Molybdenum disulfide (MoS₂) is a promising 2D semiconductor material for low-power electronics due to its excellent electrical properties and compatibility with conventional processes. In this study, MoS₂ thin films deposited by RF sputtering were etched using Cl₂/Ar plasma in an ICP system. The effects of Cl₂ gas ratio, RF power, and process pressure on etch rate and MoS₂/SiO₂ selectivity were investigated. Optimal results were obtained at 25% Cl₂, achieving ~38 nm/min etch rate and selectivity of 3.0. Increased source power improved both etch rate and selectivity, while higher bias power enhanced etching but reduced selectivity due to stronger ion bombardment. XPS analysis confirmed Mo－Cl and S－Cl bond formation after etching, indicating chemical reactions and some by-product residue. These results provide insights into optimized plasma etching of sputtered MoS₂ films for advanced 2D device fabrication
