Abstract
Diamond is nowadays regarded as a potential semiconductor material of the
future, due to its extreme and unique properties. Some of these properties, in-
clude its high hardness, highest breakdown ¯eld, high Debye temperature, high
thermal conductivity, high hole and electron mobilities, large bandgap and op-
tical transparency, among others. These properties make diamond suitable for
high-temperature, high-speed and high-power electronic applicatons, as well as
in other applications. However, defects associated with ion implantation have
been shown to make it rather di±cult to obtain n-type doping in diamond. As
such, an understanding of the nature of defects produced during ion implanta-
tion of diamond remains a subject of great importance, if not essential, for the
optimization of high-temperature, high-power electronic applications in partic-
ular. In this respect, this study investigates the nature of the radiation damage
generated within the collision cascades of multi-implantations of carbon ions
in high-pressure, high-temperature single-crystal synthetic type Ib diamond,
spread over a range of energies (50-150keV) and doses. This is achieved by
means of the cold-implantation-rapid-annealing (CIRA) routine, and the anal-
ysis of damage caused was done by using cross sectional transmission electron
microscopy techniques. More precisely, the modes used to achieve this are the
bright ¯eld transmission electron microscopy (BFTEM) coupled with selected
area di®raction or SAD.
At low dose implantation or at sub-critical implantation doses (2.5x1015
ions/cm2), it was found that the ion-damaged diamond layer consists of some
threading dislocations, not homogeneously distributed which propagate from
the surface into the ion-damaged diamond.
In contrast to the sub-critical implantation doses , it was found that at very
high implantation doses (7.0x1015 ions/cm2), i.e., above the critical dose (where diamond transforms to graphite upon annealing), the damaged diamond layer
had some unconventional defect features close to the implanted surface.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/4539 |
| Date | 06 March 2008 |
| Creators | Nshingabigwi, Emmanuel Korawinga |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 5451483 bytes, application/pdf, application/pdf |
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