Study of internal stress on electroplating copper used in through silicon via filling

Through silicon via (TSV) is a high performance technique to create 3D packages and 3Dintegrated circuits, compared to alternatives such as package-on-package, because the density of the via is substantially higher. The effect of current density and bath´s organic additives on internal stress of copper electrodeposited from TSV filling methanesulfonate bath has been studied by Surface Profiler, X-ray diffraction (XRD) and Scanning electron microscope (SEM). We show that addition of the organic additives and current density can affect the internal stress of electrodeposited cupper films. The XRD patterns of copper films reveal the presence of (1 1 1), (2 0 0), (2 2 0), and (3 1 1) peaks, intensity of which is connect with the concentration of the organic additives in the plating bath and the current density of electrodeposition.