Intense photoluminescence from strained SiGe sub-100 nm wires selectively grown on Si by LPCVD

Selective epitaxial growth by low pressure chemical vapor deposition has been used to produce SiGe-heterostructures in oxide-windows parallel to 〈110〉 or 〈100〉 directions on (001) silicon substrates. For 〈110〉 oxide-wall directions, {111} and {311} facets are formed at the edge of the epitaxial areas, while only {110} facets develop for 〈100〉 directions. Transmission electron microscopy characterizations have clearly shown the formation of quantum wires near the intersecting (001) and {110} planes. The wires have a regular width of 100 nm and a thickness of 6 nm and show a very strong photoluminescence.