Laser device and method for manufacturing electronic device

Abstract

The invention provides a laser apparatus and a method of manufacturing an electronic device. This laser device is provided with: a laser chamber in which a fluorine-containing laser gas is accommodated; a pair of discharge electrodes disposed in the laser cavity; a gas supply port disposed in the laser chamber; and an XeF2 crystal that is disposed in an XeF2 gasification space communicating with the gas supply port and is gasified.

Description

Technical Field

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

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

[0003] The spectral line width of the natural oscillation light of the KrF excimer laser device and the ArF excimer laser device is relatively wide, about 350 to 400 pm. Therefore, when the projection lens is constructed using a material that allows ultraviolet light such as KrF and ArF lasers to pass through, chromatic aberration sometimes occurs. 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. A gas laser device with a narrowed spectral line width is called a narrowed gas laser device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent Application Publication No. 2019 / 0237928 Summary of the invention

[0007] A laser device according to one aspect of the present disclosure comprises: a laser cavity that accommodates fluorine-containing laser gas; a pair of discharge electrodes that are arranged in the laser cavity; a gas supply port that is arranged in the laser cavity; and a XeF2 crystal that is arranged in a XeF2 vaporization space connected to the gas supply port and is vaporized.

[0008] A method for manufacturing an electronic device according to one aspect of the present disclosure includes the following steps: generating a laser by a laser device, outputting the laser to an exposure device, and exposing the laser on a photosensitive substrate in the exposure device to manufacture the electronic device, wherein the laser device comprises: a laser cavity that accommodates a fluorine-containing laser gas; a pair of discharge electrodes that are arranged in the laser cavity; a gas supply port that is arranged in the laser cavity; and a XeF2 crystal that is arranged in a XeF2 vaporization space connected to the gas supply port and is vaporized. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Hereinafter, several embodiments of the present disclosure will be described as simple examples with reference to the accompanying drawings.

[0010] Figure 1 The structure of an exposure system in a comparative example is shown.

[0011] Figure 2 The structure of an exposure system in a comparative example is shown.

[0012] Figure 3 The structure of a part of the laser device of the comparative example as viewed in the Z direction is shown.

[0013] Figure 4 A mechanism for supplying xenon gas in the first embodiment is shown.

[0014] Figure 5 Details of the XeF2 container are shown.

[0015] Figure 6 TABLE 2 is a table showing the relationship between the temperature T and the vapor pressure VP of a XeF2 crystal.

[0016] Figure 7 This is a flowchart showing the procedure of supplying xenon gas in the first embodiment.

[0017] Figure 8 This is a flowchart showing the details of the pre-processing in the first embodiment.

[0018] Fig. 9 1 is a flowchart showing details of a process for generating XeF 2 gas in a XeF 2 container in the first embodiment.

[0019] Fig.10 This is a flowchart showing details of the process of exhausting the gas in the laser cavity in the first embodiment.

[0020] Fig.11 This is a flowchart showing details of the process of supplying gas into the laser cavity in the first embodiment.

[0021] Fig.12 This is a flowchart showing the details of the process of filling the XeF2 container with an inert gas in the first embodiment.

[0022] Fig.13 This is a flowchart showing the details of the post-processing in the first embodiment.

[0023] Fig.14 An example of the relationship between the XeF2 concentration Cf and the actual xenon concentration Cx is shown.

[0024] Fig.15An example of the relationship between the XeF2 concentration Cf and the pulse energy deviation is shown.

[0025] Fig.16 The structure of the buffer tank in the second embodiment is shown.

[0026] Fig.17 1 is a flowchart showing details of a process for generating XeF 2 gas in a XeF 2 container in the second embodiment.

[0027] Fig.18 A mechanism for supplying xenon gas in the third embodiment is shown.

[0028] Fig.19 The structure of a part of the laser device according to the fourth embodiment as viewed in the -V direction is shown.

[0029] Fig. 20 A partial structure of the laser device according to the fourth embodiment as viewed in the Z direction is shown. DETAILED DESCRIPTION

[0030] <Content>

[0031] 1. Comparative Example

[0032] 1.1 Exposure system

[0033] 1.2 Exposure device 200

[0034] 1.2.1 Structure

[0035] 1.2.2 Action

[0036] 1.3 Laser device 100

[0037] 1.3.1 Structure

[0038] 1.3.2 Action

[0039] 1.4 Issues of Comparative Example

[0040] 2. Xenon gas supply using XeF2 crystal

[0041] 2.1 Structure

[0042] 2.2 Actions

[0043] 2.2.1 Main Process

[0044] 2.2.2 Preprocessing

[0045] 2.2.3 Processing of generating XeF2 gas in XeF2 container 47b 2.2.4 Processing of exhausting gas in laser cavity 10

[0046] 2.2.5 Processing of supplying gas into the laser cavity 10

[0047] 2.2.6 Processing of filling the XeF2 container 47b with inert gas 2.2.7 Post-processing

[0048] 2.3 Correction of XeF2 concentration Cf

[0049] 2.4 Function

[0050] 3. Dissociation of XeF2 gas based on discharge reactor

[0051] 3.1 Structure

[0052] 3.2 Actions

[0053] 3.3 Function

[0054] 4. Gas regeneration device 49 including buffer tank 47a

[0055] 4.1 Structure

[0056] 4.2 Xenon Addition Operation in Gas Regeneration Device 49

[0057] 4.3 Xenon addition in new gas supply

[0058] 4.4 Function

[0059] 5. XeF2 crystal 54 arranged in the flow path of the airflow generated by the cross flow fan 21

[0060] 5.1 Structure

[0061] 5.2 Actions

[0062] 5.3 Function

[0063] 6. Others

[0064] Below, the embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The embodiments described below show several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and actions described in each embodiment are not necessarily all necessary for the structures and actions of the present disclosure. In addition, the same reference numerals are marked on the same structural elements and repeated descriptions are omitted.

[0065] 1. Comparative Example

[0066] 1.1 Exposure system

[0067] Figure 1 and Figure 2 The structure of the exposure system in the comparative example is shown. The comparative example of the present disclosure is a method that the applicant recognizes that only the applicant knows, and is not a publicly known example acknowledged by the applicant himself.

[0068] The exposure system includes a laser device 100 and an exposure device 200. Figure 1 The laser device 100 is schematically shown in FIG. Figure 2 The exposure device 200 is schematically shown in FIG. 1 . The laser device 100 is configured to output laser light toward the exposure device 200 .

[0069] 1.2 Exposure device 200

[0070] 1.2.1 Structure

[0071] like Figure 1 As shown, the exposure device 200 includes an illumination optical system 201 and a projection optical system 202. The illumination optical system 201 illuminates the mask pattern of the mask (not shown) arranged on the mask stage RT by the laser light incident from the laser device 100. The projection optical system 202 performs reduced projection of the laser light transmitted through the mask to form an image 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 resist film.

[0072] 1.2.2 Action

[0073] The exposure device 200 causes the mask stage RT and the work stage WT to move synchronously and parallel to opposite directions. Thus, the workpiece is exposed using laser light reflecting the mask pattern. Through this exposure process, the mask pattern is transferred to the semiconductor wafer. Then, electronic devices can be manufactured through multiple processes.

[0074] 1.3 Laser device 100

[0075] 1.3.1 Structure

[0076] like Figure 2 As shown, the laser device 100 includes a laser cavity 10, a pair of discharge electrodes 11a and 11b, a narrowband module 14, an output coupling mirror 15, a gas supply device 42, an exhaust device 43, a processor 130 and a pressure gauge P3. The narrowband module 14 and the output coupling mirror 15 constitute an optical resonator. The laser cavity 10 is arranged on the optical path of the optical resonator. The processor 130 is a processing device including a memory 131 storing a control program and a CPU (central processing unit) 132 executing the control program. The processor 130 is specially configured or programmed to execute various processes included in the present disclosure.

[0077] The traveling direction of the laser light output from the output coupling mirror 15 is defined as the Z direction. The discharge direction between the discharge electrodes 11a and 11b is defined as the V direction or the -V direction. The Z direction and the V direction are perpendicular to each other, and the direction perpendicular to both of them is defined as the H direction or the -H direction. Figure 22 shows the structure of the laser device 100 viewed in the -H direction. Figure 3 The structure of a part of the laser device 100 according to the comparative example as viewed in the Z direction is shown.

[0078] The laser cavity 10 accommodates discharge electrodes 11a and 11b, a cross flow fan 21, a heat exchanger 23, and a preionization electrode 24. Windows 10a and 10b are provided at both ends in the ±Z direction of the laser cavity 10. The cross flow fan 21 is equivalent to a fan in the present disclosure.

[0079] Laser gas containing, for example, argon or krypton as a rare gas, fluorine gas as a halogen gas, neon gas as a buffer gas, etc. is sealed in laser cavity 10. Alternatively, laser gas containing fluorine gas and a buffer gas may be sealed.

[0080] An opening is formed in a part of the laser cavity 10, and the opening is blocked by the electrical insulating portion 20. The electrical insulating portion 20 supports the discharge electrode 11a. A plurality of conductive portions 20a are embedded in the electrical insulating portion 20. The conductive portions 20a are electrically connected to the discharge electrode 11a, respectively. A power supply device (not shown) is connected to the discharge electrode 11a via the conductive portions 20a.

[0081] A reset plate 10c is disposed inside the laser cavity 10. The discharge electrode 11b is supported by the reset plate 10c. The discharge electrode 11b is electrically connected to the ground potential via the reset plate 10c and the conductive member of the laser cavity 10. Figure 3 As shown, the reset plate 10c is Figure 2 The back side and the front side of the paper have gaps for the laser gas to pass through. The rotating shaft of the cross flow fan 21 is supported by a bearing fixed to the laser cavity 10 and is connected to a motor 22 arranged outside the laser cavity 10.

[0082] The preionization electrode 24 includes a dielectric tube, a preionization inner electrode disposed inside the dielectric tube, and one or more preionization outer electrodes disposed on the surface of the dielectric tube. The preionization electrode 24 is disposed along the length direction of the discharge electrode 11b at a position upstream of the discharge electrode 11b in the circulation direction of the laser gas.

[0083] The narrowband module 14 includes a prism 14a and a grating 14b. The prism 14a and the grating 14b are sequentially arranged on the optical path of the light emitted from the window 10a.

[0084] The gas supply device 42 includes a fluorine-containing gas bottle 40, an inert gas bottle 41, and a xenon gas bottle 41c. In the present disclosure, a KrF excimer laser device is exemplified, in which case the fluorine-containing gas bottle 40 contains a fluorine-containing gas composed of neon gas, 1.25% krypton gas, and 1% fluorine gas, and the inert gas bottle 41 contains an inert gas composed of neon gas and 1.25% krypton gas. By adjusting the total amount and partial pressure ratio of the gas supplied from the fluorine-containing gas bottle 40 and the inert gas bottle 41 to the laser cavity 10, the total cavity pressure and the fluorine concentration can be adjusted. For example, when the target pressure P (F2) after the fluorine-containing gas is injected into the laser cavity 10 in a substantially vacuum state is set to 30 kPa, and the target total pressure Pt after the inert gas is injected is set to 300 kPa, the fluorine concentration in the laser cavity 10 becomes 0.1%.

[0085] In order to stabilize the pulse energy E of the laser, a small amount of xenon gas is sometimes injected from the xenon gas bottle 41c into the laser cavity 10. The optimal concentration of xenon gas is about 10 ppm.

[0086] Valves V6, V7, and V7c are provided in the piping connected to the fluorine-containing gas bottle 40, the inert gas bottle 41, and the xenon gas bottle 41c, respectively. These pipings merge with a piping provided with a valve V1 and are connected to the gas supply port 10d of the laser cavity 10. The valve V1 is equivalent to the first valve in the present disclosure, and the piping provided with the valve V1 is equivalent to the first piping.

[0087] The exhaust device 43 includes a fluorine trap 43a and an exhaust pump 43b. A valve V10 is provided on the piping connected to the exhaust device 43, and the piping is connected to the gas exhaust port 10e of the laser cavity 10. The fluorine trap 43a removes at least fluorine from the laser gas exhausted from the laser cavity 10. The exhaust pump 43b is configured to exhaust the gas after passing through the fluorine trap 43a to the outside of the laser device 100, so that the inside of the laser cavity 10 can be made into a substantially vacuum state. Substantially vacuum is, for example, below 0.1 kPa.

[0088] The pressure gauge P3 is configured to measure the pressure inside the laser cavity 10 .

[0089] 1.3.2 Action

[0090] The processor 130 receives the setting data of the target value Et of the pulse energy E and the light emission trigger signal from the exposure device 200. The processor 130 sends the setting data of the charging voltage to the charger included in the power supply device according to the setting data of the target value Et of the pulse energy E. In addition, the processor 130 sends a trigger signal to the power supply device according to the light emission trigger signal. After receiving the trigger signal from the processor 130, the power supply device generates a pulse-shaped high voltage using the electric energy charged by the charger, and applies the high voltage between the discharge electrodes 11a and 11b.

[0091] After a high voltage is applied between the discharge electrodes 11a and 11b, a discharge is generated between the discharge electrodes 11a and 11b. This discharge is called a main discharge. The laser medium in the laser cavity 10 is excited by the energy of the main discharge and transitions to a high energy level. Then, when the excited laser medium transitions to a low energy level, light of a wavelength corresponding to the energy level difference is emitted.

[0092] The light generated in the laser cavity 10 is emitted to the outside of the laser cavity 10 through the windows 10a and 10b. The beam width of the light emitted from the window 10a of the laser cavity 10 is expanded in the H direction by the prism 14a, and then enters the grating 14b.

[0093] The light incident on the grating 14b is reflected by the multiple grooves of the grating 14b and diffracted in a direction corresponding to the wavelength of the light. The wavelength of the diffracted light incident on the grating 14b to the prism 14a is selected by making the incident angle of the light incident on the grating 14b consistent with the diffraction angle of the diffracted light of the desired wavelength. The prism 14a reduces the beam width of the diffracted light incident from the grating 14b in the H direction and returns the light to the laser cavity 10 through the window 10a.

[0094] The output coupling mirror 15 transmits a part of the light emitted from the window 10 b of the laser cavity 10 to output the light, and reflects the other part to return to the laser cavity 10 .

[0095] In this way, the light emitted from the laser cavity 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 discharge electrodes 11a and 11b. The light is narrowbanded each time it returns to the narrowband module 14. The light oscillated and narrowbanded in this way is output from the output coupling mirror 15 as laser light.

[0096] When the motor 22 rotates the cross flow fan 21, Figure 3 As shown by the arrow B in the middle, the laser gas flows and circulates inside the laser cavity 10. The discharge products generated by the discharge between the discharge electrodes 11a and 11b are removed from the discharge space by the flow of the laser gas before the next discharge, and the discharge space and its vicinity become a state with few discharge products, so that the discharge can be stable. The heat exchanger 23 discharges the heat energy of the laser gas that has become high temperature by the discharge to the outside of the laser cavity 10.

[0097] Immediately before the main discharge, a voltage is applied between the preionization outer electrode and the preionization inner electrode included in the preionization electrode 24, and a corona discharge is generated around the preionization electrode 24. Short-wavelength light is generated by the corona discharge. The short-wavelength light ionizes the xenon between the discharge electrodes 11a and 11b. The situation where xenon is ionized before the main discharge is called preionization. By preionization, a main discharge with little deviation can be generated in the longitudinal direction of the discharge electrodes 11a and 11b, and a stable laser output can be performed.

[0098] During the repeated discharge between the discharge electrodes 11a and 11b in the laser cavity 10, the impurities contained in the laser gas increase or the fluorine concentration decreases, so the laser gas is replaced or supplemented. For example, the steps for completely replacing the gas in the laser cavity 10 are as follows.

[0099] (1) The gas in the laser cavity 10 is exhausted by the exhaust device 43, so that the laser cavity 10 is in a substantially vacuum state.

[0100] (2) Fluorine-containing gas is injected into the laser cavity 10 from the fluorine-containing gas bottle 40 through the gas supply device 42 .

[0101] (3) A small amount of xenon gas is injected from the xenon gas bottle 41 c into the laser cavity 10 through the gas supply device 42 .

[0102] (4) Inert gas is injected from the inert gas bottle 41 into the laser cavity 10 by the gas supply device 42 .

[0103] 1.4 Issues of Comparative Example

[0104] Injecting a small amount of xenon gas has the effect of stabilizing the pulse energy E, but there are the following three problems. In order to solve these problems, the cost increases, so the use of xenon gas is sometimes abandoned.

[0105] (1) In addition to the fluorine-containing gas cylinder 40 and the inert gas cylinder 41 , additional equipment and piping are required for installing the xenon gas cylinder 41 c .

[0106] (2) Generally speaking, gas cylinders contain gases at a pressure of 10 MPa or more. When transporting such gas cylinders from their place of manufacture, special transport methods and permission from the authorities are required.

[0107] (3) When the total pressure in the laser cavity 10 is set to 300 kPa, the partial pressure of 10 ppm of xenon gas is 0.003 kPa. It is difficult to accurately measure such a small pressure and introduce it into the laser cavity 10 .

[0108] 2. Xenon gas supply using XeF2 crystal

[0109] 2.1 Structure

[0110] Figure 4 1 shows a mechanism for supplying xenon gas in the first embodiment. In order to supply xenon gas to the laser cavity 10, the buffer tank 47a and the XeF2 container 47b are connected to the gas supply port 10d via piping. Figure 4 In the figure, in order to show the typical flow direction of the gas in the pipe, an arrow is marked on each valve, but each valve may not be a check valve.

[0111] The buffer tank 47a is a sealable container connected to the laser cavity 10 via a pipe including a valve V1 and a pipe including a valve V15. The XeF2 container 47b is a sealable container connected to the buffer tank 47a via a pipe including a valve V2. The valve V2 is equivalent to the second valve in the present disclosure, and the pipe including the valve V2 is equivalent to the second pipe.

[0112] Figure 5 The XeF2 container 47b is shown in detail. The XeF2 container 47b contains XeF2 crystals 54. The XeF2 crystals 54 are sublimable solids and have a vapor pressure VP of about 0.5 kPa at 25°C.

[0113] The XeF2 container 47b is provided with a temperature sensor 51, a temperature regulator 52 and a pressure gauge P2. The temperature sensor 51 measures the temperature in the XeF2 container 47b, preferably measures the temperature T of the XeF2 crystal 54, and outputs the measurement result to the temperature controller 50. The temperature regulator 52 includes a heater, a cooler or both of them, and adjusts the temperature in the XeF2 container 47b to adjust the temperature T of the XeF2 crystal 54. The temperature controller 50 controls the temperature regulator 52 according to the measurement result of the temperature sensor 51 according to the control signal received from the processor 130. Thus, the vapor pressure VP of the XeF2 crystal 54 is adjusted. The pressure gauge P2 measures the air pressure in the XeF2 container 47b, and outputs the measurement result to the processor 130.

[0114] Figure 6 The table shows the relationship between the temperature T and the vapor pressure VP of the XeF2 crystal 54. The lowest value of the temperature range in which the temperature regulator 52 can adjust the temperature is set to T1, and the highest value is set to Tn. Figure 2 ) pre-stores data of the vapor pressure VP of the XeF2 crystal 54 at various temperatures T. The processor 130 can refer to the data to calculate a target value of the temperature T for obtaining the desired vapor pressure VP.

[0115] Refer again Figure 4 The buffer tank 47a and the XeF2 container 47b constitute a XeF2 vaporization space 47. The XeF2 vaporization space 47 is connected to the laser cavity 10 via a pipe including a valve V1 and a pipe including a valve V15.

[0116] The buffer tank 47a is connected to the exhaust device 43 via a pipe including a valve V3 and a pipe including a valve V15. The valve V3 is equivalent to the third valve in the present disclosure. The exhaust device 43 can exhaust so that the XeF2 gasification space 47 becomes a substantially vacuum state. The XeF2 gasification space 47 is made substantially vacuum, and the valves V3 and V15 are closed and temporarily standby, whereby the interior of the XeF2 gasification space 47 is filled with XeF2 gas of a pressure corresponding to the vapor pressure VP of the XeF2 crystal 54.

[0117] The XeF2 vaporization space 47 is connected to the gas supply device 42 via a pipe including a valve V4. Valve V4 is equivalent to the fourth valve in the present disclosure. If valves V4, V15 and V1 are opened, the laser cavity 10 and the gas supply device 42 are connected via the XeF2 vaporization space 47. When the fluorine-containing gas is supplied to the laser cavity 10, valve V6 is opened, and when the inert gas is supplied to the laser cavity 10, valves V7 and V9 are opened. Thus, the XeF2 gas in the XeF2 vaporization space 47 is introduced into the laser cavity 10 together with the gas supplied from the fluorine-containing gas bottle 40 or the inert gas bottle 41. The XeF2 gas introduced into the laser cavity 10 is easily dissociated by the discharge between the discharge electrodes 11a and 11b.

[0118] The pipe including valve V4 is connected to the buffer tank 47a in the XeF2 gasification space 47. In addition, if valve V2 is closed, the buffer tank 47a is cut off from the XeF2 container 47b. Therefore, if valve V2 is closed, valves V4, V15 and V1 are opened, the XeF2 gas introduced into the laser cavity 10 can be limited to the XeF2 gas in the buffer tank 47a.

[0119] In order to supply gas directly to the laser cavity 10 from the fluorine-containing gas bottle 40 or the inert gas bottle 41 without introducing XeF2 gas into the laser cavity 10, a piping including a valve V19 may also be used. The piping including the valve V19 may also be connected to the piping including the valve V1 instead of being directly connected to the laser cavity 10.

[0120] The XeF2 container 47b is connected to the gas supply device 42 via a pipe including a valve V5. The valve V5 is equivalent to the fifth valve in the present disclosure. During the period when the generation of XeF2 gas and the supply to the laser cavity 10 are not performed, the gas is filled into the XeF2 container 47b, thereby suppressing the gasification of the XeF2 crystal 54. It is preferred that the inert gas in the inert gas bottle 41 is filled into the XeF2 container 47b via the pipe including the valve V7 and the pipe including the valve V5. It is also possible to open the valve V2, not only to fill the XeF2 container 47b with inert gas, but also to fill the XeF2 gasification space 47 as a whole with inert gas. Furthermore, it is also possible to replace the valve V5 and fill the XeF2 gasification space 47 with inert gas via the valve V18.

[0121] exist Figure 4 1 shows a case where one gas supply device 42, one exhaust device 43, and one XeF2 vaporization space 47 are connected to one laser cavity 10, but the present disclosure is not limited thereto. One gas supply device 42, one exhaust device 43, and one XeF2 vaporization space 47 may also be connected to multiple laser cavities 10.

[0122] Regarding other aspects, the structure of the first embodiment is the same as that of the comparative example.

[0123] 2.2 Action

[0124] 2.2.1 Main Process

[0125] Figure 7 This is a flowchart showing the procedure of supplying xenon gas in the first embodiment.

[0126] In S100, the processor 130 performs preprocessing for supplying the laser gas together with the XeF2 gas to the laser cavity 10. For details of S100, refer to Figure 8 This will be described later.

[0127] In S200, the processor 130 controls various valves to generate XeF2 gas in the XeF2 container 47b. Fig. 9 This will be described later.

[0128] In S300, the processor 130 controls various valves to exhaust the gas in the laser cavity 10. For details of S300, refer to Fig.10 This will be described later.

[0129] In S400, the processor 130 controls various valves so that the laser gas and the XeF2 gas are supplied into the laser cavity 10. Fig.11 This will be described later.

[0130] In S500, the processor 130 controls various valves to fill the XeF2 container 47b with inert gas. Fig.12 This will be described later.

[0131] In S600, the processor 130 performs post-processing after the laser gas is supplied to the laser cavity 10. For details of S600, refer to Fig.13 This will be described later.

[0132] After S600 , the processor 130 ends the processing of this flowchart.

[0133] 2.2.2 Preprocessing

[0134] Figure 8 This is a flowchart showing the details of the pre-processing in the first embodiment. Figure 8 The processing shown is equivalent to Figure 7 The S100 subroutine.

[0135] In S101 , the processor 130 obtains the following data.

[0136] ·Target pressure P(F2) after fluorine-containing gas injection

[0137] Target total pressure Pt

[0138] Laser cavity volume Vc

[0139] Target xenon concentration Ct

[0140] Buffer tank volume Vb

[0141] The target total pressure Pt and the target xenon concentration Ct are determined according to the required laser performance. The target pressure P(F2) after the fluorine-containing gas is injected is obtained according to the fluorine concentration in the laser cavity 10 set as the target and the target total pressure Pt. The laser cavity volume Vc and the buffer tank volume Vb can be pre-stored in the memory 131.

[0142] In S102, the processor 130 calculates the target vapor pressure VPt of the XeF2 crystal 54. When all the XeF2 gas in the buffer tank 47a is introduced into the laser cavity 10, the XeF2 concentration Cf in the laser cavity 10 is given by the following equation 1.

[0143] Cf=(VPt·Vb) / (Pt·Vc)…Formula 1

[0144] According to Formula 1, the target vapor pressure VPt may be set to the following value.

[0145] VPt=Pt·Vc·Cf / Vb…Formula 2

[0146] Here, when the XeF 2 gas introduced into the laser cavity 10 is completely dissociated into xenon gas and fluorine gas, the XeF 2 concentration Cf may be made consistent with the target xenon concentration Ct. Therefore, the target vapor pressure VPt is given by the following formula.

[0147] VPt=Pt·Vc·Ct / Vb

[0148] For correction when the XeF2 concentration Cf calculated by equation 1 is inconsistent with the actual xenon concentration Cx, refer to Fig.14 This will be described later.

[0149] In S103, the processor 130 calculates a target value for the temperature T of the XeF2 crystal 54. The target value for the temperature T of the XeF2 crystal 54 can be calculated based on the target vapor pressure VPt and Figure 6 Calculated based on the data shown.

[0150] In S104, the processor 130 obtains the temperature from the temperature sensor 51 (refer to Figure 5 ) obtain the measured value of the temperature T of the XeF2 crystal 54.

[0151] In S105, the processor 130 starts to control the temperature of the XeF2 crystal 54 by the temperature regulator 52. The temperature control is performed by the temperature controller 50 and lasts until Fig.13 The process continues until it stops in S602.

[0152] In S106, the processor 130 starts the operation of the exhaust pump 43b. At this point, the operation of exhausting the laser cavity 10 and the buffer tank 47a is not performed. The operation of exhausting these spaces is switched on and off by opening and closing the valve. The operation of the exhaust pump 43b continues until Fig.13 The process stops in S601.

[0153] After S106, the processor 130 ends the processing of this flowchart and returns to Figure 7 Processing shown.

[0154] 2.2.3 Processing of XeF2 gas generated in XeF2 container 47b

[0155] Fig. 9 1 is a flowchart showing details of a process for generating XeF 2 gas in the XeF 2 container 47 b in the first embodiment. Fig. 9 The processing shown is equivalent to Figure 7 The S200 subroutine.

[0156] In S201, the processor 130 opens the valves V3, V15, and V2, thereby exhausting the interiors of the buffer tank 47a and the XeF2 container 47b.

[0157] In S202, the processor 130 waits for a certain time. The pressure inside the buffer tank 47a and the XeF2 container 47b during the waiting time corresponds to the first pressure in the present disclosure. The first pressure is preferably a substantially vacuum state, but is not limited thereto, as long as it is a pressure lower than the target vapor pressure VPt.

[0158] In S203, the processor 130 closes valves V15 and V3. Thus, the XeF2 vaporization space 47 is cut off from the exhaust device 43. Furthermore, XeF2 gas begins to be generated in the XeF2 vaporization space 47. The temperature T of the XeF2 crystal 54 is controlled to a temperature corresponding to the target vapor pressure VPt. The target vapor pressure VPt is equivalent to the second pressure in the present disclosure.

[0159] In S204, the processor 130 determines whether the gas pressure obtained from the pressure gauge P2 of the XeF2 container 47b has reached the target vapor pressure VPt. Fig. 9 However, the condition is not to make it completely the same, but it is sufficient to determine whether it is within a predetermined error range. Fig.11 and Fig.17 The same is true in Chinese.

[0160] When the gas pressure of the XeF2 container 47b has not reached the target vapor pressure VPt (S204: No), the processor 130 advances the process to S205. In S205, the processor 130 waits for a certain period of time and then returns the process to S204.

[0161] When the gas pressure of the XeF2 container 47b reaches the target vapor pressure VPt (S204: Yes), the processor 130 advances the process to S206. In S206, the processor 130 closes the valve V2. Thus, the buffer tank 47a and the XeF2 container 47b are disconnected.

[0162] After S206, the processor 130 ends the processing of this flowchart and returns to Figure 7 Processing shown.

[0163] 2.2.4 Treatment of exhaust gas in laser cavity 10

[0164] Fig.10 1 is a flowchart showing details of the process of exhausting the gas in the laser cavity 10 in the first embodiment. Fig.10 The processing shown is equivalent to Figure 7 The S300 subroutine.

[0165] In S301 , the processor 130 opens the valve V10 , thereby starting exhaust of the interior of the laser cavity 10 .

[0166] In S302 , the processor 130 determines whether the pressure in the laser cavity 10 obtained from the pressure gauge P3 is 0.1 kPa or less.

[0167] When the pressure in the laser cavity 10 is not less than 0.1 kPa (S302: No), the processor 130 advances the process to S303. In S303, the processor 130 waits for a certain period of time and then returns the process to S302.

[0168] When the pressure in the laser cavity 10 is 0.1 kPa or less (S302: Yes), the processor 130 advances the process to S304. In S304, the processor 130 closes the valve V10. Thus, the laser cavity 10 and the exhaust device 43 are disconnected.

[0169] After S304, the processor 130 ends the processing of this flowchart and returns to Figure 7 Processing shown.

[0170] 2.2.5 Processing of supplying gas into the laser cavity 10

[0171] Fig.11 1 is a flowchart showing details of the process of supplying gas into the laser cavity 10 in the first embodiment. Fig.11 The processing shown is equivalent to Figure 7 The S400 subroutine.

[0172] In S401 , the processor 130 opens the valves V1 , V15 , V4 , and V6 , thereby supplying the fluorine-containing gas in the fluorine-containing gas bottle 40 into the laser cavity 10 together with the XeF 2 gas in the buffer tank 47 a .

[0173] In S402 , the processor 130 determines whether the pressure in the laser cavity 10 obtained from the pressure gauge P3 has reached the target pressure P ( F2 ) after the fluorine-containing gas is injected.

[0174] When the pressure in the laser cavity 10 has not reached the target pressure P(F2) (S402: No), the processor 130 advances the process to S403. In S403, the processor 130 waits for a certain period of time and then returns the process to S402.

[0175] When the pressure in the laser cavity 10 reaches the target pressure P(F2) (S402: YES), the processor 130 advances the process to S404. In S404, the processor 130 closes the valve V6. Thus, the supply of the fluorine-containing gas from the gas supply device 42 to the buffer tank 47a is stopped.

[0176] In S405, the processor 130 opens valves V7 and V9. Thus, the inert gas in the inert gas bottle 41 is supplied to the laser cavity 10 via the buffer tank 47a. When the XeF2 gas remains in the buffer tank 47a, the inert gas is supplied to the laser cavity 10 together with the XeF2 gas.

[0177] In S406 , the processor 130 determines whether the pressure in the laser cavity 10 obtained from the pressure gauge P3 has reached the target total pressure Pt of the laser cavity 10 .

[0178] When the pressure in the laser cavity 10 has not reached the target total pressure Pt (S406: No), the processor 130 advances the process to S407. In S407, the processor 130 waits for a certain period of time and then returns the process to S406.

[0179] When the pressure in the laser cavity 10 reaches the target total pressure Pt (S406: YES), the processor 130 advances the process to S408. In S408, the processor 130 closes valves V4, V9, and V7. Thus, the supply of the inert gas from the gas supply device 42 to the buffer tank 47a is stopped.

[0180] In S409 , the processor 130 closes the valves V15 and V1 , thereby cutting off the connection between the laser cavity 10 and the buffer tank 47 a .

[0181] After S409, the processor 130 ends the processing of this flowchart and returns to Figure 7 Processing shown.

[0182] 2.2.6 Processing of filling the XeF2 container 47b with inert gas

[0183] Fig.12 1 is a flowchart showing details of the process of filling the XeF 2 container 47 b with the inert gas in the first embodiment. Fig.12 The processing shown is equivalent to Figure 7 The S500 subroutine.

[0184] S501~S503 and Fig. 9 The same as S201 to S203 of . Thus, the interiors of the buffer tank 47a and the XeF2 container 47b are exhausted.

[0185] In S504, the processor 130 opens the valves V7 and V5. As a result, the inert gas in the inert gas bottle 41 is supplied to the XeF2 container 47b and the buffer tank 47a.

[0186] In S505, the processor 130 determines whether the gas pressure obtained from the pressure gauge P2 of the XeF2 container 47b is equal to or higher than 100 kPa.

[0187] When the gas pressure of the XeF2 container 47b is not equal to or higher than 100 kPa (S505: No), the processor 130 advances the process to S506. In S506, the processor 130 waits for a certain period of time and then returns the process to S505.

[0188] When the gas pressure of the XeF2 container 47b becomes 100 kPa or more (S505: Yes), the processor 130 advances the process to S507. In S507, the processor 130 closes the valves V2, V5, and V7. Thus, the filling of the XeF2 vaporization space 47 with the inert gas from the gas supply device 42 is completed.

[0189] After S507, the processor 130 ends the processing of this flowchart and returns to Figure 7 Processing shown.

[0190] 2.2.7 Post-processing

[0191] Fig.13 This is a flowchart showing the details of the post-processing in the first embodiment. Fig.13 The processing shown is equivalent to Figure 7 The S600 subroutine.

[0192] In S601, the processor 130 stops the operation of the exhaust pump 43b. In S602, the processor 130 stops the temperature control of the XeF2 crystal 54. In S603, the processor 130 starts the discharge between the discharge electrodes 11a and 11b. Thus, the XeF2 gas is dissociated into xenon gas and fluorine gas. The discharge between the discharge electrodes 11a and 11b can be a discharge for outputting laser light to the exposure device 200, or a discharge performed in a state where the shutter (not shown) between the laser device 100 and the exposure device 200 is closed.

[0193] After S603, the processor 130 ends the processing of this flowchart and returns to Figure 7 Processing shown.

[0194] 2.3 Correction of XeF2 concentration Cf

[0195] The above description is based on the premise that the XeF2 concentration Cf calculated by equation 1 is consistent with the actual xenon concentration Cx, but there may be a situation where they are inconsistent. For example, there may be a situation where a part of the XeF2 gas introduced into the laser cavity 10 is not dissociated, or even if it is temporarily dissociated, it is recombined.

[0196] Fig.14 An example of the relationship between the XeF2 concentration Cf and the actual xenon concentration Cx is shown. The XeF2 concentration Cf can also be corrected based on this relationship. For example, the XeF2 concentration Cf calculated by Formula 1 and the actual xenon concentration Cx can be approximated by the following formula using a proportional constant A.

[0197] Cx=A·Cf

[0198] In this case, according to Formula 2, the target vapor pressure VPt is given by the following formula.

[0199] VPt=Pt·Vc·(Ct / A) / Vb

[0200] The xenon concentration Cx is measured to obtain Fig.14 There are methods for analyzing the relationship shown in the figure, such as a method of analyzing the sample gas by a mass spectrometer, and a method of analyzing the luminous intensity of light with a wavelength of 354nm related to the xenon concentration Cx by splitting the discharge light between electrodes by a spectrometer. 354nm is equivalent to the wavelength of the luminous line of XeF. This measurement can also be performed before the laser device 100 is shipped, so that the memory 131 stores Fig.14 In addition, the laser device 100 may be equipped with a mass spectrometer or a spectrometer to measure the xenon concentration Cx at any time.

[0201] Fig.15 An example of the relationship between XeF2 concentration Cf and pulse energy deviation is shown. Pulse energy deviation is, for example, the standard deviation of the pulse energy E of the laser divided by the average value. The smaller the pulse energy deviation, the better the stability of the pulse energy E. By placing an energy sensor (not shown) on the optical path of the laser, the pulse energy E can be measured. It can also be based on Fig.15 The optimum value Cfo of the XeF2 concentration Cf is determined by this relationship. In this case, according to equation 2, the target vapor pressure VPt is given by the following equation.

[0202] VPt=Pt·Vc·Cfo / Vb

[0203] 2.4 Function

[0204] In the first embodiment, the laser device 100 includes: a laser cavity 10, which accommodates fluorine-containing laser gas; a pair of discharge electrodes 11a and 11b, which are arranged in the laser cavity 10; a gas supply port 10d, which is arranged in the laser cavity 10; and a XeF2 crystal 54, which is arranged in a XeF2 vaporization space 47 connected to the gas supply port 10d and is vaporized.

[0205] Thus, the XeF 2 gas generated from the XeF 2 crystal 54 is introduced into the laser cavity 10 , and the XeF 2 gas is dissociated into xenon gas and fluorine gas by discharge, so that even without using the xenon gas bottle 41 c , the pulse energy E of the laser can be stabilized.

[0206] According to the first embodiment, the laser device 100 further includes a temperature regulator 52 that regulates the temperature T of the XeF 2 crystal 54 .

[0207] Thus, by adjusting the temperature T of the XeF 2 crystal 54 , the supply amount of the XeF 2 gas can be adjusted, and therefore the xenon concentration Cx in the laser cavity 10 can be adjusted to an optimal range.

[0208] According to the first embodiment, the laser device 100 further includes a processor 130 that controls the temperature regulator 52 based on the target total pressure Pt and the target xenon concentration Ct of the laser gas in the laser cavity 10 .

[0209] Thus, the temperature regulator 52 can be controlled according to the operating conditions of the laser device 100 to adjust the xenon concentration Cx with high accuracy.

[0210] According to the first embodiment, the processor 130 determines the target vapor pressure VPt of the XeF 2 crystal 54 based on the target total pressure Pt and the target xenon concentration Ct, and controls the temperature regulator 52 based on the target vapor pressure VPt.

[0211] Thus, by determining the target vapor pressure VPt, the amount of XeF 2 gas generated can be adjusted with high accuracy.

[0212] According to the first embodiment, the XeF 2 vaporization space 47 communicates with the laser cavity 10 via the first pipe including the valve V1 .

[0213] Thus, during the period of vaporizing the XeF2 crystal 54, the valve V1 is used to cut off the XeF2 vaporization space 47 and the laser cavity 10, thereby limiting the amount of XeF2 gas generated, thereby making the xenon concentration Cx in the laser cavity 10 close to the optimal range.

[0214] According to the first embodiment, the XeF2 vaporization space 47 includes: a buffer tank 47a, which is connected to the laser cavity 10 via a first pipe including a valve V1; and a XeF2 container 47b, which is connected to the buffer tank 47a via a second pipe including a valve V2 and accommodates a XeF2 crystal 54.

[0215] Thus, the XeF 2 vaporization space 47 is divided into the XeF 2 container 47 b and the buffer tank 47 a , and the XeF 2 gas in the buffer tank 47 a is supplied to the laser cavity 10 , thereby enabling the supply amount of the XeF 2 gas to be adjusted with high precision.

[0216] According to the first embodiment, the laser device 100 has an exhaust device 43 for exhausting the XeF2 vaporization space 47, a valve V3 between the XeF2 vaporization space 47 and the exhaust device 43, and a processor 130. The processor 130 opens the valve V3 and controls the exhaust device 43 so that the pressure in the XeF2 vaporization space 47 becomes the first pressure; closes the valve V3 and controls the temperature regulator 52 so that the vapor pressure VP of the XeF2 crystal 54 becomes a target vapor pressure VPt higher than the first pressure.

[0217] Thus, by exhausting the XeF 2 vaporization space 47 , the amount of XeF 2 gas generated in the XeF 2 vaporization space 47 can be adjusted with high accuracy.

[0218] According to the first embodiment, the XeF 2 vaporization space 47 is communicated with the fluorine-containing gas bottle 40 or the inert gas bottle 41 that stores the laser gas.

[0219] Thus, the XeF 2 gas generated in the XeF 2 vaporization space 47 can be supplied to the laser cavity 10 together with the laser gas supplied from a gas cylinder having a higher pressure than that of the laser cavity 10 .

[0220] According to the first embodiment, a valve V4 is disposed in the piping connecting the buffer tank 47a and the fluorine-containing gas bottle 40 or the inert gas bottle 41. After the pressure in the XeF2 vaporization space 47 reaches the target vapor pressure VPt, the processor 130 closes the valve V2 and opens the valves V1 and V4, thereby supplying the gas in the buffer tank 47a to the laser cavity 10 together with the laser gas supplied from the fluorine-containing gas bottle 40 or the inert gas bottle 41.

[0221] Thus, by supplying laser gas from the gas cylinder to the buffer tank 47a, the XeF2 gas in the buffer tank 47a is supplied to the laser cavity 10 without waste, so the supply amount of the XeF2 gas to the laser cavity 10 can be adjusted with high precision.

[0222] According to the first embodiment, the valve V5 is disposed in the pipe connecting the XeF 2 container 47 b and the fluorine-containing gas cylinder 40 or the inert gas cylinder 41 .

[0223] Thus, during the period when the XeF 2 crystal 54 is not used, the XeF 2 container 47 b is filled with the gas ( S504 to S506 ), and the vaporization of the XeF 2 crystal 54 can be suppressed.

[0224] According to the first embodiment, the XeF 2 container 47 b is filled with an inert gas supplied via the valve V5 .

[0225] Thus, during the period when the XeF 2 crystal 54 is not used, the XeF 2 container 47 b is filled with the inert gas ( S504 to S506 ), thereby suppressing the reaction of the gas.

[0226] Regarding other aspects, the first embodiment is the same as the comparative example.

[0227] 3. Dissociation of XeF2 gas based on discharge reactor

[0228] 3.1 Structure

[0229] Fig.16 The structure of the buffer tank 47a in the second embodiment is shown. The buffer tank 47a includes an electrode 62 connected to the power supply 60 via a feedthrough 63. The power supply 60 is preferably an AC power supply or a pulse power supply. A switch 61 is arranged between the feedthrough 63 and the power supply 60. The power supply 60 and the switch 61 are controlled by the processor 130. The conductive material constituting the buffer tank 47a is connected to the ground potential. The electrode 62 is equivalent to the discharge reactor in the present disclosure.

[0230] XeF2 gas flows into the buffer tank 47a through valve V2. The gas inside the buffer tank 47a is supplied to the laser cavity 10 through valve V15. Therefore, it is possible to generate Fig.16 The length direction of the electrode 62 may be substantially consistent with the direction of the gas flow. In order to efficiently dissociate the XeF2 gas, a plurality of buffer tanks 47a may be configured in one laser device 100, and discharge reactors may be provided in each of the plurality of buffer tanks 47a.

[0231] Regarding other aspects, the structure of the second embodiment is the same as that of the first embodiment.

[0232] 3.2 Action

[0233] Fig.17 1 is a flowchart showing details of a process for generating XeF 2 gas in the XeF 2 container 47 b in the second embodiment. Fig.17 The processing shown is equivalent to Figure 7 In the second embodiment, the XeF 2 gas generated in the XeF 2 container 47 b is dissociated by the discharge reactor in the buffer tank 47 a.

[0234] Processing and reference of S201 to S206 Fig. 9 The process described above is the same, and the XeF 2 container 47 b and the buffer tank 47 a are cut off from each other in a state where the interiors of the XeF 2 container 47 b and the buffer tank 47 a are filled with the XeF 2 gas at the target vapor pressure VPt.

[0235] In S207, the processor 130 turns on the switch 61. As a result, discharge occurs between the electrode 62 and the conductive material of the grounded buffer tank 47a, and the dissociation of the XeF2 gas starts.

[0236] In S208 , processor 130 waits until a predetermined time Tw elapses. In S209 , processor 130 turns off switch 61 .

[0237] After S209, the processor 130 ends the processing of this flowchart and returns to Figure 7 Processing shown.

[0238] 3.3 Function

[0239] According to the second embodiment, the buffer tank 47a includes the electrode 62 as a discharge reactor for dissociating the XeF2 gas.

[0240] Thus, the XeF 2 gas can be supplied to the laser cavity 10 in a state where it is dissociated into xenon gas and fluorine gas, and thus a stable pulse energy E can be obtained from the first discharge after the gas supply.

[0241] Regarding other aspects, the second embodiment is the same as the first embodiment.

[0242] 4. Gas regeneration device 49 including buffer tank 47a

[0243] 4.1 Structure

[0244] Fig.18 The mechanism for supplying xenon gas in the third embodiment is shown. The mechanism includes a gas regeneration device 49. The piping including the valve V10 is branched into a piping including the valve V11 and a piping including the valve V12. The laser gas after passing through the valve V11 flows toward the exhaust device 43, and the gas after passing through the valve V12 flows toward the gas regeneration device 49.

[0245] The gas regeneration device 49 includes a fluorine trap 44, a refining column 45, a booster pump 46, and a regeneration gas tank 48. The fluorine trap 44 removes at least fluorine from the laser gas. The refining column 45 includes a filter for removing impurities. The laser gas after passing through the refining column 45 is called regeneration gas. The booster pump 46 delivers the regeneration gas at a higher pressure than the inside of the laser cavity 10.

[0246] The regeneration gas sent from the booster pump 46 and after passing through the valve V13 passes through either the first path or the second path. The first path is a path that passes through the valve V14, the buffer tank 47a, and the valve V15 in sequence. The second path branches from the first path upstream of the valve V14 in the first path, bypasses the buffer tank 47a, and merges with the first path downstream of the valve V15 in the first path. A valve V16 is arranged in the second path.

[0247] The regeneration gas tank 48 is disposed between the valve V15 and the valve V1. In the third embodiment, the valve V3 is used when exhausting the regeneration gas tank 48. When exhausting the buffer tank 47a, a pipe including a valve V3a is used instead of the valve V3.

[0248] A pipe including a valve V7b is connected to the inert gas bottle 41 instead of the valves V7 and V9. The inert gas contained in the inert gas bottle 41 is supplied to the buffer tank 47a through the valve V4. A helium bottle 41a is connected to the pipe including the valve V7 instead of the inert gas bottle 41. The helium contained in the helium bottle 41a is supplied to the XeF2 container 47b through the valve V5. In this way, the inert gas filled in the XeF2 container 47b may also be helium, which is a gas different from the gas contained in the laser gas supplied to the laser cavity 10. In the first and second embodiments, a structure in which helium is filled in the XeF2 container 47b can also be adopted.

[0249] The third embodiment is the same as the first embodiment in other respects. Alternatively, in the third embodiment, a buffer tank 47a including a discharge reactor may be provided similarly to the second embodiment.

[0250] 4.2 Xenon Addition Operation in Gas Regeneration Device 49

[0251] When filling the laser cavity 10 with laser gas, the regeneration gas regenerated in the gas regeneration device 49 is used instead of the new gas supplied from the gas supply device 42, thereby saving resources. However, the gas regeneration device 49 includes a fluorine trap 44, and the regeneration gas contains almost no fluorine gas. Therefore, the fluorine concentration in the laser cavity 10 is reduced by simply supplying the regeneration gas directly to the laser cavity 10. Therefore, when the regeneration gas is supplied to the laser cavity 10, a fluorine-containing gas is added.

[0252] Since xenon gas is not included in the fluorine-containing gas, when the supply of the regeneration gas and the addition of the fluorine-containing gas are repeated, the xenon concentration Cx in the laser cavity 10 decreases. Therefore, by adding xenon gas according to the amount of the fluorine-containing gas added, the decrease in the xenon concentration Cx can be suppressed. The method for adjusting the amount of xenon gas added is the same as that in the first embodiment.

[0253] 4.3 Xenon addition in new gas supply

[0254] Operation and reference of xenon addition when new gas is supplied from the gas supply device 42 to the laser cavity 10 Figure 7 to Figure 13 and Fig.17 The operation described is the same. However, the following aspects are changed.

[0255] (1) Replace Fig. 9 and Fig.17S201 and S203 or Fig.12 In S501 and S503 of the embodiment, the valves V3 and V15 are opened and closed together, whereas in the third embodiment, the valve V3a is opened and closed.

[0256] (2) Replace Fig.10 The valve V10 is opened and closed in S301 and S304 of the embodiment, whereas the valves V10 and V11 are opened and closed together in the third embodiment.

[0257] (3) Replace Fig.11 In S405 and S408 of the embodiment, valves V7 and V9 are opened and closed together, whereas in the third embodiment, valve V7b is opened and closed.

[0258] 4.4 Function

[0259] According to the third embodiment, the inert gas filled in the XeF 2 container 47 b is a gas different from the gas included in the laser gas supplied to the laser cavity 10 .

[0260] Since the inert gas filled in the XeF 2 container 47 b is exhausted ( S201 to S203 ), it is not necessary to use the same gas as the gas included in the laser gas, and a cheaper gas can be used.

[0261] According to the third embodiment, the laser device 100 further includes a gas regeneration device 49 for purifying and pressurizing the laser gas exhausted from the laser cavity 10 , and the buffer tank 47 a is disposed on the path of the gas regeneration device 49 .

[0262] Thus, when the fluorine-containing gas is supplied to the laser cavity 10 together with the regeneration gas whose fluorine gas concentration is reduced in the gas regeneration device 49 , the reduction in the xenon concentration Cx can be compensated.

[0263] According to the third embodiment, the gas regeneration device 49 includes a first path and a second path, wherein the first path passes through a buffer tank 47a, and the second path branches from the first path upstream of the buffer tank 47a in the first path, avoids the buffer tank 47a, and merges with the first path downstream of the buffer tank 47a in the first path.

[0264] Thus, when it is not necessary to add XeF 2 gas to the regeneration gas, the regeneration gas can be supplied to the laser cavity 10 without passing through the buffer tank 47 a .

[0265] Regarding other aspects, the third embodiment is the same as the first or second embodiment.

[0266] 5. XeF2 crystal 54 arranged in the flow path of the airflow generated by the cross flow fan 21

[0267] 5.1 Structure

[0268] Fig.19 The structure of a part of the laser device 100 according to the fourth embodiment as viewed in the -V direction is shown. Fig. 20 A partial structure of the laser device 100 according to the fourth embodiment as viewed in the Z direction is shown.

[0269] In the fourth embodiment, a filter case 70 is connected to the laser cavity 10. The filter case 70 accommodates a filter 71. The filter case 70 communicates with the interior of the laser cavity 10 via a gas outlet 10e provided in a wall substantially in the center in the longitudinal direction of the discharge electrode 11a of the laser cavity 10 and an in-wall gas path 10f provided in walls at both ends in the longitudinal direction of the discharge electrode 11a of the laser cavity 10. The in-wall gas path 10f opens to the interior of the laser cavity 10 at a gas supply port 10d located near the window 10a or 10b.

[0270] The laser gas flows in a gas flow path from the gas outlet 10e through the filter housing 70 and the in-wall gas path 10f to the gas supply port 10d using the airflow generated by the crossflow fan 21. The XeF2 crystal 54 is disposed in the gas flow path. The gas flow path is an example of the XeF2 gasification space in the present disclosure. Preferably, the XeF2 crystal 54 is disposed downstream of the filter 71 in the gas flow path.

[0271] Alternatively, the XeF2 crystal 54 may be disposed at any location within the laser cavity 10. In this case, the XeF2 vaporization space in the present disclosure may not be a container different from the laser cavity 10, and the space within the laser cavity 10 is also equivalent to the XeF2 vaporization space in the present disclosure.

[0272] A temperature sensor 51 and a temperature regulator 52 are arranged on the wall surface of the gas flow path and near the XeF2 crystal 54. The processor 130 (see Figure 2 ) The temperature regulator 52 is controlled according to the temperature T of the XeF2 crystal 54 measured by the temperature sensor 51.

[0273] The laser cavity 10 is also connected to Figure 2 The gas supply device 42 and the exhaust device 43 are shown. However, the gas supply device 42 may not include the xenon gas cylinder 41c.

[0274] 5.2 Action

[0275] There are the following two methods for adjusting the xenon concentration Cx in the laser cavity 10 to an optimal range.

[0276] In the first method, first, after exhausting the laser cavity 10 through the exhaust device 43 to make it substantially vacuum, all valves connected to the outside of the laser cavity 10 are closed. Then, XeF2 gas is generated from the XeF2 crystal 54. After the pressure in the laser cavity 10 reaches the vapor pressure VP of the XeF2 crystal 54, laser gas of a target total pressure Pt is introduced into the laser cavity 10 through the gas supply device 42. When the XeF2 concentration VP / Pt in the laser cavity 10 at this time becomes X times the optimal value, the laser gas in the laser cavity 10 is further exhausted until the pressure becomes Pt / X. Thus, the amount of XeF2 gas in the laser cavity 10 is adjusted. When the first method is used, the temperature sensor 51 and the temperature regulator 52 may not be provided.

[0277] In the second method, first, after exhausting the laser cavity 10 by the exhaust device 43 to make it substantially vacuum, laser gas is supplied into the laser cavity 10 by the gas supply device 42 so that the pressure in the laser cavity 10 becomes the first set pressure Pi. Next, the temperature regulator 52 is controlled so that the vapor pressure VP of the XeF2 crystal 54 becomes the second set pressure Pj higher than the first set pressure Pi, and the XeF2 gas partial pressure when waiting for a sufficient time becomes Pj-Pi. The first set pressure Pi and the second set pressure Pj are set to obtain the desired XeF2 gas partial pressure, thereby adjusting the amount of XeF2 gas in the laser cavity 10.

[0278] 5.3 Function

[0279] According to the fourth embodiment, the laser device 100 further comprises a cross-flow fan 21, a gas outlet 10e disposed in the laser cavity 10, and a gas flow path. The cross-flow fan 21 is disposed in the laser cavity 10 to circulate the laser gas in the laser cavity 10 in the laser cavity 10. The gas flow path utilizes the airflow generated by the cross-flow fan 21 to return the laser gas discharged from the laser cavity 10 via the gas outlet 10e to the laser cavity 10 via the gas supply port 10d. The XeF2 crystal 54 is disposed in the gas flow path.

[0280] Thus, it is possible to easily obtain a device for supplying the XeF 2 gas generated from the XeF 2 crystal 54 to the laser cavity 10 .

[0281] According to the fourth embodiment, the laser device 100 further includes a filter 71 disposed in the gas flow path. The XeF2 crystal 54 is disposed downstream of the filter 71 in the gas flow path.

[0282] Thus, by arranging the XeF 2 crystal 54 downstream of the filter 71 , it is possible to suppress the adhesion of impurities and dust to the surface of the XeF 2 crystal 54 and make it difficult to generate XeF 2 gas.

[0283] According to the fourth embodiment, the laser device 100 has an exhaust device 43 for exhausting the laser cavity 10, a gas supply device 42 for supplying laser gas into the laser cavity 10, and a processor 130. The processor 130 controls the exhaust device 43 to exhaust the laser cavity 10, and after the pressure in the laser cavity 10 reaches the vapor pressure VP of the XeF2 crystal 54, controls the gas supply device 42 to supply laser gas into the laser cavity 10, and further controls the exhaust device 43 to exhaust a part of the laser gas from the laser cavity 10, thereby adjusting the amount of XeF2 gas in the laser cavity 10.

[0284] Thus, even when a large amount of XeF 2 gas is generated, the amount of XeF 2 gas in the laser cavity 10 can be adjusted by exhausting a portion of the laser gas.

[0285] According to the fourth embodiment, the laser device 100 has a temperature regulator 52 for regulating the temperature T of the XeF2 crystal 54, a gas supply device 42 for supplying laser gas into the laser cavity 10, and a processor 130. The processor 130 controls the gas supply device 42 to supply laser gas into the laser cavity 10 until the pressure in the laser cavity 10 becomes a first set pressure Pi, and controls the temperature regulator 52 so that the vapor pressure VP of the XeF2 crystal 54 becomes a second set pressure Pj higher than the first set pressure Pi, thereby adjusting the amount of the XeF2 gas in the laser cavity 10.

[0286] Thus, the amount of XeF 2 gas generated corresponds to the difference between the first set pressure Pi and the second set pressure Pj, and thus the amount of XeF 2 gas generated can be adjusted.

[0287] Regarding other aspects, the fourth embodiment is the same as the first embodiment.

[0288] 6. Others

[0289] The above description is not intended to be limiting, but is intended to be a simple illustration. Therefore, those skilled in the art will appreciate that changes can be made to the embodiments of the present disclosure without departing from the claims. In addition, those skilled in the art will appreciate that the embodiments of the present disclosure can be used in combination.

[0290] Unless explicitly stated otherwise, the terms used in this specification and claims as a whole should be interpreted as "non-limiting" terms. For example, terms such as "including", "having", "having", and "having" should be interpreted as "excluding the existence of structural elements other than the structural elements to be recorded". In addition, the modifier "one" should be interpreted as meaning "at least one" or "one or more". In addition, terms such as "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 as also including combinations of them and parts other than "A", "B", and "C".

Claims

1. A laser device, comprising: a laser cavity containing a laser gas containing fluorine; a pair of discharge electrodes disposed in the laser cavity; a gas supply port disposed in the laser cavity; and The XeF2 crystal is arranged in the XeF2 vaporization space communicating with the gas supply port and is vaporized.

2. The laser device according to claim 1, wherein: The laser device further includes a temperature regulator for regulating the temperature of the XeF2 crystal.

3. The laser device according to claim 2, wherein: The laser device further includes a processor that controls the temperature regulator according to a target total pressure and a target xenon concentration of the laser gas in the laser cavity.

4. The laser device according to claim 3, wherein: The processor determines a target vapor pressure of the XeF2 crystal according to the target total pressure and the target xenon concentration, and controls the temperature regulator according to the target vapor pressure.

5. The laser device according to claim 2, wherein: The XeF 2 vaporization space is connected to the laser cavity via a first pipe including a first valve.

6. The laser device according to claim 5, wherein: The XeF2 gasification space comprises: a buffer tank connected to the laser cavity via the first pipe; and A XeF2 container is communicated with the buffer tank via a second pipe including a second valve, and contains the XeF2 crystals.

7. The laser device according to claim 6, wherein: The laser device also has: An exhaust device for exhausting the XeF2 gasification space; A third valve between the XeF2 gasification space and the exhaust device; as well as processor, The processor opens the third valve and controls the exhaust device so that the pressure in the XeF2 vaporization space becomes the first pressure. The processor closes the third valve and controls the temperature regulator so that the vapor pressure of the XeF 2 crystal becomes a second pressure higher than the first pressure.

8. The laser device according to claim 7, wherein: The XeF2 gasification space is communicated with a gas cylinder containing laser gas.

9. The laser device according to claim 8, wherein: A fourth valve is disposed on the pipe connecting the buffer tank and the gas cylinder. After the pressure in the XeF2 vaporization space reaches the second pressure, the processor closes the second valve. The processor opens the fourth valve and the first valve, thereby supplying the gas in the buffer tank to the laser cavity together with the laser gas supplied from the gas cylinder.

10. The laser device according to claim 8, wherein: A fifth valve is disposed on the pipe connecting the XeF2 container and the gas cylinder.

11. The laser device according to claim 10, wherein: The XeF2 container is filled with the inert gas supplied through the fifth valve.

12. The laser device according to claim 11, wherein: The inert gas filled in the XeF 2 container is a gas different from a gas included in the laser gas supplied to the laser cavity.

13. The laser device according to claim 6, wherein: The buffer tank contains a discharge reactor that dissociates the XeF2 gas.

14. The laser device according to claim 6, wherein: The laser device further comprises a gas regeneration device for refining and pressurizing the laser gas exhausted from the laser cavity. The buffer tank is arranged on a path of the gas regeneration device.

15. The laser device according to claim 14, wherein: The gas regeneration device includes a first path and a second path, the first path passes through the buffer tank, the second path branches from the first path upstream of the buffer tank in the first path, avoids the buffer tank and merges with the first path downstream of the buffer tank in the first path.

16. The laser device according to claim 1, wherein: The laser device also has: A fan is disposed in the laser cavity to circulate the laser gas in the laser cavity; a gas exhaust port, which is disposed in the laser cavity; as well as a gas flow path that uses the airflow generated by the fan to return the laser gas exhausted from the laser cavity through the gas exhaust port to the laser cavity through the gas supply port, The XeF2 crystal is arranged in the gas flow path.

17. The laser device according to claim 16, wherein: The laser device further includes a filter arranged in the gas flow path. The XeF2 crystal is arranged downstream of the filter in the gas flow path.

18. The laser device according to claim 16, wherein: The laser device also has: An exhaust device for exhausting the laser cavity; a gas supply device for supplying laser gas into the laser cavity; and processor, The processor controls the exhaust device to exhaust the laser cavity. After the pressure in the laser cavity reaches the vapor pressure of the XeF2 crystal, the processor controls the gas supply device to supply laser gas into the laser cavity. The processor controls the exhaust device to exhaust a portion of the laser gas from the laser cavity, thereby adjusting the amount of XeF2 gas in the laser cavity.

19. The laser device according to claim 16, wherein: The laser device also has: A temperature regulator, which regulates the temperature of the XeF2 crystal; a gas supply device for supplying laser gas into the laser cavity; and processor, The processor controls the gas supply device to supply laser gas into the laser cavity until the pressure in the laser cavity reaches a first set pressure. The processor controls the temperature regulator so that the vapor pressure of the XeF 2 crystal becomes a second set pressure higher than the first set pressure, thereby adjusting the amount of XeF 2 gas in the laser cavity.

20. A method for manufacturing an electronic device, comprising the following steps: The laser is generated by a laser device, outputting the laser to an exposure device, The laser is exposed on a photosensitive substrate in the exposure device to manufacture an electronic device, and the laser device has: a laser cavity containing a laser gas containing fluorine; a pair of discharge electrodes disposed in the laser cavity; a gas supply port disposed in the laser cavity; and The XeF2 crystal is arranged in the XeF2 vaporization space communicating with the gas supply port and is vaporized.

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