FABRICATION OF SILICON NANOWIRES

Pentagon-shaped silicon wires with Linewidth around 300nm are successf ully fabricated by using the Si/SiGe epitaxy technique, reactive ion e tching, and subsequent selective chemical etching. The nanowires are o xidized in wet O-2 at 750 degrees C and 850 degrees C. The oxide and i nterface morphology are characterized by cross-sectional scanning elec tron microscope images. It is found that the oxidized nanowire followi ng oxidation at 750 degrees C still keeps its pentagon shape even if i t has been oxidized for 19 h. However, the oxidized samples at 850 deg rees C become circular in shape. The oxidation-temperature dependence of the sample shapes is discussed. Our results should be useful in gen erating silicon nanowires coated with SiO2 in microelectronic technolo gy with careful selection of the SiO2 growth temperatures.