Wafer-scale growth of MoS₂ thin films by atomic layer deposition

The wafer-scale synthesis of MoS₂ layers with precise thickness controllability and excellent uniformity is essential for their application in the nanoelectronics industry. Here, we demonstrate the atomic layer deposition (ALD) of MoS₂ films with Mo(CO)₆ and H₂S as the Mo and S precursors, respectively. A self-limiting growth behavior is observed in the narrow ALD window of 155-175 °C. Long H₂S feeding times are necessary to reduce the impurity contents in the films. The as-grown MoS₂ films are amorphous due to the low growth temperature. Post-annealing at high temperatures under a H₂S atmosphere efficiently improves the film properties including the crystallinity and chemical composition. An extremely uniform film growth is achieved even on a 4 inch SiO₂/Si wafer. These results demonstrate that the current ALD process is well suited for the synthesis of MoS₂ layers for application in industry.