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US 2006/0215140 A1Published application
Method of measuring the performance of an illumination system
OwnerPeter Dirksen, Casparus Antonius Juffermansinventors
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Abstract
The performance of an illumination system in, for example, a lithographic projection apparatus can be measured accurately and reliably by means of a test object (55) comprising at least one Fresnel zone lens (30) and an associated reference mark, preferably a ring (40). By superposed imaging of these and detecting and evaluating the composed image (56), telecentricity errors and aberrations of the illumination can be measured.
Claims41
A method of measuring the performance of an illumination system, which comprises a radiation source and is used in an imaging apparatus, which method comprises the steps of:
- providing a test object comprising at least one Fresnel zone lens;
- arranging the test object in the object plane of the imaging apparatus;
- imaging a test object area comprising a Fresnel zone lens in an image plane by means of an illumination beam supplied by the illuminating system and by means of the imaging system of the apparatus, whereby a local effective source is imaged in the image plane;
- evaluating the image of the local effective source by means of a detection device and associated processing means to determine the performance of the illumination system, characterized in that the step of providing a test object comprises providing a test object having for each Fresnel zone lens a reference mark and in that the step of imaging comprises imaging of a Fresnel zone lens area and the corresponding reference mark area within the field of view of the detection device.
1 more element
Dependencies are inferred from the claim text.