Authors: J.H. Lee, M. Carpenter, E. Eisenbraun, Y. Xue, R. Geer
Affilation: University at Albany - State University of New York, United States
Pages: 153 - 156
Keywords: silicon nanowire (SiNW), solid-liquid-solid (SLS) mechanism, metal-silicide-coated SiNWs
Self-assembled Si nanowires (SiNWs) have been synthesized and characterized as a template for surface metal silicide formation to investigate confinement of electron transport at the nanowire surface. Silicon nanowires with diameters ranging from 5 to 180 nm were synthesized via solid-liquid-solid (SLS) mechanism on Si (100) and (111) substrates with a sputtered Au film as catalyst in an oxygen-filtered Ar ambient. Metal deposition on SiNW templates was carried out via physical vapor methods and atomic layer deposition methods. Post-deposition thermal processing was carried out for silicide formation. Post-anneal nanowire surface morphology was sensitivity to anneal temperature and ramp rate. Rapid ramps resulted in an atomically-smooth SiNW template morphology. Slow annealing resulted in a rough SiNW surface morphology indicative of nonuniform silicide domain formation. Metal-silicide coated wires were dispensed on metal-patterned Si wafers to carry out two-point and four-point electrical conductivity measurements. Electrical contacts were formed via FIB-based Pt deposition. Metal-silicide-coated SiNWs exhibited an improvement in electrical of several orders of magnitude, as expected. Structural and compositional properties of these wires were analyzed using SEM, EDS, and transmission electron microscopy (TEM). Preliminary analyses imply variable thickness of the metal silicide region based, in part, on deposition methodology and thermal process parameters.