Nozzle-type partially ionized beam deposition of Cu thin films at a system pressure of 5 × 10−6 to 7 × 10−6 Torr was conducted in order to fabricate Cu metallization with high-quality CuSi interfaces. In order to prevent diffusion of the Cu toward the Si and silicide formation, the depositions with various acceleration voltages were performed at room temperature. X-ray diffraction patterns showed all the as-grown films having the 〈111〉 Cu direction normal to the (100) Si plane regardless of the acceleration voltage. Auger electron spectroscopy demonstrated that there was no residual carbon detection in the bulk of the as-grown films. The thickness of the all as-grown Cu films was 2 000 Å as confirmed by low-magnitude cross-sectional transmission electron microscopy, i.e. growth rates of the Cu film by partially ionized beam deposition at room temperature were almost independent of the acceleration voltage. Furthermore, cross-sectional transmission electron microscopy showed a sharp CuSi interface and large-grain polycrystalline Cu films with twin defects. Atomic force microscopy under ambient conditions showed all the films had very smooth surfaces which were greatly reduced with the acceleration voltage. A scratch test showed good adhesion in all the films. These results indicate that the nozzle-type partially ionized beam deposition at room temperature can be used for Cu thin film metallization for semiconducting applications.