A study on the dependence of DC electrical properties and nanostructure of Cu thin films on film thickness

Abstract

This paper reports the correlation between film thickness, nanostructure and DC electrical properties of copper thin films deposited by PVD method on glass substrate. X-ray diffraction (XRD) and atomic force microscopy (AFM) were used for crystallography and morphology investigation, respectively. Resistivity was measured by four point probe instrument, while a Hall effects measurement system was employed for Hall Effect analysis. The grain size calculated from XRD and AFM, roughness, resistivity, hall coefficient, carrier concentration and mobility were plotted as a function of thickness. The result showed amorphous structure for 20 nm thickness, but with increasing the film thickness, Cu(111) preferred orientation was observed. The grain size, roughness and concentration of carriers increased and resistivity, hall coefficient and mobility decreased with increasing the film thickness. The result of copper thin films electrical investigation showed the value of resistivity and concentrations of carriers come to bulk state value at approximately 160 nm thickness.