A pellicle mask assembly includes a mask, a pellicle frame, and a pellicle membrane. The pellicle frame has a bottom side attached to the mask, and a top side covered by the pellicle membrane. The pellicle frame includes a coating on its inner surface and the coating is configured to monitor a change of environment inside the pellicle mask assembly. In embodiments, the change of environment includes increased humidity and/or increased chemical ion density inside the pellicle mask assembly. Methods of making and using the pellicle mask assembly are also disclosed.