Self-isolating electrode deposition process using the area-selective MoO2 and MoO3 atomic layer deposition technique

The traditional patterning process for semiconductor devices typically involves multiple steps, including thin film deposition across the entire substrate, selective removal of unwanted regions through lithography and etching, and subsequent isolation. While area-selective deposition process has been employed to eliminate the need for lithography and etching, the isolation step remains essential. In this study, we suggest an innovative approach to achieve "self-isolation electrode formation" using MoO2 and MoO3 as electrode and inter-metallic insulator materials. In a single deposition batch and subsequent post-deposition annealing (PDA) process, deposited MoOx (x: 2∼3) thin films exhibited transformation into highly crystalline MoO2 and MoO3 with low crystallinity, depending on whether they were deposited on TiN or SiO2 surfaces. We conducted comprehensive analyses, including chemical and electrical characterizations, as well as first-principles calculations based on density-functional theory, to elucidate the underlying mechanisms responsible for the differential reduction and crystallization of MoOx thin films. Finally, we successfully demonstrated the formation of self-isolation electrodes within a vertical structure, accomplished through a single-step process involving MoOx deposition and subsequent PDA. This novel approach, built upon advanced area-selective deposition techniques, holds great promise for the development of state-of-the-art semiconductor devices.