Fabrication and Characterization of SiGe Microdisks

Within the last years computers became faster and more powerful. In the meantime the limiting factor for the calculation power is partially the communication-speed with the memory. The problem hereby is that the internal data transfer is purely electric up to now. For this reason intense research is performed in order to realise silicon-based wave-guides. In order to be able to offer computers at a low price also in the future, it is necessary that the light source on chip can be realised by means of silicon-technology. It was possible within the last decade to realise a silicon and a germanium laser. However, both approaches are so far not suited for miniaturisation and therefore it is not possible to put them on a chip. Within the last decade it was further realised that if one structures SOI samples with or without Ge structures in them into micro-disks, one can observe silicon based luminescence even at room temperature. It was demonstrated that one can shift the luminescence to around 1500nm with the help of Ge-islands. This wavelength would be well suited for silicon wave-guides. In the present thesis the investigations of such silicon micro-disks, were systematically continued. Also investigations on unstructured SOI material were performed and compared with the results from the disks. In the present thesis not only the luminescence at room temperature but also the luminescence at cryogenic temperatures was recorded, in order to understand the physical mechanisms which lead to room temperature luminescence.