Optimization of In2O3 doping concentration for high-performance ZrO2-based metal-insulator-metal capacitors

ZrO 2 offers a high dielectric constant and a stable tetragonal crystal structure; however, its performance is limited by leakage current issues arising from scaling. In 2 O 3 doping effectively promotes the formation of the tetragonal phase in ZrO 2 without inducing defect formation or chemical state changes. At the DRAM operating voltage of +0.8 V, the films maintained an excellent leakage current density (<10 -7 A/cm²) while effectively reducing the equivalent oxide thickness ( t ox ). Notably, compared to undoped films, the t ox was reduced by approximately 10-15%, with superior performance observed across various thicknesses. This study demonstrated that In 2 O 3 doping is an effective approach for optimizing the dielectric performance of ZrO 2 , providing crucial design guidelines for addressing scaling challenges in DRAM capacitors while maintaining high dielectric properties.