Integrated Circuit Manufacturing Methods with Patterning Device Position Determination

• US 20090061361A1
• Filed: 10/31/2008
• Published: 03/05/2009
• 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 Franciscus, Engels, Marc Johannes Martinus, Bartray, Petrus Rutgerus, Van Der Wijst, Marc Wilhelmus Maria, Luttikhuis, Bernardus Antonius Johannes, Franken, Dominicus Jacobus Petrus Adrianus, Box, Wilhelmus Josephus
• Granted Patent: US 7,804,584 B2
• Time in Patent Office: Days
• US Class Current: 430/311
• 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

Methods of manufacturing an integrated circuit by a lithographic apparatus are disclosed. The methods include patterning a radiation beam with a patterning device, projecting the patterned beam onto a substrate using a projection system, and determining the position of the patterning device. In one example, the patterning device'"'"'s position relative to the projection system is determined by measuring the position of the patterning device'"'"'s support structure. In another example, the position can be determined by measuring a position of the patterning device relative to its support and by measuring a position of the support. In another example, a Z-position of the patterning device is determined by directing at least one beam of radiation onto a part of the patterning device located outside a pattern area. This can be done by directing a pair of laser beams from sensors on the projection system to reflecting strips on the patterning device.

Claims

1. 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.

2. 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.

3. A method according to claim 2, wherein the beam of radiation is generated by an EUV radiation source.

4. A method according to claim 2, wherein said measuring the position of the patterning device comprises using a measuring unit that comprises a 6 degrees of freedom interferometer measurement system.

5. A method according to claim 2, 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.

6. A method according to claim 2, wherein said patterning the beam of radiation comprises irradiating the patterning device along a scanning direction.

7. A method according to claim 6, wherein said determining the position of the patterning device relative to the projection system 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.

8. A method according to claim 7, wherein the measurement points are located on the support.

9. A method according to claim 8, wherein at least two measurement points are located on the patterning device outside a pattern area of the patterning device.

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

patterning a first beam of radiation with a patterning device;

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

determining a Z-position of the patterning device using at least one second beam of radiation directed onto a part of the patterning device, the part being located outside a pattern area of the patterning device.

11. A method according to claim 10, wherein the at least one second beam is directed in the Z-direction to the patterning device.

12. A method according to claim 10, wherein the Z-position is determined by measuring normally with respect to the patterning device, the Z-position being part of a spatial position of the patterning device relative to the projection system.

13. A method according to claim 12, wherein sensors mounted on the projection system direct the at least one second beam onto the part of the patterning device that is located outside the pattern area of the patterning device.

14. A method according to claim 13, wherein the sensors direct pairs of laser beams to reflecting strips on the patterning device.