Control system, positioning system, lithographic apparatus, control method, device manufacturing method and control program
AssigneeASML Netherlands B.V.
InventorsMarinus Maria Johannes Van De Wal, Wilhelmus Henricus Theodorus Maria Aangenent, Jeroen Johannes Theodorus Hendrikus De Best, Jan Van Eijk
Life of this patent
Estimating the term…
Abstract
A control system for a positioning system, for positioning a driven object, e.g. in a lithographic apparatus, in N dimensions has M sensors, where M>N. A transformation module converts the M measurements by the sensors into a positional estimate in N dimensions taking into account compliance of the driven object.
Claims19
A control system configured to estimate a position in N dimensions of a point of interest on an object in a lithographic apparatus, where N is a positive integer, the system comprising:
- a measurement module configured to obtain M measurements, the M measurements relating to one or more measurement points on the object and at least one of the measurement points being displaced from the point of interest, M being a positive integer greater than N;
- and
- a transformation module configured to convert the M measurements into N positional estimate values representing an estimate of the position in the N dimensions of the point of interest, taking into account only static and low-frequency contributions of non-rigid body modes of the object.
A control method for estimating a position in N dimensions of a point of interest on an object, where N is a positive integer, the method comprising:
- obtaining M measurements, the M measurements relating to one or more measurement points on the object and at least one of the measurement points being displaced from the point of interest, M being a positive integer greater than N;
- and
- converting the M measurements into N positional estimate values representing an estimate of the position in the N dimensions of the point of interest, taking into account only static and low-frequency contributions of non-rigid body modes of the object.
A non-transitory computer-readable medium comprising a control program for estimating a position in N dimensions of a point of interest on an object, where N is a positive integer, the control program comprising code configured to instruct a computer to effect at least:
- control of a measurement system to obtain M measurements, the positional measurements relating to one or more measurement points on the object and at least one of the measurement points being displaced from the point of interest, M being a positive integer greater than N;
- and
- conversion of the M positional measurements into N positional estimate values representing an estimate of the position in the N dimensions of the point of interest, taking into account only static and low-frequency contributions of non-rigid body modes of the object.
Dependencies are inferred from the claim text.