Controllable Fabrication of GeSi Nanowires in Diameter of About 10nm Using the Top-Down Approach

Ordered GeSi nanowires with a \sim10 nm cross section are fabricated utilizing top-down and Ge condensation techniques. In transmission electron microscopy measurements, the obtained GeSi nanowires exhibit a single-crystal structure and a smooth Ge/SiO_2 interface. Due to the linear relationship between the cross-section area and the initial pattern size under the self-limited oxidation condition, the cross-section size of GeSi nanowires can be precisely controlled. The Raman spectra reveal a high Ge fraction (up to 97%) and a biaxial strain of the GeSi nanowires. This top-down technique is promising for fabrication of high-performance GeSi nanowire based optoelectronic devices.