Study on Thermal Oxidation of Si Nanowires

In this paper we reported the results on the low-temperature thermal oxidation of Si nanowires. Various polygon-shaped Si nanowires with linewidths between 100 and 300 nm were fabricated on Si/Si1—xGex/Si heterostructure substrates by using lithography, reactive ion etching, and subsequent selective chemical etching. We find that oxidized Si nanowires following 750 and 775 °C wet oxidation will keep the same shape as the initial unoxidized samples, and all the SiO2 boundaries of oxidized samples will arrive at a circular shape. These results, which should be due to stress effects, provide useful information for understanding the behavior of non-planar oxidation that is used in modern Si nanoelectronic technology.