Patent ID: 7952780

Claim:
A microactuator that drives a plurality of mirror elements of an optical device used to expose a substrate in a lithography process, the microactuator comprising: a plurality of support members that respectively support the plurality of mirror elements of the optical device, each support member having an elastic section in a part thereof; and a plurality of drive mechanisms respectively corresponding to the plurality of support members, wherein each of the plurality of drive mechanisms changes a distance between a support point at which the corresponding support member supports the respective mirror element and a predetermined reference plane, by transforming the elastic section of the corresponding support member, and the microactuator controls each drive mechanism to thereby control the distance between the support point at which the corresponding support member supports the respective mirror element and the predetermined reference plane, to thereby switch a state of the respective mirror element between a first ON state where a reflection surface of the respective mirror element is positioned on a first plane that is parallel to a predetermined reference plane and is a first predetermined distance away from the reference plane, a second ON state where the reflection surface of the respective mirror element is positioned on a second plane that is parallel to the reference plane and is a second predetermined distance away from the reference plane, and an OFF state where the reflection surface of the respective mirror element is inclined with respect to the reference plane, the second predetermined distance being different from the first predetermined distance, wherein when the respective mirror element is in the first ON state, illumination light reflected by the respective mirror element is incident on a projection optical system, when the respective mirror element is in the second ON state, illumination light reflected by the respective mirror element is incident on the projection optical system and a phase of the illumination light shifts from a phase of the illumination light reflected when the respective mirror element is in the first ON state, and when the respective mirror element is in the OFF state, illumination light reflected by the respective mirror element is not incident on the projection optical system.