Nano-Sized Copper Films Prepared by Magnetron Sputtering

Copper films with a thickness varying from 6 nm to 100 nm are prepared by magnetron sputtering. The films are characterized by homogeneous and fine-grained microstructure. The X-ray diffraction data confirm formation of a copper fcc phase orientated predominantly in the (111) direction. Depending on the growth conditions, the size of Cu grains in the films varies from 7 nm to 20 nm. The refractive index of the films increases from 0.52 to 1.22 with decreasing copper film thickness. The transmittance of the films decreases as their thickness increases from 6 nm to 62 nm, and the transparency of the films with the same thickness decreases with increasing sputtering power and decreasing argon flow rate. The surface resistivity of the films decreases from 8.89±0.06 Ω/sq to 1.47±0.01 Ω/sq as their thickness increases from 20 nm to 70 nm.