Projection objective of a microlithographic projection exposure apparatus

Abstract

A projection objective of a microlithographic projection exposure apparatus has a plurality of optical elements, for example lenses or mirrors. The objective furthermore includes an actuator for exerting a mechanical force that deforms a selected optical element of the projection objective. A manipulator modifies the spatial position of one of the optical elements as a function of the force exerted by the actuator.

1 . An objective, comprising:
 a) a plurality of optical elements,   b) at least one actuator configured to exert a mechanical force that deforms a first optical element of the plurality of optical elements such that the first optical element is deformed and changes its spatial position, wherein a change of the spatial position of the first optical element causes an impairment of the imaging properties of the objective,   c) at least one manipulator configured to modify the spatial position of a second optical element of the plurality of optical elements without deforming the second optical element when the manipulator is driven,   d) a device adapted to drive the at least one manipulator such that the second optical element changes its spatial position in a way that reduces the impairment of the imaging properties,   wherein the objective is designed to be used as projection objective of a microlithographic projection exposure apparatus.   
     
     
         2 . The objective of  claim 1 , wherein the device is adapted to automatically modify the spatial position of the second optical element. 
     
     
         3 . The objective of  claim 1 , wherein the at least one manipulator is configured to tilt the second optical element about an axis that is substantially perpendicular to a symmetry axis of the second optical element. 
     
     
         4 . The objective of  claim 1 , wherein the at least one manipulator is configured to displace the second optical element in a plane that is substantially perpendicular to a symmetry axis of the second optical element. 
     
     
         5 . The objective of  claim 1 , wherein the second optical element is the first optical element. 
     
     
         6 . The objective of  claim 1 , wherein the at least one actuator is configured to be fluidically actuated. 
     
     
         7 . The objective of  claim 1 , wherein the at least one manipulator is configured to be fluidically actuated. 
     
     
         8 . The objective of  claim 6 , wherein the at least one manipulator is configured to be fluidically actuated, and wherein the at least one actuator and the at least one manipulator are connected to a fluidic pressure system which is configured to fluidically actuate the at least one actuator and the at least one manipulator simultaneously. 
     
     
         9 . The objective of  claim 8 , wherein the fluidic pressure system is configured such that changes in the fluid pressure applied to the at least one actuator result in changes in the fluid pressure applied to the at least one manipulator. 
     
     
         10 . The objective of  claim 9 , wherein the at least one manipulator is connected in series with the at least one actuator in the fluidic pressure system. 
     
     
         11 . The objective of  claim 1 , wherein the device adapted to drive the at least one manipulator comprises a regulator configured to regulate spatial position changes of the second optical element as a function of the changes of the spatial position of the first optical element caused by the actuator. 
     
     
         12 . The objective of  claim 1 , wherein the device adapted to drive the at least one manipulator comprises a controller configured to control the spatial position changes of the second optical element as a function of the changes of the spatial position of the first optical element caused by the actuator. 
     
     
         13 . The objective of  claim 6 , further comprising a pressure line, which leads to the at least one actuator, and a resilient compensating element, which is integrated into the pressure line, wherein deformations of the compensating element caused by pressure fluctuations are transmitted via a transmission element to the at least one manipulator. 
     
     
         14 . The objective of  claim 1 , wherein the at least one manipulator engages directly on the second optical element. 
     
     
         15 . The objective of  claim 1 , wherein the at least one manipulator engages on a mounting containing the second optical element. 
     
     
         16 . The objective of  claim 1 , wherein the at least one manipulator engages on a frame on which a mounting containing the second optical element is supported. 
     
     
         17 . The objective of  claim 6 , comprising a pressure line, which leads to the at least one actuator, and a plurality of resilient compensating elements, which are integrated in the pressure line and are arranged relative to one another so that deformation forces in the compensating elements caused by pressure changes mutually compensate at least substantially. 
     
     
         18 . The objective of  claim 17 , wherein two compensating elements are connected together to a pressure feed line and together to a pressure discharge line such that they are arranged diametrically opposite each other. 
     
     
         19 . The objective of  claim 1 , wherein the first and second optical elements are mirrors. 
     
     
         20 . An objective, comprising:
 a) a plurality of optical elements,   b) at least one actuator configured to exert a mechanical force that deforms a first optical element of the plurality of optical elements,   c) at least one manipulator configured to modify the spatial position of a second optical element of the plurality of optical elements when the manipulator is driven,   d) a controller adapted to drive the at least one manipulator as a function of the forces exerted by the at least one actuator if the at least one actuator is actuated,
 wherein the objective is a projection objective designed to be used in a microlithographic projection exposure apparatus. 
   
     
     
         21 . The objective of  claim 20 , wherein the controller is adapted to drive the at least one manipulator synchronously with an actuation of the at least one actuator. 
     
     
         22 . The objective of  claim 20 , wherein the controller is in configured to be in communication with a look up table comprising a first set of data related to positions of the at least one manipulator and a second set of data related to forces exerted by the at least one actuator. 
     
     
         23 . The objective of  claim 20 , wherein the first and second optical elements are mirrors.