A system is disclosed. The system includes a cleaning device and a scanner device. The cleaning device is configured to clean a mask. The scanner device is coupled to the cleaning device and is configured to receive the mask, a reference image and a real-time image that is captured at the mask. The reference image includes at least one first mark image having a plurality of mapping marks on the mask. The real-time image includes at least one second mark image having the plurality of mapping marks on the mask. The scanner device is configured to map the at least one second mark image in the real-time image with the at least one first image in the reference image, when a lithography exposing process is performed. A method is also disclosed herein.