Thesis (Ph. D.)--University of Glasgow, 2003. / Includes bibliographical references. Print version also available.

Thesis (M.S.)--Eastern Illinois University, 1967. / Vita. Includes bibliographical references (leaves 351-353).

Thesis (M.S.)--Eastern Illinois University, 1976. / Includes bibliographical references (leaves 139-140).

No description available.

This thesis reports the development of two rapid thermal annealing systems, one based on resistive heating of graphite strips, the second on heating from incoherent lamp radiation. Electrical activation studies of silicon implanted gallium arsenide has been used to compare the systems with those available commercially. It has been shown that commercial systems can yield temperature measurement errors in excess of 50° C. Furthermore, the systems have been used to investigate the electrical activation of silicon implants co-implanted with other ions into gallium arsenide, with a view to either, improving the activation of the silicon for high doses, or modifying the carrier profile shape for low doses. A factor of two improvement in the electrical activation of high dose silicon implants has been achieved by the co-implantation of phosphorus, with a reduction in the annealing temperature required to achieve a given activity also being observed. An alternative processing methodology is also proposed for through- nitride implantation. Phosphorus implants have also been used to "pre-amorphise" substrates to prevent ion channelling. Providing the damage is maintained below a certain level, improvements in profile shape can be obtained. Other compensation techniques using boron and carbon implants have also been investigated. Boron has been demonstrated to provide improved carrier activation for low implant doses, with thermally stable profile modification capability as the dose is increased. The electrical activation of single carbon implants (40% maximum) is below the level of compensation of silicon implants (approximately 90%) co-implanted with carbon. This in turn means carbon is excellent for profile modification as no p-type layer is created beyond the donor implant.

Studies have been completed into the spectral response of alkaline and other ultramafic rocks from arid and semi-arid regions. To date these rocks have not been investigated spectrally in a systematic fashion using the latest field and airborne imaging spectrometers. The objective was to determine how spectral geological techniques could be used to locate these rock types when they are exposed, weathered and reduced to residual soil. The data used in this study were spectra obtained from field spectrometers (PIMA and GER IRIS MkIV) and airborne scanners (GEOSCAN MkII, GER IS and HyMap). These data were gathered at four sites within Australia. The data processing software packages used for the analyses were commercially available image processing systems (is S'600and ENVI) and a modified version of PIMAVIEW for processing spectra. Spectra were measured, in the field and the laboratory, of alkaline and other ultramafic rocks to determine if they had diagnostic spectral absorption features. These studies demonstrated that there are diagnostic spectral absorption features common to alkaline and other ultramafic rocks including dunite, peridotite and serpentinite. The diagnostic spectrum in the SWIR2 region (2000nm to 2500nm) has absorption features located near 2300nm and 2380nm and results from Mg-OH bearing minerals including serpentine, talc and phlogopite. The VNIR spectra of these rocks also have distinct absorption features, but since these are caused by minerals that are common to a variety of rocks and soils, they have not been considered in this study. When weathered under arid and semi-arid conditions, ultramafic rocks break down into smectite clays, primarily saponite. Saponite has a similar spectral signature to the primary Mg-OH bearing minerals. Further weathering and removal of magnesium results in saponite altering to kaolinite and then to opaline silica. These minerals may occur in residual soils derived from ultramafic rocks. Spectral investigation of mixtures of saponite and other minerals showed that there are linear changes the absorption features of spectra, depth, wavelength and shape, as the proportion of saponite to other minerals varies. The ability to identify ultramafic rocks from the distribution of their diagnostic spectra was confirmed by analysing data obtained from surface samples and airborne scanners. The coincidence of results obtained from field studies and airborne scanner data signifies that data acquired remotely are as useful as spectra obtained in the field, for mapping the extent of ultramafic rocks. Present and past imaging systems have been investigated to determine the specifications required to suit this application. These investigations included sampling the spectra of ultramafic and background rocks with the band pass characteristics of various instruments. The signal-to-noise ratio that is required of scanner data to ensure it is useable was also studied. These studies indicated a specification for data of at least eight and preferably, thirty two channels in the SWIR2 (between 2000nm and 2500nm) obtained with a signalto-noise ratio in excess of 200: 1, ideally 400: 1 at 2200nm. Scanners producing data with these specifications can be used to locate ultramafic rocks from their spectral signature, whether exposed or covered by residual soils in a variety of geological environments. The success of applying these techniques will however depend on the spectral contrast between ultramafic rocks and their backgrounds. Rocks that produce Mg-OH bearing minerals or have near 2300nm absorption can result in areas being mistakenly identified as containing alkaline and other ultramafic rocks. However, in this study it was demonstrated that carbonate soils and rocks that have a near 2300nm absorption feature can be spectrally distinguished from alkaline ultramafic derived saponite using HyMap scanner data. In South Australia dolomite appears to have altered to saponite at surface but kimberlites in the area can still be detected by processing HyMap scanner data with spectral as opposed to conventional image processing techniques.

The incorporation of Si1-xGex alloy heterostructures into conventional Si processes has been proposed as a means of improving the operating frequency and overall performance of Si field effect transistors. One parameter expected to benefit from this approach is the hole mobility, which would have important implications for high speed CMOS applications. Measured values of the hole mobility, however, have failed to live up to early expectations, and much ongoing research is directed at understanding whether this is an intrinsic limitation (e.g. due to alloy disorder scattering), or due to imperfections arising in the growth and fabrication process. In this thesis, a detailed theoretical study is presented of the hole mobility in single sub-band Si1-xGex heterostructures.

No description available.

No description available.

In recent years, a large number of black holes have been presented as candidates for an evasion of the "no-hair" conjecture. These examples typically have two features: a non-Abelian gauge field and instability. A large part of this thesis is devoted to a detailed study of the Einstein-Yang-Mills-Higgs (EYMH) black holes, including the analytic proof of the evasion of the "nohair" theorem in this case and proving that the black holes are unstable. We also consider an example of a "hairy" black hole not involving a non-Abelian gauge field, which arises in a higher derivative model of gravity derived from string theory, and prove analytically how the "no-hair" theorem is evaded. The rest of this thesis is concerned with the thermodynamics and quantum field theory of these black holes. In a first order approximation to the unknown theory of quantum gravity, we calculate the entropy of the "hairy" black holes. This turns out to be divergent, and parts of the divergences are attributed to the effect of hair on information loss processes occurring as the black hole evolves in time. We pursue this idea further by making a preliminary estimate of the magnitude of the quantum de-coherence effects on the state of the quantum field as time proceeds. These processes may be of interest phenomenologically in the future. The extension of the theory to non-static geometries is also discussed, by describing the results of bringing rotation into the picture. We prove that the Hartle-Hawking state is not regular everywhere outside the event horizon of a Kerr black hole, with the result that quantum field theory on rotating black hole space-times is more complicated than on static geometries.