Growth and properties of SiGe structures obtained by selective epitaxy on finite areas

Selective epitaxy growth (SEG) was used to build SiGe optoelectronic devices and nanoscale structures for the future nanotechnology. The growth of strained SiGe on small areas offers some advantages for improvement of device performances. In particular, with relative large area light emitting diodes (LED), the emission efficiency of SiGe diodes can be increased up to 0.1% internal value at room temperature. Further improvements are expected for nanoscale devices. By SEG on mesas, Ge islands can be obtained ordered in lines along the mesas edges. Precise localization of Ge dots can be obtained by SEG in very small oxide windows and even only one island/window is formed. It was shown that nanostructures of size down to 5 nm can be grown by this method.