Micro texture dependence of the mechanical and electrical reliability of electroplated copper thin film interconnections

Both mechanical and electronic properties of electroplated copper films used for interconnections were investigated experimentally considering the change of their micro texture caused by heat treatment. Since those properties varied drastically depending on the electroplating conditions and thermal history after the electroplating, a novel evaluation method of the crystallinity of grains and grain boundaries of the electroplated copper thin films has been proposed by applying the conventional electron back scatter diffraction method. It was found the porous grain boundaries in the films cause brittle mechanical and electrical fractures of the films. The proposed method was effective for evaluating the crystallinity of grain boundaries quantitatively, and thus, estimating both the mechanical and electrical properties of the films used for mass production.