Growth, structure and properties of magnetron sputtered ultra-thin WTi films

ABSTRACTRefractory metal alloy WTi films were elaborated by magnetron sputtering from an alloyed target (W:Ti ∼ 70:30 at%). Film continuity threshold has been determined at 4.5 ± 0.2 nm using in situ surface differential reflectance (SDR) technique. Prior to film continuity, deposition of a continuous interfacial layer is suggested by both in situ and real-time SDR and wafer-curvature techniques. After continuity, WxTi1-x films (9.5 nm thick WTi films) have a body-centered structure with a {110} fiber texture. Composition (x) and microstructure can be tuned varying working pressure. A transition from compressive to tensile residual stresses was observed by ex situ XRD and wafer-curvature methods. Size dependent resistivity is obtained and slightly varies as a function of working pressure.