Interfacial Reactions of Nickel and Cobalt thin Films on Silicon

Abstract

The interactions of metal thin films with silicon has been of great interest for its practical applications as means of forming metal silicide contacts in microelectronic industry. Nickel and cobalt thin films on silicon share many important similarities. Firstly, both Ni and Co are transition metals. Secondly, both Ni and Co atoms are found to be dominant moving species during thin film reactions. Thirdly, the formation of silicides follows the sequence of Ni2 (Co2 )Si, Ni(Co)Si and Ni(Co)Si2 with increasing annealing temperatures. Fourthly, both Nisi2 and CoSi2 have a CaF2 structure with small lattice mismatch (< 1.1 %) with silicon and are known to grow epitaxially on low index planes of Si. In this study, we report the results of our study on the factors influencing the formation and growth of nickel and cobalt silicides on silicon.