Abstract
Silicon based semiconductor materials are widely used material in electronics industry. Silicides have been extensively studied to the past several decades. In this study, metal induced crystallization of amorphous silicon and synthesis of tantalum silicide nanowires based on nickel silicide have been investigated. At the first part of the thesis, Ni induced crystallization, focusing on the distributed Ni atoms at leading front of the silicon dendrites. The concentration of nickel was very low in crystalline silicon territory, and sharply increased at the interface of C-Si / NiSi2. On the contrary, the nickel contents at the interface of A-Si / NiSi2 decreased gradually and extended to amorphous silicon region. It is the first time for direct observation of Ni distribution in the Si nodule, and at the interface of C-Si / NiSi2 as well as A-Si / NiSi2 by using the EDS line scan measurements. The results may provide the direct evidence to the solution of the long-time debating problem which is the nickel diffusion mechanism at the leading front upon MILC process. In the second part of the thesis, a novel nanowires - nickel induced tantalum silicide nanowires was synthesized. The diameters of the nanowires are measured at about 20-25 nm. The length distribution of the nanowires is within several micrometers, and the maximum length has been observed to be twenty micrometers. Substrate effect, temperature effect, time effect and Ni thickness effect on wire growth were of great important in our experiment. A plausible growth model is inferred to be vapor-solid growth process (VS) for growth of silicide nanowire. Moreover, the Ni concentration of Ta-silicide nanowires increases when a little Fe element was added in the Ni layer. Furthermore, TaSi2 silicide nanowires have shown superior field emission performance compared with the other types of materials, which present a great potential application for the FE emitter materials.