Projection exposure method and apparatus

• US 6,549,266 B1
• Filed: 07/02/1999
• Issued: 04/15/2003
• Est. Priority Date: 03/16/1993
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Taniguchi, Tetsuo
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): Kim, Peter B.
• Application Number:
  US09/346,704
• Time in Patent Office: 1,383 Days
• Field of Search: 355/53, 355/55, 355/67, 355/69, 355/71, 355/77, 359/618, 430/5
• US Class Current: 355/53
• CPC Class Codes: G03F 7/70091 Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
• CPC Class Codes: G03F 7/70241 Optical aspects of refractive lens systems, i.e. comprising only refractive elements
• CPC Class Codes: G03F 7/7025 Size or form of projection system aperture, e.g. aperture stops, diaphragms or pupil obscuration; Control thereof
• CPC Class Codes: G03F 7/70891 Temperature

Abstract

An exposure apparatus comprises an illumination optical system for irradiating an illuminating light onto a mask having a plurality of patterns for which pattern forming conditions differ from one another, and a projection optical system for projecting images of said plurality of patterns onto a photosensitive substrate, a device for compensating imaging errors of pattern images to be projected onto said substrate, and a control system for controlling the operation of said compensating device in accordance with imaging errors of said plurality of pattern images so that said plurality of pattern images may be projected in specified imaging characteristics.

Claims

1. An exposure method using a projection optical system, comprising:

arranging a mask having a plurality of patterns for which distributions of imaging light beams at a pupil of said projection optical system differ from one another at an object side of said projection optical system;

determining an amount of correction for an imaging error, said amount being common to said plurality of patterns projected, by said projection optical system, under imaging conditions which differ from one another in accordance with the distributions of said imaging light beams; and

driving an adjustment mechanism which adjusts imaging conditions of said plurality of pattern images to simultaneously change the imaging conditions of said plurality of pattern images in accordance with said amount of correction.

2. A method for manufacturing a microdevice by using a mask having a plurality of circuit patterns for which distributions of imaging light beams at a pupil of a projection optical system differ from one another, comprising:

arranging said mask on an object side of said projection optical system;

determining an amount of correction for an imaging error, said amount being common to images of said plurality of circuit patterns projected, by said projection optical system, under imaging conditions which differ from one another;

driving an adjustment mechanism which adjusts imaging conditions of said plurality of circuit pattern images to simultaneously change the imaging conditions of said plurality of circuit pattern images in accordance with said amount of correction; and

transferring said plurality of circuit pattern images onto a photosensitive substrate.

3. An exposure method comprising:

disposing a mask at an object side with respect to a projection optical system, said mask having a plurality of patterns which are projected onto a predetermined plane with imaging conditions which are different from each other;

calculating a correction value which is common to each of said imaging conditions, in order to correct each of the imaging conditions of the plurality of pattern images; and

driving an adjustment mechanism which adjusts imaging conditions of said plurality of pattern images based on the calculated correction value.

4. An exposure method according to claim 3, wherein said plurality of patterns differ in fineness from each other.

5. An exposure method according to claim 3, wherein said plurality of patterns include a pattern composed of a transmitting part and a light shielding part and a pattern having a phase shift member which shifts a phase of illumination light which illuminates said mask.

6. An exposure method according to claim 3, wherein said mask is illuminated with illuminating light from an illumination optical system;

and

said correction value is calculated in consideration of at least one of an illuminating condition of said illumination optical system and forming conditions of said patterns.

7. An exposure method according to claim 3, wherein said correction value is calculated based on an experiment or a simulation.

8. An exposure method according to claim 3, wherein said mask is illuminated with illuminating light from an illumination optical system;

and

said correction value is calculated based on an energy amount of said illumination optical system in consideration of an optical characteristic of said projection optical system which varies with time.

9. An exposure method according to claim 3, wherein said adjustment mechanism moves at least one of said mask and an optical element of said projection optical system.

10. An exposure method according to claim 3, wherein said adjustment mechanism changes a positional relationship between a photosensitive substrate on which said plurality of patterns are projected and an imaging surface of said projection optical system.

11. An exposure method according to claim 3, wherein said mask is illuminated with illuminating light from an illumination optical system;

and

said correction value is calculated in consideration of a distribution condition of said illuminating light within a pupil plane of said projection optical system and aberration of said projection optical system.

12. A method of manufacturing a microdevice employing the method according to claim 3.

13. An exposure method comprising:

disposing a mask formed with a first pattern and a second pattern, which is different in kind from said first pattern, at an object side with respect to a projection optical system, said first and second patterns to be projected by said projection optical system;

calculating an imaging error of said first pattern projected by said projection optical system and an imaging error of said second pattern projected by said projection optical system;

obtaining a correction value which is common to the calculated imaging error of said first pattern and the calculated imaging error of said second pattern; and

driving an adjustment mechanism which adjusts imaging conditions of said pattern images based on the obtained correction value.

14. An exposure method according to claim 13, wherein said first pattern is a pattern composed of a transmitting part and a light shielding part and said second pattern is a pattern having a phase shift member which shifts a phase of illumination light which illuminates said mask.

15. An exposure method according to claim 13, wherein said correction value is determined such that a depth of focus of said projection optical system with respect to said first pattern and a depth of focus of said projection optical system with respect to said second pattern have an overlapping range.

16. An exposure method according to claim 15, wherein when a size of said overlapping range is smaller than a reference size, a warning is generated.

17. A method of manufacturing a microdevice employing the method according to claim 13.

18. An exposure method comprising:

causing distribution conditions of imaging light fluxes, from a plurality of patterns which are different in kind, to be different from each other on a pupil plane of a projection optical system;

calculating a correction value based on said distribution conditions of imaging light fluxes in order to correct imaging conditions of images of each of said plurality of patterns, said correction value being common to the plurality of pattern images; and

driving an adjustment mechanism which adjusts imaging conditions of said plurality of pattern images based on the calculated correction value.

19. A method of manufacturing a microdevice employing the method according to claim 18.