Investigation of image placement errors in Extreme Ultraviolet Lithography masks

Extreme Ultraviolet Lithography (EUVL) is one of the principal carriers for the IC production at sub-45 nm technology nodes. One of the key problems to be solved before EUVL can be commercialized is the control of the image placement errors during the EUVL mask fabrication. In this paper, EUVL mask fabrication process has been analyzed and the image placement errors induced during the EUVL mask fabrication process were investigated. With the implementation of an electrostatic chuck at both e-beam tool and exposure tool chucking, the image placement errors due to the mask fabrication can be well controlled.