CMOS-Compatible Precise Placement of Ge Quantum Dots for Nanoelectronic, Nanophotonic, and Energy Conversion Devices

We have developed a self-assembled CMOS compatible scheme for the generation of Ge QDs through thermal oxidation of Si1-xGex patterned structures as well as demonstrated precise QD placement by guiding Ge nucleus migration along the oxidation path and thus arranging them onto targeted locations where the ultimate oxidation occurs. Thereby a single QD self-aligned with electrodes through nanoscale tunnel barriers of SiO2/Si3N4 is realized for an effective management of single electron tunneling. On the other hand, using the fidelity of lithographic patterning and selective oxidation of SiGe pillars well-organized 3D stacked Ge QDs are precisely placed vertically and laterally, and the stacking number is managed by conditions of etching and layer deposition. Stacked QDs luminescence tunable over the visible and possess low thermal conductivity, showing promise for nanophotonic and energy conversion devices.