Devices and methods for cooling optical elements in optical systems, including optical systems used in vacuum environments

摘要

Devices are disclosed that cool optical elements with which the devices are associated, most advantageously reflective optical elements such as mirrors and reflective reticles. The devices have especial utility for reducing deformation and other undesired thermal changes of the respective optical elements, such as optical elements used in extremely demanding optical systems such as used in microlithography systems, most notably EUVL systems. Many of the subject devices typically include a heat-receiving plate or analogous feature that receives heat radiated from the optical element across a gap between the optical element and the heat-receiving plate. Some devices include a plate-cooling device for removing heat from the heat-receiving plate. Other devices employ conduction of heat away from the optical element. Yet other devices employ a flowing heat-transfer medium for removing heat from the optical element. Certain devices also are configured to provide mechanical support for the respective optical elements, notably in a manner that limits deformation of the optical elements.