The optical properties of silicon and germanium nanowires grown within the pores of hexagonal mesoporous silica matrices have been characterised by ultraviolet absorption and photoluminescence (PL) spectroscopy. A clear blue-shift in the PL of the semiconductor composite materials was observed as the diameter of the nanowires decreased from 85 to 22 A ˚.Powder X-ray diffraction revealed that, as the diameter of the confined nanowires decreased, the strain on the crystallographic structure of the nanowires increased, due to escalating lattice expansion, resulting in a shift in the PL maximum to higher energies. The ability to manipulate the optical properties in templated semiconductor nanowires, through strain engineering, has important implications for the design of future optical devices.

We report on vertically stacked horizontal Si NanoWires (NW) p-MOSFETs fabricated with a replacement metal gate (RMG) process. For the first time, stacked-NWs transistors are integrated with inner spacers and SiGe sourcedrain (S/D) stressors. Recessed and epitaxially re-grown SiGe(B) S/D junctions are shown to be efficient to inject strain into Si p-channels. The Precession Electron Diffraction (PED) technique, with a nm-scale precision, is used to quantify the deformation and provide useful information about strain fields at different stages of the fabrication process. Finally, a significant compressive strain and excellent short-channel characteristics are demonstrated in stacked-NWs p-FETs.

No abstract