Growth and characterization of relaxed low-dislocation silicon germanide alloys grown on thin silicon films

Recently, there has been an interest in relaxed low-dislocation films of {dollar}rm Sisb{lcub}1-x{rcub}Gesb{lcub}x{rcub}{dollar} for the growth of commensurately strained SiGe heterostructures. These relaxed films allow for increased flexibility in designing heterostructures and offer benefits that are just beginning to surface such as enhanced electron mobilities for strained silicon on relaxed {dollar}rm Sisb{lcub}1-x{rcub}Gesb{lcub}x{rcub}{dollar}.; In this thesis, we studied the growth and relaxation of {dollar}rm Sisb{lcub}1-x{rcub}Gesb{lcub}x{rcub}{dollar} on very thin Bond-Etchback Silicon on Insulator (BESOI). The thin silicon layer was chemically and thermally etched to allow the thicker SiGe epitaxial layer to easily transfer its strain to the silicon. We also examined the effect of ion-implantation on the viscous flow of the SiO{dollar}sb2{dollar} layer which allows relaxation of the SiGe layer. It is found that the implantation reduces the reflow temperature of the SiO{dollar}sb2{dollar} layer which allows in-situ growth and anneal and it is also found that it improves the relaxation of SiGe layers. We implanted the BESOI substrate with boron and subsequently with oxygen in an attempt to create a borosilicate glass in the SiO{dollar}sb2{dollar} region.; Photoluminescence (PL) and triple-axis x-ray diffraction were used to characterize film quality, Ge concentration and percent relaxation. A dramatic decrease in the annealing temperature required was observed. The PL spectra show a broad band that is believed to relate to the relaxation of the SiGe layer. The intensity of this peak first increases in intensity and then decreases dramatically when the annealing temperature reaches the point when the SiGe layer begins to relax. For the sample grown on implanted BESOI, this peak is shown to disappear completely and we saw the evolution of new bandgap luminescence for the {dollar}rm Sisb{lcub}.7{rcub}Gesb{lcub}.3{rcub}{dollar} layer grown on boron and oxygen implanted BESOI. It is believed that this is primarily due to the reduced reflow temperature and low defect dislocation concentration of the {dollar}rm Sisb{lcub}.7{rcub}Gesb{lcub}.3{rcub}{dollar} film. XTEM was also used to verify the strain transfer mechanism of the Si/SiGe bilayers.; Using the 'substrate-compliant' method outlined here, we also attempted to grow device quality films, such as strained Si quantum wells. We observed quantum well luminescence which can be directly attributed to the conduction band offset of strained silicon. We also attempted to grow pure Ge atop Si, in the form of 20% BSG BESOI. The results are preliminary, but we observed a noticeable improvement in the Ge layer using BESOI.; Finally, we derived an analytical expression for glide velocity using the stress distribution of a bimetal thermostat. In this way, we are able to take into account the substrate compliance and the finite area effect. This would prove to be invaluable if we were to take the 'virtual substrate' concept one step further by patterning mesas on the surface. However, using this formulation, we can easily explain the observation that dislocations glide to the edge of mesas.