Narrowbanding device and manufacturing method of electronic device

Abstract

The narrowbanding device has: a first prism and a second prism, which are arranged at different positions in the wavelength dispersion direction of any one of the first prism and the second prism; a third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, allows the first part of the light beam to enter the first prism, and allows the second part of the light beam to enter the second prism; a grating, which is arranged to straddle the optical path of the first part after passing through the first prism and the optical path of the second part after passing through the second prism; a first actuator, which adjusts the incident angle of the first part incident on the grating; a second actuator, which adjusts the incident angle of the second part incident on the grating; and a third actuator, which adjusts the energy ratio between the first part and the second part.

Description

Technical Field

[0001] The present disclosure relates to a narrowing device and a method for manufacturing an electronic device. Background Art

[0002] In recent years, in semiconductor exposure apparatuses, with the miniaturization and high integration of semiconductor integrated circuits, an improvement in resolution has been required. Therefore, the shortening of the wavelength of light emitted from an exposure light source has been developed. For example, as a gas laser device for exposure, a KrF excimer laser device that uses a laser with an output wavelength of approximately 248 nm and an ArF excimer laser device that uses a laser with an output wavelength of approximately 193 nm are used.

[0003] The spectral line widths of the spontaneous oscillation lights of KrF excimer laser devices and ArF excimer laser devices are relatively wide, approximately 350 to 400 pm. Therefore, when a projection lens is formed of a material that transmits ultraviolet rays such as KrF and ArF lasers, chromatic aberration sometimes occurs. As a result, the resolution may decrease. Therefore, it is necessary to narrow the spectral line width of the laser output from the gas laser device to a level where chromatic aberration can be ignored. Therefore, in the laser resonator of the gas laser device, in order to narrow the spectral line width, a narrowing module (Line Narrowing Module: LNM) including a narrowing element (etalon, grating, etc.) is sometimes provided. Hereinafter, a gas laser device whose spectral line width has been narrowed will be referred to as a narrowed gas laser device.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 02-276283

[0007] Patent Document 2: Japanese Patent Laid-Open No. 2006-269628 Summary of the Invention

[0008] A narrowing device according to one aspect of the present disclosure includes: a first prism and a second prism, which are arranged at positions different in the wavelength dispersion direction of any one of the first prism and the second prism; a third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and causes a first part of the light beam to enter the first prism and a second part of the light beam to enter the second prism; a grating, which is arranged to straddle the optical path of the first part after passing through the first prism and the optical path of the second part after passing through the second prism; a first actuator, which adjusts the incident angle of the first part incident on the grating; a second actuator, which adjusts the incident angle of the second part incident on the grating; and a third actuator, which adjusts the energy ratio between the first part and the second part.

[0009] The narrowbanding device according to another aspect of the present disclosure includes: a first prism and a second prism, which are arranged at different positions in the wavelength dispersion direction of any one of the first prism and the second prism; a third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and makes the first part of the light beam incident on the first prism and the second part of the light beam incident on the second prism; a first grating, which is arranged on the optical path of the first part after passing through the first prism; a second grating, which is arranged on the optical path of the second part after passing through the second prism; a first actuator, which adjusts the incident angle of the first part incident on the first grating; a second actuator, which adjusts the incident angle of the second part incident on the second grating; and a third actuator, which adjusts the energy ratio between the first part and the second part.

[0010] The method for manufacturing an electronic device according to one aspect of the present disclosure includes the following steps: generating pulsed laser light by a laser device, outputting the pulsed laser light to an exposure device, and exposing the pulsed laser light on a photosensitive substrate in the exposure device to manufacture an electronic device. The laser device includes a laser cavity and an optical resonator including a narrowbanding device. The narrowbanding device includes: a first prism and a second prism, which are arranged at different positions in the wavelength dispersion direction of any one of the first prism and the second prism; a third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and makes the first part of the light beam incident on the first prism and the second part of the light beam incident on the second prism; a grating, which is arranged to straddle the optical path of the first part after passing through the first prism and the optical path of the second part after passing through the second prism; a first actuator, which adjusts the incident angle of the first part incident on the grating; a second actuator, which adjusts the incident angle of the second part incident on the grating; and a third actuator, which adjusts the energy ratio between the first part and the second part.

[0011] Another aspect of the manufacturing method of the electronic device according to the present disclosure includes the following steps: generating pulsed laser by a laser device, outputting the pulsed laser to an exposure device, and exposing the pulsed laser on a photosensitive substrate in the exposure device to manufacture the electronic device. The laser device includes a laser cavity and an optical resonator including a narrowing device. The narrowing device has: a first prism and a second prism, which are arranged at different positions in the wavelength dispersion direction of any one of the first prism and the second prism; a third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and makes the first part of the light beam incident on the first prism and the second part of the light beam incident on the second prism; a first grating, which is arranged on the optical path of the first part after passing through the first prism; a second grating, which is arranged on the optical path of the second part after passing through the second prism; a first actuator, which adjusts the incident angle of the first part incident on the first grating; a second actuator, which adjusts the incident angle of the second part incident on the second grating; and a third actuator, which adjusts the energy ratio between the first part and the second part. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Hereinafter, several embodiments of the present disclosure will be described as simple examples with reference to the drawings.

[0013] Figure 1 The structure of the exposure system in the comparative example is schematically shown.

[0014] Figure 2 The structure of the exposure system in the comparative example is schematically shown.

[0015] Figure 3A and Figure 3B The structure of the narrowing device in the comparative example is schematically shown.

[0016] Figure 4A and Figure 4B The structure of the narrowing device in the first embodiment is schematically shown.

[0017] Figure 5A and Figure 5B The structure of the narrowing device in the first modification is schematically shown.

[0018] Figure 6A and Figure 6B The structure of the narrowing device in the second modification is schematically shown.

[0019] Figure 7A and Figure 7B The structure of the narrowing device in the third modification is schematically shown.

[0020] Figure 8A and Figure 8B The structure of the narrowing device in the fourth modification is schematically shown.

[0021] Figure 9A and Figure 9B Schematically shows the structure of the narrowbanding device in the fifth modification example.

[0022] Figure 10A and Figure 10B Schematically shows the structure of the narrowbanding device in the second embodiment.

[0023] Figure 11A and Figure 11B Schematically shows the structure of the narrowbanding device in the sixth modification example.

[0024] Figure 12A and Figure 12B Schematically shows the structure of the narrowbanding device in the seventh modification example. Detailed Description of the Invention

[0025] Contents

[0026] 1. Comparative Example

[0027] 1.1 Exposure System

[0028] 1.1.1 Structure of Exposure Device 100

[0029] 1.1.2 Operation

[0030] 1.2 Narrowband Gas Laser Device

[0031] 1.2.1 Structure

[0032] 1.2.1.1 Master Oscillator MO

[0033] 1.2.1.2 Laser Control Processor 30

[0034] 1.2.1.3 Gas Adjustment Device GA

[0035] 1.2.2 Operation

[0036] 1.2.2.1 Laser Control Processor 30

[0037] 1.2.2.2 Master Oscillator MO

[0038] 1.2.2.3 Gas Adjustment Device GA

[0039] 1.3 Narrowbanding Device

[0040] 1.3.1 Structure

[0041] 1.3.1.1 Prisms 41 to 44

[0042] 1.3.1.2 Grating 50

[0043] 1.3.2 Operation

[0044] 1.3.3 Problems of the Comparative Example

[0045] 2. Narrowbanding Device Capable of Adjusting Energy Ratio of Multiple Wavelength Components 2.1 First Embodiment

[0046] 2.1.1 Structure

[0047] 2.1.2 Operation

[0048] 2.1.3 Other Structural Examples

[0049] 2.1.4 Function

[0050] 2.2 First Variation

[0051] 2.2.1 Structure and Operation

[0052] 2.2.2 Function

[0053] 2.3 Second Variation

[0054] 2.3.1 Structure

[0055] 2.3.2 Operation

[0056] 2.3.3 Other Structural Examples

[0057] 2.3.4 Function

[0058] 2.4 Third Variation

[0059] 2.4.1 Structure

[0060] 2.4.2 Operation

[0061] 2.4.3 Other Structural Examples

[0062] 2.4.4 Function

[0063] 2.5 Fourth Variation

[0064] 2.5.1 Structure

[0065] 2.5.2 Operation

[0066] 2.5.3 Other Structural Examples

[0067] 2.5.4 Function

[0068] 2.6 Fifth Variation

[0069] 2.6.1 Structure

[0070] 2.6.2 Operation

[0071] 2.6.3 Other Structural Examples

[0072] 2.6.4 Function

[0073] 3. Narrowbanding Device with Multiple Gratings

[0074] 3.1 Second Embodiment

[0075] 3.1.1 Structure

[0076] 3.1.2 Operation

[0077] 3.1.3 Other Structural Examples

[0078] 3.1.4 Function

[0079] 3.2 Sixth Variant Example

[0080] 3.2.1 Structure

[0081] 3.2.2 Operation

[0082] 3.2.3 Other Structural Examples

[0083] 3.2.4 Function

[0084] 3.3 Seventh Variant Example

[0085] 3.3.1 Structure

[0086] 3.3.2 Operation

[0087] 3.3.3 Other Structural Examples

[0088] 3.3.4 Function

[0089] 4. Others

[0090] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below show several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and operations described in each embodiment are not necessarily all essential to the structures and operations of the present disclosure. In addition, the same reference numerals are assigned to the same structural elements and repeated descriptions are omitted.

[0091] 1. Comparative Example

[0092] 1.1 Exposure System

[0093] Figure 1 and Figure 2 Schematically shows the structure of the exposure system in the comparative example. The comparative example of the present disclosure is a manner known only to the applicant, not a publicly known example admitted by the applicant himself.

[0094] The exposure system includes a narrowbanding gas laser device 1 and an exposure device 100. In Figure 1 a simplified view of the narrowbanding gas laser device 1 is shown. In Figure 2The exposure apparatus 100 is schematically shown below.

[0095] The narrow-band gas laser device 1 includes a laser control processor 30. The narrow-band gas laser device 1 is configured to output pulsed laser light toward the exposure apparatus 100.

[0096] 1.1.1 Structure of the exposure apparatus 100

[0097] As Figure 1 shown, the exposure apparatus 100 includes an illumination optical system 101, a projection optical system 102, and an exposure control processor 110.

[0098] The illumination optical system 101 illuminates a mask pattern of an unillustrated mask disposed on the mask stage RT with pulsed laser light incident from the narrow-band gas laser device 1.

[0099] The projection optical system 102 reduces and projects the pulsed laser light that has passed through the mask and forms an image on an unillustrated workpiece disposed on the workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a resist film.

[0100] The exposure control processor 110 is a processing device that includes a memory 112 storing a control program and a CPU (central processing unit) 111 that executes the control program. The exposure control processor 110 is specially configured or programmed to execute various processes included in the present disclosure. The exposure control processor 110 overall controls the exposure apparatus 100 and transmits and receives various data and various signals to and from the laser control processor 30.

[0101] 1.1.2 Operation

[0102] The exposure control processor 110 sends data on the target value of the wavelength, data on the target value of the pulse energy, and a trigger signal to the laser control processor 30. The laser control processor 30 controls the narrow-band gas laser device 1 in accordance with this data and signal.

[0103] The exposure control processor 110 moves the mask stage RT and the workpiece stage WT synchronously in opposite directions parallel to each other. Thereby, the workpiece is exposed with pulsed laser light reflecting the mask pattern.

[0104] The mask pattern is transferred onto the semiconductor wafer through such an exposure process. Then, electronic devices can be manufactured through multiple processes.

[0105] 1.2 Narrow-band gas laser device

[0106] 1.2.1 Structure

[0107] AsFigure 2 As shown, in addition to the laser control processor 30, the narrowband gas laser device 1 further includes a master oscillator MO and a gas adjustment device GA.

[0108] 1.2.1.1 Master Oscillator MO

[0109] The master oscillator MO includes a laser cavity 10, a charger 12, a pulse power module (PPM) 13, a narrowbanding device 14, an output coupling mirror 15, an optical detector 17, and a shutter 18. The narrowbanding device 14 and the output coupling mirror 15 form an optical resonator.

[0110] The laser cavity 10 is arranged on the optical path of the optical resonator. Windows 10a and 10b are provided in the laser cavity 10.

[0111] The laser cavity 10 has a pair of electrodes 11a and 11b inside, and further houses a laser gas as a laser medium. The laser medium is, for example, F2, ArF, KrF, XeCl, or XeF.

[0112] A pressure sensor 16 is installed in the laser cavity 10.

[0113] The charger 12 holds the electric energy for supplying to the pulse power module 13. The pulse power module 13 includes a switch 13a.

[0114] The narrowbanding device 14 includes wavelength selection elements such as prisms 41 and 42, and gratings 51 and 52 described later.

[0115] The output coupling mirror 15 is composed of a partial reflector.

[0116] The optical detector 17 includes a beam splitter 17a and a sensor unit 17b. The beam splitter 17a is arranged on the optical path of the pulsed laser output from the output coupling mirror 15. The beam splitter 17a is configured to transmit a part of the pulsed laser with a high transmittance, and reflect the other part of the pulsed laser and make it incident on the sensor unit 17b. The sensor unit 17b is configured to include a spectroscopic sensor and can output measurement data of the wavelength. Further, the sensor unit 17b is configured to include an energy sensor and can output measurement data of the pulse energy.

[0117] The shutter 18 is arranged on the optical path of the pulsed laser that has passed through the beam splitter 17a. When the shutter 18 is closed, the pulsed laser that has passed through the beam splitter 17a is blocked and does not enter the exposure device 100. When the shutter 18 is opened, the pulsed laser that has passed through the beam splitter 17a is not blocked and enters the exposure device 100.

[0118] 1.2.1.2 Laser Control Processor 30

[0119] The laser control processor 30 is a processing device, including a memory 32 storing a control program and a CPU 31 executing the control program. The laser control processor 30 is specifically configured or programmed to execute various processes included in the present disclosure.

[0120] 1.2.1.3 Gas adjustment device GA

[0121] The gas adjustment device GA includes a gas supply device 33, a gas exhaust device 34, and a gas control processor 35.

[0122] The gas supply device 33 includes a valve (not shown), and the valve is provided in the first pipe between the laser cavity 10 and a gas cylinder (not shown).

[0123] The gas exhaust device 34 includes a valve (not shown), a pump, and a decontamination device provided in the second pipe connected to the laser cavity 10.

[0124] The gas control processor 35 is a processing device, including a memory 37 storing a control program and a CPU 36 executing the control program. The gas control processor 35 is specifically configured or programmed to execute various processes included in the present disclosure.

[0125] 1.2.2 Operations

[0126] 1.2.2.1 Laser control processor 30

[0127] The laser control processor 30 obtains data of the target value of the wavelength from the exposure control processor 110. The laser control processor 30 sends an initial setting signal to the narrowing device 14 according to the target value of the wavelength. After the output of the pulsed laser starts, the laser control processor 30 receives the measured data of the wavelength from the optical detector 17, and sends a feedback control signal to the narrowing device 14 according to the target value of the wavelength and the measured data of the wavelength.

[0128] The laser control processor 30 obtains data of the target value of the pulse energy from the exposure control processor 110. The laser control processor 30 sends an initial setting signal of the charging voltage to the charger 12 according to the target value of the pulse energy. After the output of the pulsed laser starts, the laser control processor 30 receives the measured data of the pulse energy from the optical detector 17, and sends a feedback control signal of the charging voltage to the charger 12 according to the target value of the pulse energy and the measured data of the pulse energy.

[0129] The laser control processor 30 receives a trigger signal from the exposure control processor 110. The laser control processor 30 sends an oscillation trigger signal based on the trigger signal to the switch 13a of the pulse power module 13.

[0130] The laser control processor 30 sends a gas control signal to the gas control processor 35. In addition, the laser control processor 30 receives the measurement data of the air pressure P from the pressure sensor 16 and sends the measurement data of the air pressure P to the gas control processor 35.

[0131] 1.2.2.2 Master Oscillator MO

[0132] The switch 13a becomes on after receiving the oscillation trigger signal from the laser control processor 30. After the switch 13a becomes on, the pulse power module 13 generates a pulsed high voltage according to the electric energy stored in the charger 12. The pulse power module 13 applies this high voltage to the electrodes 11a and 11b.

[0133] After applying the high voltage to the electrodes 11a and 11b, a discharge is caused between the electrodes 11a and 11b. By the energy of this discharge, the laser gas in the laser cavity 10 is excited and transitions to a higher energy level. Then, when the excited laser gas transitions to a lower energy level, it emits light with a wavelength corresponding to the energy level difference.

[0134] The light generated in the laser cavity 10 exits to the outside of the laser cavity 10 through the windows 10a and 10b. The light exiting from the window 10a enters the narrowbanding device 14 as a light beam. The light near the desired wavelength among the light incident on the narrowbanding device 14 is reflected back to the laser cavity 10 by the narrowbanding device 14.

[0135] The output coupling mirror 15 allows a part of the light exiting from the window 10b to pass through and be output, and reflects the other part back to the laser cavity 10.

[0136] In this way, the light exiting from the laser cavity 10 reciprocates between the narrowbanding device 14 and the output coupling mirror 15. This light is amplified every time it passes through the discharge space between the pair of electrodes 11a and 11b. In this way, the laser oscillation is performed and the narrowbanded light is output as pulsed laser light from the output coupling mirror 15.

[0137] The pulsed laser light output from the narrowbanded gas laser device 1 is incident on the exposure device 100.

[0138] 1.2.2.3 Gas Adjustment Device GA

[0139] The gas control processor 35 controls the gas supply device 33 and the gas exhaust device 34 according to the gas control signal and the measurement data of the air pressure P received from the laser control processor 30 so that the air pressure P inside the laser cavity 10 becomes a desired value.

[0140] For example, when increasing the internal gas pressure P of the laser cavity 10, the gas control processor 35 controls to open the valve included in the gas supply device 33 to supply laser gas to the inside of the laser cavity 10. Further, for example, when decreasing the internal gas pressure P of the laser cavity 10, the gas control processor 35 controls to open the valve included in the gas exhaust device 34 to discharge a part of the laser gas inside the laser cavity 10.

[0141] 1.3 Narrowbanding device

[0142] 1.3.1 Structure

[0143] Figure 3A and Figure 3B The structure of the narrowbanding device 14 in the comparative example is schematically shown. In each figure, the V-axis, H-axis, and Z-axis perpendicular to each other are shown. Figure 3A The narrowbanding device 14 viewed in the -V direction is shown, Figure 3B The narrowbanding device 14 viewed in the -H direction is shown. The -V direction and +V direction coincide with the directions facing the electrodes 11a and 11b (see Figure 2 ). The -Z direction coincides with the traveling direction of the light beam emitted from the window 10a. The +Z direction coincides with the traveling direction of the pulsed laser emitted from the window 10b and output via the output coupling mirror 15.

[0144] The narrowbanding device 14 includes prisms 41 to 44 and a grating 50.

[0145] 1.3.1.1 Prisms 41 to 44

[0146] The prism 44 is disposed on the optical path of the light beam emitted from the window 10a. The prism 44 is supported by a holder 441.

[0147] The prism 43 is disposed on the optical path of the light beam after passing through the prism 44. The prism 43 corresponds to the third prism in the present disclosure. The prism 43 is supported by a holder 431.

[0148] The prisms 41 and 42 are disposed at positions different from each other in the wavelength dispersion direction DD of any one of the prisms 41 and 42 in the optical path of the light beam after passing through the prism 43. The prism 41 corresponds to the first prism in the present disclosure, and the prism 42 corresponds to the second prism in the present disclosure. The prism 41 is supported by a holder 411, and the prism 42 is supported by a holder 421. The positions of the prisms 41 and 42 are set such that the light beam after passing through the prism 43 is incident on the prisms 41 and 42 so as to straddle the prisms 41 and 42. The wavelength dispersion direction DD of the prism refers to the direction in which the refraction angle of the light at the surface of the prism is dispersed according to the wavelength. In Figure 3A and Figure 3B the example shown, the wavelength dispersion directions DD of the prisms 41 and 42 are the same.

[0149] The prisms 41 to 44 are made of a material such as calcium fluoride or synthetic quartz that has a high transmittance for the selected wavelength of the narrowbanding device 14.

[0150] The prisms 41 to 44 are arranged such that the surfaces of the prisms 41 to 44 where the light beam enters and exits are all parallel to the V axis. The prism 41 can be rotated around an axis parallel to the V axis by a rotating stage 412, and the prism 42 can be rotated around an axis parallel to the V axis by a rotating stage 422.

[0151] 1.3.1.2 Grating 50

[0152] The grating 50 is arranged to straddle the optical paths of both the first part B1 of the light beam that has passed through the prism 41 and the second part B2 of the light beam that has passed through the prism 42. The direction of the grooves of the grating 50 is the same as the V-axis direction. The grating 50 is supported by a holder 501.

[0153] 1.3.2 Operation

[0154] The light beam exiting from the window 10a passes through the prisms 44 and 43 respectively, changes its traveling direction within a plane parallel to the plane perpendicular to the V axis, i.e., the HZ plane, and expands the beam width within a plane parallel to the HZ plane. As an example, the traveling direction of the light beam that passes through both the prisms 44 and 43 and is directed towards the prisms 41 and 42 is substantially the same as the -Z direction.

[0155] The first part B1 of the light beam that has passed through the prism 43 is incident on the prism 41, and the second part B2 is incident on the prism 42. The incident angles of the light beams incident on the prisms 41 and 42 depend on the respective postures of the prisms 41 and 42. The light beams incident on the prisms 41 and 42 change their traveling directions according to the respective postures of the prisms 41 and 42 and are emitted towards the grating 50.

[0156] The light incident on the grating 50 from the prisms 41 and 42 is reflected by the multiple grooves of the grating 50 and diffracted in a direction corresponding to the wavelength of the light. Thus, the light reflected by the multiple grooves of the grating 50 is dispersed within a plane parallel to the HZ plane. The prism 41 is arranged in such a posture that the incident angle of the first part B1 of the light beam incident on the grating 50 from the prism 41 is the same as the diffraction angle of the light of the desired first wavelength in the diffracted light diffracted by the grating 50. The prism 42 is arranged in such a posture that the incident angle of the second part B2 of the light beam incident on the grating 50 from the prism 42 is the same as the diffraction angle of the light of the desired second wavelength in the diffracted light diffracted by the grating 50. When the incident angles of the light beams incident on the grating 50 from the prisms 41 and 42 are different from each other, a wavelength difference is generated between the first wavelength of the diffracted light returning from the grating 50 to the prism 41 and the second wavelength of the diffracted light returning from the grating 50 to the prism 42.

[0157] At Figure 3AAnd Figure 3B In the figure, the dashed arrow indicating the light beam only shows the direction from the prism 44 towards the grating 50. However, the light beam of the selected wavelength of the narrowbanding device 14 travels from the grating 50 towards the prism 44 in a path opposite to these dashed arrows.

[0158] The prisms 41 - 44 reduce the beam width of the light returning from the grating 50 in a plane parallel to the HZ plane, and cause this light to return to the laser cavity 10 via the window 10a.

[0159] The rotating tables 412 and 422 are controlled by the laser control processor 30 (refer to Figure 2 ).

[0160] When the rotating table 412 slightly rotates the prism 41, the traveling direction of the first part B1 of the light beam emitted from the prism 41 towards the grating 50 slightly changes in a plane parallel to the HZ plane. Thereby, the incident angle of the first part B1 of the light beam incident on the grating 50 from the prism 41 slightly changes. Thereby, the first wavelength changes.

[0161] When the rotating table 422 slightly rotates the prism 42, the traveling direction of the second part B2 of the light beam emitted from the prism 42 towards the grating 50 slightly changes in a plane parallel to the HZ plane. Thereby, the incident angle of the second part B2 of the light beam incident on the grating 50 from the prism 42 slightly changes. Thereby, the second wavelength changes.

[0162] With the above structure and operation, the first wavelength and the second wavelength in the light beam emitted from the window 10a of the laser cavity 10 are selected and returned to the laser cavity 10. Thereby, the narrowbanding gas laser device 1 can perform dual - wavelength oscillation. By controlling the rotating tables 412 and 422, the first wavelength and the second wavelength can also be set separately.

[0163] The focal length in the exposure device 100 (refer to Figure 1 ) depends on the wavelength of the pulsed laser. The pulsed laser output from the narrowbanding gas laser device 1 by performing dual - wavelength oscillation can be imaged at two positions in the direction of the optical axis of the pulsed laser in the workpiece table WT of the exposure device 100, and can substantially increase the depth of focus. For example, in the case of exposing a resist film with a large film thickness, it is also possible to suppress the deviation of the imaging performance in the thickness direction of the resist film.

[0164] 1.3.3 Problems of the Comparative Example

[0165] In the comparative example, the first wavelength and the second wavelength can be set separately. However, it is sometimes difficult to make the cross-sectional shape of the resist film obtained by exposing and developing the resist film into a desired shape. For example, when it is desired that the resist wall surface is close to perpendicular to the surface of the semiconductor wafer, the resist wall surface may sometimes be inclined. The resist wall surface is the boundary surface between the portion where the resist film has been removed by exposure and development and the portion where the resist film remains on the semiconductor wafer.

[0166] In several embodiments described below, the energy ratio between the first wavelength component and the second wavelength component included in the pulsed laser can be adjusted. By being able to adjust the energy ratio, the balance of the exposure state in the thickness direction of the resist film can be adjusted.

[0167] 2. Narrowbanding device capable of adjusting the energy ratio of multiple wavelength components

[0168] 2.1 First embodiment

[0169] 2.1.1 Structure

[0170] Figure 4A and Figure 4B The structure of the narrowbanding device 14a in the first embodiment is schematically shown. Figure 4A The narrowbanding device 14a is shown as viewed in the -V direction, Figure 4B The narrowbanding device 14a is shown as viewed in the -H direction.

[0171] The narrowbanding device 14a includes a parallel plane substrate 61 as a beam shift optical system.

[0172] The parallel plane substrate 61 is disposed on the optical path of the light beam emitted from the window 10a. For example, the parallel plane substrate 61 is disposed on the optical path of the light beam between the window 10a and the prism 44. The parallel plane substrate 61 is supported by a holder 611. The parallel plane substrate 61 is made of a material such as calcium fluoride or synthetic quartz. The parallel plane substrate 61 is disposed such that the surfaces of the parallel plane substrate 61 for the incident and exit of the light beam are both parallel to the V axis. The parallel plane substrate 61 is configured to be rotatable about an axis parallel to the V axis by a rotating table 612. In the first embodiment, the rotating table 612 corresponds to the third actuator in the present disclosure.

[0173] 2.1.2 Operation

[0174] The parallel-plane substrate 61 refracts the light beam so that the surfaces where the light beam incident from the window 10a enters and the surface where the light beam exits toward the prism 44 refract the light beam at the same angle in opposite directions to allow the light beam to pass through. Therefore, the traveling direction of the light beam exiting from the parallel-plane substrate 61 is the same as that of the light beam incident on the parallel-plane substrate 61. Depending on the attitude of the parallel-plane substrate 61, the optical axis is shifted in the H-axis direction. The optical axis refers to the central axis of the optical path.

[0175] The light beam passing through the parallel-plane substrate 61 enters the prism 44 and then enters the prism 43. The prisms 44 and 43 expand the beam width of the light beam in a plane parallel to the HZ plane and allow the light beam to pass through. Moreover, the prism 43 makes the first part B1 of the light beam enter the prism 41 and makes the second part B2 of the light beam enter the prism 42.

[0176] The first part B1 passes through the inside of the prism 41 and enters the grating 50. The second part B2 passes through the inside of the prism 42 and enters the grating 50.

[0177] The rotary stage 612 changes the attitude of the parallel-plane substrate 61. As a result, the shift amount in the H-axis direction when the light beam passes through the parallel-plane substrate 61 changes, and the positions of the light beams incident on the prisms 41 to 44 change in the H-axis direction respectively. Thereby, the energy ratio between the first part B1 and the second part B2 changes. For example, when the parallel-plane substrate 61 is rotated clockwise in Figure 4A , the energy ratio of the first part B1 decreases, and when the parallel-plane substrate 61 is rotated counterclockwise, the energy ratio of the first part B1 increases. Thereby, the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser can be adjusted.

[0178] The exposure control processor 110 (refer to Figure 2 ) sends the target value of the first wavelength, the target value of the second wavelength, and the target value of the energy ratio to the laser control processor 30.

[0179] The laser control processor 30 controls the rotary stage 412 according to the target value of the first wavelength. Thereby, the rotary stage 412 changes the attitude of the prism 41 and adjusts the incident angle (the first incident angle) of the first part B1 of the light beam entering the grating 50.

[0180] The laser control processor 30 controls the rotary stage 422 according to the target value of the second wavelength. Thereby, the rotary stage 422 changes the attitude of the prism 42 and adjusts the incident angle (the second incident angle) of the second part B2 of the light beam entering the grating 50.

[0181] The laser control processor 30 controls the turntable 612 according to the target value of the energy ratio. Thereby, the turntable 612 adjusts the attitude of the parallel plane substrate 61 and adjusts the energy ratio between the first part B1 and the second part B2 of the light beam.

[0182] 2.1.3 Other structural examples

[0183] In the first embodiment, the parallel plane substrate 61 is disposed on the optical path of the light beam between the window 10a and the prism 44. However, the present disclosure is not limited thereto. The parallel plane substrate 61 may also be disposed between the prism 44 and the prism 43 or between the prism 43 and the prisms 41 and 42.

[0184] In the first embodiment, as the beam displacement optical system that displaces the optical axis of the light beam in the H-axis direction, a parallel plane substrate 61 that can rotate about an axis parallel to the V-axis is shown. However, the present disclosure is not limited thereto. By combining a plurality of prisms (not shown) each having an incident and exit surface parallel to the V-axis direction, the optical axis of the light beam can also be displaced in the H-axis direction. By changing the position of at least one of these prisms, the displacement amount in the H-axis direction can also be changed.

[0185] 2.1.4 Function

[0186] In the first embodiment, the narrowbanding device 14a includes: prisms 41 and 42, which are disposed at different positions in the wavelength dispersion direction DD (refer to Figure 3A and Figure 3B ); a prism 43 that expands the beam width of the light beam, makes the first part B1 of the light beam incident on the prism 41, and makes the second part B2 of the light beam incident on the prism 42; and a grating 50 that is disposed to straddle the optical path of the first part B1 after passing through the prism 41 and the optical path of the second part B2 after passing through the prism 42. The turntable 412 serving as the first actuator rotates the prism 41 to adjust the first incident angle of the first part B1 of the light beam incident on the grating 50, and the turntable 422 serving as the second actuator rotates the prism 42 to adjust the second incident angle of the second part B2 of the light beam incident on the grating 50. The turntable 612 serving as the third actuator adjusts the energy ratio between the first part B1 and the second part B2. Thereby, the energy ratio between the first wavelength component and the second wavelength component included in the pulsed laser output from the narrowbanding gas laser device 1 can be adjusted. By using this pulsed laser to expose the resist film, the cross-sectional shape of the resist film can be made into a desired shape.

[0187] In the first embodiment, the narrowbanding device 14a includes a parallel-plane substrate 61 as a beam-shifting optical system. The beam-shifting optical system is disposed on the optical path of the light beam, allows the light beam to pass through, makes the light beam incident on the prism 44, and then incident on the prism 43. The rotating table 612 changes the attitude of the parallel-plane substrate 61, which is at least one optical element included in the beam-shifting optical system. Thus, the beam-shifting optical system can change the position of the light beam incident on the prism 43 from the beam-shifting optical system in a direction intersecting the VZ plane, which is parallel to both the optical axis of the light beam and the grooves of the grating 50. Thereby, the energy ratio between the first part B1 and the second part B2 can be adjusted with a simple structure, and the energy ratio between the first wavelength component and the second wavelength component included in the pulsed laser output from the narrowbanding gas laser device 1 can be adjusted.

[0188] 2.2 First modification

[0189] 2.2.1 Structure and operation

[0190] Figure 5A and Figure 5B Schematically shows the structure of the narrowbanding device 14b in the first modification. Figure 5A Shows the narrowbanding device 14b as viewed in the -V direction, Figure 5B Shows the narrowbanding device 14b as viewed in the -H direction.

[0191] In the narrowbanding device 14b, the prism 43 can be rotated by the rotating table 432 about an axis parallel to the V axis. In the first modification, the rotating table 432 corresponds to the first actuator in the present disclosure.

[0192] In the narrowbanding device 14b, the prism 41 is supported to maintain a fixed attitude.

[0193] In other respects, the structure and operation of the first modification are the same as those of the first embodiment described with reference to Figure 4A and Figure 4B described.

[0194] 2.2.2 Function

[0195] In the first modification, the rotating table 432, which is the first actuator, rotates the prism 43. Thereby, the incident angle of the light beam incident on the grating 50 via the prisms 41 and 42 from the prism 43 changes. Thereby, both the first wavelength and the second wavelength change. In addition, by rotating the prism 42 by the rotating table 422, the second wavelength changes, and the wavelength difference between the first wavelength and the second wavelength can be changed. Therefore, by controlling both the rotating tables 422 and 432, the first wavelength and the second wavelength can be made to approach their respective target values.

[0196] When the prism 43 is rotated, the incident positions of the light beams incident on the prisms 41 and 42 from the prism 43 also change. Therefore, when the prism 43 is rotated, the energy ratio between the first part B1 and the second part B2 also varies. When the energy ratio between the first part B1 and the second part B2 is outside the allowable range due to the rotation of the prism 43, the energy ratio between the first part B1 and the second part B2 can also be adjusted by controlling the attitude of the parallel plane substrate 61.

[0197] 2.3 Second modification example

[0198] 2.3.1 Structure

[0199] Figure 6A and Figure 6B The structure of the narrowbanding device 14c in the second modification example is schematically shown. Figure 6A The narrowbanding device 14c viewed in the -V direction is shown, Figure 6B The narrowbanding device 14c viewed in the -H direction is shown.

[0200] The narrowbanding device 14c includes a linear stage 413.

[0201] The linear stage 413 is configured to move the prisms 41 and 42 integrally together with their respective holders 411, 421 and rotary stages 412, 422. The moving direction of the prisms 41 and 42 realized by the linear stage 413 is a direction intersecting the VZ plane. The direction intersecting the VZ plane is a direction intersecting the plane parallel to both the optical axis of the light beam incident on the prisms 41 and 42 from the prism 43 and the grooves of the grating 50, for example, the wavelength dispersion direction DD of any one of the prisms 41 and 42 (see Figure 3A and Figure 3B ).

[0202] In the second modification example, the linear stage 413 corresponds to the third actuator in the present disclosure. In the second modification example, the parallel plane substrate 61 may be absent (see Figure 4A and Figure 4B ).

[0203] 2.3.2 Operation

[0204] When the linear stage 413 moves the prisms 41 and 42, the energy ratio between the first part B1 of the light beam emitted from the prism 43 and incident on the prism 41 and the second part B2 incident on the prism 42 changes. For example, when the prisms 41 and 42 are moved in the -H2 direction, the energy ratio of the first part B1 decreases, and when the prisms 41 and 42 are moved in the +H2 direction, the energy ratio of the first part B1 increases.

[0205] In other respects, the structure and operation of the second modification example are the same as those of the first embodiment.

[0206] 2.3.3 Other Structural Examples

[0207] In the second modification, it is assumed that the prism 43 maintains a certain posture and the prisms 41 and 42 can rotate. However, the present disclosure is not limited to this. In the second modification, similar to the first modification, it can be assumed that the prism 41 maintains a certain posture and the prisms 42 and 43 can rotate.

[0208] 2.3.4 Function

[0209] In the second modification, the linear stage 413 serving as the third actuator moves the prisms 41 and 42 in a direction intersecting the VZ plane, which is parallel to both the optical axis of the light beam incident on the prisms 41 and 42 from the prism 43 and the grooves of the grating 50. Thereby, even without the parallel flat substrate 61, it is possible to adjust the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser.

[0210] 2.4 Third Modification

[0211] 2.4.1 Structure

[0212] Figure 7A and Figure 7B Schematically shows the structure of the narrowbanding device 14d in the third modification. Figure 7A Shows the narrowbanding device 14d as viewed in the -V direction, Figure 7B Shows the narrowbanding device 14d as viewed in the -H direction.

[0213] The narrowbanding device 14d includes a light shielding plate 71.

[0214] The light shielding plate 71 is arranged to overlap a part of the cross-section of the optical path of the second part B2 of the light beam after passing through the prism 42. The light shielding plate 71 is supported by a holder 711. The light shielding plate 71 is configured to be movable in a direction intersecting the optical axis of the second part B2 through the linear stage 712.

[0215] In the third modification, the linear stage 712 corresponds to the third actuator in the present disclosure. In the third modification, the parallel flat substrate 61 may also be absent.

[0216] 2.4.2 Operation

[0217] The light shielding plate 71 absorbs a part of the second part B2 of the light beam or reflects it outside the optical path of the light beam. Thereby, the energy of the second part B2 incident on the grating 50 is reduced compared to the case without the light shielding plate 71.

[0218] When the position of the light shielding plate 71 is moved on the linear stage 712, the energy incident on the second portion B2 of the grating 50 changes before and after the movement. Thus, the energy ratio between the first portion B1 and the second portion B2 can be adjusted. If the entire optical path cross-section of the second portion B2 is shielded by the light shielding plate 71, the energy ratio of the second portion B2 can be made zero to perform single-wavelength mode laser oscillation. If the entire light shielding plate 71 is retracted from the second portion B2, the energy ratio of the second portion B2 can be maximized.

[0219] In other aspects, the structure and operation of the third modification are the same as those of the first embodiment.

[0220] 2.4.3 Other Structural Examples

[0221] In the third modification, the light shielding plate 71 is disposed on the optical path of the second portion B2 of the light beam between the prism 42 and the grating 50. However, the present disclosure is not limited thereto. The light shielding plate 71 may also be disposed on the optical path of the second portion B2 of the light beam between the prism 43 and the prism 42.

[0222] In the third modification, it is assumed that the prism 43 is maintained in a fixed posture and the prisms 41 and 42 can rotate. However, the present disclosure is not limited thereto. In the third modification, as in the first modification, it may be assumed that the prism 41 is maintained in a fixed posture and the prisms 42 and 43 can rotate. Alternatively, the prism 42 may be maintained in a fixed posture and the prisms 41 and 43 can rotate.

[0223] 2.4.4 Function

[0224] In the third modification, the narrowbanding device 14d includes a light shielding plate 71 configured to overlap a part of the cross-section of the optical path of the second portion B2 of the light beam. The linear stage 712, which is the third actuator, moves the light shielding plate 71 in a direction intersecting the optical path axis of the second portion B2. Thus, even without the parallel plane substrate 61, the energy ratio between the first portion B1 and the second portion B2 can be adjusted.

[0225] 2.5 Fourth Modification

[0226] 2.5.1 Structure

[0227] Figure 8A and Figure 8B Schematically shows the structure of the narrowbanding device 14e in the fourth modification. Figure 8A Shows the narrowbanding device 14e viewed in the -V direction, Figure 8B Shows the narrowbanding device 14e viewed in the -H direction. The narrowbanding device 14e includes, in addition to the parallel plane substrate 61, a parallel plane substrate 62. The parallel plane substrate 62 corresponds to the beam separation optical system in the present disclosure.

[0228] The parallel plane substrate 62 is configured to overlap with a part of the cross-section of the optical path of the light beam after passing through the prism 43. The parallel plane substrate 62 is disposed on the optical path of the second part B2 of the light beam between the prism 43 and the prism 42.

[0229] The parallel plane substrate 62 is supported by a holder 621. The parallel plane substrate 62 is made of a material such as calcium fluoride or synthetic quartz.

[0230] The parallel plane substrate 62 includes an incident surface 623 for a part of the light beam after passing through the prism 43 to enter, and an exit surface 624 for the light that enters the parallel plane substrate 62 through the incident surface 623 to exit from the inside of the parallel plane substrate 62 toward the prism 42. Both the incident surface 623 and the exit surface 624 are parallel to the V axis, and the incident surface 623 and the exit surface 624 are parallel to each other. The incident surface 623 and the exit surface 624 are inclined with respect to the incident direction of the light beam so as to refract the light beam. Specifically, the normal vector 623v of the incident surface 623 is parallel to the HZ plane, and further, this normal vector 623v has direction components in the -H direction and the +Z direction.

[0231] 2.5.2 Operation

[0232] The first part B1 of the light beam after passing through the prism 43 enters the prism 41 through the outside of the parallel plane substrate 62. The second part B2 of the light beam enters the prism 42 through the inside of the parallel plane substrate 62. That is, the narrowbanding device 14e including the parallel plane substrate 62 makes the first part B1 of the light beam enter the prism 41 and makes the second part B2 of the light beam enter the prism 42. At this time, the parallel plane substrate 62 shifts the optical axis of the second part B2 of the light beam in the +H direction with respect to the optical axis of the first part B1. In this way, the parallel plane substrate 62 allows a part of the light beam to pass through, thereby separating the second part B2 from the first part B1 of the light beam.

[0233] The rotary table 612 changes the attitude of the parallel plane substrate 61, whereby the energy ratio between the first part B1 and the second part B2 changes. For example, when the parallel plane substrate 61 is rotated in the Figure 8A clockwise direction, the energy ratio of the first part B1 decreases, and when the parallel plane substrate 61 is rotated counterclockwise, the energy ratio of the first part B1 increases. Thereby, the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser can be adjusted.

[0234] Regarding other aspects, the structure and operation of the fourth modification example are the same as those of the first embodiment.

[0235] 2.5.3 Other Structural Examples

[0236] In the fourth modification, it is assumed that the prism 43 maintains a certain attitude and the prisms 41 and 42 can rotate. However, the present disclosure is not limited to this. In the fourth modification, similar to the first modification, it may be assumed that the prism 41 maintains a certain attitude and the prisms 42 and 43 can rotate. Alternatively, it may be assumed that the prism 42 maintains a certain attitude and the prisms 41 and 43 can rotate.

[0237] In the fourth modification, the attitude of the parallel flat substrate 61 is adjusted to adjust the energy ratio between the first part B1 and the second part B2. However, the present disclosure is not limited to this. The prisms 41 and 42 may be integrally moved with the parallel flat substrate 62 to adjust the energy ratio between the first part B1 and the second part B2. In addition, similar to the third modification, the light shielding plate 71 configured to overlap a part of the cross section of the optical path of the light beam may be moved to adjust the energy ratio between the first part B1 and the second part B2.

[0238] 2.5.4 Function

[0239] In the fourth modification, the narrowbanding device 14e includes the parallel flat substrate 62 as a beam separation optical system configured to overlap a part of the cross section of the optical path of the light beam after passing through the prism 43. The beam separation optical system transmits a part of the light beam, thereby separating the second part B2 from the first part B1. Thereby, waste of the light beam incident between the prism 41 and the prism 42 can be suppressed. In addition, the prisms 41 and 42 can be arranged at intervals from each other, and when the prisms 41 and 42 are rotated respectively, the prisms 41 and 42 can also be arranged outside the rotation radii of each other.

[0240] 2.6 The Fifth Modification

[0241] 2.6.1 Structure

[0242] Figure 9A and Figure 9B Schematically shows the structure of the narrowbanding device 14f in the fifth modification. Figure 9A Shows the narrowbanding device 14f viewed in the -V direction, Figure 9B Shows the narrowbanding device 14f viewed in the -H direction. The narrowbanding device 14f includes a linear stage 622 that moves the parallel flat substrate 62. The linear stage 622 corresponds to the third actuator in the present disclosure. In the fifth modification, the parallel flat substrate 61 may be absent.

[0243] 2.6.2 Operation

[0244] The linear stage 622 moves the parallel plane substrate 62 in a direction intersecting the VZ plane, which is parallel to both the optical path axis of the light beam incident on the parallel plane substrate 62 from the prism 43 and the grooves of the grating 50. By moving the parallel plane substrate 62, the energy ratio between the first part B1 and the second part B2 changes. For example, when the parallel plane substrate 62 is moved in the -H direction, the energy ratio of the first part B1 decreases, and when the parallel plane substrate 62 is moved in the +H direction, the energy ratio of the first part B1 increases. Thus, the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser can be adjusted.

[0245] Regarding other aspects, the structure and operation of the fifth modification are the same as those of the fourth modification.

[0246] 2.6.3 Other Structural Examples

[0247] In the fifth modification, it is assumed that the prism 43 is maintained in a fixed posture and the prisms 41 and 42 can rotate. However, the present disclosure is not limited thereto. In the fifth modification, similar to the first modification, it can be assumed that the prism 41 is maintained in a fixed posture and the prisms 42 and 43 can rotate. Alternatively, it can be assumed that the prism 42 is maintained in a fixed posture and the prisms 41 and 43 can rotate.

[0248] 2.6.4 Function

[0249] In the fifth modification, the beam separation optical system includes the parallel plane substrate 62. The linear stage 622, as the third actuator, moves the parallel plane substrate 62 in a direction intersecting a plane that is parallel to both the optical path axis of the light beam incident on the parallel plane substrate 62 from the prism 43 and the grooves of the grating 50. Thus, even without the parallel plane substrate 61, the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser can be adjusted.

[0250] 3. Narrowbanding Device Including Multiple Gratings

[0251] 3.1 Second Embodiment

[0252] 3.1.1 Structure

[0253] Figure 10A and Figure 10B Schematically shows the structure of the narrowbanding device 14g in the second embodiment. Figure 10A Shows the narrowbanding device 14g as viewed in the -V direction, Figure 10B Shows the narrowbanding device 14g as viewed in the -H direction. The narrowbanding device 14g includes gratings 51 and 52 instead of the grating 50.

[0254] The grating 51 is disposed on the optical path of the first part B1 of the light beam after passing through the prism 41. The grating 52 is disposed on the optical path of the second part B2 of the light beam after passing through the prism 42. The gratings 51 and 52 are respectively supported by the holders 511 and 521. The gratings 51 and 52 can respectively rotate about an axis parallel to the V axis by the rotary tables 512 and 522. In the second embodiment, the rotary tables 512 and 522 respectively correspond to the first and second actuators in the present disclosure.

[0255] In the second embodiment, the prisms 41 and 42 may also be non-rotatable.

[0256] 3.1.2 Operation

[0257] When the rotary table 512 slightly rotates the grating 51, the incident angle of the first part B1 of the light beam incident on the grating 51 from the prism 41 slightly changes. The light of the wavelength diffracted at the diffraction angle consistent with the incident angle returns from the grating 51 to the prism 41. Therefore, the wavelength of the light returning to the prism 41, that is, the first wavelength, changes according to the rotation of the grating 51.

[0258] When the rotary table 522 slightly rotates the grating 52, the incident angle of the second part B2 of the light beam incident on the grating 52 from the prism 42 slightly changes. The light of the wavelength diffracted at the diffraction angle consistent with the incident angle returns from the grating 52 to the prism 42. Therefore, the wavelength of the light returning to the prism 42, that is, the second wavelength, changes according to the rotation of the grating 52.

[0259] By controlling the rotary tables 512 and 522, the first wavelength and the second wavelength can be respectively set.

[0260] In other respects, the structure and operation of the second embodiment are the same as those of the fifth modification.

[0261] 3.1.3 Other Structural Examples

[0262] In the second embodiment, it is assumed that the prisms 41 to 43 are maintained in a fixed posture and the gratings 51 and 52 can rotate. However, the present disclosure is not limited thereto. In the second embodiment, it may also be assumed that any one of the prisms 41 and the grating 51 and any one of the prisms 42, 43 and the grating 52 among the prisms 41 to 43 and the gratings 51 and 52 can rotate, and the other parts are maintained in a fixed posture. Alternatively, it may also be assumed that any one of the prisms 41, 43 and the grating 51 and any one of the prisms 42 and the grating 52 among the prisms 41 to 43 and the gratings 51 and 52 can rotate, and the other parts are maintained in a fixed posture.

[0263] In the second embodiment, the position of the parallel plane substrate 62 is adjusted to adjust the energy ratio between the first part B1 and the second part B2. However, the present disclosure is not limited thereto. Instead of moving the parallel plane substrate 62, the parallel plane substrate 61 may be provided as in the fourth modification example, and the attitude of the parallel plane substrate 61 may be adjusted to adjust the energy ratio between the first part B1 and the second part B2. Further, instead of providing the parallel plane substrate 62, as in the third modification example, the light shielding plate 71 configured to overlap a part of the cross section of the optical path of the light beam may be moved to adjust the energy ratio between the first part B1 and the second part B2.

[0264] 3.1.4 Function

[0265] According to the second embodiment, the narrowbanding device 14g includes the grating 51 disposed on the optical path of the first part B1 of the light beam that has passed through the prism 41, and the grating 52 disposed on the optical path of the second part B2 of the light beam that has passed through the prism 42. Thus, even when the optical paths of the first part B1 and the second part B2 are separated, each light can be received by the gratings 51 and 52.

[0266] Moreover, the linear stage 622 as the third actuator adjusts the energy ratio between the first part B1 and the second part B2. Thereby, the energy ratio between the first wavelength component and the second wavelength component included in the pulsed laser output from the narrowbanding gas laser device 1 can be adjusted.

[0267] According to the second embodiment, the rotary stage 512 as the first actuator rotates the grating 51 about an axis parallel to the grooves of the grating 51, that is, an axis parallel to the V axis. Thus, the first incident angle of the first part B1 of the light beam incident on the grating 51 is adjusted, and the first wavelength can be controlled.

[0268] According to the second embodiment, the rotary stage 522 as the second actuator rotates the grating 52 about an axis parallel to the grooves of the grating 52, that is, an axis parallel to the V axis. Thus, the second incident angle of the second part B2 of the light beam incident on the grating 52 is adjusted, and the second wavelength can be controlled.

[0269] According to the second embodiment, the narrowbanding device 14g includes the parallel plane substrate 62 as a beam separation optical system configured to overlap a part of the cross section of the optical path of the light beam that has passed through the prism 43. The beam separation optical system transmits a part of the light beam, thereby separating the second part B2 from the first part B1. Thus, it is possible to prevent a part of the light beam from being incident between the prism 41 and the prism 42 and wasted. Further, the prisms 41 and 42 can be arranged at intervals from each other, and when the prisms 41 and 42 can be rotated respectively, the prisms 41 and 42 can also be arranged outside the rotation radii of each other.

[0270] According to the second embodiment, the beam separation optical system includes a parallel plane substrate 62. A linear stage 622 serving as a third actuator moves the parallel plane substrate 62 in a direction intersecting a plane that is parallel to both the optical axis of the light beam incident on the parallel plane substrate 62 from the prism 43 and the grooves of the grating 52. Thereby, even without the parallel plane substrate 61, it is possible to adjust the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser.

[0271] 3.2 Sixth modification

[0272] 3.2.1 Structure

[0273] Figure 11A and Figure 11B Schematically shows the structure of the narrowbanding device 14h in the sixth modification. Figure 11A Shows the narrowbanding device 14h viewed in the -V direction, Figure 11B Shows the narrowbanding device 14h viewed in the -H direction.

[0274] The two prisms 41h and 42h included in the narrowbanding device 14h are arranged such that the first part B1 and the second part B2 of the light beam emitted from the prism 43 are refracted in opposite directions from each other. That is, the prism 41h is arranged such that the traveling direction of the first part B1 is bent in the Figure 11A counterclockwise direction so that the first part B1 of the light beam emitted toward the grating 51 is away from the second part B2. The prism 42h is arranged such that the traveling direction of the second part B2 is bent in the Figure 11A clockwise direction so that the second part B2 of the light beam emitted toward the grating 52 is away from the first part B1.

[0275] The prism 42h is located upstream of the prism 41h with respect to the light beam emitted from the prism 43. The prism 42h is configured to be movable by a linear stage 423. In the sixth modification, the linear stage 423 corresponds to the third actuator in the present disclosure. In the sixth modification, the parallel plane substrate 62 may also be absent.

[0276] 3.2.2 Operation

[0277] The linear stage 423 moves the prism 42h in a direction intersecting the VZ plane, which is parallel to both the optical axis of the light beam emitted from the prism 43 toward the prism 42h and the grooves of the grating 52. By moving the prism 42h located upstream of the prism 41h with respect to the light beam, the beam width of the second part B2 changes. Along with this, the beam width of the first part B1 incident on the prism 41h located downstream of the prism 42h with respect to the light beam changes. As a result, the energy ratio between the first part B1 and the second part B2 changes. For example, when the prism 42h is moved in the -H direction, the energy ratio of the first part B1 decreases, and when the prism 42h is moved in the +H direction, the energy ratio of the first part B1 increases. Thus, the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser can be adjusted.

[0278] Regarding other aspects, the structure and operation of the sixth modification are the same as those of the second embodiment.

[0279] 3.2.3 Other Structural Examples

[0280] In the sixth modification, it is assumed that the prisms 41h, 42h, and 43 are maintained in a fixed posture, and the gratings 51 and 52 can rotate. However, the present disclosure is not limited to this. In the sixth modification, it may be assumed that any one of the prisms 41h and 51 and any one of the prisms 42h, 43, and 52 among the prisms 41h, 42h, 43, and the gratings 51 and 52 can rotate, and the other parts are maintained in a fixed posture. Alternatively, it may be assumed that any one of the prisms 41h, 43, and 51 and any one of the prisms 42h and 52 among the prisms 41h, 42h, 43, and the gratings 51 and 52 can rotate, and the other parts are maintained in a fixed posture.

[0281] In the sixth modification, the position of the prism 42h is adjusted to adjust the energy ratio between the first part B1 and the second part B2. However, the present disclosure is not limited to this. Instead of moving the prism 42h, a parallel plane substrate 61 may be provided in the same manner as in the first embodiment, and the posture of the parallel plane substrate 61 may be adjusted to adjust the energy ratio between the first part B1 and the second part B2.

[0282] 3.2.4 Function

[0283] According to the sixth modification example, the narrowbanding device 14h includes a prism 41h that bends the traveling direction of the first part B1 of the light beam so that the first part B1 of the light beam is away from the second part B2, and a prism 42h that bends the traveling direction of the second part B2 of the light beam so that the second part B2 of the light beam is away from the first part B1. Thereby, the optical paths of the first part B1 and the second part B2 are bent in opposite directions to each other. Therefore, the gratings 51 and 52 can be arranged at intervals from each other, and even when the gratings 51 and 52 are rotated respectively, the gratings 51 and 52 can be arranged outside the rotation radii of each other.

[0284] According to the sixth modification example, the linear stage 423 as the third actuator moves the prism 42h in a direction intersecting the VZ plane, and the VZ plane is parallel to both the optical axis of the light beam emitted from the prism 43 and the grooves of the grating 52. Thereby, as a structure for adjusting the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser, the parallel plane substrates 61 and 62 can be dispensed with.

[0285] 3.3 The seventh modification example

[0286] 3.3.1 Structure

[0287] Figure 12A and Figure 12B The structure of the narrowbanding device 14i in the seventh modification example is schematically shown. Figure 12A The narrowbanding device 14i is shown as viewed in the -V direction, Figure 12B The narrowbanding device 14i is shown as viewed in the -H direction.

[0288] The narrowbanding device 14i includes a light shielding plate 71.

[0289] The light shielding plate 71 is arranged to overlap a part of the cross section of the optical path of the second part B2 of the light beam after passing through the prism 42h. The light shielding plate 71 is supported by a holder 711. The light shielding plate 71 is configured to be movable in a direction intersecting the optical axis of the second part B2 of the light beam by a linear stage 712.

[0290] In the seventh modification example, the linear stage 712 corresponds to the third actuator in the present disclosure. In the seventh modification example, the linear stage 423 for moving the prism 42h may be absent.

[0291] 3.3.2 Operation

[0292] The light shielding plate 71 absorbs a part of the second part B2 of the light beam or reflects it outside the optical path of the light beam. Thereby, the energy of the second part B2 incident on the grating 52 is reduced compared to the case where there is no light shielding plate 71.

[0293] When the position of the light shielding plate 71 is moved on the linear stage 712, the energy incident on the second part B2 of the grating 52 changes before and after the movement. Thereby, the energy ratio between the first part B1 and the second part B2 can be adjusted. If the entire optical path cross-section of the second part B2 is shielded by the light shielding plate 71, the energy ratio of the second part B2 can be made 0 to perform single-wavelength mode laser oscillation. If the entire light shielding plate 71 is retracted from the second part B2, the energy ratio of the second part B2 can be maximized.

[0294] In other respects, the structure and operation of the seventh modification are the same as those of the sixth modification.

[0295] 3.3.3 Other structural examples

[0296] In the seventh modification, the light shielding plate 71 is disposed on the optical path of the second part B2 of the light beam between the prism 42h and the grating 52. However, the present disclosure is not limited thereto. The light shielding plate 71 may also be disposed on the optical path of the second part B2 of the light beam between the prism 43 and the prism 42h. In addition, the light shielding plate 71 may also be disposed on the optical path of the first part B1 of the light beam between the prism 43 and the grating 51.

[0297] In the seventh modification, it is assumed that the prisms 41h, 42h, and 43 are maintained in a fixed posture and the gratings 51 and 52 can rotate. However, the present disclosure is not limited thereto. In the seventh modification, it may also be assumed that either one of the prisms 41h and 51 and either one of the prisms 42h, 43, and 52 among the prisms 41h, 42h, 43, and the gratings 51 and 52 can rotate, and the other parts are maintained in a fixed posture. Alternatively, it may also be assumed that either one of the prisms 41h, 43, and 51 and either one of the prisms 42h and 52 among the prisms 41h, 42h, 43, and the gratings 51 and 52 can rotate, and the other parts are maintained in a fixed posture.

[0298] 3.3.4 Function

[0299] According to the seventh modification, the narrowbanding device 14i includes a light shielding plate 71 configured to overlap a part of the cross-section of the optical path of the second part B2 of the light beam. The linear stage 712, which is the third actuator, moves the light shielding plate 71 in a direction intersecting the optical path axis of the second part B2. Thereby, as a structure for adjusting the energy ratio between the first wavelength component and the second wavelength component of the pulsed laser, the parallel flat substrates 61 and 62 can be dispensed with.

[0300] 4. Others

[0301] The above description is not a limitation but a simple illustration. Therefore, those skilled in the art will understand that modifications can be made to the embodiments of the present disclosure without departing from the claims. In addition, those skilled in the art will also understand to use the embodiments of the present disclosure in combination.

[0302] As long as it is not explicitly stated, the terms used throughout this specification and the claims should be construed as "non-limiting" terms. For example, terms such as "comprising," "having," "including," and "possessing" should be construed as not excluding the existence of structural elements other than those recited. In addition, the modifier "one" should be construed as meaning "at least one" or "one or more." Further, a phrase such as "at least one of A, B, and C" should be construed as "A," "B," "C," "A + B," "A + C," "B + C," or "A + B + C." Moreover, it should be construed as also including combinations with parts other than A, B, and C.

Claims

1. A narrowbanding device, comprising: A first prism and a second prism, which are arranged at different positions in the wavelength dispersion direction of any one of the first prism and the second prism; A third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and makes a first part of the light beam incident on the first prism and a second part of the light beam incident on the second prism; A grating, which is arranged to straddle the optical path of the first part after passing through the first prism and the optical path of the second part after passing through the second prism; A first actuator, which adjusts the incident angle of the first part incident on the grating; A second actuator, which adjusts the incident angle of the second part incident on the grating; And A third actuator, which adjusts the energy ratio between the first part and the second part.

2. The narrowbanding device according to claim 1, wherein The first actuator rotates the first prism.

3. The narrowbanding device according to claim 1, wherein The second actuator rotates the second prism.

4. The narrowbanding device according to claim 1, wherein The narrowbanding device further has a beam shift optical system, which is arranged on the optical path of the light beam, allows the light beam to pass through, and makes the light beam incident on the third prism. Wherein, by changing the position or attitude of at least one optical element included in the beam shift optical system by the third actuator, thereby changing the position of the light beam incident on the third prism from the beam shift optical system in a direction intersecting a plane that is parallel to both the optical axis of the light beam and the grooves of the grating.

5. The narrowbanding device according to claim 4, wherein The beam shift optical system includes a parallel plane substrate, The third actuator rotates the parallel plane substrate.

6. The narrowbanding device according to claim 1, wherein The first actuator rotates the third prism.

7. The narrowbanding device according to claim 1, wherein The third actuator moves the first prism and the second prism in a direction intersecting a plane that is parallel to both the optical axis of the light beam incident on the first prism and the second prism from the third prism and the grooves of the grating.

8. The narrowbanding device according to claim 1, wherein The narrowbanding device further includes a light shielding plate, which is configured to overlap a part of the cross section of the optical path of the second part, The third actuator moves the light shielding plate in a direction intersecting the optical axis of the second part.

9. The narrowbanding device according to claim 1, wherein The narrowbanding device further has a beam separation optical system, which is configured to overlap a part of the cross section of the optical path of the light beam after passing through the third prism. The beam separation optical system allows a part of the light beam to pass through, thereby separating the second part from the first part.

10. The narrowbanding device according to claim 9, wherein The beam separation optical system includes a parallel plane substrate, The third actuator moves the parallel plane substrate in a direction intersecting a plane that is parallel to both the optical path axis of the light beam incident on the parallel plane substrate from the third prism and the grooves of the grating.

11. A narrowbanding device, comprising: A first prism and a second prism, which are arranged at different positions in the wavelength dispersion direction of any one of the first prism and the second prism; A third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and makes the first part of the light beam incident on the first prism and the second part of the light beam incident on the second prism; A first grating, which is arranged on the optical path of the first part after passing through the first prism; A second grating, which is arranged on the optical path of the second part after passing through the second prism; A first actuator, which adjusts the incident angle of the first part incident on the first grating; A second actuator, which adjusts the incident angle of the second part incident on the second grating; And A third actuator, which adjusts the energy ratio between the first part and the second part.

12. The narrowbanding device according to claim 11, wherein The first actuator rotates the first grating about an axis parallel to the grooves of the first grating.

13. The narrowbanding device according to claim 11, wherein The second actuator rotates the second grating about an axis parallel to the grooves of the second grating.

14. The narrowbanding device according to claim 11, wherein The narrowbanding device further includes a beam separation optical system, which is configured to overlap with a part of the cross-section of the optical path of the light beam after passing through the third prism, and the beam separation optical system allows a part of the light beam to pass through, thereby separating the second part from the first part.

15. The narrowbanding device according to claim 14, wherein The beam separation optical system includes a parallel plane substrate, The third actuator moves the parallel plane substrate in a direction intersecting a plane that is parallel to both the optical path axis of the light beam incident on the parallel plane substrate from the third prism and the grooves of the second grating.

16. The narrowbanding device according to claim 11, wherein The first prism bends the traveling direction of the first part away from the second part with respect to the traveling direction of the light beam exiting from the third prism toward the first prism, The second prism bends the traveling direction of the second part away from the first part with respect to the traveling direction of the light beam exiting from the third prism toward the second prism.

17. The narrowbanding device according to claim 16, wherein The third actuator moves the second prism in a direction intersecting a plane that is parallel to both the optical path axis of the light beam incident on the second prism from the third prism and the grooves of the second grating.

18. The narrowbanding device according to claim 11, wherein The narrowbanding device further includes a light-shielding plate configured to overlap a part of the cross-section of the optical path of the second part. The third actuator moves the light-shielding plate in a direction intersecting the optical path axis of the second part.

19. A method for manufacturing an electronic device, comprising the following steps: Generating pulsed laser light by a laser device. Outputting the pulsed laser light to an exposure device. Exposing the pulsed laser light on a photosensitive substrate in the exposure device to manufacture an electronic device. The laser device includes a laser cavity and an optical resonator including a narrowbanding device. The narrowbanding device has: A first prism and a second prism, which are arranged at positions different in the wavelength dispersion direction of any one of the first prism and the second prism. A third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and causes a first part of the light beam to enter the first prism and a second part of the light beam to enter the second prism. A grating, which is configured to span the optical path of the first part after passing through the first prism and the optical path of the second part after passing through the second prism. A first actuator, which adjusts the incident angle of the first part incident on the grating. A second actuator, which adjusts the incident angle of the second part incident on the grating. And A third actuator, which adjusts the energy ratio between the first part and the second part.

20. A method for manufacturing an electronic device, comprising the following steps: Generating pulsed laser light by a laser device. Outputting the pulsed laser light to an exposure device. Exposing the pulsed laser light on a photosensitive substrate in the exposure device to manufacture an electronic device. The laser device includes a laser cavity and an optical resonator including a narrowbanding device. The narrowbanding device has: A first prism and a second prism, which are arranged at positions different in the wavelength dispersion direction of any one of the first prism and the second prism. A third prism, which is arranged on the optical path of the light beam, expands the beam width of the light beam, and causes a first part of the light beam to enter the first prism and a second part of the light beam to enter the second prism. A first grating, which is arranged on the optical path of the first part after passing through the first prism. A second grating, which is arranged on the optical path of the second part after passing through the second prism. A first actuator, which adjusts the incident angle of the first part incident on the first grating. A second actuator, which adjusts the incident angle of the second part incident on the second grating. And A third actuator, which adjusts the energy ratio between the first part and the second part.

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