Patent ID: 8207504

Claim:
A system, comprising: a mask manipulator arranged to: receive an extreme ultra violet (EUV) pod that encloses an EUV mask, the EUV pod comprising an inner pod that is placed inside an outer pod, wherein the EUV pod is opaque to deep ultra violet (DUV) radiation; extract, in a highly clean environment, the EUV mask from the outer pod and the inner pod; and cover, in the highly clean environment, an upper face of the EUV mask with a protective cover that is at least partially transparent to DUV radiation; a scanner arranged to scan the EUV mask using DUV illumination provided by an optical DUV illuminator, while maintaining in the scanner an environment that has a cleanliness level that is below a tolerable EUV mask cleanliness level; and a transport system arranged to transport the EUV mask and the protective cover between the scanner and the mask manipulator, wherein the tolerable EUV mask cleanliness level does not exceed a cleanliness level of the highly clean environment.