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

• Cu–Ti thin films of the whole composition range were made by magnetron-co-sputtering.
• The films containing 25–75 at.% Cu appear amorphous and have a monolithic microstructure.
• Residual film stresses, Young's moduli and resistivities show strong dependences on composition.
• Combination of advanced film properties offers a broad spectrum of applications.

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 75 at.% Cu exhibit favorable mechanical properties.