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

Abstract

To provide an optical pulse expander that is used for a gas laser device.SOLUTION: An optical pulse expander comprises: a beam splitter that separates a laser beam entering into an optical surface into a reflection laser beam and a transmissivity laser beam; a holder 210 that fixes the beam splitter so as to be inclined to an optical path of the laser beam entering to the optical surface of the beam splitter; a plurality of mirrors that guide the reflection laser beam to the beam splitter; and a slide mechanism that moves the beam splitter in a direction that is parallel to the optical surface. The slide mechanism comprises: a slide plate 214 to which the holder is coupled; and a case 300 that movably holds the slide plate in a slide direction with respect to a base plate on which the plurality of mirrors are arranged. The case comprises a screw hole 301 in which a female screw is formed. The slide plate comprises a penetration hole 215B positioned at a position corresponded to the screw hole.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to optical pulse stretchers, laser apparatus, and methods of manufacturing electronic devices. [Background technology]

[0002] In recent years, in semiconductor exposure devices, there is a demand for improved resolution as semiconductor integrated circuits become finer and more highly integrated. For this reason, the wavelength of light emitted from exposure light sources is becoming shorter. For example, as gas laser devices for exposure, KrF excimer laser devices that output laser light with a wavelength of about 248 nm and ArF excimer laser devices that output laser light with a wavelength of about 193 nm are used.

[0003] The spectral line width of the spontaneous oscillation light of the KrF excimer laser device and the ArF excimer laser device is as wide as 350 to 400 pm. Therefore, if a projection lens is made of a material that transmits ultraviolet light such as KrF and ArF laser light, chromatic aberration may occur. As a result, the resolution may decrease. Therefore, it is necessary to narrow the spectral line width of the laser light 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 line narrowing module (LNM) including a narrowing element (such as an etalon or a grating) may be provided in the laser resonator of the gas laser device. Hereinafter, a gas laser device in which the spectral line width is narrowed is referred to as a narrow-line gas laser device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-130113 A [Patent Document 2] U.S. Patent No. 9,322,934 [Patent Document 3] Patent No. 5352278 [Patent Document 4] Summary of JP2015-155933A

[0005] An optical pulse stretcher according to one aspect of the present disclosure comprises a beam splitter that splits laser light incident on an optical surface into a reflected laser light and a transmitted laser light, a holder that fixes the beam splitter by tilting the optical surface of the beam splitter with respect 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 slide mechanism that moves the beam splitter in a direction parallel to the optical surface, wherein the slide mechanism comprises a slide plate to which the holder is connected and a case that holds the slide plate movably in a sliding direction relative to a base plate on which the plurality of mirrors are arranged, the case having a screw hole with a female thread formed on its inner circumference, and the slide plate having a through hole at a position corresponding to the screw hole.

[0006] A laser device according to one aspect of the present disclosure includes a pair of electrodes that generate a discharge, and an optical pulse stretcher that stretches a pulse width of a pulsed laser beam generated by the discharge generated between the electrodes. The optical pulse stretcher includes a beam splitter that separates a laser beam incident on an optical surface into a reflected laser beam and a transmitted laser beam, a holder that fixes the beam splitter by tilting the optical surface of the beam splitter with respect to an optical path axis of the incident laser beam, a plurality of mirrors that guide the reflected laser beam to the beam splitter, and a slide mechanism that moves the beam splitter in a direction parallel to the optical surface. The slide mechanism includes a slide plate to which the holder is connected, and a case that movably holds the slide plate relative to a base plate on which a plurality of mirrors are arranged, the case having a screw hole, and the slide plate having a through hole at a position corresponding to the screw hole.

[0007] a holder for fixing the beam splitter by tilting the optical surface of the beam splitter with respect to an optical path axis of the incident laser light; a plurality of mirrors for guiding the reflected laser light to the beam splitter; and a slide mechanism for moving the beam splitter in a direction parallel to the optical surface, the slide mechanism comprising: a slide plate to which the holder is connected; and a case in which the plurality of mirrors are disposed and which movably holds the slide plate relative to a base plate, the case having a screw hole and the slide plate having a through hole at a position corresponding to the screw hole. The method includes generating laser light having a stretched pulse width by a laser apparatus, outputting the laser light to an exposure apparatus, and exposing a photosensitive substrate to the laser light in the exposure apparatus to manufacture an electronic device. [Brief description of the drawings]

[0008] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings. [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of an exemplary laser device. [Diagram 2] FIG. 2 is a perspective view showing another embodiment of the optical pulse stretcher. [Diagram 3] FIG. 3 is a schematic diagram showing a sliding mechanism of the beam splitter. [Figure 4] FIG. 4 is a schematic diagram showing a sliding mechanism of the beam splitter. [Diagram 5] FIG. 5 is a diagram showing a state in which the beam splitter is placed at the first position by the slide mechanism. [Figure 6] FIG. 6 is a diagram showing a state in which the beam splitter is placed at the second position by the slide mechanism. [Figure 7] FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. [Figure 8] FIG. 8 is a diagram for explaining the problem with the slide mechanism. [Figure 9] FIG. 9 is a schematic diagram showing a sliding mechanism of the beam splitter according to the first embodiment. [Figure 10] FIG. 10 is a schematic diagram showing a sliding mechanism of the beam splitter according to the first embodiment. [Figure 11] FIG. 11 is a diagram for explaining the fixing of the case and the plate. [Figure 12] FIG. 12 is a schematic diagram showing a sliding mechanism of the beam splitter according to the second embodiment. [Figure 13] FIG. 13 is a cross-sectional view taken along line 13-13 in FIG. [Figure 14] FIG. 14 is a diagram illustrating an example of the configuration of an exposure apparatus. Embodiment

[0009] -table of contents- 1. Overview of the laser device 1.1 Configuration 1.2 Operation 2.Other examples of OPS formats 2.1 Configuration 2.2 Operation 2.3 Actions and Effects 3. Beam splitter sliding mechanism 3.1 Configuration 3.2 Operation 3.3 Actions and Effects 4. Challenges 5. Embodiment 1 5.1 Configuration 5.2 Operation 5.3 Actions and Effects 6. Embodiment 2 6.1 Configuration 6.2 Operation 6.3 Actions and Effects 7. Embodiment 3 7.1 Configuration 7.2 Actions and Effects 8. Manufacturing method of electronic devices 9.Other Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure, and do not limit the contents of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and duplicated explanations will be omitted.

[0010] 1. Overview of the laser device 1.1 Configuration 1 is a diagram illustrating a schematic configuration of an exemplary laser device 2. The laser device 2 is an excimer laser device including a master oscillator (MO) 10, an MO beam steering unit 20, a power oscillator (PO) 30, a PO beam steering unit 40, and an optical pulse stretcher (OPS) 50.

[0011] The MO 10 includes an LNM 11, a chamber 14, and an output coupling mirror (OC) 18. The LNM 11 includes a prism beam expander 12 for narrowing the spectral width, and a grating 13. The prism beam expander 12 and the grating 13 are arranged in a Littrow arrangement so that the angle of incidence and the angle of diffraction match.

[0012] The OC 18 is a partial reflection mirror, and is disposed so as to configure an optical resonator together with the LNM 11. The reflectance of the OC 18 may be, for example, 40% to 60%.

[0013] The chamber 14 is disposed on the optical path of the optical resonator. The chamber 14 includes a pair of discharge electrodes 15a, 15b and two windows 16a, 16b through which the laser light passes. An 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.

[0014] The MO beam steering unit 20 includes a high-reflection mirror 21 and a high-reflection mirror 22, and is disposed so that the pulsed laser light output from the MO 10 is incident on the PO 30.

[0015] The PO 30 includes a rear mirror 37, a chamber 34, and an OC 38. The rear mirror 37 and the OC 38 configure an optical resonator, and the chamber 34 is disposed on the optical path of the optical resonator.

[0016] The configuration 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 through which the laser light passes. An excimer laser gas is introduced into the chamber 34. The rear mirror 37 is a partial reflection mirror with a reflectance of 50% to 90%. The OC 38 is a partial reflection mirror with a reflectance of 10% to 30%.

[0017] 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 disposed so that the pulsed laser light output from the PO 30 is incident on the OPS 50.

[0018] The OPS 50 is an example of an "optical pulse stretcher" in this disclosure. The OPS 50 includes a beam splitter 53 and four concave mirrors 54a, 54b, 54c, and 54d. The beam splitter 53 is disposed on the optical path of the pulsed laser light output from the PO beam steering unit 40. The beam splitter 53 is a partial reflection mirror that transmits a part of the pulsed laser light incident thereon and reflects the remaining pulsed laser light. That is, the beam splitter 53 separates the incident pulsed laser light into a reflected laser light and a transmitted laser light. The reflectance of the beam splitter 53 may be, for example, 60%. The beam splitter 53 outputs the pulsed laser light transmitted through the beam splitter 53 from the laser device 2.

[0019] The four concave mirrors 54a to 54d form a delay optical path for the pulsed laser light reflected by the first surface of the beam splitter 53. The pulsed laser light reflected by the first surface of the beam splitter 53 is arranged to be reflected by the four concave mirrors 54a to 54d and enter the beam splitter 53 again.

[0020] The four concave mirrors 54a to 54d may have 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.

[0021] The concave mirrors 54a and 54b are arranged so that the pulsed laser light 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 arranged so that the pulsed laser light reflected by the first surface of the beam splitter 53 forms an image on the first surface of the beam splitter 53 at the same magnification (1:1) as a first image.

[0022] The concave mirrors 54c and 54d are arranged so that the pulsed laser light 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 arranged so that the pulsed laser light reflected by the concave mirror 54d is incident on a second surface of the beam splitter 53 opposite to the first surface. The concave mirrors 54c and 54d are arranged so that the first image is formed as a second image on the second surface of the beam splitter 53 at a 1:1 ratio. The four concave mirrors 54a to 54d are an example of the "plurality of mirrors" in this disclosure.

[0023] 1.2 Operation When a discharge occurs in the chamber 14 of the MO 10, the laser gas is excited, and a pulsed laser beam narrowed in band by the optical resonator composed of the OC 18 and the LNM 11 is output from the OC 18. This pulsed laser beam is incident on the rear mirror 37 of the PO 30 as a seed beam by the MO beam steering unit 20.

[0024] A discharge occurs in the chamber 34 in synchronization with the timing at which the seed light transmitted through the rear mirror 37 enters the chamber 34. As a result, the laser gas is excited, the seed light is amplified by a Fabry-Perot type optical resonator formed by the OC 38 and the rear mirror 37, and the amplified pulsed laser light is output from the OC 38. The pulsed laser light output from the OC 38 enters the OPS 50 via the PO beam steering unit 40. The pulse width of the pulsed laser light is expanded by the OPS 50.

[0025] The pulsed laser light that has passed through the OPS 50 may pass through a monitor module (not shown) and enter a beam characteristic measuring device. The monitor module is a module that measures pulse energy, spectral linewidth, wavelength, etc. The beam characteristic measuring device is a module that measures pointing, divergence, degree of polarization, etc. Although FIG. 1 shows an example including a single stage of OPS 50, 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 pulsed laser light output from the OPS 50.

[0026] 2.Other examples of OPS formats 2.1 Configuration Fig. 2 is a perspective view showing another embodiment of the optical pulse stretcher. Instead of the OPS 50 described in Fig. 1, an OPS 51 having a two-stage configuration as shown in Fig. 2 may be used.

[0027] The OPS 51 includes a first OPS module 510 and a second OPS module 520. The first OPS module 510 includes a beam splitter BS1, a loop optical path LP1, and a case CS1 including a base plate BP1. The loop optical path LP1 is a delay optical path configured with concave mirrors CM11 to CM18 and a halving window HW1.

[0028] The second OPS module 520 is composed of a beam splitter BS2, a loop optical path LP2, and a case CS2 including a base plate BP2. The loop optical path LP2 is a delay optical path composed of concave mirrors CM21 to CM24 and a halving window HW2.

[0029] Each optical element is held by a holder (not shown), and each holder is positioned on each base plate BP1, BP2. Each base plate BP1, BP2 may form any surface of each case CS1, CS2, but in the example shown in FIG. 2, it forms a surface parallel to the HV plane on the front side of each case CS1, CS2. The discharge direction of the discharge electrodes 35a, 35b is the V direction, and the direction parallel to the optical path axis of the laser light incident on the OPS 51 is the Z direction. The direction perpendicular to the V direction and the Z direction is the H direction. The discharge electrodes 35a, 35b are an example of a "pair of electrodes" in this disclosure.

[0030] In this specification, the terms "orthogonal" and "perpendicular" are not limited to strictly orthogonal or perpendicular, unless otherwise specified, but include the concept of approximately orthogonal or approximately perpendicular, including a range of angle difference that is practically acceptable without losing its technical meaning. In addition, in this specification, the term "parallel" is not limited to strictly parallel, but includes the concept of approximately parallel, including a range of angle difference that is practically acceptable without losing its technical meaning, unless otherwise specified.

[0031] The case CS1 has openings OP1 and OP2 through which the laser light passes. The opening OP1 is an entrance port for the laser light to 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 case CS2 has openings OP3, which is an entrance port for the laser light, and opening OP4, which is an exit port.

[0032] The concave mirrors CM11 to CM18, CM21 to CM24 are arranged to face each other at both ends of the cases CS1 and CS2 in the V direction. That is, the concave mirrors CM11, CM15, CM13, and CM17 of the first OPS module 510 are arranged in this order on the bottom side of the case CS1 in a direction parallel to the H direction, and the concave mirrors CM18, CM14, CM16, and CM12 are arranged in this order on the top side of the case CS1 in a direction parallel to the H direction. As a result, the concave mirror CM11 is arranged to face the concave mirror CM18 with the beam splitter BS1 in between.

[0033] Similarly, concave mirrors CM15, CM13, and CM17 are arranged to face concave mirrors CM14, CM16, and CM12. The loop optical path LP1 is configured so that light reflected by the beam splitter BS1 is reflected by concave mirrors CM11, CM12, CM13, CM14, CM15, CM16, CM17, and CM18 in this order, and returns to the beam splitter BS1.

[0034] Furthermore, the concave mirrors CM21 and CM23 of the second OPS module 520 are arranged side by side in this order in a direction parallel to the H direction on the bottom side of the case CS2, and the concave mirrors CM24 and CM22 are arranged side by side in this order in a direction parallel to the H direction on the top side of the case CS2. As a result, 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 loop optical path LP2 is configured so that the light reflected by the beam splitter BS2 is reflected by the concave mirrors CM21, CM22, CM23, and CM24 in that order, and returns to the beam splitter BS2.

[0035] Each of the beam splitters BS1 and BS2 is located on the optical path of the pulsed laser beam output from the PO beam steering unit 40.

[0036] Each halving window HW1, HW2 is disposed between the final concave mirror CM18, CM24 in each loop optical path LP1, LP2 and the beam splitter BS1, BS2.

[0037] 2.2 Operation The pulsed laser light output from PO30 passes through an aperture OP1 and enters a beam splitter BS1, where a portion of the light is transmitted and the remaining portion is reflected. The pulsed laser light reflected by the beam splitter BS1 propagates through a loop optical path LP1 and passes through a halfing window HW1, where it is precisely combined with the pulsed laser light transmitted through the beam splitter BS1 and output.

[0038] A portion of the pulsed laser light that reenters the beam splitter BS1 is transmitted and the remaining portion is reflected. The pulsed laser light reflected here is combined with the pulsed laser light that passes through the beam splitter BS1 without passing through the loop optical path LP1. In this way, the pulsed laser light that passes through the beam splitter BS1 is successively superimposed on the pulsed laser light that passes through the loop optical path LP1, thereby expanding the pulse width. The pulsed laser light that passes through the loop optical path LP1 does not deviate from its optical path each time it propagates through the loop optical path LP1 by passing through the halving window HW1.

[0039] Similarly, the pulsed laser light output from the first OPS module 510 is incident on the beam splitter BS2, and the pulse width is further expanded while propagating through the loop optical path LP2.

[0040] 2.3 Actions and Effects 2, the pulse width can be significantly extended by the first-stage loop optical path LP1 and the second-stage loop optical path LP2, and the occurrence of speckles can be suppressed. In addition, since the pulse width is extended, the energy value per unit time irradiated to the optical system at the subsequent stage is reduced, and deterioration of the optical system is suppressed.

[0041] 3. Beam splitter sliding mechanism 3.1 Configuration 3 and 4 are schematic diagrams showing a sliding mechanism of a beam splitter. Fig. 3 is a view seen from a direction (Z direction) parallel to the optical path axis of the laser light passing through the beam splitter 150. Fig. 4 is a partial cross-sectional view taken along line 4-4 in Fig. 3. The H direction is parallel to the optical surface 151 of the beam splitter 150.

[0042] The slide mechanism 200 includes a BS holder 210 that holds a beam splitter (BS) 150, plates 212, 213, and 214, and plate holders 220a and 220b. The beam splitter 150 may be the beam splitter 53 shown in FIG. 1 or the beam splitters BS1 and BS2 shown in FIG.

[0043] The beam splitter 150 is fixed to the BS holder 210. The beam splitter 150 is disposed in a state in which an optical surface 151 onto which the laser beam is incident is inclined at 45 degrees with respect to the optical path axis of the pulsed laser beam output from the PO beam steering unit 40.

[0044] The BS holder 210 is fixed to the plate 212 using BS holder fixing screws 211a and 211b provided on the side of the BS holder 210. The axial centers of the BS holder fixing screws 211a and 211b are 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. In this way, the BS holder 210 is connected to the plate 214.

[0045] Plate 214 has a V-direction reference surface 232V and a Z-direction reference surface 232Z. V-direction reference surface 232V is perpendicular to the V direction and is a surface that defines a reference position of beam splitter 150 in the V direction. Z-direction reference surface 232Z is ​​perpendicular to the Z direction and is a surface that defines a reference position of beam splitter 150 in the Z direction. Plate 214 is an example of a "slide plate" in this disclosure.

[0046] Fig. 5 is a diagram showing a state in which beam splitter 150 is placed at a first position by slide mechanism 200. Fig. 6 is a diagram showing a state in which beam splitter 150 is placed at a second position by slide mechanism 200. Fig. 7 is a partial cross-sectional view taken along line 7-7 in Fig. 5.

[0047] Plate holders 220a, 220b are fixed to case 300 using bolts 222a, 222b, and plate 214 is brought into contact with reference surfaces 310V, 310Z on the case 300 side to hold plate 214 slidably along reference surfaces 310V, 310Z. Reference surface 310V is a case reference surface perpendicular to the V direction. Reference surface 310Z is a case reference surface perpendicular to the Z direction.

[0048] Case 300 may be case CS1 or case CS2 shown in Fig. 2. Furthermore, reference surface 310V and reference surface 310Z may be formed on base plate BP1 or base plate BP2 shown in Fig. 2. Plate 214 is pressed by the reaction force of springs (not shown) arranged on plungers 224, 225, 226, etc. so that V-direction reference surface 232V and Z-direction reference surface 232Z of plate 214 are reliably brought into contact with reference surface 310V and reference surface 310Z on the case 300 side.

[0049] A plunger 224 acting in the Z direction is attached to the plate holder 220a. A plunger 225 acting in the Z direction and a plunger 226 acting in the V direction are attached to the plate holder 220b.

[0050] 7 (-Z direction), pressing Z-direction reference surface 232Z (see FIG. 4) of plate 214 against reference surface 310Z on the case 300 side. Plunger 226 presses plate 214 in a direction (-V direction) from top to bottom in FIG. 7 (-V direction), pressing V-direction reference surface 232V (see FIG. 4) of plate 214 against reference surface 310V on the case 300 side.

[0051] Due to the reaction forces of plungers 224, 225, 226, V-direction reference surface 232V and Z-direction reference surface 232Z come into contact with reference surface 310V and reference surface 310Z on the case 300 side, respectively, and plate 214 is slidable along reference surface 310V and reference surface 310Z. That is, plate 214 is slidable in the ±H directions while maintaining its positions in the V and Z directions. The ±H directions may be referred to as the sliding direction.

[0052] 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 outside the case 300 to move the plate 214 in the sliding direction. The rod 250 extends to the outside of the case 300 by passing through a through hole 320 formed in the case 300. A sealing O-ring 322 that maintains airtightness inside the case 300 is disposed in the through hole 320, and the rod 250 is movable in the sliding direction in contact with the O-ring 322. A handle 252 is provided on the end of the rod 250 that extends to the outside of the case 300.

[0053] In addition, the handle 252 is formed with positioning grooves 254a, 254b that determine the position in the sliding direction. In this embodiment, an example is shown in which there are two positioning grooves 254a, 254b corresponding to two positions, the first position (FIG. 5) and the second position (FIG. 6), but there may be a positioning groove corresponding to each of three or more positions. The positioning groove 254a is an example of a "first recess" in this disclosure, the positioning groove 254b is an example of a "second recess" in this disclosure, and the positioning grooves 254a, 254b are examples of "multiple recesses" in this disclosure.

[0054] A plunger 326 used for positioning in the sliding direction is disposed in the case 300. The plunger 326 is fixed to a support member 328 that extends from the case 300. The plunger 326 regulates the position of the plate 214 in the sliding direction and performs positioning by engaging with any one of the positioning grooves 254a and 254b. The plunger 326 is an example of a "positioning plunger" in this disclosure. The positioning mechanism including the positioning grooves 254a and 254b and the plunger 326 is an example of a "positioning mechanism" in this disclosure. The handle 252 having the positioning grooves 254a and 254b is an example of an "engaged member" in this disclosure.

[0055] 3.2 Operation Plate 214 slides in a direction perpendicular to the optical path axis (Z-axis) and parallel to optical surface 151 of beam splitter 150, thereby shifting the laser irradiation location on beam splitter 150 while maintaining the orientation of optical surface 151. The direction parallel to optical surface 151 of beam splitter 150 may be a direction intersecting a maintenance surface of a housing (not shown) of laser device 2, or may be a direction passing through a maintenance opening provided in the maintenance surface. The maintenance surface is a surface perpendicular to the H direction.

[0056] As shown in FIG. 5, by engaging the plunger 326 with the positioning groove 254a of the handle 252, the plate 214 and the beam splitter 150 which is slidable integrally with the plate 214 are positioned at a first position.

[0057] Also, from the state shown in Figure 5, a field engineer or the like operates the handle 252 to pull out the rod 250, and as shown in Figure 6, the plate 214 and the beam splitter 150 are positioned in the second position by engaging the plunger 326 with the positioning groove 254b of the handle 252.

[0058] It is preferable to set the amount of movement (slide amount) in the sliding direction by the slide mechanism 200 so that the laser light irradiation area LA1 of the beam splitter 150 in the first position and the laser light irradiation area LA2 of the beam splitter 150 in the second position do not overlap.

[0059] For example, the laser device 2 is initially used in a first position, and when the optical characteristics of a portion of the beam splitter 150 deteriorate due to laser irradiation of the beam splitter 150, the beam splitter 150 is moved to a second position so that the laser light is irradiated onto other areas that are not deteriorated.

[0060] 3.3 Actions and Effects The beam splitter 150 deteriorates (energy transmittance deteriorates) due to laser irradiation. With the slide mechanism 200, the beam splitter 150 can be moved to shift the laser irradiation position on the beam splitter 150, and the laser light can be irradiated to a position that is not deteriorated. In this way, by using the beam splitter 150 while avoiding the deteriorated position, the frequency of replacement can be reduced, and the beam splitter 150 can be expected to have a long life. The number of times of sliding to shift the laser irradiation position depends on the size of the beam splitter 150 and the size of the laser irradiation area, but is typically about 2 to 5 times.

[0061] A change in the element arrangement angle of the beam splitter 150 has a small effect on the emitted light, and realignment by sliding only the beam splitter 150 is not necessary.

[0062] As a result, even if the beam splitter 150 is partially deteriorated, there is no need to replace the OPS module, and the module usage time can be extended several times, thereby reducing running costs.

[0063] Furthermore, the slide mechanism 200 allows the beam splitter 150 to slide while keeping the inside of the case 300 sealed, making it possible to reduce downtime associated with maintenance work.

[0064] 4. Challenges FIG. 8 is a diagram for explaining the problem of the slide mechanism, and is a partial cross-sectional view similar to FIG. 7. When fixing the BS holder 210 to the plate 212, the BS holder fixing screws 211a and 211b on the side of the BS holder 210 are tightened with a specified torque. As shown in FIG. 8, when torque is applied to the BS holder fixing screws 211a and 211b in the clockwise direction, which is the tightening direction, a force acts on the plate 214 in a direction away from the case 300, with the case 300 as a fulcrum, and the plunger 225 may contract due to this 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 case 300 side.

[0065] When such a gap occurs, the beam splitter 150 is no longer held at a predetermined position and angle with respect to the reference surface 310Z, which makes it difficult to adjust and check the optical axis while applying torque to the BS holder fixing screws 211a and 211b.

[0066] Therefore, an object of the present invention is to suppress the angle deviation of the beam splitter 150 even when a rotational force is applied to the plate 214, such as when the BS holder 210 is replaced.

[0067] 5. Embodiment 1 5.1 Configuration 9 and 10 are schematic diagrams showing a sliding mechanism of the beam splitter according to embodiment 1. Fig. 9 is a diagram seen from a direction (Z direction) parallel to the optical path axis of the laser light transmitted through the beam splitter 150, and Fig. 10 is a partial cross-sectional view taken along line 10-10 in Fig. 9.

[0068] Case 300 has non-through tapped hole 301 with a female thread formed on the inner circumference on reference surface 310Z with which plate 214 comes into contact. The position of tapped hole 301 in the V direction is a position between the hole in case 300 into which bolt 222a is inserted and the hole in case 300 into which bolt 222b is inserted. The position of tapped hole 301 in the H direction is the same as the hole in case 300 into which bolt 222a is inserted and the hole in case 300 into which bolt 222b is inserted. Tapped hole 301 is an example of a "screw hole" in this disclosure.

[0069] Plate 214 has through hole 215B at a position corresponding to tapped hole 301. Through hole 215B penetrates in the Z direction from the surface to which plate 213 is fixed to Z direction reference surface 232Z (see FIG. 4). Through hole 215B is a non-threaded hole with no female thread formed on the inner circumference, and has a larger diameter than tapped hole 301. In the example of FIG. 9, the position corresponding to tapped hole 301 refers to a position where through hole 215B and tapped hole 301 are coaxial when beam splitter 150 is placed at the second position. Through hole 215B is an example of a "through hole" in this disclosure.

[0070] 9, case 300 is provided with two tapped holes 301, and plate 214 is provided with two through holes 215B corresponding to the two tapped holes 301. In this manner, a plurality of pairs of tapped holes 301 and through holes 215B may be arranged.

[0071] Furthermore, plate 214 may have through hole 215A at a position corresponding to tapped hole 301 when beam splitter 150 is placed at the first position. Through hole 215A penetrates in the Z direction from the surface to which plate 213 is fixed to Z direction reference surface 232Z. Through hole 215A is a non-threaded hole that does not have a female thread formed on its inner periphery, and has a larger diameter than tapped hole 301.

[0072] The through hole provided in plate 214 may be a long hole extending in the H direction so as to be in a position corresponding to tapped hole 301 regardless of whether beam splitter 150 is positioned in any position from the first position to the second position.

[0073] 5.2 Operation Before applying torque to the BS holder fixing screws 211a, 211b, a field engineer or the like fixes the case 300 and the plate 214 so that no gap is created between the Z-direction reference surface 232Z of the plate 214 and the reference surface 310Z on the case 300 side even when torque is applied.

[0074] Fig. 11 is a diagram for explaining the fixing of case 300 and plate 214. As shown in Fig. 11, slide plate fixing screw 216 is fastened to tapped hole 301 via through hole 215B, thereby fixing case 300 and plate 214. Slide plate fixing screw 216 may be fastened to tapped hole 301 via through hole 215A.

[0075] 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 .

[0076] Finally, the field engineer or the like removes the slide plate fixing screw 216. This allows the beam splitter 150 to slide.

[0077] 5.3 Actions and Effects The configuration of the first embodiment reduces the angle deviation of the beam splitter 150, i.e., the optical axis deviation of the beam splitter 150, when torque is applied to the BS holder fixing screws 211a and 211b. This makes it easier to perform assembly adjustments and check the optical axis while applying torque.

[0078] 6. Embodiment 2 6.1 Configuration Fig. 12 is a schematic diagram showing a sliding mechanism of a beam splitter according to embodiment 2. The sliding mechanism 200B includes a plate 240 and a rod 260. Note that the beam splitter 150, the BS holder 210, the BS holder fixing screws 211a and 211b, the plate 212, and the plate 213 are not shown in Fig. 12.

[0079] Plate 240 is fixed to side surface 234, which is a surface parallel to the VZ plane of plate 214, with screws (not shown). Plate 240 has two standing portions 242A, 242B. Standing portion 242A has at its tip a hook portion 244A facing standing portion 242B. Standing portion 242B has at its tip a hook portion 244B facing standing portion 242A. Plate 240 is an example of a "plate portion" in this disclosure.

[0080] Rod 260 passes through through hole 320 formed in case 300. Handle 252 is provided at the end of rod 260 on the outer side of case 300. A circular flange portion 262 protruding radially outward of rod 260 is provided at the end of rod 260 on the inner side of case 300, and the tip of rod 260 has a T-shaped cross section.

[0081] The distance between the hooking portion 244A and the hooking 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 in the H direction of the erected portions 242A and 242B of the plate 240 is larger than the length in the H direction of the flange portion 262. The rod 260 penetrates between the hooking portion 244A and the hooking portion 244B of the plate 240, and the flange portion 262 is held with 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 state, and the slide shaft of the plate 214 is made into a single shaft. The hooking portion 244 and the flange portion 262 are an example of a "transmission member" in this disclosure.

[0082] 6.2 Operation 12 (direction H), flange portion 262 of rod 260 hooks onto hook portions 244A and 244B of plate 240, and plate 240 transmits the displacement of rod 260 in the direction H to plate 214. As a result, the field engineer can move plate 214 in the direction H.

[0083] 12 (-H direction), the flange portion 262 of the rod 260 comes into contact with 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.

[0084] Moreover, the transmission of displacement of the rod 260 in a direction different from the ±H direction to the plate 214 is restricted.

[0085] 6.3 Actions and Effects By floating 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 a direction different from the sliding direction of the rod 260 is not transmitted. As a result, the sliding axis becomes one axis of the reference surface 310V. Therefore, it is possible to absorb the misalignment and the deviation angle between the rod 260 and the reference surface 310V on the case 300 side. This is expected to improve the push-pull operability such as light operability, and to further reduce the angle deviation of the beam splitter when pushing and pulling.

[0086] 7. Embodiment 3 7.1 Configuration Fig. 13 is a schematic diagram showing a sliding mechanism of the beam splitter according to the third embodiment, and is a cross-sectional view taken along line 13-13 in Fig. 12. Note that Fig. 13 shows only the periphery of both ends of the plate 214.

[0087] As shown in FIG. 13, in the slide mechanism 200C, both ends in the sliding direction of a Z-direction reference surface 232Z, which is a contact surface with the case 300, of a plate 214 are chamfered at 30 degrees with a curvature radius of R5.

[0088] That is, the plate 214 has inclined surfaces 232C at both ends in the sliding direction of the Z-direction reference surface 232Z. The inclined surfaces 232C are surfaces inclined with respect to the sliding direction, and connect 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 desirably equal to or greater than 10 degrees and equal to or less than 45 degrees.

[0089] The plate 214 also includes a curved surface 232R having a radius of curvature between the Z-direction reference surface 232Z and the inclined surface 232C. The radius of curvature of the curved surface 232R is 5 millimeters. The radius of curvature of the curved surface 232R is preferably 3 millimeters or more and 15 millimeters or less.

[0090] Furthermore, the material of the plate 214 may be SUS440C, which has a relatively high hardness. In this manner, the Z-direction reference surface 232Z and the V-direction reference surface 232V pressed by the plungers 224, 225, and 226 may be made of a hard material, such as stainless steel. Furthermore, the plate 214 may be hardened or coated.

[0091] 7.2 Actions and Effects According to the slide mechanism 200C, the inclined surface 232C and the curved surface 232R reduce the pushing / pulling resistance in the sliding direction, so that vibration during pushing / pulling can be suppressed. Therefore, it is expected that the angle deviation of the beam splitter 150 during pushing / pulling can be further reduced.

[0092] Furthermore, with the slide mechanism 200C, the hardness is increased by changing the material, which reduces the impression caused by the ball plunger and suppresses contamination of the surface of the beam splitter 150 due to dust generation.

[0093] 8. Manufacturing method of electronic devices 14 is a diagram showing a schematic configuration example of an exposure apparatus 800. The exposure apparatus 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 apparatus 800. The illumination optical system 806 illuminates a reticle pattern of a reticle (not shown) arranged on a reticle stage RT with the laser light incident from the laser device 2. The projection optical system 808 reduces and projects the laser light transmitted through the reticle to form an image on a workpiece (not shown) arranged on a workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with photoresist.

[0094] Exposure apparatus 800 exposes a workpiece to laser light reflecting a reticle pattern by synchronously translating reticle stage RT and workpiece table WT. After transferring the reticle pattern to a semiconductor wafer by the exposure process described above, a semiconductor device can be manufactured through multiple processes. A semiconductor device is an example of an "electronic device" in this disclosure.

[0095] 9.Other The above description is intended to be illustrative rather than restrictive. Thus, it will be apparent to those skilled in the art that modifications may be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to those skilled in the art that the disclosed embodiments may be used in combination.

[0096] Terms used throughout the present specification and claims should be interpreted as "open ended" terms unless otherwise specified. For example, terms such as "include," "have," "comprise," and "include" should be interpreted as "not excluding the presence of elements other than those listed." In addition, the modifier "a" should be interpreted as "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 include combinations of these with elements other than "A," "B," and "C."

Claims

1. a beam splitter that separates the laser light incident on the optical surface into a reflected laser light and a transmitted laser light; a holder that fixes the beam splitter with an optical surface of the beam splitter tilted with respect to an optical path axis of the incident laser light; a plurality of mirrors that direct the reflected laser light to the beam splitter; a slide mechanism that moves the beam splitter in a direction parallel to the optical surface; Equipped with The slide mechanism includes: a slide plate to which the holder is connected; a case that holds the slide plate so as to be movable in a sliding direction relative to a base plate on which the plurality of mirrors are arranged; Equipped with The case has a screw hole with a female screw formed on an inner periphery, The slide plate has through holes at positions corresponding to the screw holes. Optical pulse stretcher.

2. 2. An optical pulse stretcher according to claim 1, the case has a plurality of the screw holes, The slide plate includes a plurality of through holes respectively corresponding to the plurality of screw holes. Optical pulse stretcher.

3. 2. An optical pulse stretcher according to claim 1, the case includes a first screw hole corresponding to a first position of the slide plate, and a second screw hole corresponding to a second position of the slide plate moved from the first position; Optical pulse stretcher.

4. 4. The optical pulse stretcher of claim 3, further comprising: a positioning mechanism that regulates the position of the slide plate in the sliding direction, The positioning mechanism includes: an engaged member having a plurality of recesses including a first recess for disposing the slide plate at a first position in the sliding direction and a second recess for disposing the slide plate at a second position in the sliding direction; a positioning plunger that engages with any one of the plurality of recesses; Optical pulse stretcher.

5. 2. An optical pulse stretcher according to claim 1, The slide plate has an oblong through hole extending in the sliding direction. Optical pulse stretcher.

6. 2. An optical pulse stretcher according to claim 1, a holder fixing screw for connecting the holder to the slide plate; Optical pulse stretcher.

7. 7. An optical pulse stretcher according to claim 6, comprising: the axis of the holder fixing screw is parallel to the optical surface; Optical pulse stretcher.

8. 8. An optical pulse stretcher according to claim 7, comprising: a plunger that biases the slide plate against the case, a force is applied to the slide plate in a direction away from the case by fastening the holder fixing screw; The force in the direction away from the case is greater than the force that the plunger applies to the case. Optical pulse stretcher.

9. 2. An optical pulse stretcher according to claim 1, The through hole is a non-threaded hole having no female thread formed on the inner periphery. Optical pulse stretcher.

10. 2. An optical pulse stretcher according to claim 1, a slide plate fixing screw that is fastened to the screw hole through the through hole, Optical pulse stretcher.

11. 2. An optical pulse stretcher according to claim 1, A rod movable in the sliding direction; a transmission member that transmits the displacement of the rod to the slide plate; Equipped with The transmission member transmits a displacement of the rod in the sliding direction and restricts transmission of a displacement in a direction different from the sliding direction of the rod. Optical pulse stretcher.

12. 12. An optical pulse stretcher according to claim 11, comprising: The transmission member is A plate portion provided on the slide plate; A flange portion provided on the rod; Equipped with As the rod moves, the flange portion comes into contact with the slide plate or the plate portion to transmit the displacement of the rod in the sliding direction to the slide plate. Optical pulse stretcher.

13. 2. An optical pulse stretcher according to claim 1, The slide plate is A contact surface that contacts the case; A side surface of the slide plate in the sliding direction; an inclined surface inclined with respect to the sliding direction and connecting the contact surface and the side surface; Equipped with Optical pulse stretcher.

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

15. 14. An optical pulse stretcher according to claim 13, comprising: The slide plate includes a curved surface having a radius of curvature between the contact surface and the inclined surface. Optical pulse stretcher.

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

17. 2. An optical pulse stretcher according to claim 1, The material of the slide plate is stainless steel. Optical pulse stretcher.

18. 20. An optical pulse stretcher according to claim 17, comprising: The stainless steel is SUS440C. Optical pulse stretcher.

19. A pair of electrodes for generating a discharge; an optical pulse stretcher that stretches the pulse width of the pulsed laser light generated by the discharge generated between the electrodes; Equipped with The optical pulse stretcher comprises: a beam splitter that separates the laser light incident on the optical surface into a reflected laser light and a transmitted laser light; a holder that fixes the beam splitter with an optical surface of the beam splitter tilted with respect to an optical path axis of the incident laser light; a plurality of mirrors that direct the reflected laser light to the beam splitter; a slide mechanism that moves the beam splitter in a direction parallel to the optical surface; Equipped with The slide mechanism includes: a slide plate to which the holder is connected; a case that movably holds the slide plate relative to a base plate on which the plurality of mirrors are disposed; Equipped with The case has a screw hole, The slide plate has through holes at positions corresponding to the screw holes. Laser device.

20. 1. A method for manufacturing an electronic device, comprising: A pair of electrodes for generating a discharge; an optical pulse stretcher that stretches the pulse width of the pulsed laser light generated by the discharge generated between the electrodes; Equipped with The optical pulse stretcher comprises: a beam splitter that separates the laser light incident on the optical surface into a reflected laser light and a transmitted laser light; a holder that fixes the beam splitter with an optical surface of the beam splitter tilted with respect to an optical path axis of the incident laser light; a plurality of mirrors that direct the reflected laser light to the beam splitter; a slide mechanism that moves the beam splitter in a direction parallel to the optical surface; Equipped with The slide mechanism includes: a slide plate to which the holder is connected; a case that movably holds the slide plate relative to a base plate on which the plurality of mirrors are disposed; Equipped with The case has a screw hole, The slide plate has through holes at positions corresponding to the screw holes. generating a laser beam having an expanded pulse width by a laser device; outputting the laser light to an exposure device; A method for manufacturing an electronic device, comprising exposing a photosensitive substrate to the laser light in the exposure apparatus to manufacture an electronic device.

Images