Exposure apparatus

Claim 2

A projection optical system according to claim 1, wherein said first lens group includes at least two positive lenses, said third lens group includes at least three positive lenses, said fourth lens group includes at least three negative lenses, said fifth lens group includes at least five positive lenses and at least one negative lens, and said sixth lens group includes at least one positive lens.

Claim 3

A projection optical system according to claim 1, wherein said second lens group comprises a front lens placed as closest to the first object and having negative refracting power with a concave surface to the second object, a rear lens placed as closest to the second object and having negative refracting power with a concave surface to the first object, and an intermediate lens group placed between said front and rear lenses in said second lens group, and wherein said intermediate lens group has a first lens with positive refracting power, a second lens with negative refracting power, a third lens with negative refracting power, and a fourth lens with negative refracting power in the named order from the side of the first object.

Claim 4

A projection optical system according to claim 3, wherein the first lens with positive refracting power in said intermediate lens group in said second lens group has a lens shape with a convex surface to the second object.

Claim 5

A projection optical system according to claim 2, wherein said fourth lens group comprises a front lens placed as closest to the first object and having negative refracting power with a concave surface to the second object, a rear lens placed as closest to the second object and having negative refracting power with a concave surface to the first object, and at least one negative lens placed between said front lens in said fourth lens group and said rear lens in said fourth lens group.

Claim 6

A projection optical system according to claim 1, wherein said fifth lens group comprises a negative meniscus lens, and a positive lens placed as adjacent to a concave surface of said negative meniscus lens and having a convex surface opposed to the concave surface of said negative meniscus lens.

Claim 7

A projection optical system according to claim 6, wherein said negative meniscus lens and said positive lens adjacent to the concave surface of said negative meniscus lens are placed between at least one positive lens in said fifth lens group and at least one positive lens in said fifth lens group.

Claim 8

A projection optical system according to claim 1, wherein said fifth lens group comprises a negative lens placed as closest to the second object and having a concave surface opposed to the second object.

Claim 9

A projection optical system according to claim 8, wherein said sixth lens group comprises a lens placed as closest to the first object and having a convex surface opposed to the first object.

Claim 10

A projection optical system located between a first and second object, for projecting an image of the first object onto the second object, said projection optical system having a first lens group with positive refracting power, a second lens group, a third lens group with positive refracting power, a fourth lens group with negative refracting power, a fifth lens group with positive refracting power, and a sixth lens group with positive refracting power in the named order from the side of the first object, wherein said second lens group comprises a front lens placed as closest to the first object and having negative refracting power with a concave surface to the second object, a rear lens placed as closest to the second object and having negative refracting power with a concave surface to the first object, and an intermediate lens group placed between said front and rear lenses in said second lens group, wherein said intermediate lens group has a first lens with positive refracting power, a second lens with negative refracting power, a third lens with negative refracting power, and a fourth lens with negative refracting power in the named order from the side of the first object, and wherein the following conditions are satisfied when a focal length of said first lens group is f₁, a focal length of said second lens group is f₂, a focal length of said third lens group is f₃, a focal length of said fourth lens group is f₄, a focal length of said fifth lens group is f₅, a focal length of said sixth lens group is f₆, an overall focal length of said second lens to said fourth lens in said intermediate lens group in said second lens group is f n , and a distance from the first object to the second object is L: 0.1 < f 1 /f 3 < 17 0.1 < f 2 /f 4 < 14 0.01 < f 5 /L < 0.9 0.02 < f 6 /L < 1.6 0.01 < f n /f 2 < 2.0.

Claim 11

A projection optical system according to claim 10, wherein the following condition is satisfied when an axial distance from the first object to a first-object-side focal point of the whole of said projection optical system is I and the distance from the first object to the second object is L: 1.0 < I/L.

Claim 12

A projection optical system according to claim 10, wherein said first lens group includes at least two positive lenses, said third lens group includes at least three positive lenses, said fourth lens group includes at least three negative lenses, said fifth lens group includes at least five positive lenses and at least one negative lens, and said sixth lens group includes at least one positive lens.

Claim 13

A projection optical system according to claims 10, wherein said intermediate lens group in said second lens group has negative refracting power.

Claim 14

A projection optical system according to claims 10, wherein the following condition is satisfied when the focal length of said second lens group is f₂ and the distance from the first object to the second object is L: -0.8 < f 2 /L < -0.050.

Claim 15

A projection optical system according to claims 10, wherein the following condition is satisfied when a focal length of said front lens placed as closest to the first object in said second lens group and having negative refracting power with a concave surface to the second object is f 2F and a focal length of said rear lens placed as closest to the second object in said second lens group and having negative refracting power with a concave surface to the first object is f 2R : 0 ≦ f 2F /f 2R < 18.

Claim 16

A projection optical system according to claim 10, wherein the following condition is satisfied when a focal length of said third lens with negative refracting power in said second lens group is f₂₃ and a focal length of said fourth lens with negative refracting power in said intermediate lens group in said second lens group is f₂₄: 0.07 < f 24 /f 23 < 7.

Claim 17

A projection optical system according to claim 10, wherein the following condition is satisfied when a focal length of said second lens with negative refracting power in said intermediate lens group in said second lens group is f₂₂ and a focal length of said third lens with negative refracting power in said intermediate lens group in said second lens group is f₂₃: 0.1 < f 22 /f 23 < 10.

Claim 18

A projection optical system according to claim 10, wherein the following condition is satisfied when an axial distance from a second-object-side lens surface of said fourth lens with negative refracting power in said intermediate lens group in said second lens group to a first-object-side lens surface of said rear lens in said second lens group is D and the distance from the first object to the second object is L: 0.05 < D/L < 0.4.

Claim 19

A projection optical system according to claim 10, wherein said first lens with positive refracting power in said intermediate lens group in said second lens group has a lens shape with a convex surface to the second object, and wherein the following condition is satisfied when the refracting power of a second-object-side lens surface of said first lens with positive refracting power in said intermediate lens group in said second lens group is Φ₂₁ and the distance from the first object to the second object is L: 0.54 < 1/(Φ 21 ·L) < 10.

Claim 20

A projection optical system according to claim 10, wherein the following condition is satisfied when a focal length of said first lens with positive refracting power in said intermediate lens group in said second lens group is f₂₁ and the distance from the first object to the second object is L: 0.230 < f 21 /L < 0.40.

Claim 21

A projection optical system according to claim 10, wherein the following condition is satisfied when the focal length of said fourth lens group is f₄ and the distance from said the first object to the second object is L: -0.098 < f 4 /L < -0.005.

Claim 22

A projection optical system according to claim 10, wherein said fourth lens group comprises a front lens placed as closest to the first object and having negative refracting power with a concave surface to the second object, a rear lens placed as closest to the second object and having negative refracting power with a concave surface to the first object, and at least one negative lens placed between said front lens in said fourth lens group and said rear lens in said fourth lens group, and wherein the following condition is satisfied when a radius of curvature on the first object side in said rear lens placed as closest to the second object in said fourth lens group is r 4F and a radius of curvature on the second object side in said rear lens placed as closest to the second object in said fourth lens group is r 4R : -1.00 ≦ (r 4F - r 4R )/(r 4F + r 4R ) < 0.

Claim 23

A projection optical system according to claim 10, wherein said fifth lens group comprises a negative meniscus lens, and a positive lens placed as adjacent to a concave surface of said negative meniscus lens and having a convex surface opposed to the concave surface of said negative meniscus lens, and wherein the following condition is satisfied when a radius of curvature of the concave surface of said negative meniscus lens in said fifth lens group is r 5n and a radius of curvature of the convex surface opposed to the concave surface of said negative meniscus lens in said positive lens placed adjacent to the concave surface of said negative meniscus lens in said fifth lens group is r 5p : 0 < (r 5p - r 5n )/(r 5p + r 5n ) < 1.

Claim 24

A projection optical system according to claim 23, wherein said negative meniscus lens and said positive lens adjacent to the concave surface of said negative meniscus lens are placed between at least one positive lens in said fifth lens group and at least one positive lens in said fifth lens group.

Claim 25

A projection optical system according to claim 10, wherein said fifth lens group comprises a negative lens placed as closest to the second object and having a concave surface opposed to the second object, and wherein the following condition is satisfied when a radius of curvature on the first object side in said negative lens closest to the second object in said fifth lens group is r 5F and a radius of curvature on the second object side in said negative lens closest to the second object in said fifth lens group is r 5R : 0.30 < (r 5F - r 5R )/(r 5F + r 5R ) < 1.28.

Claim 26

A projection optical system according to claim 10, wherein said fifth lens group comprises a negative lens placed as closest to the second object and having a concave surface opposed to the second object and said sixth lens group comprises a lens placed as closest to the first object and having a convex surface opposed to the first object, and wherein the following condition is satisfied when a radius of curvature on the second object side, of said negative lens placed as closest to the second object in said fifth lens group is r 5R and a radius of curvature on the first object side, of said lens placed as closest to the first object in said sixth lens group is r 6F : -0.90 < (r 5R - r 6F )/(r 5R + r 6F ) < -0.001.

Claim 27

A projection optical system according to claim 10, wherein the following condition is satisfied when a lens group separation between said fifth lens group and said sixth lens group is d₅₆ and the distance from the first object to the second object is L: d 56 /L < 0.017.

Claim 28

A projection optical system according to claim 10, wherein the following condition is satisfied when a radius of curvature of a lens surface closest to the first object in said sixth lens group is r 6F and an axial distance from the lens surface closest to the first object in said sixth lens group to the second object is d₆: 0.50 < d 6 /r 6F < 1.50.

Claim 29

A projection optical system according to claim 10, wherein said sixth lens group comprises three or less lenses having at least one surface satisfying the following condition: 1/|ΦL| < 20. where Φ: refracting power of the lens surface; L: object-image distance from the first object to the second object.

Claim 30

A projection optical system according to claims 10, wherein a magnification of said projection optical system is 5:1.

Claim 31

An exposure apparatus comprising: a stage allowing a photosensitive substrate to be held on a main surface thereof; an illumination optical system for emitting exposure light of a predetermined wavelength and transferring a predetermined pattern on a mask onto the substrate; and a projecting optical system for projecting an image of the mask, on the substrate surface, said projecting optical system having: a first lens group with positive refracting power, said first lens group being placed betwen the mask and the main surface of said stage; a second lens group with negative refracting power, said second lens group being placed between said first lens group and the main surface of said stage; a third lens group with positive refracting power, said third lens group being placed between said second lens group and the main surface of said stage; a fourth lens group with negative refracting power, said fourth lens group being placed between said third lens group and the main surface of said stage; a fifth lens group with positive refracting power, said fifth lens group being placed between said fourth lens group and the main surface of said stage; and a sixth lens group with positive refracting power, said sixth lens group being placed between said fifth lens group and the main surface of said stage.

Claim 32

An exposure apparatus according to claim 31, wherein said second lens group comprises a front lens placed as closest to the first object and having negative refracting power with a concave surface to the second object, a rear lens placed as closest to the second object and having negative refracting power with a concave surface to the first object, and an intermediate lens group placed between said front and rear lenses in said second lens group, wherein said intermediate lens group has a first lens with positive refracting power, a second lens with negative refracting power, a third lens with negative refracting power, and a fourth lens with negative refracting power in the named order from the side of the first object, and wherein the following conditions are satisfied when a focal length of said first lens group is f₁, a focal length of said second lens group is f₂, a focal length of said third lens group is f₃, a focal length of said fourth lens group is f₄, a focal length of said fifth lens group is f₅, a focal length of said sixth lens group is f₆, an overall focal length of said second lens to said fourth lens in said intermediate lens group in said second lens group is f n , and a distance from the first object to the second object is L: 0.1 < f 1 /f 3 < 17 0.1 < f 2 /f 4 < 14 0.01 < f 5 /L < 0.9 0.02 < f 6 /L < 1.6 0.01 < f n /f 2 < 2.0.