Optical pulse expander, laser device, and method for manufacturing electronic device

Abstract

The invention provides an optical pulse expander, a laser apparatus, and a method of manufacturing an electronic device. This optical pulse expander is provided with: a beam splitter that splits laser light incident on an optical surface into reflected laser light and transmitted laser light; a holder that fixes the beam splitter so that the optical surface of the beam splitter is inclined with respect to the optical path axis of the incident laser light; a plurality of reflectors that guide the reflected laser light to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction parallel to the optical surface, the sliding mechanism being provided with: a sliding plate that is connected to the holder; and a housing that holds the sliding plate so as to be movable in the sliding direction with respect to the substrate on which the plurality of mirrors are disposed, the housing being provided with a threaded hole having an internal thread formed on the inner circumference, and the sliding plate being provided with a through hole at a position corresponding to the threaded hole.

Description

Technical Field

[0001] The present disclosure relates to an optical pulse stretcher, a laser device, and a method for manufacturing an electronic device. Background Art

[0002] In recent years, in semiconductor exposure devices, as semiconductor integrated circuits become smaller and more highly integrated, there is a demand for improved resolution. Therefore, the wavelength of light emitted from an exposure light source is being shortened. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs a laser with a wavelength of about 248nm and an ArF excimer laser device that outputs a laser with a wavelength of about 193nm are used.

[0003] The spectral line width of the natural oscillation light of the KrF excimer laser device and the ArF excimer laser device is relatively wide, at 350 to 400 pm. Therefore, if the projection lens is made of a material that transmits ultraviolet rays such as KrF and ArF lasers, chromatic aberration may sometimes occur. As a result, the resolution may be reduced. Therefore, it is necessary to narrow the spectral line width of the laser output from the gas laser device to a level where the chromatic aberration can be ignored. Therefore, in order to narrow the spectral line width, a narrowing module (Line Narrowing Module: LNM) including narrowing elements (etalon, grating, etc.) is sometimes provided in the laser resonator of the gas laser device. Hereinafter, a gas laser device with a narrowed spectral line width is referred to as a narrowed gas laser device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-130113

[0007] Patent Document 2: U.S. Patent No. 9322934

[0008] Patent Document 3: Japanese Patent No. 5352278

[0009] Patent Document 4: Japanese Patent Application Publication No. 2015-155933 Summary of the invention

[0010] An optical pulse stretcher according to one aspect of the present disclosure comprises: a beam splitter that separates laser light incident on an optical surface into reflected laser light and transmitted laser light; a holder that fixes the beam splitter so that the optical surface of the beam splitter is tilted relative to the optical path axis of the incident laser light; a plurality of mirrors that guide the reflected laser light to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction parallel to the optical surface, the sliding mechanism comprising: a sliding plate connected to the holder; and a housing that holds the sliding plate so that it can move in a sliding direction relative to a substrate on which the plurality of mirrors are arranged, the housing comprising a threaded hole having an internal thread formed on the inner circumference, and the sliding plate comprising a through hole at a position corresponding to the threaded hole.

[0011] A laser device according to one aspect of the present disclosure comprises: a pair of electrodes that generate discharge; and an optical pulse expander that expands the pulse width of a pulse laser generated by the discharge generated between the electrodes, the optical pulse expander comprising: a beam splitter that separates laser light incident on an optical surface into reflected laser light and transmitted laser light; a holder that fixes the beam splitter so that the optical surface of the beam splitter is tilted relative to the optical path axis of the incident laser light; a plurality of mirrors that guide the reflected laser light to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction parallel to the optical surface, the sliding mechanism comprising: a sliding plate connected to the holder; and a housing that holds the sliding plate so that it can move relative to a substrate on which the plurality of mirrors are arranged, the housing comprising a threaded hole, and the sliding plate comprising a through hole at a position corresponding to the threaded hole.

[0012] In a method for manufacturing an electronic device according to one aspect of the present disclosure, a laser device generates a laser beam with a pulse width expanded, outputs the laser beam to an exposure device, and exposes the laser beam to a photosensitive substrate in the exposure device to manufacture the electronic device. The laser device includes: a pair of electrodes that generate discharge; and an optical pulse expander that expands the pulse width of the pulse laser beam generated by the discharge generated between the electrodes, the optical pulse expander includes: a beam splitter that separates the laser beam incident on an optical surface into reflected laser beam and transmitted laser beam; a holder that fixes the beam splitter so that the optical surface of the beam splitter is tilted relative to the optical path axis of the incident laser beam; a plurality of reflective mirrors that guide the reflected laser beam to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction parallel to the optical surface, the sliding mechanism includes: a sliding plate connected to the holder; and a housing that holds the sliding plate so that it can move relative to a substrate on which the plurality of reflective mirrors are arranged, the housing includes a threaded hole, and the sliding plate includes a through hole at a position corresponding to the threaded hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings, merely as examples.

[0014] Figure 1 FIG. 1 is a diagram schematically showing the structure of an exemplary laser device.

[0015] Figure 2 It is a perspective view showing another example of an optical pulse stretcher.

[0016] Figure 3 This is a schematic diagram showing a slide mechanism of the beam splitter.

[0017] Figure 4 This is a schematic diagram showing a slide mechanism of the beam splitter.

[0018] Figure 5 This is a diagram showing a state where the beam splitter is arranged at the first position by the sliding mechanism.

[0019] Figure 6 It is a diagram showing a state where the beam splitter is arranged at the second position by the sliding mechanism.

[0020] Figure 7 yes Figure 6 Cross-sectional view at line 7-7 in FIG.

[0021] Figure 8 This is a diagram for explaining the problem of the sliding mechanism.

[0022] Fig. 9 This is a schematic diagram showing the sliding mechanism of the beam splitter according to the first embodiment.

[0023] Fig.10 This is a schematic diagram showing the sliding mechanism of the beam splitter according to the first embodiment.

[0024] Fig.11 It is a diagram for explaining the fixation of the case and the plate.

[0025] Fig.12 This is a schematic diagram showing the sliding mechanism of the beam splitter according to the second embodiment.

[0026] Fig.13 yes Fig.12 A cross-sectional view taken along line 13-13 in FIG.

[0027] Fig.14 This is a diagram schematically showing a configuration example of an exposure apparatus. DETAILED DESCRIPTION

[0028] - Contents - 1. Overview of laser device

[0029] 1.1 Structure

[0030] 1.2 Action

[0031] 2.Other examples of OPS

[0032] 2.1 Structure

[0033] 2.2 Actions

[0034] 2.3 Effects

[0035] 3. Sliding mechanism of beam splitter

[0036] 3.1 Structure

[0037] 3.2 Actions

[0038] 3.3 Action and Effect

[0039] 4.Topics

[0040] 5. Implementation Method 1

[0041] 5.1 Structure

[0042] 5.2 Actions

[0043] 5.3 Effects

[0044] 6. Implementation Method 2

[0045] 6.1 Structure

[0046] 6.2 Actions

[0047] 6.3 Effects

[0048] 7. Implementation Method 3

[0049] 7.1 Structure

[0050] 7.2 Action / Effect

[0051] 8. Method for manufacturing electronic devices

[0052] 9. Others

[0053] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below represent several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and actions described in each embodiment may not all be necessary for the structures and actions of the present disclosure. In addition, the same reference symbols are marked on the same components, and repeated descriptions are omitted.

[0054] 1. Overview of laser equipment

[0055] 1.1 Structure

[0056] Figure 1 1 is a diagram schematically showing the structure of an exemplary laser device 2. The laser device 2 is an excimer laser device including a master oscillator (MO) 10, a MO beam steering unit 20, a power oscillator (PO) 30, a PO beam steering unit 40, and an optical pulse stretcher (OPS) 50.

[0057] MO10 includes LNM11, chamber 14, and output coupling mirror (OC) 18. LNM11 includes prism beam expander 12 and grating 13 for narrowing the spectrum width. Prism beam expander 12 and grating 13 are configured in Littrow configuration to make the incident angle and diffraction angle consistent.

[0058] OC18 is a partial reflective mirror, and is arranged to form an optical resonator together with LNM11. The reflectivity of OC18 can be, for example, 40% to 60%.

[0059] The chamber 14 is arranged on the optical path of the optical resonator. The chamber 14 includes a pair of discharge electrodes 15a, 15b and two windows 16a, 16b for laser light to pass through. Excimer laser gas is introduced into the chamber 14. The excimer laser gas includes, for example, Ar gas or Kr gas as a rare gas, F2 gas as a halogen gas, and Ne gas as a buffer gas.

[0060] The MO beam steering unit 20 includes a high reflection mirror 21 and a high reflection mirror 22 , and is configured to make the pulse laser output from the MO 10 incident on the PO 30 .

[0061] PO 30 includes a rear mirror 37, a cavity 34, and an OC 38. The rear mirror 37 and the OC 38 constitute an optical resonator, and the cavity 34 is arranged on the optical path of the optical resonator.

[0062] The structure of the chamber 34 may be the same as that of the chamber 14. That is, the chamber 34 includes a pair of discharge electrodes 35a, 35b and two windows 36a, 36b for laser light to pass through. Excimer laser gas is introduced into the chamber 34. The rear mirror 37 is a partial reflector with a reflectivity of 50% to 90%. The OC 38 is a partial reflector with a reflectivity of 10% to 30%.

[0063] The PO beam steering unit 40 includes a high reflection mirror 43 and a high reflection mirror 44. These high reflection mirrors 43 and 44 are configured to make the pulse laser output from the PO 30 incident on the OPS 50.

[0064] OPS50 is an example of an "optical pulse stretcher" in the present disclosure. OPS 50 includes a beam splitter 53 and four concave mirrors 54a, 54b, 54c and 54d. The beam splitter 53 is arranged on the optical path of the pulse laser output from the PO beam steering unit 40. The beam splitter 53 is a partial reflection mirror that allows a part of the incident pulse laser to pass through and allows the other pulse laser to reflect. That is, the beam splitter 53 separates the incident pulse laser into reflected laser light and transmitted laser light. The reflectivity of the beam splitter 53 can be, for example, 60%. The beam splitter 53 allows the pulse laser light that passes through the beam splitter 53 to be output from the laser device 2.

[0065] The four concave mirrors 54a to 54d constitute a delayed optical path of the pulsed laser reflected by the first surface of the beam splitter 53. The four concave mirrors 54a to 54d are arranged so that the pulsed laser reflected by the first surface of the beam splitter 53 is reflected by the four concave mirrors 54a to 54d and enters the beam splitter 53 again.

[0066] The four concave mirrors 54a to 54d may be concave mirrors having substantially the same focal length. The focal length f of each of the concave mirrors 54a to 54d may correspond to the distance from the beam splitter 53 to the concave mirror 54a, for example.

[0067] The concave mirrors 54a and 54b are configured so that the pulsed laser reflected by the first surface of the beam splitter 53 is reflected by the concave mirror 54a and incident on the concave mirror 54b. The concave mirrors 54a and 54b are configured so that the pulsed laser reflected by the first surface of the beam splitter 53 is formed into a first image in the same magnification (1:1) as the image on the first surface of the beam splitter 53.

[0068] The concave mirrors 54c and 54d are configured so that the pulsed laser reflected by the concave mirror 54b is reflected by the concave mirror 54c and incident on the concave mirror 54d. Furthermore, the concave mirror 54d is configured so that the pulsed laser reflected by the concave mirror 54d is incident on the second surface of the beam splitter 53 opposite to the first surface. The concave mirrors 54c and 54d are configured so that the first image is formed as a second image on the second surface of the beam splitter 53 at a magnification of 1:1. The four concave mirrors 54a to 54d are an example of the "plurality of reflection mirrors" in the present disclosure.

[0069] 1.2 Action

[0070] When discharge occurs in the chamber 14 of the MO 10, the laser gas is excited, and pulsed laser light narrowed by the optical resonator formed by the OC 18 and the LNM 11 is output from the OC 18. The pulsed laser light passes through the MO beam steering unit 20 and enters the rear mirror 37 of the PO 30 as seed light.

[0071] In synchronization with the timing when the seed light transmitted through the rear mirror 37 is incident on the chamber 34, discharge is generated in the chamber 34. As a result, the laser gas is excited, the seed light is amplified by the Fabry-Perot type optical resonator composed of the OC 38 and the rear mirror 37, and the amplified pulse laser is output from the OC 38. The pulse laser output from the OC 38 is incident on the OPS 50 via the PO beam steering unit 40. The pulse width of the pulse laser is expanded by the OPS 50.

[0072] The pulsed laser after passing through OPS50 can be incident on the beam characteristic measurement device through a monitor module (not shown). The monitor module is a module that measures pulse energy, spectral line width, wavelength, etc. The beam characteristic measurement device is a module that measures direction, divergence, polarization, etc. Figure 1, an example is shown in which one stage of OPS 50 is provided, but the laser device 2 may include two or more stages of OPS. For example, one or more OPSs (not shown) may be arranged in series on the optical path of the pulse laser output from the OPS 50.

[0073] 2.Other examples of OPS

[0074] 2.1 Structure

[0075] Figure 2 FIG. 1 is a perspective view showing another example of an optical pulse stretcher. Figure 2 The two-stage OPS51 shown in the figure is used instead Figure 1 OPS50 described in.

[0076] OPS 51 includes a first OPS module 510 and a second OPS module 520. The first OPS module 510 includes a beam splitter BS1, an annular optical path LP1, and a housing CS1 including a base plate BP1. The annular optical path LP1 is a delayed optical path composed of concave mirrors CM11-CM18 and a collection window HW1.

[0077] The second OPS module 520 includes a beam splitter BS2, a ring light path LP2, and a housing CS2 including a substrate BP2. The ring light path LP2 is a delay light path formed by concave mirrors CM21-CM24 and a collecting window HW2.

[0078] Each optical element is held by a holder (not shown), and each holder is positioned on each substrate BP1, BP2. Each substrate BP1, BP2 can constitute any surface of each housing CS1, CS2, but Figure 2 In the example shown, a surface parallel to the HV plane near the front side of each housing CS1, CS2 is formed. The discharge direction of the discharge electrodes 35a, 35b is set as the V direction, and the direction parallel to the optical path axis of the laser incident on the OPS51 is set as the Z direction. In addition, the direction perpendicular to the V direction and the Z direction is set as the H direction. The discharge electrodes 35a, 35b are an example of a "pair of electrodes" in the present disclosure.

[0079] It should be noted that, in this specification, the term "orthogonal" or "perpendicular" is not limited to the situation of being strictly orthogonal or perpendicular, as long as it is not clearly stated, and includes the concept of being approximately orthogonal or approximately perpendicular, and the approximately orthogonal or approximately perpendicular includes the range of the angle difference allowed in practical use without losing the technical significance. In addition, in this specification, the term "parallel" is not limited to the situation of being strictly parallel, as long as it is not clearly stated, and includes the concept of being approximately parallel, and the approximately parallel includes the range of the angle difference allowed in practical use without losing the technical significance.

[0080] The housing CS1 is formed with openings OP1 and OP2 for passing laser light. The opening OP1 is an entrance port for the laser light to enter the first OPS module 510, and the opening OP2 is an exit port for the laser light from the first OPS module 510. Similarly, the housing CS2 is formed with an opening OP3 as an entrance port for the laser light and an opening OP4 as an exit port.

[0081] The concave mirrors CM11 to CM18, CM21 to CM24 are respectively arranged at both ends of the housings CS1 and CS2 in the V direction in a manner facing each other. That is, the concave mirrors CM11, CM15, CM13, and CM17 of the first OPS module 510 are arranged in sequence on the bottom side of the housing CS1 in a direction parallel to the H direction, and the concave mirrors CM18, CM14, CM16, and CM12 are arranged in sequence on the top side of the housing CS1 in a direction parallel to the H direction. Thus, the concave mirror CM11 is arranged in a manner facing the concave mirror CM18 via the beam splitter BS1.

[0082] Similarly, concave mirrors CM15, CM13 and CM17 are arranged to face concave mirrors CM14, CM16 and CM12. The annular optical path LP1 is constructed such that the light reflected by the beam splitter BS1 is reflected in the order of concave mirrors CM11, CM12, CM13, CM14, CM15, CM16, CM17 and CM18 and returns to the beam splitter BS1.

[0083] In addition, the concave mirrors CM21 and CM23 of the second OPS module 520 are sequentially arranged in a direction parallel to the H direction on the bottom side of the housing CS2, and the concave mirrors CM24 and CM22 are sequentially arranged in a direction parallel to the H direction on the top side of the housing CS2. Thus, the concave mirror CM21 is arranged to face the concave mirror CM24 across the beam splitter BS2, and the concave mirror CM23 is arranged to face the concave mirror CM22. The annular optical path LP2 is configured such that the light reflected by the beam splitter BS2 is reflected in the order of the concave mirrors CM21, CM22, CM23, and CM24, and returns to the beam splitter BS2.

[0084] Each of the beam splitters BS1 and BS2 is located on the optical path of the pulse laser light output from the PO beam steering unit 40 .

[0085] Each collecting window HW1, HW2 is arranged between the final concave mirror CM18, CM24 and the beam splitter BS1, BS2 in each ring optical path LP1, LP2.

[0086] 2.2 Action

[0087] The pulse laser output from PO30 enters the beam splitter BS1 through the opening OP1, a part of it is transmitted and the rest is reflected. The pulse laser reflected by the beam splitter BS1 propagates in the annular optical path LP1, passes through the collection window HW1, and is thus combined with the pulse laser transmitted through the beam splitter BS1 with high precision and output.

[0088] A portion of the pulse laser light incident on the beam splitter BS1 again passes through and the rest is reflected. The pulse laser light reflected here is combined with the pulse laser light passing through the beam splitter BS1 without passing through the ring light path LP1. In this way, the pulse width is expanded by sequentially superimposing the pulse laser light passing through the ring light path LP1 on the pulse laser light passing through the beam splitter BS1. The pulse laser light passing through the ring light path LP1 passes through the collection window HW1, so that the optical path does not deviate whenever it propagates in the ring light path LP1.

[0089] Likewise, the pulse laser output from the first OPS module 510 is incident on the beam splitter BS2, and the pulse width is further expanded during propagation in the ring optical path LP2.

[0090] 2.3 Effects

[0091] according to Figure 2 The OPS51 shown can greatly expand the pulse width through the first-stage ring light path LP1 and the second-stage ring light path LP2, thereby suppressing the generation of speckles. In addition, since the pulse width is expanded, the energy value per unit time irradiated to the subsequent optical system is reduced, suppressing the degradation of the optical system.

[0092] 3. Sliding mechanism of beam splitter

[0093] 3.1 Structure

[0094] Figure 3 and Figure 4 This is a schematic diagram showing a slide mechanism of the beam splitter. Figure 3 This is a diagram viewed from a direction (Z direction) parallel to the optical path axis of the laser light transmitted through the beam splitter 150 . Figure 4 yes Figure 3 A partial cross-sectional view taken along line 4-4 in FIG.

[0095] The slide mechanism 200 includes a beam splitter (BS) holder 210 that holds the BS 150, plates 212, 213, 214, and plate holders 220a, 220b. The beam splitter 150 may be Figure 1 The beam splitter 53 shown or Figure 2 Any of the beam splitters BS1, BS2 shown.

[0096] The beam splitter 150 is fixed to the BS holder 210. The beam splitter 150 is arranged in a state where an optical surface 151 on which laser light is incident is inclined at 45 degrees with respect to the optical path axis of the pulse laser light output from the PO beam steering unit 40.

[0097] The BS holder 210 is fixed to the plate 212 using the BS holder fixing screws 211a and 211b provided on the side of the BS holder 210. The axis of each of the BS holder fixing screws 211a and 211b is parallel to the optical surface 151 of the beam splitter 150. The plate 212 is fixed to the plate 213. The plate 213 is fixed to the plate 214. Thus, the BS holder 210 and the plate 214 are connected.

[0098] The plate 214 has a V-direction reference surface 232V and a Z-direction reference surface 232Z. The V-direction reference surface 232V is perpendicular to the V direction and is a surface that defines the V-direction reference position of the beam splitter 150. The Z-direction reference surface 232Z is ​​perpendicular to the Z direction and is a surface that defines the Z-direction reference position of the beam splitter 150. The plate 214 is an example of a “sliding plate” in the present disclosure.

[0099] Figure 5 This is a diagram showing a state where the beam splitter 150 is arranged at the first position by the slide mechanism 200 . Figure 6 This is a diagram showing a state where the beam splitter 150 is arranged at the second position by the slide mechanism 200 . Figure 7 yes Figure 5 A partial cross-sectional view taken along line 7-7 in FIG.

[0100] The plate holders 220a and 220b are fixed to the housing 300 using bolts 222a and 222b, so that the plate 214 contacts the reference surfaces 310V and 310Z on the housing 300 side, and the plate 214 is held to be able to slide along the reference surfaces 310V and 310Z. The reference surface 310V is a housing reference surface perpendicular to the V direction. The reference surface 310Z is a housing reference surface perpendicular to the Z direction.

[0101] The housing 300 may be Figure 2 The shell CS1 or shell CS2 shown in the figure. In addition, the reference plane 310V and the reference plane 310Z can also be formed on Figure 2 In order to make the V-direction reference surface 232V and the Z-direction reference surface 232Z of the plate 214 contact reliably with the reference surface 310V and the reference surface 310Z on the housing 300 side, the plate 214 is pressed by the reaction force of the spring arranged on the plunger 224, 225, 226, etc. (not shown).

[0102] A plunger 224 that acts in the Z direction is attached to the plate holder 220a. A plunger 225 that acts in the Z direction and a plunger 226 that acts in the V direction are attached to the plate holder 220b.

[0103] The plungers 224, 225 are aligned with the plate 214. Figure 7 The Z direction reference surface 232Z (reference Figure 4 ) is pressed against the reference surface 310Z on the housing 300 side. Figure 7 The plate 214 is forced from the upper side to the lower side (-V direction), and the V direction reference surface 232V (reference Figure 4 ) is pressed against a reference surface 310V on the shell 300 side.

[0104] By the reaction force of the plungers 224, 225, and 226, the V-direction reference surface 232V and the Z-direction reference surface 232Z contact the reference surface 310V and the reference surface 310Z on the housing 300 side, respectively, and the plate 214 can slide along the reference surface 310V and the reference surface 310Z. That is, the plate 214 can slide in the ±H directions while maintaining the position in the V direction and the Z direction. The ±H directions are sometimes referred to as sliding directions.

[0105] A rod 250 extending in the H direction is connected to the plate 214 so that a force can be applied to the plate 214 from the outside of the housing 300 to move the plate 214 in the sliding direction. The rod 250 passes through a through hole 320 formed in the housing 300 and extends to the outside of the housing 300. An O-ring 322 for sealing to maintain airtightness in the housing 300 is arranged in the through hole 320, and the rod 250 contacts the O-ring 322 and can move in the sliding direction. A handle 252 is provided at the end of the rod 250 extending to the outside of the housing 300.

[0106] In addition, the handle 252 is formed with positioning grooves 254a and 254b for limiting the position in the sliding direction. Figure 5 ) and the second position ( Figure 6 ) is an example of two positioning grooves 254a and 254b corresponding to the two positions, but it is also possible to have positioning grooves corresponding to more than three positions. The positioning groove 254a is an example of a "first recess" in the present disclosure, the positioning groove 254b is an example of a "second recess" in the present disclosure, and the positioning grooves 254a and 254b are examples of "multiple recesses" in the present disclosure.

[0107] The housing 300 is provided with a plunger 326 for positioning in the sliding direction. The plunger 326 is fixed to a support member 328 extending from the housing 300. The plunger 326 is engaged with any one of the plurality of positioning grooves 254a and the positioning grooves 254b to limit the position of the plate 214 in the sliding direction and perform positioning. The plunger 326 is an example of a "positioning plunger" in the present disclosure. The positioning mechanism including the positioning grooves 254a, 254b and the plunger 326 is an example of a "positioning mechanism" in the present disclosure. The handle 252 having the positioning grooves 254a and 254b is an example of a "engaged member" in the present disclosure.

[0108] 3.2 Action

[0109] The plate 214 can shift the laser irradiation position on the beam splitter 150 while maintaining the orientation of the optical surface 151 by sliding in a direction perpendicular to the optical path axis (Z axis) and parallel to the optical surface 151 of the beam splitter 150. The direction parallel to the optical surface 151 of the beam splitter 150 may be a direction intersecting with a maintenance surface of a housing (not shown) of the laser device 2, or a direction passing through a maintenance opening provided on the maintenance surface. The maintenance surface is a surface perpendicular to the H direction.

[0110] like Figure 5 As shown, by engaging the plunger 326 with the positioning groove 254 a of the handle 252 , the plate 214 and the beam splitter 150 that can slide integrally with the plate 214 are positioned in the first position.

[0111] In addition, from Figure 5 From the state, the field engineer operates the handle 252 to pull out the rod 250, such as Figure 6 As shown, the plunger 326 is engaged with the positioning groove 254b of the handle 252, thereby positioning the plate 214 and the beam splitter 150 in the second position.

[0112] The movement amount (sliding amount) of the sliding mechanism 200 in the sliding direction is preferably preset so that the irradiation area LA1 of the laser beam splitter 150 at the first position and the irradiation area LA2 of the laser beam splitter 150 at the second position do not overlap.

[0113] For example, the laser device 2 is initially used at a first position to irradiate the beam splitter 150 with laser light, and after the optical characteristics of a portion of the beam splitter 150 deteriorate, the beam splitter 150 is moved to a second position to irradiate the remaining non-degraded region with laser light.

[0114] 3.3 Effects

[0115] The beam splitter 150 deteriorates due to laser irradiation (energy transmittance deteriorates). According to the slide mechanism 200, by moving the beam splitter 150, the laser irradiation position on the beam splitter 150 can be shifted, and the laser can be irradiated to a non-degraded position. In this way, by using the beam splitter 150 to avoid the degraded position, the frequency of replacement can be reduced, and a long life of the beam splitter 150 can be expected. The number of slides for shifting the laser irradiation position depends on the size of the beam splitter 150 and the size of the laser irradiation area, and is typically about 2 to 5 times.

[0116] The change in the element arrangement angle of the beam splitter 150 has little influence on the emitted light, and realignment by sliding the beam splitter 150 alone is not necessary.

[0117] As a result, even if part of the beam splitter 150 is deteriorated, there is no need to replace the OPS module, and the module usage time can be extended several times, thereby reducing the running cost.

[0118] Furthermore, according to the slide mechanism 200 , the beam splitter 150 can be slid while the inside of the housing 300 is kept sealed, and downtime associated with maintenance work can be reduced.

[0119] 4.Topics

[0120] Figure 8 This is a diagram used to explain the subject of the sliding mechanism. Figure 7 When the BS holder 210 is fixed to the plate 212, the BS holder fixing screws 211a and 211b on the side of the BS holder 210 are tightened with a predetermined torque. Figure 8 As shown in FIG. 1 , when torque is applied to the BS holder fixing screws 211a and 211b in the clockwise direction as the tightening direction, a force acts on the plate 214 in a direction away from the housing 300 with the housing 300 as a fulcrum, and the plunger 225 may shrink due to the force. As a result, a gap may be generated between the Z-direction reference surface 232Z of the plate 214 and the reference surface 310Z on the housing 300 side.

[0121] When such a gap occurs, the beam splitter 150 cannot be maintained at a predetermined position and angle relative to the reference plane 310Z. Therefore, it is difficult to adjust and check the optical axis while applying torque to the BS holder fixing screws 211a and 211b.

[0122] Therefore, an object of the present invention is to suppress the angular deviation of the beam splitter 150 even when a rotational force is applied to the plate 214 as when the BS holder 210 is replaced.

[0123] 5. Implementation Method 1

[0124] 5.1 Structure

[0125] Fig. 9 and Fig.10 This is a schematic diagram showing the sliding mechanism of the beam splitter according to the first embodiment. Fig. 9 This is a diagram observed from a direction parallel to the optical path axis of the laser beam passing through the beam splitter 150 (Z direction). Fig.10 yes Fig. 9 A partial cross-sectional view at line 10-10 in FIG.

[0126] The housing 300 has a non-through screw hole 301 having an internal thread formed on the inner periphery on the reference surface 310Z in contact with the plate 214. The position of the screw hole 301 in the V direction is between the hole for inserting the bolt 222a and the hole for inserting the bolt 222b of the housing 300. The position of the screw hole 301 in the H direction is the same as the hole for inserting the bolt 222a and the hole for inserting the bolt 222b of the housing 300. The screw hole 301 is an example of a "threaded hole" in the present disclosure.

[0127] The plate 214 has a through hole 215B at a position corresponding to the screw hole 301. The through hole 215B penetrates from the surface to which the plate 213 is fixed to the Z direction reference surface 232Z (see Figure 4 ). The through hole 215B is a non-threaded hole without an internal thread formed on the inner circumference, and its diameter is larger than the screw hole 301. Fig. 9 In the example of , the position corresponding to the screw hole 301 is a position where the through hole 215B is coaxial with the screw hole 301 when the beam splitter 150 is arranged in the second position. The through hole 215B is an example of a “through hole” in the present disclosure.

[0128] exist Fig. 9 In the example shown, two screw holes 301 are provided in the housing 300, and two through holes 215B corresponding to the two screw holes 301 are provided in the plate 214. In this way, a plurality of pairs of screw holes 301 and through holes 215B may be provided.

[0129] In addition, the plate 214 may also have a through hole 215A at a position corresponding to the screw hole 301 when the beam splitter 150 is arranged at the first position. The through hole 215A penetrates from the surface to which the plate 213 is fixed to the Z-direction reference surface 232Z in the Z direction. The through hole 215A is a non-threaded hole with no internal thread formed on the inner circumference, and has a diameter larger than the screw hole 301.

[0130] The through hole provided in the plate 214 may also be in the shape of a long hole extending in the H direction so that it is located at a position corresponding to the screw hole 301 when the beam splitter 150 is configured in any position from the first position to the second position.

[0131] 5.2 Action

[0132] Before applying torque to the BS holder fixing screws 211 a and 211 b , field engineers etc. fix the housing 300 and the plate 214 , so that no gap is generated between the Z direction reference surface 232Z of the plate 214 and the reference surface 310Z on the housing 300 side even if torque is applied.

[0133] Fig.11 2 is a diagram for explaining the fixing of the housing 300 and the plate 214. Fig.11 As shown, the slide plate fixing screw 216 is fastened to the screw hole 301 via the through hole 215B, thereby fixing the housing 300 and the plate 214. The slide plate fixing screw 216 may also be fastened to the screw hole 301 via the through hole 215A.

[0134] Next, the field engineer or the like applies torque to the BS holder fixing screws 211 a and 211 b to fix the BS holder 210 to the plate 214 .

[0135] Finally, the field engineer or the like removes the slide plate fixing screws 216. This allows the beam splitter 150 to slide.

[0136] 5.3 Effects

[0137] According to the structure of the first embodiment, the angular deviation of the beam splitter 150 when torque is applied to the BS holder fixing screws 211a and 211b, that is, the optical axis deviation of the beam splitter 150 can be alleviated. Therefore, assembly adjustment and confirmation of the optical axis while applying torque are facilitated.

[0138] 6. Implementation Method 2

[0139] 6.1 Structure

[0140] Fig.12 200B is a schematic diagram showing a slide mechanism of a beam splitter according to Embodiment 2. The slide mechanism 200B includes a plate 240 and a rod 260. Fig.12 In the figure, the beam splitter 150, the BS holder 210, the BS holder fixing screws 211a and 211b, the plate 212, and the plate 213 are omitted.

[0141] The plate 240 is fixed to the side surface 234 of the plate 214 which is parallel to the VZ plane by screws not shown. The plate 240 includes two upright portions 242A and 242B. The upright portion 242A includes a hook portion 244A facing the upright portion 242B at the front end. The upright portion 242B includes a hook portion 244B facing the upright portion 242A at the front end. The plate 240 is an example of a "plate portion" in the present disclosure.

[0142] The rod 260 passes through the through hole 320 formed in the housing 300. The handle 252 is provided at the end of the rod 260 located outside the housing 300. The circular flange portion 262 protruding radially outward of the rod 260 is provided at the end of the rod 260 located inside the housing 300, and the front end of the rod 260 has a T-shaped cross section.

[0143] The distance between the hook portion 244A and the hook portion 244B of the plate 240 is larger than the diameter of the rod 260 and smaller than the diameter of the flange portion 262. The length of the upright portions 242A and 242B of the plate 240 in the H direction is larger than the length of the flange portion 262 in the H direction. The rod 260 passes through the hook portion 244A and the hook portion 244B of the plate 240, and the flange portion 262 is held in a manner that there is a gap in the space surrounded by the plate 240 and the plate 214. As a result, the rod 260 is connected to the plate 214 in a floating manner, and the sliding axis of the plate 214 is uniaxial. The hook portion 244 and the flange portion 262 are examples of the "transmission member" in the present disclosure.

[0144] 6.2 Action

[0145] When the on-site engineer operates the handle 252 to move the rod 260 to Fig.12 When the rod 260 is pulled out from right to left (H direction), the flange 262 of the rod 260 is hooked on the hooking parts 244A and 244B of the plate 240, and the plate 240 transmits the displacement of the rod 260 in the H direction to the plate 214. As a result, the on-site engineer can move the plate 214 in the H direction.

[0146] In addition, when the on-site engineer operates the handle 252 to move the rod 260 to Fig.12 When the rod 260 is pushed in from left to right (-H direction), the flange 262 of the rod 260 contacts the side surface 234 of the plate 214, and the displacement of the rod 260 in the -H direction is transmitted to the plate 214. As a result, the field engineer can move the plate 214 in the -H direction.

[0147] In addition, the displacement of the rod 260 in a direction different from the ±H directions is restricted from being transmitted to the plate 214 .

[0148] 6.3 Effects

[0149] Due to the floating of the plate 214 and the rod 260, the displacement of the rod 260 in the sliding direction is transmitted to the plate 214, and the displacement in the direction different from the sliding direction of the rod 260 is not transmitted. As a result, the sliding axis becomes an axis along the reference plane 310V. Therefore, the eccentricity and deflection of the reference plane 310V on the side of the rod 260 and the housing 300 can be absorbed. As a result, it can be expected that the push-pull operability such as light operability can be improved and the angular deviation of the beam splitter during push-pull can be further alleviated.

[0150] 7. Implementation Method 3

[0151] 7.1 Structure

[0152] Fig.13 is a schematic diagram showing the sliding mechanism of the beam splitter of Embodiment 3. Fig.12 The cross-sectional view at line 13-13 in FIG. Fig.13 Only the peripheries of both end portions of the plate 214 are shown.

[0153] like Fig.13 As shown, in the sliding mechanism 200C, the shapes of both ends of the Z-direction reference surface 232Z, which is the contact surface with the housing 300 in the plate 214 in the sliding direction, are set to be chamfered at 30 degrees and have a curvature radius R5.

[0154] That is, the plate 214 has inclined surfaces 232C at both ends of the Z-direction reference surface 232Z in the sliding direction. The inclined surface 232C is a surface inclined with respect to the sliding direction, and connects the Z-direction reference surface 232Z and the side surface 234. The angle of the inclined surface 232C with respect to the sliding direction is 30 degrees. The angle of the inclined surface 232C with respect to the sliding direction is preferably not less than 10 degrees and not more than 45 degrees.

[0155] In addition, the plate 214 includes a curved surface 232R having a curvature radius between the Z-direction reference surface 232Z and the inclined surface 232C. The curvature radius of the curved surface 232R is 5 mm. The curvature radius of the curved surface 232R is preferably 3 mm or more and 15 mm or less.

[0156] Furthermore, the material of the plate 214 may be SUS 440C having a relatively high hardness. Thus, the Z-direction reference surface 232Z and the V-direction reference surface 232V pressed by the plungers 224, 225, and 226 may be formed of a hard material such as stainless steel. Furthermore, the plate 214 may be quenched or coated.

[0157] 7.2 Action / Effect

[0158] According to the sliding mechanism 200C, the push-pull resistance in the sliding direction is reduced by the inclined surface 232C and the curved surface 232R, so that vibration during push-pull can be suppressed. Therefore, it is expected that the angular deviation of the beam splitter 150 during push-pull can be further alleviated.

[0159] Furthermore, according to the sliding mechanism 200C, the hardness is increased due to the change in material, so that the indentation caused by the ball plug is reduced, and contamination of the surface of the beam splitter 150 due to dust generation is suppressed.

[0160] 8. Method for manufacturing electronic devices

[0161] Fig.14800 is a diagram schematically showing a configuration example of an exposure device 800. The exposure device 800 includes an illumination optical system 806 and a projection optical system 808. The laser device 2 generates laser light and outputs the laser light to the exposure device 800. The illumination optical system 806 illuminates the mask pattern of the mask (not shown) arranged on the mask stage RT using the laser light incident from the laser device 2. The projection optical system 808 projects the laser light transmitted through the mask in a reduced size so that it is imaged on the workpiece (not shown) arranged on the workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist.

[0162] The exposure device 800 causes the mask stage RT and the work stage WT to move in parallel synchronously, thereby exposing the workpiece to the laser reflecting the mask pattern. After the mask pattern is transferred to the semiconductor wafer through the above exposure process, a semiconductor device can be manufactured through multiple processes. A semiconductor device is an example of an "electronic device" in the present disclosure.

[0163] 9. Others

[0164] The above description is not limiting but merely illustrative. Therefore, it is obvious to those skilled in the art that the embodiments of the present disclosure can be changed without departing from the claims. In addition, it is also obvious to those skilled in the art that the embodiments of the present disclosure can be used in combination.

[0165] Unless expressly stated, the terms used in this specification and claims should be interpreted as "non-restrictive" terms. For example, terms such as "including", "having", "having", and "having" should be interpreted as "not excluding the existence of constituent elements other than the recorded constituent elements". In addition, the modifier "one" should be interpreted as meaning "at least one" or "one or more". In addition, the term "at least one of A, B and C" should be interpreted as "A", "B", "C", "A+B", "A+C", "B+C" or "A+B+C". Furthermore, it should be interpreted to also include combinations of them with parts other than "A", "B" and "C".

Claims

1. An optical pulse stretcher, wherein: The optical pulse stretcher has: A beam splitter that separates the laser light incident on the optical surface into reflected laser light and transmitted laser light; a holder for fixing the beam splitter so that an optical surface of the beam splitter is tilted relative to an optical path axis of the incident laser light; a plurality of mirrors that direct the reflected laser light to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction parallel to the optical surface, The sliding mechanism comprises: a sliding plate coupled to the retaining frame; and a housing that holds the slide plate so as to be movable in a sliding direction relative to the substrate on which the plurality of reflectors are arranged, The housing has a threaded hole with an internal thread formed on the inner circumference. The slide plate includes a through hole at a position corresponding to the screw hole.

2. The optical pulse stretcher according to claim 1, wherein: The housing has a plurality of threaded holes. The slide plate has a plurality of through holes corresponding to the plurality of threaded holes, respectively.

3. The optical pulse stretcher according to claim 1, wherein: The housing includes a first threaded hole corresponding to a first position of the sliding plate and a second threaded hole corresponding to a second position of the sliding plate away from the first position.

4. The optical pulse stretcher according to claim 3, wherein: The optical pulse stretcher further includes a positioning mechanism that limits the position of the sliding plate in the sliding direction. The positioning mechanism comprises: an engaged member having a plurality of recesses including a first recess for configuring the sliding plate at a first position in the sliding direction and a second recess for configuring the sliding plate at a second position in the sliding direction; and A positioning plunger is engaged with any one of the plurality of recesses.

5. The optical pulse stretcher according to claim 1, wherein: The sliding plate includes the through hole in the shape of an elongated hole extending in the sliding direction.

6. The optical pulse stretcher according to claim 1, wherein: The optical pulse stretcher includes a holder fixing screw that connects the holder and the slide plate.

7. The optical pulse stretcher according to claim 6, wherein: The axis of the holder fixing screw is parallel to the optical surface.

8. The optical pulse stretcher according to claim 7, wherein: The optical pulse stretcher includes a plunger for urging the slide plate toward the housing. The sliding plate is forced in a direction away from the housing due to the tightening of the retainer fixing screws. The force in a direction away from the housing is greater than the force applied by the plunger to the housing.

9. The optical pulse stretcher according to claim 1, wherein: The through hole is a non-threaded hole having no internal thread formed on the inner circumference.

10. The optical pulse stretcher according to claim 1, wherein: The optical pulse stretcher includes a slide plate fixing screw that is fastened to the threaded hole via the through hole.

11. The optical pulse stretcher according to claim 1, wherein: The optical pulse stretcher has: a rod movable along the sliding direction; and a transmission member that transmits the displacement of the rod to the sliding plate, The transmission member transmits displacement of the rod in the sliding direction and restricts transmission of displacement of the rod in a direction different from the sliding direction.

12. The optical pulse stretcher according to claim 11, wherein: The transmission component comprises: a plate portion disposed on the sliding plate; and a flange portion provided on the rod, As the rod moves, the flange portion comes into contact with the slide plate or the plate portion, and the displacement of the rod in the sliding direction is transmitted to the slide plate.

13. The optical pulse stretcher according to claim 1, wherein: The sliding plate comprises: a contact surface, which contacts the housing; A side surface of the sliding plate in the sliding direction; and An inclined surface is inclined relative to the sliding direction and connects the contact surface with the side surface.

14. The optical pulse stretcher according to claim 13, wherein: The angle of the inclined surface with respect to the sliding direction is greater than or equal to 10 degrees and less than or equal to 45 degrees.

15. The optical pulse stretcher according to claim 13, wherein: The sliding plate includes a curved surface having a curvature radius between the contact surface and the inclined surface.

16. The optical pulse stretcher according to claim 15, wherein: The radius of curvature is greater than or equal to 3 mm and less than or equal to 15 mm.

17. The optical pulse stretcher according to claim 1, wherein: The sliding plate is made of stainless steel.

18. The optical pulse stretcher according to claim 17, wherein: The stainless steel is SUS 440C.

19. A laser device, wherein: The laser device comprises: a pair of electrodes that generate an electrical discharge; and an optical pulse stretcher that stretches the pulse width of a pulse laser generated by discharge between the electrodes, The optical pulse stretcher has: A beam splitter that separates the laser light incident on the optical surface into reflected laser light and transmitted laser light; a holder for fixing the beam splitter so that an optical surface of the beam splitter is tilted relative to an optical path axis of the incident laser light; a plurality of mirrors that direct the reflected laser light to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction parallel to the optical surface, The sliding mechanism comprises: a sliding plate coupled to the retaining frame; and a housing that holds the slide plate so as to be movable relative to the substrate on which the plurality of reflectors are arranged, The housing has a threaded hole. The slide plate includes a through hole at a position corresponding to the screw hole.

20. A method for manufacturing an electronic device, wherein: The laser device generates a laser with a pulse width extended. outputting the laser to an exposure device, exposing the photosensitive substrate to the laser in the exposure device to manufacture an electronic device, The laser device comprises: a pair of electrodes that generate an electrical discharge; and an optical pulse stretcher that stretches the pulse width of the pulse laser generated by the discharge generated between the electrodes, The optical pulse stretcher has: A beam splitter that separates the laser light incident on the optical surface into reflected laser light and transmitted laser light; a holder for fixing the beam splitter so that an optical surface of the beam splitter is tilted relative to an optical path axis of the incident laser light; a plurality of mirrors that direct the reflected laser light to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction parallel to the optical surface, The sliding mechanism comprises: a sliding plate coupled to the retaining frame; and a housing that holds the slide plate so as to be movable relative to the substrate on which the plurality of reflectors are arranged, The housing has a threaded hole. The slide plate includes a through hole at a position corresponding to the screw hole.

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