Role of temperature and plasma on low-pressure chemical vapor deposition of MoS₂ and WS₂

Two-dimensional transition metal dichalcogenides (TMDs) have attracted a wide range of research interest due to their remarkable electronic and optical properties. We investigate the effect of temperature and plasma on the nucleation density and uniformity of bulk to few layered MoS₂ and WS₂ grown by low pressure chemical vapor deposition (LP-CVD) on thermally oxidized silicon. Sulfur, MoO3 and WO3 solid precursors were used for the growth of the respective films. Characterization of the deposited samples was performed using Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Introduction of plasma results in an increased nucleation density, extended growth range, and greater film uniformity at the cost of smaller single-crystalline regions. By optimizing temperature and plasma characteristics, we provide a framework for large scale growth of uniform MoS₂ and WS₂ with plasma-enhanced LP-CVD.