Exposure apparatus and positioning method

摘要

An exposure apparatus exposes a pattern formed on a mask to a substrate having an alignment with a difference in level and a photosensitive material applied on the surface of the substrate. The exposure apparatus includes a stage adapted to hold the substrate and two-dimensionally movable in a predetermined plane; a sensor held in a predetermined relationship with respect to the plane and outputting a signal which varies in response to a relative movement between the sensor and the substrate in a direction perpendicular to the plane; a position detecting device for detecting the position of the stage; an arithmatic unit for calculating the position of the alignment mark on the basis of information from the position detecting device and an output outputted from the sensor when the stage and the sensor are moved relative to each other; and a control system for controling movement of the stage on the basis of the position of the alignment mark. A method is also provided for positioning of and measurement of alignment marks formed on a substrate.