Inspection method and apparatus, lithographic apparatus, lithographic processing cell and device manufacturing method
AssigneeASML Netherlands B.V.
InventorsArie Jeffrey Den Boef, Stanislav Y. Smirnov, Adel Joobeur
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Abstract
A scatterometer has a radiation source capable of emitting radiation in distinct first and second wavelength ranges. An adjustable optical element is provided to effect a chromatic correction as necessary according to which wavelength range is in use. A single scatterometer can thereby effect measurements using widely separated wavelengths.
Claims20
An inspection apparatus configured to determine a value related to a parameter of a target pattern printed on a substrate by a lithographic process used to manufacture a device layer on a substrate, the apparatus comprising:
- a radiation source arranged to selectively emit a first beam of radiation having a first wavelength in a first wavelength range or a second beam of radiation having a second wavelength in a second wavelength range, the second wavelength range being distinct from the first wavelength range;
- an optical system arranged to direct the selected one of the first or second beams of radiation on to the target pattern and to project radiation redirected by the target pattern onto a detector to obtain a scatterometric spectra;
- and
- an adjustable optical element arranged to selectively effect a chromatic correction of the optical system according to whether the first or second beam of radiation is emitted by the radiation source.
A lithographic apparatus, comprising:
- an illumination optical system arranged to illuminate a pattern;
- a projection optical system arranged to project an image of the pattern on to a substrate;
- and
- an inspection apparatus configured to determine a value related to a parameter of a target pattern printed on a substrate by a lithographic process used to manufacture a device layer on a substrate, the apparatus comprising:
- an optical system arranged to direct a first beam of radiation having a first wavelength in a first wavelength range or a second beam of radiation having a second wavelength in a second wavelength range on to the target pattern and to project radiation redirected by the target pattern onto a detector to obtain a scatterometric spectra, the second wavelength range being distinct from the first wavelength range, and
- an adjustable optical element arranged to selectively effect a chromatic correction of the optical system according to whether the first or second beam of radiation is directed by the optical system.
A lithographic cell comprising:
- a coater arranged to coat a substrate with a radiation sensitive layer;
- a lithographic apparatus arranged to expose an image onto the radiation sensitive layer of the substrate coated by the coater;
- a developer arranged to develop the image exposed by the lithographic apparatus;
- and
- an inspection apparatus configured to determine a value related to a parameter of a target pattern printed on a substrate by a lithographic process used to manufacture a device layer on a substrate, the apparatus comprising:
- a radiation source arranged to selectively emit a first beam of radiation having a first wavelength in a first wavelength range or a second beam of radiation having a second wavelength in a second wavelength range, the second wavelength range being distinct from the first wavelength range,
- an optical system arranged to direct the selected one of the first or second beams of radiation on to the target pattern and to project radiation redirected by the target pattern onto a detector to obtain a scatterometric spectra, and
- an adjustable optical element arranged to selectively effect a chromatic correction of the optical system according to whether the first or second beam of radiation is emitted by the radiation source.
An inspection method to determine a value related to a parameter of a target pattern printed on a substrate by a lithographic process used to manufacture a device layer on a substrate, the method comprising:
- controlling a radiation source to selectively emit a first beam of radiation having a first wavelength in a first wavelength range or a second beam of radiation having a second wavelength in a second wavelength range, the second wavelength range being distinct from the first wavelength range;
- using an optical system to direct the selected one of the first or second beams of radiation on to the target pattern and to project radiation redirected by the target pattern onto a detector to obtain a scatterometric spectra;
- and
- adjusting an adjustable optical element to selectively effect a chromatic correction of the optical system according to whether the first or second beam of radiation is emitted by the radiation source.
An inspection apparatus configured to determine a value related to a parameter of a target pattern printed on a substrate by a lithographic process used to manufacture a device layer on a substrate, the apparatus comprising:
- an optical system arranged to direct a first beam of radiation having a first wavelength in a first wavelength range or a second beam of radiation having a second wavelength in a second wavelength range, the second wavelength range being distinct from the first wavelength range, on to the target pattern and to project radiation redirected by the target pattern onto a detector to obtain a scatterometric spectra, the optical system comprising an objective lens having a pupil plane and arranged to collect the radiation redirected by the target pattern and an imaging optical system arranged to project an image of the pupil plane onto the detector;
- and
- an adjustable optical element arranged to selectively effect a chromatic correction of the optical system according to whether the first or second beam of radiation is directed by the optical system.
Dependencies are inferred from the claim text.