Measurement apparatus, exposure apparatus, and device fabrication method
AssigneeCanon Kabushiki Kaisha
InventorNobuo IMAOKA
Life of this patent
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Abstract
The present invention provides a measurement apparatus which measures a position of a second object relative to a first object, the apparatus including a first measurement unit which includes a diffraction grating provided on the first object, and a first head and a second head provided on the second object, and is configured to measure the position of the second object relative to the first object by the first head or the second head, and a processing unit configured to perform a process of obtaining the position of the second object relative to the first object.
Claims8
A measurement apparatus which measures a position of a second abject relative to a first object, the apparatus comprising:
- a first measurement unit which includes a diffraction grating provided on the first object, and a first head and a second head provided on the second object, and is configured to measure the position of the second object relative to the first object by the first head or the second head;
- and
- a processing unit configured to perform a process of obtaining the position of the second object relative to the first object,
- wherein the processing unit performs
- a first process of obtaining a deformation amount of the diffraction grating by repeating a process, in which while a position on the diffraction grating previously detected by one head of the first head and the second head is positioned at the center of a field of view of the other head, a position different from the position on the diffraction grating previously detected by the one head is detected, until the one head detects an entire surface of the diffraction grating, and
- a second process of correcting the position of the second object relative to the first object, which is measured by the first head or the second head, based on the deformation amount of the diffraction grating.
A device fabrication method comprising steps of:
- exposing a substrate using an exposure apparatus;
- and
- performing a development process for the substrate exposed,
- wherein the exposure apparatus includes:
- a stage configured to hold the substrate;
- a measurement apparatus configured to measure a position of the stage relative to a reference frame, that defines an apparatus reference;
- and
- a positioning mechanism configured to position the stage based on the position of the stage relative to the reference frame, which is measured by the measurement apparatus,
- the measurement apparatus includes:
- a first measurement unit which includes a diffraction grating provided on the reference frame, and a first head and a second head provided on the stage, and is configured to measure the position of the stage relative to the reference frame by the first head or the second head;
- and
- a processing unit configured to perform a process of obtaining the position of the stage relative to the reference frame, and
- the processing unit performs a first process of obtaining a deformation amount of the diffraction grating by repeating a process, in which while a position on the diffraction grating previously detected by one head of the first head and the second head is positioned at the center of a field of view of the other head, a position different from the position on the diffraction grating previously detected by the one head is detected, until the one head detects an entire surface of the diffraction grating, and
- a second process of correcting the position of the stage relative to the reference frame, which is measured by the first head or the second head, based on the deformation amount of the diffraction grating.
Dependencies are inferred from the claim text.