While photomask prices continue to increase and their lifetime continues to be shortened due to molecular contamination, it is a key issue to understand the chemical mechanism of the mask damage caused by haze problem to save fabrication cost.  We show a unique method for in-situ Airborne Molecular Contamination, or AMC, measurement in the mask carrier mini-environment as well as the small volume confined under the pellicle protective film. 
Additionally, an ultimate solution to decontaminate the photomask and surrounding environment with a vacuum purging system shows preliminary positive results on the extension of photomask life time by elimination of the haze problem cause.