Discharge electrode, method for manufacturing anode, and method for manufacturing electronic device

Abstract

A discharge electrode used in a gas laser device that excites a fluorine-containing laser gas by discharging is provided with a cathode and an anode. The positive electrode and the negative electrode are disposed so as to face each other, and comprise: an electrode base material containing a metal; and a coating layer that covers a part of a side surface parallel to the longitudinal direction of the electrode base material and contains an insulating material. The coating includes: a first portion covering a first region in the side surface; and a second portion that covers a second region in the side surface and is thicker than the first portion, the second region being located farther from the cathode than the first region in a discharge direction perpendicular to the longitudinal direction.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a discharge electrode, an anode, 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 higher 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) including narrowing elements (etalon, grating, etc.) is sometimes provided in the laser resonator of the gas laser device. Hereinafter, a gas laser device with a narrowed spectral line width is referred to as a narrowed gas laser device.

[0004] Prior art literature

[0005] Patent Literature

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2004-179599 Summary of the invention

[0007] A discharge electrode according to one aspect of the present disclosure is used in a gas laser device that excites laser gas containing fluorine by discharge, wherein the discharge electrode has a cathode and an anode, the anode and the cathode are arranged opposite to each other, and includes: an electrode substrate containing a metal; and a coating covering a portion of a side surface of the electrode substrate parallel to a longitudinal direction and containing an insulating material, the coating including: a first portion covering a first area in the side surface; and a second portion covering a second area in the side surface and being thicker than the first portion, the second area being located at a position farther from the cathode than the first area in a discharge direction perpendicular to the longitudinal direction.

[0008] A method for manufacturing an anode according to one aspect of the present disclosure, wherein the discharge electrode is used in a configuration opposite to a cathode in a gas laser device that excites a laser gas containing fluorine by discharge, wherein the manufacturing method includes: a first step of forming a coating on a side surface parallel to a length direction of an electrode substrate constituting the anode; and a second step of removing a portion of the coating so as to make it close to a target shape, the second step including the following process: removing a portion of the coating so that a second portion covering a second area in the side surface is thicker than a first portion covering a first area in the side surface, the second area being located at a position farther from the cathode than the first area in a discharge direction perpendicular to the length direction.

[0009] A method for manufacturing an electronic device according to one aspect of the present invention includes the following steps: generating laser light using a gas laser device including a laser chamber having a discharge electrode; outputting the laser light to an exposure device; and exposing the laser light on a photosensitive substrate in the exposure device to manufacture the electronic device. The discharge electrode is used in a gas laser device that excites a laser gas containing fluorine by discharge, and the discharge electrode includes a cathode and an anode. The anode and the cathode are arranged opposite to each other, and include: an electrode substrate including a metal; and a coating covering a portion of a side surface of the electrode substrate parallel to the longitudinal direction and including an insulating material. The coating includes: a first portion covering a first region in the side surface; and a second portion covering a second region in the side surface and being thicker than the first portion, the second region being located at a position farther from the cathode than the first region in a discharge direction perpendicular to the longitudinal direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings, merely as examples.

[0011] Figure 1 The structure of a gas laser device according to a comparative example is schematically shown.

[0012] Figure 2 To indicate Figure 1 The laser chamber and its internal structure are shown.

[0013] Figure 3 yes Figure 1 and Figure 2 A three-dimensional diagram of the cathode and anode shown.

[0014] Figure 4 is a cross-sectional view of an anode that has been in use for a long time.

[0015] Figure 5 The state of discharge between the cathode and the anode in the comparative example is schematically shown.

[0016] Figure 6 Schematically indicating that Figure 5 The situation after discharge between the cathode and the anode is shown.

[0017] Figure 7 Schematically shows Figure 5 The next discharge situation of the discharge between the cathode and the anode is shown.

[0018] Figure 8 Schematically shows Figure 5 The next discharge situation of the discharge between the cathode and the anode is shown.

[0019] Fig. 9 It shows the side surface of the anode when the thickness of the portion covering the side surface in the coating layer is reduced.

[0020] Fig.10 It is a cross-sectional view of an anode constituting the discharge electrode of the first embodiment.

[0021] Fig.11 It is a cross-sectional view of an anode constituting a discharge electrode according to a second embodiment.

[0022] Fig.12 It is a cross-sectional view showing a manufacturing process of an anode constituting the discharge electrode of the third embodiment.

[0023] Fig.13 It is a cross-sectional view showing a manufacturing process of an anode constituting the discharge electrode of the third embodiment.

[0024] Fig.14 It is a cross-sectional view showing a manufacturing process of an anode constituting the discharge electrode according to the fourth embodiment.

[0025] Fig.15 It is a cross-sectional view showing a manufacturing process of an anode constituting the discharge electrode according to the fourth embodiment.

[0026] Fig.16 The structure of an exposure device connected to a gas laser device is schematically shown. DETAILED DESCRIPTION

[0027] <Content>

[0028] 1. Comparative Example

[0029] 1.1 Structure of gas laser device 1

[0030] 1.2 Action

[0031] 1.3 Issues of Comparative Example

[0032] 2. Anode 11b with a step is provided on coating 112

[0033] 2.1 Structure

[0034] 2.2 Function

[0035] 3. The electrode substrate 111 is provided with a stepped anode 11b

[0036] 3.1 Structure

[0037] 3.2 Function

[0038] 4. Method for manufacturing anode 11b having steps in coating layer 112

[0039] 4.1 Manufacturing process

[0040] 4.2 Function

[0041] 5. Method for manufacturing anode 11b having a step on electrode substrate 111

[0042] 5.1 Manufacturing process

[0043] 5.2 Function

[0044] 6. Others

[0045] 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.

[0046] 1. Comparative Example

[0047] 1.1 Structure of gas laser device 1

[0048] Figure 1 The structure of a gas laser device 1 according to a comparative example is schematically shown. Figure 1 The gas laser device 1 shown includes a laser chamber 10, a cathode 11a and an anode 11b constituting a pair of discharge electrodes, a charger 12, a pulse power module (PPM) 13, a narrowband module 14, an output coupling mirror 15, and a laser controller 30. The narrowband module 14 and the output coupling mirror 15 constitute an optical resonator. The laser chamber 10 is arranged on the optical path of the optical resonator. Figure 1 , the internal structure of the laser chamber 10 is shown as viewed from a direction that is substantially perpendicular to the discharge direction between the cathode 11 a and the anode 11 b and substantially perpendicular to the traveling direction of the laser light output from the output coupling mirror 15 .

[0049] Figure 2 To indicate Figure 1 The laser chamber 10 and its internal structure are shown. Figure 1 , the internal structure of the laser chamber 10 viewed from a direction substantially parallel to the traveling direction of the laser light output from the output coupling mirror 15 is shown.

[0050] The traveling direction of the laser output from the output coupling mirror 15 is set to the +Z direction. The discharge direction between the cathode 11a and the anode 11b is set to the +V direction or the -V direction. The +Z direction and the +V direction are directions perpendicular to each other. The direction perpendicular to these two is set to the +H direction or the -H direction. The -V direction is roughly consistent with the direction of gravity.

[0051] The laser chamber 10 accommodates a cathode 11 a , an anode 11 b , a cross-flow fan 21 , and a heat exchanger 23 .

[0052] An opening is formed in a part of the laser chamber 10, and the opening is blocked by the electrical insulating portion 20. The electrical insulating portion 20 supports the cathode 11a. A plurality of conductive portions 20a are embedded in the electrical insulating portion 20. The conductive portions 20a are electrically connected to the cathode 11a, respectively.

[0053] A return plate 10c is disposed inside the laser chamber 10. The anode 11b is supported by the return plate 10c. The anode 11b is electrically connected to the ground potential via the return plate 10c and the conductive member of the laser chamber 10.

[0054] like Figure 2 As shown, the return plate 10c is Figure 1 There are gaps for laser gas to pass through on the deep side and the front side of the paper.

[0055] The rotating shaft of the cross flow fan 21 is connected to a motor 22 disposed outside the laser chamber 10. The motor 22 rotates the cross flow fan 21. Figure 2 As indicated by the arrow A, the laser gas circulates inside the laser chamber 10. The heat exchanger 23 discharges the heat energy of the laser gas heated to a high temperature by the discharge to the outside of the laser chamber 10.

[0056] In the laser chamber 10, for example, a laser gas such as argon or krypton as a rare gas, fluorine gas as a halogen gas, or neon gas as a buffer gas is sealed. Alternatively, a laser gas containing fluorine gas and a buffer gas may be sealed. Windows 10a and 10b are provided at both ends of the laser chamber 10.

[0057] The charger 12 holds electric energy for supplying to the pulse power module 13. The pulse power module 13 includes a charging capacitor and a switch 13a (not shown). The charging capacitor of the pulse power module 13 is connected to the charger 12. The cathode 11a is connected to the charging capacitor of the pulse power module 13 via the conductive portion 20a.

[0058] Figure 3 yes Figure 1 and Figure 2The cathode 11a and the anode 11b are shown in a three-dimensional view. The longitudinal direction of the cathode 11a and the anode 11b is substantially parallel to the Z axis. When viewed from the cathode 11a, the anode 11b is arranged opposite to the cathode 11a in the -V direction. Figure 3 2 shows the vicinity of both ends of the cathode 11 a and the anode 11 b in the longitudinal direction, and omits a portion of the center.

[0059] The anode 11b includes an electrode substrate 111 and a coating 112. The electrode substrate 111 includes a metal, and the coating 112 covers a portion of the surface of the electrode substrate 111 and includes an insulating material. The coating 112 is, for example, a sprayed film of copper and aluminum oxide. The side surface SS1 of the electrode substrate 111 and the side surface SS2 of the coating 112 are parallel to the length direction and the discharge direction of the electrode substrate 111. The discharge surface of the electrode substrate 111 facing the cathode 11a is set as the first discharge surface DS1. The discharge surface of the coating 112 facing the cathode 11a is set as the second discharge surface DS2.

[0060] In the present disclosure, the discharge surface refers to a surface facing other electrodes, and the other electrodes form a pair with the present electrode to serve as discharge electrodes. When the first discharge surface DS1 is covered with the coating layer 112, discharge does not necessarily occur on the first discharge surface DS1.

[0061] Refer again Figure 1 The narrowband module 14 includes a prism 14a and a grating 14b. A high reflective mirror may be used to replace the narrowband module 14.

[0062] The output coupling mirror 15 is made of a material that transmits the light of the selected wavelength of the band narrowing module 14 , and one surface thereof is coated with a partial reflection film.

[0063] 1.2 Action

[0064] The laser controller 30 is from the exposure device 100 (see Fig.16 ) receives the setting data of the target pulse energy and the light emission trigger signal. The laser controller 30 sends the setting data of the charging voltage to the charger 12 based on the setting data of the target pulse energy. In addition, the laser controller 30 sends a trigger signal to the pulse power module 13 based on the light emission trigger signal.

[0065] When receiving a trigger signal from the laser controller 30 , the pulse power module 13 generates a pulse-shaped high voltage using the electric energy charged in the charger 12 , and applies the high voltage between the cathode 11 a and the anode 11 b .

[0066] When a high voltage is applied between the cathode 11a and the anode 11b, a discharge occurs between the cathode 11a and the anode 11b. The laser medium in the laser chamber 10 is excited and transferred to a high energy level by the energy of the discharge. When the excited laser medium subsequently transfers to a low energy level, it emits light of a wavelength corresponding to the energy level difference.

[0067] Light generated in the laser chamber 10 is emitted to the outside of the laser chamber 10 through the windows 10a and 10b. The beam width of the light emitted from the window 10a of the laser chamber 10 is expanded in the H-axis direction by the prism 14a, and is incident on the grating 14b.

[0068] The light incident on the grating 14 b from the prism 14 a is reflected by the plurality of grooves of the grating 14 b and diffracted in a direction corresponding to the wavelength of the light.

[0069] The prism 14 a reduces the beam width of the diffracted light from the grating 14 b in the H-axis direction and returns the diffracted light to the laser chamber 10 through the window 10 a .

[0070] The output coupling mirror 15 transmits a part of the light emitted from the window 10 b of the laser chamber 10 to output the light, and reflects the other part to return the light to the inside of the laser chamber 10 .

[0071] In this way, the light emitted from the laser chamber 10 reciprocates between the narrowband module 14 and the output coupling mirror 15, and is amplified each time it passes through the discharge space between the cathode 11a and the anode 11b. The light is narrowbanded each time it is returned by the narrowband module 14. The light narrowbanded by laser oscillation is output from the output coupling mirror 15 as laser light.

[0072] 1.3 Issues of Comparative Example

[0073] Figure 4 1 is a cross-sectional view of the anode 11b used for a long time. When the anode 11b is used for a long time, the electrode substrate 111 may deteriorate starting from the vicinity of the first discharge surface DS1. For example, a part of the electrode substrate 111 may react with the fluorine contained in the laser gas and become brittle. In the coating 112, especially the part covering the side surface SS1, it is required to strengthen the brittle part 111a of the electrode substrate 111 and maintain the strength of the anode 11b.

[0074] Figure 5 The discharge between the cathode 11a and the anode 11b in the comparative example is schematically shown. A discharge space 50 is formed between the cathode 11a and the anode 11b.

[0075] The coating 112 contains an insulating material to suppress the surface degradation of the electrode substrate 111, and the resistivity of the material constituting the coating 112 is higher than the resistivity of the material constituting the electrode substrate 111. However, if the resistance of the coating 112 is too high, it is difficult to discharge, so the coating 112 contains metal in addition to the insulating material. In addition, when a high voltage is applied between the cathode 11a and the anode 11b, the electric field tends to concentrate near the corner of the anode 11b. Therefore, the discharge space 50 also reaches the vicinity of the corner of the coating 112.

[0076] Figure 6 Schematically indicating that Figure 5 The discharge between the cathode 11a and the anode 11b is shown in FIG. 1. The laser chamber 10 is provided with a cross flow fan 21 (see FIG. Figure 2 ) makes the laser gas circulate in the direction indicated by arrow A, so Figure 5 When observing the discharge space 50, the discharge product 51 including ions or metal particles generated by the discharge moves to a position in the +H direction.

[0077] Figure 7 and Figure 8 Schematically Figure 5 The next discharge between the cathode 11a and the anode 11b is shown in FIG. Figure 7 In the embodiment, the discharge product 51 is located near the cathode 11a and the anode 11b. Figure 8 In the embodiment, the discharge product 51 is located away from the cathode 11a and the anode 11b.

[0078] exist Figure 7 In the process, the flow of electrons from the cathode 11a to the anode 11b caused by the discharge is attracted by the discharge product 51. Therefore, Figure 7 The discharge space 50 in the discharge chamber is formed to be biased toward the +H direction, so that the discharge becomes unstable and the generation of laser light becomes unstable.

[0079] On the other hand, Figure 8 As shown in FIG. 1 , if the discharge product 51 is located away from the cathode 11a and the anode 11b, the discharge space 50 is hardly affected by the discharge product 51. Figure 5 The discharge space 50 in the embodiment is formed similarly.

[0080] In order to increase the distance from the cathode 11 a and the anode 11 b to the discharge product 51 without reducing the repetition frequency of the laser beam, there are the following methods (1) or (2).

[0081] (1) Increasing the flow rate of the laser gas by the cross flow fan 21

[0082] (2) Reducing the width of the discharge space 50 in the H-axis direction

[0083] However, when the flow rate of the laser gas is increased, the power consumption for driving the motor 22 may increase. The power consumption is proportional to the cube of the flow rate of the laser gas.

[0084] In order to reduce the width of the discharge space 50 in the H-axis direction, it is conceivable to narrow the width of the electrode substrate 111. However, if the width of the electrode substrate 111 is narrowed, degradation may advance to the center of the electrode substrate 111 in advance, and the life may be shortened.

[0085] Therefore, in order to reduce the width of the discharge space 50 in the H-axis direction, it is preferable that the thickness T0 of the portion of the coating layer 112 covering the side surface SS1 (see Figure 4 ) is the minimum.

[0086] Fig. 9 The side surface of the anode 11b is shown when the thickness T0 of the portion covering the side surface SS1 in the coating 112 is reduced. When the thickness T0 is 0.1 mm, peeling PL may sometimes occur in a portion of the coating 112 during the manufacture of the anode 11b. The peeling PL of the coating 112 occurs in a portion away from the second discharge surface DS2, so it has no significant effect on the discharge itself. However, there is a possibility that the deterioration of the electrode substrate 111 exposed by the peeling PL is accelerated.

[0087] Some embodiments described below achieve suppression of the width of the discharge space 50 in the H-axis direction from increasing or the width of the electrode substrate 111 from decreasing, and also achieve suppression of the peeling PL of the coating layer 112 .

[0088] 2. Anode 11b with a step provided on coating 112

[0089] 2.1 Structure

[0090] Fig.10 It is a cross-sectional view of the anode 11b constituting the discharge electrode of the first embodiment. Fig.10 The cross section perpendicular to the Z axis of the electrode substrate 111 and the coating layer 112 constituting the anode 11 b is shown. Fig.10 The cathode 11a not shown in the figure is located in the +V direction when viewed from the anode 11b. Figure 3 The cathodes described are the same.

[0091] The two side surfaces parallel to the length direction of the electrode substrate 111 include a first region R1, a second region R2, and a third region R3, respectively. The first region R1, the second region R2, and the third region R3 exist in order from the side close to the cathode 11a. The first portion P1 and the second portion P2 in the coating layer 112 cover the first region R1 and the second region R2, respectively.

[0092] The thickness T2 of the second portion P2 is greater than the thickness T1 of the first portion P1. For example, the thickness T1 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm, and the thickness T2 is greater than the thickness T1 by greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0093] At least a portion of the surface F1 of the first portion P1 is parallel to at least a portion of the first region R1 on the side surface of the electrode substrate 111 , and at least a portion of the surface F2 of the second portion P2 is parallel to at least a portion of the second region R2 on the side surface of the electrode substrate 111 .

[0094] Each part of the anode 11b has the following dimensional widths.

[0095] A first width W1 of the anode 11b including the first portion P1;

[0096] A second width W2 of the anode 11b including the second portion P2;

[0097] a third width W3 between the first regions R1;

[0098] a fourth width W4 between the second regions R2;

[0099] A fifth width W5 is defined between the third regions R3.

[0100] like Fig.10 As shown, the first region R1 and the second region R2 are flat. A step is formed between the surface F1 of the first portion P1 and the surface F2 of the second portion P2, and the second width W2 is greater than the first width W1. If the first portion P1 has a sufficient length L1 in the discharge direction, the step between the surfaces F1 and F2 will not affect the discharge, and the discharge width is determined by the first width W1.

[0101] However, the first region R1 and the second region R2 are not limited to being flat, as long as the difference between the third width W3 and the fourth width W4 is smaller than the difference between the first width W1 and the second width W2.

[0102] A step is formed between the second region R2 and the third region R3, and the fifth width W5 is larger than the fourth width W4. The surface F2 of the second portion P2 is flat between the third region R3.

[0103] However, the surface F2 and the third region R3 are not limited to being flat, and the difference between the fifth width W5 and the second width W2 only needs to be smaller than the difference between the first width W1 and the second width W2.

[0104] Preferably, the length L2 of the second portion P2 in the discharge direction is longer than the length L1 of the first portion P1 in the discharge direction. The length L1 of the first portion P1 in the discharge direction is 1.5 mm or more, for example, 2.0 mm. The length L2 of the second portion P2 in the discharge direction is 3.0 mm or more, for example, 4.0 mm.

[0105] 2.2 Function

[0106] (1) The discharge electrode of the first embodiment is a discharge electrode used in a gas laser device 1 that excites a laser gas containing fluorine by discharge, and includes a cathode 11a and an anode 11b. The anode 11b is arranged opposite to the cathode 11a, and includes: an electrode substrate 111 that includes a metal; and a coating 112 that covers a portion of a side surface of the electrode substrate 111 parallel to the longitudinal direction and includes an insulating material. The coating 112 includes: a first portion P1 that covers a first region R1 on the side surface of the electrode substrate 111; and a second portion P2 that covers a second region R2 on the side surface of the electrode substrate 111 and is thicker than the first portion P1, and the second region R2 is located at a position farther from the cathode 11a than the first region R1 in a discharge direction perpendicular to the longitudinal direction.

[0107] Thus, the width of the electrode substrate 111 is sufficiently ensured to suppress degradation of the electrode substrate 111 , the thickness of the first portion P1 of the coating 112 is reduced to suppress increase in discharge width, and the thickness of the second portion P2 of the coating 112 is increased to suppress peeling.

[0108] (2) In the first embodiment, at least a portion of the surface F1 of the first portion P1 of the coating layer 112 is parallel to at least a portion of the first region R1 of the side surface of the electrode substrate 111 .

[0109] Thus, the first portion P1 of the coating layer 112 can be processed with high dimensional accuracy by, for example, thermal spraying and grinding.

[0110] (3) In the first embodiment, at least a portion of the surface F2 of the second portion P2 of the coating layer 112 is parallel to at least a portion of the second region R2 of the side surface of the electrode substrate 111 .

[0111] Thus, the second portion P2 of the coating layer 112 can be processed with high dimensional accuracy by, for example, thermal spraying and grinding.

[0112] (4) In the first embodiment, the first region R1 and the second region R2 and the first portion P1 and the second portion P2 are respectively located on two side surfaces parallel to the length direction of the electrode substrate 111. Furthermore, the difference between the third width W3 between the first regions R1 and the fourth width W4 between the second regions R2 is smaller than the difference between the first width W1 of the anode 11b including the first portion P1 and the second width W2 of the anode 11b including the second portion P2.

[0113] Thus, the difference between the third width W3 and the fourth width W4 is small, so the processing of the electrode substrate 111 can be facilitated, and the thicknesses T1 and T2 of the first portion P1 and the second portion P2 can be adjusted by adjusting the difference between the first width W1 and the second width W2.

[0114] (5) In the first embodiment, the side surface of the electrode substrate 111 includes the third region R3 located farther from the cathode 11a than the second region R2 in the discharge direction, and the first region R1 to the third region R3 and the first portion P1 and the second portion P2 are respectively located on two side surfaces parallel to the longitudinal direction of the electrode substrate 111. Furthermore, the difference between the fifth width W5 and the second width W2 between the third regions R3 is smaller than the difference between the first width W1 of the anode 11b including the first portion P1 and the second width W2 of the anode 11b including the second portion P2.

[0115] Thus, since the difference between the fifth width W5 and the second width W2 is small, the second portion P2 can be processed with high dimensional accuracy based on the third region R3.

[0116] (6) In the first embodiment, the first region R1 and the second region R2 of the side surface of the electrode substrate 111 are flat, and a step is formed between the surface F1 of the first portion P1 and the surface F2 of the second portion P2 of the coating layer 112 .

[0117] Thus, since the first region R1 and the second region R2 are made flat, the processing of the electrode substrate 111 can be facilitated, and the thicknesses T1 and T2 of the first portion P1 and the second portion P2 can be adjusted by adjusting the step between the surface F1 of the first portion P1 and the surface F2 of the second portion P2.

[0118] (7) In the first embodiment, the side surface of the electrode substrate 111 includes a third region R3 located farther from the cathode 11a than the second region R2 in the discharge direction, and the surface F2 of the second portion P2 of the coating 112 is flat with the third region R3 on the side surface of the electrode substrate 111.

[0119] Thus, since the surface F2 of the second portion P2 is made flat with respect to the third region R3 , the second portion P2 can be processed with high dimensional accuracy based on the third region R3 .

[0120] (8) In the first embodiment, the thickness T1 of the first portion P1 in the direction perpendicular to the side surface of the electrode substrate 111 is greater than 0.1 mm and less than 0.2 mm, and the thickness T2 of the second portion P2 in the direction perpendicular to the side surface of the electrode substrate 111 is greater than 0.05 mm and less than 0.5 mm thicker than the first portion P1.

[0121] Thus, the first portion P1 can have a sufficient thickness T1 for reinforcing the electrode substrate 111 and can suppress the discharge width from increasing. Also, the second portion P2 can have a sufficient thickness T2 to suppress separation during manufacturing and can suppress difficulty in processing the second portion P2.

[0122] (9) In the first embodiment, the length L2 of the second portion P2 in the discharge direction is longer than the length L1 of the first portion P1 in the discharge direction.

[0123] Thereby, the peeling of the second portion P2 can be sufficiently suppressed.

[0124] Regarding other aspects, the first embodiment is the same as the comparative example.

[0125] 3. Anode 11b having a step is provided on electrode substrate 111

[0126] 3.1 Structure

[0127] Fig.11 It is a cross-sectional view of an anode 11 b constituting a discharge electrode according to the second embodiment. Fig.11 The cross section perpendicular to the Z axis of the electrode substrate 111 and the coating layer 112 constituting the anode 11 b is shown. Fig.11 The cathode 11 a (not shown) is located in the +V direction when viewed from the anode 11 b.

[0128] like Fig.11 As shown, a step is formed between the first region R1 and the second region R2, a step is formed between the second region R2 and the third region R3, the third width W3 is greater than the fourth width W4, and the fifth width W5 is greater than the third width W3. Moreover, the surface F1 of the first portion P1 is flat with the surface F2 of the second portion P2, and the surface F2 of the second portion P2 is flat with the third region R3.

[0129] However, the surface F1 and the surface F2 are not limited to being flat, as long as the difference between the first width W1 and the second width W2 is smaller than the difference between the third width W3 and the fourth width W4. In addition, the surface F2 and the third region R3 are not limited to being flat, as long as the difference between the fifth width W5 and the second width W2 is smaller than the difference between the third width W3 and the fourth width W4.

[0130] 3.2 Function

[0131] (10) In the second embodiment, the first region R1 and the second region R2 and the first portion P1 and the second portion P2 are respectively located on two side surfaces parallel to the length direction of the electrode substrate 111. Furthermore, the difference between the first width W1 of the anode 11b including the first portion P1 and the second width W2 of the anode 11b including the second portion P2 is smaller than the difference between the third width W3 between the first region R1 and the fourth width W4 between the second region R2.

[0132] Thus, by reducing the difference between the first width W1 and the second width W2, the first portion P1 and the second portion P2 of the coating layer 112 can be processed with high dimensional accuracy. In addition, the shape of the components arranged around the anode 11b can be prevented from becoming complicated.

[0133] (11) In the second embodiment, the side surface of the electrode substrate 111 includes a third region R3 located farther from the cathode 11a than the second region R2 in the discharge direction, and the first region R1 to the third region R3 and the first portion P1 and the second portion P2 are respectively located on two side surfaces parallel to the longitudinal direction of the electrode substrate 111. Furthermore, the difference between the fifth width W5 between the third regions R3 and the second width W2 of the anode 11b including the second portion P2 is smaller than the difference between the third width W3 between the first regions R1 and the fourth width W4 between the second regions R2.

[0134] Thus, since the difference between the fifth width W5 and the second width W2 is small, the second portion P2 can be processed with high dimensional accuracy based on the third region R3.

[0135] (12) In the second embodiment, the third width W3 between the first regions R1 is greater than the fourth width W4 between the second regions R2.

[0136] Thus, it is easy to process the second portion P2 covering the second region R2 to be thicker than the first portion P1 covering the first region R1.

[0137] (13) In the second embodiment, the surface F1 of the first portion P1 and the surface F2 of the second portion P2 of the coating layer 112 are flat.

[0138] This makes it possible to process the first portion P1 and the second portion P2 with high dimensional accuracy. In addition, it is possible to prevent the shapes of components disposed around the anode 11 b from becoming complicated.

[0139] (14) In the second embodiment, the side surface of the electrode substrate 111 includes a third region R3 located farther away from the cathode 11a than the second region R2 in the discharge direction, the third width W3 between the first regions R1 is greater than the fourth width W4 between the second regions R2, and the fifth width W5 between the third regions R3 is greater than the third width W3.

[0140] Thus, by processing the first portion P1 and the second portion P2 based on the third region R3, it is easy to process the second portion P2 covering the second region R2 to be thicker than the first portion P1 covering the first region R1.

[0141] (15) In the second embodiment, the side surface of the electrode substrate 111 includes a third region R3 located farther from the cathode 11a than the second region R2 in the discharge direction, and the surface F2 of the second portion P2 of the coating 112 is flat with the third region R3 on the side surface of the electrode substrate 111.

[0142] Thus, by making the surface F2 of the second portion P2 and the third region R3 flat, the second portion P2 can be processed with high dimensional accuracy based on the third region R3.

[0143] Regarding other aspects, the second embodiment is the same as the first embodiment.

[0144] 4. Method for manufacturing anode 11b having a step in coating layer 112

[0145] 4.1 Manufacturing process

[0146] Fig.12 and Fig.13 It is a cross-sectional view showing a manufacturing process of the anode 11b constituting the discharge electrode according to the third embodiment. Fig.12 and Fig.13 1 shows a cross section perpendicular to the Z axis of the electrode substrate 111 and the coatings 112 and 112a constituting the anode 11b. Fig.12 and Fig.13 The cathode 11a not shown in the figure is arranged in the +V direction when viewed from the anode 11b. Fig.12 and Fig.13 In FIG. 1 , the unevenness of the surface of the coating layer 112 a is exaggeratedly depicted.

[0147] The anode 11b is manufactured as follows.

[0148] like Fig.12As shown in FIG. 1 , a coating layer 112a is formed on a side surface SS1 parallel to the longitudinal direction of an electrode substrate 111 constituting an anode 11b and a first discharge surface DS1 which is a surface opposite to the cathode 11a. The coating layer 112a is formed, for example, by spraying. The sprayed film is formed to have a substantially uniform thickness along the outer shape of the electrode substrate 111. The step of forming the coating layer 112a corresponds to the first step in the present disclosure.

[0149] like Fig.13 As shown, for example, by grinding or polishing the coating 112a, a portion of the coating 112a is removed to make it close to the target shape. At this time, a portion of the coating 112a is removed so that the second portion P2 covering the second region R2 in the side SS1 is thicker than the first portion P1 covering the first region R1 in the side SS1. As a result, a step is formed between the surface F1 of the first portion P1 and the surface F2 of the second portion P2. In addition, a second discharge surface DS2 is also formed. The process of removing a portion of the coating 112a is equivalent to the second process in the present disclosure.

[0150] Thereby, the coating layer 112 having the shape described in the first embodiment is formed.

[0151] 4.2 Function

[0152] (16) A manufacturing method according to a third embodiment is a manufacturing method for an anode 11b of a discharge electrode used in a gas laser device 1 for exciting a laser gas containing fluorine by discharge, and arranged to face a cathode 11a, the method comprising: a first step of forming a coating 112a on a side surface parallel to a longitudinal direction of an electrode substrate 111 constituting the anode 11b; and a second step of removing a portion of the coating 112a so as to approximate a target shape. The second step includes a process of removing a portion of the coating 112a so that a second portion P2 covering a second region R2 on the side surface of the electrode substrate 111 is thicker than a first portion P1 covering a first region R1 on the side surface of the electrode substrate 111, the second region R2 being located farther from the cathode 11a than the first region R1 in a discharge direction perpendicular to the longitudinal direction.

[0153] Thus, the coating 112 can be processed with high dimensional accuracy, and the width of the electrode substrate 111 can be sufficiently ensured to suppress degradation of the electrode substrate 111. At the same time, the discharge width can be suppressed from increasing by suppressing the thickness of the first part P1 of the coating 112, and peeling during manufacturing can be suppressed by thickening the second part P2 of the coating 112.

[0154] (17) In the third embodiment, the second step includes forming a step between the surface F1 of the first portion P1 and the surface F2 of the second portion P2 of the coating layer 112 .

[0155] Thus, by adjusting the step between the surface F1 of the first portion P1 and the surface F2 of the second portion P2 , the thicknesses of the first portion P1 and the second portion P2 can be adjusted.

[0156] Regarding other aspects, the third embodiment is the same as the first embodiment.

[0157] 5. Method for manufacturing anode 11b having a step on electrode substrate 111

[0158] 5.1 Manufacturing process

[0159] Fig.14 and Fig.15 It is a cross-sectional view showing a manufacturing process of the anode 11b constituting the discharge electrode according to the fourth embodiment. Fig.14 and Fig.15 1 shows a cross section perpendicular to the Z axis of the electrode substrate 111 and the coatings 112 and 112a constituting the anode 11b. Fig.14 and Fig.15 The cathode 11a not shown in the figure is arranged in the +V direction when viewed from the anode 11b. Fig.14 and Fig.15 In FIG. 1 , the unevenness of the surface of the coating layer 112 a is exaggeratedly depicted.

[0160] The anode 11b is manufactured as follows.

[0161] like Fig.14 That is, the electrode substrate 111 is processed so that the fourth width W4 between the second regions R2 is smaller than the third width W3 between the first regions R1 of the electrode substrate 111 constituting the anode 11b. The step of processing the electrode substrate 111 corresponds to the third step in the present disclosure.

[0162] Next, a coating layer 112a is formed on the first region R1 to the third region R3 of the side surface of the electrode substrate 111 and the first discharge surface DS1 which is the surface facing the cathode 11a. The coating layer 112a is formed, for example, by thermal spraying. The thermal sprayed film is formed to have a substantially uniform thickness along the outer shape of the electrode substrate 111. The step of forming the coating layer 112a corresponds to the first step in the present disclosure.

[0163] like Fig.15 As shown, for example, by grinding or polishing the coating 112a, a portion of the coating 112a is removed to make it close to the target shape. As a result, the step between the surface F1 of the first part P1 and the surface F2 of the second part P2 is reduced. In addition, a second discharge surface DS2 is formed. The process of removing a portion of the coating 112a is equivalent to the second process in the present disclosure.

[0164] Thereby, the coating layer 112 having the shape described in the second embodiment is formed.

[0165] 5.2 Function

[0166] (18) In the fourth embodiment, the first region R1 and the second region R2 are respectively located on two side surfaces parallel to the length direction of the electrode substrate 111. The method for manufacturing the anode 11b includes a third step before the first step, in which the electrode substrate 111 is processed so that the fourth width W4 between the second regions R2 is smaller than the third width W3 between the first regions R1.

[0167] Thus, it is easy to process the second portion P2 covering the second region R2 to be thicker than the first portion P1 covering the first region R1.

[0168] (19) In the fourth embodiment, the second step includes a process of reducing the step between the surface F1 of the first portion P1 and the surface F2 of the second portion P2 of the coating layer 112 .

[0169] Thus, the first portion P1 and the second portion P2 can be processed with high dimensional accuracy.

[0170] Regarding other aspects, the fourth embodiment is the same as the second embodiment.

[0171] 6. Others

[0172] Fig.16 The structure of the exposure device 100 connected to the gas laser device 1 is schematically shown. The gas laser device 1 generates laser light and outputs the laser light to the exposure device 100 .

[0173] exist Fig.16 In the embodiment, the exposure device 100 includes an illumination optical system 40 and a projection optical system 41. The illumination optical system 40 uses the laser light incident from the gas laser device 1 to illuminate the mask pattern of the mask (not shown) arranged on the mask stage RT. The projection optical system 41 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. The exposure device 100 exposes the laser light reflecting the mask pattern on the workpiece 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-mentioned exposure process, electronic devices can be manufactured through multiple processes.

[0174] 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.

[0175] 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 "1 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 them with contents other than "A", "B" and "C".

Claims

1. A discharge electrode used in a gas laser device for exciting a laser gas containing fluorine by discharge, wherein: The discharge electrode comprises a cathode and an anode, The anode and the cathode are arranged opposite to each other, and the anode comprises: an electrode substrate comprising a metal; and a coating layer covering a portion of the side surface of the electrode substrate parallel to the length direction and comprising an insulating material, The coating comprises: a first portion covering a first area in the side surface; and The second portion covers a second region in the side surface and is thicker than the first portion, the second region being located farther from the cathode than the first region in a discharge direction perpendicular to the longitudinal direction.

2. The discharge electrode according to claim 1, wherein: At least a portion of a surface of the first portion of the coating is parallel to at least a portion of the first region of the side.

3. The discharge electrode according to claim 1, wherein: At least a portion of a surface of the second portion of the coating is parallel to at least a portion of the second region of the side.

4. The discharge electrode according to claim 1, wherein The first region and the second region and the first portion and the second portion are respectively located on two side surfaces including the side surface and parallel to the length direction. A difference between a third width between the first regions and a fourth width between the second regions is smaller than a difference between a first width of the anode including the first portion and a second width of the anode including the second portion.

5. The discharge electrode according to claim 1, wherein The side surface includes a third region, the third region being located farther from the cathode than the second region in the discharge direction, The first to third regions and the first and second portions are respectively located on two side surfaces including the side surface and parallel to the longitudinal direction. A difference between a fifth width between the third regions and a second width of the anode including the second portion is smaller than a difference between a first width of the anode including the first portion and the second width.

6. The discharge electrode according to claim 1, wherein The first area and the second area of ​​the side surface are flat, A step is formed between a surface of the first portion and a surface of the second portion of the coating.

7. The discharge electrode according to claim 6, wherein: The side surface includes a third region, the third region being located farther from the cathode than the second region in the discharge direction, A surface of the second portion of the coating is flat with respect to the third region of the side surface.

8. The discharge electrode according to claim 1, wherein The thickness of the first portion in a direction perpendicular to the side surface is greater than or equal to 0.1 mm and less than or equal to 0.2 mm, The second portion is thicker than the first portion by 0.05 mm or more and 0.5 mm or less in a direction perpendicular to the side surface.

9. The discharge electrode according to claim 1, wherein: The length of the second portion in the discharge direction is longer than the length of the first portion in the discharge direction.

10. The discharge electrode according to claim 1, wherein The first region and the second region and the first portion and the second portion are respectively located on two side surfaces including the side surface and parallel to the length direction, A difference between a first width of the anode including the first portion and a second width of the anode including the second portion is smaller than a difference between a third width between the first regions and a fourth width between the second regions.

11. The discharge electrode according to claim 1, wherein The side surface includes a third region, the third region being located farther from the cathode than the second region in the discharge direction, The first to third regions and the first and second portions are respectively located on two side surfaces including the side surface and parallel to the longitudinal direction. A difference between a fifth width between the third regions and a second width of the anode including the second portion is smaller than a difference between a third width between the first regions and a fourth width between the second regions.

12. The discharge electrode according to claim 1, wherein The third width between the first regions is greater than the fourth width between the second regions.

13. The discharge electrode according to claim 12, wherein: A surface of the first portion of the coating is planar with a surface of the second portion thereof.

14. The discharge electrode according to claim 12, wherein: The side surface includes a third region, the third region being located farther from the cathode than the second region in the discharge direction, The fifth width between the third regions is greater than the third width.

15. The discharge electrode according to claim 12, wherein: The side surface includes a third region, the third region being located farther from the cathode than the second region in the discharge direction, A surface of the second portion of the coating is flat with respect to the third region of the side surface.

16. A method for manufacturing an anode of a discharge electrode, the discharge electrode being used in a gas laser device for exciting a laser gas containing fluorine by discharge in a configuration facing a cathode, wherein: The manufacturing method comprises: The first step is to form a coating on a side surface parallel to the longitudinal direction of an electrode substrate constituting the anode; and The second step is to remove a portion of the coating to make the target shape close to the target shape. The second step includes the following process: removing a portion of the coating so that a second portion covering a second area in the side surface is thicker than a first portion covering a first area in the side surface, the second area being located farther from the cathode than the first area in a discharge direction perpendicular to the longitudinal direction.

17. The manufacturing method according to claim 16, wherein: The second step includes forming a step between a surface of the first portion and a surface of the second portion of the coating.

18. The manufacturing method according to claim 16, wherein: The first region and the second region are respectively located on two side surfaces including the side surface and parallel to the length direction, The manufacturing method further includes a third step before the first step. In the third step, the electrode substrate is processed so that a fourth width between the second regions is smaller than a third width between the first regions.

19. The manufacturing method according to claim 18, wherein: The second step includes reducing a step between a surface of the first portion and a surface of the second portion of the coating.

20. A method for manufacturing an electronic device, wherein: The manufacturing method of the electronic device comprises the following steps: Generating laser light using a gas laser device; outputting the laser light to an exposure device; and exposing the laser on a photosensitive substrate in the exposure device to manufacture an electronic device, The gas laser device includes a laser chamber having a discharge electrode, the discharge electrode being used to excite a laser gas containing fluorine by discharge, the discharge electrode including a cathode and an anode. The anode and the cathode are arranged opposite to each other, and the anode includes: an electrode substrate containing a metal; and a coating covering a portion of a side surface of the electrode substrate parallel to a longitudinal direction and containing an insulating material. The coating includes: a first portion covering a first area in the side surface; and a second portion covering a second area in the side surface and being thicker than the first portion, the second area being located farther from the cathode than the first area in a discharge direction perpendicular to the length direction.

Images