NANOMETER-SCALE SI AU BILAYER DOTS FABRICATED BY SELF-ASSEMBLY PROCESS THROUGH LIQUID-PHASE EPITAXY/

Nanometer-scale Si/Au bilayer dots were fabricated on a flat Si surfac e. Au particles were produced by the gas-phase condensation method and deposited on the Si substrate. Post-thermal annealing in ultrahigh va cuum resulted in the formation of bilayer dots. The kinetics of bilaye r formation was described as a process of self-assembly through liquid phase epitaxy. Then, one-directional diffusion was observed, although interdiffusion between the two elements commonly occurred at the Si/A u interface. The Au particles play the role of the transport medium. N amely, a few monolayers of the surface Si were dissolved into Au, form ed SiAu alloy which was then regrown on the surface shape of dot with the Au particle on it. (C) 1998 Acta Metallurgica Inc.