Patent ID: 8928882
Filing Date: 2015-01-06
Classification: G03F

Abstract:
1. A measurement apparatus which measures a position of a second object 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 an alignment scope configured to measure the position of the second object by detecting a plurality of alignment marks provided on the second object, where a length, in an array direction of the first head and the second head, of a region in which the plurality of alignment marks are provided is equal to or larger than an interval between the first head and the second head, 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 detection process of positioning the second object so that the alignment scope detects each of the plurality of alignment marks, thereby detecting a position on the diffraction grating by each of the first head and the second head, 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, using the position detected by the first head or the second head in the detection process as a reference position, 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.