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Illumination device with allowable error amount of telecentricity on the surface of the object to be illuminated and exposure apparatus using the same

Assignee: Nikon Corp
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Filing: 1995-03-10
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Granted: 1997-01-14
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Expires: 2015-03-10
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Abstract

Abstract The illumination device of the present invention is directed to an illumination device comprising a light source system for generating illumination light, a collimate optical system for collimating the illumination light from the light source system into a substantially collimated light beam, an optical integrator for forming a plurality of light source images on the basis of the light beam from the collimate optical system, a variable aperture stop arranged at an exit surface of the optical integrator, and a condenser lens system for guiding the light beam from the optical integrator to a surface of an object to be illuminated, and making an incident surface of the optical integrator conjugate with the surface of the object to be illuminated.

Inventors

  • 👤 Hideki Komatsuda
  • 👤 Hideo Hirose
  • 👤 Tetsuo Kikuchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 08:42
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G03F7/70075; G03F7/70091

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 237 words
An illumination device which comprises: a light source system for generating illumination light; an optical integrator which is constituted by lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system; a variable aperture stop arranged on a position where said plurality of light source images are formed; and a condenser optical system for guiding the light beams from said optical integrator to a surface of an object to be illuminated, wherein when a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator is represented by 2d, a focal length of said condenser optical system is represented by f con , maximum and minimum values of an effective diameter of said variable aperture stop are respectively represented by 2R max and 2R min , and average values of irradiance on the surface of the object to be illuminated respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values are represented by E max and E min , and an allowable error amount of telecentricity on the surface of the object to be illuminated is represented by A, said illumination device satisfies: d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}≦f.sub.con ·A wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.
Claim 2
Dependent Claim 237 words
An illumination device which comprises: a light source system for generating illumination light; an optical integrator which is constituted by lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system; a variable aperture stop arranged on a position where said plurality of light source images are formed; and a condenser optical system for guiding the light beams from said optical integrator to a surface of an object to be illuminated, wherein when a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator is represented by 2d, a focal length of said condenser optical system is represented by f con , maximum and minimum values of an effective diameter of said variable aperture stop are respectively represented by 2R max and 2R min , and average values of irradiance on the surface of the object to be illuminated respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values are represented by E max and E min , and an allowable error amount of telecentricity on the surface of the object to be illuminated is represented by A, said illumination device satisfies: d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}≦f.sub.con ·A wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.
Claim 3
Dependent Claim 28 words
A device according to claim 1, further comprising a collimate optical system for converting the illumination light from said light source system into a substantially collimated light beam.
Claim 4
Dependent Claim 29 words
A device according to claim 1, wherein said condenser optical system makes an incident surface of said optical integrator conjugate with the surface of the object to be illuminated.
Claim 5
Dependent Claim 36 words
A device according to claim 1, wherein said light source system comprises a light source for generating the illumination light, and an elliptic mirror having a first focal point at which said light source is arranged.
Claim 6
Dependent Claim 26 words
A device according to claim 1, wherein the allowable error amount A of telecentricity on the surface of the object to be illuminated is 0.006 rad.
Claim 7
Dependent Claim 26 words
A device according to claim 1, wherein the allowable error amount A of telecentricity on the surface of the object to be illuminated is 0.004 rad.
Claim 8
Dependent Claim 26 words
A device according to claim 1, wherein the allowable error amount A of telecentricity on the surface of the object to be illuminated is 0.002 rad.
Claim 9
Dependent Claim 252 words
An exposure apparatus which comprises: a light source system for generating illumination light; a optical integrator which is constituted by lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system; a variable aperture stop arranged on a position where said plurality of light source images are formed; a condenser optical system for guiding the light beams from said optical integrator to a mask surface; and a projection optical system for exposing a pattern on the mask surface onto an object to be exposed, wherein when a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator is represented by 2d, a focal length of said condenser optical system is represented by f con , a projection magnification of said projection optical system is represented by B, maximum and minimum values of an effective diameter of said variable aperture stop are respectively represented by 2R max and 2R min , and average values of irradiance on the mask surface respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values are represented by E max and E min , and an allowable error amount of telecentricity on the mask surface is represented by a, said exposure apparatus satisfies: d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}≦f.sub.con ·B·a wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.
Claim 10
Dependent Claim 252 words
An exposure apparatus which comprises: a light source system for generating illumination light; a optical integrator which is constituted by lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system; a variable aperture stop arranged on a position where said plurality of light source images are formed; a condenser optical system for guiding the light beams from said optical integrator to a mask surface; and a projection optical system for exposing a pattern on the mask surface onto an object to be exposed, wherein when a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator is represented by 2d, a focal length of said condenser optical system is represented by f con , a projection magnification of said projection optical system is represented by B, maximum and minimum values of an effective diameter of said variable aperture stop are respectively represented by 2R max and 2R min , and average values of irradiance on the mask surface respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values are represented by E max and E min , and an allowable error amount of telecentricity on the mask surface is represented by a, said exposure apparatus satisfies: d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}≦f.sub.con ·B·a wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.
Claim 11
Dependent Claim 28 words
A apparatus according to claim 8, further comprising a collimate optical system for converting the illumination light from said light source system into a substantially collimated light beam.
Claim 12
Dependent Claim 24 words
A apparatus according to claim 8, wherein said condenser optical system makes an incident surface of said optical integrator conjugate with the mask surface.
Claim 13
Dependent Claim 36 words
An apparatus according to claim 8, wherein said light source system comprises a light source for generating the illumination light, and an elliptic mirror having a first focal point at which said light source is arranged.
Claim 14
Dependent Claim 26 words
An apparatus according to claim 8, wherein the allowable error amount a of telecentricity on the surface of said object to be exposed is 0.03 rad.
Claim 15
Dependent Claim 26 words
An apparatus according to claim 8, wherein the allowable error amount a of telecentricity on the surface of said object to be exposed is 0.02 rad.
Claim 16
Dependent Claim 26 words
An apparatus according to claim 8, wherein the allowable error amount a of telecentricity on the surface of said object to be exposed is 0.01 rad.
Claim 17
Dependent Claim 208 words
An illumination device which comprises: a light source system for generating illumination light; an optical integrator comprised of lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system, a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator being represented by 2d; a variable aperture stop arranged on a position where said plurality of light source images are formed, maximum and minimum values of an effective diameter of said variable aperture stop being respectively represented by 2R max and 2R min , and average values of irradiance on the surface of the object to be illuminated respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values being represented by E max and E min , and a condenser optical system for guiding the light beams from said optical integrator to a surface of an object to be illuminated, a focal length of said condenser optical system represented by f con satisfying: f.sub.con ≧d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}/0.006 wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.
Claim 18
Dependent Claim 208 words
An illumination device which comprises: a light source system for generating illumination light; an optical integrator comprised of lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system, a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator being represented by 2d; a variable aperture stop arranged on a position where said plurality of light source images are formed, maximum and minimum values of an effective diameter of said variable aperture stop being respectively represented by 2R max and 2R min , and average values of irradiance on the surface of the object to be illuminated respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values being represented by E max and E min , and a condenser optical system for guiding the light beams from said optical integrator to a surface of an object to be illuminated, a focal length of said condenser optical system represented by f con satisfying: f.sub.con ≧d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}/0.006 wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.
Claim 19
Dependent Claim 229 words
An exposure apparatus which comprises: a light source system for generating illumination light; an optical integrator comprised of lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system, a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator being represented by 2d; a variable aperture stop arranged on a position where said plurality of light source images are formed, maximum and minimum values of an effective diameter of said variable aperture stop being respectively represented by 2R max and 2R min , and average values of irradiance on the mask surface respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values being represented by E max and E min ; and a condenser optical system for guiding the light beams from said optical integrator to a mask surface, a focal length of said condenser optical system being represented by f con ; and a projection optical system for exposing a pattern on the mask surface onto an object to be exposed, a projection magnification of said projection optical system represented by B satisfying: B≧d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}/(0.03·f.sub.con) wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.
Claim 20
Dependent Claim 229 words
An exposure apparatus which comprises: a light source system for generating illumination light; an optical integrator comprised of lens elements each having a predetermined size, and forms a plurality of light source images on the basis of the light beam from said light source system, a width, in a predetermined direction, of each of a plurality of lens elements constituting said optical integrator being represented by 2d; a variable aperture stop arranged on a position where said plurality of light source images are formed, maximum and minimum values of an effective diameter of said variable aperture stop being respectively represented by 2R max and 2R min , and average values of irradiance on the mask surface respectively obtained when the effective diameter of said variable aperture stop assumes the maximum and minimum values being represented by E max and E min ; and a condenser optical system for guiding the light beams from said optical integrator to a mask surface, a focal length of said condenser optical system being represented by f con ; and a projection optical system for exposing a pattern on the mask surface onto an object to be exposed, a projection magnification of said projection optical system represented by B satisfying: B≧d{(R.sub.max.sup.2 E.sub.min)/(E.sub.max R.sub.min.sup.2)-1}/(0.03·f.sub.con) wherein d is a half width, in a predetermined direction, of each a plurality of lens elements constituting said optical integrator.

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