Microlithographic projection exposure apparatus and method of correcting optical wavefront deformations in such an apparatus

摘要

A microlithographic projection exposure apparatus includes a correction device configured to correct optical wavefront deformations. The correction device includes first and second optical elements and a drive mechanism configured to move the first and second optical elements between a first arrangement and a second arrangement. In the first arrangement the first optical element is an inner optical element having at least a portion that is arranged in a projection light path, and the second optical element is an outer optical element that is arranged completely outside the projection light path. In the second arrangement the second optical element is the inner optical element, and the first optical element is the outer optical element. The correction device further includes a temperature control device configured to modify a temperature distribution in the outer optical element.