Speaker
Mr
Phuti Ngoepe
(University of Pretoria)
Description
Aluminum gallium nitride (AlxGaxN) is a ternary wide direct bandgap semiconductor. The Al to Ga ratio can be varied to achieve various bandgap ranging from 3.4 eV for pure GaN to 6.2 eV for pure AlN. This property makes AlGaN based devices suitable for light emitting and light detecting devices such as LED’s and photodiodes. In fabricating a device such as a Schottky diode the metals deposited on the semiconductor play an important role in the operation of the device. This is because the metal-semiconductor contact of a Schottky diode influences the transport mechanisms of the device. It therefore becomes significant to understand the interaction of metals with the semiconductor substrate. Annealing has been used as a method of studying the evolution of the optical and electrical properties of semiconductor based devices [1,2]. In particular a study was performed on AlGaN Ni (20 Å)/ Au (50 Å) and Ni (20 Å)/ Ir (30 Å)/ Au (50 Å) Schottky photodiodes [3]. The samples were subjected to isochronous annealing for 5 min. under an Ar. ambient. The evolution of the chemical properties of these contacts with temperature is studied by using two surface characterization methods namely Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS) and X-ray photo electron spectroscopy (XPS).
At what level of studies are you currently? (Hons/MSc/PhD)
PhD
Are you currently a postgraduate student? (Yes/No)
Yes
Please provide the name and email address of your supervisor.
Prof. WE Meyer; wmeyer@up.ac.za
Primary author
Mr
Phuti Ngoepe
(University of Pretoria)
Co-authors
Prof.
Danie Auret
(University of Pretoria)
Dr
Elizabeth Coetsee
(University of the Free State)
Mr
Ezekiel Omotoso
(University of Pretoria, Pretoria, South Africa)
Prof.
Hendrik Swart
(University of the Free State)
Ms
Mart-Mari Duvenhage
(University of the Free State)
Dr
Mmantsae Diale
(University of Pretoria)
Prof.
Walter Meyer
(University of Pretoria)
