High-capacitance metal-insulator-metal capacitors using amorphous Sm2 Ti2 O7 thin film

Amorphous Sm2 Ti2 O7 (SmT) films were investigated to assess their potential use in metal-insulator-metal (MIM) capacitors. A 72 nm thick SmT film showed a high capacitance density of 5.2 fFμ m2 with a low leakage current density of 0.12 nA cm2 at 2.0 V. The capacitance density increased with decreasing film thickness to 8.18 fFμ m2 for the 46 nm thick film. The 72 nm thick SmT film had small quadratic and linear voltage coefficients of capacitance of 158 ppm V2 and -283 ppmV, respectively, and a temperature coefficient of capacitance of 207 ppm°C at 100 kHz. Overall, amorphous SmT films are good candidate materials for MIM capacitors.