Soft Sputtering of Large-Area 2D MoS₂ Layers Using Isolated Plasma Soft Deposition for Humidity Sensors

2D transition-metal dichalcogenides are emerging as key materials for next-generation semiconductor technologies owing to their tunable bandgaps, high carrier mobilities, and exceptional surface-to-volume ratios. Among them, molybdenum disulfide (MoS₂) has garnered significant attention. However, scalable wafer-level deposition methods that enable uniform layer-controlled synthesis remain a critical challenge. In this paper, a novel fabrication approach-isolated plasma soft deposition (IPSD) followed by sulfurization-for the scalable production of 2D MoS₂ with precise layer control is introduced. The IPSD system employs a scanning-based deposition method combined with plasma surface pretreatment, achieving large-area, high-quality 2D MoS₂ layers. Comprehensive characterizations using Raman, UV-vis, and photoluminescence spectroscopy, and transmission electron microscopy confirmed the successful synthesis of crystalline mono- to tetralayer 2D MoS₂ on 6-inch SiO₂/Si substrates. Furthermore, respiration sensors fabricated using the IPSD-grown 2D MoS₂ layers demonstrated fast response times (≈1 s) and high response to relative humidity levels between 30% and 60%. This study offers significant advancements in the scalable synthesis of 2D MoS₂ and opens new avenues for its application in advanced sensing and electronic devices.