Patent ID: 9372414
Filing Date: 2016-06-21
CPC Classification: G01B,G01D,G03F,Y10T

Claim Text:
1. An exposure method of exposing a substrate, via a projection optical system, with illumination light irradiated onto a mask via an illumination optical system, the method comprising: moving the mask with a mask stage system that has a first movable body and a first motor, the first movable body being placed above the projection optical system supported by a frame member of a body and holding the mask, and the first motor driving the first movable body; measuring positional information of the first movable body that is driven by the first motor, with a first encoder system that has a plurality of first heads each irradiating a first measurement beam to a first grating section having a reflection type grating, the reflection type grating being placed substantially parallel to a predetermined plane orthogonal to an optical axis of the projection optical system; moving the substrate with a substrate stage system that has a second movable body and a second motor, the second movable body being placed below the projection optical system and holding the substrate, and the second motor driving the second movable body; measuring positional information of the second movable body that is driven by the second motor, with a second encoder system that has four second heads each irradiating a second measurement beam to a second grating section having four scales, the four scales each having a reflection type grating placed substantially parallel to the predetermined plane; and controlling a drive of the first movable body by the first motor based on measurement information of the first encoder system and also controlling a drive of the second movable body by the second motor based on measurement information of the second encoder system so that the mask and the substrate are each moved relative to the illumination light in a scanning exposure of the substrate, wherein the plurality of first heads include two first heads that are different in position in a first direction which is orthogonal to the optical axis of the projection optical system and in which the mask is moved in the scanning exposure, and one first head that is different in position from the two first heads in a second direction orthogonal to the optical axis and orthogonal to the first direction, at least in an exposure operation of the substrate, a relationship between the second grating section and the four second heads changes between a first state and a second state by a movement of the second movable body, wherein, at least during the scanning exposure, three scales of the four scales are always faced by three of the four second heads.