Optical Element Unit And Method Of Supporting An Optical Element

Abstract

There is provided an optical element unit comprising an optical element, a connector element, and an optical element holder. The optical element has a plane of main extension as well as an outer circumference and defines a radial direction. The connector element connects the optical element and the optical element holder, the connector element having a first connector part connected to the optical element at the outer circumference and a second connector part connected to the optical element holder. The first connector part and the second connector part are connected via at least one coupling part, the coupling part being compliant in the radial direction and substantially preventing rotation between the first connector part and the second connector part in a plane substantially parallel to the plane of main extension.

1 .- 25 . (canceled) 
     
     
         26 . An optical element unit, the optical element unit comprising:
 an optical element;   a connector element; and   an optical element holder having a plane of main extension and an outer circumference and defining a radial direction,   wherein:
 the connector element connects the optical element and the optical element holder; 
 the connector element comprises a first connector part connected to the optical element at the outer circumference; 
 the connector element comprises a second connector part connected to the optical element holder; 
 the first and second connector parts are connected via a coupling part; 
 the coupling part is compliant in the radial direction; 
 the first connector part comprises a contact part with a contact element; 
 the first connector part is connected to the optical element at a contact location via the contact element; and 
 the contact location extends over 5% to 10% of the outer circumference of the optical element. 
   
     
     
         27 . The optical element unit of  claim 26 , wherein the contact location extends over 7% to 8.5% of the outer circumference of the optical element. 
     
     
         28 . The optical element unit of  claim 26 , wherein at least one member selected from the group consisting of the contact part and the contact element is adapted to a curvature of the optical element at the contact location. 
     
     
         29 . The optical element unit of  claim 26 , wherein the first connector part comprises a plurality of contact elements, and the contact elements are spaced apart along the outer circumference of the optical element. 
     
     
         30 . The optical element unit of  claim 26 , wherein the first connector part is connected to the optical element via at least one member selected from the group consisting of an adhesive bond, a positive connection and a frictional connection. 
     
     
         31 . The optical element unit of  claim 26 , wherein
 the optical element unit comprises a plurality of connector elements;   the connector element defines part of the plurality of connector elements;   the connector elements have substantially equal design; and   the connector elements connect the optical element and the optical element holder.   
     
     
         32 . The optical element unit of  claim 31 , wherein the connector elements are substantially equally distributed over the outer circumference of the optical element. 
     
     
         33 . An optical exposure apparatus configured to transfer an image of a pattern formed on a mask onto a substrate, the optical exposure apparatus comprising:
 an illumination system configured to provide light of a light path so that, during use of the optical exposure apparatus, the mask is located within the light path; and   an optical projection system located within the light path so that, during use of the optical exposure apparatus, the optical projection system is within the light path between the mask location and the substrate,   wherein the illumination system comprises an optical element unit according to  claim 26 .   
     
     
         34 . The optical exposure apparatus of  claim 33 , wherein the plane of main extension is inclined with respect to a horizontal plane. 
     
     
         35 . An optical exposure apparatus configured to transfer an image of a pattern formed on a mask onto a substrate, the optical exposure apparatus comprising:
 an illumination system configured to provide light of a light path so that, during use of the optical exposure apparatus, the mask is located within the light path; and   an optical projection system located within the light path so that, during use of the optical exposure apparatus, the optical projection system is within the light path between the mask location and the substrate,   wherein the optical projection system comprises an optical element unit according to  claim 26 .   
     
     
         36 . The optical exposure apparatus of  claim 35 , wherein the plane of main extension is inclined with respect to a horizontal plane. 
     
     
         37 . A method of supporting an optical element, the method comprising:
 connecting the optical element and the optical element holder via a connector element, wherein:
 the optical element has a plane of main extension as well as an outer circumference and defining a radial direction; 
 the connector element is compliant in the radial direction; 
 the connector part comprises a first connector part connected to the optical element at the outer circumference; 
 the first connector part comprises a contact part comprising a contact element; 
 the first connector part is connected to the optical element at a contact location via the at least one contact element; and 
 the contact location extends over 5% to 10% of the outer circumference of the optical element. 
   
     
     
         38 . The method of  claim 37 , wherein the contact location extends over 7% to 8.5% of the outer circumferences of the optical element. 
     
     
         39 . The method of  claim 37 , wherein connecting the optical element and the optical element holder comprises adhesively bonding the first connector part to the optical element. 
     
     
         40 . The method of  claim 37 , wherein:
 a plurality of connector elements is provided;   the connector element defines part of the plurality of connector elements, the connector elements have substantially equal design; and   
       the method further comprises connecting the optical element and the optical element holder via the connector elements. 
     
     
         41 . The method of  claim 40 , wherein the connector elements are substantially equally distributed over the outer circumference of the optical element. 
     
     
         42 . The method of  claim 37 , wherein the method provides an optical element unit. 
     
     
         43 . The method of  claim 42 , further comprising:
 using an illumination system to illuminate a mask, the illumination system supporting the optical element; and   using a projection optical system to image the mask onto a substrate.   
     
     
         44 . The method according to  claim 43 , wherein supporting the optical element comprises supporting the optical element so that the plane of main extension is inclined with respect to a horizontal plane. 
     
     
         45 . The method of  claim 44 , further comprising:
 using an illumination system to illuminate a mask; and   using a projection optical system to image the mask onto a substrate, the projection optical system supporting the optical element.   
     
     
         46 . The method of  claim 45 , wherein supporting the optical element comprises supporting the optical element so that the plane of main extension is inclined with respect to a horizontal plane. 
     
     
         47 . An optical element unit comprising:
 an optical element;   a connector element; and   an optical element holder having a plane of main extension as well as an outer circumference and defining a radial direction,   wherein:
 the connector element connects the optical element and the optical element holder; 
 the connector element comprises a first connector part connected to the optical element at the outer circumference; 
 the connector element comprises a second connector part connected to the optical element holder; 
 the first and second connector parts are connected via a coupling part; 
 the coupling part is compliant in the radial direction; 
 the first connector part comprises a contact part comprises a plurality of contact elements; and 
 the first connector part is connected to the optical element at a contact location via the plurality of contact elements. 
   
     
     
         48 . The optical element unit of  claim 47 , wherein the contact elements are spaced apart along the outer circumference of the optical element to define a gap between two neighboring contact elements. 
     
     
         49 . The optical element unit of  claim 48 , wherein, in an area of the gap, no contact exists between the optical element and the contact part. 
     
     
         50 . The optical element unit of  claim 47 , wherein the contact location extends over 5% to 10% of the outer circumference of the optical element. 
     
     
         51 . The optical element unit of  claim 47 , wherein at least one member selected from the group consisting of the contact part and a contact element is adapted to a curvature of the optical element at the contact location. 
     
     
         52 . The optical element unit of  claim 47 , wherein the first connector part is connected to the optical element via at least one member selected from the group consisting of an adhesive bond at each one of the plurality of contact elements. 
     
     
         53 . The optical element unit of  claim 47 , wherein:
 the optical element unit comprises a plurality of connector elements;   the connector element defines part of the plurality of connector elements;   the connector elements of the plurality of connector elements have equal design; and   the connector elements connect the optical element and the optical element holder.   
     
     
         54 . The optical element unit of  claim 53 , wherein the connector elements are substantially equally distributed over the outer circumference of the optical element. 
     
     
         55 . An optical exposure apparatus configured to transfer an image of a pattern formed on a mask onto a substrate, the optical exposure apparatus comprising:
 an illumination system configured to provide light of a light path so that, during use of the optical exposure apparatus, the mask is located within the light path; and   an optical projection system located within the light path so that, during use of the optical exposure apparatus, the optical projection system is within the light path between the mask location and the substrate,   wherein the illumination system comprises an optical element unit according to  claim 47 .   
     
     
         56 . The optical exposure apparatus of  claim 55 , wherein the plane of main extension is inclined with respect to a horizontal plane. 
     
     
         57 . An optical exposure apparatus configured to transfer an image of a pattern formed on a mask onto a substrate, the optical exposure apparatus comprising:
 an illumination system configured to provide light of a light path so that, during use of the optical exposure apparatus, the mask is located within the light path; and   an optical projection system located within the light path so that, during use of the optical exposure apparatus, the optical projection system is within the light path between the mask location and the substrate,   wherein the optical projection system comprises an optical element unit according to  claim 47 .   
     
     
         58 . The optical exposure apparatus of  claim 57 , wherein the plane of main extension is inclined with respect to a horizontal plane.