Laser device and method for manufacturing electronic device

Abstract

A laser device is provided with: a pair of electrodes for generating discharge; and an optical pulse spreading device that spreads the pulse width of the pulsed laser light generated by the discharge generated between the electrodes, the optical pulse spreading device being provided with: a beam splitter in which the optical surface on which the pulsed laser light is incident is arranged so as to be inclined with respect to the optical path axis of the pulsed laser light; pulse laser incident to the optical surface is separated into reflected laser and transmitted laser; a plurality of reflectors that guide the reflected laser light to the beam splitter; and a slide mechanism that moves the beam splitter in a direction perpendicular to the discharge direction and parallel to the optical surface.

Description

Technical Field

[0001] The present disclosure relates to 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 the 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 as wide as 350pm to 400pm. Therefore, if the projection lens is made of a material that transmits ultraviolet rays such as KrF and ArF lasers, chromatic aberration may 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 chromatic aberration can be ignored. Therefore, in order to narrow the spectral line width, a narrowing module (Line Narrowing Module: LNM) containing 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: U.S. Patent No. 10585215

[0007] Patent Document 2: U.S. Patent Application Publication No. 2018 / 0019141

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 10-144987

[0009] Patent Document 4: U.S. Patent No. 7415056 Summary of the invention

[0010] A laser device according to one aspect of the present disclosure comprises: a pair of electrodes that generate discharge; and an optical pulse stretcher that expands the pulse width of a pulse laser generated by the discharge generated between the electrodes, the optical pulse stretcher comprising: a beam splitter, wherein an optical surface for incident pulse laser light is arranged obliquely relative to an optical path axis of the pulse laser light, and the pulse laser light incident on the optical surface is separated into reflected laser light and transmitted laser light; a plurality of mirrors that guide the reflected laser light toward the beam splitter; and a sliding mechanism that moves the beam splitter in a direction perpendicular to the direction of discharge and parallel to the optical surface.

[0011] Another aspect of the present disclosure relates to a method for manufacturing an electronic device, which includes the following steps: generating a laser with an expanded pulse width by a laser device; outputting the laser to an exposure device; and exposing the laser to a photosensitive substrate in the exposure device to manufacture an electronic device, wherein the laser device comprises: a pair of electrodes that generate discharge; and an optical pulse stretcher that expands the pulse width of a pulsed laser generated by the discharge generated between the electrodes, the optical pulse stretcher comprising: a beam splitter, wherein an optical surface for incident pulsed laser is arranged to be inclined relative to an optical path axis of the pulsed laser, and the pulsed laser incident on the optical surface is separated into reflected laser and transmitted laser; a plurality of mirrors that guide the reflected laser to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction perpendicular to the direction of discharge and parallel to the optical surface. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0013] Figure 1 The structure of an exemplary laser device is schematically shown.

[0014] Figure 2 This is a perspective view showing another example of an optical pulse stretcher (OPS).

[0015] Figure 3 This is a perspective view showing a state where the maintenance panel of the housing of the laser device is opened.

[0016] Figure 4 The main part of the sliding mechanism of the beam splitter of the OPS applied to the laser device according to the first embodiment is schematically shown.

[0017] Figure 5 Yes Figure 4 A side view, partially in section, of a sliding mechanism is shown.

[0018] Figure 6 This is a diagram showing a state where the beam splitter is arranged at the first position by the sliding mechanism.

[0019] Figure 7It is a diagram showing a state where the beam splitter is arranged at the second position by the sliding mechanism.

[0020] Figure 8 yes Figure 7 Cross-sectional view at line 8-8 in FIG.

[0021] Fig. 9 The main part of the sliding mechanism of the beam splitter of the OPS applied to the laser device of the second embodiment is schematically shown.

[0022] Fig.10 Yes Fig. 9 A side view, partially in section, of a sliding mechanism is shown.

[0023] Fig.11 This is a diagram showing a state where the beam splitter is arranged at the first position by the sliding mechanism.

[0024] Fig.12 It is a diagram showing a state where the beam splitter is arranged at the second position by the sliding mechanism.

[0025] Fig.13 yes Fig.12 A cross-sectional view taken along line 13-13 in FIG.

[0026] Fig.14 The main parts of the sliding mechanism of the OPS applied to the laser device of the third embodiment are schematically shown.

[0027] Fig.15 is a side view including a partial cross section of the sliding mechanism.

[0028] Fig.16 The main parts of the sliding mechanism of the OPS applied to the laser device of the fourth embodiment are schematically shown.

[0029] Fig.17 Yes Fig.16 A side view, partially in section, of a sliding mechanism is shown.

[0030] Fig.18 This is a perspective view schematically showing the structure of an OPS applied to the laser device according to the fifth embodiment.

[0031] Fig.19 This is an explanatory diagram of a calculation formula for obtaining the amount of deviation of light rays caused by a transmission element.

[0032] Fig. 20 A configuration example of an exposure device is schematically shown. DETAILED DESCRIPTION

[0033] - Contents - 1. Overview of laser device

[0034] 1.1 Structure

[0035] 1.2 Action

[0036] 2.Other examples of OPS

[0037] 2.1 Structure

[0038] 2.2 Action

[0039] 2.3 Function and effect

[0040] 3.Topic

[0041] 4. Implementation Method 1

[0042] 4.1 Structure

[0043] 4.2 Action

[0044] 4.3 Function and effect

[0045] 5. Implementation Method 2

[0046] 5.1 Structure

[0047] 5.2 Action

[0048] 5.3 Function and effect

[0049] 6. Implementation Method 3

[0050] 6.1 Structure

[0051] 6.2 Action

[0052] 6.3 Function and effect

[0053] 6.4 Variations

[0054] 7. Implementation Method 4

[0055] 7.1 Structure

[0056] 7.2 Action

[0057] 7.3 Function and effect

[0058] 7.4 Variations

[0059] 8. Implementation Method 5

[0060] 8.1 Structure

[0061] 8.2 Action

[0062] 8.3 Function and effect

[0063] 8.4 Modification 1

[0064] 8.5 Modification 2

[0065] 9. Modification of Laser Device

[0066] 10. On the manufacturing method of electronic devices

[0067] 11. Others

[0068] 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, all of the structures and actions described in each embodiment are not necessarily required as the structures and actions of the present disclosure. In addition, the same reference numerals are marked on the same components, and repeated descriptions are omitted.

[0069] 1. Overview of laser equipment

[0070] 1.1 Structure

[0071] Figure 1 The structure of the exemplary laser device 2 is schematically shown. 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 .

[0072] 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 by Littrow to make the incident angle and the diffraction angle consistent.

[0073] 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%.

[0074] 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.

[0075] The MO beam steering unit 20 includes a high reflection mirror 21 and a high reflection mirror 22 , and is configured so that the pulse laser output from the MO 10 is incident on the PO 30 .

[0076] 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.

[0077] 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%.

[0078] 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 so that the pulse laser output from the PO 30 is incident on the OPS 50.

[0079] The 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 transmits a part of the incident pulse laser and reflects the other pulse laser. That is, the beam splitter 53 separates the incident pulse laser into reflected laser and transmitted laser. The reflectivity of the beam splitter 53 can be 60%, for example. The beam splitter 53 allows the pulse laser transmitted through the beam splitter 53 to be output from the laser device 2.

[0080] The four concave mirrors 54a to 54d constitute a delayed optical path of the pulsed laser beam reflected by the first surface of the beam splitter 53. The pulsed laser beam reflected by the first surface of the beam splitter 53 is reflected by the four concave mirrors 54a to 54d and is imaged by the beam splitter 53 again.

[0081] 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.

[0082] 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 forms an image on the first surface of the beam splitter 53 at the same magnification (1:1) as a first image.

[0083] The concave mirror 54C and the concave mirror 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. Moreover, 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 mirror 54C and the concave mirror 54d are configured so that the first image is imaged as the second image on the second surface of the beam splitter 53 in a 1:1 ratio. The four concave mirrors 54a to 54d are an example of the "plurality of reflection mirrors" in the present disclosure.

[0084] 1.2 Action

[0085] 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 composed of 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.

[0086] In synchronization with the timing at which 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.

[0087] The pulse laser that has passed through the OPS50 can be incident on the beam characteristic measurement device through a monitoring module (not shown). The monitoring module is a module that measures pulse energy, spectral line width, wavelength, etc. The beam characteristic measurement device is a module that measures pointing, divergence, polarization, etc. Figure 1 , an example of a one-stage OPS 50 is shown, 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.

[0088] 2.Other examples of OPS

[0089] 2.1 Structure

[0090] Figure 2 It is a perspective view showing another example of OPS. Figure 2 The two-stage OPS51 shown in the figure is used to replace Figure 1 OPS50 described in.

[0091] OPS51 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 housing CS1 including a base plate BP1. The loop optical path LP1 is a delay optical path formed by concave mirrors CM11-CM18 and a half window HW1.

[0092] The second OPS module 520 includes a beam splitter BS2, a loop optical path LP2 and a housing CS2 including a base plate BP2. The loop optical path LP2 is a delay optical path formed by concave mirrors CM21-CM24 and a half window HW2.

[0093] 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 can constitute any surface of each housing CS1, CS2, but Figure 2 In the example shown, a surface parallel to the HV plane on 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.

[0094] It should be noted that, in this specification, the terms "orthogonal" or "perpendicular" are not limited to the strictly orthogonal or perpendicular situations, unless explicitly stated, and include the concept of approximately orthogonal or approximately perpendicular, including the range of angle differences that are practically permissible without losing the technical significance. In addition, in this specification, the term "parallel", unless explicitly stated, is not limited to the strictly parallel situation, and includes the concept of approximately parallel, including the range of angle differences that are practically permissible without losing the technical significance.

[0095] The housing CS1 is formed with openings OP1 and OP2 for passing laser light. The opening OP1 is an entrance of the laser light to the first OPS module 510, and the opening OP2 is an exit of the laser light from the first OPS module 510. Similarly, the housing CS2 is formed with an opening OP3 as an entrance of the laser light and an opening OP4 as an exit.

[0096] Each concave mirror CM11 to CM18, CM21 to CM24 is arranged at both ends of the housing 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 across the beam splitter BS1.

[0097] Similarly, concave mirrors CM15, CM13 and CM17 are arranged to face concave mirrors CM14, CM16 and CM12. The loop optical path LP1 is configured 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.

[0098] 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 loop 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.

[0099] 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 .

[0100] Each pair of half windows HW1, HW2 is arranged between the last concave mirror CM18, CM24 and the beam splitter BS1, BS2 in each loop optical path LP1, LP2.

[0101] 2.2 Action

[0102] The pulse laser output from PO30 enters the beam splitter BS1 through the opening OP1, partially transmits and the remaining part is reflected. The pulse laser reflected by the beam splitter BS1 propagates in the loop optical path LP1, passes through the half window HW1, and is combined with the pulse laser transmitted through the beam splitter BS1 with high precision and output.

[0103] A portion of the pulse laser light incident on the beam splitter BS1 again is transmitted and the remaining portion is reflected. The pulse laser light reflected here is combined with the pulse laser light transmitted through the beam splitter BS1 without passing through the loop optical path LP1. In this way, the pulse laser light passing through the loop optical path LP1 is sequentially overlapped on the pulse laser light transmitted through the beam splitter BS1, thereby expanding the pulse width. The pulse laser light passing through the loop optical path LP1 passes through the half window HW1, so that the optical path does not deviate each time it propagates in the loop optical path LP1.

[0104] Similarly, 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 the process of propagating in the loop optical path LP2.

[0105] 2.3 Function and effect

[0106] according to Figure 2 The OPS51 shown can greatly expand the pulse width through the first-stage loop optical path LP1 and the second-stage loop optical 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, thereby suppressing the degradation of the optical system.

[0107] 3.Topic

[0108] As the output of the laser device 2 increases, degradation of optical characteristics is sometimes observed in the beam splitters 53, BS1, and BS2 that have been used for a long time. Deterioration of optical characteristics is typically a decrease in the transmittance of the laser transmission portion or a decrease in the reflectance of the laser reflection portion. In such a case, the transmittance of the entire OPS 50 and 51 decreases, or the pulse waveform after passing through the OPS 50 and 51 changes.

[0109] In the case of the laser device 2 of the comparative example, in order to restore the transmittance, the beam splitter 53, BS1, BS2, etc. whose optical characteristics have deteriorated need to be replaced. In addition, the comparative examples disclosed in the present disclosure are methods that the applicant recognizes are known only to the applicant, and are not known examples that the applicant himself considers.

[0110] like Figure 3 As shown, the housing 4 of the laser device 2 is provided with an openable and closable maintenance panel 5. In the laser device 2, in order to replace only the optical elements such as the beam splitter 53, BS1, and BS2, it is necessary to remove the maintenance panel 5 of the housing 4 of the laser device 2, and then access the optical element holders inside the first OPS module 510 and / or the second OPS module 520, but the opening 7 (maintenance opening) of the maintenance surface 6 is limited, the workability is poor, and it is difficult to implement.

[0111] As a current maintenance operation, the first OPS module 510 and the second OPS module 520 are removed from the laser device 2 as a set at the site (customer) where the laser device 2 is configured, and the optical axis is adjusted after being replaced with a new set. In addition, the OPS set removed from the laser device 2 is returned to the manufacturing plant of the laser device 2 to replace the internal deteriorated optical elements and adjust the optical axis of the OPS unit. Therefore, there are the following issues.

[0112] [Issue 1] The laser at the customer's site was down for a very long time in order to replace the OPS set.

[0113] [Issue 2] Increased man-hours and / or costs associated with transporting OPS sets between customers and factories.

[0114] [Problem 3] Optical components such as the beam splitter 53, BS1, and BS2 are disposable and therefore expensive.

[0115] 4. Implementation Method 1

[0116] 4.1 Structure

[0117] Figure 4 and Figure 5 The slide mechanism 200 of the beam splitter 150 of the OPS applied to the laser device 2 according to the first embodiment is schematically shown. Figure 4 This is a diagram observed from a direction (Z direction) parallel to the optical path axis of the laser light transmitted through the beam splitter 150. Figure 5 It is a side view including a partial cross section viewed from a direction (H direction) perpendicular to the Z direction and the V direction. In addition, the H direction is a direction parallel to the optical surface 151 of the beam splitter 150 .

[0118] The slide mechanism 200 includes a beam splitter (BS) holder 210 that holds the BS 150, plates 211, 212, 213, and plate holders 220a, 220b. The beam splitter 150 may be Figure 1 The beam splitter 53 shown or Figure 2 Either of the beam splitters BS1, BS2 shown.

[0119] 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.

[0120] The BS holder 210 is fixed to the plate 211. The plate 211 is fixed to the plate 212. The plate 212 is fixed to the plate 213. The plate 213 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 for defining 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 for defining the Z-direction reference position of the beam splitter 150.

[0121] Figure 6 This is a diagram showing a state where the beam splitter 150 is arranged at the first position by the slide mechanism 200 . Figure 7 This is a diagram showing a state where the beam splitter 150 is arranged at the second position by the slide mechanism 200 . Figure 8 yes Figure 7 Cross-sectional view at line 8-8 in FIG.

[0122] The plate frames 220a and 220b are fixed to the housing 300 using bolts 222a and 222b so that the plate 213 contacts the reference surfaces 310V and 310Z on the housing 300 side (see Figure 8 ), the plate 213 is held to be able to slide along the reference planes 310V and 310Z. The reference plane 310V is a shell reference plane perpendicular to the V direction. The reference plane 310Z is a shell reference plane perpendicular to the Z direction.

[0123] 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 2In order to make the V-direction reference surface 232V and the Z-direction reference surface 232Z of the plate 213 reliably contact the reference surface 310V and the reference surface 310Z on the housing 300 side, the plate 213 is pressed by the reaction force of the spring (not shown) arranged on the plunger 224, 225, 226, etc.

[0124] 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.

[0125] Plunger 224, 225 Figure 5 The plate 213 is pressed in the direction (-Z direction) from right to left, and the Z direction reference surface 232Z of the plate 213 is pressed against the reference surface 310Z on the housing 300 side. Figure 5 The plate 213 is pressed in a direction (−V direction) from the top to the bottom, and the V-direction reference surface 232V of the plate 213 is pressed against the reference surface 310V on the shell 300 side.

[0126] Through the reaction force of the plungers 224, 225, and 226, the plate 213 is able to slide along the reference plane 310V and the reference plane 310Z on the side of the housing 300, respectively, with the V-direction reference plane 232V and the Z-direction reference plane 232Z. That is, the plate 213 can slide along the H direction while maintaining the position in the V direction and the Z direction. The H direction is sometimes referred to as the sliding direction. The plate 213 is an example of a "movable plate" in the present disclosure. The reference plane 310Z is an example of a "first reference plane" in the present disclosure, and the reference plane 232V is an example of a "second reference plane" in the present disclosure. The plungers 224 and 225 are respectively examples of the "first plunger" in the present disclosure. The plunger 226 is an example of the "second plunger" in the present disclosure.

[0127] The plate 213 is connected to a rod 250 extending in the H direction so that a force can be applied to the plate 213 from the outside of the housing 300 to move the plate 213 in the H 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 is connected to the O-ring 322 and can move in the H direction. A handle 252 is provided at the end of the rod 250 extending to the outside of the housing 300. The O-ring 322 is an example of a "sealing member" in the present disclosure.

[0128] In addition, the handle 252 is formed with positioning grooves 254a and 254b for defining the position of the sliding direction. Figure 6 ) and the second position ( Figure 7) 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 three or more positions. The positioning grooves 254a and 254b are examples of the "first recess" and the "second recess" in the present disclosure.

[0129] 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 positions the H direction position of the plate 213, i.e., the H direction position of the beam splitter 150, by engaging with any one of the plurality of positioning grooves 254a, 254b. 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, 254b is an example of a "engaged member" in the present disclosure.

[0130] 4.2 Action

[0131] The plate 213 slides in a direction perpendicular to the optical path axis (Z axis) and parallel to the optical surface 151 of the beam splitter 150, thereby shifting the irradiation position of the laser to the beam splitter 150 while maintaining the orientation of the optical surface 151. The direction parallel to the optical surface 151 of the beam splitter 150 may be a direction intersecting the maintenance surface 6 or a direction passing through the maintenance opening 7.

[0132] like Figure 6 As shown, by engaging the plunger 326 with the positioning groove 254 a of the handle 252 , the plate 213 and the beam splitter 150 that slides integrally with the plate 213 can be positioned at the first position.

[0133] In addition, from Figure 6 From the state, the field engineer operates the handle 252 to pull out the rod 250, such as Figure 7 As shown, the plunger 326 is engaged with the positioning groove 254b of the handle 252, thereby positioning the plate 213 and the beam splitter 150 at the second position.

[0134] The movement amount (sliding amount) in the sliding direction by the sliding mechanism 200 is preferably set in advance so that the irradiation area LA1 of the beam splitter 150 at the first position does not overlap with the irradiation area LA2 of the beam splitter 150 at the second position.

[0135] 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.

[0136] 4.3 Function and effect

[0137] The beam splitter 150 deteriorates due to laser irradiation (energy transmittance deteriorates). According to the structure of Embodiment 1, by moving the beam splitter 150 using the sliding mechanism 200, the laser irradiation position of the beam splitter 150 can be shifted, and the laser can be irradiated to a non-degraded position. In this way, by avoiding the degraded position and using the beam splitter 150, the frequency of replacement can be reduced, and the life of the beam splitter 150 can be extended. 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.

[0138] The change in the arrangement angle of the elements of the beam splitter 150 has little influence on the emitted light, and realignment by simply sliding the beam splitter 150 is not necessary.

[0139] 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.

[0140] Furthermore, according to the configuration of the first embodiment, 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.

[0141] 5. Implementation Method 2

[0142] 5.1 Structure

[0143] Figures 9 to 13 FIG. 2 shows the structure of the slide mechanism 202 of the beam splitter 150 of the OPS applied to the laser device 2 of the second embodiment. Figures 9 to 13 The sliding mechanism 202 shown replaces Figure 4 to Figure 7 The sliding mechanism 200 of the first embodiment described in FIG. Figures 9 to 13 The pictures and Figures 4 to 8 The structure of the sliding mechanism 202 of the second embodiment will be described with respect to the differences from the sliding mechanism 200 of the first embodiment.

[0144] The slide mechanism 202 includes linear guides 270a and 270b instead of the plate frames 220a and 220b of the first embodiment (see Fig.13 ).

[0145] The linear guides 270a and 270b are positioned and arranged on the reference surface 310Z of the housing 300. The linear guides 270a and 270b are arranged parallel to the H direction. The plate 213 has a linear guide mounting surface 282Z and a linear guide mounting surface 282V (see Fig.10The linear guide mounting surface 282Z is ​​perpendicular to the Z direction and is a mounting surface engaged with the Z-direction mounting surfaces of the linear guides 270a and 270b. The linear guide mounting surface 282V is perpendicular to the V direction and is a mounting surface engaged with the V-direction mounting surfaces of the linear guides 270a and 270b.

[0146] The plate 213 is supported by the linear guides 270a and 270b so as to be able to slide freely in the H direction. The other structures may be the same as those in Embodiment 1. The linear guides 270a and 270b are examples of "positioning configuration components" in the present disclosure, and the Z-direction mounting surfaces and V-direction mounting surfaces of the linear guides 270a and 270b are examples of "reference surfaces of components" in the present disclosure.

[0147] 5.2 Action

[0148] The operation of the sliding mechanism 202 may be the same as that of the sliding mechanism 200 of the first embodiment (see Fig.11 , Fig.12 ).

[0149] 5.3 Function and effect

[0150] According to Embodiment 2, the linear guides 270 a and 270 b can be used to accurately position the beam splitter 150 in the V direction and the Z direction. In addition, the angular deviation between the optical surface 151 of the beam splitter 150 and the optical path axis can be suppressed during the sliding operation.

[0151] 6. Implementation Method 3

[0152] 6.1 Structure

[0153] Fig.14 This is a diagram schematically showing a main part of a slide mechanism 203 of an OPS applied to a laser device 2 according to Embodiment 3. The slide mechanism 203 is a structure capable of simultaneously moving two beam splitters BS1 and BS2 of a two-stage OPS module.

[0154] Fig.15 This is a side view including a partial cross section of the sliding mechanism 203 as viewed from the H direction. Fig.14 and Fig.15 The structure shown in the figure shows Figures 4 to 8 The difference between the sliding mechanism 200 described in FIG.

[0155] The slide mechanism 203 includes, in addition to the BS holder 210 that holds the beam splitter BS1 , a BS holder 282 that holds the beam splitter BS2 , a plate 284 that fixes the BS holder 282 , and a plate 285 that fixes the plate 284 to the plate 213 .

[0156] The beam splitter BS2 is arranged in a state where the optical surface 152 on which the laser beam is incident is inclined at 45 degrees with respect to the optical path axis.

[0157] BS holder 282 is fixed to plate 284. Plate 284 is fixed to plate 285. Plate 285 is fixed to plate 213. Other structures can be Figures 4 to 8 The structures shown are the same.

[0158] 6.2 Action

[0159] When the plate 213 slides in a direction perpendicular to the optical path axis and parallel to the optical surfaces of the beam splitters BS1 and BS2, the beam splitters BS1 and BS2 slide simultaneously.

[0160] 6.3 Function and effect

[0161] According to the configuration of the third embodiment, by sliding the beam splitters BS1 and BS2 simultaneously, when the beam splitters BS1 and BS2 deteriorate substantially at the same time, they can be restored by a single operation.

[0162] According to the configuration of the third embodiment, it is not necessary to provide slide mechanisms separately for the beam splitters BS1 and BS2 , and thus the configuration can be simplified.

[0163] 6.4 Variations

[0164] The structure of the third embodiment may also employ a structure using the linear guides 270 a and 270 b described in the second embodiment.

[0165] 7. Implementation Method 4

[0166] 7.1 Structure

[0167] Fig.16 The main part of the slide mechanism 204 of the OPS applied to the laser device 2 of the fourth embodiment is schematically shown. The slide mechanism 204 may be used instead of the slide mechanism 200 of the first embodiment. The slide mechanism 204 of the fourth embodiment is a structure that can move the half window 190 and the beam splitter 150 at the same time. In addition, the combination of the half window 190 and the beam splitter 150 may be Figure 2 The half window HW1 and the beam splitter BS1 described in the figure may also be the half window HW2 and the beam splitter BS2.

[0168] Fig.17 This is a side view including a partial cross section of the sliding mechanism 204 as viewed from the H direction. Fig.16 and Fig.17 The structure shown in the figure shows Figures 4 to 8 The difference between the sliding mechanism 200 described in FIG.

[0169] The sliding mechanism 204 includes a half window holder 292 that holds the half window 190 , a plate 294 that fixes the half window holder 292 , and a plate 297 that fixes the plate 294 to the plate 213 .

[0170] The half window 190 is arranged in a state where the optical surface 191 on which the laser beam is incident is inclined at 45 degrees with respect to the optical path axis.

[0171] The half window holder 292 is fixed to the plate 294. The plate 294 is fixed to the plate 297. The plate 297 is fixed to the plate 213. Other structures can be Figures 4 to 8 The half window holder 292 is an example of a "second holder" in the present disclosure.

[0172] 7.2 Action

[0173] When the plate 213 slides in a direction perpendicular to the optical path axis and parallel to the optical surface 151 of the beam splitter 150 , the beam splitter 150 and the half window 190 slide simultaneously.

[0174] 7.3 Function and effect

[0175] According to the configuration of the fourth embodiment, by sliding the beam splitter 150 and the half window 190 simultaneously, when the beam splitter 150 and the half window 190 deteriorate substantially at the same time, they can be restored by a single operation.

[0176] According to the structure of the fourth embodiment, it is not necessary to separately provide sliding mechanisms for the beam splitter 150 and the half window 190 , and thus the structure can be simplified.

[0177] 7.4 Variations

[0178] The structure of the fourth embodiment may also employ a structure using the linear guides 270 a and 270 b described in the second embodiment.

[0179] 8. Implementation Method 5

[0180] 8.1 Structure

[0181] Fig.18 This is a perspective view schematically showing the structure of OPS550 applied to the laser device 2 of the fifth embodiment. Fig.18 The structure shown in the figure shows Figure 2 Here, an example of OPS550 is shown in which a loop optical path LP is formed by a beam splitter BS and eight concave mirrors CM1 to CM8. Fig.18 The OPS550 shown here replaces Figure 2 The first OPS module 510 described in the figure. The eight concave mirrors CM1 to CM8 may be Figure 2The concave mirrors CM11 to CM18 described in the specification have the same structure.

[0182] The loop optical path LP of OPS550 does not include the half window HW1 compared to the loop optical path LP1 of the OPS module 510. Instead, it is provided with an angle measuring stage 554 or a tilting stage for changing the angle of the concave mirror CM7 preceding the last concave mirror CM8 in the loop optical path LP around the H axis. The angle measuring stage 554 or the tilting stage is an example of the "mirror angle adjustment mechanism" in the present disclosure.

[0183] In addition, OPS550 is provided with a uniaxial stage 556 for parallel movement of the last concave mirror CM8 of the loop optical path LP in the Z direction. Hereinafter, the last concave mirror CM8 in the loop optical path LP is referred to as "the last concave mirror CM8". In addition, the concave mirror CM7 before the last concave mirror CM8 is referred to as "the last last concave mirror CM7".

[0184] The other structures may be the same as those in the first embodiment.

[0185] 8.2 Action

[0186] The OPS550 of implementation mode 5 does not use a half window. In order to couple the loop light path LP with the transmitted light path of the beam splitter BS, the angle of the last preceding concave mirror CM7 is adjusted around the H-axis using a goniometer stage 554 or a tilt stage so that the incident position of the loop light toward the last concave mirror CM8 is offset by a specified distance.

[0187] In addition, the configuration position of the last concave mirror CM8 is moved parallel to the +Z direction by a specified distance through the uniaxial stage 556.

[0188] Without using the half-window loop optical path LP, the single-axis stage 556 can make the position offset of the light incident on the last concave mirror CM8 follow the size S of the following formula (1).

[0189] [Formula 1]

[0190]

[0191] In formula (1), t is the thickness of the transmission element, θ is the incident angle of the transmission element, and θ' is the refraction angle of the transmission element. The transmission element here is a half window. Fig.19 This is an explanatory diagram showing the parameters of equation (1). If the values ​​of the parameters are exemplified, for example, the typical value of t is 7.0 mm, the typical value of θ is 45.0 degrees, and the typical value of θ' is 30.0 degrees.

[0192] like Fig.19 As shown, the movement amount S of the last concave mirror CM8 in the +Z direction may be set to be the same as the displacement amount S of the laser light path caused by the half window (transmission element).

[0193] 8.3 Function and effect

[0194] According to the OPS550 of Embodiment 5, the optical path of the pulsed laser light transmitted through the beam splitter BS can be coupled to the loop optical path LP without configuring a half window, thereby eliminating the degradation of the transmittance of the half window compared to Embodiment 1. As a result, the number of components that need to be replaced due to degradation can be reduced.

[0195] In addition, the amount by which the configuration position of the last concave mirror CM8 is parallel shifted is the amount by which the optical path is shifted, thereby reducing the risk of vignetting caused by light irradiating outside the transparent aperture of the reflector accompanying the change in the optical path.

[0196] 8.4 Modification 1

[0197] For the second OPS module 520, similarly, the method of omitting the half window can be adopted. Figure 2 The concave mirror CM23 preceding the last concave mirror CM24 in the loop optical path LP2 is provided with a goniometer or tilting stage for changing the angle around the H axis. In addition, a uniaxial stage is provided for parallel movement of the last concave mirror CM24 in the Z direction.

[0198] 8.5 Modification 2

[0199] As a Fig.18 The mechanism for sliding the beam splitter BS in the embodiment may be the sliding mechanism 200 described in the first embodiment or the sliding mechanism 202 in the second embodiment. In the case of a structure in which two-stage OPS modules are combined, the sliding mechanism 203 in the third embodiment may be applied.

[0200] 9. Modification of Laser Device

[0201] Alternatively, a solid-state laser system including a semiconductor laser and a wavelength conversion system may be used. Figure 1 MO10 shown. The wavelength conversion system can be constructed using a nonlinear optical crystal. That is, the oscillation-level laser that generates the seed light is not limited to a gas laser, but can also be an ultraviolet solid laser that outputs a pulsed laser of an ultraviolet wavelength. For example, the oscillation-level laser can also be a solid laser that oscillates at a wavelength of about 193.4nm, or an ultraviolet solid laser that outputs the fourth harmonic light of a titanium sapphire laser (wavelength of about 774nm).

[0202] Additionally, the amplifier is not limited to having Figure 1The structure of the Fabry-Perot type resonator such as MO30 shown in the figure may also be a structure having a ring resonator. In addition, the amplifier is not limited to a structure having an optical resonator, and may also be a simple amplifier, such as an excimer amplifier. The amplifier may also be a multipath amplifier such as a three-way amplifier that amplifies by reflecting the seed light with a cylindrical mirror and passing it three times in the discharge space.

[0203] 10. On the manufacturing method of electronic devices

[0204] Fig. 20 The structure example of the exposure device 800 is schematically shown. 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 performs reduced projection of the laser light transmitted through the mask 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.

[0205] The exposure device 800 exposes the workpiece with a laser reflecting the mask pattern by synchronously moving the mask stage RT and the workpiece stage WT in parallel. 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.

[0206] 11. Others

[0207] 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 obvious to those skilled in the art that the embodiments of the present disclosure can be used in combination.

[0208] Unless otherwise expressly stated, the terms used in this specification and the entire claims should be interpreted as "non-limiting". 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 "1" should be interpreted as "at least 1" or "more than 1". 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 them with contents other than "A", "B" and "C".

Claims

1. A laser device comprising: a pair of electrodes that enable an electrical discharge to occur; and an optical pulse stretcher that extends the pulse width of a pulse laser generated by discharge between the electrodes, The optical pulse stretcher comprises: a beam splitter, wherein the optical surface for the pulse laser to be incident is arranged obliquely relative to the optical path axis of the pulse laser, and the pulse laser incident on the optical surface is separated into reflected laser and transmitted laser; a plurality of mirrors that guide the reflected laser to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction perpendicular to the discharge direction and parallel to the optical surface.

2. The laser device according to claim 1, wherein: The laser device includes a maintenance surface on which an openable and closable maintenance panel is formed, and a direction in which the beam splitter slides by the sliding mechanism intersects with the maintenance surface.

3. The laser device according to claim 1, wherein: The slide mechanism is capable of moving the beam splitter so that the pulse laser beam is incident on a position of the optical surface of the beam splitter that is different from a region that was previously irradiated with the pulse laser beam.

4. The laser device according to claim 1, wherein: When the direction of the discharge is set to the V direction, the direction of the optical path axis of the pulsed laser incident on the optical surface of the beam splitter is set to the Z direction, and the direction perpendicular to the V direction and the Z direction is set to the H direction, the sliding direction in which the sliding mechanism causes the beam splitter to slide is a direction parallel to the H direction.

5. The laser device according to claim 4, wherein: The sliding mechanism includes: a movable plate, which is connected to a first reference plane perpendicular to the Z direction and a second reference plane perpendicular to the V direction and slides along the H direction; and a rod, which applies a force in the H direction to the movable plate to keep the first retaining frame of the beam splitter fixed to the movable plate.

6. The laser device according to claim 5, wherein: The sliding mechanism includes a plate holder having a first plunger that presses the movable plate against the first reference surface and a second plunger that presses the movable plate against the second reference surface.

7. The laser device according to claim 5, wherein: The optical pulse stretcher includes a housing in which the beam splitter and the plurality of mirrors are arranged. The first reference plane and the second reference plane are reference planes of the housing or reference planes of components positioned and arranged relative to the reference plane of the housing.

8. The laser device according to claim 7, wherein: The rod extends outside the housing.

9. The laser device according to claim 8, wherein: The housing has a through hole through which the rod passes, and a sealing member for maintaining a sealed interior of the housing is disposed in the through hole.

10. The laser device according to claim 5, wherein: The laser device includes a handle for operating the lever, and a recess is formed in the handle for positioning and arranging the beam splitter at a predetermined position in the sliding direction.

11. The laser device according to claim 10, wherein: The laser device further includes a positioning plunger engaged with the recessed portion.

12. The laser device according to claim 5, wherein: The sliding mechanism includes a first plate fixed to the first holding frame and a second plate fixed to the first plate, wherein the second plate is fixed to the movable plate.

13. The laser device according to claim 5, wherein: The sliding mechanism includes a linear guide that slidably supports the movable plate.

14. The laser device according to claim 1, wherein: The laser device further includes a positioning mechanism that regulates an arrangement position of the beam splitter in a sliding direction in which the beam splitter is moved by the sliding mechanism.

15. The laser device according to claim 14, wherein: The positioning mechanism includes: a clamped component, which has a plurality of recesses, including a first recess that configures the beam splitter at a first position in the sliding direction and a second recess that configures the beam splitter at a second position in the sliding direction; and a positioning plunger that is clamped with any one of the plurality of recesses.

16. The laser device according to claim 1, wherein: The optical pulse stretcher includes a plurality of the beam splitters, and the sliding mechanism enables the plurality of the beam splitters to move simultaneously.

17. The laser device according to claim 1, wherein: The optical pulse stretcher includes a half window disposed in an optical path of the reflected laser light guided by the plurality of mirrors and returning to the beam splitter, and the slide mechanism moves the beam splitter and the half window simultaneously.

18. The laser device according to claim 5, wherein: The optical pulse stretcher includes a half window disposed in an optical path of the reflected laser light guided by the plurality of reflection mirrors and returning to the beam splitter, and a second holder holding the half window is fixed to the movable plate.

19. The laser device according to claim 4, wherein: The optical pulse stretcher does not have a half window in the optical path that uses the multiple mirrors to return the reflected laser to the beam splitter, and the laser device includes: a single-axis stage that moves the last mirror among the multiple mirrors along the Z direction; and a mirror angle adjustment mechanism that changes the angle of the previous mirror of the last mirror among the multiple mirrors around an H axis parallel to the H direction.

20. A method for manufacturing an electronic device, wherein: The manufacturing method of the electronic device comprises the following steps: generating a laser with an extended pulse width by a laser device; outputting the laser light to an exposure device; and exposing the photosensitive substrate to the laser in the exposure device to manufacture an electronic device, The laser device comprises: a pair of electrodes which generate discharge; And an optical pulse stretcher that expands the pulse width of a pulse laser generated by a discharge between the electrodes, the optical pulse stretcher comprising: a beam splitter, wherein an optical surface for the pulse laser to be incident is arranged obliquely relative to an optical path axis of the pulse laser, and the pulse laser incident on the optical surface is separated into a reflected laser and a transmitted laser; a plurality of mirrors that guide the reflected laser to the beam splitter; and a sliding mechanism that moves the beam splitter in a direction perpendicular to the direction of the discharge and parallel to the optical surface.

Images