Observation of quantum interference effects in submicron CoSi2 wires in Si(100)

We report on the structural and electrical characterization of submicron wide cobalt disilicide wires with widths down to 170 nm fabricated by ion beam synthesis. This versatile technique consists of implantation of cobalt through a special implant mask followed by a rapid thermal annealing step. We observed quantum interference effects in CoSi2 wires, which we attribute to weak localization with strong spin-orbit scattering and superconducting fluctuations. Cross-sectional transmission electron microscopy micrographs showed that the thinnest wires have diamondlike shapes due to energetically preferred {111} facets. Analysis of the magnetoresistance at temperatures between 2 and 4 K yielded relatively large phase coherence lengths of 0.5-2.5 mu m very similar to values obtained for epitaxial CoSi2 layers indicating the high crystalline quality of the wires. (C) 1997 American Institute of Physics. [S0003-6951(97)03150-1].