<p> Periodic arrays of Au patterns (dots and lines) were produced via electron beam
lithography (EBL). GaAs mesas were produced by using the Au structures as a mask and
wet etching the GaAs (lll)B substrates, leaving Au resting above GaAs pillars.
Annealing experiments at typical nanowire growth temperatures (550°C) were performed
on both mesa-supported samples and a control sample without mesas, and were later
characterized by scanning electron microscopy (SEM). From SEM images, a model is
proposed to describe the evolution of the Au seed particle during exposure to typical
growth conditions. The Au particle is subject to not only a melting process but is also
modified by a volume increase due to incorporating Ga atoms and a subsequent crystal
structure change. Palpable discrepancies between the mesa-supported and control
samples were observed after annealing experiments, suggesting the mesas were effective
in confining the migration of the Au. NW s were then grown via gas source molecular
beam epitaxy (GS-MBE). Discemable variation amongst the results was evident when a
comparison between annealed samples and the grown counterpart was made. The
inconsistency is ascribed to the NW growth process beginning only after supersaturation
at the growth interface. This saturation took place only after 2-D film growth on the
substrate surpassed the height of the mesas rendering the structures less functional. </p> / Thesis / Master of Applied Science (MASc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/21793 |
| Date | 01 1900 |
| Creators | Roumeliotis, Michael |
| Contributors | LaPierre, R. R., Engineering Physics |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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