Extreme ultraviolet light generation apparatus, target control method, and electronic device manufacturing method

Patent metadata

Field	Value
Publication number	US-11229112-B2
Application number	US-202117227912-A
Country	US
Kind code	B2
Filing date	Apr 12, 2021
Priority date	May 11, 2020
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

An extreme ultraviolet light generation apparatus may include a target supply unit configured to output a target; an actuator configured to change a trajectory of the target; an illumination device configured to illuminate the target; a first trajectory sensor configured to detect the trajectory in a first direction; a second trajectory sensor configured to detect the trajectory in a second direction; and a processor configured, when the trajectory of the target is detected by the first trajectory sensor but is not detected by the second trajectory sensor, to perform a first search and determine whether or not to repeat the first search based on a signal intensity of the first trajectory sensor, the first search including changing the trajectory of the target into a third direction by controlling the actuator, and then determining whether or not the second trajectory sensor is capable of detecting the trajectory of the target.

First claim

What is claimed is:

1. An extreme ultraviolet light generation apparatus configured to generate extreme ultraviolet light by irradiating a target with laser light, comprising:
a target supply unit configured to output the target;
an actuator configured to change a trajectory of the target;
an illumination device configured to illuminate the target;
a first trajectory sensor configured to detect the trajectory of the target in a first direction;
a second trajectory sensor configured to detect the trajectory of the target in a second direction being different from the first direction; and
a processor configured, when the trajectory of the target is detected by the first trajectory sensor but is not detected by the second trajectory sensor, to perform a first search and determine whether or not to repeat the first search based on a signal intensity of the first trajectory sensor, the first search including changing the trajectory of the target into a third direction being different from the second direction by controlling the actuator, and then determining whether or not the second trajectory sensor is capable of detecting the trajectory of the target.

2. The extreme ultraviolet light generation apparatus according to claim 1 ,
wherein the processor alternately performs the first search and a second search, determines whether or not to repeat the first search based on the signal intensity of the first trajectory sensor obtained in the first search, and determines whether or not to repeat the second search based on a signal intensity of the first trajectory sensor obtained in the second search, the second search including changing the trajectory of the target into a fourth direction being different from the third direction by controlling the actuator, and then determining whether or not the second trajectory sensor is capable of detecting the trajectory of the target.

3. The extreme ultraviolet light generation apparatus according to claim 2 ,
wherein the fourth direction is opposite to the third direction.

4. The extreme ultraviolet light generation apparatus according to claim 2 ,
wherein the processor continuously performs the second search when the processor determines to repeat the second search after determining not to repeat the first search.

5. The extreme ultraviolet light generation apparatus according to claim 2 ,
wherein the processor continuously performs the first search when the processor determines to repeat the first search after determining not to repeat the second search.

6. The extreme ultraviolet light generation apparatus according to claim 1 ,
wherein the processor continuously performs the first search when the processor determines to repeat the first search.

7. The extreme ultraviolet light generation apparatus according to claim 6 ,
wherein, when the processor determines not to repeat the first search, the processor performs a second search and determines whether or not to repeat the second search based on the signal intensity of the first trajectory sensor, the second search including changing the trajectory of the target into a fourth direction being different from the third direction by controlling the actuator, and then determining whether or not the second trajectory sensor is capable of detecting the trajectory of the target.

8. The extreme ultraviolet light generation apparatus according to claim 1 ,
wherein, when the trajectory of the target is detected by both the first trajectory sensor and the second trajectory sensor, the processor controls the actuator so that the trajectory of the target detected by the first trajectory sensor and the trajectory of the target detected by the second trajectory sensor approach corresponding target positions respectively.

9. The extreme ultraviolet light generation apparatus according to claim 1 ,
wherein the processor determines not to repeat the first search when the number of the first searches exceeds an upper limit.

10. The extreme ultraviolet light generation apparatus according to claim 1 ,
wherein the processor determines not to repeat the first search when the trajectory of the target is not detected by the first trajectory sensor.

11. The extreme ultraviolet light generation apparatus according to claim 1 ,
wherein the processor determines not to repeat the first search when the signal intensity is less than a threshold.

12. The extreme ultraviolet light generation apparatus according to claim 11 ,
wherein the processor sets a predetermined value as the threshold.

13. The extreme ultraviolet light generation apparatus according to claim 11 ,
wherein the processor determines the threshold based on a reference value, the reference value being the signal intensity of the first trajectory sensor before the first search is performed.

14. The extreme ultraviolet light generation apparatus according to claim 13 ,
wherein the processor sets, as the threshold, a value obtained by decreasing the reference value by a predetermined ratio.

15. The extreme ultraviolet light generation apparatus according to claim 11 ,
wherein the actuator is configured to change the trajectory of the target by moving the target supply unit, and
when repeating the first search, the processor controls the actuator so that the target supply unit is moved to a reference position, newly obtains a signal intensity of the first trajectory sensor, and determines the threshold based on a reference value being the newly obtained signal intensity.

16. The extreme ultraviolet light generation apparatus according to claim 15 ,
wherein the processor sets, as the reference position, a position of the target supply unit before the first search is firstly performed.

17. The extreme ultraviolet light generation apparatus according to claim 15 ,
wherein the processor sets, as the reference value, an average value of signal intensities of a plurality of pulses included in a signal output from the first trajectory sensor.

18. The extreme ultraviolet light generation apparatus according to claim 1 ,
wherein the processor determines not to repeat the first search when an average value of signal intensities of a plurality of pulses included in a signal output from the first trajectory sensor is less than a threshold.

19. A target control method with an extreme ultraviolet light generation apparatus configured to generate extreme ultraviolet light by irradiating a target with laser light, the method comprising:
determining whether or not a trajectory of the target is detected by a first trajectory sensor and a second trajectory sensor; and
when the trajectory of the target is detected by the first trajectory sensor but is not detected by the second trajectory sensor, performing a first search and determining whether or not to repeat the first search based on a signal intensity of the first trajectory sensor,
the first search including changing the trajectory of the target into a third direction being different from a second direction by controlling an actuator, and then determining whether or not the second trajectory sensor is capable of detecting the trajectory of the target, and
the extreme ultraviolet light generation apparatus including:
a target supply unit configured to output the target;
the actuator configured to change the trajectory of the target;
an illumination device configured to illuminate the target;
the first trajectory sensor configured to detect the trajectory of the target in a first direction; and
the second trajectory sensor configured to d

Assignees

• Gigaphoton Inc

Inventors

• Abe Toru

Classifications

• H05G2/0027 Primary

  Arrangements for controlling the supply; Arrangements for measurements · CPC title

• G03F7/70033

  by plasma extreme ultraviolet [EUV] sources · CPC title

• G03F7/70525

  Controlling normal operating mode, e.g. matching different apparatus, remote control or prediction of failure · CPC title

• H05G2/008 Primary

  involving an energy-carrying beam in the process of plasma generation · CPC title