Dielectric Enhancement of Atomic Layer-Deposited Al 2O 3/ZrO 2/Al 2O 3 MIM Capacitors by Microwave Annealing

摘要

For metal-insulator-metal (MIM) capacitors applicated in the fields of RF, DRAM, and analog/mixed-signal integrated circuits, a high capacitance density is imperative with the downscaling of the device feature size. In this work, the microwave annealing technique is investigated to enhance the dielectric characteristics of Al~(2)O~(3)/ZrO~(2)/Al~(2)O~(3)based MIM capacitors. The results show that the permittivity of ZrO~(2)is increased to 41.9 (~?40% enhanced) with a microwave annealing at 1400?W for 5?min. The substrate temperature is lower than 400?°C, which is compatible with the back end of line process. The leakage current densities are 1.23?×?10_(?8)and 1.36?×?10_(?8)?A/cm_(2)for as-deposited sample and 1400?W sample, respectively, indicating that the leakage property is not deteriorated. The conduction mechanism is confirmed as field-assisted tunneling.