Method of stripping a resist mask

摘要

A method for removing a used organic resist in a downstream ashing apparatus on a silicon semiconductor wafer in which water vapor is added to an oxygen plasma gas generated by microwaves. The addition of the water vapor lowers an activation energy of the ashing reaction and increases the reactive species generated in the plasma. Accordingly, the ashing rate is increased even at a wafer processing temperature as low as 150 DEG C. The addition of water vapor increases the ashing rate for a wide range of the percentage of water content, such as 5 to 80%, allowing easy control of the process. The lowered operating temperature prevents contamination of the semiconductor wafer. Since CF4 is not used the SiO2 layer is protected from being undesirably etched and the semiconductor characteristics do not deteriorate.