A memory device Si/Al2 O3/Al2O3-Cu2O/Al2O3/Pt is fabricated by using atomic layer deposition and rf-magnetron sputtering techniques.The memory device including the composite of Al2O3 and Cu2O as the charge storage layer shows a distinguished charge trapping capability.At a working voltage of +11 V a memory window of 9.22 V is obtained.The x-ray photoelectron spectroscopic study shows a shoulder from Cu2+ ions around the peak of Cu1+ ions.It is suggested that the charge-trapping mechanism should be attributed to the defect states formed by the inter-diffusion at the interface of two oxides.