Low leakage current in metal-insulator-metal capacitors of structural Al2O3/TiO2/Al2O3 dielectrics

Metal–insulator–metal (MIM) capacitors with Al2O3/TiO2/Al2O3 (ATA) dielectrics were fabricated and investigated. At 0 V and frequencies of 100 kHz and 1 MHz, the MIM capacitors with ATA (3/20/3 nm) and ATA (6/20/6 nm) thin films had low leakage current densities of approximately 5.2 × 10−13 and 1.5 × 10−13 A/cm2, respectively, and high capacitance densities of ∼19.48 and ∼20.13 fF/μm2, respectively. The frequency dispersion effect for these MIM capacitors was very small. The electrical transport mechanism, which is the device conduction mechanism, was determined for the varying structures of MIM capacitors.