Extreme ultraviolet light generation system and electronic device manufacturing method

Patent metadata

Field	Value
Publication number	US-11778721-B2
Application number	US-202117457342-A
Country	US
Kind code	B2
Filing date	Dec 2, 2021
Priority date	Jan 20, 2021
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

An extreme ultraviolet light generation system includes a target supply unit configured to supply a target substance to a first predetermined region, a laser system configured to output pulse laser light to be radiated to the target substance in the first predetermined region, a first sensor configured to detect an arrival timing at which the target substance has reached a second predetermined region between the target supply unit and the first predetermined region, an optical adjuster arranged on an optical path of the pulse laser light between the laser system and the first predetermined region, and a processor configured to control transmittance of the pulse laser light through the optical adjuster based on the arrival timing.

First claim

What is claimed is:

1. An extreme ultraviolet light generation system, comprising:
a target supply unit configured to supply a target substance to a first predetermined region;
a laser system configured to output pulse laser light to be radiated to the target substance in the first predetermined region;
a first sensor configured to detect an arrival timing at which the target substance has reached a second predetermined region between the target supply unit and the first predetermined region;
an optical adjuster arranged on an optical path of the pulse laser light between the laser system and the first predetermined region; and
a processor configured to control transmittance of the pulse laser light through the optical adjuster based on the arrival timing.

2. The extreme ultraviolet light generation system according to claim 1 ,
wherein, when an interval of the arrival timing detected by the first sensor is a first time interval, the processor controls the transmittance so that the optical adjuster transmits the pulse laser light at first transmittance, and when the interval of the arrival timing detected by the first sensor is a second time interval shorter than the first time interval, the processor controls the transmittance so that the optical adjuster transmits the pulse laser light at second transmittance higher than the first transmittance.

3. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor controls the transmittance so that second variation in pulse energy of the pulse laser light transmitted through the optical adjuster is smaller than first variation in pulse energy of the pulse laser light incident on the optical adjuster.

4. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor controls the transmittance by controlling an application voltage of the optical adjuster.

5. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor controls the transmittance based on the arrival timing within a period after the target substance reaches the second predetermined region until the target substance reaches the first predetermined region.

6. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor outputs a trigger timing signal to the laser system based on the arrival timing.

7. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor outputs different timing signals respectively to the laser system and the optical adjuster based on the arrival timing.

8. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor controls the transmittance based on a relationship between a laser oscillation interval of the laser system and a pulse energy of the pulse laser light.

9. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor controls the transmittance based on both of a relationship between a laser oscillation interval of the laser system and a pulse energy of the pulse laser light and a relationship between an application voltage of the optical adjuster and the transmittance.

10. The extreme ultraviolet light generation system according to claim 1 ,
wherein the processor controls the transmittance based on both of a change rate of a pulse energy of the pulse laser light when a laser oscillation interval of the laser system varies and a change rate of the transmittance when an application voltage of the optical adjuster varies.

11. The extreme ultraviolet light generation system according to claim 1 ,
wherein the target supply unit supplies the target substance in a droplet form to the first predetermined region.

12. The extreme ultraviolet light generation system according to claim 1 ,
wherein the laser system includes a YAG laser device.

13. The extreme ultraviolet light generation system according to claim 1 ,
wherein the laser system includes an excitation light source which outputs continuous oscillation laser light to excite a laser medium of the laser system.

14. The extreme ultraviolet light generation system according to claim 1 ,
wherein the optical adjuster includes any one of an acoustic optical element, an electric optical element, and an attenuator.

15. The extreme ultraviolet light generation system according to claim 1 ,
further comprising a second sensor configured to detect a pulse energy of extreme ultraviolet light generated by irradiating the target substance with the pulse laser light,
wherein the processor controls the transmittance based on both of the arrival timing and the pulse energy.

16. The extreme ultraviolet light generation system according to claim 15 ,
wherein the processor performs feedback control on the transmittance based on the pulse energy.

17. The extreme ultraviolet light generation system according to claim 1 ,
further comprising a second sensor configured to detect a pulse energy of extreme ultraviolet light generated by irradiating the target substance with the pulse laser light,
wherein the pulse laser light includes prepulse laser light radiated to the target substance and main pulse laser light radiated to the target substance to which the prepulse laser light has been radiated,
the laser system includes a prepulse laser device which outputs the prepulse laser light and a main pulse laser device which outputs the main pulse laser light,
the optical adjuster includes a first optical adjuster arranged on an optical path of the prepulse laser light between the prepulse laser device and the first predetermined region, and a second optical adjuster arranged on an optical path of the main pulse laser light between the main pulse laser device and the first predetermined region, and
the processor controls transmittance of the prepulse laser light through the first optical adjuster based on the arrival timing and controls transmittance of the main pulse laser light through the second optical adjuster based on both of the arrival timing and the pulse energy.

18. The extreme ultraviolet light generation system according to claim 17 ,
wherein the processor controls the transmittance of the main pulse laser light so that the pulse energy has a greater influence on the transmittance of the main pulse laser light than the transmittance of the prepulse laser light.

19. An electronic device manufacturing method, comprising:
generating extreme ultraviolet light in an extreme ultraviolet light generation system;
emitting the extreme ultraviolet light to an exposure apparatus; and
exposing a photosensitive substrate to the extreme ultraviolet light in the exposure apparatus to manufacture an electronic device,
the extreme ultraviolet light generation system including:
a target supply unit configured to supply a target substance to a first predetermined region;
a laser system configured to output pulse laser light to be radiated to the target substance in the first predetermined region;
a first sensor configured to detect an arrival timing at which the target substance has reached a second predetermined region between the target supply unit and the first predetermined region;
an optical adjuster arranged on an optical path of the pulse laser light between the laser system and the first predetermined region; and
a processor configured to control transmittance of the pulse laser light through the optical adjuster based on the arrival timing.

20. An electronic device manufactur

Assignees

• Gigaphoton Inc

Inventors

• Nishimura Yuichi
• Yabu Takayuki
• Nakarai Hiroaki

Classifications

• H05G2/0027

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

• H05G2/0086

  Optical arrangements for conveying the laser beam to the plasma generation location · CPC title

• H05G2/0084 Primary

  Control of the laser beam · CPC title

• H05G2/008 Primary

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

• H01S3/11

  Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping · CPC title