Lithographic apparatus and device menufacturing method

• US 20060060799A1
• Filed: 11/01/2005
• Published: 03/23/2006
• Est. Priority Date: 07/11/2002
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Loopstra, Erik Roelof, Van Der Wijst, Marc Wilhelmus Maria, Van Schothorst, Gerard, Franken, Dominicus Jacobus Petrus Adrianus, Dries, Johan Juliana, Bartray, Pertrus Rutgerus, Renkens, Michael Jozefa Mathijs
• Granted Patent: US 7,554,105 B2
• Time in Patent Office: Days
• US Class Current: 250/492.220
• CPC Class Codes: G03F 7/70833 Mounting of optical systems, e.g. mounting of illumination system, projection system or stage systems on base-plate or ground
• CPC Class Codes: G03F 7/709 Vibration, e.g. vibration detection, compensation, suppression or isolation

Abstract

A lithographic apparatus includes a projection system mounted on a reference frame, which in turn is mounted on a base which supports the apparatus. Vibrations and displacement errors in the base are filtered through two sets of isolation mounts operatively between the base and reference frame and between the reference frame and a projection frame of the projection system and therefore disturbance of the projection system is reduced.

Claims

1. A lithographic projection apparatus, comprising:

a radiation system configured to provide a beam of radiation;

a support configured to support a patterning device, the patterning device configured to pattern the beam according to a desired pattern;

a substrate table configured to hold a substrate;

a projection system configured to project the patterned beam onto a target portion of the substrate;

a base to which the support and the substrate table are mounted; and

a reference frame compliantly mounted to the base, wherein the projection system comprises at least one optical element mounted on a projection frame that is compliantly mounted to the reference frame.

2. A lithographic projection apparatus according to claim 1, wherein an eigenfrequency of the projection frame compliantly mounted to the reference frame is between about 10 and 30 Hz.

3. A lithographic projection apparatus according to claim 1, wherein an eigenfrequency of the reference frame compliantly mounted to the base is about 0.5 Hz.

4. A lithographic projection apparatus according to claim 1, wherein the projection system is compliantly mounted to the reference frame by at least three compliant mounts.

5. A lithographic projection apparatus according to claim 1, wherein the projection system is mounted to the reference frame on nodal axes of a dominant mode of bending vibration of the reference frame or a torsional vibration of the reference frame.

6. A lithographic projection apparatus according to claim 1, further comprising;

a second projection frame mounted to the reference frame;

sensors mounted to the second projection frame configured to monitor positions of optical elements mounted to the projection frame.

7. A lithographic projection apparatus according to claim 6, wherein the second projection frame is compliantly mounted to the reference frame.

8. A lithographic projection apparatus according to claim 1, wherein the projection system is compliantly mounted to the reference frame by at least one compliant mount that is one of an air-mount, a spring and a magnetic support.

9. A lithographic projection apparatus according to claim 1, wherein motion of the projection system relative to the reference frame is damped.

10. A lithographic projection apparatus according to claim 9, wherein the motion of the projection system relative to the reference frame is actively damped by piezoelectric actuators or Lorentz-force actuators.

11. A device manufacturing method, comprising:

providing a substrate that is at least partially covered by a layer of radiation-sensitive material;

projecting a patterned beam of radiation onto a target portion of the layer of radiation-sensitive material using a projection system;

supporting a reference frame, a support configured to support a patterning device, and a substrate table configured to hold the substrate, on a base, wherein the reference frame is compliantly mounted to the base and the projection system is mounted to the reference frame; and

compliantly mounting the projection system to the reference frame while projecting the patterned beam of radiation onto the target portion.

12. A method according to claim 11, wherein the projection system comprises at least one optical element mounted on a projection frame that is compliantly mounted to the reference frame and an eigenfrequency of the projection frame compliantly mounted to the reference frame is between about 10 and 30 Hz.

13. A method according to claim 11, wherein an eigenfrequency of the reference frame compliantly mounted to the base is about 0.5 Hz.

14. A method according to claim 11, wherein the projection system is compliantly mounted to the reference frame by at least three compliant mounts.

15. A method according to claim 11, wherein the projection system is compliantly mounted to the reference frame on nodal axes of a dominant mode of bending vibration of the reference frame or a torsional vibration of the reference frame.

16. A method according to claim 11, further comprising:

mounting a second projection frame to the reference frame; and

mounting sensors to the second projection frame, wherein the sensors are configured to monitor positions of optical elements mounted to the projection frame.

17. A method according to claim 16, wherein mounting the second projection frame to the reference frame comprises compliantly mounting the second projection frame to the reference frame.

18. A method according to claim 11, wherein the projection system is compliantly mounted to the reference frame by at least one compliant mount that is one of an air-mount, a spring and a magnetic support.

19. A method according to claim 11, wherein motion of the projection system relative to the reference frame is damped.

20. A method according to claim 19, wherein the motion of the projection system relative to the reference frame is actively damped by piezoelectric actuators or Lorentz-force actuators.

21. A lithographic projection apparatus, comprising:

a radiation system configured to provide a beam of radiation;

a support configured to support a patterning device, the patterning device configured to pattern the beam according to a desired pattern;

a substrate table configured to hold a substrate;

a projection system configured to project the patterned beam onto a target portion of the substrate;

a base to which the support and the substrate table are mounted;

a reference frame mounted to the base, wherein the projection system comprises at least one optical element mounted on a projection frame that is mounted to the reference frame;

at least one first isolation mount operatively between the reference frame and the base to inhibit vibrations or movements of a predetermined type from being transmitted from the base to the reference frame; and

at least one second isolation mount operatively between the reference frame and the projection frame to inhibit vibrations or movements of a predetermined type from being transmitted from the reference frame to the projection frame.