Projection optical system and exposure apparatus with the same

Claim 2

A projection optical system according to claim 1, wherein said intermediate lens group in said second lens group has a negative refracting power.

Claim 3

A projection optical system according to claim 1, wherein said fifth lens group includes at least seven positive lenses.

Claim 4

A projection optical system according to claim 3, wherein said fifth lens group further includes at leans one negative lens.

Claim 5

A projection optical system according to claim 1, wherein said fifth lens group has a negative lens disposed as closest to said second object and shaped with a concave surface to said second object, and wherein said sixth lens group has a lens disposed as closest to said first object and shaped with a convex surface to said first object.

Claim 6

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

Claim 7

A projection optical system according to claim 1, wherein when f 1 is a focal length of said first lens group, f 2 is a focal length of said second lens group, f 3 is a focal length of said third lens group, f 4 is a focal length of said fourth lens group, f 5 is a focal length of said fifth lens group, f 6 is a focal length of said sixth lens group and L is a distance from said first object to said second object, said projection optical system satisfies the following conditions: f 1 /L<0.8 -0.10<f 2 /L 0.01<f 3 /L<1.0 f 4 /L<-0.005 0.01<f 5 /L<0.9 0.02<f 6 /L<1.6.

Claim 8

A projection optical system for projecting an image of a first object onto a second object, said projection optical system comprising: a first lens group with a positive refracting power provided between said first object and said second object; a second lens group with a negative refracting power provided between said first lens group and said second object, said second lens group including: a front lens with a negative refracting power disposed as closest to said first object and shaped with a concave surface to said second object; a rear lens with a negative refracting power disposed as closest to said second object and shaped with a concave surface to said first object; and an intermediate lens group provided between said front lens and said rear lens, said intermediate lens group comprising: a first intermediate lens with positive refracting power provided between said front lens and said rear lens, a second intermediate lens with a negative refracting power provided between said first intermediate lens and said rear lens, and a third intermediate lens with a negative refracting power provided between said second intermediate lens and said rear lens; a third lens group with a positive refracting power provided between said second lens group and said second object; a fourth lens group with a negative refracting power provided between said third lens group and said second object; a fifth lens group with a positive refracting power provided between said fourth lens group and said second object; and a sixth lens group with a positive refracting power provided between said fifth lens group and said second object; wherein, when f 1 is a focal length of said first lens group, f 2 is a focal length of said second lens group, f 3 is a focal length of said third lens group, f 4 is a focal length of said fourth lens group, f 5 is a focal length of said fifth lens group, f 6 is a focal length of said sixth lens group, L is a distance from said first object to said second object, r 2Ff is a radius of curvature of the surface of said front lens on the first object side, r 2Fr is a radius of curvature of the surface of said front lens on the second object side, r 2Rf is a radius of curvature of the surface of said rear lens on the first object side and r 2Rr is a radius of curvature of the surface of said rear lens on the second object side, said projection optical system satisfies the following conditions: f 1 /L<0.8 -0.10<f 2 /L 0.01<f 3 /L<1.0 f 4 /L<-0.005 0.01<f 5 /L<0.9 0.02<f 6 /L<1.6 1.00≤(r 2Ff -r 2Fr )/(r 2Ff +r 2Fr )<5.0 -10.0<(r 2Rf -r 2Rr )/(r 2Rf +r 2Rr )≤-1.00.

Claim 9

A projection optical system according to claim 8, wherein when I is an axial distance from said first object to a first-object-side focal point of said entire projection optical system and L is the distance from said first object to said second object, said projection optical system satisfies the following condition: 1.0<I/L.

Claim 10

A projection optical system according to claim 8, wherein said fifth lens group includes at least seven positive lenses.

Claim 11

A projection optical system according to claim 10, wherein said fifth lens group further includes at least one negative lens.

Claim 12

A projection optical system according to claim 8, wherein, when f 22 is a focal length of said second intermediate lens and f 23 is a focal length of said third intermediate lens, said projection optical system satisfies the following condition: 0.1<f 22 /f 23 <10.

Claim 13

A projection optical system according to claim 8, wherein said fifth lens group has a negative lens disposed closest to said second object with a concave surface of said negative lens facing said second object, and wherein said sixth lens group has a lens disposed as closest to said first object and shaped with a convex surface to said first object.

Claim 14

A projection optical system according to claim 13, wherein when r 5R is a radius of curvature of said negative lens in said fifth lens group on the second object side and r 6F is a radius of curvature of said lens in said sixth lens group on the first object side, said projection optical system satisfies the following condition: -0.90<(r 5R -r 6F )/(r 5R +r 6F )<-0.001.

Claim 15

A projection optical system according to claim 8, wherein when d 56 is an axial distance between said fifth lens group and said sixth lens group and L is the distance from said first object to said second object, said projection optical system satisfies the following condition: d 56 /L<0.017.

Claim 16

A projection optical system according to claim 8, wherein when r 6F is a radius of curvature of the lens surface included in said sixth lens group and disposed as closest to said first object, and d 6 is an axial distance from said lens surface of said sixth lens group to said second object, said projection optical system satisfies the following condition: 0.50<d 6 /r 6F <1.50.

Claim 17

A projection optical system according to claim 8, wherein said fifth lens group has a negative lens disposed as closest to said second object and shaped with a concave surface to said second object, and wherein when r 5F is a radius of curvature of said negative lens in said fifth lens group on the first object side and r 5R is a radius of curvature of said negative lens in said fifth lens group on the second object side, said projection optical system satisfies the following condition: 0.30<(r 5F -r 5R )/(r 5F +r 5R )<1.28.

Claim 18

A projection optical system according to claim 8, wherein when f 21 is a focal length of said first intermediate lens in said intermediate lens group and L is the distance from said first object to said second object, said projection optical system satisfies the following condition: 0.230<f 21 /L<0.40.

Claim 19

A projection optical system according to claim 8, wherein when f 2F is a focal length of said front lens in said second lens group and f 2R is a focal length of said rear lens in said second lens group, said projection optical system satisfies the following condition: 0≤f 2F /f 2R <18.

Claim 20

A projection optical system according to claim 8, wherein said intermediate lens group in said second lens group has a negative refracting power.

Claim 21

A projection optical system according to claim 8, wherein said first lens group has at least two positive lenses, said third lens group has at least three positive lenses, said fourth lens group has at least three negative lenses, and said sixth lens group has at least one positive lens.

Claim 22

A projection optical system according to claim 8, wherein said sixth lens group comprises three or less lenses each having at least one lens surface satisfying the following condition: 1/|ΦL|<20 where Φ : a refractive power of said lens surface, and L : the object-to-image distance from said first object to said second object.

Claim 23

A projection optical system according to claim 8, wherein said projection optical system has a magnification of 1/4.

Claim 24

An exposure apparatus, comprising: a first stage allowing a mask having a predetermined pattern to be held on a main surface thereof; a second stage allowing a photosensitive substrate to be held on a main surface thereof; an illumination optical system for emitting exposure light having a predetermined wavelength and transferring a predetermined pattern of said mask onto said substrate; and a projection optical system provided between said first stage and said second stage, said projection optical system comprising: a first lens group with a positive refracting power provided between said mask and said substrate; a second lens group with a negative refracting power provided between said first lens group and said substrate, said second lens group including: a front lens with a negative refracting power disposed as closest to said mask and shaped with a concave surface to said substrate, wherein when r 2Ff is a radius of curvature of the surface of said front lens on the mask side and r 2Fr is a radius of curvature of the surface of said front lens on the substrate side, said front lens has a shape defined by the following condition: 1.00≤(r 2Ff -r 2Fr )/(r 2Ff +r 2Fr )<5.0; a rear lens with a negative refracting power disposed as closest to said substrate and shaped with a concave surface to said mask, wherein when r 2Rf is a radius of curvature of the surface of said rear lens on the mask side and r 2Rr is a radius of curvature of the surface of said rear lens on the substrate side, said rear lens has a shape defined by the following condition: -10.0<(r 2Rf -r 2Rr )/(r 2Rf +r 2Rr )≤-1.00; and an intermediate lens group provided between said front lens and said rear lens, said intermediate lens group comprising: a first intermediate lens with positive refracting power provided between said front lens and said rear lens, a second intermediate lens with a negative refracting power provided between said first intermediate lens and said rear lens, and a third intermediate lens with a negative refracting power provided between said second intermediate lens and said rear lens; a third lens group with a positive refracting power provided between said second lens group and said substrate; a fourth lens group with a negative refracting power provided between said third lens group and said substrate; a fifth lens group with a positive refracting power provided between said fourth lens group and said substrate; and a sixth lens group with a positive refracting power provided between said fifth lens group and said substrate.

Claim 25

An exposure apparatus according to claim 24, wherein, in said projection optical system, said intermediate lens group in said second lens group has a negative refracting power.

Claim 26

An exposure apparatus according to claim 24, wherein, in said projection optical system, said fifth lens group includes at least seven positive lenses.

Claim 27

An exposure apparatus according to claim 26, wherein, in said projection optical system, said fifth lens group further includes at leans one negative lens.

Claim 28

An exposure apparatus according to claim 24, wherein, in said projection optical system, said fifth lens group has a negative lens disposed as closest to said substrate and shaped with a concave surface to said substrate, and wherein said sixth lens group has a lens disposed as closest to said mask and shaped with a convex surface to said mask.

Claim 29

An exposure apparatus according to claim 24, wherein, in said projection optical system, said first lens group has at least two positive lens, said third lens group has at least three positive lens, said fourth lens group has at least three negative lens and said sixth lens group has at least one positive lens.

Claim 30

An exposure apparatus according to claim 24, wherein, in said projection optical system, when f 1 is a focal length of said first lens group, f 2 is a focal length of said second lens group, f 3 is a focal length of said third lens group, f 4 is a focal length of said fourth lens group, f 5 is a focal length of said fifth lens group, f 6 is a focal length of said sixth lens group and L is a distance from said first object to said second object, said projection optical system satisfies the following conditions: f 1 /L<0.8 -0.10<f 2 /L 0.01<f 3 /L<1.0 f 4 /L<-0.005 0.01<f 5 /L<0.9 0.02<f 6 /L<1.6.