Stress development and relaxation during reaction of a cobalt film with a silicon substrate

摘要

Stress development and relaxation during reaction of Co films on Si(OOl) substrates has been studied. Using in-situ synchrotron x-ray diffraction and curvature measurements during annealing, several changes in curvature have been clearly correlated with successive appearing and disappearing of Co silicides : Co_2Si, CoSi and finally CoSi_2 around 500°C. Whereas the CojSi and CoSi phases grow under compressive stress, CoSi_2 grows under tensile stress. This stress buildup is discussed in terms of specific volume change during the Co-Si reaction.