of the nuclear energy transfer) generate a perpendicular elastic strain in the hexagonal GaN lattice. The accumulation of lattice damage and lattice deformation were investigated for Er ions impinging along the GaN<0001> axis, i.e., channeled implantation, and compared to random implantation, i.e., the conventional geometry in which the ion beam is tilted 10 deg. off the GaN c axis. For this purpose, Rutherford backscattering and channeling spectrometry and high-resolution x-ray diffraction were used. The defect concentration and the maximum perpendicular strain exhibit the same increasing trend with the ion fluence. Three regimes can be distinguished for both implantation geometries, for low fluences (corresponding to a value below 1 displacement per atom in case of random implantation), the defect concentration remains low due to an effective dynamic annealing process. In the second fluence regime, the defect concentration rises sharply, which is characteristic for nucleation-limited amorphization and finally, a third regime is found where layer-by-layermore » amorphization of the implanted area starts from the surface. The onset of the steep increase in the case of implantations along the GaN c axis is found at a significantly higher erbium fluence compared to random implantation.« less

Authors:
; ;  [1]
  1. Instituut voor Kern-en Stralingsfysica, K. U. Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium)
Publication Date:
OSTI Identifier:
20787718
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 98; Journal Issue: 12; Other Information: DOI: 10.1063/1.2143120; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AMORPHOUS STATE; ANNEALING; ATOMIC DISPLACEMENTS; CRYSTAL DEFECTS; EPITAXY; ERBIUM 166; ERBIUM IONS; GALLIUM NITRIDES; GEOMETRY; ION BEAMS; ION IMPLANTATION; KEV RANGE 100-1000; LAYERS; NUCLEATION; RANDOMNESS; RUTHERFORD BACKSCATTERING SPECTROSCOPY; SAPPHIRE; SEMICONDUCTOR MATERIALS; TEMPERATURE RANGE 0273-0400 K; X-RAY DIFFRACTION

Citation Formats

Pipeleers, Bert, Hogg, Susan M., and Vantomme, Andre. Defect accumulation during channeled erbium implantation into GaN. United States: N. p., 2005. Web. doi:10.1063/1.2143120.
Pipeleers, Bert, Hogg, Susan M., & Vantomme, Andre. Defect accumulation during channeled erbium implantation into GaN. United States. doi:10.1063/1.2143120.
Pipeleers, Bert, Hogg, Susan M., and Vantomme, Andre. Thu . "Defect accumulation during channeled erbium implantation into GaN". United States. doi:10.1063/1.2143120.
@article{osti_20787718,
title = {Defect accumulation during channeled erbium implantation into GaN},
author = {Pipeleers, Bert and Hogg, Susan M. and Vantomme, Andre},
abstractNote = {Gallium nitride films epitaxially grown on sapphire, were irradiated at room temperature with 80 keV {sup 166}Er{sup +} or 170 keV {sup 166}Er{sup 2+} ions to fluences ranging from 1x10{sup 13} cm{sup -2} to 1x10{sup 15} cm{sup -2}. The defects induced by ion implantation (as a result of the nuclear energy transfer) generate a perpendicular elastic strain in the hexagonal GaN lattice. The accumulation of lattice damage and lattice deformation were investigated for Er ions impinging along the GaN<0001> axis, i.e., channeled implantation, and compared to random implantation, i.e., the conventional geometry in which the ion beam is tilted 10 deg. off the GaN c axis. For this purpose, Rutherford backscattering and channeling spectrometry and high-resolution x-ray diffraction were used. The defect concentration and the maximum perpendicular strain exhibit the same increasing trend with the ion fluence. Three regimes can be distinguished for both implantation geometries, for low fluences (corresponding to a value below 1 displacement per atom in case of random implantation), the defect concentration remains low due to an effective dynamic annealing process. In the second fluence regime, the defect concentration rises sharply, which is characteristic for nucleation-limited amorphization and finally, a third regime is found where layer-by-layer amorphization of the implanted area starts from the surface. The onset of the steep increase in the case of implantations along the GaN c axis is found at a significantly higher erbium fluence compared to random implantation.},
doi = {10.1063/1.2143120},
journal = {Journal of Applied Physics},
number = 12,
volume = 98,
place = {United States},
year = {Thu Dec 15 00:00:00 EST 2005},
month = {Thu Dec 15 00:00:00 EST 2005}
}
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