Patent ID: 8902405
Filing Date: 2014-12-02
Classification: G01B,G03F

Abstract:
1. A stage apparatus comprising: a base portion; a table capable of moving along an X-Y plane defined in an X-Y-Z coordinate system; a first Y-axis interferometer which is supported by the base portion so as to have a first measurement optical path in a Y-axis direction of the X-Y-Z coordinate system, and configured to detect measurement light which passes through the first measurement optical path, is reflected by a first end surface of the table, and travels back along the first measurement optical path, thereby measuring a position of the first end surface in the Y-axis direction; a second Y-axis interferometer which is supported by the base portion so as to have a second measurement optical path in the Y-axis direction, and configured to detect measurement light which passes through the second measurement optical path, is reflected by a second end surface of the table, that is opposite to the first end surface in the Y-axis direction, and travels back along the second measurement optical path, thereby measuring a position of the second end surface in the Y-axis direction; a third Y-axis interferometer which is supported by the base portion so as to have a third measurement optical path in the Y-axis direction and be spaced apart from the first Y-axis interferometer and the second Y-axis interferometer in an X-axis direction of the X-Y-Z coordinate system, and configured to detect measurement light returned from a round trip along the third measurement optical path, thereby measuring a distance between the first Y-axis interferometer and the second Y-axis interferometer in the Y-axis direction; and a control unit configured to obtain a deformation amount of the table based on the measurement value obtained by the first Y-axis interferometer, the measurement value obtained by the second Y-axis interferometer, and the measurement value obtained by the third Y-axis interferometer, and obtain a corrected target position by correcting a target position of the table based on the deformation amount of the table, thereby positioning the table so that a position of the table, which is obtained from the measurement value obtained by the first Y-axis interferometer, and the measurement value obtained by the second Y-axis interferometer, is set at the corrected target position, wherein the third Y-axis interferometer includes: a Y-axis reflecting mirror which is supported by the base portion so that a Y-axis coordinate and Z-axis coordinate thereof in the X-Y-Z coordinate system are identical to a Y-axis coordinate and Z-axis coordinate of the second Y-axis interferometer in the X-Y-Z coordinate system, and is configured to reflect the measurement light which passes through the third measurement optical path, and a detection unit which is supported by the base portion so that a Y-axis coordinate and Z-axis coordinate thereof in the X-Y-Z coordinate system are identical to a Y-axis coordinate and Z-axis coordinate of the first Y-axis interferometer in the X-Y-Z coordinate system, and is configured to detect the measurement light which is reflected by the Y-axis reflecting mirror, and travels back along the third measurement optical path.