A semiconductor process is provided. A substrate is provided and then a to-be-etched layer is formed on the substrate. A patterned photoresist layer is formed on the to-be-etched layer. The to-be-etching layer is etched using a gaseous etchant to form a patterned layer. In the meantime, some of the gaseous etchant is condensed on the patterned photoresist layer and above the substrate after the etching process. Thereafter, a heat treatment process is performed to remove the condensed gaseous etchant. An ion implanting process is performed to form a doped region in the substrate. After the ion implanting process, the patterned photoresist layer is removed.