Spontaneous nickel monosilicide nanowire formation by metal induced growth

Nickel monosilicide (NiSi) nanowires (NWs) were grown at a relatively low temperature of 575 °C by the Metal Induced Growth (MIG) method without using a gas type silicon source. In the MIG technique, silicon dioxide is first plasma deposited onto a Si wafer followed by 20-160 nm of Ni. Si is then deposited by D.C. magnetron sputtering on the heated substrate. A nickel silicide is first formed which then leads to nanowire formation. Nanowires were a single crystal structure, 20-100 nm in diameter and 1-10 μm in length. Composition and structure were verified by high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. The mechanism of NiSi nanowire formation is discussed herein.