Area-selective atomic layer deposition of MoS${}_2$ using simultaneous deposition and etching characteristics of MoCl${}_5$

A novel selective atomic layer deposition (ALD) process for depositing MoS${}_2$ using MoCl${}_5$ and H${}_2$S precursors is proposed. On the surface of SiO${}_2$, the prolonged introduction of MoCl${}_5$ vapor by increasing the MoCl${}_5$ pulsing time rapidly suppresses the subsequent MoS${}_2$ growth due to the intense self-etching effect of MoCl${}_5$, that is, the detachment of weakly bonded surface adsorbates (MoCl${}_x$*). In contrast, the surface of Al allows more facile adsorption of MoCl${}_5$ than in the case of the SiO${}_2$ surface, and thus effectively compensates for the reduced deposition rate. By optimizing the MoCl${}_5$ pulsing time, the self-aligned growth of MoS${}_2$ on predefined Al (5 nm) patterns (circular and letter patterns) on a SiO${}_2$ substrate with a negligible selectivity loss is demonstrated. (© 2021 Wiley‐VCH GmbH)