Fabrication of silica nanowire bunch arrays in SiO vapor generated by oxygen plasma etching of silicon

This paper reports a three-step fabrication method for highly ordered silica nanowire bunch arrays of diversiform shapes. After patterning of organic polymers on Si substrates through photo lithography, oxygen plasma bombardment is applied to fabricate nanowire bunch arrays. On one hand, oxygen plasma exploits Si source from the substrates, and, subsequently, the gaseous Si react with active oxygen to form SiO vapor. On the other hand, oxygen plasma erodes the polymer patterns and, simultaneously, make them electrostatically attract the SiO material to form straight silica nanowire bunches. Based on this approach, standing nanowire bunch arrays of different sizes and different shapes are achieved on selective areas or structures. The nanowire bunches are able to bend toward a gallium focused-ion-beam irradiation, from different positions, in different directions and at different angles.