Abstract
We have investigated formation of 
on various grain sizes of polycrystalline Si (poly‐Si) with emphasis on its thermal stability. As the grain size of poly‐Si decreases, 
phase is formed at lower temperature because of the diffusion of Co atoms along grain boundaries of poly‐Si during the rapid thermal annealing process. The enhanced reaction of cobalt with silicon on small‐grain‐sized poly‐Si creates a rough 
interface, which becomes thermally unstable. 
formed on amorphous Si showed less thermal stability than that found on medium and large grain sized poly‐Si. © 2000 The Electrochemical Society. All rights reserved.