Advanced illumination system for use in microlithography
AssigneeASML US, Inc.
InventorsMark Oskotsky, Lev Ryzhikov, Scott Coston, James Tsacoyeanes, Walter Augustyn
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Abstract
A system for microlithography comprises an illumination source; an illumination optical system including, in order from an objective side, (a) a first diffractive optical element that receives illumination from the illumination source, (b) a zoom lens, (c) a second diffractive optical element, (d) a condenser lens, (e) a relay lens, and (f) a reticle, and a projection optical system for imaging the reticle onto a substrate, wherein the system for microlithography provides a zoomable numerical aperture.
Claims81
A system for microlithography comprising:
- an illumination source;
- an illumination optical system including, in order from an objective side:
- (a) a first diffractive optical element that receives illumination from said illumination source;
- (b) a zoom lens;
- (c) a second diffractive optical element;
- (d) a condenser lens;
- (e) a relay lens;
- (f) a reticle;
- and
- a projection optical system that images said reticle onto a substrate,
- wherein said system for microlithography provides a zoomable numerical aperture.
A system for microlithography comprising:
- an illumination source;
- an illumination optical system that receives illumination from said illumination source;
- and
- a projection optical system that receives illumination from said illumination system,
- wherein a ratio of a numerical aperture of said illumination system and a numerical aperture of said projection optical system is continuously variable while a field size is discretely variable.
An illumination system for microlithography comprising, in order from an objective side:
- a first diffractive optical element;
- a zoom lens;
- a second diffractive optical element having a rectangular numerical aperture;
- a condenser lens;
- and
- a relay lens.
A system for microlithography comprising:
- an illumination system including, in order from an objective side:
- (a) a zoom lens having a first diffractive optical element on a first side, and a second diffractive optical element on a second side;
- (b) a condenser lens;
- (c) a relay lens;
- and
- a projection optical system,
- wherein a partial coherence of said system for microlithography is continuously variable.
A method of exposing a substrate comprising the steps of:
- illuminating an illumination optical system that includes, in order from an objective side:
- (a) a first diffractive optical element that receives illumination from the illumination source;
- (b) a zoom lens;
- (c) a second diffractive optical element;
- (d) a condenser lens;
- (e) a relay lens;
- (f) a reticle;
- forming a zoomable numerical aperture beam at a plane of the reticle;
- and
- projecting the beam formed in the plane of the reticle onto the substrate through a projection optical system.
A method of exposing a substrate comprising the steps of:
- illuminating an illumination system that includes, in order from an objective side:
- (a) a zoom lens having a first diffractive optical element on a first side, and a second diffractive optical element on a second side;
- (b) a condenser lens;
- (c) a relay lens;
- and
- projecting a beam formed by the relay lens onto the wafer using a projection optical system;
- and
- continuously varying a partial coherence of an illumination optical system/projection optical system combination.
Dependencies are inferred from the claim text.