High-temperature leakage improvement in metal-insulator-metal capacitors by work-function tuning

Using low-cost and high work-function Ni, a low leakage current of 5 x 10(-6) A/cm(2) at 125 degrees C is obtained in a high 25-fF/mu m(2)-density SrTiO3 metal-insulator-metal (MIM) capacitor processed at 400 degrees C. This is approximately two orders of magnitude better than the same device using a TaN electrode, with added advantages of improved voltage and temperature coefficients of capacitance. This work-function tuning method also has merit for achieving both low thermal leakage and high overall k value beyond previous laminate structure.