Catadioptric objective comprising two intermediate images

Abstract

An objective comprising axial symmetry, at least one curved mirror and at least one lens and two intermediate images. The objective includes two refractive partial objectives and one catadioptric partial objective. The objective includes a first partial objective, a first intermediate a image, a second partial objective, a second intermediate image, and a third partial objective. At least one of the partial objectives is purely refractive. One of the partial objectives is purely refractive and one is purely catoptric.

1. An objective comprising axial symmetry, at least one curved mirror and at least one lens and two intermediate images. 
     
     
       2. An objective according to  claim 1  comprising two refractive partial objectives and one catadioptric partial objective. 
     
     
       3. An objective according to  claim 1  comprising
 a first partial objective,  
 a first intermediate image,  
 a second partial objective,  
 a second intermediate image,  
 a third partial objective,  
 wherein at least one of said partial objectives is purely refractive.  
 
     
     
       4. An objective according to  claim 1  comprising at least
 a first partial objective,  
 an intermediate image,  
 a second partial objective,  
 one of said partial objectives being purely refractive and one being purely catoptric.  
 
     
     
       5. An objective according to  claim 1 , flintier  further comprising a partial objective with two opposing concave mirrors with central bores, and with an optical axis, said concave mirrors being arranged axially symmetric with respect to said optical axis, their concave surfaces facing each other. 
     
     
       6. An objective according to claim  5 , wherein each of said concave mirrors has a vertex situated on said optical axis, and wherein each of said intermediate images has a maximum image height and is given on a surface with a piercing point on said optical axis, and at least one of said vertici is distant from at least one of said piercing points by a distance less than the maximum image height of the image having said piercing point. 
     
     
       7. An objective according to  claim 5 , wherein at least one lens is arranged in the beam path between the two concave mirrors. 
     
     
       8. An objective according to  claim 7 , herein  wherein said at least one lens has negative refractive power. 
     
     
       9. An objective according to  claim 5 , wherein said concave mirrors have central openings with a radius, each of said radii being no greater than 1.5 times the maximum image height of the neighboring intermediate image. 
     
     
       10. An objective according to  claim 5 , wherein each of the radii of said central openings is less than 25% of the maximum light beam height at said concave mirror. 
     
     
       11. An objective according to  claim 5 , wherein the light beam has a chief ray height at each of the bores, which is of equal value but opposite sign at the two bores. 
     
     
       12. An objective according to  claim 1 , wherein a first refractive partial objective,
 a partial objective comprising at least one mirror, and  
 a second refractive partial objective are arranged in sequence.  
 
     
     
       13. An objective according to claim  1    12 , wherein at least one lens of said refractive partial objectives has an aspheric surface. 
     
     
       14. An objective according to claim  1    12 , wherein at least one of said partial objectives comprises a diffractive optical element. 
     
     
       15. An objective according to claim  1    12 , wherein said partial objective comprising at least one mirror has a magnification ratio in the range between −1/0.7 and −1/1.3. 
     
     
       16. An objective according to  claim 12 , wherein the first refractive partial objective has a magnification ratio of −1/3 to −1/8. 
     
     
       17. An objective according to  claim 12 , wherein the second refractive partial objective has a magnification ratio of −1/0.8 to −1/2. 
     
     
       18. An objective according to claim  1    12 , wherein at least one of the first and second refractive partial objectives consists of a first positive lens group, a negative lens group and a second positive lens group. 
     
     
       19. An objective according to claim  1    18 , wherein said negative lens group comprises at least two negative menisci, their concave surfaces facing each other. 
     
     
       20. An objective according to  claim 18 , wherein at least one of said first and second positive lens groups comprises at least four positive lenses. 
     
     
       21. An objective according to  claim 1 , wherein all lenses contained are made of the same material, preferably a fluoride crystal. 
     
     
       22. An objective according to  claim 4 , wherein lenses are made from at least two different fluorides. 
     
     
       23. An objective according to  claim 1 , wherein the image field is an off-axis ring sector. 
     
     
       24. An objective according to claim  1    3 , wherein the first partial objective has a pupil plane and a central obscuration device is located near said pupil plane. 
     
     
       25. An objective according to claim  1    3 , wherein at least one of the refractive partial objectives has at least a first lens group and a second lens group, one of them having lesser lens diameters. 
     
     
       26. An objective according to claim  14    25 , wherein the at least one aspherical lens surface is on a lens of the lens group with lesser lens diameters. 
     
     
       27. An objective according to claim  1    3 , wherein the third partial objective has at least one positive concave air lens near its pupil plane, namely located at a distance from the second intermediate image of between 25% and 75% of the length of this partial objective. 
     
     
       28. An objective according to claim  1    3 , wherein the image side partial objective has two first lenses subsequent to the second intermediate image, which are menisci concave on the side of the intermediate image, and two last lenses adjacent to the image, which are meniscus concave on the side of the image. 
     
     
       29. An objective according to  claim 1 , wherein the image side  partial objective arranged at an image side has a pupil plane and at least one lens arranged at a distance from the image plane of between 25% and 75% of the length of the image side  said partial objective is a meniscus concave toward the pupil plane. 
     
     
       30. A microscope comprising an objective according to  claim 1 . 
     
     
       31. A microlithographic projection exposure apparatus comprising a projection objective according to  claim 1 . 
     
     
       32. Use of a projection  an objective according to  claim 1  for microlithographic projection exposure. 
     
     
       33. Method of microlithographic structuring of a substrate comprising the steps of illuminating a mask with VUV light and projecting an image of said mask onto said substrate through a projection  an objective according to  claim 1 . 
     
     
       34. An objective according to claim  6    5 , wherein at least one lens is arranged in the beam path between the two concave mirrors. 
     
     
       35. An objective according to  claim 15 , wherein the first refractive partial objective has a magnification ratio of −1/3 to −1/8. 
     
     
       36. An objective according to  claim 15 , wherein the second refractive partial objective has a magnification ratio of −1/0.8 to −1/2. 
     
     
       37. An objective according to  claim 16 , wherein the second refractive partial objective has a magnification ratio of −1/0.8 to −1/2. 
     
     
       38. An objective according to  claim 19 , wherein at least one of said first and second positive lens groups comprises at least four positive lenses. 
     
     
       39. An objective according to  claim 25 , wherein the at least one aspherical lens surface is on a lens of the lens group with lesser lens diameters. 
     
     
       40. A microlithography projection exposure apparatus comprising a projection objective according to  claim 3 . 
     
     
       41. Use of a projection objective according to  claim 3  for microlithography projection exposure. 
     
     
       42. Method of microlithographic structuring of a substrate comprising the steps of illuminating a mask with VUV light and projecting an image of said mask onto said substrate through a projection objective according to  claim 3 . 
     
     
       43. A microlithographic projection exposure apparatus comprising a projection objective according to  claim 4 . 
     
     
       44. Use of a projection objective according to  claim 4  for microlithographic projection exposure. 
     
     
       45. Method of microlithographic structuring of a substrate comprising the steps of illuminating a mask with VUV light and projecting an image of said mask onto said substrate through a projection objective according to  claim 4 . 
     
     
       46. A microscope comprising an objective according to  claim 5 . 
     
     
       47. A microlithographic projection exposure apparatus comprising a projection objective according to  claim 5 . 
     
     
       48. Use of a projection objective according to  claim 5  for microlithographic projection exposure. 
     
     
       49. A catadioptric objective comprising axial symmetry and at least a first partial objective,
 an intermediate image, and    a second partial objective,    one of said partial objectives being purely refractive and one being purely catoptric.    
     
     
       50. A microscope comprising an objective according to  claim 49 . 
     
     
       51. A microlithographic projection exposure apparatus comprising a projection objective according to  claim 49 . 
     
     
       52. Use of a projection objective according to  claim 49  for microlithographic projection exposure. 
     
     
       53. An objective comprising axial symmetry,
 an optical axis not being folded,  
 at least one curved mirror and  
 at least one lens and two intermediate images, and providing an image reduction.  
 
     
     
       54. An objective comprising axial symmetry,
 at least one curved mirror and  
 at least one lens and two intermediate images,  
 further comprising a partial objective with two opposing concave mirrors with central bores, and  
 with an optical axis, said concave mirrors being arranged axially symmetric with respect to said optical axis, their concave surfaces facing each other.  
 
     
     
       55. An objective comprising axial symmetry,
 at least one curved mirror and at least one lens and two intermediate images,  
 further comprising a partial objective with two opposing concave mirrors with central bores, and with an optical axis,  
 said concave mirrors being arranged axially symmetric with respect to said optical axis, their concave surfaces facing each other, wherein 
 a first refractive partial objective, a partial objective comprising at least one mirror, and a second refractive partial objective are arranged in sequence,  
 wherein the first refractive partial objective has a magnification ratio of −1/3 to −1/8.  
 
 
     
     
       56. An objective comprising axial symmetry,
 at least one curved mirror and at least one lens and two intermediate images,  
 further comprising a partial objective with two opposing concave mirrors with central bores, and  
 with an optical axis, said concave mirrors being arranged axially symmetric with respect to said optical axis, their concave surfaces facing each other,  
 wherein a first refractive partial objective, a partial objective comprising at least one mirror, and a second refractive partial objective are arranged in sequence,  
 wherein at least one of the first and second refractive partial objectives consists of a first positive lens group, a negative lens group and a second positive lens group.  
 
     
     
       57. An objective comprising axial symmetry,
 at least one curved mirror and  
 at least one lens and two intermediate images,  
 further comprising a partial objective with two opposing concave mirrors with central bores, and with an optical axis,  
 said concave mirrors being arranged axially symmetric with respect to said optical axis, their concave surfaces facing each other,  
 wherein a first refractive partial objective, a partial objective comprising at least one mirror, and a second refractive partial objective are arranged in sequence,  
 wherein said negative lens group comprises at least two negative menisci, their concave surfaces facing each other.  
 
     
     
       58. An objective comprising axial symmetry,
 at least one curved mirror and  
 at least one lens and two intermediate images,  
 wherein a first refractive partial objective, a partial objective comprising at least one mirror, and a second refractive partial objective are arranged in sequence,  
 wherein at least one aspherical lens surface is on a lens of a lens group with lesser lens diameters.  
 
     
     
       59. An objective comprising axial symmetry,
 at least one curved mirror and at least one lens and two intermediate images,  
 a first partial objective,  
 a first intermediate image,  
 a second partial objective,  
 a second intermediate image,  
 a third partial objective,  
 wherein the third partial objective has at least one positive concave air lens near its pupil plane, located at a distance from the second intermediate image of between 25% and 75% of the length of this partial objective.  
 
     
     
       60. An objective comprising axial symmetry,
 at least one curved mirror and  
 at least one lens and two intermediate images,  
 a first partial objective,  
 a first intermediate image,  
 a second partial objective,  
 a second intermediate image,  
 a third partial objective,  
 wherein an image side partial objective has two first lenses subsequent to the second intermediate image, which are menisci concave on the side of the intermediate image,  
 and two last lenses adjacent to the image, which are meniscus  menisci concave on the side of the image.  
 
     
     
       61. An objective comprising axial symmetry,
 at least one curved mirror and  
 at least one lens and two intermediate images,  
 a first partial objective,  
 a first intermediate image,  
 a second partial objective,  
 a second intermediate image,  
 a third partial objective,  
 wherein an image side partial objective has a pupil plane,  
 and at least one lens arranged at a distance from the image plane of between 25% and 75% of the length of the image side partial objective is a meniscus concave toward the pupil plane.  
 
     
     
       62. An objective comprising axial symmetry,
 at least one curved mirror and at least one lens and two intermediate images,  
 wherein at least one lens is arranged in a beam path between the  two concave mirrors.  
 
     
     
       63. An objective comprising axial symmetry,
 at least one curved mirror and  
 at least one lens and two intermediate images,  
 further comprising a partial objective with two opposing concave mirrors with central bores, and with an optical axis,  
 said concave mirrors being arranged axially symmetric with respect to said optical axis, their concave surfaces facing each other,  
 wherein each of said concave mirrors has a vertex situated on said optical axis, and  
 wherein each of said intermediate images has a maximum image height and is given on a surface with a piercing point on said optical axis,  
 and at least one of said vertici is spaced from at least one of said piercing points by a distance less than the maximum image height of the image having said piercing point.  
 
     
     
       64. An objective comprising axial symmetry,
 at least one curved mirror and  
 at least one lens and two intermediate images,  
 wherein the first  a refractive partial objective has a magnification ratio of −1/3 to −1/8.  
 
     
     
       65. An objective according to  claim 1 , wherein the image field is off- axis.   
     
     
       66. An objective according to  claim 1 , wherein said at least one curved mirror has an off- axis opening.   
     
     
       67. A microlithographic projection exposure objective comprising at least two concave mirrors with off axis openings, at least one intermediate image, and at least one purely refractive partial objective. 
     
     
       68. An objective comprising a purely catoptric partial objective, a purely refractive partial objective, an intermediate image between these partial objectives, said purely catoptric objective comprising mirrors with an off- axis opening.   
     
     
       69. An objective being a microlithographic reduction projection exposure objective comprising a catadioptric partial objective with two opposite concave mirrors and a magnification ratio in the range between − 1 / 0 . 7  and − 1 / 1 . 3 ; and a purely refractive partial objective comprising at least one lens with an aspheric surface, the objective being both side telecentric. 
     
     
       70. The objective of  claim 69 , comprising a second intermediate image and another partial objective. 
     
     
       71. The objective of  claim 69 , wherein said purely refractive partial objective has a magnification ratio of − 1 / 3  to − 1 / 8 . 
     
     
       72. The objective of  claim 69 , wherein said catoptric partial objective comprises at least one lens arranged in the beam path between the two concave mirrors. 
     
     
       73. The objective of  claim 69 , wherein the image field is off- axis.   
     
     
       74. The objective of  claim 69 , wherein said two opposite concave mirrors have off- axis openings.