Dielectric Constant Enhancement and Leakage Current Suppression of Metal-Insulator-Metal Capacitors by Atomic Layer Annealing and the Capping Layer Effect Prepared with a Low Thermal Budget

A high-quality nanoscale oxide layer with a high dielectric constant and a low leakage current prepared at a low thermal budget is critical to advanced metal-insulator-metal (MIM) devices. In this study, the film density, crystallinity, dielectric constant, and leakage current of the ZrO2 thin film are significantly improved by the atomic layer annealing (ALA) and the titanium nitride (TiN) capping layer effect at a low process temperature of only 300 degrees C without any postannealing treatment. Hence a high ZrO2 dielectric constant of 35.2, a low equivalent oxide thickness of 0.64 nm, and a leakage current density lower than 10-7 A/cm2 are demonstrated in the MIM capacitors. This study demonstrates the significant impacts of the ALA and capping layer effects on the film quality and electrical characteristics of nanoscale thin films for high-performance devices.