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.

Effective Refractory Metal Alloy Barrier Layer for High Temperature Microelectronic Device Application

ABSTRACTThe oxidation and diffusion of Molybdenum layer sputter-deposited on 2μm CVD diamond grown on silicon substrate has been studied. The Mo layer was protected by refractory metal silicide barrier layer. The samples were annealed in air ambient at 500°C over 30 hours. The oxidation of the samples was monitored with Rutherford Backscattering Spectroscopy (RBS). The effect of reactive sputtering of refractory silicide target in argon-nitrogen gas mixture (5% nitrogen by flow rate) on the barrier characteristics was investigated. The sheet resistivity of the barrier layer on SiC substrates as a function of annealing time in air at 500°C is reported. The surface structure and morphology of the refractory silicide films was determined with X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM).