• Mattinen, Miika Juhana
• King, Peter J.
• Leskelä, Markku Antero
• Meinander, Kristoffer
• Hatanpää, Timo Tapio
• Mizohata, Kenichiro
• Ritala, Mikko
• Sarnet, Tiina
• Khryashchev, Leonid
• Räisänen, Jyrki

Abstract

<p>Molybdenum disulfide (MoS2) is a semiconducting 2D material, which has evoked wide interest due to its unique properties. However, the lack of controlled and scalable methods for the production of MoS2 films at low temperatures remains a major hindrance on its way to applications. In this work, atomic layer deposition (ALD) is used to deposit crystalline MoS2 thin films at a relatively low temperature of 300 degrees C. A new molybdenum precursor, Mo(thd)(3) (thd = 2,2,6,6-tetramethylheptane-3,5-dionato), is synthesized, characterized, and used for film deposition with H2S as the sulfur precursor. Self-limiting growth with a low growth rate of approximate to 0.025 angstrom cycle(-1), straightforward thickness control, and large-area uniformity are demonstrated. Film crystallinity is found to be relatively good considering the low deposition temperature, but the films have significant surface roughness. Additionally, chemical composition as well as optical and wetting properties are evaluated. MoS2 films are deposited on a variety of substrates, which reveal notable differences in growth rate, surface morphology, and crystallinity. The growth of crystalline MoS2 films at comparably low temperatures by ALD contributes toward the use of MoS2 for applications with a limited thermal budget.</p>

Topics

• impedance spectroscopy
• surface
• molybdenum
• thin film
• chemical composition
• crystallinity
• atomic layer deposition