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US 2014/0211185 A1Published application
Inspection Apparatus, Lithographic Apparatus, Lithographic Processing Cell and Inspection Method
AssigneeASML Netherlands B.V.
InventorsHugo Augustinus Joseph Cramer, Antoine Gaston Marie Kiers, Henricus Petrus Maria Pellemans
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Abstract
For angular resolved spectrometry a radiation beam is used having an illumination profile having four quadrants is used. The first and third quadrants are illuminated whereas the second and fourth quadrants aren't illuminated. The resulting pupil plane is thus also divided into four quadrants with only the zeroth order diffraction pattern appearing in the first and third quadrants and only the first order diffraction pattern appearing in the second and third quadrants.
Claims20
An inspection apparatus comprising:
- an illumination system configured to:
- provide a radiation beam comprising an illumination profile, wherein:
- the illumination profile comprises two quadrants spaced apart from each other, the two quadrants being substantially illuminated, and
- an intensity distribution of the radiation beam is asymmetric about an imaginary line in a pupil plane of the illumination system, and
- illuminate a structure on a surface of the substrate;
- and
- a detector configured to:
- detect the radiation beam reflected from the structure illuminated on the surface of the substrate;
- and
- separately detect a zeroth diffraction order and a higher diffraction order from the pupil plane, wherein at least one characteristic of the structure is reconstructed using the separately detected zeroth diffraction order and the higher diffraction order.
7 more elements
A lithographic apparatus comprising:
- an illumination optical system configured to illuminate a pattern;
- a projection optical system configured to project an image of the pattern on to a substrate;
- and
- an inspection apparatus configured to reconstruct a structure on a surface of the substrate, the inspection apparatus comprising:
- an illumination system configured to:
- provide a radiation beam comprising an illumination profile, wherein:
- the illumination profile comprises two quadrants spaced apart from each other, the two quadrants being substantially illuminated, and
- an intensity distribution of the beam of radiation is asymmetric about an imaginary line in a pupil plane of the illumination system, and
- illuminate a structure on a surface of the substrate;
- and
- a detector configured to:
- detect the beam of radiation reflected from the illuminated structure on the surface of the substrate;
- and
- separately detect a zeroth diffraction order and a higher diffraction order from the pupil plane, wherein at least one characteristic of the structure is reconstructed using the separately detected zeroth diffraction order and the higher diffraction order.
11 more elements
A lithographic cell comprising:
- a coater configured to coat a substrate with a radiation sensitive layer;
- a lithographic apparatus configured to expose images onto the radiation sensitive layer of the substrate coated by the coater;
- a developer configured to develop images exposed by the lithographic apparatus;
- and
- an inspection apparatus configured to reconstruct a structure on a surface of the substrate, the inspection apparatus comprising:
- an illumination system configured to:
- provide a radiation beam comprising an illumination profile, wherein:
- the illumination profile comprises two quadrants spaced apart from each other, the two quadrants being substantially illuminated, and
- an intensity distribution of the radiation beam is asymmetric about an imaginary line in a pupil plane of the illumination system, and
- illuminate a structure on a surface of the substrate;
- and
- a detector configured to:
- detect the beam of radiation reflected from the illuminated structure on the surface of the substrate;
- and
- separately detect a zeroth diffraction order and a higher diffraction order from the pupil plane, wherein at least one characteristic of the structure is reconstructed using the separately detected zeroth diffraction order and the higher diffraction order.
12 more elements
Dependencies are inferred from the claim text.