Vibration-compensated optical system, lithography apparatus and method

Patent metadata

Field	Value
Publication number	US-2016349623-A1
Application number	US-201615236602-A
Country	US
Kind code	A1
Filing date	Aug 15, 2016
Priority date	Mar 12, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

A vibration-compensated optical system for a lithography apparatus includes an optical element, a carrying element, an actuator for actuating the optical element relative to the carrying element, a first elastic element which directly couples the optical element to the carrying element, a reaction mass, and a second elastic element. The actuator couples the optical element to the reaction mass. The second elastic element directly couples the reaction mass to the carrying element. For a mass (m 1 ) of the optical element, a stiffness (k 1 ) of the first elastic element, a mass (m 2 ) of the reaction mass and a stiffness (k 2 ) of the second elastic element the following holds true:

m
1

m
2

=

k
1

k
2

.

First claim

What is claimed is:

1 . A system, comprising:
an optical element; a carrying element; an actuator configured to actuate the optical element relative to the carrying element; a first elastic element directly coupling the optical element to the carrying element; a reaction mass coupled to the optical element via the actuator; and a second elastic element directly coupling the reaction mass to the carrying element, wherein m 1 is a mass of the optical element, k 1 is a stiffness of the first elastic element, m 2 is a mass of the reaction mass, and k 2 is a stiffness of the second elastic element, and

m
1

m
2

=

k
1

k
2

2 . The system of claim 1 , wherein a ratio

m
1



k
2

m
2



k
1

is between 0.8 and 1.2.

3 . The system of claim 1 , wherein

k
1

m
1

2



π

=

k
2

m
2

2



π

≥

5




Hz
.

4 . The system of claim 1 , further comprising:
a first damping element coupling the optical element to the carrying element; and a second damping element coupling the reaction mass to the carrying element, wherein the first damping element has a damping (c 1 ), the second damping element has a damping (c 2 ), and

m
1

m
2

=

k
1

k
2

=

c
1

c
2

.

5 . The system of claim 4 , wherein at least one parameter is adaptable during operation of the system, and the at least one parameter is selected from the group consisting of the mass of the optical element, the stiffness of the first elastic element, the damping of the first damping element, the mass of the reaction mass, the stiffness of the second elastic element, and the damping of the second damping element.

6 . The system of claim 4 , wherein the system is configured so that, when the actuator actuates the optical element relative to the carrying element, a force on the carrying element resulting from the actuation is zero

7 . The system of claim 1 , wherein at least one element selected from the group consisting of the first elastic element and the second elastic element is selected from the group consisting of a bending spring and a torsion spring.

8 . The system of claim 1 , wherein at least one element selected from the group consisting of the first elastic element and the second elastic element is monolithic.

9 . The system of claim 1 , wherein the actuator is configured to generate oppositely oriented forces of identical magnitude that act on the optical element and the carrying element.

10 . The system of claim 1 , wherein the actuator is configured to couple the optical element and the reaction mass to each other in a contactless manner.

11 . The system of claim 1 , wherein the actuator comprises a Lorentz force motor.

12 . The system of claim 1 , further comprising:
a sensor configured to detect a position of the optical element relative to the carrying element; and a control device configured to control the actuator depending on the detected position.

13 . The system of claim 1 , wherein for at least one member selected from the group consist of the reaction mass and the optical element, a the member is surface-processed so that at least one of the following holds:
its mass is adapted to the first elastic element; its mass is adapted the second elastic element; its stiffness is adapted to the first elastic element; and its stiffness is adapted to the second elastic element.

14 . The system of claim 13 , wherein the surface-processed surface is an etched surface or a lasered surface.

15 . The system of claim 1 , wherein the optical element comprises at least one member selected from the group consisting of a mirror and a lens.

16 . The system of claim 1 , wherein the system is configured so that, when the actuator actuates the optical element relative to the carrying element, a force on the carrying element resulting from the actuation is zero

17 . An apparatus, comprising:
a first system comprising the system of claim 1 , wherein the apparatus comprises a lithography apparatus.

18 . The apparatus of claim 17 , further comprising a second system selected from the group of a lithography beam shaping system, a lithography illumination system, a lithography projection system, and a lithography photomask, wherein the second system comprises the first system.

19 . A system, comprising:
an optical element; a carrying element; an actuator configured to actuate the optical element relative to the carrying element; a first elastic e

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Kwan Yim-Bun Patrick
• Groothuijsen Tim

Classifications

• G03F7/7015 Primary

  Details of optical elements · CPC title

• F16F7/104

  the inertia member being resiliently mounted {(F16F7/1022 takes precedence)} · CPC title

• F16F15/022 Primary

  using dampers and springs in combination · CPC title

• G02B7/005

  Motorised alignment · CPC title

• G03F7/70825

  Mounting of individual elements, e.g. mounts, holders or supports (workpiece or mask holders G03F7/707) · CPC title