This study investigated the effect of resistive switching on Pt/Al2O3/Cu/Al2O3/ITO multilayer structures grown by RF/DC magnetron sputtering. A reproducible unipolar switching free forming was found only for the negative voltage. The SET and RESET processes occurred at very low voltage values, which may be advantageous for practical applications. The ON/OFF ratio was approximately five orders of magnitude for more than 10(3) s, which is desirable for nonvolatile memories such as resistive random-access memories (ARAMs). We explain the unipolar behavior of the characteristic (I-V) curves in terms of the formation and rupture of conducive filaments, connected via a Cu metal layer.