Lithography optics adjustment and monitoring

Patent metadata

Field	Value
Publication number	US-10345714-B2
Application number	US-201715619900-A
Country	US
Kind code	B2
Filing date	Jun 12, 2017
Priority date	Jul 12, 2016
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

Methods and apparatus for processing an image of a beam generated by an optical system to extract information indicative of an extent of damage to optical elements in the optical system. Also disclosed is a beam image and analysis tool capable of acquiring an image of a beam at any one of a number of locations.

First claim

The invention claimed is:

1. A photolithographic apparatus comprising:
a laser source for generating an output laser beam to be used for patterning features on a wafer; and
a metrology module arranged to receive at least a portion of the output laser beam after the output laser beam has traversed an output optical path of the laser source, the output optical path including a plurality of optical components, the metrology module including a screen element arranged to receive the at least a portion of the output laser beam and generating an image of the portion of the output laser beam when struck by the portion of the output laser beam and a camera arranged to view the screen element for acquiring the image, the metrology module also including an optical module arranged optically between the plurality of optical components and the screen element, the optical module including at least one movable optical element for altering the image on the screen element, the output optical path including a first optical element and a second optical element and wherein the optical module is arranged optically after the first and second optical elements and before the screen element, and wherein the at least one movable optical element has a first position in which the image is of a cross section of the beam immediately after the beam has traversed the first optical element and a second position in which the image is of a cross section of the beam after the beam has traversed both the first optical element and the second optical element.

2. The photolithographic apparatus as claimed in claim 1 wherein the metrology module is arranged to receive at least a portion of the laser beam after the laser beam has traversed substantially all of the optical components in the optical path.

3. The photolithographic apparatus as claimed in claim 2 wherein the metrology module is part of a combined autoshutter and metrology module.

4. The photolithographic apparatus as claimed in claim 2 wherein the optical module comprises a variable focus lens.

5. The photolithographic apparatus as claimed in claim 2 wherein the optical module comprises a varifocal lens.

6. The photolithographic apparatus as claimed in claim 2 wherein the optical module comprises a parfocal lens.

7. The photolithographic apparatus as claimed in claim 2 further comprising a driver and wherein the at least one movable optical element is mechanically coupled to the driver.

8. The photolithographic apparatus as claimed in claim 7 wherein the driver comprises a stepper motor.

9. The photolithographic apparatus as claimed in claim 7 wherein the driver comprises a piezoelectric translator.

10. The photolithographic apparatus as claimed in claim 7 wherein the at least one movable optical element is mechanically coupled to a driver mounted on a track.

11. The photolithographic apparatus as claimed in claim 10 wherein the driver comprises a stepper motor.

12. The photolithographic apparatus as claimed in claim 7 further comprising a controller electrically connected to the driver wherein the controller generates a control signal to control the driver.

13. The photolithographic apparatus as claimed in claim 1 wherein the metrology module is part of a combined autoshutter and metrology module.

14. The photolithographic apparatus as claimed in claim 1 wherein the optical module comprises a variable focus lens.

15. The photolithographic apparatus as claimed in claim 1 wherein the optical module comprises a varifocal lens.

16. The photolithographic apparatus as claimed in claim 1 wherein the optical module comprises a parfocal lens.

17. The photolithographic apparatus as claimed in claim 1 further comprising a driver and wherein the at least one movable optical element is mechanically coupled to the driver.

18. The photolithographic apparatus as claimed in claim 17 wherein the driver comprises a stepper motor.

19. The photolithographic apparatus as claimed in claim 17 wherein the driver comprises a piezoelectric translator.

20. The photolithographic apparatus as claimed in claim 17 wherein the at least one movable optical element is mechanically coupled to a driver mounted on a track.

21. The photolithographic apparatus as claimed in claim 20 wherein the driver comprises a stepper motor.

22. The photolithographic apparatus as claimed in claim 17 further comprising a controller electrically connected to the driver wherein the controller generates a control signal to control the driver.

23. The photolithographic apparatus as claimed in claim 1 wherein the optical module comprises a plurality of fixed focus lenses positionable one at a time in the optical path.

24. The photolithographic apparatus as claimed in claim 23 wherein the beam path includes a first optical element and a second optical element and wherein the optical module is arranged optically after the first and second optical elements and before the screen element, and wherein the at least one movable optical element has a first position in a first fixed lens is positioned in the beam path to obtain an image of a cross section of the beam immediately after the beam has traversed the first output optical element and a second position in which a second fixed lens is positioned in the beam path the image is of a cross section of the beam after it has traversed the first and second output optical elements.

25. A photolithographic apparatus comprising:
a laser source for generating a laser beam; and
a metrology module arranged to receive at least a portion of the laser beam after the laser beam has traversed an optical path of the laser source, the optical path including a plurality of optical components, the metrology module including a screen element arranged to receive the at least a portion of the laser beam and generating an image of the portion of the laser beam when struck by the portion of the laser beam and a camera arranged to view the screen element for acquiring the image, the metrology module also including an optical module arranged optically between the plurality of optical components and the screen element, the optical module including a variable focus lens for altering the image on the screen element.

26. A photolithographic apparatus comprising:
a laser source for generating a laser beam; and
a metrology module arranged to receive at least a portion of the laser beam after the laser beam has traversed an optical path of the laser source, the optical path including a plurality of optical components, the metrology module including a screen element arranged to receive the at least a portion of the laser beam and generating an image of the portion of the laser beam when struck by the portion of the laser beam and a camera arranged to view the screen element for acquiring the image, the metrology module also including an optical module arranged optically between the plurality of optical components and the screen element, the optical module including a varifocal lens for altering the image on the screen element.

27. A photolithographic apparatus comprising:
a laser source for generating a laser beam; and
a metrology module arranged to receive at least a portion of the laser beam after the laser beam has traversed an optical path of the laser source, the optical path including a first optical element and a second optical element, the metrology module including a screen eleme

Assignees

• Cymer LLC

Inventors

• Bibby Jr Thomas Frederick Allen
• Zurita Omar
• Subramanian Abhishek
• Duffey Thomas Patrick

Classifications

• H10P76/2042

  using lasers · CPC title

• G01J1/429

  applied to measurement of ultraviolet light (using counting tubes G01T) · CPC title

• G03F7/70591

  Testing optical components · CPC title

• G01J2001/4247

  for testing lamps or other light sources · CPC title

• G01J1/4257 Primary

  applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam (monitoring arrangements for lasers in general H01S3/0014) · CPC title