Minimizing interfacial defects and enhancing hybrid oxidation in HfAlOx MIOS structures via In-Situ plasma treatment for enhancing electrical properties

Abstract

Ternary oxides have realized controllable dielectric constant and band gap (E_g) and are widely applied in electronic devices. Unfortunately, defects in the insulating layer severely affect the electrical performance of the devices. In this research, metal-insulator-oxide semiconductor (MIOS) diodes were developed by introducing in-situ Ar/O₂ plasma treatment in the supercycle atomic layer deposition (ALD) process, for which high on/off ratios (>10⁴), low off-currents (10^–9 A cm^-2), and breakdown voltages up to 12.4 V were obtained. The correlation of the sequence of in-situ plasma treatment on the oxygen-related bonding in HfAlOx thin films was confirmed by XPS analysis. Introducing in-situ plasma can effectively enhance the formation of metals with oxygen bonding while suppressing the content of defect states generated by oxygen vacancies in the films, to optimize the interfacial properties. Compared with the untreated device (HAO), the plasma treatment has reduced the hysteresis phenomenon, significantly improves the on/off ratio by about 1 order of magnitude, and increases the breakdown voltage by 42.5%. The suitable conduction mechanisms of HfAlOx based MSIM diodes and their corresponding energy band diagrams are schematized from the findings. The effects of in-situ plasma on MIOS structures have been demonstrated and expanded functionality has been provided for the development of microelectronic devices, energy-saving and power device applications.