We demonstrate a high-performance TaN/SrTiO3/TaN metal-insulator- metal (MIM) radio-frequency (rf) capacitor with good device integrity of very high capacitance density of 44 fF/mu m(2), small voltage linearity alpha of 54 ppm/V-2 at 2 GHz, and a small capacitance reduction 3.5% from 100 KHz to 10 GHz. Such large capacitance density can largely reduce the device size used in rf integrated circuits. (c) 2007 The Electrochemical Society.