Kinetics of platinum silicide formation during rapid thermal processing

Silicide formation in Pt-Si bilayers was induced by rapid isothermal annealing using incoherent light from tungsten halogen lamps. The growth sequence of the Pt2Si and the PtSi phases that evolved as the result of the solid state reaction in the bilayers was monitored by Rutherford backscattering spectroscopy. The identification of the phases was confirmed by x-ray diffraction. Activation energies for the formation of the Pt2Si and the PtSi phase were determined to be 1.38 and 1.67 eV, respectively. These values agree with the reported results of the formation of these silicides by furnace anneals. Hence, rapid isothermal anneals do not appear to enhance the solid-state reactions in Pt-Si bilayers. It was also found that even rapid thermal anneals led to the formation of a very thin oxide that provided protection to the underlying silicide during selective Pt etch.