Heat sink dependency of mask in-plane displacement for extreme ultraviolet lithography

Heat transfer of radiation and conduction occurs simultaneously in an interface between mask rear surface and mask stage in an exposure tool due to surface roughness or gap caused by pin chucking. Mask stage acts as a heat sink to maintain mask performance during exposure of extreme ultraviolet (EUV). Clarification of the heat sink dependence on contact area gives useful guideline for designing an exposure system and for developing EUV mask and exposure tool. In this study, thermally induced in-plane displacement (IPD) of EUV mask in contact with heat sink of mask stage was predicted by simulation model.