Germanium-Rich SiGe Nanowires Formed Through Oxidation of Patterned SiGe FINs on Insulator

摘要

In this study, the authors report on the fabrication of Ge-rich SiGe nanowires (SGNWs) by oxidation of SiGe fins on insulator. Nanowires of different shapes and size are obtained by varying the initial fin shape, Ge content, oxidation process temperature, and oxidation time. Transmission electron microscopy observations revealed nanowires with rectangular, square, elliptical, circular, octagonal, and hexagonal cross-sections, with different Ge content. The elliptical, octagonal, and hexagonal facets are unique shapes formed with low-index faces belonging to (110) groups. These possess very high Ge content up to 95percent, and were obtained in the samples oxidized from 850 deg C to 875 deg C. In addition, the in-plane strain in the fabricated SGNWs is evaluated using micro-Raman spectroscopy. The possible mechanism behind the formation and transformation of different nanowire shapes is discussed.