Self assemble silicide architectures by directional solidification

Abstract

Directional solidification of eutectics has self assembly characteristics that can fabricate two dimensional periodic arrays of two or more phases. The ordering of the phases can be utilized as a “lithographic technique” to produce porous structures for fabrication of miniature devices. Directional solidification by the Bridgman technique was applied to the eutectic systems Si–TiSi 2 and Si–YSi 2. Patterned growth of TiSi 2 rods occur in the silicon matrix during solidification. Micro-channel structure of pillar arrays of TiSi 2 was produced by silicon dissolution by KOH. Average TiSi 2 rod diameter was 2.5 μm with 99% of the population falling in the 2–3 μm range. Colony formation could not be suppressed in the Si–TiSi 2 system. Patterned growth is not observed in Si–YSi 2 system. Eutectic and hyper-eutectic Si–YSi 2 compositions formed anomalous eutectic microstructure. Microstructure shows dependence upon the solidification rate.