Laser apparatus and method for manufacturing electronic device

Abstract

To provide a gas laser device having a narrow spectral linewidth.SOLUTION: A laser apparatus includes a laser chamber 10 containing a laser gas containing fluorine, a pair of discharge electrodes arranged within the laser chamber 10, a gas supply port 10d arranged in the laser chamber 10, and XeF2 crystals arranged in a XeF2 vaporization space communicating with the gas supply port and vaporized.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] In recent years, semiconductor exposure devices are required to improve their resolution in accordance with the miniaturization and high integration of semiconductor integrated circuits. For this reason, the wavelength of light emitted from the exposure light source is being shortened. For example, as gas laser devices for exposure, KrF excimer laser devices that output laser light with a wavelength of about 248 nm and ArF excimer laser devices that output laser light with a wavelength of about 193 nm are used.

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

[0004] [Patent Document 1] Summary of U.S. Patent Application Publication No. 2019 / 0237928

[0005] A laser apparatus according to one aspect of the present disclosure includes a laser chamber containing a laser gas containing fluorine, a pair of discharge electrodes disposed within the laser chamber, a gas supply port disposed in the laser chamber, and XeF2 crystals disposed in a XeF2 vaporization space communicating with the gas supply port and vaporized.

[0006] A method for manufacturing an electronic device according to one aspect of the present disclosure includes generating laser light using a laser apparatus including a laser chamber containing a laser gas containing fluorine, a pair of discharge electrodes disposed in the laser chamber, a gas supply port disposed in the laser chamber, and XeF2 crystals disposed in a XeF2 vaporization space communicating with the gas supply port and vaporized, outputting the laser light to an exposure apparatus, and exposing the laser light onto a photosensitive substrate in the exposure apparatus to manufacture an electronic device. [Brief description of the drawings]

[0007] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings. [Figure 1] FIG. 1 shows the configuration of an exposure system in a comparative example. [Diagram 2] FIG. 2 shows the configuration of an exposure system in a comparative example. [Diagram 3] FIG. 3 shows a partial configuration of a laser device according to a comparative example as viewed in the Z direction. [Figure 4] FIG. 4 shows a mechanism for supplying xenon gas in the first embodiment. [Diagram 5] FIG. 5 shows the details of the XeF2 vessel. [Figure 6] FIG. 6 is a table showing the relationship between the temperature T and the vapor pressure VP of the XeF2 crystal. [Figure 7] FIG. 7 is a flowchart showing a procedure for supplying xenon gas in the first embodiment. [Figure 8] FIG. 8 is a flowchart showing details of the pre-processing in the first embodiment. [Figure 9]FIG. 9 is a flowchart showing the details of the process of generating XeF2 gas in the XeF2 container in the first embodiment. [Figure 10] FIG. 10 is a flowchart showing details of the process of exhausting gas from within the laser chamber in the first embodiment. [Figure 11] FIG. 11 is a flowchart showing details of a process for supplying gas into the laser chamber in the first embodiment. [Figure 12] FIG. 12 is a flow chart showing details of the process of filling the XeF2 container with an inert gas in the first embodiment. [Figure 13] FIG. 13 is a flowchart showing details of post-processing in the first embodiment. [Figure 14] FIG. 14 shows an example of the relationship between the XeF2 concentration Cf and the actual xenon concentration Cx. [Figure 15] FIG. 15 shows an example of the relationship between the XeF2 concentration Cf and the pulse energy variation. [Figure 16] FIG. 16 shows the configuration of the buffer tank in the second embodiment. [Figure 17] FIG. 17 is a flowchart showing details of a process for generating XeF2 gas in a XeF2 container in the second embodiment. [Figure 18] FIG. 18 shows a mechanism for supplying xenon gas in the third embodiment. [Figure 19] FIG. 19 shows a partial configuration of the laser device according to the fourth embodiment as viewed in the -V direction. [Figure 20] FIG. 20 shows a partial configuration of the laser device according to the fourth embodiment as viewed in the Z direction. Embodiment

[0008] <Contents> 1. Comparative Example 1.1 Exposure system 1.2 Exposure apparatus 200 1.2.1 Configuration 1.2.2 Operation 1.3 Laser device 100 1.3.1 Configuration 1.3.2 Operation 1.4 Issues with the Comparative Example 2. Xenon gas supply using XeF2 crystals 2.1 Configuration 2.2 Operation 2.2.1 Main flow 2.2.2 Preprocessing 2.2.3 Process for generating XeF2 gas in the XeF2 container 47b 2.2.4 Process for exhausting gas from inside the laser chamber 10 2.2.5 Processing for supplying gas into the laser chamber 10 2.2.6 Process of filling the XeF2 container 47b with inert gas 2.2.7 Post-processing 2.3 Correction of XeF2 concentration Cf 2.4 Effect 3. Dissociation of XeF2 gas using a discharge reactor 3.1 Configuration 3.2 Operation 3.3 Effect 4. Gas regeneration device 49 including buffer tank 47a 4.1 Configuration 4.2 Operation of xenon addition in the gas regeneration device 49 4.3 Operation of xenon addition in fresh gas supply 4.4 Effect 5. XeF2 crystal 54 arranged in the flow path of the gas flow generated by the cross-flow fan 21 5.1 Configuration 5.2 Operation 5.3 Effect 6.Other

[0009] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure, and do not limit the contents of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and duplicated explanations will be omitted.

[0010] 1. Comparative Example 1.1 Exposure system 1 and 2 show the configuration of an exposure system in a comparative example. The comparative example of the present disclosure is a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0011] The exposure system includes a laser device 100 and an exposure device 200. The laser device 100 is shown in a simplified form in Fig. 1. The exposure device 200 is shown in a simplified form in Fig. 2. The laser device 100 is configured to output a laser beam toward the exposure device 200.

[0012] 1.2 Exposure apparatus 200 1.2.1 Configuration 1, exposure apparatus 200 includes illumination optical system 201 and projection optical system 202. Illumination optical system 201 illuminates a reticle pattern of a reticle (not shown) arranged on reticle stage RT with laser light incident from laser device 100. Projection optical system 202 reduces and projects the laser light transmitted through the reticle to form an image on a workpiece (not shown) arranged on workpiece table WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a resist film.

[0013] 1.2.2 Operation The exposure apparatus 200 synchronously moves the reticle stage RT and the workpiece table WT in parallel in opposite directions. This exposes the workpiece to laser light reflecting the reticle pattern. The reticle pattern is transferred to a semiconductor wafer by this exposure process. Electronic devices can then be manufactured through multiple processes.

[0014] 1.3 Laser device 100 1.3.1 Configuration As shown in Fig. 2, the laser device 100 includes a laser chamber 10, a pair of discharge electrodes 11a and 11b, a line narrowing 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 line narrowing module 14 and the output coupling mirror 15 constitute an optical resonator. The laser chamber 10 is disposed in the optical path of the optical resonator. The processor 130 is a processing device including a memory 131 in which a control program is stored, and a CPU (central processing unit) 132 that executes the control program. The processor 130 is specially configured or programmed to execute various processes included in the present disclosure.

[0015] 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. Fig. 2 shows the configuration of the laser device 100 as viewed in the -H direction. Fig. 3 shows the configuration of a part of the laser device 100 according to the comparative example as viewed in the Z direction.

[0016] The laser chamber 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 directions of the laser chamber 10. The cross-flow fan 21 corresponds to the fan in this disclosure.

[0017] A laser gas containing, for example, argon gas or krypton gas as a rare gas, fluorine gas as a halogen gas, and neon gas as a buffer gas is sealed in the laser chamber 10. Alternatively, a laser gas containing fluorine gas and a buffer gas may be sealed.

[0018] An opening is formed in a part of the laser chamber 10, and this opening is blocked by an electrical insulator 20. The electrical insulator 20 supports the discharge electrode 11a. A plurality of conductive parts 20a are embedded in the electrical insulator 20. Each of the conductive parts 20a is electrically connected to the discharge electrode 11a. A power supply device (not shown) is connected to the discharge electrode 11a via the conductive parts 20a.

[0019] A return plate 10c is disposed inside the laser chamber 10. The discharge electrode 11b is supported by the return plate 10c. The discharge electrode 11b is electrically connected to ground potential via the return plate 10c and a conductive member of the laser chamber 10. As shown in FIG. 3, the return plate 10c has gaps for passing the laser gas on the depth side and the front side of the paper surface of FIG. 2. The rotating shaft of the cross flow fan 21 is supported by a bearing fixed to the laser chamber 10 and is connected to a motor 22 disposed outside the laser chamber 10.

[0020] The preionization electrode 24 includes a dielectric pipe, an inner preionization electrode arranged inside the dielectric pipe, and one or more outer preionization electrodes arranged on the surface of the dielectric pipe. The preionization electrode 24 is arranged along the longitudinal direction of the discharge electrode 11b at a position upstream of the position of the discharge electrode 11b in the circulation direction of the laser gas.

[0021] The line narrowing module 14 includes a prism 14a and a grating 14b. The prism 14a and the grating 14b are arranged in this order on the optical path of the light emitted from the window 10a.

[0022] The gas supply device 42 includes a fluorine-containing gas cylinder 40, an inert gas cylinder 41, and a xenon gas cylinder 41c. In the present disclosure, a KrF excimer laser device is exemplified, in which the fluorine-containing gas cylinder 40 contains a fluorine-containing gas composed of neon gas, 1.25% krypton gas, and 1% fluorine gas, and the inert gas cylinder 41 contains an inert gas composed of neon gas and 1.25% krypton gas. The total chamber pressure and fluorine concentration can be adjusted by adjusting the total amount and partial pressure ratio of the gas supplied to the laser chamber 10 from the fluorine-containing gas cylinder 40 and the inert gas cylinder 41. For example, when the target pressure P(F2) after the injection of the fluorine-containing gas into the laser chamber 10 in a substantially vacuum state is set to 30 kPa, and the target total pressure Pt after the injection of the inert gas is set to 300 kPa, the fluorine concentration in the laser chamber 10 is 0.1%.

[0023] In order to stabilize the pulse energy E of the laser light, a small amount of xenon gas may be injected from the xenon gas cylinder 41c into the laser chamber 10. The optimum concentration of xenon gas is about 10 ppm.

[0024] Valves V6, V7, and V7c are provided on pipes connected to the fluorine-containing gas cylinder 40, the inert gas cylinder 41, and the xenon gas cylinder 41c, respectively. These pipes merge into one pipe provided with a valve V1 and are connected to a gas supply port 10d of the laser chamber 10. The valve V1 corresponds to the first valve in this disclosure, and the pipe provided with the valve V1 corresponds to the first pipe.

[0025] The exhaust device 43 includes a fluorine trap 43a and an exhaust pump 43b. A valve V10 is provided in a pipe connected to the exhaust device 43, and this pipe is connected to a gas exhaust port 10e of the laser chamber 10. The fluorine trap 43a removes at least fluorine from the laser gas exhausted from the laser chamber 10. The exhaust pump 43b is configured to exhaust the gas that has passed through the fluorine trap 43a to the outside of the laser apparatus 100, so that the inside of the laser chamber 10 can be made into an almost vacuum state. The almost vacuum is, for example, 0.1 kPa or less.

[0026] The pressure gauge P3 is configured to measure the pressure inside the laser chamber 10.

[0027] 1.3.2 Operation The processor 130 receives setting data for a target value Et of the pulse energy E and a light emission trigger signal from the exposure apparatus 200. The processor 130 transmits setting data for a charging voltage to a charger included in the power supply device based on the setting data for the target value Et of the pulse energy E. The processor 130 also transmits a trigger signal to the power supply device based on the light emission trigger signal. Upon receiving the trigger signal from the processor 130, the power supply device generates a pulsed high voltage from the electrical energy stored in the charger, and applies this high voltage between the discharge electrodes 11a and 11b.

[0028] When a high voltage is applied between the discharge electrodes 11a and 11b, a discharge occurs between the discharge electrodes 11a and 11b. This discharge is called a main discharge. The energy of the main discharge excites the laser medium in the laser chamber 10 and transitions to a high energy level. When the excited laser medium subsequently transitions to a low energy level, it emits light with a wavelength according to the difference in energy levels.

[0029] Light generated within the laser chamber 10 is emitted to the outside of the laser chamber 10 through windows 10a and 10b. The light emitted from the window 10a of the laser chamber 10 has its beam width in the H direction expanded by the prism 14a and enters the grating 14b.

[0030] The light incident on the grating 14b is reflected by the grooves of the grating 14b and diffracted in a direction according to the wavelength of the light. The wavelength of the diffracted light incident on the prism 14a from the grating 14b is selected by matching the angle of incidence of the light incident on the grating 14b with the angle of diffraction of the diffracted light of the desired wavelength. The prism 14a reduces the beam width in the H direction of the diffracted light incident on the grating 14b and returns the light to the laser chamber 10 via the window 10a.

[0031] The output coupling mirror 15 transmits and outputs a portion of the light emitted from the window 10 b of the laser chamber 10 , and reflects the other portion back into the laser chamber 10 .

[0032] In this way, the light emitted from the laser chamber 10 travels back and forth between the line narrowing module 14 and the output coupling mirror 15, and is amplified every time it passes through the discharge space between the discharge electrodes 11a and 11b. This light is narrowed in line every time it is turned back by the line narrowing module 14. The light thus oscillated and narrowed in line is output from the output coupling mirror 15 as laser light.

[0033] When motor 22 rotates cross flow fan 21, laser gas flows as shown by arrow B in Fig. 3 and circulates inside laser chamber 10. Discharge products generated by discharge between discharge electrodes 11a and 11b are removed from the discharge space by the flow of laser gas before the next discharge, and the discharge space and its vicinity become in a state with few discharge products, so that the discharge can be stabilized. Heat exchanger 23 exhausts the thermal energy of the laser gas that has become hot by the discharge to the outside of laser chamber 10.

[0034] Just 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 occurs around the preionization electrode 24. The corona discharge generates light with a short wavelength. This light with a short wavelength ionizes the xenon between the discharge electrodes 11a and 11b. The ionization of xenon before the main discharge is called preionization. Preionization makes it possible to generate a main discharge with little bias in the longitudinal direction of the discharge electrodes 11a and 11b, enabling stable output of laser light.

[0035] As the discharge between the discharge electrodes 11a and 11b in the laser chamber 10 is repeated, the impurities contained in the laser gas increase or the fluorine concentration decreases, so the laser gas is replaced or replenished. For example, the procedure for replacing all the gas in the laser chamber 10 is as follows. (1) The gas inside the laser chamber 10 is exhausted by the exhaust device 43, and the inside of the laser chamber 10 is made into a substantially vacuum state. (2) The gas supply device 42 injects a fluorine-containing gas from the fluorine-containing gas cylinder 40 into the laser chamber 10 . (3) A small amount of xenon gas is injected into the laser chamber 10 from the xenon gas cylinder 41c by the gas supply device 42. (4) The gas supply device 42 injects the inert gas from the inert gas cylinder 41 into the laser chamber 10 .

[0036] 1.4 Issues with the Comparative Example Injecting a small amount of xenon gas has the effect of stabilizing the pulse energy E, but it has the following three problems, and solving them is costly, so the use of xenon gas may be abandoned. (1) In addition to the fluorine-containing gas cylinder 40 and the inert gas cylinder 41, it is necessary to add equipment and piping for installing the xenon gas cylinder 41c. (2) Generally, gas cylinders contain gas of 10 MPa or more, and special transportation methods and permission from the authorities are required to transport such gas cylinders from the place of manufacture. (3) If the total pressure inside the laser chamber 10 is 300 kPa, the partial pressure of 10 ppm xenon gas is 0.003 kPa. It is difficult to accurately measure such a small pressure and introduce it into the laser chamber 10.

[0037] 2. Xenon gas supply using XeF2 crystals 2.1 Configuration Fig. 4 shows a mechanism for supplying xenon gas in the first embodiment. To supply xenon gas to the laser chamber 10, a buffer tank 47a and a XeF2 container 47b are connected to a gas supply port 10d via piping. In Fig. 4, arrows are attached to each valve to indicate a typical flow direction of gas in the piping, but each valve does not have to be a check valve.

[0038] The buffer tank 47a is a sealable container that communicates with the laser chamber 10 via a pipe including a valve V1 and a pipe including a valve V15. The XeF2 container 47b is a sealable container that communicates with the buffer tank 47a via a pipe including a valve V2. The valve V2 corresponds to the second valve in this disclosure, and the pipe including the valve V2 corresponds to the second pipe.

[0039] 5 shows the details of the XeF2 container 47b. The XeF2 container 47b contains therein a XeF2 crystal 54. The XeF2 crystal 54 is a sublimable solid, and has a vapor pressure VP of about 0.5 kPa at 25°C.

[0040] A temperature sensor 51, a temperature regulator 52, and a pressure gauge P2 are disposed in the XeF2 container 47b. The temperature sensor 51 measures the temperature in the XeF2 container 47b, preferably 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 chiller, or both, 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 based on the measurement result by the temperature sensor 51 in accordance with a control signal received from the processor 130. This adjusts the vapor pressure VP of the XeF2 crystal 54. The pressure gauge P2 measures the gas pressure in the XeF2 container 47b, and outputs the measurement result to the processor 130.

[0041] 6 is a table showing the relationship between the temperature T and the vapor pressure VP of the XeF2 crystal 54. The minimum value of the temperature range that can be adjusted by the temperature regulator 52 is T1, and the maximum value is Tn, and data on the vapor pressure VP of the XeF2 crystal 54 at each temperature T is stored in advance in the memory 131 (see FIG. 2). The processor 130 can refer to this data to calculate the target value of the temperature T for obtaining the desired vapor pressure VP.

[0042] 4 again, the buffer tank 47a and the XeF2 container 47b constitute the XeF2 vaporization space 47. The XeF2 vaporization space 47 communicates with the laser chamber 10 via a pipe including a valve V1 and a pipe including a valve V15.

[0043] 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 corresponds to the third valve in this disclosure. The exhaust device 43 can exhaust the XeF2 vaporization space 47 to a nearly vacuum state. By closing the valves V3 and V15 after the XeF2 vaporization space 47 is in a nearly vacuum state and waiting for a while, the inside of the XeF2 vaporization space 47 is filled with XeF2 gas at a pressure corresponding to the vapor pressure VP of the XeF2 crystals 54.

[0044] The XeF2 vaporization space 47 communicates with the gas supply device 42 through a pipe including a valve V4. The valve V4 corresponds to the fourth valve in this disclosure. When the valves V4, V15, and V1 are opened, the laser chamber 10 and the gas supply device 42 communicate with each other through the XeF2 vaporization space 47. When a fluorine-containing gas is supplied to the laser chamber 10, the valve V6 is opened, and when an inert gas is supplied, the valves V7 and V9 are opened. This allows the XeF2 gas in the XeF2 vaporization space 47 to be introduced into the laser chamber 10 together with the gas supplied from the fluorine-containing gas cylinder 40 or the inert gas cylinder 41. The XeF2 gas introduced into the laser chamber 10 is easily dissociated by the discharge between the discharge electrodes 11a and 11b.

[0045] The piping including the valve V4 is connected to the buffer tank 47a in the XeF2 vaporization space 47. Furthermore, when the valve V2 is closed, the buffer tank 47a and the XeF2 container 47b are blocked from each other. Therefore, when the valve V2 is closed and the valves V4, V15, and V1 are opened, the XeF2 gas introduced into the laser chamber 10 can be limited to only the XeF2 gas in the buffer tank 47a.

[0046] A pipe including a valve V19 may be used to supply gas directly to the laser chamber 10 from the fluorine-containing gas cylinder 40 or the inert gas cylinder 41 without introducing XeF2 gas into the laser chamber 10. The pipe including the valve V19 may be connected to a pipe including the valve V1 instead of being directly connected to the laser chamber 10.

[0047] The XeF2 container 47b communicates with the gas supply device 42 via a pipe including a valve V5. The valve V5 corresponds to the fifth valve in this disclosure. During a period when XeF2 gas is not generated or supplied to the laser chamber 10, the XeF2 container 47b is filled with gas, thereby suppressing the vaporization of the XeF2 crystals 54. It is preferable that the XeF2 container 47b is filled with the inert gas in the inert gas cylinder 41 via a pipe including the valve V7 and a pipe including the valve V5. The valve V2 may be opened to fill not only the XeF2 container 47b but also the entire XeF2 vaporization space 47 with the inert gas. Furthermore, the XeF2 vaporization space 47 may be filled with the inert gas via the valve V18 instead of the valve V5.

[0048] 4 shows a case where one gas supply device 42, one exhaust device 43, and one XeF2 vaporization space 47 are connected to one laser chamber 10, but the present disclosure is not limited to this. One gas supply device 42, one exhaust device 43, and one XeF2 vaporization space 47 may be connected to multiple laser chambers 10.

[0049] In other respects, the configuration of the first embodiment is similar to that of the comparative example.

[0050] 2.2 Operation 2.2.1 Main flow FIG. 7 is a flowchart showing a procedure for supplying xenon gas in the first embodiment.

[0051] In S100, the processor 130 performs pre-processing for supplying laser gas together with XeF2 gas to the laser chamber 10. Details of S100 will be described later with reference to FIG.

[0052] In S200, the processor 130 controls various valves so that XeF2 gas is generated in the XeF2 container 47b. Details of S200 will be described later with reference to FIG.

[0053] In S300, the processor 130 controls various valves so as to exhaust the gas inside the laser chamber 10. Details of S300 will be described later with reference to FIG.

[0054] In S400, the processor 130 controls various valves so that the laser gas is supplied together with the XeF2 gas into the laser chamber 10. Details of S400 will be described later with reference to FIG.

[0055] In S500, the processor 130 controls various valves to fill the XeF2 container 47b with an inert gas. Details of S500 will be described later with reference to FIG.

[0056] In S600, the processor 130 performs post-processing after supplying the laser gas to the laser chamber 10. Details of S600 will be described later with reference to FIG.

[0057] After S600, the processor 130 ends the processing of this flowchart.

[0058] 2.2.2 Preprocessing Fig. 8 is a flowchart showing details of the pre-processing in the first embodiment. The processing shown in Fig. 8 corresponds to the subroutine of S100 in Fig. 7.

[0059] In S101, the processor 130 obtains the following data: Target pressure after injection of fluorine-containing gas P(F2) ·Target total pressure Pt Laser chamber volume Vc Target xenon concentration Ct Buffer tank volume Vb

[0060] 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 injection of the fluorine-containing gas is determined from the target fluorine concentration in the laser chamber 10 and the target total pressure Pt. The laser chamber volume Vc and the buffer tank volume Vb can be stored in the memory 131 in advance.

[0061] In S102, the processor 130 calculates a target vapor pressure VPt of the XeF2 crystal 54. When all of the XeF2 gas inside the buffer tank 47a is introduced into the laser chamber 10, the XeF2 concentration Cf in the laser chamber 10 is given by the following Equation 1. Cf=(VPt·Vb) / (Pt·Vc) ···Equation 1

[0062] From Equation 1, the target vapor pressure VPt can be set to the following value. VPt=Pt·Vc·Cf / Vb···Formula 2

[0063] Here, when all of the XeF2 gas introduced into the laser chamber 10 is dissociated into xenon gas and fluorine gas, the XeF2 concentration Cf should be made to coincide with the target xenon concentration Ct, and the target vapor pressure VPt is given by the following equation. VPt=Pt Vc Ct / Vb

[0064] A correction for the case where the XeF2 concentration Cf calculated by Equation 1 does not match the actual xenon concentration Cx will be described later with reference to FIG.

[0065] In S103, the processor 130 calculates a target value of the temperature T of the XeF2 crystal 54. The target value of the temperature T of the XeF2 crystal 54 can be calculated based on the target vapor pressure VPt and the data shown in FIG.

[0066] In S104, the processor 130 acquires a measurement value of the temperature T of the XeF2 crystal 54 from the temperature sensor 51 (see FIG. 5).

[0067] In S105, the processor 130 starts temperature control of the XeF2 crystal 54 by the temperature adjuster 52. The temperature control is performed via the temperature controller 50 and continues until it is stopped in S602 of FIG.

[0068] In S106, the processor 130 starts the operation of the exhaust pump 43b. At this point, the operation of exhausting the laser chamber 10 and the buffer tank 47a is not performed. The operation of exhausting these spaces is turned on and off by opening and closing the valves. The operation of the exhaust pump 43b continues until it is stopped in S601 of FIG. 13.

[0069] After S106, the processor 130 ends the processing of this flowchart, and returns to the processing shown in FIG.

[0070] 2.2.3 Process for generating XeF2 gas in the XeF2 container 47b 9 is a flow chart showing details of the process for generating XeF2 gas in the XeF2 container 47b in the first embodiment. The process shown in FIG. 9 corresponds to the subroutine of S200 in FIG.

[0071] In S201, the processor 130 opens the valves V3, V15, and V2, thereby evacuating the inside of the buffer tank 47a and the XeF2 container 47b.

[0072] In S202, the processor 130 waits for a certain period of time. The pressure inside the buffer tank 47a and the XeF2 container 47b when the processor 130 waits for the certain period of time corresponds to the first pressure in the present disclosure. The first pressure is preferably a substantially vacuum state, but is not limited thereto, and may be any pressure lower than the target vapor pressure VPt.

[0073] In S203, the processor 130 closes the valves V15 and V3. This blocks communication between the XeF2 vaporization space 47 and the exhaust device 43. Furthermore, generation of XeF2 gas starts 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 corresponds to the second pressure in this disclosure.

[0074] In S204, the processor 130 judges whether the gas pressure obtained from the pressure gauge P2 of the XeF2 container 47b has reached the target vapor pressure VPt. Although an equal sign is shown in Fig. 9, it is not required that the pressure is completely the same, but it is only required to judge whether the pressure is within a predetermined error range. The same applies to Figs. 11 and 17.

[0075] If the gas pressure in 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.

[0076] When the gas pressure in 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. This blocks communication between the buffer tank 47a and the XeF2 container 47b.

[0077] After S206, the processor 130 ends the processing of this flowchart, and returns to the processing shown in FIG.

[0078] 2.2.4 Process for exhausting gas from inside the laser chamber 10 10 is a flowchart showing details of the process for exhausting gas from the laser chamber 10 in the first embodiment. The process shown in FIG 10 corresponds to the subroutine of S300 in FIG 7.

[0079] In S301, the processor 130 opens the valve V10, which starts exhausting the inside of the laser chamber 10.

[0080] In S302, the processor 130 determines whether the pressure inside the laser chamber 10 obtained from the pressure gauge P3 has become equal to or lower than 0.1 kPa.

[0081] If the pressure inside the laser chamber 10 is not equal to or lower 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.

[0082] If the pressure in the laser chamber 10 becomes 0.1 kPa or less (S302: YES), the processor 130 advances the process to S304. In S304, the processor 130 closes the valve V10. This blocks communication between the laser chamber 10 and the exhaust device 43.

[0083] After S304, the processor 130 ends the processing of this flowchart, and returns to the processing shown in FIG.

[0084] 2.2.5 Processing for supplying gas into the laser chamber 10 11 is a flowchart showing details of the process for supplying gas into the laser chamber 10 in the first embodiment. The process shown in FIG 11 corresponds to the subroutine of S400 in FIG 7.

[0085] In S401, the processor 130 opens the valves V1, V15, V4, and V6, thereby supplying the fluorine-containing gas in the fluorine-containing gas cylinder 40 into the laser chamber 10 together with the XeF2 gas in the buffer tank 47a.

[0086] In S402, the processor 130 determines whether the pressure inside the laser chamber 10 acquired from the pressure gauge P3 has reached the target pressure P(F2) after the injection of the fluorine-containing gas.

[0087] If the pressure inside the laser chamber 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.

[0088] When the pressure in the laser chamber 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. This stops the supply of the fluorine-containing gas from the gas supply device 42 to the buffer tank 47a.

[0089] In S405, the processor 130 opens the valves V7 and V9. This causes the inert gas in the inert gas cylinder 41 to be supplied into the laser chamber 10 via the buffer tank 47a. If XeF2 gas remains in the buffer tank 47a, the inert gas is supplied into the laser chamber 10 together with the XeF2 gas.

[0090] In S406, the processor 130 determines whether the pressure inside the laser chamber 10 acquired from the pressure gauge P3 has reached the target total pressure Pt of the laser chamber 10.

[0091] If the pressure inside the laser chamber 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.

[0092] When the pressure in the laser chamber 10 reaches the target total pressure Pt (S406: YES), the processor 130 advances the process to S408. In S408, the processor 130 closes the valves V4, V9, and V7. This stops the supply of the inert gas from the gas supply device 42 to the buffer tank 47a.

[0093] In S409, the processor 130 closes the valves V15 and V1, thereby isolating communication between the laser chamber 10 and the buffer tank 47a.

[0094] After S409, the processor 130 ends the processing of this flowchart, and returns to the processing shown in FIG.

[0095] 2.2.6 Process of filling the XeF2 container 47b with inert gas 12 is a flow chart showing details of the process of filling the XeF2 container 47b with an inert gas in the first embodiment. The process shown in FIG. 12 corresponds to the subroutine of S500 in FIG.

[0096] S501 to S503 are similar to S201 to S203 in Fig. 9. As a result, the inside of the buffer tank 47a and the XeF2 container 47b are evacuated.

[0097] In S504, the processor 130 opens the valves V7 and V5, whereby the inert gas in the inert gas cylinder 41 is supplied into the XeF2 container 47b and the buffer tank 47a.

[0098] In S505, the processor 130 determines whether the gas pressure acquired from the pressure gauge P2 of the XeF2 container 47b has reached 100 kPa or more.

[0099] If the gas pressure in the XeF2 container 47b is not 100 kPa or more (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.

[0100] 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. This completes the filling of the XeF2 vaporization space 47 with the inert gas from the gas supply device 42.

[0101] After S507, the processor 130 ends the processing of this flowchart, and returns to the processing shown in FIG.

[0102] 2.2.7 Post-processing 13 is a flowchart showing details of the post-processing in the first embodiment. The processing shown in FIG 13 corresponds to the subroutine of S600 in FIG 7.

[0103] 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 a discharge between the discharge electrodes 11a and 11b. This dissociates the XeF2 gas into xenon gas and fluorine gas. The discharge between the discharge electrodes 11a and 11b may be a discharge performed to output laser light to the exposure device 200, or may be a discharge performed with a shutter (not shown) between the laser device 100 and the exposure device 200 closed.

[0104] After S603, the processor 130 ends the processing of this flowchart, and returns to the processing shown in FIG.

[0105] 2.3 Correction of XeF2 concentration Cf The above explanation is based on the assumption that the XeF2 concentration Cf calculated by Equation 1 matches the actual xenon concentration Cx, but there may be cases where they do not match. For example, there may be cases where a portion of the XeF2 gas introduced into the laser chamber 10 does not dissociate, or where the XeF2 gas dissociates but recombines.

[0106] FIG. 14 shows an example of the relationship between the XeF2 concentration Cf and the actual xenon concentration Cx. The XeF2 concentration Cf may be corrected based on such a relationship. For example, it is assumed that the XeF2 concentration Cf calculated by Equation 1 and the actual xenon concentration Cx can be approximated by the following equation using a proportional constant A. Cx = A Cf

[0107] In this case, from equation 2, the target steam pressure VPt is given by the following equation. VPt=Pt Vc (Ct / A) / Vb

[0108] Methods for measuring the xenon concentration Cx to obtain the relationship shown in Fig. 14 include analyzing a sample gas with a mass spectrometer, or dispersing the interelectrode discharge light with a spectroscope to analyze the emission intensity at a wavelength of 354 nm, which is correlated with the xenon concentration Cx. 354 nm corresponds to the wavelength of the emission line of XeF. Such measurements may be performed before the shipment of the laser device 100, and the relationship shown in Fig. 14 may be stored in the memory 131. Alternatively, a mass spectrometer or a spectroscope may be attached to the laser device 100 to measure the xenon concentration Cx at any time.

[0109] FIG. 15 shows an example of the relationship between the XeF2 concentration Cf and the pulse energy variation. The pulse energy variation can be obtained, for example, by dividing the standard deviation of the pulse energy E of the laser light by the average value. The smaller the pulse energy variation, the better the stability of the pulse energy E. The pulse energy E can be measured by placing an energy sensor (not shown) in the optical path of the laser light. The optimal value Cfo of the XeF2 concentration Cf may be determined based on the relationship shown in FIG. 15. In this case, from Equation 2, the target vapor pressure VPt is given by the following equation. VPt=Pt Vc Cfo / Vb

[0110] 2.4 Effect In the first embodiment, the laser device 100 includes a laser chamber 10 that contains a laser gas containing fluorine, a pair of discharge electrodes 11a and 11b arranged in the laser chamber 10, a gas supply port 10d arranged in the laser chamber 10, and XeF2 crystals 54 that are arranged in a XeF2 vaporization space 47 that communicates with the gas supply port 10d and vaporized.

[0111] According to this, XeF2 gas generated from the XeF2 crystal 54 is introduced into the laser chamber 10, and the XeF2 gas is dissociated into xenon gas and fluorine gas by discharge, so that the pulse energy E of the laser light can be stabilized without using a xenon gas cylinder 41c.

[0112] According to the first embodiment, the laser device 100 further comprises a temperature regulator 52 for adjusting the temperature T of the XeF2 crystal .

[0113] According to this, the supply amount of XeF2 gas can be adjusted by adjusting the temperature T of the XeF2 crystal 54, so that the xenon concentration Cx in the laser chamber 10 can be adjusted to an optimum range.

[0114] According to the first embodiment, the laser apparatus 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 chamber 10.

[0115] According to this, the temperature regulator 52 can be controlled in accordance with the operating conditions of the laser device 100 to adjust the xenon concentration Cx with high precision.

[0116] According to the first embodiment, the processor 130 determines a target vapor pressure VPt of the XeF2 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.

[0117] According to this, by determining the target vapor pressure VPt, the amount of XeF2 gas generated can be adjusted with high precision.

[0118] According to the first embodiment, the XeF2 vaporization space 47 communicates with the laser chamber 10 via a first pipe including a valve V1.

[0119] According to this, during the period in which the XeF2 crystals 54 are vaporized, the amount of XeF2 gas generated can be limited by blocking the connection between the XeF2 vaporization space 47 and the laser chamber 10 with the valve V1, thereby allowing the xenon concentration Cx in the laser chamber 10 to be brought closer to the optimal range.

[0120] According to the first embodiment, the XeF2 vaporization space 47 includes a buffer tank 47a that communicates with the laser chamber 10 via a first pipe including a valve V1, and an XeF2 container 47b that communicates with the buffer tank 47a via a second pipe including a valve V2 and contains XeF2 crystals 54.

[0121] According to this, by dividing the XeF2 vaporization space 47 into the XeF2 container 47b and the buffer tank 47a and supplying the XeF2 gas in the buffer tank 47a into the laser chamber 10, the supply amount of the XeF2 gas can be adjusted with high precision.

[0122] According to the first embodiment, the laser device 100 includes an exhaust device 43 that exhausts 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, controls the exhaust device 43 so that the pressure in the XeF2 vaporization space 47 becomes a 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 that is higher than the first pressure.

[0123] According to this, by exhausting the inside of the XeF2 vaporization space 47, the amount of XeF2 gas generated within the XeF2 vaporization space 47 can be adjusted with high precision.

[0124] According to the first embodiment, the XeF2 vaporization space 47 communicates with a fluorine-containing gas cylinder 40 or an inert gas cylinder 41 that contains a laser gas.

[0125] According to this, the XeF2 gas generated in the XeF2 vaporization space 47 can be supplied to the laser chamber 10 together with the laser gas supplied from a gas cylinder having a higher pressure than the laser chamber 10.

[0126] According to the first embodiment, a valve V4 is disposed in the pipe connecting the buffer tank 47a to the fluorine-containing gas cylinder 40 or the inert gas cylinder 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 to supply the gas in the buffer tank 47a to the laser chamber 10 together with the laser gas supplied from the fluorine-containing gas cylinder 40 or the inert gas cylinder 41.

[0127] According to this, by supplying the laser gas from the gas cylinder to the buffer tank 47a, the XeF2 gas in the buffer tank 47a is supplied to the laser chamber 10 without waste, so that the supply amount of XeF2 gas to the laser chamber 10 can be adjusted with high precision.

[0128] According to the first embodiment, a valve V5 is disposed in the pipe connecting the XeF2 container 47b and the fluorine-containing gas cylinder 40 or the inert gas cylinder 41.

[0129] According to this, during the period when the XeF2 crystals 54 are not being used, the XeF2 container 47b is filled with gas (S504 to S506), and evaporation of the XeF2 crystals 54 can be suppressed.

[0130] According to the first embodiment, the XeF2 container 47b is filled with an inert gas supplied via a valve V5.

[0131] According to this, by filling the XeF2 container 47b with inert gas (S504 to S506) during the period when the XeF2 crystals 54 are not being used, the gas reaction can be suppressed.

[0132] In other respects, the first embodiment is similar to the comparative example.

[0133] 3. Dissociation of XeF2 gas using a discharge reactor 3.1 Configuration 16 shows the configuration of the buffer tank 47a in the second embodiment. The buffer tank 47a includes an electrode 62 connected to a power source 60 via a feedthrough 63. The power source 60 is preferably an AC power source or a pulsed power source. A switch 61 is disposed between the feedthrough 63 and the power source 60. The power source 60 and the switch 61 are controlled by the processor 130. The conductive material constituting the buffer tank 47a is connected to a ground potential. The electrode 62 corresponds to the discharge reactor in this disclosure.

[0134] XeF2 gas flows into the buffer tank 47a through the valve V2. The gas in the buffer tank 47a is supplied to the laser chamber 10 through the valve V15. Therefore, a gas flow as shown by the arrow C in FIG. 16 may occur in the buffer tank 47a. The longitudinal direction of the electrode 62 may be approximately the same as the direction of the gas flow. In order to efficiently dissociate the XeF2 gas, a plurality of buffer tanks 47a may be disposed in one laser device 100, and each may be provided with a discharge reactor.

[0135] In other respects, the configuration of the second embodiment is similar to that of the first embodiment.

[0136] 3.2 Operation Fig. 17 is a flow chart showing details of the process of generating XeF2 gas in XeF2 container 47b in the second embodiment. The process shown in Fig. 17 corresponds to the subroutine S200 in Fig. 7. In the second embodiment, the XeF2 gas generated in XeF2 container 47b is dissociated by a discharge reactor in buffer tank 47a.

[0137] The processes of S201 to S206 are similar to those described with reference to FIG. 9, and the XeF2 container 47b and the buffer tank 47a are blocked from each other in a state in which the insides of the XeF2 container 47b and the buffer tank 47a are filled with XeF2 gas at the target vapor pressure VPt.

[0138] In S207, the processor 130 turns on the switch 61. This causes a discharge between the electrode 62 and the conductive material of the grounded buffer tank 47a, and starts dissociation of the XeF2 gas.

[0139] In S208, the processor 130 waits until a predetermined time Tw has elapsed. In S209, the processor 130 turns off the switch 61.

[0140] After S209, the processor 130 ends the processing of this flowchart, and returns to the processing shown in FIG.

[0141] 3.3 Effect According to the second embodiment, the buffer tank 47a includes an electrode 62 as a discharge reactor for dissociating the XeF2 gas.

[0142] According to this, since the XeF2 gas can be supplied to the laser chamber 10 in a state in which it is dissociated into xenon gas and fluorine gas, a stable pulse energy E can be obtained from the first discharge after the gas is supplied.

[0143] In other respects, the second embodiment is similar to the first embodiment.

[0144] 4. Gas regeneration device 49 including buffer tank 47a 4.1 Configuration 18 shows a mechanism for supplying xenon gas in the third embodiment. This mechanism includes a gas regenerator 49. A pipe including a valve V10 branches into a pipe including a valve V11 and a pipe including a valve V12. The laser gas that has passed through the valve V11 flows to the exhaust device 43, and the gas that has passed through the valve V12 flows to the gas regenerator 49.

[0145] The gas regeneration device 49 includes a fluorine trap 44, a purification column 45, a boost pump 46, and a regeneration gas tank 48. The fluorine trap 44 removes at least fluorine from the laser gas. The purification column 45 includes a filter that removes impurities. The laser gas that has passed through the purification column 45 is also referred to as regeneration gas. The boost pump 46 delivers the regeneration gas at a pressure higher than the interior of the laser chamber 10.

[0146] The regeneration gas discharged from the boost pump 46 and passed through the valve V13 passes through either a first path passing through the valve V14, the buffer tank 47a, and the valve V15 in this order, or a second path branching off from the first path upstream of the valve V14, bypassing the buffer tank 47a, and joining the first path downstream of the valve V15. A valve V16 is disposed on the second path.

[0147] The regenerated 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 regenerated gas tank 48. When exhausting the buffer tank 47a, a pipe including a valve V3a is used instead of the valve V3.

[0148] A pipe including a valve V7b is connected to the inert gas cylinder 41 instead of the valves V7 and V9. The inert gas stored in the inert gas cylinder 41 is supplied to the buffer tank 47a through the valve V4. A helium gas cylinder 41a is connected to the pipe including the valve V7 instead of the inert gas cylinder 41. The helium gas stored in the helium gas cylinder 41a is supplied to the XeF2 container 47b through the valve V5. In this way, the inert gas filled in the XeF2 container 47b is helium gas, and may be a gas different from the gas contained in the laser gas supplied into the laser chamber 10. The configuration in which the XeF2 container 47b is filled with helium gas can also be adopted in the first and second embodiments.

[0149] In other respects, the third embodiment is similar to the first embodiment. Alternatively, in the third embodiment, a buffer tank 47a including a discharge reactor may be provided as in the second embodiment.

[0150] 4.2 Operation of xenon addition in the gas regeneration device 49 When filling the laser chamber 10 with laser gas, resources can be saved by using regenerated gas regenerated in the gas regenerator 49 instead of using new gas supplied from the gas supply device 42. However, since the gas regenerator 49 includes a fluorine trap 44 and the regenerated gas contains almost no fluorine gas, simply supplying the regenerated gas as is to the laser chamber 10 reduces the fluorine concentration in the laser chamber 10. Therefore, when the regenerated gas is supplied to the laser chamber 10, a fluorine-containing gas is added.

[0151] Since the fluorine-containing gas does not contain xenon gas, the xenon concentration Cx in the laser chamber 10 decreases when the supply of the regeneration gas and the addition of the fluorine-containing gas are repeated. Therefore, the decrease in the xenon concentration Cx can be suppressed by adding xenon gas according to the amount of the fluorine-containing gas added. The method of adjusting the amount of the xenon gas added is the same as in the first embodiment.

[0152] 4.3 Operation of xenon addition in fresh gas supply The operation of adding xenon when new gas is supplied from the gas supply device 42 to the laser chamber 10 is similar to that described with reference to Figures 7 to 13 and 17. However, the following points are changed. (1) In place of opening and closing both valves V3 and V15 in steps S201 and S203 in FIGS. 9 and 17, or steps S501 and S503 in FIG. 12, in the third embodiment, valve V3a is opened and closed. (2) Instead of opening and closing the valve V10 in S301 and S304 in FIG. 10, in the third embodiment, both the valves V10 and V11 are opened and closed. (3) In S405 and S408 of FIG. 11, instead of opening and closing both valves V7 and V9, in the third embodiment, valve V7b is opened and closed.

[0153] 4.4 Effect According to the third embodiment, the inert gas filled in the XeF2 container 47b is a gas different from the gas contained in the laser gas supplied to the laser chamber .

[0154] Since the inert gas filled in the XeF2 container 47b is exhausted (S201 to S203), it does not need to be the same as the gas contained in the laser gas, and a cheaper gas can be used.

[0155] According to the third embodiment, the laser apparatus 100 further includes a gas regeneration device 49 that refines and pressurizes the laser gas discharged from the laser chamber 10, and the buffer tank 47a is disposed on the path of the gas regeneration device 49.

[0156] According to this, when the fluorine-containing gas is supplied to the laser chamber 10 together with the regenerated gas in which the fluorine gas concentration has been reduced in the gas regenerator 49, the reduction in the xenon concentration Cx can be compensated for.

[0157] According to the third embodiment, the gas regeneration device 49 includes a first path passing through a buffer tank 47a, and a second path branching off from the first path upstream of the buffer tank 47a in the first path, avoiding the buffer tank 47a, and merging with the first path downstream of the buffer tank 47a in the first path.

[0158] According to this, when there is no need to add XeF2 gas to the regeneration gas, the regeneration gas can be supplied to the laser chamber 10 without passing through the buffer tank 47a.

[0159] In other respects, the third embodiment is similar to the first or second embodiment.

[0160] 5. XeF2 crystal 54 arranged in the flow path of the gas flow generated by the cross-flow fan 21 5.1 Configuration Fig. 19 shows a partial configuration of the laser device 100 according to the fourth embodiment as viewed in the -V direction. Fig. 20 shows a partial configuration of the laser device 100 according to the fourth embodiment as viewed in the Z direction.

[0161] In the fourth embodiment, a filter case 70 is connected to the laser chamber 10. The filter case 70 houses a filter 71. The filter case 70 communicates with the inside of the laser chamber 10 via a gas exhaust port 10e provided in the wall of the laser chamber 10, approximately in the center in the longitudinal direction of the discharge electrode 11a, and an intra-wall gas path 10f provided in the wall of the laser chamber 10 at both ends in the longitudinal direction of the discharge electrode 11a. The intra-wall gas path 10f opens into the inside of the laser chamber 10 at a gas supply port 10d located near the window 10a or 10b.

[0162] Using the gas flow generated by the cross-flow fan 21, the laser gas flows through a gas flow path from the gas exhaust port 10e through the filter case 70 and the gas path 10f in the wall to the gas supply port 10d. XeF2 crystals 54 are disposed in this gas flow path. This gas flow path is an example of the XeF2 vaporization space in this disclosure. The XeF2 crystals 54 are desirably disposed downstream of the filter 71 in the gas flow path.

[0163] Alternatively, the XeF2 crystals 54 may be disposed anywhere in the laser chamber 10. In that case, the XeF2 vaporization space in this disclosure does not have to be a container separate from the laser chamber 10, and the space in the laser chamber 10 also corresponds to the XeF2 vaporization space in this disclosure.

[0164] A temperature sensor 51 and a temperature regulator 52 are disposed on the wall surface of the gas flow path near the XeF2 crystal 54. The processor 130 (see FIG. 2) controls the temperature regulator 52 based on the temperature T of the XeF2 crystal 54 measured by the temperature sensor 51.

[0165] 2 are further connected to the laser chamber 10. However, the gas supply device 42 does not have to include the xenon gas cylinder 41c.

[0166] 5.2 Operation There are two methods for adjusting the xenon concentration Cx in the laser chamber 10 to the optimum range.

[0167] In the first method, first, the inside of the laser chamber 10 is evacuated to a nearly vacuum state by the exhaust device 43, and then all valves connected to the outside of the laser chamber 10 are closed. Then, XeF2 gas is generated from the XeF2 crystal 54. When the pressure inside the laser chamber 10 reaches the vapor pressure VP of the XeF2 crystal 54, the gas supply device 42 introduces laser gas at a target total pressure Pt into the laser chamber 10. When the XeF2 concentration VP / Pt in the laser chamber 10 at this time is X times the optimal value, the laser gas in the laser chamber 10 is further evacuated until the pressure reaches Pt / X. This adjusts the amount of XeF2 gas in the laser chamber 10. When the first method is used, the temperature sensor 51 and the temperature regulator 52 may not be required.

[0168] In the second method, first, the laser chamber 10 is evacuated to a nearly vacuum state by the exhaust device 43, and then the laser gas is supplied into the laser chamber 10 by the gas supply device 42 so that the pressure in the laser chamber 10 becomes a first set pressure Pi. Next, the temperature regulator 52 is controlled so that the vapor pressure VP of the XeF2 crystal 54 becomes a second set pressure Pj higher than the first set pressure Pi, and the XeF2 gas partial pressure after waiting for a sufficient time becomes Pj-Pi. The amount of XeF2 gas in the laser chamber 10 is adjusted by setting the first and second set pressures Pi and Pj so as to obtain the desired XeF2 gas partial pressure.

[0169] 5.3 Effect According to the fourth embodiment, the laser device 100 further includes a cross-flow fan 21, a gas exhaust port 10e disposed in the laser chamber 10, and a gas flow path. The cross-flow fan 21 is disposed in the laser chamber 10, and circulates the laser gas in the laser chamber 10 within the laser chamber 10. The gas flow path utilizes the gas flow generated by the cross-flow fan 21 to return the laser gas discharged from the laser chamber 10 through the gas exhaust port 10e to the laser chamber 10 through the gas supply port 10d. The XeF2 crystal 54 is disposed in the gas flow path.

[0170] According to this, the equipment for supplying the XeF2 gas generated from the XeF2 crystals 54 to the laser chamber 10 can be simplified.

[0171] 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.

[0172] According to this, by arranging the XeF2 crystals 54 downstream of the filter 71, it is possible to prevent impurities and dust from adhering to the surfaces of the XeF2 crystals 54, which would make it difficult to generate XeF2 gas.

[0173] According to the fourth embodiment, the laser apparatus 100 includes an exhaust device 43 that exhausts the inside of the laser chamber 10, a gas supply device 42 that supplies laser gas into the laser chamber 10, and a processor 130. The processor 130 controls the exhaust device 43 to exhaust the inside of the laser chamber 10, controls the gas supply device 42 to supply laser gas into the laser chamber 10 when the pressure in the laser chamber 10 reaches the vapor pressure VP of the XeF2 crystal 54, and further controls the exhaust device 43 to exhaust a part of the laser gas from the laser chamber 10, thereby adjusting the amount of XeF2 gas in the laser chamber 10.

[0174] According to this, even if a large amount of XeF2 gas is generated, the amount of XeF2 gas in the laser chamber 10 can be adjusted by exhausting a portion of the laser gas.

[0175] According to the fourth embodiment, the laser device 100 includes a temperature regulator 52 for adjusting the temperature T of the XeF2 crystal 54, a gas supply device 42 for supplying laser gas into the laser chamber 10, and a processor 130. The processor 130 controls the gas supply device 42 so that the laser gas is supplied into the laser chamber 10 until the pressure in the laser chamber 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 XeF2 gas in the laser chamber 10.

[0176] According to this, since the amount of generated XeF2 gas corresponds to the difference between the first and second set pressures Pi and Pj, the amount of generated XeF2 gas can be adjusted.

[0177] In other respects, the fourth embodiment is similar to the first embodiment.

[0178] 6.Other The above description is intended to be illustrative rather than restrictive. Thus, it will be apparent to one skilled in the art that modifications may be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments may be used in combination.

[0179] Terms used throughout the present specification and claims should be interpreted as "open ended" terms unless otherwise specified. For example, terms such as "include," "have," "comprise," and "include" should be interpreted as "not excluding the presence of elements other than those listed." In addition, the modifier "a" should be interpreted as "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be interpreted as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." Furthermore, it should be interpreted to include combinations of these with elements other than "A," "B," and "C."

Claims

1. a laser chamber containing a laser gas including fluorine; A pair of discharge electrodes disposed in the laser chamber; a gas supply port disposed in the laser chamber; XeF ２ XeF placed in the vaporization space and vaporized ２ Crystals and A laser device comprising:

2. 2. The laser device according to claim 1, The XeF ２ Temperature controller for controlling the crystal temperature The laser device further comprises:

3. 3. The laser device according to claim 2, a processor for controlling the temperature regulator based on a target total pressure and a target xenon concentration of the laser gas in the laser chamber; The laser device further comprises:

4. 4. The laser device according to claim 3, The processor determines the XeF based on the target total pressure and the target xenon concentration. ２ determining a target vapor pressure for the crystal, and controlling the temperature regulator based on the target vapor pressure; Laser device.

5. 3. The laser device according to claim 2, The XeF ２ the vaporization space communicates with the laser chamber via a first pipe including a first valve; Laser device.

6. 6. The laser device according to claim 5, The XeF ２ The evaporation space is a buffer tank communicating with the laser chamber via the first piping; The XeF ２ XeF containing crystals ２ A container; A laser device comprising:

7. 7. The laser device according to claim 6, The XeF ２ An exhaust device that exhausts the vaporization space; The XeF ２ a third valve between the vaporization space and the exhaust device; A processor; Further equipped with The processor, Open the third valve and ２ controlling the exhaust device so that a pressure in a vaporization space becomes a first pressure; The third valve is closed, and the XeF ２ controlling the temperature regulator so that the vapor pressure of the crystal is a second pressure higher than the first pressure; Laser device.

8. 8. The laser device according to claim 7, The XeF ２ The vaporization space communicates with a gas cylinder that contains laser gas. Laser device.

9. 9. The laser device according to claim 8, a fourth valve is disposed in a pipe connecting the buffer tank and the gas cylinder; The processor, The XeF ２ After the pressure in the vaporization space reaches the second pressure, the second valve is closed; by opening the fourth valve and the first valve, the gas in the buffer tank is supplied to the laser chamber together with the laser gas supplied from the gas cylinder; Laser device.

10. 9. The laser device according to claim 8, The XeF ２ A fifth valve is disposed in the pipe connecting the container and the gas cylinder. Laser device.

11. 11. The laser device according to claim 10, The XeF ２ The container is filled with an inert gas supplied through the fifth valve. Laser device.

12. 12. The laser device according to claim 11, The XeF ２ The inert gas filled in the container is a gas different from the gas contained in the laser gas supplied to the laser chamber. Laser device.

13. 7. The laser device according to claim 6, The buffer tank contains XeF ２ a discharge reactor for dissociating the gas; Laser device.

14. 7. The laser device according to claim 6, A gas regeneration device for refining and pressurizing the laser gas discharged from the laser chamber. Further equipped with The buffer tank is disposed in the path of the gas regenerator. Laser device.

15. 15. The laser device of claim 14, The gas regeneration device includes a first path passing through the buffer tank, and a second path branching off from the first path upstream of the buffer tank in the first path, avoiding the buffer tank, and merging with the first path downstream of the buffer tank in the first path. Laser device.

16. 2. The laser device according to claim 1, a fan disposed in the laser chamber for circulating a laser gas in the laser chamber; a gas exhaust port disposed in the laser chamber; a gas flow passage that utilizes a gas flow generated by the fan to return a laser gas discharged from the laser chamber through the gas exhaust port to the laser chamber through the gas supply port; Further equipped with The XeF ２ The crystal is disposed in the gas flow path. Laser device.

17. 17. The laser device of claim 16, A filter disposed in the gas flow path Further equipped with The XeF ２ The crystal is disposed downstream of the filter in the gas flow path. Laser device.

18. 17. The laser device of claim 16, an exhaust device that exhausts the inside of the laser chamber; a gas supply device for supplying a laser gas into the laser chamber; A processor; Further equipped with The processor, Controlling the exhaust device to exhaust the inside of the laser chamber; The pressure in the laser chamber is ２ When the vapor pressure of the crystal is reached, controlling the gas supply device to supply laser gas into the laser chamber; The exhaust device is controlled to exhaust a portion of the laser gas from the laser chamber, thereby ２ Regulating the amount of gas Laser device.

19. 17. The laser device of claim 16, The XeF ２ A temperature controller for controlling the temperature of the crystal; a gas supply device for supplying a laser gas into the laser chamber; A processor; Further equipped with The processor, controlling the gas supply device to supply laser gas into the laser chamber until the pressure in the laser chamber reaches a first set pressure; The XeF ２ The temperature regulator is controlled so that the vapor pressure of the XeF crystal is set to a second set pressure higher than the first set pressure, thereby ２ Regulating the amount of gas Laser device.

20. 1. A method for manufacturing an electronic device, comprising: a laser chamber containing a laser gas including fluorine; A pair of discharge electrodes disposed in the laser chamber; a gas supply port disposed in the laser chamber; XeF ２ XeF placed in the vaporization space and vaporized ２ Crystals and A laser beam is generated by a laser device comprising: outputting the laser light to an exposure device; The laser light is exposed onto a photosensitive substrate in the exposure apparatus to manufacture an electronic device. A method for manufacturing an electronic device, comprising:

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