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US 7,126,671 B2Granted
Lithographic apparatus and device manufacturing method
AssigneeASML Netherlands B.V.
InventorsHenrikus Herman Marie Cox, Dominicus Jacobus Petrus Adrianus Franken, Nicolaas Rudolf Kemper, Engelbertus Antonius Fransiscus Van Der Pasch, Martijn Johannes Verbunt, Lambertus Adrianus Van Den Wildenberg
Life of this patent
Estimating the term…
Abstract
In a projection system for EUV, the positions of mirrors are measured and controlled relative to each other, rather than to a reference frame. Relative position measurements may be made by interferometers or capacitive sensors mounted on rigid extensions of the mirrors.
Claims12
A lithographic apparatus, comprising:
- a radiation system configured to provide a beam of radiation;
- a support structure configured to support a patterning device that imparts said beam of radiation with a desired pattern;
- a substrate holder configured to hold a substrate;
- a projection system configured to project said patterned beam of radiation onto a target portion of said substrate;
- and
- a positioning system configured to maintain at least a first optical element and a second optical element in predetermined positions, said at least first and second optical elements being disposed in said radiation system and/or said projection system, said positioning system comprising:
- at least one position sensor that directly measures a relative position of at least said first optical element relative to said second optical element, and
- at least one interferometric displacement measuring device for measuring at least the relative position and orientation of said first and second optical elements,
- wherein the at least one of the first and second optical elements includes a rigid extension carrying a beam directing element for an interferometer beam of the interferometric displacement measuring device.
6 more elements
A device manufacturing method, comprising:
- providing a substrate;
- providing a beam of radiation using a radiation system;
- imparting a desired pattern onto said beam of radiation;
- projecting said patterned beam of radiation onto a target portion of said substrate via a projection system;
- maintaining a first optical element and a second optical element in predetermined positions by:
- directly measuring the relative positions of said first and second optical elements,
- employing an interferometer beam to measure at least the relative position and orientation of said first and second optical elements wherein the first and second optical elements include a rigid extension carrying a beam directing element for the interferometer beam, and
- controlling the positions of said first and second optical elements based on the direct measurement of their relative positions.
5 more elements
A lithographic positioning system, comprising:
- at least a first optical element and a second optical element situated in predetermined positions;
- at least one position sensor that directly measures a relative position of at least said first optical element relative to said second optical element;
- at least one interferometric displacement measuring device for measuring at least the relative position and orientation of said first and second optical elements, the at least one of the first and second optical elements including a rigid extension carrying a beam directing element for an interferometer beam of the interferometric displacement measuring device;
- a first actuator and a second actuator;
- a first controller and a second controller configured to respectively control said first and second actuators, said first controller being responsive to the measured relative position of said first optical element and said second controller being responsive to the measured relative position of said first and second optical elements;
- wherein said first and second actuators operate to maintain said first and second optical elements in a predetermined relative position.
3 more elements
Dependencies are inferred from the claim text.