Abstract: A method for swapping an optical system, such as a DUV mirror, of a projection exposure apparatus, comprises: a) raising the optical system along a centre axis of the optical system so that mount struts of the optical system pass out of contact with frame struts of a frame carrying the optical system; b) rotating the optical system about the centre axis so that the mount struts are arranged between the frame struts; c) lowering the optical system along the centre axis; and d) shifting the optical system perpendicularly to the centre axis so that the optical system is moved out of a housing.

Abstract: An optical system for a projection exposure apparatus comprises an optical element and a mount, which carries the optical element. The mount comprises an outer ring, in which the optical element is accommodated at least in portions. The outer ring comprises securing portions which are cohesively connected to the optical element. The securing portions are pivotably connected to the outer ring with the aid of joint portions. The mount comprises a tool interface for releasably securing a tool for swapping the optical system from an illumination optical unit.

Abstract: A bipod for adjusting an optical element of an optical system for a projection exposure apparatus, having a mechanism which is couplable to the optical element to adjust the optical element, a base portion, a first tower portion extending out of the base portion, and a second tower portion different from the first tower portion and extending out of the base portion. The mechanism is between the first and second tower portions. The first and second tower portions are connected to each other facing away from the base portion to increase the stiffness of the bipod.

Abstract: A component for a projection exposure apparatus for semiconductor lithography, comprises an optical element and an actuator, which are force-fittingly connected to each other. The actuator at least locally deforms the optical element. The actuator can be configured to minimize the loss in rigidity at the peripheries delimiting the actuator on the imaging quality. A method for designing a component of projection exposure apparatus is provided.

Abstract: A method for swapping an optical system, such as a DUV mirror, of a projection exposure apparatus, comprises: a) raising the optical system along a centre axis of the optical system so that mount struts of the optical system pass out of contact with frame struts of a frame carrying the optical system; b) rotating the optical system about the centre axis so that the mount struts are arranged between the frame struts; c) lowering the optical system along the centre axis; and d) shifting the optical system perpendicularly to the centre axis so that the optical system is moved out of a housing.

Abstract: A module for a projection exposure apparatus for semiconductor lithography includes at least one optical element arranged in a holder. At least one spacer is arranged between the holder and a further holder or a main body. The spacer is designed to semi-actively vary its extent. A method for positioning at least one holder in a projection exposure apparatus for semiconductor lithography includes using a semi-active spacer is to position the holder.