PROJECTION EXPOSURE APPARATUS FOR MICROLITHOGRAPHY
The invention relates to a projection exposure apparatus with a projection objective that serves to project a structure onto a substrate coated with a light-sensitive resist, wherein an immersion liquid is arranged between an optical element of the projection objective and the resist-coated substrate. As an immersion liquid saturated cyclic or polycyclic hydrocarbons can be used, such as for example cyclo-alkanes comprising up to 12 carbon atoms, saturated polycyclic hydrocarbons with 2 to 6 rings, bridged polycyclic hydrocarbons, cyclic ethers and derivatives of these substances.
1 - 28 . (canceled)
29 . Projection exposure apparatus with
a projection objective that projects a structure onto a substrate,
wherein an immersion liquid is arranged between a refractive optical element of the projection objective and the substrate,
wherein the immersion liquid is a saturated cyclic or polycyclic hydrocarbon.
30 . Projection exposure apparatus according to claim 29 , wherein the immersion liquid at an illumination wavelength of 248 nm has an extinction coefficient smaller than 1.19 cm −1 .
31 . Projection exposure apparatus according to claim 29 , wherein the immersion liquid at an illumination wavelength of 193 nm has an extinction coefficient smaller than 35.6 cm −1 .
32 . Projection exposure apparatus according to claim 29 , wherein the distance between the optical element and the coated substrate is adjusted so that the transmission through the immersion liquid is more than 70%.
33 . Projection exposure apparatus according to claim 29 , wherein the projection exposure apparatus comprises a regeneration circuit for the immersion liquid.
34 . Projection exposure apparatus according to claim 33 , wherein the regeneration circuit comprises a distillation apparatus.
35 . Projection exposure apparatus according to claim 29 , wherein the immersion liquid is a cyclo-alkane or a cyclo-alkane derivative.
36 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid is cyclohexane.
37 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid is a cyclohexane derivative with the molecular formula C 6 R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 R 11 R 12 , wherein R 1 to R 12 are selected, respectively, from the group that consists of —H and —C n H 2n+1 , wherein n represents a positive integer between 1 and 12.
38 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid is cyclooctane.
39 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid is a cyclooctane derivative with the molecular formula C 8 R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 R 11 R 12 R 13 R 14 R 15 R 16 , wherein R 1 to R 16 are selected, respectively, from the group that consists of —H and —C n H 2n+1 , where n represents a positive integer between 1 and 12.
40 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid has the molecular formula C k H 2k , where k represents a positive integer between 7 and 12.
41 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid is selected from the group that consists of cyclopentane, cycloheptane, cyclononane, cyclodecane, cycloundecane and cyclododecane.
42 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid is a derivative of a cycloalkane with the molecular formula C k R 1 . . . R 2k , wherein R 1 to R 2k are selected, respectively, from the group that consists of —H and C n H 2n+1 , wherein k is a positive integer between 7 and 12 and n is a positive integer between 1 and 12.
43 . Projection exposure apparatus according to claim 42 , wherein n is a positive integer between 1 and 5.
44 . Projection exposure apparatus according to claim 35 , wherein the immersion liquid is a derivative of a cyclo-alkane selected from the group consisting of cyclopentane, cycloheptane, cyclononane, cyclodecane, cycloundecane or cyclododecane, comprising a side chain R, wherein R is selected from the group that consists of —H and —C n H 2n+1 .
45 . Projection exposure apparatus according to claim 29 , wherein the immersion liquid is selected from the group that consists of decahydronaphthalene, perhydrofluorene, perhydroindene, perhydrophenanthrene, perhydrobenzopyrene, perhydroanthrazene, perhydrofluorantene, perhydroindenopyrene, perhydrobenzofluoranthene, perhydrochrysene, perhydrotetraphenylene, perhydropentalene, perhydroazulene, perhydroheptalene, perhydrobiphenylene, perhydroindazene, perhydroacenaphthylene, perhydrophenalene, perhydropyrene, perhydronaphthazene, and perhydrocoronene.
46 . Projection exposure apparatus according to claim 29 , wherein the immersion liquid is a derivative of one of the substances selected from the group that consists of decahydronaphthalene, perhydrofluorene, perhydroindene, perhydrophenanthrene, perhydrobenzopyrene, perhydroanthrazene, perhydrofluoranthene, perhydroindenopyrene, perhydrobenzofluoranthene, perhydrochrysene, perhydrotetraphenylene, perhydropentalene, perhydroazulene, perhydroheptalene, perhydrobiphenylene, perhydroindazene, perhydroacenaphthylene, perhydrophenalene, perhydropyrene, perhydronaphthazene, and perhydrocoronene, comprising a side chain R, wherein R is selected from the group that consists of —H and —C n H 2n+1 .
47 . Projection exposure apparatus according to claim 29 , wherein the immersion liquid is a bridged polycyclic hydrocarbon.
48 . Projection exposure apparatus according to claim 47 wherein the immersion liquid is selected from the group that consists of norbornane, adamantane, tricyclodecane, or bicyclo [3.3.2]-decane.
49 - 86 . (canceled)