BaTi 4 O 9 thin films for high-performance metal-insulator-metal capacitors

The dielectric and electrical properties of a BaTi4O9 film were investigated in order to evaluate its potential use in metal-insulator-metal (MIM) capacitors for rf/mixed signal integrated circuits. A high capacitance density of 4.62fF∕μm2 along with a low tanδ of 0.0025 were obtained at 100 kHz. A high capacitance density of 4.12fF∕μm2 and a high quality factor of 322 were also achieved at 2 GHz. The leakage current density was approximately 1nA∕cm2 at ±2V. Small linear and quadratic voltage coefficients of capacitance of 110ppm∕V and 40.05ppm∕V2, respectively, and a small temperature coefficient of capacitance of −92.157ppm∕°C at 100 kHz were obtained. These results demonstrate that the BaTi4O9 film is a good candidate material for MIM capacitors.