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

Patent metadata

Field	Value
Publication number	US-9465294-B2
Application number	US-201414560026-A
Country	US
Kind code	B2
Filing date	Dec 4, 2014
Priority date	Dec 25, 2013
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

The present invention provides an optical apparatus that deforms a reflecting surface of a mirror, comprising a base plate, a fixing member configured to fix a part of the mirror including a center of the mirror to the base plate, and a plurality of actuators each having a first end connected to the mirror and a second end connected to the base plate, and configured to apply force to a back face of the mirror, wherein the plurality of actuators include a plurality of first actuators and a plurality of second actuators, and the plurality of first actuators are arranged such that a distance between each first actuator and the center of the mirror is longer than half of a distance between the center and a periphery of the mirror.

First claim

What is claimed is:

1. An optical apparatus that deforms a reflecting surface of a mirror, comprising:
a base plate;
a fixing member configured to fix a part of the mirror, the part including a center of the mirror, to the base plate; and
a plurality of actuators for deforming the reflecting surface of the mirror,
wherein each of the plurality of actuators has a first end connected to the mirror and a second end connected to the base plate, and is configured to apply force to a back face on an opposite side of the reflecting surface,
the plurality of actuators include a plurality of first actuators and a plurality of second actuators for deforming the reflecting surface of the mirror,
a distance between the first end and the second end of the second actuator changes greater than that of the first actuator when receiving a unit amount of external force, and
the plurality of first actuators are arranged such that a distance between each first actuator and the center of the mirror is longer than half of a distance between the center of the mirror and a periphery of the mirror.

2. The optical apparatus according to claim 1 ,
wherein the plurality of first actuators and the plurality of second actuators are arranged such that the distance between each first actuator and the center of the mirror is larger than or equal to a largest value among distances between the respective second actuators and the center of the mirror.

3. The optical apparatus according to claim 1 ,
wherein the plurality of first actuators are arranged such that distances between the respective first actuators and the center of the mirror are equal to one another.

4. The optical apparatus according to claim 1 ,
wherein the plurality of first actuators are arranged such that ratios of the distances between the respective first actuators and the center of the mirror to the distance between the center of the mirror and the periphery of the mirror are equal to one another.

5. The optical apparatus according to claim 1 ,
wherein the number of first actuators is smaller than the number of second actuators.

6. The optical apparatus according to claim 1 ,
wherein the plurality of first actuators include four first actuators arranged at an equal angular interval with respect to the center of the mirror.

7. The optical apparatus according to claim 1 , further comprising:
a measurement unit configured to measure a shape of the reflecting surface; and
a control unit configured to control driving of the first actuators and the second actuators, based on a deviation between the shape of the reflecting surface measured by the measurement unit and a target shape.

8. The optical apparatus according to claim 1 , further comprising:
a sensor configured to detect information indicating driving status of each of the plurality of first actuators; and
a control unit configured to control driving of the first actuators and the second actuators, based on output from the sensor.

9. The optical apparatus according to claim 1 ,
wherein each first actuator applies force to the back face by deforming so as to change the distance between the first end and the second end thereof.

10. The optical apparatus according to claim 9 ,
wherein each first actuator includes at least one of a piezoelectric actuator, a magnetostrictive actuator, and a screw member.

11. The optical apparatus according to claim 1 ,
wherein each second actuator has a stator and a movable element that do not come into contact with each other, and
one of the stator and the movable element is connected to the back face, and the other is connected to the base plate.

12. The optical apparatus according to claim 11 ,
wherein each second actuator includes at least one of a linear motor, an electrostatic actuator, and an electromagnet.

13. An optical apparatus that deforms a reflecting surface of a mirror, comprising:
a base plate;
a fixing member configured to fix a part of the mirror, the part including a center of the mirror, to the base plate; and
a plurality of actuators for deforming the reflecting surface of the mirror,
wherein each of the plurality of actuators has a first end connected to the mirror and a second end connected to the base plate, and is configured to apply force to a back face on an opposite side of the reflecting surface,
the plurality of actuators include a plurality of first actuators and a plurality of second actuators for deforming the reflecting surface of the mirror,
a distance between the first end and the second end of the second actuator changes greater than that of the first actuator when receiving a unit amount of external force, and
the plurality of first actuators and the plurality of second actuators are arranged such that the distance between each first actuator and the center of the mirror is larger than or equal to a largest value among distances between the respective second actuators and the center of the mirror.

14. A projection optical system that projects a mask pattern onto a substrate, including an optical apparatus that deforms a reflecting surface of a mirror, the optical apparatus comprising:
a base plate;
a fixing member configured to fix a part of the mirror, the part including a center of the mirror, to the base plate; and
a plurality of actuators for deforming the reflecting surface of the mirror,
wherein each of the plurality of actuators has a first end connected to the mirror and a second end connected to the base plate, and is configured to apply force to a back face on an opposite side of the reflecting surface,
the plurality of actuators include a plurality of first actuators and a plurality of second actuators for deforming the reflecting surface of the mirror,
a distance between the first end and the second end of the second actuator changes greater than that of the first actuator when receiving a unit amount of external force, and
the plurality of first actuators are arranged such that a distance between each first actuator and the center of the mirror is longer than half of a distance between the center of the mirror and a periphery of the mirror.

15. An exposure apparatus that exposes a substrate, including a projection optical system that projects a mask pattern onto a substrate, the projection optical system including an optical apparatus that deforms a reflecting surface of a mirror, the optical apparatus comprising:
a base plate;
a fixing member configured to fix a part of the mirror, the part including a center of the mirror, to the base plate; and
a plurality of actuators for deforming the reflecting surface of the mirror,
wherein each of the plurality of actuators has a first end connected to the mirror and a second end connected to the base plate, and is configured to apply force to a back face on an opposite side of the reflecting surface,
the plurality of actuators include a plurality of first actuators and a plurality of second actuators for deforming the reflecting surface of the mirror,
a distance between the first end and the second end of the second actuator changes greater than that of the first actuator when receiving a unit amount of external force, and
the plurality of first actuators are arranged such that a distance between each first actuator and the center of the mirror is longer than half of a distance between the center of the mirror and a periphery of the mirror.

16. A method of manufacturing an article, the method comprising:
forming a pattern on a substrate using an exposure apparatus; and
processing the substrate, on which the pattern has bee

Assignees

• Canon Kk

Inventors

• Sai Choshoku

Classifications

• G03F7/2008 Primary

  characterised by the reflectors, diffusers, light or heat filtering means or anti-reflective means used · CPC title

• G02B26/0825

  the reflecting element being a flexible sheet or membrane, e.g. for varying the focus (flexible mirrors for cosmetic use A45D42/24) · CPC title

• G02B26/06 Primary

  for controlling the phase of light (G02B26/08 takes precedence {, measuring optical phase difference G01J9/00}) · CPC title

• G03F7/70266

  Adaptive optics, e.g. deformable optical elements for wavefront control, e.g. for aberration adjustment or correction · CPC title

• H10P76/00

  Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography · CPC title