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School of Physical, Environmental and Mathematical Sciences |
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Field of Study - Advanced Materials
Supervisor: Dr Heiko Timmers (PEMS)
Co-Supervisor: Assoc. Prof. Don H. Chaplin (Visiting Fellow, PEMS)
Research Topic - Characterisation of Indium Nitride with Swift Ions and Radioisotope Probes
Summary of Work
Charaterisation of indium nitride with swift ions and radioisotope probes
Indium nitride (InN) has potential for application in high-speed and high-power transistors. However, quality material of this type is still under development and material properties such as film stoichiometry and the role of impurity elements are not well understood. Moreover, fundamental properties of the material like the electronic band gap are being debated.
The stoichiometry of InN films grown with different techniques has been measured with heavy ion elastic recoil detection analysis. Severe nitrogen depletion, observed during analysis with 1 MeV/A197Au and 109Ag beams, has been fitted with a bulk molecular recombination model to obtain the original nitrogen-to-indium ratio. Interestingly, recent experimental results show that the use of low-Z beams such as 32S and 19F, does not result in such nitrogen depletion, thus enabling the efficient compositional analysis of the material without theoretical modelling.
The Radioisotope Implanter at UNSW@ADFA has been developed to the stage that the standard radioisotope probe 111In/Cd can routinely be introduced into materials as 111InO - ions with micro-curie activities. Experiments with variety of materials have shown that radiotracer studies with perturbed angular correlation, nuclear magnetic resonance on oriented nuclei and nuclear orientation can reliably be performed.
Refereed publications
S.K. Shrestha , H. Timmers, A.P. Byrne, W.D. Hutchison, D.H. Chaplin, R. Dogra, Implantation of the 111In/Cd probe as InO - ion for radioisotope tracer studies , accepted for publication by the Hyperfine Interactions (2004).
S.K. Shrestha, K.S.A. Scott Butcher, M. Wintrebert-Fouquet, H. Timmers, Reliable ERD analysis of group-III nitrides despite severe nitrogen depletion, Nuclear Instruments and Methods B, 219-220 (2004), 686-692.
S.K. Shrestha , H. Timmers, K.S.A. Scott Butcher, M. Wintrebert-Fouquet, Accurate Stoichiometric Analysis of Polycrystalline Indium Nitride Films with Elastic Recoil Detection, Current Applied Physics, 4 (2004), 237-240.
H. Timmers, S.K. Shrestha , A.P. Byrne, The potential of ion beam techniques for the development of indium nitride, Journal of Crystal Growth, 269 (2004), 50-58.
K.S.A. Butcher, M. Wintrebert-Fouquet, P. P.-T. Chen, H. Timmers, S.K. Shrestha , Detailed Analysis of Absorption Data for Indium Nitride, Materials Science in Semiconductor Processing, 6 (2003), 351-354.
K.S.A. Butcher, M. Wintrebert-Fouquet, P. P.-T. Chen, T.L. Tansley, H. Dou, S.K. Shrestha , H. Timmers, M. Kuball , K.E. Prince, J.E. Bradby, Nitrogen-Rich Indium Nitride , Journal of Applied Physics, 95 (2004), 6124-6128.
K.S.A. Butcher, M. Wintrebert-Fouquet, P.P.-T. Chen, K.E. Prince, H. Timmers, S.K. Shrestha , T.V. Shubina, S.V. Ivanov, R. Wuhrer, M.R. Phillips and B. Monemar, Non-stoichiometry and Non-homogeneity in InN , submitted to phys. stat. sol. (2004).
Conference contributions
S.K. Shrestha , H. Timmers, A.P. Byrne, D.H. Chaplin, A.V.J. Edge, W.D. Hutchison, First radioisotope implantation with a new facility at the Australian Defence Force Academy , Proceedings of the 13th Australian Conference on Nuclear Techniques of Analysis, ISBN 0-9577217-9-X, 26-28 November 2003, Lucas Heights, Australia.
S.K. Shrestha , A.P. Byrne, D.H. Chaplin, A.V.J. Edge, W.D. Hutchison, H. Timmers, Radioisotope Implantation with a new facility at the Australian Defence Force Academy , Proceedings of the 5 th conference on Nuclear science & Engineering in Australia, ISBN 0-949188-14-X, 5-6 November 2003, Canberra, Australia.
S.K. Shrestha , D.J. Smith, H. Timmers, A.P. Byrne, D.H. Chaplin, W.D. Hutchison, J.X. Wei, A Low Energy Radioactive Ion Implanter for Materials Studies , Proceedings of the 27 th Australian and New Zealand Condensed Matter and Materials Meeting, 4-7 February 2003, Wagga Wagga, Australia.
D. J. Smith, S.K. Shrestha , H. Timmers, D.H. Chaplin, A.P. Byrne, W.D. Hutchison, Commissioning the 150 KeV Radioactive Ion Implanted for Materials Studies , 15th Biennial Australian Institute of Physics Congress, 8-11 July 2002, Sydney, Australia.
K. S. A. Butcher, M. Wintrebert-Fouquet, P. P.-T. Chen, T. L. Tansley, S. Srikeaw, S. Shrestha , R. G. Elliman and H. Timmers, Indium Nitride Emerges , Proceedings of the Australian Institute of Physics Biennial Congress 2002, Sydney, Australia, published by Causal Productions, ISBN 0-9598064-4-X.