Lithographic apparatus and integrated circuit manufacturing method

• US 20050024611A1
• Filed: 06/25/2004
• Published: 02/03/2005
• Est. Priority Date: 06/27/2003
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Van Der Pasch, Engelbertus Antonius Fransiscus, Van Der Wijst, Marc Wilhelmus Maria, Luttikhuis, Bernardus Antonius Johannes, Franken, Dominicus Jacobus Petrus Adrianus, Engels, Marc Johannes Martinus, Box, Wilhelmus Josephus, Bartray, Pertrus Rutgerus
• Granted Patent: US 7,471,373 B2
• Time in Patent Office: Days
• US Class Current: 355/53
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position

Abstract

A lithographic apparatus is disclosed. The apparatus includes a radiation system for supplying a beam of radiation, and a support structure for supporting a patterning device. The patterning device serves to pattern the beam of radiation according to a desired pattern. The apparatus also includes a projection system for projecting the patterned beam of radiation onto a target portion of a substrate, and an assembly for determining a spatial position of the patterning device relative to the projection system. The assembly includes a measuring unit that has a plurality of sensors that are mounted on the projection system.

Claims

1. A lithographic projection apparatus comprising:

a radiation system for supplying a beam of radiation;

a support structure for supporting a patterning device, the patterning device serving to pattern the beam of radiation according to a desired pattern;

a projection system for projecting the patterned beam of radiation onto a target portion of a substrate; and

an assembly for determining a spatial position of said patterning device relative to said projection system, said assembly comprising a measuring unit having a plurality of sensors mounted on the projection system.

2. A lithographic projection apparatus according to claim 1, wherein the radiation system comprises an EUV radiation source.

3. A lithographic projection apparatus according to claim 1, wherein said measuring unit comprises a 6 degrees of freedom interferometer measurement system.

4. A lithographic projection apparatus according to claim 1, wherein at least one of said sensors uses a laser beam on a reflective part of said patterning device outside a pattern area of said patterning device.

5. A lithographic projection apparatus according to claim 1, wherein the patterning device in the lithographic projection apparatus is irradiated along a scanning direction, and the spatial position of said patterning device relative to said projection system is determined by the use of at least three measurement points in a first plane, the first plane being at an angle to the scanning direction, at least two measurement points on a first line being not in the first plane, and at least one point both being not in the first plane and being not on the first line.

6. A lithographic projection apparatus according to claim 5, wherein said measurement points are located on said support structure.

7. A lithographic projection apparatus according to claim 5, wherein at least two measurement points are located on the patterning device outside a pattern area of said patterning device.

8. A method of manufacturing an integrated circuit by a lithographic apparatus, the method comprising:

patterning a beam of radiation with a patterning device that is supported by a support structure;

projecting the patterned beam of radiation onto a substrate, by use of a projection system;

determining the position of the patterning device relative to the support structure at least once; and

determining, during operation of the lithographic apparatus, the position of the patterning device relative to the projection system, from a measurement of the position of the support structure.

9. A method of manufacturing an integrated circuit with a lithographic apparatus, the method comprising:

patterning a beam of radiation with a patterning device that is supported by a support;

imaging the patterned beam of radiation onto a target portion of a substrate with a projection system;

measuring a position of the patterning device relative to the support;

measuring a position of the support; and

determining, during operation of the lithographic apparatus, a position of the patterning device relative to the projection system.

10. A method according to claim 9, wherein the beam of radiation is generated by a EUV radiation source.

11. A method according to claim 9, wherein said measuring the position of the patterning device comprises using a measuring unit that comprises a 6 degrees of freedom interferometer measurement system.

12. A method according to claim 9, wherein said measuring the position of the patterning device comprises using sensors that are mounted on the projection system, wherein at least one of the sensors uses a laser beam on a reflective part of the patterning device outside a pattern area of the patterning device.

13. A method according to claim 9, wherein said patterning the beam of radiation comprises irradiating the patterning device along a scanning direction.

14. A method according to claim 13, wherein said determining the position of the patterning device relative to the projection device comprises using at least three measurement points in a first plane, the first plane being at an angle to the scanning direction, at least two measurement points being on a first line that is not in the first plane, and at least one point both not being in the first plane and not being on the first line.

15. A method according to claim 14, wherein the measurement points are located on the support.

16. A method according to claim 15, wherein at least two measurement points are located on the patterning device outside a pattern area of the patterning device.