Optical position assessment apparatus and method
First Claim
1. An optical position measurement apparatus, comprising:
- an illumination system that supplies a beam of radiation;
a substrate table that supports a substrate;
a projection system that projects the beam of radiation onto a target portion of the substrate;
a positioning system that causes relative movement between the substrate and the projection system; and
a measurement system that determines a position of at least a component of the projection system relative to the substrate, the measurement system comprising, an array of lenses arranged such that each lens in the array focuses a respective portion of the beam onto a respective part of the target portion, an array of detectors arranged such that each detector in the array detects light reflected from the substrate through a respective lens in the array and provides an output representative of an intensity of light reflected to the detector from the substrate through the respective lens, and a processor connected to the outputs of the detectors for deriving data representing the position of the lens array relative to the substrate from the outputs of the detectors.
1 Assignment
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Accused Products
Abstract
An optical position assessment apparatus and method has an illumination system that supplies an alignment beam of radiation, and positional data is derived from reflections of the alignment beam. A substrate is supported on a substrate table and a projection system is used to project the alignment beam onto a target portion of the substrate. A positioning system causes relative movement between the substrate and the projection system. An array of lenses is arranged such that each lens in the array focuses a respective portion of the alignment beam onto a respective part of the target portion. An array of detectors is arranged such that each detector in the array detects light reflected from the substrate through a respective lens in the array and provides an output representative of the intensity of light reflected to it from the substrate through the respective lens. A processor is connected to the outputs of the detectors for deriving data representing the position of the lens array relative to the substrate from the outputs of the detectors.
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Citations
44 Claims
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1. An optical position measurement apparatus, comprising:
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an illumination system that supplies a beam of radiation;
a substrate table that supports a substrate;
a projection system that projects the beam of radiation onto a target portion of the substrate;
a positioning system that causes relative movement between the substrate and the projection system; and
a measurement system that determines a position of at least a component of the projection system relative to the substrate, the measurement system comprising, an array of lenses arranged such that each lens in the array focuses a respective portion of the beam onto a respective part of the target portion, an array of detectors arranged such that each detector in the array detects light reflected from the substrate through a respective lens in the array and provides an output representative of an intensity of light reflected to the detector from the substrate through the respective lens, and a processor connected to the outputs of the detectors for deriving data representing the position of the lens array relative to the substrate from the outputs of the detectors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An optical position measuring method, comprising:
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producing an alignment beam of radiation;
projecting the alignment beam from a projection system onto a target portion of a substrate;
moving at least one of the substrate and the projection system relative to the other; and
determining a position of at least a component of the projection system relative to the substrate, the determining step comprising, illuminating an array of lenses arranged such that each lens in the array focuses a respective portion of the alignment beam onto a respective part of the target portion, detecting light reflected from the substrate through each respective lens in the array and providing an output representative of a detected intensity of light reflected from the substrate through each lens, and deriving data representing a position of the array of lenses relative to the substrate from the outputs. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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Specification