CN-116918196-B - Gas laser device and method for manufacturing electronic device

Abstract

The gas laser device includes a laser oscillator including a pair of discharge electrodes disposed opposite to each other and generating light by a laser gas by applying a voltage, an amplifier including an amplifying section and an amplifying-side resonator, a beam splitter that reflects a part of the light from the laser-side resonator, a photosensor that detects the light reflected by the beam splitter, and a processor that controls the voltage according to an output of the photosensor. The amplification side resonator includes a rear mirror and an amplification side output coupling mirror, and the laser side resonator includes a grating and a laser side output coupling mirror. In the event that the voltage is below a threshold of the voltage, the processor maintains the voltage at a fixed value above the threshold.

Inventors

• ISHIDA KEISUKE

Assignees

• 极光先进雷射株式会社

Dates

Publication Date

20260512

Application Date

20210325

Claims (17)

1. 1. A gas laser device, comprising: a laser oscillator including a pair of discharge electrodes disposed opposite to each other and generating light by a laser gas by applying a voltage, and a laser side resonator resonating the light; An amplifier including an amplifying section that amplifies the light transmitted through the laser side resonator and an amplifying side resonator that resonates the light amplified by the amplifying section; A beam splitter that reflects a part of the light from the laser side resonator; A light sensor detecting the light reflected by the beam splitter, and A processor controlling the voltage in accordance with the output of the light sensor, The amplification side resonator includes: A rear mirror that transmits a part of the light from the laser side resonator, reflects another part of the light from the laser side resonator toward the laser side resonator, transmits a part of the light amplified by the amplifying section toward the laser side resonator, and reflects another part of the light amplified by the amplifying section, and An amplifying side output coupling mirror that reflects a part of the light amplified by the amplifying section and transmits another part of the light amplified by the amplifying section, The laser side resonator includes: a grating for reflecting the light generated by the laser gas, and A laser side output coupling mirror that reflects a part of the light generated by the laser gas, transmits another part of the light generated by the laser gas toward the beam splitter, reflects a part of the light from the rear mirror toward the beam splitter, In the event that the voltage is below a threshold of the voltage, the processor maintains the voltage at a fixed value above the threshold.
2. 2. The gas laser apparatus according to claim 1, wherein, The fixed value is a value greater than the threshold value.
3. 3. The gas laser apparatus according to claim 1, wherein, The fixed value is the same value as the threshold value.
4. 4. The gas laser apparatus according to claim 1, wherein, In the event that the moving average of the voltage is below the threshold, the processor maintains the voltage at the fixed value.
5. 5. The gas laser apparatus according to claim 1, wherein, The gas laser device further includes a display unit that notifies the start of maintaining the voltage at the fixed value.
6. 6. The gas laser apparatus according to claim 5, wherein, A signal representing the number of pulses of the light is input from the light sensor to the processor, The processor stops the application of the voltage when the cumulative value of the pulse number after the start of the notification is greater than a threshold value of the cumulative value, that is, a cumulative threshold value.
7. 7. The gas laser apparatus according to claim 6, wherein, When the integrated value is greater than the integrated threshold value, the processor outputs a signal indicating an error to an exposure apparatus to which the light from the amplifying-side output coupling mirror is incident.
8. 8. A gas laser device, comprising: a laser oscillator including a pair of discharge electrodes disposed opposite to each other and generating light by a laser gas by applying a voltage, and a laser side resonator resonating the light; An amplifier including an amplifying section that amplifies the light transmitted through the laser side resonator and an amplifying side resonator that resonates the light amplified by the amplifying section; A beam splitter that reflects a part of the light from the laser side resonator; A light sensor detecting the light reflected by the beam splitter, and A processor controlling the voltage in accordance with the output of the light sensor, The amplification side resonator includes: A rear mirror that transmits a part of the light from the laser side resonator, reflects another part of the light from the laser side resonator toward the laser side resonator, transmits a part of the light amplified by the amplifying section toward the laser side resonator, and reflects another part of the light amplified by the amplifying section, and An amplifying side output coupling mirror that reflects a part of the light amplified by the amplifying section and transmits another part of the light amplified by the amplifying section, The laser side resonator includes: a grating for reflecting the light generated by the laser gas, and A laser side output coupling mirror that reflects a part of the light generated by the laser gas, transmits another part of the light generated by the laser gas toward the beam splitter, reflects a part of the light from the rear mirror toward the beam splitter, In the case where the voltage is lower than a threshold value of the voltage, the processor increases the voltage to a prescribed value greater than the threshold value.
9. 9. The gas laser apparatus according to claim 8, wherein, The processor increases the voltage to the prescribed value in the case where the moving average of the voltage is lower than the threshold value.
10. 10. The gas laser apparatus according to claim 8, wherein, The gas laser device further includes a display unit that notifies the start of the voltage increase to the predetermined value.
11. 11. The gas laser apparatus according to claim 8, wherein, In the case where the voltage raised to the prescribed value is lower than the threshold value, the processor raises the voltage to the prescribed value again.
12. 12. The gas laser apparatus according to claim 11, wherein, The processor increases a target value of the pulse energy of the light every time the voltage is lower than the threshold value, and stops the application of the voltage in a case where the target value is greater than a target threshold value, which is a threshold value of the target value.
13. 13. The gas laser apparatus according to claim 12, wherein, When the target value is greater than the target threshold value, the processor outputs a signal indicating an error to an exposure apparatus to which the light from the amplification-side output coupling mirror is incident.
14. 14. The gas laser apparatus according to claim 8, wherein, The processor stops the application of the voltage when the moving average of the voltage after the increase to the predetermined value is lower than the threshold value.
15. 15. The gas laser apparatus according to claim 14, wherein, When the moving average is lower than the threshold value, the processor outputs a signal indicating an error to an exposure apparatus to which the light from the amplification-side output coupling mirror is incident.
16. 16. A method of manufacturing an electronic device, comprising the steps of: The laser light is generated by a gas laser device, The laser light is output to an exposure device, Exposing the laser light on a photosensitive substrate in the exposure apparatus to manufacture an electronic device, The gas laser device includes: a laser oscillator including a pair of discharge electrodes disposed opposite to each other and generating light by a laser gas by applying a voltage, and a laser side resonator resonating the light; An amplifier including an amplifying section that amplifies the light transmitted through the laser side resonator and an amplifying side resonator that resonates the light amplified by the amplifying section; A beam splitter that reflects a part of the light from the laser side resonator; A light sensor detecting the light reflected by the beam splitter, and A processor controlling the voltage in accordance with the output of the light sensor, The amplification side resonator includes: A rear mirror that transmits a part of the light from the laser side resonator, reflects another part of the light from the laser side resonator toward the laser side resonator, transmits a part of the light amplified by the amplifying section toward the laser side resonator, and reflects another part of the light amplified by the amplifying section, and An amplifying side output coupling mirror that reflects a part of the light amplified by the amplifying section and transmits another part of the light amplified by the amplifying section, The laser side resonator includes: a grating for reflecting the light generated by the laser gas, and A laser side output coupling mirror that reflects a part of the light generated by the laser gas, transmits another part of the light generated by the laser gas toward the beam splitter, reflects a part of the light from the rear mirror toward the beam splitter, In the event that the voltage is below a threshold of the voltage, the processor maintains the voltage at a fixed value above the threshold.
17. 17. A method of manufacturing an electronic device, comprising the steps of: The laser light is generated by a gas laser device, The laser light is output to an exposure device, Exposing the laser light on a photosensitive substrate in the exposure apparatus to manufacture an electronic device, The gas laser device includes: a laser oscillator including a pair of discharge electrodes disposed opposite to each other and generating light by a laser gas by applying a voltage, and a laser side resonator resonating the light; An amplifier including an amplifying section that amplifies the light transmitted through the laser side resonator and an amplifying side resonator that resonates the light amplified by the amplifying section; A beam splitter that reflects a part of the light from the laser side resonator; A light sensor detecting the light reflected by the beam splitter, and A processor controlling the voltage in accordance with the output of the light sensor, The amplification side resonator includes: A rear mirror that transmits a part of the light from the laser side resonator, reflects another part of the light from the laser side resonator toward the laser side resonator, transmits a part of the light amplified by the amplifying section toward the laser side resonator, and reflects another part of the light amplified by the amplifying section, and An amplifying side output coupling mirror that reflects a part of the light amplified by the amplifying section and transmits another part of the light amplified by the amplifying section, The laser side resonator includes: a grating for reflecting the light generated by the laser gas, and A laser side output coupling mirror that reflects a part of the light generated by the laser gas, transmits another part of the light generated by the laser gas toward the beam splitter, reflects a part of the light from the rear mirror toward the beam splitter, In the case where the voltage is lower than a threshold value of the voltage, the processor increases the voltage to a prescribed value greater than the threshold value.

Description

Gas laser device and method for manufacturing electronic device Technical Field The present disclosure relates to a gas laser apparatus and a method of manufacturing an electronic device. Background In recent years, in semiconductor exposure apparatuses, with miniaturization and high integration of semiconductor integrated circuits, improvement in resolution has been demanded. Therefore, the reduction in wavelength of light emitted from the exposure light source has been advanced. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs laser light having a wavelength of about 248.0nm and an ArF excimer laser device that outputs laser light having a wavelength of about 193.4nm are used. The natural oscillation light of the KrF excimer laser device and the ArF excimer laser device has a wide spectral line width of about 350pm to 400pm. Therefore, when the projection lens is formed of a material that transmits ultraviolet rays such as KrF and ArF laser light, chromatic aberration may occur. As a result, the resolution may be lowered. Therefore, it is necessary to narrow the line width of the laser light output from the gas laser device to such an extent that chromatic aberration can be disregarded. Therefore, in a laser resonator of a gas laser device, there is a case where a narrow-band module (Line Narrowing Module:lnm) including narrow-band elements (etalons, gratings, etc.) is provided in order to narrow the line width. Hereinafter, a gas laser device whose line width is narrowed is referred to as a narrowed gas laser device. Prior art literature Patent literature Patent document 1 Japanese patent application No. 4364757 Patent document 2 Japanese patent No. 5513653 Patent document 3 specification of U.S. Pat. No. 7382816 Disclosure of Invention The gas laser device according to one aspect of the present disclosure may include a laser oscillator including a pair of discharge electrodes and a laser side resonator, the pair of discharge electrodes being disposed opposite to each other and generating light by applying a voltage to the laser side resonator, the laser side resonator resonating light, an amplifier including an amplifying section amplifying light transmitted through the laser side resonator and an amplifying side resonator resonating light amplified by the amplifying section, a beam splitter reflecting a part of light from the laser side resonator, a photosensor detecting light reflected by the beam splitter, and a processor controlling a voltage according to an output of the photosensor, the amplifying side resonator including a rear mirror transmitting a part of light from the laser side resonator, reflecting another part of light from the laser side resonator toward the laser side resonator, transmitting a part of light amplified by the amplifying section toward the laser side resonator, reflecting another part of light amplified by the amplifying section, and an amplifying side output coupling mirror reflecting a part of light amplified by the amplifying section, reflecting a part of light amplified by the amplifying section toward the laser side resonator, and generating a fixed value by a threshold value by a beam splitter transmitting another part of light from the laser side resonator, and generating a fixed value by a voltage when the laser gas is transmitted by the other part of the laser side resonator. The gas laser device according to one aspect of the present disclosure may include a laser oscillator including a pair of discharge electrodes and a laser side resonator, the pair of discharge electrodes being disposed opposite to each other and generating light by applying a voltage to the laser side resonator, the laser side resonator resonating light, an amplifier including an amplifying section amplifying light transmitted through the laser side resonator and an amplifying side resonator resonating light amplified by the amplifying section, a beam splitter reflecting a part of light from the laser side resonator, a photosensor detecting light reflected by the beam splitter, and a processor controlling a voltage according to an output of the photosensor, the amplifying side resonator including a rear mirror transmitting a part of light from the laser side resonator, reflecting another part of light from the laser side resonator toward the laser side resonator, transmitting a part of light amplified by the amplifying section toward the laser side resonator, reflecting another part of light amplified by the amplifying section, and an amplifying side output coupling mirror reflecting a part of light amplified by the amplifying section, reflecting a part of light amplified by the amplifying section toward the laser side resonator, and generating a threshold voltage by the laser gas when the voltage is raised by the voltage of the beam splitter. The method for manufacturing an electronic device according to one embodiment of the present disclosure may incl