(Invited) Thermodynamic Modeling of W-C-O-H-S System for Controlled Growth of WS2 Atomic Layers by True CVD. (18th April 2017)

• Record Type: Journal Article
• Authors: Dhar, Sukanya; Lalithambika, Anjali; Kumar V, Kranthi; Raghavan, Srinivasan
• Is Part Of: ECS transactions. Volume 77:Number 2(2017)
• Page Start: 49
• Page End: 59
• Publication Date: 2017-04-18
• Subjects: Electrochemistry -- Periodicals; Electrochemistry; Periodicals; Electronic journals; Electronic journal; 541.37
• DOI: 10.1149/07702.0049ecst
• Languages: English
• ISSNs: 1938-5862

Abstract

Abstract : A detailed thermodynamic analysis of the solid and gas phases for the W-C-O-H-S system, used for large area chemical vapor deposition (CVD) of WS2, is presented and compared with experimental results. Given the multivariable nature of the problem, good agreement is observed. CVD phase diagrams which predict parameter windows in which pure WS2 can be synthesized have been provided for important gas phase chemistries. Pure H2 as a carrier gas is shown to facilitate the largest contamination free process window. The ability to predict completely different outcomes on using Ar versus (Ar+H2 ) mixture or pure H2 as the carrier gas highlights the importance of such thermodynamic modelling. Comparison of these results with a similar system Mo-C-O-H-S has been performed, which indicates some differences in stability windows, but follows similar trends.