Deposition of Cu-Ni films by magnetron co-sputtering and effects of target configurations on film properties

Abstract

Structural properties of Cu-Ni alloy films, such as preferred orientation, crystallite size, inter-planar spacing, cross-sectional morphology, and electrical resistivity, are investigated in terms of target configurations that are used in the film deposition by means of magnetron co-sputtering. Two different target configurations are considered in this study: a dual-type configuration in which two separate targets (Cu and Ni) and different bias types (RF and DC) are used and a Ni-on-Cu type configuration in which Ni chips are attached to a Cu target. The dual-type configuration appears to have some advantages over the Ni-on-Cu type regarding the accurate control of atomic composition of the deposited Cu-Ni alloy. However, the dual-type-produced film exhibits a porous and columnar structure, the relatively large internal stress, and the high electrical resistivity, which are mainly due to the relatively low mobility of adatoms. The affects of thermal treatment and deposition conditions on the structural and electrical properties of dual-type Cu-Ni films are also discussed.