Silicide formation in Ti-Si and Co-Si reactions

Abstract

Titanium silicide and cobalt silicide crystallization and formation reactions are important for the processing of CMOS circuits. We demonstrate that kinetic analysis of these reactions under both high heating rates and isothermal heating conditions allows for the determination of transformation mechanisms. For Ti/Si reactions, we show that the C49 to C54-TiSi2 transformation can not be bypassed using heating rates up to 3000°C/min. For the crystallization of CoSi2 from amorphous Co-Si thin films without ion irradiation, the crystallization kinetics are characterized by three dimensional growth from quickly consumed nucleation sites. With high dose silicon ion implantation of the as-deposited films, the crystallization mechanism changes to homogeneous nucleation and two dimensional growth.