Grain boundary reactive diffusion during Ni Si formation in thin 2 films and its dependence on the grain boundary angle

The process of reactive diffusion of Ni in thin films is studied during the low temperature 2508C-3008C.growth of Ni2Si on Si 100.and Si 111.substrates. The silicide on the Si 111.substrates presents textured structures which probably involves mainly low-angle -158.grain boundaries, whereas the grains of the silicide on the Si 100.substrates do not show texture correspondingly presenting a random predominantly high-angle grain boundary distribution. Assuming Ni grain boundary diffusion being the dominant limiting process of the solid-state reaction, the corresponding grain boundary reactive diffusion coefficient is determined from the kinetics of the silicide formation. It is observed that the coefficient belonging to low-angle boundaries is smaller than that measured in randomly distributed high-angle boundaries and they are determined to be Dgbs1.74=10y2 exp y1.22rkT.cm2rs and Dgbs7.45=10y1 exp y1.35rkT.cm2rs, respectively. The results indicate similarity between normal and reactive diffusion processes. q1999 Elsevier Science B.V. All rights reserved