Inference of Current density on Microstructure of Electroplated Cu Thin Film

Abstract

In this paper, we report micro-structural characteristics of electroplated Cu thin films with the variation of the current density applied during the electroplating process. We evaluated the surface roughness, the crystalline texture, the resistivity, and the grain size of the thin film in a wide range of current density (50-1000A/m2). The surface roughness and the resistivity were increased according to the increment of the current density. The ‹111› textured structure was also pronounced as the current density was increased. The scanning ion microscope (SIM) image of the cross-sectional samples revealed that grain size of the film prepared in a high current density was much smaller (0.05-0.5μm) than that of the thin film in a low current density (1-2μm). These results are different from the film prepared by a sputtering process, where a smooth surface was observed in a small grain-sized (<0.1μm) film.