Abstract: Apparatus for semiconductor device fabrication, includes at least one lithography station, which is adapted to project a pattern of radiation from a mask onto a semiconductor wafer. A mask cleaning station is adapted to receive the mask from the at least one lithography station, to clean the mask so as to remove a contaminant therefrom, and so that the cleaned mask may be returned to the at least one lithography station. A robot is adapted to convey the mask between the at least one lithography station and the mask cleaning station. An enclosure contains the at least one lithography station, the mask cleaning station and the robot, so that the mask is conveyed between the at least one lithography station and the mask cleaning station without human contact and without exposure to ambient air.