Patent ID: 8842278

Claim:
An exposure apparatus which exposes an object with an illumination light via a projection optical system, the apparatus comprising: a frame structure configured to support the projection optical system; a base arranged below the projection optical system supported by the frame structure, a surface of the base being substantially parallel to a predetermined plane perpendicular to an optical axis of the projection optical system; a stage having a table configured to hold the object, the stage being provided on the base; a driving system having an electromagnetic motor, which drives the stage on the base by the electromagnetic motor, a part of the electromagnetic motor being provided at the stage; a measurement system having four heads provided at the table, which measures positional information of the table by irradiating a beam from below via each of the four heads onto a measurement plate, the measurement plate having four regions in which reflection type two-dimensional gratings are formed, respectively, and being supported by the frame structure so that the four regions are substantially parallel to the predetermined plane and are arranged around the optical axis of the projection optical system; and a controller configured to control the driving system based on the measured positional information, wherein the controller obtains correction information of a positional error between a first coordinate system defined by three of the four heads and a second coordinate system defined by one of the four heads different from the three heads and two of the three heads based on positional information measured by the measurement system within a movement area of the stage where the four heads face the four regions of the measurement plate, respectively, and the driving system is controlled based on the measured positional information and the correction information.