Devices and methods for holding an optical element with reduced stress in an optical column and while performing an out-of-column procedure on the element

Abstract

Methods and devices are disclosed for holding an optical element in an optical column with reduced stress (e.g., thermal stress) to the optical element. The devices and methods are especially useful for holding reflective optical elements in an optical column of an optical system used for extreme ultraviolet lithography. The devices allow the elements to be mounted and detached readily from the column. In an embodiment, the device includes multiple anchoring members that attach to respective locations on the optical element. The anchoring members are, in turn, mounted in a mounting frame by a releasable attachment mechanism. Each anchoring member has at least a compliant region configured to prevent transmission of stress to and from the optical element.