Ti‐capped Al–Si films are more susceptible to post‐etch corrosion than uncapped Al–Si films. The extent of corrosion of Ti‐capped films is related to post‐etch treatment. Various post‐etch treatments to reduce chlorine concentration are evaluated by x‐ray fluorescence analysis. Results of single‐ and multiple‐step treatment, such as baking, partial resist stripping in oxygen plasma in the exit chamber, water rinse, and resist partial stripping followed by wet stripping are presented. A method to estimate the surface concentration of chlorine in atoms/cm2is described; the chlorine concentration in most cases is less than 5×1015atoms/cm2.