Respective mobilities of metal and silicon in disilicides: Bilayers of chromium with molybdenum or tungsten

Abstract

The behaviors of metallic bilayers, chromium-molybdenum and chromium-tungsten, on (100) silicon during isochronal annealing have been studied by Rutherford backscattering of 2.3-MeV 4He+ ions and x-ray diffraction. These experiments were conducted with the aim of obtaining information about the respective mobilities of silicon and metal atoms in the different silicides through a comparison of the temperatures at which the silicides form and those at which they mix (through metal-atom diffusion). The results confirm that the respective silicides form via silicon-atom motion and that the mobilities of the metal atoms are markedly smaller than that of the silicon atoms.