Enhancing CoCr(Pt)Ta target's pass-through flux for magnetron sputtering

The transmitted DC magnetic field for CoCr(Pt)Ta sputtering targets, containing 2-6 at.% Ta and 0 11 at.% Pt, on magnetron cathodes is investigated. If the Ta content exceeds the solubility limit of 1.5-2 at.%, heat treatment just below the peritectic temperature for Co/sub 7/Ta/sub 2/ formation results in the transformation of /spl lambda//sub 3//Co/sub 2/Ta precipitates or dissolved Ta into Co/sub 7/Ta/sub 2/ phase. Finely dispersed Co/sub 7/Ta/sub 2/ precipitates are formed which seem to exert enough lattice strain to support the martensitic transformation of high-temperature fcc into room temperature hcp Co-Cr solid solution. Since the space-averaged hcp Co-Cr crystal has a lower permeability than the fcc crystal, such target material shows at least a 60% increase in its transmitted magnetic field on magnetron cathodes.