Gas-Source Chemical Vapor Deposition of Atomically Thin WS2 for LSI Device Applications

Growth behaviors of chemical vapor deposition (CVD) of WS2 by using gaseous precursors of WF6 and H2S will be presented. The WS2 crystal growth exhibited layer-by-layer mode where nucleation and lateral growth were thermally activated. An optimized growth condition allowed us to obtain WS2 crystal with a grain size larger than 3 mu m, which is the largest size ever reported for gas-source CVD grown transition-metal dichalcogenides (TMDs) without an alkali-metal promotor.