Preferentially oriented and epitaxial Al films have been deposited by ionized cluster beams (ICB). The thermal stability of these films has been examined by SEM, AES, ion backscattering, and electrical characterization. In preferentially oriented films, long electromigration lifetime and low-temperature contact formation are expected. In epitaxial films on silicon, alloy penetration at the interface, a shift in barrier height, and degradation of crystalline quality were not observed after heat treatment up to 550 °C. Extremely long electromigration lifetime was also confirmed. Epitaxial growth Of Al film on CaF2, GaAs, and sapphire was attempted and preliminary results are given.