EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

• US 20200133137A1
• Filed: 12/31/2019
• Published: 04/30/2020
• Est. Priority Date: 08/29/2017
• Status: Active Grant

• Current Assignee: Gigaphoton, Inc. (Komatsu)
• Original Assignee: Gigaphoton, Inc. (Komatsu)
• Inventors: SUGISAWA, Katsuhiko
• Granted Patent: US 11,003,085 B2
• Time in Patent Office: Days
• CPC Class Codes: G03F 7/20 Exposure; Apparatus therefor photographic printing apparatus for making copies G03B27/00
• CPC Class Codes: G03F 7/70033 by plasma extreme ultraviolet [EUV] sources
• CPC Class Codes: G03F 7/70175 Lamphouse reflector arrangements or collector mirrors, i.e. collecting light from solid angle upstream of the light source
• CPC Class Codes: G03F 7/7085 Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load
• CPC Class Codes: G03F 7/70908 Hygiene, e.g. preventing apparatus pollution, mitigating effect of pollution or removing pollutants from apparatus
• CPC Class Codes: H05G 2/005 containing a metal as principal radiation generating component
• CPC Class Codes: H05G 2/008 involving a beam of energy, e.g. laser or electron beam in the process of exciting the plasma

Abstract

In an extreme ultraviolet light generating apparatus, the film thickness of debris adhering to a surface of a component can be measured easily without need of large-scale removal of the component disposed in the chamber. The extreme ultraviolet light generating apparatus includes a chamber in which a droplet made of a target material is irradiated with a laser beam and extreme ultraviolet light is generated, an EUV light collector mirror that is an optical element disposed in the chamber, and a measurement device movable along a surface of the EUV light collector mirror and configured to measure the film thickness of the target material adhering to the surface.

Claims

1. An extreme ultraviolet light generating apparatus comprising:

a chamber in which a target material is irradiated with a laser beam and extreme ultraviolet light is generated;

an optical element disposed in the chamber; and

a measurement device movable along a surface of the optical element and configured to measure a film thickness of the target material adhering to the surface of the optical element.

2. The extreme ultraviolet light generating apparatus according to claim 1, wherein

the optical element is an extreme ultraviolet light collector mirror configured to collect the extreme ultraviolet light.

3. The extreme ultraviolet light generating apparatus according to claim 1, wherein

the optical element is a laser beam condensing mirror configured to condense a laser beam traveling toward the target material.

4. The extreme ultraviolet light generating apparatus according to claim 1, wherein

the optical element is a damper mirror configured to reflect a laser beam that, after traveling toward the target material, has passed through a plasma generating region without being radiated to the target material.

5. The extreme ultraviolet light generating apparatus according to claim 1, wherein

the measurement device includes a fluorescent X-ray unit configured to measure the film thickness by fluorescent X-ray analysis.

6. The extreme ultraviolet light generating apparatus according to claim 1, wherein

the measurement device includes a polyarticular robot configured to move a unit that measures the film thickness along the surface of the optical element.

7. The extreme ultraviolet light generating apparatus according to claim 1, further comprising

a notification unit configured to notify that replacement of the optical element is required when a number of points where the film thickness of the target material adhering to the surface exceeds a predetermined thickness is equal to or more than a first number.

8. The extreme ultraviolet light generating apparatus according to claim 1, further comprising

a control unit configured to lower power of the extreme ultraviolet light to be generated when a number of points where the film thickness of the target material adhering to the surface exceeds a predetermined thickness is equal to or more than a second number.

9. The extreme ultraviolet light generating apparatus according to claim 8, wherein

the control unit lowers the power by decreasing a repetition frequency of a pulse laser beam to be radiated to the target material.

10. The extreme ultraviolet light generating apparatus according to claim 1, further comprising

a notification unit configured to notify that replacement of the optical element is required when a number of points where the film thickness of the target material adhering to the surface exceeds a predetermined thickness is equal to or more than a first number;

and

a control unit configured to lower power of the extreme ultraviolet light to be generated when the number of the points is equal to or more than a second number smaller than the first number.

11. An extreme ultraviolet light generating apparatus comprising:

a chamber in which a target material is irradiated with a laser beam and extreme ultraviolet light is generated;

a heat shield disposed in the chamber; and

a measurement device movable along a surface of the heat shield and configured to measure a film thickness of the target material adhering to the surface of the heat shield.

12. The extreme ultraviolet light generating apparatus according to claim 11, wherein

the measurement device includes a fluorescent X-ray unit configured to measure the film thickness by fluorescent X-ray analysis.

13. The extreme ultraviolet light generating apparatus according to claim 11, wherein

the measurement device includes a polyarticular robot configured to move a unit that measures the film thickness along the surface of the heat shield.

14. The extreme ultraviolet light generating apparatus according to claim 11, further comprising

a notification unit configured to notify that replacement of the heat shield is required when a number of points where the film thickness of the target material adhering to the surface exceeds a predetermined thickness is equal to or more than a first number.

15. The extreme ultraviolet light generating apparatus according to claim 11, further comprising

a control unit configured to lower power of the extreme ultraviolet light to be generated when a number of points where the film thickness of the target material adhering to the surface exceeds a predetermined thickness is equal to or more than a second number.

16. The extreme ultraviolet light generating apparatus according to claim 15, wherein

the control unit lowers the power by decreasing a repetition frequency of a pulse laser beam to be radiated to the target material.

17. The extreme ultraviolet light generating apparatus according to claim 11, further comprising

a notification unit configured to notify that replacement of the heat shield is required when a number of points where the film thickness of the target material adhering to the surface exceeds a predetermined thickness is equal to or more than a first number;

and

a control unit configured to lower power of the extreme ultraviolet light to be generated when the number of the points is equal to or more than a second number smaller than the first number.

18. An extreme ultraviolet light generating apparatus comprising:

a chamber in which a target material is irradiated with a laser beam and extreme ultraviolet light is generated;

an exhaust path through which exhaust from inside of the chamber flows; and

a measurement device movable along an inner surface of the exhaust path and configured to measure a film thickness of the target material adhering to the inner surface of the exhaust path.

19. The extreme ultraviolet light generating apparatus according to claim 18, wherein

the measurement device includes a fluorescent X-ray unit configured to measure the film thickness by fluorescent X-ray analysis.

20. The extreme ultraviolet light generating apparatus according to claim 18, wherein

the measurement device includes a polyarticular robot configured to move a unit that measures the film thickness along the inner surface of the exhaust path.