Speaker
Dr
Nobom Hashe
(Nelson Mandela Metropolitan University)
Description
The ternary semiconductor AlxGa1-xAs alloy finds many applications in the electronics industry. With very nearly the same lattice constant as GaAs, it is used as a barrier material in GaAs based heterostructure devices, where the AlGaAs layer confines the electrons to a gallium arsenide region. An example of an AlGaAs/GaAs device is a quantum well infrared photodetector. Alloys are grown on GaAs by metalorganic vapour phase deposition, and different properties of the alloy can be obtained by varying the Al content in AlxGa1-xAs. It is therefore important to characterize the alloy to establish its properties as a function of Al content.
A total of 5 AlxGa1-xAs samples with different Al contents were characterized by Fourier Transform Infrared spectroscopy (FTIR) in the reflectance mode. A Bruker 80V FTIR/Raman system, fitted with a horizontal stage sample holder, enabling near-normal incidence of incident radiation, was used to measure the reflectance of the samples. 50 Scans of each sample were obtained at a resolution of 8 cm-1 and all measurements were done under vacuum. Layer thicknesses could be calculated from interference fringes in the reflectance spectra of the various samples. The results thus obtained by FTIR were compared to scanning electron microscopy (SEM) analyses. Preliminary results indicated that the layer thicknesses varied between 3.2 and 6.1 micron, which are in agreement with values supplied by the epilayer crystal growers. Results will be presented and discussed.
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
N/A
Apply to be<br> considered for a student <br> award (Yes / No)?
No
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Primary author
Dr
Nobom Hashe
(Nelson Mandela Metropolitan University)
Co-authors
Mr
Ettienne Minnaar
(Nelson Mandela Metropolitan University)
Mr
William Goosen
(Nelson Mandela Metropolitan University)
