Crystallinity and stoichiometry engineering in TiO2 thin films via O3 post-treatment for enhanced dielectric properties

초록

As dynamic random-access memory devices continue to scale down, maintaining high permittivity in nanometerscale dielectric thin films is a critical challenge to overcome. However, an inevitable presence of oxygen vacancies in high-k materials leads to degraded electrical performance and interfacial instability. In this study, O3 post-treatment was applied to 20 nm thick TiO2 thin films deposited by thermal atomic layer deposition to modulate oxygen stoichiometry and enhance physical properties. It was confirmed that a 15 min O3 exposure after TiO2 growth effectively achieved fully oxidized bonding states and improved crystallinity. In particular, a high dielectric constant of 52 was achieved in an anatase phase and the equivalent oxide thickness value was decreased from 1.83 nm to 1.45 nm without compromising leakage current performance.

키워드