Interfacial reactions on annealing molybdenum-silicon multilayers

The structure and interfacial reaction in sputtered Mo-Si multilayers have been studied using cross-section transmission electron microscopy, electron diffraction, Rutherford backscattering, and low-angle x-ray diffraction. Low-temperature (T<550 °C) annealing was performed in a rapid-thermal-annealing furnace and in situ in the microscope. No solid-state amorphization was observed, in spite of the presence of amorphous alloy interfacial layers in the as-deposited structure. Instead, the amorphous interlayers crystallize, and growth of the crystalline product, hexagonal-MoSi2, proceeds. The bilayer period contracts during the reaction, as the disilicide is more dense than its constituents.