Crystal orientation and near-interface structure of chemically vapor deposited MoS₂ films

Crystalline MoS₂ films were deposited on Si and graphite substrates using MoF₆ and H₂S as precursors. The crystal orientation and near-interface structure of the MoS₂ films were studied using transmission electron microscopy. In general, the preferred orientation of the (002) basal planes of the MoS₂ films with respect to the substrate surface changed from parallel to perpendicular with increased deposition temperature from 320 to 430 °C. At 430 °C, the basal planes were primarily oriented perpendicular to the Si substrate, except for the presence of a ∼5 nm interface region in which the basal planes were oriented in the parallel direction. The formation of this transitional region was also observed on the graphite substrate.