Papers Published

1. Hsia, S.L. and Tan, T.Y. and Smith, P.L. and McGuire, G.E., Assured epitaxial CoSi₂ phase formation on (001) Si-on-insulator substrates using CoSi/Ti bimetallic source materials, 1994 Symposium on VLSI Technology. Digest of Technical Papers (Cat. No.94CH3433-0) (1994), pp. 123 - 4 [VLSIT.1994.324426] .
   (last updated on 2007/04/10)

   Abstract:
   We report an assured way of forming epitaxial CoSi₂ films on (001) SOI Si substrates when Co is inexhaustible. This is to use bimetallic CoSi/Ti source materials. For the more commonly used Co/Ti source material, epitaxial CoSi₂ film forms before the Si layer is fully consumed. After the SOI Si has been fully consumed, however, pre-formed epitaxial CoSi₂ reverted back to polycrystalline CoSi, leading to a dramatic sheet resistance increase. This phase reversal phenomenon arises because in using atomic Co as source material, the Gibbs free energy reduction in forming the CoSi and CoSi₂ phases is not too different and consequently CoSi becomes the energetically favorable end phase when Co is still available after all Si atoms have been consumed. In using CoSi as the Co source material, the only energetically favorable reaction is to form CoSi₂

   Keywords:
   cobalt compounds;insulated gate field effect transistors;metallic epitaxial layers;metallisation;semiconductor technology;semiconductor-insulator boundaries;silicon;