Self-Saturated Deposition and Etching in Atomic-Scale (SDEA) Process of Molybdenum Oxides via Sequential Ozone and Water Reactions

Molybdenum dioxide (MoO₂) has attracted significant attention as a high-work-function electrode material for next-generation metal-insulator-metal (MIM) capacitors, particularly for stabilizing the rutile phase of TiO₂ with a dielectric constant of 150. However, challenges such as stoichiometric variations in high-aspect-ratio structures and morphology degradation during reduction have limited its practical applications. To address these issues, a novel self-limiting deposition and etching in atomic-scale (SDEA) process is introduced. This approach combines atomic layer deposition (ALD) of MoO_a (2 < a < 3) using Mo + O₃, followed by atomic layer etching (ALE) of MoO₃ using H₂O. The process selectively removes MoO₃ through etching, leveraging the self-limiting nature of both reactions to achieve precise atomic-scale control over oxidation states without morphology degradation. MoO₂ films deposited using this method exhibit enhanced electrical performance, including a higher dielectric constant and reduced leakage current when employed as bottom electrodes in TiO₂-base metal-insulator-metal capacitors. This work provides a transformative solution for integrating MoO₂ into cutting-edge semiconductor devices, overcoming the limitations of existing deposition techniques. The SDEA process represents a significant advancement in material and process engineering, offering new possibilities for device miniaturization and performance enhancement.