Ni‐Catalyzed Growth of Silica Nanowires From Amorphous Silicon Films and Growth Mechanism

The fabrication of amorphous silica nanowires (NWs) using an amorphous silicon (a‐Si) film grown by plasma‐enhanced chemical vapor deposition is demonstrated. Fabrication is achieved by conventional high‐temperature annealing of an a‐Si layer coated with a thin Ni film. Annealing of the Ni (≈20 nm)/a‐Si (≈1 μm) structure at 1100 °C for 1 h is shown to clearly result in the formation of densely packed amorphous silica NWs with diameters in the range from 35 to 70 nm. A comparison of energy dispersive X‐ray analyses on the tip and body of an NW demonstrates that NW growth proceeded via the solid–liquid–solid mechanism. Cross‐sectional SEM images of sample covered with silica NWs is grown by using a‐Si films deposited using conventional plasma‐enhanced chemical vapor deposition and coated with thin Ni layers. The growth of silica NWs is achieved by thermal annealing of the resulting Ni/a‐Si structures at a temperature of 1100 °C for 1 h.