System for generating extreme ultra violet light

Patent metadata

Field	Value
Publication number	US-2016341601-A1
Application number	US-201615224894-A
Country	US
Kind code	A1
Filing date	Aug 1, 2016
Priority date	Nov 16, 2011
Publication date	Nov 24, 2016
Grant date	—

Abstract

A system for generating extreme ultraviolet light may include a chamber, a target supply device configured to supply a target material into the chamber, a laser apparatus configured to output a laser beam to irradiate the target material, a wavefront adjuster configured to adjust a wavefront of the laser beam, an imaging optical system configured to focus the laser beam reflected by the target material, an image detector configured to capture an image of the laser beam focused by the imaging optical system, and a controller configured to control the wavefront adjuster based on the captured image.

First claim

1 . An extreme ultraviolet (EUV) light generation system configured to irradiate a target material with a laser beam to generate EUV light and to output the EUV light to an exposure apparatus, the EUV light generation system comprising:
a laser apparatus configured to output the laser beam to irradiate the target material; a focusing optical system configured to focus the laser beam outputted from the laser apparatus; a target generator configured to output the target material; an EUV light monitor configured to detect a generation position at which the EUV light is generated; and a controller configured to control generation of the EUV light, wherein: when the controller receives an EUV light generation position specification signal specifying a predetermined position as the generation position, the controller adjusts the focusing optical system such that a focus position of the laser beam coincides with the predetermined position and adjusts a position of the target generator to allow the target material to pass through the predetermined position; and upon receiving the generation position detected by the EUV light monitor, the controller determines whether or not the received generation position falls within a permissible range, and, when the received generation position does not fall within the permissible range, the controller adjusts at least one of the position of the target generator and the focusing optical system such that the received generation position falls within the permissible range.

2 . The EUV light generation system according to claim 1 , wherein the generation position specification signal is sent from the exposure apparatus.

3 . The EUV light generation system according to claim 1 , wherein the controller sends a laser output signal to the laser apparatus to cause the laser apparatus to output the laser beam.

4 . The EUV light generation system according to claim 3 , wherein the controller sends the laser output signal before receiving the generation position detected by the EUV light monitor.

5 . The EUV light generation system according to claim 1 , wherein the controller sends a target output signal to the target generator to cause the target generator to output the target material.

6 . The EUV light generation system according to claim 5 , wherein the controller sends the target output signal before adjusting the position of the target generator.

7 . The EUV light generation system according to claim 1 , wherein the controller sends an exposure pause signal to the exposure apparatus to notify the exposure apparatus of a pause of exposure.

8 . The EUV light generation system according to claim 7 , wherein the controller sends the exposure pause signal after receiving the generation position specification signal.

9 . The EUV light generation system according to claim 1 , wherein the controller sends an exposure permission signal to the exposure apparatus to notify the exposure apparatus of permission of exposure.

10 . The EUV light generation system according to claim 9 , wherein the controller sends the exposure permission signal after the received generation position falls within the permissible range.

11 . The EUV light generation system according to claim 1 , wherein:
the controller sends an exposure pause signal to notify the exposure apparatus of a pause of exposure after receiving the generation position specification signal; the controller sends a target output signal to the target generator to cause the target generator to output the target material before adjusting the position of the target generator; the controller sends a laser output signal to the laser apparatus to cause the laser apparatus to output the laser beam before receiving the generation position detected by the EUV light monitor; and the controller sends an exposure permission signal to the exposure apparatus to notify the exposure apparatus of permission of exposure after the received generation position falls within the permissible range.

12 . The EUV light generation system according to claim 1 , further comprising a detector configured to detect a backpropagating beam which is the laser beam reflected by the target material,
wherein the controller controls the focus position of the laser beam based on a detection result by the detector.

13 . The EUV light generation system according to claim 12 , wherein the detector includes an image sensor or a wavefront sensor.

14 . The EUV light generation system according to claim 12 , wherein the controller controls the focus position of the laser beam based on the detection result by the detector, before receiving the generation position detected by the EUV light monitor.

15 . The EUV light generation system according to claim 12 , wherein:
the detector includes a wavefront sensor configured to detect a wavefront of the backpropagating beam; and the controller calculates whether or not the focus position of the laser beam is offset from the target material along a direction of a beam axis of the laser beam by using a detection result by the wavefront sensor, and controls the focus position of the laser beam based on a calculation result.

16 . The EUV light generation system according to claim 12 , further comprising a first laser beam control unit configured to control a focus position of a first laser beam that diffuses the target material, wherein:
the laser apparatus includes a first laser apparatus configured to output the first laser beam; and the controller controls the first laser beam control unit.

17 . The EUV light generation system according to claim 16 , wherein the first laser beam control unit includes a wavefront adjuster.

18 . The EUV light generation system according to claim 16 , further comprising:
an attenuator configured to attenuate the first laser beam; and a moving part configured to insert or remove the attenuator into or from a beam path of the first laser beam, wherein the controller controls drive of the moving part to control a period of time for which the attenuator is inserted or removed.

19 . The EUV light generation system according to claim 18 , wherein the controller controls the period of time for which the attenuator is inserted or removed such that the attenuator is inserted or removed for a period of time for which the EUV light to be outputted to the exposure apparatus is not generated.

20 . The EUV light generation system according to claim 18 , wherein:
the inserting or removing the attenuator includes moving the attenuator onto the beam path of the first laser beam and moving the attenuator on the beam path of the first laser beam out of the beam path; and the controller controls the period of time for which the attenuator is inserted or removed such that the attenuator is moved onto the beam path after the controller receives the generation position specification signal, and the attenuator on the beam path is out of the beam path before the laser beam for generating the EUV light to be outputted to the exposure apparatus is outputted.

Assignees

• Gigaphoton Inc

Inventors

• Moriya Masato
• Wakabayashi Osamu

Classifications

• H05G2/0086

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

• G03F7/70258

  Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system · CPC title

• G01J1/44

  Electric circuits {(for command of an exposure part G03B7/02)} · CPC title

• G01J1/429

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

• G01J9/00

  Measuring optical phase difference (devices or arrangements for controlling the phase of light beams G02F1/01); Determining degree of coherence; Measuring optical wavelength (spectrometry G01J3/00) · CPC title