Structural and Electrical Properties of Mn-Doped Bi4Ti3O12 Thin Film Grown on TiN/SiO2/Si Substrate for RF MIM Capacitors

Mn-doped Bi4Ti3O12 (M-B4T3) films were well formed on a TiN/SiO2/Si substrate at 200 degrees C without buckling using RF magnetron sputtering. The leakage current density of these films was considerably influenced by the oxygen partial pressure (OPP), which was attributed to the presence of oxygen vacancies or oxygen interstitial ions. The film grown under 2.8-mtorr OPP showed the lowest leakage current density. The M-B4T3 films grown at 200 degrees C showed a high dielectric constant of 38 with a low loss in both kilohertz and gigahertz ranges. The 39-nm-thick film showed a high capacitance density of 8.47 fF/mu m(2) at 100 kHz, and its temperature and quadratic voltage coefficients of capacitance were low at approximately 370 ppm/degrees C and 667 ppm/V-2, respectively, with a low leakage current density of 7.8 x 10(-8) A/cm(2) at 2 V. Therefore, the M-B4T3 thin film grown on a TiN/SiO2/Si substrate is a good candidate material for high performance, radio frequency metal-insulator-metal capacitors.