ENHANCING COCR(PT)TA TARGETS PASS-THROUGH FLUX FOR MAGNETRON SPUTTERING

The transmitted DC magnetic field for CoCr(Pt)Tn sputtering targets, c ontaining 2 - 6 at% Ta and 0 - 11 at% Pt, on magnetron cathodes is inv estigated. If the Ta content exceeds the solubility limit of 1.5 - 2 a t%, heat treatment just below the peritectic temperature for Co7Ta2 fo rmation results in the transformation of lambda(3)/Co2Ta precipitates or dissolved Ta into Co7Ta2 phase. Finely dispersed Co7Ta2 precipitate s Pre formed which seem to exert enough lattice strain to support the martensitic transformation of high-temperature fee into room temperatu re hcp Co-Cr solid solution. Since the space-averaged hcp Co-Cr crysta l has a lower permeability than the fee crystal, such target material shows at least a 60% increase in its transmitted magnetic field on mag netron cathodes.