Electrical and reliability characterization with an optimized extrapolation model of two- and three-dimensional metal-insulator-metal decoupling capacitors with ZrAlxOy high-κ dielectric under BEoL-friendly conditions

Abstract

This study investigates the material properties, electrical characteristics, and reliability/lifetime aspects of ZrAl_xO_y dielectric films deposited by atomic layer deposition for Metal-Insulator-Metal decoupling capacitors in advanced CMOS technology under Back-End-of-Line-friendly conditions. Through experimental investigation, including structural and electrical characterization, the impact of Al concentration on capacitance behavior, leakage current, and breakdown characteristics in both 2D and 3D configurations is explored. Results indicate that higher Al concentrations contribute to higher field linearity and reduced leakage in both topologies, while thinner dielectrics exhibit a power-law relationship with breakdown temperature. Notably, 3D samples demonstrate a breakdown behavior less influenced by chemical composition. Lifetime analyses reveal excellent reliability in 2D devices with the highest Al concentration, necessitating higher Al concentrations to improve reliability, especially in challenging deep 3D topologies. These findings underscore the importance of material composition in conjunction with structural stability and their relation to reliability, ensuring stable and long-term performance of decoupling devices.