Patent ID: 9612539
Date: 2017-04-04
CPC Classifications: G03F

Claim:
1. An exposure apparatus that exposes a substrate via a projection optical system, the apparatus comprising: a substrate stage that holds the substrate; a drive system that drives the substrate stage; a measurement system that has a plurality of heads and measures positional information of the substrate stage in a first direction and a second direction orthogonal to each other in a predetermined plane orthogonal to an optical axis of the projection optical system, the plurality of heads each irradiating a measurement beam to a grating section from a direction intersecting the predetermined plane, and the grating section being placed substantially parallel to the predetermined plane; and a controller that controls a drive of the substrate stage by the drive system based on the positional information measured by the measurement system, and in order to switch a drive control of the substrate stage using three heads that face the grating section, of the plurality of heads, to a drive control of the substrate stage using three heads including another head instead of one head of the three heads used before the switching, decides positional information to be measured by the another head based on the positional information measured by the three heads used before the switching, the another head being different from the three heads used before the switching, wherein the controller is capable of performing decision of the positional information for the switching of the drive control, by switching between a first decision method and a second decision method, in the first decision method, of a counter value and a phase offset in the another head, only the counter value is reset, and in the second decision method the counter value and the phase offset are reset.