POSITION DETECTING APPARATUS, ALIGNER USING THE SAME, AND POSITION DETECTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a position detecting apparatus capable of precise position detection when the reflectivity of an alignment mark is different. SOLUTION: This position detecting apparatus converts the optical signal of an alignment mark MXJ detected by an image sensing element 42X to a first time series signal by first scanning which faces a measurement direction +X, and converts the optical signal to a second time series signal by second scanning which faces a direction -X opposite to the measurement direction. After the respective gains of the first and second time series signals which are obtained in the above manner are adjusted, time phase error which has been generated at the time of the gain adjustment is eliminated, and the obtained time series signal is converted to a position signal.