Browsing by Author "Tansley, TL"

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    Elemental composition of reactively sputtered indium nitride thin films
    (The Japan Society of Applied Physics, 1996-04-15) Sunil, K; Mo, L; Motlan; Tansley, TL
    Indium nitride (InN) thin films have been grown on a variety of substrates using low-temperature radio frequency reactive sputtering of indium metal in pure nitrogen plasma. Quantitative compositional analyses of the films, carried out using X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectrometry (RBS), suggest that large amounts of oxygen are present in them. The high concentration of oxygen in our films is attributed to the voided microstructure as revealed by cross-sectional scanning electron microscopy. The XPS studies also suggest that the oxygen incorporated into the films is bonded to nitrogen. © 1996, The Japan Society of Applied Physics
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    Growth of high purity liquid phase epitaxial GaAs in a silica growth system
    (Elsevier, 1995-12-01) Butcher, KSA; Mo, L; Alexiev, D; Tansley, TL
    Liquid phase epitaxial gallium arsenide layers, greater than 200 μm thickness and with a low net carrier concentration (NA,D ≈ 1013 cm−3) have been grown in a silicia growth system with silica crucibles. Analysis of electrical and chemical defects was carried out using capacitance-voltage (C---V) measurements, deep level transient spectroscopy (DLTS) and secondary ion mass spectroscopy (SIMS). Details of the growth procedure are given and it is shown that silicon incorporation in the growth layer is not suppressed by the addition of ppm levels of oxygen to the main hydrogen flow. © 1995, Elsevier Ltd.
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    The measurement of minority carrier diffusion lengths for high purity GaAs using an electron beam induced current technique
    (Australian Nuclear Science and Technology Organisation, 1990-07) Butcher, KSA; Alexiev, D; Tansley, TL; Leung, S
    Measurements of minority carrier diffusion lengths for p-type and n-type GaAs were carried out using an electron beam induced current technique. The GaAs material was grown by liquid phase epitaxy at the Australian Nuclear Science and Technology Organisation. The diffusion lengths measured for the n-type materials show good agreement with past results for material of similar purity. For higher purity p-type and n-type samples diffusion lengths were observed which are larger than any previously reported. For different electron beam voltages the observed values of diffusion length were unaffected by surface recombination. This again indicates very pure material. The diffusion length measurements reported here indicate that the LPE GaAs samples being produced by the Australian Nuclear Science and Technology Organisation's Radiation Detectors Project are of the highest quality for producing X-rays and low energy gamma ray radiation detectors.
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    Variations in the apparent optical band-gap of RPE-CVD grown indium nitride thin films
    (Australian Institute of Physics, 2004-02-05) Butcher, KSA; Wintrebert-Fouquet, M; Chen, PPT; Tansley, TL; Prince, KE
    Indium nitride is a semiconducting material with a band-gap which is in current dispute. Although a ~ 0.75 eV band-gap was announced by some international groups in 2002 [1,2], it has since been shown that all the evidence for a ~ 0.75 eV band-gap is due to deep level defects [3, 4]. Despite this there still appears to be anomolous variations in the apparent bandgap for this material. The Macquarie University Low Temperature Nitride Film Growth Facility has recently grown some very high quality indium nitride thin films by remote plasma enhanced chemical vapour deposition (RPE-CVD). This material shows a variation in the apparent band-gap, as measured by optical absorption techniques, of 1.2 eV to 1.8 eV, dependent on the growth temperature and time. SIMS results measured by the ANSTO SIMS group show that the oxygen content of the films is low and that the variation in the apparent band-gap is not correlated to oxygen content. Other film properties will be described.