Projection exposure method and apparatus
AssigneeNikon Corporation
InventorNaomasa Shiraishi
Life of this patent
Estimating the term…
Abstract
In projection exposure of isolated pattern such as a contact hole, in order to increase the depth of focus a coherence reducing member is disposed on a Fourier transform plane in an image-forming optical path between a mask and a sensitized base, so that coherence is reduced between image-forming beams respectively passing through a plurality of different, concentric regions around the optical axis of the projection optical system on the Fourier transform plane. The coherence reducing member may be a polarization state control member for making a difference in polarization state, a member for making a difference in optical path length, or space filters with different shapes.
Claims56
A projection exposure apparatus comprising:
- illuminating means for supplying illumination light to illuminate a mask having a fine pattern;
- a projection optical system for receiving emergent light from the pattern of said mask to project a focused image of said pattern onto a sensitized base;
- and
- polarization state control means disposed on a Fourier transform plane or on a close plane thereto in an image-forming optical path between said mask and said sensitized base, for making a mutual difference in polarization state between an image-forming beam passing through a circular region around an optical axis of said projection optical system on said Fourier transform plane or on the close plane thereto and an image-forming beam passing through a region outside said circular region.
A projection exposure apparatus comprising:
- illuminating means for supplying illumination light to illuminate a mask having a fine pattern;
- a projection optical system for receiving emergent light from the pattern of said mask to project a focused image of said pattern onto a sensitized base;
- and
- polarization state control means disposed on a Fourier transform plane or on a close plane thereto in an image-forming optical path between said mask and said sensitized base, for making a mutual difference in polarization state between an image-forming beam passing through a first annular region around an optical axis of said projection optical system on said Fourier transform plane or on the close plane thereto and an image-forming beam passing through a second annular region outside said first annular region.
A projection exposure apparatus comprising:
- illuminating means for supplying illumination light to illuminate a mask having a fine pattern;
- a projection optical system for receiving emergent light from the pattern of said mask to project a focused image of said pattern onto a sensitized base;
- first means disposed on a Fourier transform plane or on a close plane thereto in an image-forming optical path between said mask and said sensitized base, for making a mutual difference polarization state between a beam passing through a circular region around an optical axis of said projection optical system on said Fourier transform plane or on the close plane thereto and a beam passing through a region outside said circular region;
- and
- second means disposed in said illuminating means, for producing first illumination light and second illumination light having mutually different polarization properties and being temporally incoherent with each other.
A projection exposure apparatus comprising:
- illuminating means for supplying illumination light to illuminate a mask having a fine pattern;
- a projection optical system for receiving emergent light from the pattern of said mask to project a focused image of said pattern onto a sensitized base;
- first means disposed on a Fourier transform plane or on a close plane thereto in an image-forming optical path between said mask and said sensitized base, for making a mutual difference in polarization state between an image-forming beam passing through a first annular region around an optical axis of said projection optical system on said Fourier transform plane or on the close plane thereto and an image-forming beam passing through a second annular region outside said first annular region;
- and
- second means disposed in said illuminating means, for producing first illumination light and second illumination light having mutually different polarization properties and being temporally incoherent with each other.
A projection exposure apparatus comprising:
- illuminating means for supplying illumination light to illuminate a mask having a fine pattern;
- a projection optical system for receiving emergent light from the pattern of said mask to project a focused image of said pattern onto a sensitized base;
- and
- polarization state control means disposed on a Fourier transform plane or on a close plane thereto in an image-forming optical path between said mask and said sensitized base, for making a mutual difference in polarization state between a plurality of image-forming beams respectively passing through a plurality of concentric, different regions around an optical axis of said projection optical system on said Fourier transform plane or on the close plane thereto.
A projection exposure apparatus, comprising:
- a projection optical system which is disposed between a mask illuminated with an illumination light and a substrate exposed with said illumination light, and which emits light from a pattern of said mask onto said substrate;
- and
- a polarization member which is disposed between said mask and said substrate, and which transforms the light from said pattern into plural lights different from each other in polarization characteristics.
A method for uniformly illuminating a mask on which a fine pattern is formed, with illumination light for exposure having a predetermined range of incident angle and projecting the light from said mask as an image-forming beam through a projection optical system onto a sensitized base, whereby said sensitized base is subjected to exposure by a projected image of said pattern, comprising the steps of:
- separating the image-forming beam distributed, on a Fourier transform plane or on a close plane thereto in said projection optical system into a circular region around an optical axis of said projection optical system and an annular region surrounding said circular region;
- and
- making a polarization state of an image-forming beam passing through said circular region and reaching said sensitized base, different from a polarization state of an image-forming beam passing through said annular region and reaching said sensitized base.
A method for uniformly illuminating a mask on which a fine pattern is formed, with illumination light for exposure having a predetermined range of incident angle and projecting the light from said mask as an image-forming beam through a projection optical system onto a sensitized base, whereby said sensitized base is subjected to exposure by a projected image of said pattern, comprising the steps of:
- separating an image-forming beam distributed on a Fourier transform plane or on a close plane thereto in said projection optical system into a circular region around an optical axis of said projection optical system and a plurality of annular regions at least doubly surrounding said circular region;
- and
- making different from each other a polarization state of an image-forming beam passing through said circular region and reaching said sensitized base and polarization states of at least two image-forming beams out of a plurality of image-forming beams comprising image-forming beams respectively passing through said plurality of annular regions and reaching said sensitized base.
An method for uniformly illuminating a mask on which a fine pattern is formed, with illumination, light for exposure having a predetermined range of incident angle and projecting the light, from said mask as an image-forming beam through a projection optical system onto a sensitized base, whereby said sensitized base is subjected to exposure by a projected image of said pattern, comprising the steps of:
- separating an image-forming beam distributed on a Fourier transform plane or on a close plane thereto in said projection optical system into a plurality of different, concentric regions around an optical axis of said projection optical system;
- making a mutual difference between polarization states of at least two image-forming beams out of a plurality of image-forming beams respectively passing through said plurality of regions and reaching said sensitized base;
- and
- moving said sensitized base along the optical axis of said projection optical system in a period between an exposure start and an exposure end in exposure of said sensitized base.
A projection exposure method of illuminating a mask formed with a pattern to project light from said pattern onto a substrate, comprising:
- transforming the light from said pattern into plural lights different from each other in polarization characteristic by a polarization member disposed between said mask and said substrate;
- and projecting the transformed plural lights onto said substrate.
A method of making an exposure apparatus, comprising:
- disposing a projection optical system between a mask and a substrate, said projection optical system projecting light from a pattern of said mask onto said substrate;
- and disposing a polarization member between said mask and said substrate, said polarization member transforming the light from said pattern into plural lights different from each other in polarization characteristic.
A method of producing a semiconductor integrated circuit by a projection exposure apparatus which illuminates a mask formed with a pattern to project light from said pattern onto a substrate, comprising:
- transforming the light from said pattern into plural lights different from each other in polarization characteristic by a polarization member disposed between said mask and said substrate;
- and exposing said substrate with said plural lights different in polarization characteristic to produce a semiconductor device.
Dependencies are inferred from the claim text.