Optical apparatus, projection optical system, exposure apparatus, and method of manufacturing article

A projection optical system for projecting a pattern of a mask onto a substrate, comprising:

• an optical apparatus for deforming a reflecting surface of a mirror, comprising:
• a base plate;
• a plurality of first actuators each having a first terminal connected to a surface opposite to the reflecting surface of the mirror and a second terminal connected to the base plate, and configured to apply a force to the surface opposite to the reflecting surface by deforming so as to change a distance between the first terminal and the second terminal;
• a plurality of second actuators each having rigidity lower than that of the first actuator, arranged between the mirror and the base plate, and configured to apply a force to the surface opposite to the reflecting surface;
• a sensor configured to detect information indicating a driving status of each of the plurality of first actuators;
• and
• a control unit configured to control, based on an output of the sensor, driving of each of the plurality of first actuators and driving of each of the plurality of second actuators so that a shape of the reflecting surface is changed to a target shape.

An exposure apparatus for exposing a substrate, comprising:

• a projection optical system for projecting a pattern of a mask onto a substrate, comprising:
• an optical apparatus for deforming a reflecting surface of a mirror, comprising:
• a base plate;
• a plurality of first actuators each having a first terminal connected to a surface opposite to the reflecting surface of the mirror and a second terminal connected to the base plate, and configured to apply a force to the surface opposite to the reflecting surface by deforming so as to change a distance between the first terminal and the second terminal;
• a plurality of second actuators each having rigidity lower than that of the first actuator, arranged between the mirror and the base plate, and configured to apply a force to the surface opposite to the reflecting surface;
• a sensor configured to detect information indicating a driving status of each of the plurality of first actuators;
• and
• a control unit configured to control, based on an output of the sensor, driving of each of the plurality of first actuators and driving of each of the plurality of second actuators so that a shape of the reflecting surface is changed to a target shape.

A method of manufacturing an article, the method comprising:

• exposing a substrate using an exposure apparatus;
• developing the exposed substrate;
• and
• processing the developed substrate to manufacture the article, wherein the exposure apparatus for exposing the substrate includes a projection optical system having an optical apparatus,
• wherein the optical apparatus for deforming a reflecting surface of a mirror includes:
• a base plate;
• a plurality of first actuators each having a first terminal connected to a surface opposite to the reflecting surface of the mirror and a second terminal connected to the base plate, and configured to apply a force to the surface opposite to the reflecting surface by deforming so as to change a distance between the first terminal and the second terminal;
• a plurality of second actuators each having rigidity lower than that of the first actuator, arranged between the mirror and the base plate, and configured to apply a force to the surface opposite to the reflecting surface;
• a sensor configured to detect information indicating a driving status of each of the plurality of first actuators;
• and
• a control unit configured to control, based on an output of the sensor, driving of each of the plurality of first actuators and driving of each of the plurality of second actuators so that a shape of the reflecting surface is changed to a target shape.