Rapid Thermal Annealing for Reduced Leakage and Enhanced Endurance of Reactive-Sputtered AlScN-Based Ferroelectric Memory Capacitors

초록

In this study, we investigate the effects of rapid thermal annealing (RTA) in a nitrogen ambient on Al0.8Sc0.2N metal-ferroelectric-metal capacitors. The RTA treatment of up to 13 min on an as-deposited AlScN film markedly improves electrical reliability while maintaining remanent polarization largely unchanged. The leakage current density decreases from 152.63 to 71.37 mA/cm2, and endurance increases to 5000 cycles. X-ray diffraction analysis reveals enhanced crystalline and improved c-axis orientation, which mitigates grain-boundary defects and suppresses leakage pathways. The RTA promotes Pt diffusion, resulting in an 11% increase in the dielectric constant. Moreover, it introduces tensile strain that reduces the coercive field by lowering the ferroelectric switching barrier. These findings indicate that the RTA process in a nitrogen atmosphere is an effective approach for improving the quality of AlScN thin film, thereby supporting the development of its reliable ferroelectric devices.

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