Epitaxial CoSi2 by solid phase reaction of Co/Ti and Co/Hf bilayers on Si(001)
TEM and RBS studies of the solid phase reaction of Co/Ti- and Co/Hf/Si(001) layer systems are reported. In addition to conventional annealing procedures a special thermal treatment was applied to investigate the intermediate stages of the reaction during heating up. With rising temperature a complex CoSi-phase sequence was observed which finally results in the growth of epitaxial CoSi2. The emerging silicide phases were proved to grow with preferred orientation relations to the substrate. The observed growth behaviour is compared for both the systems and discussed considering aspects of energy minimization and material supply under the conditions of a thin film reaction.
cosi2 solid phase reaction bilayers tem silicides