Device for Transmission Image Detection for Use in a Lithographic Projection Apparatus and a Method for Determining Third Order Distortions of a Patterning Device and/or a Projection System of Such a Lithographic Apparatus
AssigneeASML Netherlands B.V.
InventorHaico Victor KOK
Life of this patent
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Abstract
Embodiments of the invention relate to a device for transmission image detection for use in a lithographic projection apparatus. In an embodiment, the device includes an array of gratings and an array of radiation sensitive sensors, each of which is arranged to receive radiation coming through one of the gratings. The array of radiation sensitive sensors may be a 1-dimensional diode array.
Claims10
A device for transmission image detection for use in a lithographic projection apparatus, said device comprising an array of gratings and an array of radiation sensitive sensors, each of which is arranged to receive radiation coming through one of said gratings.
A lithographic apparatus comprising:
- an illumination system configured to condition a radiation beam;
- a patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam, said patterning device comprising an array of first gratings;
- a substrate table constructed to hold a substrate;
- a projection system configured to project the patterned radiation beam onto a target portion of the substrate,
- a device for transmission image detection arranged on said substrate table, said device for transmission image detection comprising an array of second gratings and an array of radiation sensitive sensors each of which is arranged to receive radiation coming through one of said first gratings and through one of said second gratings;
- and
- a processing device arranged to calculate third order distortions of at least one of said patterning device and said projection system using signals received from said radiation sensitive sensors.
A method for determining third order distortions of at least one of a patterning device and a projection system of a lithographic apparatus, said method comprising:
- creating a radiation beam;
- imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam using a patterning device, said patterning device comprising an array of gratings;
- providing a device for transmission detection on said substrate, said device for transmission detection comprising an array of gratings and an array of radiation sensitive sensors arranged to receive radiation coming through said gratings and to produce measurement signals;
- sensing radiation coming through said gratings of said patterning device and through said gratings of said device for transmission detection;
- and
- determining third order distortions of at least one of said patterning device and said projection system, using said measurement signals.
Dependencies are inferred from the claim text.