from 28 June 2015 to 3 July 2015 (Africa/Johannesburg)
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SAIP2015 Proceeding published on 17 July 2016
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High resolution X-ray diffraction and photoluminescence of InAs1-xSbx/GaSb

Presented by Mr. Stephen DOBSON on 30 Jun 2015 from 16:10 to 18:00
Type: Poster Presentation
Session: Poster1
Track: Track A - Division for Physics of Condensed Matter and Materials
Board #: A.283


InAs<sub>1-x</sub>Sb<sub>x</sub> has the lowest energy band gap among all the III-V semiconductors and has thus received a great deal of attention as an important material to be incorporated into infrared optoelectronic devices. Photodetectors containing this ternary have potential to reach wavelengths up to 9 µm. To achieve this, high quality thin films with few defects and impurities are required. One of the key issues in using InAs<sub>1-x</sub>Sb<sub>x</sub> in the device architecture (particularly for wavelengths greater than 4 µm) is the lack of available lattice-matched substrates. To date, the best performing InAsSb-containing devices are lattice matched to GaSb substrates, with a 9% antimony solid content. (i.e. InAs<sub>0.91</sub>Sb<sub>0.09</sub>). This paper focuses on the deposition of high quality thin films of InAs<sub>0.91</sub>Sb<sub>0.09</sub> (between 2 µm and 4 µm thick) on 2″ GaSb substrate. The material deposition is performed in a metal organic chemical vapour deposition (MOCVD) system. The process begins by the deposition of a thin (nanometer thickness range) low temperature buffer layer of either GaSb followed by the deposition of strain free InAsSb. High resolution X-ray diffraction (HRXRD) is used to precisely determine the composition of the ternary alloy as well as to investigate the uniformity across the entire wafer. Photoluminescence (PL), using a Fourier-transform infrared (FTIR) spectrometer, is employed to further explore the material quality and purity. Preliminary measurements indicate consistent thickness and compositional uniformity of the InAsSb layers.






Prof JR Botha NMMU





Primary authors