(Digital Presentation) Epitaxially Grown of SiGe on Ge Microbridge and Observation of Strong Resonant Light Emission

We observe strong room-temperature photoluminescence from Ge microbridges formed on Ge-on-Si (110). The Si (110) substrate is employed to fabricate the bridge along [111] direction as uniaxial strain in the [111] direction is expected to be the most effective to bring direct transition. In this study, we grow Ge-on-Si with (110) orientation and fabricate MB along the [111] directions. Due to the low etching rate of the (111) plane, however, etching of the Si under the square-shaped pads is quite difficult. By contrast, we fabricate branch-like MB, where the underneath Si was fully etched owing to the various directions of the etching. As a result, we obtained very strong resonant light emission.