Structure and properties of sputter deposited crystalline and amorphous Cu–Ti films

Thin film metallic glasses (TFMG) can possess a variety of advantages against crystalline thin metal films. High strength and toughness as well as specific corrosion resistivity are features, which can be widely used in MEMS (micro-electromechanical systems), lab-on-a-chip or surface acoustic wave (SAW) device applications. Amongst others, the Cu–Ti binary alloy system is known for having a moderate glass forming ability (GFA) in mid-composition range. In the present study a systematic characterization of sputter deposited Cu–Ti thin films in dependence on the chemical composition is carried out. Intrinsic stress, Young's modulus, surface roughness and electrical resistivity are discussed with respect to the present phases and microstructure. Especially the films within the amorphous range from 25 to 75at.% Cu exhibit favorable mechanical properties.