The compatibility of aluminium layers on plasma-deposited W and WSi/sub 2/ films

The compatibility of Al on plasma-deposited W and WSi/sub 2/ films in an Al sintering process is studied. The compatibility is investigated by measuring the variation of the barrier heights of Al/W/Si and Al/WSi/sub 2//Si Schottky-barrier contact that have been annealed at 400 to 600 degrees C for 30 min. Rutherford backscattering and X-ray diffraction are used to examine the diffusion of Al and the interface constitution of these annealed contacts, respectively. The experimental results show that the barrier heights are almost constant, and no binary or ternary intermetallic compounds are found under 500 degrees C annealing. Thus the plasma-deposited W and WSi/sub 2/ thin films are metallurgically compatible with Al layers in VLSI fabrication.<
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