A homogeneous crystalline Sm2 Ti2 O7 (ST) phase was formed in films grown at temperatures ranging between 100 and 200 °C and subsequently annealed at 900 °C. The ST film had a large dielectric constant of 58, which is similar to that of ST ceramics. The leakage current density of the ST film was low and the Poole-Frenkel emission was suggested as being the leakage current mechanism. The ST film had a negative quadratic voltage coefficient of capacitance (VCC), possibly due to the dipolar relaxation. The 100-nm-thick ST film had a high capacitance density of 5.2 fFμ m2 with a low leakage current density of 1.34 nA cm2 at 2 V. Its quadratic and linear VCCs were -99.5 ppm V2 and 11 ppm/V, respectively, with a low temperature coefficient of capacitance of 135 ppm°C at 100 kHz. These results confirmed the potential for the ST film to be used as a high performance metal-insulator-metal capacitor.
ASJC Scopus subject areas
- Physics and Astronomy(all)