Projection objective having adjacently mounted aspheric lens surfaces

1. A projection exposure system defining an optical axis and comprising:

an illuminating unit mounted on said optical axis for transmitting a light beam along said optical axis;

a projection objective arranged on said optical axis downstream of said illuminating unit;

a mask held in the beam path of said light beam between said illuminating unit and said projection objective;

a substrate holder for holding a substrate in said beam path downstream of said projection objective; and,

said projection objective defining a maximum lens diameter and including:

a plurality of lenses defining an object plane and an image plane;

at least two of said lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere;

said double asphere being mounted at a distance from said image plane corresponding at least to said maximum lens diameter;

the lenses of said double asphere defining a mean lens diameter; and,

said mutually adjacent lens surfaces being mounted at a spacing from each other which is less than half of said mean lens diameter.

2. A method of making a microstructured component utilizing a projection exposure system including an illuminating unit mounted on said optical axis for transmitting a light beam along said optical axis; a projection objective arranged on said optical axis downstream of said illuminating unit; a mask held in the beam path of said light beam between said illuminating unit and said projection objective and said mask holding a pattern; a substrate holder for holding a substrate in said beam path downstream of said projection objective; and, said projection objective defining a maximum lens diameter and including: a plurality of lenses defining an object plane and an image plane; at least two of said lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere; said double asphere being mounted at a distance from said image plane corresponding at least to said maximum lens diameter; the lenses of said double asphere defining a mean lens diameter; and, said mutually adjacent lens surfaces being mounted at a spacing from each other which is less than half of said mean lens diameter, the method comprising the steps of:

providing said substrate as a substrate having a light-sensitive layer thereon;

holding said substrate in said beam path exposing said light-sensitive layer with ultraviolet laser light from said illuminating unit; and,

developing the exposed light-sensitive layer to structure said substrate to have said pattern of said mask.

3. A refractive projection objective comprising:

two lens groups of negative refractive power;

at least one of said lens groups of negative refractive power including only two lenses of negative refractive power;

the other one of said lens groups of negative refractive power having maximally two lenses of negative refractive power; and,

said lens groups defining at least two constrictions and an aspheric lens surface is arranged in the second constriction.

4. The refractive projection objective of claim 3 , further comprising a lens group of positive refractive power including at least one lens having an aspheric surface; and, a diaphragm mounted in said lens group of positive refractive power.

5. The refractive projection objective of claim 3 , further comprising at least two lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere.

6. The refractive projection objective of claim 3 , wherein said refractive projection objective defines a maximum lens diameter and said refractive projection objective further comprises:

a plurality of lenses defining an object plane and an image plane;

at least two of said lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere;

said double asphere being mounted at a distance from said image plane corresponding at least to said maximum lens diameter;

the lenses of said double asphere defining a mean lens diameter; and,

said mutually adjacent lens surfaces being mounted at a spacing from each other which is less than half of said mean lens diameter.

7. The projection objective of claim 6 , wherein said plurality of lenses defines at least two constrictions.

8. The projection objective of claim 6 , comprising at least two of said double aspheres and said spacings thereof being equidistant.

9. The projection objective of claim 6 , wherein the radii of the best-fitting spherical lens surfaces of one of said double aspheres differ from one another by less than 30%.

10. The projection objective of claim 6 , wherein the apex radii of the best-fitting spherical lens surfaces of a double asphere, which are assigned to the respective aspheric lens surfaces, differ from one another by less than 30%.

11. The projection objective of claim 6 , wherein the diameters of the first thirteen lens surfaces hardly differ from each other, preferably by less than 10%.

12. The projection objective of claim 6 , wherein a numerical aperture of at least 0.8 is made available by the double asphere.

13. The projection objective of claim 6 , wherein a numerical aperture of at least 0.9 is made available by the double asphere.

14. The projection objective of claim 6 , wherein two mutually adjacent lens surfaces define an intermediate space chargeable with a fluid.

15. The projection objective of claim 6 , wherein at least 40% of the lenses are spherical.

16. The projection objective of claim 6 , wherein at least 60% of the lenses are spherical.

17. A projection objective defining a maximum lens diameter and including:

a plurality of lenses defining an object plane and an image plane;

at least two of said lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere;

said double asphere being mounted at a distance from said image plane corresponding at least to said maximum lens diameter;

the lenses of said double asphere defining a mean lens diameter;

said mutually adjacent lens surfaces being mounted at a spacing from each other which is less than half of said mean lens diameter; and,

said projection objective being a refractive projection objective defining a maximum lens diameter and including:

at least five lens groups having lenses defining lens surfaces and defining an object plane and an image plane;

at least two of said lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere; and,

said double asphere being mounted from said image plane at a distance of at least said maximum lens diameter.

18. The refractive projection objective of claim 17 , wherein said plurality of lenses defines at least two constrictions.

19. The refractive projection objective of claim 17 , wherein the aspheric surfaces are arranged on different lenses.

20. The refractive projection objective of claim 18 , wherein all aspheric lenses are mounted ahead of the first constriction.

21. The refractive projection objective of claim 17 , comprising two of said double aspheres and the mutually adjacent lens surfaces of each double asphere are mounted at a spacing from each other of at most their mean half lens diameter measured from the optical axis.

22. The refractive projection objective of claim 21 , wherein the mutually adjacent aspheric lens surfaces of each of said aspheres defines an air gap measured on the optical axis of a maximum of 20% of the mean radius of the corresponding asphere.

23. The refractive projection objective of claim 17 , wherein a numerical aperture of at least 0.8 is made available by the double asphere.

24. The refractive projection objective of claim 17 , wherein a numerical aperture of at least 0.9 is made available by the double asphere.

25. The refractive projection objective of claim 17 , wherein two mutually adjacent lens surfaces define an intermediate space chargeable with a fluid.

26. The refractive projection objective of claim 17 , wherein at least 40% of the lenses are spherical.

27. The refractive projection objective of claim 17 , wherein at least 60% of the lenses are spherical.

28. A projection objective defining a maximum lens diameter and including:

a plurality of lenses defining an object plane and an image plane;

at least two of said lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere;

said double asphere being mounted at a distance from said image plane corresponding at least to said maximum lens diameter;

the lenses of said double asphere defining a mean lens diameter;

said mutually adjacent lens surfaces being mounted at a spacing from each other which is less than half of said mean lens diameter; and,

said projection objective being a refractive projection objective including:

two lens groups of negative refractive power; and,

at least one of said lens groups of negative refractive power including only two lenses of negative refractive power.

29. The refractive projection objective of claim 28 , wherein the other one of said lens groups of negative refractive power has maximally two lenses of negative refractive power.

30. The refractive projection objective of claim 29 , wherein said lens groups define at least two constrictions and an aspheric lens surface is arranged in the second constriction.

31. The refractive projection objective of claim 29 , further comprising a lens group of positive refractive power including at least one lens having an aspheric surface; and, a diaphragm mounted in said lens group of positive refractive power.

32. The refractive projection objective of claim 28 , further comprising at least two lenses having respective mutually adjacent lens surfaces which are aspheric to define a double asphere.