Smoothing effects of postlithography plasma treatments on 22-nm lines and spaces are evaluated for two types of extreme ultraviolet photoresists, using five different plasma processes (Ar, , HBr, , and ). Experimental results indicate a reduction in linewidth roughness of about 10% by using an plasma smoothing process. This smoothing process is mainly triggered by the synergy of vacuum ultraviolet photons and reactive species during the plasma treatment. Moreover, the smoothing process is dependent on the resist composition and the pattern dimensions. This paper shows the impact of different plasma conditions on roughness reduction for 22-nm lines.