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US 5,852,490 AGranted
Projection exposure method and apparatus
AssigneeNikon Corporation
InventorTomoyuki Matsuyama
Life of this patent
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Abstract
A projection exposure system, which is used to transfer a pattern from a reticle or mask onto a substrate, incorporates a projection optical system that is capable of maintaining the same performance as that which can be found in an ideal environment, even when the actual use environment (e.g. atmospheric pressure and temperature) is not ideal. In addition, the projection optical system is able to recover the same performance as in an ideal environment through relatively minor adjustment of its projection optical system even when atmospheric pressure significantly changes due to, e.g., a change in location and altitude where the system is used.
Claims12
A projection exposure apparatus for transferring a pattern formed on a reticle onto substrate, comprising:
- an illumination optical system to uniformly illuminate said reticle with a wavelength .lambda.;
- a first supporting member to support said reticle;
- a second supporting member to support said substrate and;
- a projection optical system disposed between said reticle and said substrate, said projection optical system projecting a ray bundle having a numerical aperture of at least 0.55, wherein said projection optical system projects said pattern on said reticle illuminated by said illumination optical system onto said substrate with said ray bundle while satisfying the following conditions:
- .vertline.dSAp.vertline.<0.3.times..lambda./(NA).sup.2
- .vertline.dCOMAp.vertline.<0.3.times..lambda./(NA),
- where, dSAp is an amount of change in spherical aberration of a maximum numerical aperture of said projection optical system when atmospheric pressure surrounding said projection optical system changes by 30 mmHg, dCOMAp is an amount of change in coma aberration of the maximum numerical aperture at a maximum image height of said projection optical system when atmospheric pressure surrounding said projection optical system changes by 30 mmHg, and NA is a maximum numerical aperture of said projection optical system.
4 more elements
A projection exposure apparatus for transferring a pattern formed on a reticle onto a substrate, comprising:
- an illumination optical system to uniformly illuminate said reticle with a wavelength .lambda.;
- a first supporting member which supports said reticle;
- a second supporting member which supports said substrate;
- a projection optical system disposed between said reticle and said substrate, said projection optical system projecting a ray bundle having a numerical aperture of at least 0.55, wherein said projection optical system projects said pattern on said reticle illuminated by said illumination optical system onto said substrate with said ray bundle while satisfying the following conditions:
- .vertline.dSAt.vertline.<0.3.times..lambda./(NA).sup.2
- .vertline.dCOMAt.vertline.<0.3.times..lambda./(NA)
- .vertline.dMt.vertline.<0.2.times..lambda./(NA).sup.2
- .vertline.dYt.vertline.<0.05.times..lambda./(NA),
- wherein,
- dSAt is an amount of change in spherical aberration of a maximum numerical aperture of said projection optical system when a surrounding temperature of said projection optical system changes by 3.degree. C.;
- dCOMAt is an amount of change in coma aberration of the maximum numerical aperture at a maximum image height of said projection optical system when the surrounding temperature of said projection optical system changes by 3.degree. C.;
- dMt is an amount of change in field curvature at the maximum image height of said projection optical system when the surrounding temperature of said projection optical system changes by 3.degree. C.;
- dYt is an amount of change in image height at the maximum image height of said projection optical system when the surrounding temperature of said projection optical system changes by 3.degree. C. and
- NA is the maximum numerical aperture of said projection optical system.
11 more elements
A semiconductor manufacturing method for transferring a pattern formed on a reticle onto a photosensitive substrate, comprising the steps of:
- illuminating said pattern on said reticle with a source of illumination having a wavelength .lambda. such that at least a portion of said illumination passes through said pattern formed on said reticle;
- guiding said illumination which has passed through said reticle to a projection optical system which satisfies the following conditions:
- .vertline.dSAp.vertline.<0.3.times..lambda./(NA).sup.2
- .vertline.dCOMAp.vertline.<0.3.times..lambda./(NA);
- and
- exposing said photosensitive substrate with said guided illumination, wherein said guided illumination comprises a projecting ray bundle with a numerical aperture of at least 0.55, and where
- dSAp is an amount of change in spherical aberration of a maximum numerical aperture ray of said projection optical system when atmospheric pressure surrounding said projection optical system changes by 30 mmHg,
- dCOMAp is an amount of change in coma aberration of the maximum numerical aperture ray at a maximum image height of said projection optical system when the atmospheric pressure surrounding said projection optical system changes by 30 mmHg, and
- NA is the maximum numerical aperture of said projection optical system.
6 more elements
A semiconductor manufacturing method for transferring a pattern formed on a reticle onto a photosensitive substrate, said method comprising the steps of:
- illuminating said pattern on said reticle with a source of illumination having a wavelength .lambda. such that at least a portion of said illumination passes through said pattern formed on said reticle;
- guiding said portion of said illumination to a projection optical system which satisfies each of the following conditions:
- .vertline.dSAt.vertline.<0.3.times..lambda./(NA).sup.2
- .vertline.dCOMAt.vertline.<0.3.times..lambda./(NA)
- .vertline.dMt.vertline.<0.2.times..lambda./(NA).sup.2
- .vertline.dYt.vertline.<0.05.times..lambda./(NA).sup.2
- exposing said photosensitive substrate with said guided illumination, wherein said guided illumination comprises a projecting ray bundle with a numerical aperture of at least 0.55, and where
- dSAt is an amount of change in spherical aberration of a maximum numerical aperture ray of said projection optical system when a temperature surrounding said projection optical system changes by 3.degree. C.,
- dCOMAt is an amount of change in coma aberration of the maximum numerical aperture ray at a maximum image height of said projection optical system when the temperature surrounding said projection optical system changes by 3.degree. C.,
- dMt is an amount of change in field curvature at the maximum image height of said projection optical system when the temperature surrounding said projection optical system changes by 3.degree. C.,
- dYt is an amount of change in image height at the maximum image height of said projection optical system when the temperature surrounding said projection optical system changes by 3.degree. C.,
- and NA is the maximum numerical aperture of said projection optical system.
9 more elements
Dependencies are inferred from the claim text.