[H-3] Characterization II: Low Dimensional Devices and Materials

[H-3-01] Revealing the role of oxygen on defect formation of MoS₂ by combining thermal desorption spectroscopy and atomic layer deposition

〇Shuhong Li¹, Tomonori Nishimura¹, Mina Maruyama², Susumu Okada², Kosuke Nagashio¹ (1. Univ. of Tokyo (Japan), 2. Univ. of Tsukuba (Japan))

Presentation style: On-site (in-person)

https://doi.org/10.7567/SSDM.2022.H-3-01

The stability of MoS2 is critical for device application, while no capable method is reported to trace the atomic scale defects for MoS2 on insulating SiO2/Si substrate. Herein, the defect formation of MoS2 was quantitatively investigated from the viewpoint of sulfur desorption by thermal desorption spectroscopy and also traced through defect selective oxide deposition by ALD. With annealing MoS2 even at ultra-high vacuum, the adsorbed oxygen molecule assists the sulfur atom to dissociate from MoS2 and thus defects are formed, suggesting that removal of adsorbed oxygen is key to avoiding degradation of MoS2