Optical Projection System

Abstract

An optical projection unit includes first and second optical element modules. The first optical element module includes a first housing unit and a first optical element received within the first housing unit and having an optically used first region defining a first optical axis. The second optical element module is located adjacent to the first optical element module and includes a second optical element which defines a second optical axis of the optical projection unit. The first housing unit has a central first housing axis and an outer wall extending in a circumferential direction about the first housing axis. The first optical axis is laterally offset and/or inclined with respect to the first housing axis. The first housing axis is substantially collinear with the second optical axis.

1 .- 124 . (canceled) 
     
     
         125 . A support unit of a microlithography system, the support unit comprising:
 a housing configured to partly receive a light path;   an elongated first lens unit comprising a plurality of lenses; and   an elongated second lens unit comprising a plurality of lenses,   wherein:
 the housing receives a first optical sub-system of the microlithography system; 
 the first optical sub-system comprises a first reflective element; 
 the housing comprises a first interface, a second interface and a third interface; 
 the first interface supports the elongated first lens unit; 
 the second interface supports the elongated second lens unit; 
 the third interface supports an optical unit of the microlithography system; 
 the optical unit of the microlithography system comprises a second optical subsystem which comprises an actively controlled second reflective element; and 
 the housing substantially bears the load of the elongated first and second lens units. 
   
     
     
         126 . The support unit of  claim 125 , wherein the optical unit is configured to actively position the second reflective element during operation of the microlithography system. 
     
     
         127 . The support unit of  claim 125 , wherein the optical unit is configured to actively adjust a position of the further reflective element under control of a control device and based on information representative of an actual imaging quality of the microlithography system. 
     
     
         128 . The support unit of  claim 125 , wherein:
 the first reflective element is configured to direct the light path towards the further optical sub-system of the optical unit;   the second reflective element is an outermost element of the second optical sub-system of the optical unit; and   the second reflective element is configured to direct the light path back toward the optical sub-system received within the housing.   
     
     
         129 . The support unit according to  claim 125 , wherein the first optical sub-system is mounted to the housing. 
     
     
         130 . The support unit according to  claim 125 , wherein the housing comprises at least one member selected from the group consisting of a light tight housing and a gas tight housing. 
     
     
         131 . The support unit of  claim 125 , wherein:
 the first interface comprises a planar first interface surface; and   the second interface comprises a planar second interface surface which is parallel to the planar first interface surface.   
     
     
         132 . The support unit of  claim 125 , wherein the optical unit of the microlithography system is a third lens unit of the microlithography system, and the third lens unit comprises a lens. 
     
     
         133 . The support unit of  claim 125 , wherein:
 the first interface has a planar first interface surface; and   the third interface has a planar third interface surface which is inclined with respect to the planar first interface surface.   
     
     
         134 . The support unit of  claim 125 , wherein:
 the first interface comprises a planar first interface surface; and   the housing comprises a fourth interface comprising a planar fourth interface surface which is coplanar with the planar first interface surface.   
     
     
         135 . The support unit of  claim 125 , wherein the housing comprises a fifth interface comprising at least one member selected from the group consisting of a reference interface and a rest interface. 
     
     
         136 . The support unit of  claim 125 , wherein the housing is monolithic. 
     
     
         137 . The support unit of  claim 125 , wherein the housing comprises a plurality of separate housing components. 
     
     
         138 . The support unit of  claim 125 , wherein the housing comprises a material having at least one property selected from the group consisting of a high modulus of elasticity, a high thermal conductivity, and a low thermal expansion coefficient. 
     
     
         139 . The support unit of  claim 125 , wherein the housing comprises a ceramic material. 
     
     
         140 . The support unit of  claim 125 , wherein the housing comprises SiC. 
     
     
         141 . The support unit of  claim 125 , wherein the housing comprises ceramically bonded sub-sections. 
     
     
         142 . The support unit of  claim 125 , wherein the housing via at least one process selected from the group consisting of a low shrinkage near-net-shape casting process and a low shrinkage near-net-shape reaction infiltration process. 
     
     
         143 . The support unit of  claim 125 , wherein the first interface comprises an air bearing unit. 
     
     
         144 . An optical projection system, comprising:
 a housing configured to partly receive a light path;   an elongated first lens unit comprising a plurality of lenses;   an elongated second lens unit comprising a plurality of lenses;   a first optical sub-system comprising a first reflective element; and   a second optical sub-system comprising an actively controlled second reflective element,   wherein:
 the housing substantially bears the load of the elongated first and second lens units; 
 the housing receives the first optical sub-system; 
 the housing comprises a first interface, a second interface and a third interface; 
 the first interface supports the elongated first lens unit; 
 the second interface supports the elongated second lens unit; 
 the third interface supports the second optical sub-system; 
 the elongated first lens unit receives a first part of the light path, 
 the elongated second lens unit receives a second part of the light path, and 
 the housing receives a third part of the light path; 
 an optical unit comprises the second optical sub-system 
 the optical unit receives a fourth part of the light path; and 
 the optical projection system is a microlithographic optical projection system. 
   
     
     
         145 . The optical projection system according to  claim 144 , wherein during use of the microlithography system exposure light travels along the light path in a sequence along the first, third, fourth and second part of the light path. 
     
     
         146 . The optical projection system of  claim 144 , wherein:
 the first lens unit has a first optical axis; and   the second lens unit has a second optical axis that is parallel to the first optical axis, collinear with the first optical axis, or inclined to the first optical axis;   
     
     
         147 . The optical projection system according to  claim 144 , wherein
 the first lens unit has an optical axis; and   the second optical sub-system has an optical axis that is inclined with respect to the optical axis of the first lens unit.   
     
     
         148 . An apparatus, comprising:
 an optical projection system according to  claim 144 ,   wherein the apparatus is an optical exposure configured to transfer an image of a pattern formed on a mask onto a substrate.