This paper presents the fabrication of ametal-insulator-metal(MIM) antifuse structure consisting of insulators sandwiched between top electrode, Al, and bottom electrode, TiW and additionally studies on antifuse properties depending on the condition of insulator. The intermetallic insulators, prepared by means of sputter, comprised of silicon oxide and tantalum oxide. In such an antifuse structure, silicon oxide layer is utilized to decrease the leakage current and tantalum oxide layer, of which the dielectric strength is lower than that of silicon oxide, is also utilized to lower the breakdown voltage near 10V. Finally sufficient low leakage current, below InA, and low programming voltage, about 9V; could be obtained in antifuse device comprising Al/Ta₂O₃(10nm)/SiO₂=(10nm)/TiW structure and OFF resistance of 3.65㏁ and ON resistance of 7.26Ω could be also obtained. This Ta₂O₃/ SiO₂= based antifuse structures will be promising for highly reliable programmable device.