Abstract
Copper thin films are indispensable for the interconnections in the advanced electronic products, such as Through Silicon Via (TSV), fine bumps, and thin-film interconnections in various devices and interposers. However, it has been reported that both electrical and mechanical properties of the films vary drastically comparing with those of conventional bulk copper due to the fluctuation of the crystallinity of grain boundaries in the films. Porous or sparse grain boundaries cause the very high resistivity and brittle fracture of the films. Thus, the thermal conductivity of the electroplated copper thin films should be varied drastically depending on their micro texture based on the Wiedemann-Franz's law. Since the copper interconnections are used for not only electrical conduction but also thermal heat conduction, it is very important to evaluate the crystallinity of the polycrystalline thin film materials quantitatively and clarify the relationship between the crystallinity and thermal properties of the films.
