Electrical properties of the Sm2Ti2O7 thin films for metal-insulator-metal capacitor applications

Abstract

A homogeneous crystalline Sm2Ti2O7 (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 fF∕μm2 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.

Material, Electrical, and Optical Characterizations of High-K Sm2TiO5Dielectric Deposited on Polycrystalline Silicon

“…It is worthwhile to find alternative material compositions, new processes, and effective treatments to mitigate reliability concerns. For this research, Sm 2 TiO 5 , a promising high-k material with favorable dielectric strength [5][6][7], was formed by RF sputtering on polycrystalline silicon [8]. The dielectric was treated with post-RTA annealing as an effective method for lessening defect structures.…”