JP2019141752A - Laser gas recycle system and method for the same - Google Patents

Abstract

To provide a laser gas recycle system and a method for the same capable of obtaining a refined gas in which predetermined impurities are removed from an exhaust gas exhausted from an excimer laser oscillation device.SOLUTION: A laser gas recycle system 1 for obtaining a refined gas whose main component is a high purity neon gas by removing predetermined impurities from an exhaust gas exhausted from an excimer laser oscillation device or the oscillation chamber of an excimer laser comprises: a separation membrane device 110 membrane-separating a rare gas for excitation except neon from a gas to be treated; and an impurity removal device 120 removing the predetermined impurities from a treated gas permeated (or non-permeated) in the separation membrane device 110.SELECTED DRAWING: Figure 1

Description

  The present invention removes predetermined impurities from exhaust gas discharged from an oscillation chamber of an excimer laser (or discharged out of the system of the excimer laser oscillation device), for example, krypton, which is a rare gas necessary for the excimer laser oscillation device. The present invention relates to a laser gas recycling system and method for recovering a neon gas containing, xenon and argon containing neon gas, xenon containing neon gas and high purity neon gas and reusing them as a recycled gas.

  As a recycling system for exhaust gas discharged from a conventional excimer laser oscillation device, there is a technology for removing impurities from the exhaust gas using various separation techniques such as low-temperature separation and extracting high-purity neon gas with a neon gas of 99% or more. .

  In addition, there is a technique in which predetermined impurities other than rare gas components such as argon and neon are extracted and reused using a catalyst or an adsorbent (see Patent Document 1).

  In addition, there is a method of removing a fluorine compound in a step of reusing exhaust gas discharged out of the system from an excimer laser oscillation device (see Patent Document 2). At least one treating agent selected from the group consisting of a combination of zeolite and calcium oxide and a combination of zeolite and calcium hydroxide is disclosed as a treating agent for removing fluorine compounds.

  In addition, there is a method of recovering neon gas from an excimer laser oscillation apparatus using a xenon-chlorine gas (see Patent Document 3). Hydrogen chloride is removed with an adsorbent such as soda lime. The hydrogen component reacts with oxygen by a catalyst to produce water, and moisture and carbon dioxide gas are removed by an adsorbent.

  In addition, it can remove trace impurities contained in the exhaust gas of various processes using krypton and xenon, and is installed near the excimer laser oscillator to separate and recover only rare gases (krypton and xenon), and to reuse rare gases There is a recovery device (see Patent Document 4). Patent Document 4 discloses a reducing substance removing step capable of converting hydrogen and ammonia into a gas mixture containing water vapor and nitrogen oxide by an oxidation reaction in the presence of at least one of oxygen and nitrogen oxide; A denitration step capable of converting nitrogen oxides and oxygen contained in the gas mixture after the removal step into nitrogen and water vapor by denitration catalytic reaction in the presence of ammonia, and ammonia and water vapor in the gas mixture after the denitration step The drying process which can remove is disclosed. Also disclosed is a method in which a hydrogen oxidation step is provided between the denitration step and the drying step so that hydrogen in the gas mixture can be converted into water vapor by a hydrogen oxidation reaction in the presence of oxygen.

  Further, there is a configuration in which halogen is removed from laser gas (exhaust gas) discharged from the excimer laser oscillation apparatus to the outside, a laser gas component is replenished after a predetermined refining process, and the gas is sent again to the excimer laser oscillation apparatus and reused ( (See Patent Document 5). In Patent Document 5, halogen gas is removed by an adsorbent (adsorbent in which a metal mainly composed of copper or zinc is supported on activated carbon), and nitrogen gas is separated by a low temperature adsorption method or a low temperature liquefaction rectification method. Is disclosed.

  There is also a method of recovering only high-purity neon gas from the exhaust gas of the main component neon gas containing a large amount of impurities discharged out of the system from the KrF excimer laser oscillator (see Patent Document 6). In Patent Document 6, fluorine is removed from an impure neon gas with an adsorbent (for example, soda lime), oxygen is then removed using a catalyst, carbon dioxide and moisture are then removed by an adsorption method, and then a low temperature adsorption method. And then removing impure neon gas and removing nitrogen and carbon monoxide by a low temperature adsorption method.

Japanese Patent No. 6175471 JP 2010-92920 A JP 2008-168169 A JP 2004-161503 A JP 11-54851 A JP 2001-232134 A

  However, in the above-described low-temperature separation method, a cryogenic technique such as −100 ° C. or less is used to extract neon gas in the exhaust gas discharged from the excimer laser oscillation apparatus as high-purity neon (to separate argon and krypton). Was necessary. In addition, when a cryogenic technique is not used, a separation method using a high pressure with a booster or the like and an adsorption technique has been proposed. However, the cryogenic technology, and the high-pressure and adsorption technology of exhaust gas require a great deal of energy, and the system is enlarged, which is not suitable for the need for a small space, and it has been difficult to implement easily.

  In addition, the component removal technologies other than neon disclosed in Patent Documents 1 to 6 mainly use a catalyst and an adsorbent. However, there is a demand for a removal technology with higher performance, better maintainability, and longer life. It was done.

  An object of the present invention is to provide a purified gas obtained by removing predetermined impurities from exhaust gas (or used laser gas) discharged from an excimer laser oscillator or an excimer laser oscillation chamber (inside or outside the excimer laser oscillator system). To provide a laser gas recycling system and method capable of obtaining a reusable laser gas).

In the laser gas recycling system of the present invention, the entire configuration or a part of the configuration may be disposed in the casing of the excimer laser oscillation device, or may be disposed separately from the excimer laser oscillation device.
When the laser gas recycling system of the present invention is arranged separately from the excimer laser oscillator, the laser gas recycling system performs a recycling process on the exhaust gas discharged from one excimer laser oscillator or one or more excimer laser oscillators. May be.

The laser gas recycling system of the present invention is a laser gas recycling system for removing a predetermined impurity from an exhaust gas discharged from an excimer laser oscillation device or an excimer laser oscillation chamber to obtain a purified gas (recycle gas) mainly composed of high-purity neon gas. A system,
A Ne separation membrane device for membrane separation of a rare gas for excitation (krypton, argon, xenon) other than neon from a gas to be treated (exhaust gas or first purified gas);
A first impurity removing device that removes predetermined impurities from the treated gas (high-concentration neon-containing gas) permeated (or non-permeated) by the Ne separation membrane device.
Here, when the treated gas is a high-concentration neon-containing gas, “high-concentration neon” means that the concentration is higher than the neon concentration in the gas to be treated before being introduced into the Ne separation membrane device. .
The exhaust gas is, for example, a gas containing a krypton-containing neon gas, an argon-containing neon gas, an argon / xenon-containing neon gas, or a xenon-containing neon gas laser gas and a predetermined impurity.
The first purified gas is, for example, a gas that has been processed to remove predetermined impurities from the exhaust gas upstream of the membrane separation device.
The laser gas includes a rare gas for excitation, a halogen, and a buffer gas.
According to the present invention, an excitation rare gas component other than neon, for example, xenon, krypton, and argon is removed by a Ne separation membrane device, and nitrogen, moisture, oxygen, and the like are removed by a first impurity removal device, Purity neon gas can be obtained. The concentration of the high purity neon gas in the obtained purified gas has a lower limit of 99% or more, 99.3% or more, preferably 99.5% or more, more preferably 99.8% or more, and particularly preferably 99.9%. The upper limit is 100%.
The above invention includes a recycle gas generation unit that mixes a predetermined additive gas with a purified gas (high purity neon gas) that has passed through the first impurity removal device so as to generate a necessary laser gas according to an excimer laser oscillation device. You may prepare.
Examples of the additive gas include halogen and rare gas-containing neon gas, rare gas-containing neon gas, halogen, rare gas, and rare gas. The rare gas here is any one of xenon, krypton, and argon, or a mixed gas of xenon and argon.
As a result, the obtained high-purity neon gas (first recycled gas) is mixed with an additive gas (for example, a rare gas for excitation) to generate the necessary laser gas (second recycled gas) according to the excimer laser oscillation device. It becomes possible to do.

Another laser gas recycling system of the present invention is a laser gas for removing a predetermined impurity from an exhaust gas discharged from an excimer laser device or an oscillation chamber of an excimer laser to obtain a purified gas (recycle gas) containing high-purity neon gas as a main component. A recycling system,
An Ar / Ne separation membrane device for removing a rare gas for excitation (xenon) other than argon and neon from a gas to be treated (exhaust gas or first purified gas);
A second impurity removing device that removes predetermined impurities from the processed gas (high-concentration argon / neon-containing gas) that has permeated (or not permeated) by the Ar / Ne separation membrane device.
Here, when the treated gas is a high-concentration argon / neon-containing gas, the “high-concentration argon / neon” means the concentration of argon / neon gas in the gas to be treated before being introduced into the Ar / Ne separation membrane device. Means high concentration.
The exhaust gas is, for example, a gas containing an argon / xenon-containing neon laser gas and predetermined impurities.
The first purified gas is, for example, a gas that has been processed to remove predetermined impurities from the exhaust gas upstream of the membrane separation device.
The laser gas includes a rare gas for excitation, a halogen, and a buffer gas.
According to the present invention, an excitation rare gas component other than argon and neon, for example, xenon is removed by an Ar / Ne separation membrane device, and nitrogen, moisture, oxygen, and the like are removed by a second impurity removal device. Containing high-purity neon gas can be obtained. The concentration of the argon-containing high-purity neon gas in the obtained purified gas has a lower limit of 99% or more, 99.3% or more, preferably 99.5% or more, more preferably 99.8% or more, and particularly preferably 99.%. It is 9% or more, and the upper limit is 100%.
In the above invention, a recycle gas generation in which a predetermined additive gas is mixed with a purified gas (argon-containing high-purity neon gas) that has passed through the second impurity removal device so as to generate a necessary laser gas according to an excimer laser oscillation device. May be provided.
Examples of the additive gas include halogen and rare gas-containing neon gas, rare gas-containing neon gas, halogen, rare gas, and rare gas. The rare gas here is, for example, argon and / or xenon.
In this way, the argon-containing high-purity neon gas (first recycle gas) is mixed with an additive gas (excitation rare gas), etc., and the necessary laser gas (second recycle gas) corresponding to the excimer laser oscillation device is mixed. Can be generated.

The Ne separation membrane device and / or the Ar / Ne separation membrane device may be composed of one or more separation membranes. In a plurality of cases, different types of separation membranes or the same type of separation membranes may be used.
When the Ne separation membrane device and / or the Ar / Ne separation membrane device is constituted by a plurality, the parallel arrangement, the series arrangement, the circulation arrangement, and the parallel arrangement are arranged in multiple stages (series arrangement, circulation arrangement). May be.
When a plurality of separation membranes are configured in multiple stages, a configuration may be employed in which a permeate gas is supplied to one subsequent separation membrane.
When a plurality of separation membranes are configured in multiple stages, a configuration may be adopted in which the non-permeating gas is re-supplied to the previous separation membrane.
When a plurality of separation membranes are configured in multiple stages, a configuration may be adopted in which the permeate gas emitted from the final-stage separation membrane is re-supplied to one of the preceding separation membranes (also referred to as a circulation type).

When a plurality of separation membranes are configured in multiple stages, a buffer tank and a booster (booster or compressor) may be arranged in the gas supply line of the separation membrane (upstream of the separation membrane).
When a plurality of separation membranes are configured in multiple stages, the permeate gas line of the separation membrane (downstream from the permeate gas outlet of the separation membrane), the pressure adjustment unit (may be a back pressure valve), the booster (booster or compressor) A flow rate adjusting unit (MFM or MFC) may be arranged.
When the Ne separation membrane device and / or the Ar / Ne separation membrane device are arranged in multiple stages (when a plurality of separation membranes are configured in multiple stages), the gas supply side line of the separation membrane is changed to the permeate gas line. In each line, a buffer tank, a booster (booster or compressor), a separation membrane, a pressure regulator (may be a back pressure valve), a booster (booster or compressor), and a flow regulator (MFM or MFC) are provided as unit units. The unit may be connected in multiple stages in series. In this unit, the flow rate adjusting unit and the buffer tank may or may not be provided.
When the Ne separation membrane device and / or the Ar / Ne separation membrane device are arranged in multiple stages (when a plurality of separation membranes are arranged in multiple stages), the separation membrane is connected to a non-permeating gas line (of the separation membrane). Downstream of the non-permeate gas outlet), a pressure adjusting unit (may be a back pressure valve) and / or a flow rate adjusting unit (MFM or MFC) may be provided, or both may be omitted. In the present invention, the pressure adjusting unit is not limited to the back pressure valve, the flow rate adjusting unit is not limited to the mass flow meter or the mass flow controller, and so on.

Examples of the separation membrane include organic membranes and inorganic membranes. For example, the organic film may be made of polyethylene or silicon. As the inorganic film, for example, ceramic or monocular sheep may be used.
The present invention includes a recovery line for recovering non-permeate gas flowing through a non-permeate gas line separated by a Ne separation membrane device and / or an Ar / Ne separation membrane device and / or a discharge line for discharging the system outside. Also good. The non-permeating gas may be reused as an additive gas after removing impurities as necessary. The non-permeating gas is, for example, a high-concentration rare gas-containing gas. In the present invention, “high concentration” means higher than the rare gas concentration in the exhaust gas before being supplied to the separation membrane device (separation membrane).

In the present invention, the separation membrane may be configured to selectively separate the rare gas (Kr, Xe, Ar), and the rare gas (Kr, Xe, Ar) may be determined by the difference in membrane permeation rate (pressure difference before and after the membrane). The structure which isolate | separates may be sufficient.
In the present invention, in the separation of the rare gas by the separation membrane, other components in the exhaust gas (or the first purified gas) may be separated together.

  In order to separate a predetermined rare gas selectively or more than other components from the gas to be treated (exhaust gas or first purified gas) introduced into the separation membrane, in the present invention, the rare gas ( Kr, Xe, Ar) may be separated.

For example, a rare gas (krypton, argon, or xenon) is separated from a gas to be treated (krypton-containing neon gas, argon-containing neon gas, or xenon-containing neon gas) as a non-permeate gas, and sent to a subsequent separation membrane as a permeate gas and a supply gas. . In this case, the flow rate of the gas to be processed that passes through the separation membrane can be controlled by the upstream pressurization unit disposed upstream of the separation membrane and / or the pressure adjustment unit and / or the downstream pressurization unit disposed downstream. . The pressure of the gas (supply gas) upstream of the separation membrane is set to the upstream pressure by the upstream pressurization unit, and the pressure of the permeated gas downstream of the separation membrane is set to a pressure lower than the upstream pressure by the pressure adjustment unit and / or the downstream pressurization unit. A downstream pressure is set, and a pressure difference (upstream pressure-downstream pressure) is provided. When this pressure difference is larger than the rare gas separation set value (krypton separation set value, argon separation set value, or xenon separation set value), the rare gas (krypton, argon, or xenon) is supplied from the supply gas (treated gas). To be separated. When the rare gas (krypton, argon, or xenon) is not separated by the first separation membrane, the rare gas (krypton, argon, or xenon) may be gradually separated by the separation membrane configured in multiple stages. Similarly to that of the preceding stage, the separation membrane at the rear stage is configured so that the flow rate of the gas to be processed passing through the separation membrane is changed to the upstream pressurizing unit disposed upstream of the separation membrane and / or the pressure adjusting unit disposed downstream. The noble gas (krypton, argon, or xenon) is separated by the pressure difference.
Even in the case of circulation through a single separation membrane, it can be controlled by an upstream pressurization unit arranged upstream of the separation membrane and / or a pressure adjustment unit and / or a downstream pressurization unit arranged downstream. The same applies hereinafter.

  Further, argon / xenon is separated from the gas to be treated (argon / xenon-containing neon gas) as a non-permeate gas, and the permeate gas is supplied as a supply gas to a subsequent separation membrane. In this case, the flow rate of the gas to be processed that passes through the separation membrane can be controlled by the upstream pressurization unit disposed upstream of the separation membrane and / or the pressure adjustment unit and / or the downstream pressurization unit disposed downstream. . The pressure of the supply gas upstream of the separation membrane is set to the upstream pressure by the upstream pressurization unit, and the pressure of the permeate gas downstream of the separation membrane is set to the downstream pressure lower than the upstream pressure by the pressure adjustment unit and / or the downstream pressurization unit. A pressure difference (upstream pressure-downstream pressure) is provided. When this pressure difference is larger than the argon / xenon separation set value, the argon / xenon is separated from the supply gas (processed gas). In the case where argon / xenon is not separated by the first separation membrane, the argon / xenon may be gradually separated by a multi-stage separation membrane. Similarly to that of the preceding stage, the separation membrane at the rear stage is configured so that the flow rate of the gas to be processed passing through the separation membrane is changed to the upstream pressurizing unit disposed upstream of the separation membrane and / or the pressure adjusting unit disposed downstream. The xenon is separated by the pressure difference.

When the separation factor ratio of argon to neon gas and the separation factor ratio of xenon differ depending on the type of separation membrane, it is preferable to set a pressure difference based on components that are difficult to separate. This is because by making the pressure difference based on components that are difficult to separate, the other easily separated component is also separated simultaneously.
In addition, when separating xenon as a non-permeating gas without separating argon from the gas to be treated (argon / xenon-containing neon gas), a separation membrane that is difficult to separate argon is used, and xenon is separated without separating argon. As described above, the flow rate of the gas to be treated is preferably controlled by the upstream pressurization unit disposed upstream of the separation membrane and / or the pressure adjustment unit and / or the downstream pressurization unit disposed downstream.

  In the present invention, when the gas to be processed (permeate gas) that has passed through the final separation membrane is supplied to one of the front separation membranes and circulated, the gas to be processed that has passed through the final separation membrane is separated. A second purified gas line (L4) sent to the impurity removing device downstream from the membrane device, and a return line (R1) branched from the second purified gas line (L4) and connected to one of the supply lines of the front separation membrane R2) and a valve provided in the return line and / or the second purified gas line (L4). By opening and closing the valve, the gas to be treated can be controlled to be circulated and / or sent to a downstream impurity removing device.

Said 1st, 2nd impurity removal apparatus may have a 1st removal part (oxygen removal part) which removes oxygen, and / or a 2nd removal part which removes impurities other than oxygen. The second removal unit may be a getter. Impurities other than oxygen removed by the getter are, for example, nitrogen, carbon monoxide, carbon dioxide, water, CH ₄ and the like.
In the present invention, an upstream oxygen removing unit that removes oxygen may be provided upstream of the Ne separation membrane device and / or the Ar / Ne separation membrane device. When the oxygen removing unit is not provided as a component of the first and second impurity removing devices, it is preferable that the upstream oxygen removing unit is provided.
In the present invention, Ar / Ne or Ne separation membrane device, first / second impurity removal device (oxygen removal unit, getter) may be arranged in this order as the arrangement of components having an impurity removal function, upstream side The oxygen removal unit, the Ar / Ne or Ne separation membrane device, and the getter may be arranged in this order.

The present invention is arranged upstream and / or downstream from the Ne separation membrane device and / or the Ar / Ne separation membrane device, and is used to increase the pressure to a predetermined pressure and / or to send exhaust gas downstream (for example, a compressor). ) May be provided.
In the present invention, the Ne separation membrane device and / or the Ar · Ne separation membrane device may be provided with a booster (for example, a compressor) in the recovery line and / or the discharge line.
The present invention is also provided with a booster (for example, a compressor) that is disposed upstream and / or downstream of the first and second impurity removal devices and that boosts the pressure to a predetermined pressure and / or feeds exhaust gas downstream. May be.
In the present invention, a booster (for example, a compressor) may be disposed upstream or downstream of the upstream oxygen removal unit.
In the present invention, a booster (for example, a compressor) may be disposed upstream of the oxygen removing unit and / or the getter.

The present invention provides a buffer tank (or recovery container) for storing exhaust gas upstream of a Ne separation membrane device and / or an Ar / Ne separation membrane device, or upstream of a booster (for example, a compressor) arranged upstream thereof. One or more may be provided.
The present invention may include one or more buffer tanks (or recovery containers) for storing purified gas downstream from the first and second impurity removal devices.

  The present invention provides a pressure adjusting unit that adjusts the pressure of exhaust gas flowing downstream from a Ne separation membrane device and / or an Ar / Ne separation membrane device, or upstream from a boosting unit (for example, a compressor) arranged upstream thereof. It may be a back pressure valve) and / or a flow rate adjusting unit for adjusting the flow rate of the exhaust gas. In the present invention, the pressure adjusting unit is not limited to the back pressure valve, the flow rate adjusting unit is not limited to the mass flow meter or the mass flow controller, and so on.

The recycle gas generator is
A purified gas line (first recycle gas line) disposed downstream from the first and second impurity removal devices;
A pressure adjusting unit (which may be a back pressure valve) for adjusting the pressure of the purified gas and / or a flow rate adjusting unit for adjusting the flow rate of the purified gas, disposed in the purified gas line (first recycle gas line);
An additive gas line for supplying the additive gas;
A pressure adjusting unit (which may be a back pressure valve) for adjusting the pressure of the additive gas, and / or a flow rate adjusting unit for adjusting the flow rate of the additive gas, arranged in the additive gas line;
The refinement gas line (first recycle gas line) and the addition gas line join together (P).
For example, the additive gas may be stored in a gas cylinder, a cylinder, a buffer tank, or the like.
When the additive gas is an argon / xenon-containing neon gas, for example, the argon concentration is 100% to 7% and the xenon concentration is 3000 ppm to 20 ppm. When the argon concentration is 100%, the neon gas concentration is 0%.
When the additive gas is krypton-containing neon gas, for example, the krypton concentration is 100% to 2.5%. When the krypton concentration is 100%, the neon gas concentration is 0%.
When the additive gas is a xenon-containing neon gas, for example, the xenon concentration is 100% to 20 ppm. When the krypton concentration is 100%, the neon gas concentration is 0%.
The joining point may be one where the pipes of the refined gas line or the addition gas line join together, or the two join together via a buffer tank.

  In the present invention, a bypass line may be provided that bypasses downstream so as not to pass through the Ne separation membrane device and / or the Ar / Ne separation membrane device. A bypass line that bypasses downstream so as not to pass through the upstream oxygen removal unit may be provided. A bypass line that bypasses downstream so as not to pass through the first and second impurity removal units (oxygen removal unit and / or getter) may be provided.

The present invention may have a fluorine compound removing unit that removes a fluorine compound, which is a kind of impurity, upstream or downstream of the Ne separation membrane device and / or the Ar / Ne separation membrane device.
The present invention may have a decomposition apparatus that decomposes fluorocarbon (CF ₄ or the like), which is a kind of impurity, into a decomposition byproduct.
The present invention may have a decomposition by-product removing unit that removes the decomposition by-product generated by the decomposition apparatus from the exhaust gas by reacting with a predetermined reactant. The decomposition by-product when the fluorocarbon is decomposed is, for example, a fluorine compound.
The present invention does not have a fluorine compound removal unit, and may have a decomposition apparatus and a decomposition byproduct removal unit.
The present invention may have an impurity concentration measuring unit for measuring the impurity concentration in the exhaust gas upstream of the Ne separation membrane device and / or the Ar / Ne separation membrane device. The impurity concentration measuring unit may be set upstream or downstream of the fluorine compound removing unit.
The impurity concentration measuring unit may be installed upstream of the decomposition apparatus and used to determine whether or not impurities are removed by the decomposition apparatus. The impurity concentration measuring unit may be installed downstream from the decomposition apparatus and measure the concentration of impurities after being processed by the decomposition apparatus.
The impurity concentration measuring unit may measure the concentration of one or more of CF ₄ , N ₂ , and He as impurities in the exhaust gas.
The present invention may have a buffer tank (or a recovery container) for storing exhaust gas upstream and / or downstream from the decomposition apparatus.
The present invention may have a buffer tank (or a recovery container) for storing exhaust gas upstream and / or downstream from the decomposition byproduct removal unit.
The present invention may have a buffer tank (or a recovery container) for storing exhaust gas upstream and / or downstream from the impurity concentration measuring section.
The present invention may have a buffer tank (or a recovery container) for storing exhaust gas upstream and / or downstream from the fluorine compound removing section.

  In the above invention, “in-system” means a component (including an element protruding from the casing) connected to the casing and the excimer laser oscillation if the excimer laser oscillation device is a single casing. In the case where the apparatus is configured by a plurality of casings, the configuration includes an arrangement in which the casings are in contact with each other or a configuration in the vicinity thereof.

  In the present invention, unless otherwise specified, “upstream” and “downstream” mean an arrangement relationship in the flow direction of gas (exhaust gas, purified gas, recycle gas, raw material laser gas, etc.). The same applies hereinafter.

The excimer laser oscillation device is a kind of gas laser and oscillates light in the ultraviolet region. In the oscillation chamber, by applying a high voltage (high voltage pulse discharge) to the excitation gas with at least a pair of electrodes, an excimer in an excited state is generated, and stimulated emission is caused to obtain light (ultraviolet rays).
The light emitted from the oscillation chamber may be adjusted to a specific wavelength width by, for example, a band- narrowing module (configured with a prism and a grating). The light returned from the banding module to the oscillation chamber is amplified by passing between the pair of electrodes. In addition, the narrowband module and the output mirror are connected by an optical path line so as to pass through the oscillation chamber, and each time the light reciprocates between the narrowband module and the output mirror, it passes between the pair of electrodes. The light is amplified. The function of the resonator is realized by the narrow banding module and the output mirror. The light that has passed through the output mirror is output as an output laser beam, for example, to an exposure apparatus.
The laser gas filled in the oscillation chamber includes, for example, a buffer gas such as neon gas (for example, 90 to 95%), a rare gas (Kr, Ar, Xe) (for example, 5 to 9%), and a halogen gas (F ₂ ). (For example, 1 to 5%). For example, examples of the excitation gas include KrF, ArF, XeF, and Ar / XeF.

The excimer laser oscillation device is
One or more laser gas supply lines for supplying one or more laser gases to the oscillation chamber;
The oscillation chamber to which laser gas is supplied from the laser gas supply line;
An exhaust gas line for sending laser gas (exhaust gas) discharged from the oscillation chamber to a laser gas recycling system may be provided.
A control valve, a gas pressure adjustment unit or a gas pressure gauge, and / or a gas flow rate adjustment unit or a gas flow meter may be installed in the exhaust gas line and the laser gas supply line.
The excimer laser oscillation device may have a discharge pump.
The excimer laser oscillation device may include a laser gas pressure gauge that measures the pressure of the laser gas in the oscillation chamber.
The excimer laser oscillation device includes a control valve, a gas pressure adjusting unit or a gas pressure gauge, and / or a supply of laser gas to the oscillation chamber at a predetermined pressure and a predetermined amount, and discharge of a predetermined amount of laser gas from the oscillation chamber. A gas flow rate adjusting unit or a gas flow meter may be installed and controlled by a laser gas supply / discharge control unit.
The gas pressure in the oscillation chamber and the supply pressure (first pressure) of the laser gas are set according to the specifications of the excimer laser oscillation apparatus, but are usually higher than atmospheric pressure, for example, 300 KPa or more in gauge pressure. A range of ˜700 KPa, preferably a range of 400 KPa to 700 KPa, more preferably a range of 500 KPa to 700 KPa is exemplified.
The pressure of the exhaust gas discharged from the oscillation chamber is equal to or higher than atmospheric pressure and equal to or lower than the supply pressure (first pressure). For example, the gauge pressure ranges from 50 KPa to 200 KPa.
The pressure of the exhaust gas boosted to a predetermined pressure by a booster upstream or downstream of the Ne separation membrane device and / or the Ar / Ne separation membrane device is a value larger than the first pressure, for example, The difference is in the range of 50 KPa to 150 KPa in gauge pressure.

The present invention provides a decomposition removal treatment line for sending the exhaust gas to the fluorine compound removal unit and / or the decomposition apparatus and the decomposition byproduct removal unit based on the result measured by the impurity concentration measurement unit. You may have. The decomposition and removal treatment line may be connected to an exhaust gas line connected to the oscillation chamber, and may also serve as the exhaust gas line.
The present invention may have a discharge line for discharging the exhaust gas out of the system (in the atmosphere) based on the result measured by the impurity concentration measuring unit.
The present invention provides a bypass line for sending the exhaust gas to a subsequent process (separation membrane device) without sending the exhaust gas to the cracking device and the cracking byproduct removal unit based on the result measured by the impurity concentration measuring unit. You may have.
The present invention includes (1) only decomposition / removal processing line, (2) decomposition / removal processing line and discharge line, (3) decomposition / removal processing line and bypass line, (4) decomposition / removal processing line, discharge line, and bypass line. A line configuration including the above may be used. Depending on the line configuration from (2) to (4), the process selection unit described later may be configured to select the first process, the second process, and the third process.

The present invention includes a first process for discharging exhaust gas to the outside air, a second process for performing an impurity removal process, and a subsequent process (separation membrane device) based on the results measured by the impurity concentration detector. You may have the process selection part which selects either the 3rd process which sends waste gas.
When the first process is selected by the process selection unit, the exhaust line is discharged to the outside air at the discharge line,
When the second treatment is selected by the treatment selection unit, the exhaust gas is sent to the fluorine compound removal unit and / or the decomposition device and the decomposition byproduct removal unit provided in the decomposition removal treatment line. , Decomposing and removing impurities in the exhaust gas,
When the third process is selected by the process selection unit, the exhaust gas may be sent to a subsequent process (separation membrane apparatus) through the bypass line.
When the first treatment is selected, the exhaust gas is released to the discharge line, and when the second treatment is selected, the exhaust gas is sent to the decomposition / removal treatment line, and the third treatment is selected. A valve control unit that controls opening and closing of the valve may be provided so as to send the exhaust gas to the bypass line.

The decomposition device may be, for example, a silent discharge device or a short wavelength light oscillation device. Examples of the short wavelength light include excimer laser light and UV laser light. The cracking device may have a cracking chamber. The exhaust gas may be sent from the oscillation chamber to the decomposition chamber, and the excimer laser light may be irradiated in the decomposition chamber to decompose the impurities (CF ₄ ) in the exhaust gas. CF ₄ is decomposed into decomposition by-products (F ₂ , other fluorine compounds), and the decomposition by-products may be absorbed and removed by reacting with a predetermined reactant in the decomposition by-product removing unit. .

  In the present invention, the “predetermined reactant” is, for example, a metal reactant or a gas absorption reactant. Examples of the metal-based reactant include Ag-based and Cu-based reactants. Examples of the gas absorption type reactive agent include an acidic gas absorption reactive agent. For example, an oxygen-containing substance typified by soda lime is used as the reactive agent.

The fluorine compound is, for example, SiF ₄ or COF ₂ .
The fluorocarbon is, for example, CF ₄ .
The decomposition / removal processing line may include, for example, a pipe and an automatic opening / closing valve.
For example, the bypass line may include a pipe and an automatic opening / closing valve.
For example, the discharge line may include a pipe, a vent device for discharging outside air, an automatic opening / closing valve, and the like.
The impurity concentration measurement unit may be disposed in a pipe such as a decomposition / removal processing line, for example, may be disposed in a space where concentration measurement can be performed, or may be disposed in a buffer tank.
In the present invention, “purified gas” and “recycle gas” are, for example, high-purity neon gas or main component neon gas containing a rare gas (eg, Ar).
In the present invention, the impurities in the exhaust gas include, for example, any one or more of CF ₄ , N ₂ , He, oxygen, and moisture. Noble gases (eg, argon, krypton, xenon) and buffer gases such as neon are not impurities unless specifically stated as impurities.

In the present invention, when the impurity concentration measuring unit is provided, the concentration of impurities (for example, CF ₄ ) in the exhaust gas sent from the oscillation chamber can be measured, and various treatments can be performed on the exhaust gas according to the measurement result. .
In the present invention, for example, when the impurity concentration is a high concentration higher than a predetermined concentration range (for example, 10 ppm to 120 ppm), it is released to the outside air, and if the impurity concentration is a predetermined concentration range (for example, 10 ppm to 120 ppm), impurities are removed. If the impurity concentration is less than a predetermined concentration range (for example, 10 ppm to 120 ppm), the exhaust gas can be sent to the subsequent process (process of the separation membrane device) as it is.
The exhaust gas recycling process (partial impurity removal process, total impurity removal process depending on the embodiment) can be performed not only outside the excimer laser oscillation system but also inside the system. For example, impurities are removed from exhaust gas not only outside the ArF excimer laser oscillation apparatus and KrF excimer laser oscillation system, but high purity neon gas or argon-containing high purity neon gas is purified and recycled as a recycled gas. Can be used.
Further, in the present invention, a cryogenic treatment, a high pressure treatment of 1 MPaG or more is unnecessary.
Further, since the separation membrane can be made into a compact device configuration, it can be incorporated in the system (housing) of the excimer laser oscillation device.

In the above invention, when the impurity concentration detector measures the concentration of CF _{4 in} the exhaust gas,
When the concentration of CF ₄ is equal to or higher than the first threshold, the process selection unit selects the first process,
When the concentration of CF ₄ is greater than a second threshold value that is smaller than the first threshold value and less than the first threshold value, the process selection unit selects the second process,
When the concentration of CF ₄ is less than the second threshold value, the process selection unit may perform control to select the third process.
As described above, according to the line configuration of the disassembly / removal processing line, the discharge line, and the bypass line, a process corresponding to the line configuration is selected.
In the above invention, the “first threshold value” is, for example, an arbitrary value between 80 ppm and 110 ppm, preferably an arbitrary value between 90 ppm and 100 ppm, and more preferably 100 ppm.
In the above invention, the “second threshold value” is, for example, any numerical value between 5 ppm and 15 ppm, preferably any numerical value between 8 ppm and 12 ppm, and more preferably 10 ppm.
In the present invention, unless otherwise specified, mass or weight means volume concentration.

The exhaust gas is mainly composed of neon, and the rare gas (krypton, xenon, argon) is 1 to 10%, preferably 1 to 8%, based on the total amount. Examples of impurities in the exhaust gas include CF ₄ , N ₂ , and He. The CF ₄ concentration in the exhaust gas is assumed to be in the range of 1 ppm to 500 ppm.

When the CF ₄ concentration is equal to or higher than the first threshold (for example, 100 ppm), the process selection unit selects the first process. In the first treatment, exhaust gas is discharged out of the system through the discharge line.
When a certain amount (for example, 100 ppm) or more of CF ₄ is introduced into the cracking device, a part of CF ₄ contained in the exhaust gas is not decomposed and cannot be completely removed. ₄ Complete removal can be carried out by taking out the exhaust gas that may be insufficiently removed from the system in advance.
Further, in the case of CF _{4 having} a high concentration, the amount of decomposition by-products generated in the decomposition apparatus increases, and the frequency of replacement of a predetermined reactant (for example, a metal-based reactant and a gas-absorbing-type reactant) increases. Since problems such as corrosion of pipes and valves occur, CF ₄ having a concentration higher than the first threshold value is not introduced into the decomposition apparatus to reduce these problems. You may set the value of a 1st threshold value according to the capability of a decomposition | disassembly apparatus.
When the CF ₄ concentration is larger than a second threshold (for example, 10 ppm) smaller than the first threshold and less than the first threshold, the second process is selected. In the second treatment, exhaust gas is introduced into the decomposition apparatus from the decomposition / removal processing line. In the decomposition apparatus, CF ₄ becomes a decomposition by-product (F ₂ , other fluorine compound) by, for example, UV laser light, excimer laser light, or plasma decomposition, and the decomposition by-product is a predetermined reactant (for example, metal-based reaction). Removed by reaction with an agent, a gas absorption type reaction agent).
When the CF ₄ concentration is less than the second threshold, the third process is selected, and the third process bypasses the decomposition apparatus and introduces the exhaust gas into the subsequent membrane separation apparatus as it is.

When the impurity concentration measuring unit measures the concentration of CF ₄ , N ₂ and He in the exhaust gas,
(A) The He concentration is greater than or equal to a third threshold value,
(B) either CF ₄ or N ₂ is greater than or equal to the first threshold (eg, any value between 80 ppm and 110 ppm, preferably 90 ppm to 100 ppm), or
(C) He concentration is less than the third threshold value, and either CF ₄ or N ₂ is equal to or greater than the second threshold value (for example, any numerical value between 5 ppm and 15 ppm, preferably 8 ppm to 12 ppm). When the density is less than the threshold and the density relationship is N ₂ > (1/2) × CF ₄ , the process selection unit selects the first process.
(D) In the case where the He concentration is less than the third threshold, the concentration of N ₂ or CF ₄ is greater than or equal to the second threshold and less than the first threshold, and the magnitude relationship of the concentrations is N ₂ <(1/2) × In the case of CF ₄ , the process selection unit selects the second process.
(E) Even if the He concentration is less than the third threshold value and the N ₂ or CF ₄ concentration is less than the second threshold value, the process selection unit may perform control to select the third process. Good.
In the above invention, the “third threshold value” is, for example, an arbitrary value between 0.5% and 1.5%, preferably an arbitrary value between 0.8% and 1.2%, more preferably 1.0%.

The concentration of CF ₄ , N ₂ and He can also be measured as impurities in the exhaust gas. The CF ₄ and N ₂ concentrations in the exhaust gas are assumed to be in the range of ₁ ppm to 500 ppm, and the He concentration is assumed to be in the range of 0.01 to 5.0%.
When the CF ₄ or N ₂ concentration is, for example, 100 ppm or more, or the He concentration is, for example, 1% or more, the laser intensity decreases, so the CF ₄ or N ₂ concentration is not less than the first threshold (for example, 100 ppm). When the He concentration is equal to or higher than a third threshold (for example, 1%), the process selection unit selects the first process, and the first process discharges exhaust gas from the system through the discharge line.
Even if the He concentration is less than the third threshold, and the CF ₄ and N ₂ concentrations are greater than a second threshold (eg, 10 ppm) that is less than the first threshold and less than the first threshold, the N ₂ concentration Is more than twice the CF ₄ concentration, the amount of ions generated in the decomposition process of the decomposition apparatus is advantageously the amount of nitrogen ions relative to the amount of carbon ions. In this case, nitrogen ions decomposed and generated by the decomposition apparatus preferentially react with oxygen or oxygen ions contained in the exhaust gas rather than carbon ions to generate nitrogen oxides. Therefore, when the N ₂ concentration of CF ₄ concentration twice or more by selecting the processing selection unit first processing, the first processing is discharged from the system the exhaust gas by the discharge line.
On the other hand, if the He concentration is less than the third threshold, the CF ₄ and N ₂ concentrations are greater than or equal to the second threshold and less than the first threshold, and the N ₂ concentration is less than twice the CF ₄ concentration, Since the decomposition is possible and the amount of nitrogen oxides generated by this decomposition is small, the second treatment is selected. In the second treatment, the exhaust gas is introduced into the cracking device through the cracking and removal treatment line.
If the He concentration is less than the third threshold and the CF ₄ and N ₂ concentrations are less than the second threshold, the third process is selected. In the third treatment, the decomposition apparatus is bypassed, and the exhaust gas is directly introduced into the subsequent membrane separation apparatus.

In the above invention, a fluorine compound removal unit, an impurity concentration measurement unit, a buffer tank, a decomposition device, and a decomposition byproduct removal unit may be arranged in this order in the decomposition removal processing line.
In the above invention, impurities are removed from the exhaust gas (referred to as the first purified gas) treated in the decomposition byproduct removal unit.
In the above invention, the excimer laser oscillation device or oscillation is performed by using the exhaust gas (referred to as the second purified gas) processed by each separation membrane device and the first and second impurity removal devices as a recycle gas (additional gas may be mixed). Return to chamber.

Each bypass line is provided with a gate valve. The gate valve is opened during the bypass process.
Each of the separation membrane devices may have a gate valve at least on the upstream side thereof.
The upstream oxygen removal unit may have a gate valve at least on the upstream side thereof.
Said 1st, 2nd impurity removal apparatus (oxygen removal part and / or getter) may have a gate valve at least in the upstream.

(Method)
The laser gas recycling method of the present invention is a laser gas recycling method for removing a predetermined impurity from an exhaust gas discharged from an excimer laser device or an excimer laser oscillation chamber to obtain a purified gas (recycle gas) containing high-purity neon gas as a main component. Because
A Ne separation step of removing a rare gas for excitation (for example, krypton, argon, xenon) other than neon from the gas to be treated with a separation membrane;
A recovery step of recovering non-permeate gas (neon gas containing a high concentration rare gas) separated by a separation membrane and / or a discharge step of discharging out of the system;
An impurity removal step of removing predetermined impurities from the high-concentration neon-containing gas that has passed through the separation membrane;
A recycle gas generation step of mixing a predetermined additive gas with the purified gas (high purity neon gas) purified in the impurity removal step so as to generate a necessary laser gas according to the excimer laser oscillation device.

In another laser gas recycling method of the present invention, a laser gas for removing a predetermined impurity from an exhaust gas discharged from an excimer laser device or an oscillation chamber of an excimer laser to obtain a purified gas (recycle gas) mainly composed of high-purity neon gas. A recycling method,
A second separation membrane step of removing a rare gas for excitation (for example, xenon) other than argon and neon from the gas to be treated with a separation membrane;
A recovery step of recovering non-permeate gas (high-concentration xenon-containing neon gas) separated by a separation membrane and / or a discharge step of discharging out of the system;
An impurity removal step of removing predetermined impurities from the permeated gas that has passed through the separation membrane;
A recycle gas generation step of mixing an additive gas with the purified gas (high purity neon gas) purified in the impurity removal step so as to generate a necessary laser gas according to the excimer laser oscillation apparatus.

It is a figure which shows the structural example of the laser gas recycling system of Embodiment 1. FIG. It is a figure which shows the structural example of the laser gas recycling system of Embodiment 2. FIG. It is a figure which shows the structural example of a separation membrane part. It is a figure which shows the structural example of a separation membrane part. It is a figure which shows the structural example of a separation membrane part.

(Embodiment 1)
The laser gas recycling system 1 of the first embodiment shown in FIG. 1 includes a halogen-based gas purification unit 200, a gas purification unit 100, a recycle gas supply unit 310, and an additive gas supply unit 320. The laser gas recycling system 1 according to the first embodiment is connected outside the plurality of excimer laser oscillation devices 400.
Each excimer laser oscillator 400 is, for example, a krypton / fluorine (KrF) excimer laser oscillator, an argon / fluorine (ArF) excimer laser oscillator, or an argon / xenon / fluorine (Ar / Xe / F) excimer laser oscillator. . In this embodiment, the exhaust gas is sent from one or more excimer laser oscillators 400 to the laser gas recycling system 1 and supplied to the one or more excimer laser oscillators 400 again as a recycled gas. A single excimer laser oscillation device 400 may be connected to the laser gas recycling system 1.

The excimer laser oscillation device 410 includes an oscillation chamber in which a laser gas having a halogen gas (for example, fluorine), a rare gas (for example, krypton, argon, or xenon) and a buffer gas (for example, neon, helium, or chlorine) is filled. 402.
The oscillation chamber 402 is filled with a predetermined pressure and a predetermined amount of laser gas. In this state, the high voltage pulse generator 401 applies a high voltage pulse discharge to at least a pair of electrodes with respect to the laser gas (excitation gas) in the oscillation chamber 402, whereby an excimer in an excited state is generated and induced. Light is obtained by causing emission. The light emitted from the oscillation chamber 402 is adjusted to a specific wavelength width by a not-shown narrowband module. The light returned from the narrow band module to the oscillation chamber 402 is amplified by passing between the pair of electrodes. The narrowband module and the output mirror are connected by an optical path line so as to pass through the oscillation chamber 402, and each time light reciprocates between the narrowband module and the output mirror, it passes between the pair of electrodes, Light is amplified. The light that has passed through the output mirror is output as an output laser beam, for example, to an exposure apparatus. Here, the function of the resonator is realized by the band- narrowing module and the output mirror, but the function of the resonator may be realized by another configuration.

The laser gas filled in the oscillation chamber 402 includes, for example, a buffer gas (for example, 90 to 95%) such as neon gas or helium, a rare gas (Kr, Ar, Xe) (for example, 5 to 9%), and a halogen gas ( F ₂ ) (for example, 1 to 5%). For example, examples of the excitation gas include KrF, ArF, XeF, and Ar / XeF.
In this embodiment, what is returned to the oscillation chamber 402 as a recycle gas is a main component buffer gas (for example, neon) containing a rare gas (for example, krypton, argon, or argon / xenon) having the same component as the laser gas component. The halogen-containing main component buffer gas and the recycle gas may be mixed and then sent to the oscillation chamber 402.
The excimer laser oscillation device 400 includes a first laser gas supply line for feeding the first laser gas into the oscillation chamber 402, a second laser gas supply line for feeding the second laser gas, and a recycle gas line for feeding the recycle gas. You may do it.
The first laser gas may be a halogen gas-containing main component buffer gas or a rare gas and halogen gas-containing main component buffer gas.
The second laser gas may be a halogen gas-containing main component buffer gas or a rare gas and halogen gas-containing main component buffer gas.
The first laser gas supply line and the second laser gas supply line are each provided with a control valve, a gas flow meter, a gas flow rate adjusting unit, a pressure gauge, a pressure adjusting unit (for example, a pressure reducing valve), and supply laser gas to the oscillation chamber 402 In doing so, they are controlled by the control device, and a laser gas having a predetermined pressure and a predetermined flow rate is supplied to the oscillation chamber.

In FIG. 1, the laser gas is supplied from the supply container 10 to the excimer laser oscillation device 400 through the supply line L1 at a predetermined pressure (first pressure). The supply line L1 is provided with a constant flow valve CFV1 and a gate valve GV1. In addition, it is not limited to this, One or more various valves may be provided, and the valve does not need to be provided. A gas flow rate adjustment unit and a gas pressure adjustment unit may be arranged in the supply line L1. The “first pressure” is set according to the specification of the excimer laser oscillation device 400, and is, for example, 300 KPa to 700 KPa.
The supply line L1 is connected to a supply pipe (not shown) connected to each excimer laser transmitter. Although not shown, exhaust gas pipes (not shown) connected to the respective excimer laser transmitters are connected to the exhaust gas line L2. Further, one or more predetermined valves may be provided in the supply pipe, the exhaust gas pipe, the supply line L1, and the exhaust gas line L2.

(Halogen gas purification unit)
The halogen-based gas purification unit 200 removes predetermined impurities in the exhaust gas discharged from the oscillation chamber 402.
The exhaust gas discharged from the oscillation chamber 402 is sent to the halogen-based gas purification unit 200 through the exhaust gas line L2. The exhaust gas is discharged at a second pressure that is greater than atmospheric pressure and less than or equal to the first pressure. This second pressure is also set according to the specifications of the excimer laser oscillation device 400. Note that a configuration may be employed in which a discharge pump (not shown) is disposed in the exhaust gas line L2 to execute (or accelerate) exhaust gas discharge.
The “second pressure” is, for example, 50 to 100 KPa. The exhaust gas exhausted contains impurities. Examples of the impurities include nitrogen, oxygen, carbon monoxide, carbon dioxide, water, CF ₄ , He, CH _{4 and the} like.
The control device (not shown) of the laser gas recycling system 1 or the excimer laser oscillation device 400 has a laser gas supply / discharge control unit (not shown). The laser gas supply / discharge control unit includes a control valve, a gas flow meter, and a gas flow rate. The adjustment unit, the gas pressure reducing valve, etc. are controlled, and laser gas (exhaust gas) is discharged from the oscillation chamber 402 according to a predetermined rule (for example, a regular timing based on the operation time), and an amount corresponding to the discharged amount Either one or both of laser gas and recycle gas (mixed gas of new laser gas and recycle gas) is supplied.

The exhaust gas line L2 is also referred to as a decomposition removal treatment line in the halogen-based gas purification unit 200.
First, the exhaust gas is sent to the fluorine compound removing unit 201, and the fluorine compound that is part of the impurities is removed.
Next, the exhaust gas is sent to the buffer space BT1 and stored so that the exhaust gas becomes a certain amount. The buffer space BT1 has a function of storing a predetermined amount of exhaust gas and stably measuring impurities by an impurity concentration detector 202 described later.
The impurity concentration in the exhaust gas is measured by the impurity concentration measuring unit 201 disposed inside the buffer space BT1. Here, for example, the concentration of CF ₄ as the impurity is measured. As the impurity concentration detection unit 201, for example, gas chromatography, a heat conduction type concentration sensor, a semiconductor type concentration sensor, or the like can be used.

  A discharge line L21 for discharging the exhaust gas from the buffer space BT1 to the outside air is provided. The discharge line L21 includes, for example, a pipe, a vent device for discharging outside air, and a constant flow valve CFV2 (may be another type of valve).

  A bypass line L23 branches from the decomposition removal processing line L22 downstream of the buffer space BT1. The bypass line L23 has, for example, a pipe and an automatic opening / closing gate valve GB3.

  The decomposition / removal processing line L22 includes, for example, a pipe, a gas flow rate measurement unit MFC1, and a constant flow valve CFV3. The front-rear arrangement of the gas flow rate measurement unit MFC1 and the constant flow valve CFV3 is not particularly limited, and may be the reverse arrangement of FIG. The gas flow rate measurement unit MFC1 may be a mass flow controller or a mass flow meter. The replacement time determination unit (not shown) calculates the amount of impurities based on the measurement value of the gas flow rate measurement unit MFC1 and the measurement value of the impurity concentration detection unit 201, and the predetermined reactant of the decomposition byproduct removal unit 205 You may ask for the replacement time. The required replacement time may be output to an input / output interface or the like to notify the operator.

Further, a buffer container 203 is disposed in the decomposition / removal processing line L22 on the downstream side of the gas flow rate measuring unit MFC1, and a predetermined amount of exhaust gas is stored here. On the downstream side of the buffer container 203, a decomposition apparatus 204 that decomposes fluorocarbon (CF ₄ ), which is a part of impurities, into a decomposition byproduct is disposed. In the present embodiment, the decomposition apparatus 204 is an apparatus that irradiates exhaust gas with excimer laser light.
A decomposition by-product removal unit 205 is disposed downstream of the decomposition apparatus 204. In the present embodiment, the decomposition by-product is, for example, a fluorine compound, and the decomposition by-product generated by the decomposition apparatus 204 is reacted with a predetermined reactant (for example, a metal-based reactant or a gas absorption-type reactant). To remove from the exhaust gas. The exhaust gas that has passed through the decomposition byproduct removal unit 205 is referred to as a first purified gas. The first purified gas is sent to the gas purification unit 100 through the gas processing line L3.
In another embodiment, the gas flow rate measurement unit MFC1 may or may not be present. Further, the fluorine compound removing unit 201 may or may not be provided.

The determination of process selection in the present embodiment is as follows.
The impurity concentration detector 202 measures the concentration of CF _{4 in} the exhaust gas. In this case, when the concentration of CF ₄ is equal to or higher than the first threshold value (for example, 100 ppm), the process selection unit (not shown) selects the first process, and the second threshold value where the concentration of CF ₄ is smaller than the first threshold value. When the value is greater than (for example, 10 ppm) and less than the first threshold value, the process selection unit selects the second process, and when the CF ₄ concentration is less than the second threshold value, the process selection unit selects the third process. .

As another embodiment, the impurity concentration detector 202 measures the concentrations of CF ₄ , N ₂ and He in the exhaust gas. In this case,
(A) The He concentration is a third threshold value (for example, 1.0%) or more,
(B) either CF ₄ or N ₂ is greater than or equal to the first threshold (eg, 100 ppm), or
(C) The He concentration is less than the third threshold value, and either CF ₄ or N ₂ is greater than or equal to the second threshold value (for example, 10 ppm) and less than the first threshold value, and the concentration relationship is N ₂ > (1 / 2) in the case of × CF _4, the processing selection unit selects the first process.
(D) In the case where the He concentration is less than the third threshold, the concentration of N ₂ or CF ₄ is greater than or equal to the second threshold and less than the first threshold, and the magnitude relationship of the concentrations is N ₂ <(1/2) × In the case of CF ₄ , the process selection unit selects the second process.
(E) When the He concentration is less than the third threshold value and the N ₂ or CF ₄ concentration is less than the second threshold value, the process selection unit selects the third process.

  The control device, process selection unit, control unit for various valves, and replacement time determination unit have hardware such as a CPU (or MPU), circuit, firmware, memory for storing software programs, etc. The structure which operate | moves by cooperation may be sufficient.

  As another embodiment, the halogen-based gas purification unit 200 may not be provided, or the decomposition / removal processing line L22 may be omitted, and the discharge line L21 and the bypass line L23 may be provided. The bypass line L23 may be provided. However, the discharge line L21 and the disassembly / removal processing line L22 may be provided.

(Gas purification unit)
The gas purification unit 100 removes predetermined impurities from the exhaust gas (first purified gas) sent from the halogen-based gas purification unit 200 to obtain a recycled gas (high purity neon gas). The gas processing line L3 includes, for example, piping, one or more constant flow valves CFV4 and CFV5, and automatic open / close valves (not shown).
In the gas processing line L3, a first recovery container CC1 for storing the first purified gas, a pressure gauge PG12 for measuring the internal pressure (gas pressure) of the first recovery container CC1, and a first flowing downstream thereof. A back pressure regulator BPR1 for maintaining the pressure of the purified gas at a predetermined pressure, a second recovery container CC2 for storing the first stored gas, and a pressure gauge for measuring the internal pressure (gas pressure) of the second recovery container CC1 PG12, a first compressor CP1 for feeding the first purified gas downstream (or increasing the pressure to a predetermined pressure), and a predetermined noble gas (noble gas for excitation other than neon ( The second purified gas (high-concentration neon-containing gas (here, “high-concentration” refers to neon gas in the first purified gas before being introduced into the Ne separation membrane device) after separating krypton, argon, and xenon. Means a Ne separation membrane device 110 for obtaining) and a second for feeding the second purified gas downstream (or for increasing the pressure to a predetermined pressure). The compressor CP2 and an impurity removing device 120 for removing a predetermined impurity from the second purified gas and obtaining a purified gas of high purity neon gas (first recycled gas) are arranged in this order.
In the present embodiment, both the first recovery container and the second recovery container may be present, but either one may be present or both may be absent depending on the pipe internal volume. The pressure gauges PG12 and PG13 may or may not be present.
In the present embodiment, both the first compressor CP1 and the second compressor CP2 may be provided, but only one of them may be provided. The second compressor CP2 may be disposed downstream from the impurity removing device 120.

As another embodiment, on the upstream side of the Ne separation membrane device 110, a heat exchanger, an adjustment unit for adjusting the flow rate of the first purified gas, a flow meter for measuring the flow rate of the first purified gas, A pressure adjusting unit that adjusts the pressure may be provided. The heat exchanger reduces the temperature of the first purified gas to a predetermined temperature. The gas temperature (for example, 60 to 80 ° C.) increased and increased by the compressor CP1 can be reduced to a predetermined temperature (for example, 15 to 35 ° C.). Reduce gas temperature to a range.
Further, as another embodiment, an adjustment unit that adjusts the flow rate of the first recycle gas, a flow meter that measures the flow rate of the first recycle gas, and the pressure of the first recycle gas are adjusted downstream of the first impurity removing device 120. A pressure adjusting unit may be provided.

The compressor CP1 increases the pressure of the first purified gas to the third pressure. The third pressure is, for example, a pressure higher by 50 KPa to 150 KPa than the first pressure. The pressure control unit (not shown) may control the pressure of the first purified gas based on a measurement value of a pressure gauge incorporated in the compressor CP1 or a pressure gauge arranged downstream of the compressor CP1.
The compressor CP2 increases the pressure of the second purified gas to the third pressure. The pressure control unit (not shown) may control the pressure of the second purified gas based on a pressure gauge incorporated in the compressor CP2 or a measurement value of a pressure gauge disposed downstream of the compressor CP2. The compressor CP1 can be eliminated, and the second purified gas can be sent downstream by the compressor CP2.

(Separation membrane device)
An embodiment of the separation membrane device 110 will be described with reference to FIGS.

(Series type)
The separation membrane device 110 of FIG. 3 has a configuration in which three stages of separation membranes M1, M2, and M3 are arranged in series.
In the line from the supply line F1 of the first separation membrane M1 connected to the first purified gas line L3 to the permeation gas line F11 through which the permeated gas permeated through the first separation membrane M1 passes, the buffer tank BT11, the compressor CP11, One separation membrane M1, a pressure adjustment BPR11, a compressor VP11, and a flow rate adjustment unit MFM11 are provided as a unit U11. The permeate gas line F11 is connected to the supply line F2 via the buffer tank BT21.
The non-permeate gas separated by the first separation membrane M1 is sent to the exhaust / recovery line L41 through the non-permeate gas line F12 and exhausted or recovered. A pressure adjusting unit BPR12 and a flow rate adjusting unit MFM12 are provided as a unit U12 in the non-permeating gas line F12.

In the line from the supply line F2 of the second separation membrane M2 to the permeation gas line F21 through which the permeated gas permeated through the second separation membrane M2 passes, the buffer tank BT21, the compressor CP21, the second separation membrane M2, the pressure adjustment BPR21, the compressor A VP21 and a flow rate adjustment unit MFM21 are provided as the unit U21. The permeate gas line F21 is connected to the supply line F3 via the buffer tank BT31.
The non-permeable gas separated by the second separation membrane M2 passes through the non-permeable gas line F22, is sent to the supply line F1 through the buffer tank BT11, and is supplied to the first separation membrane M1. A pressure adjustment unit BPR22 and a flow rate adjustment unit MFM22 are provided as a unit U22 in the non-permeating gas line F22.

In the line from the supply line F3 of the third separation membrane M3 to the permeation gas line F31 through which the permeated gas permeated through the third separation membrane M3 passes, the buffer tank BT31, the compressor CP31, the third separation membrane M3, the pressure adjustment BPR31, the compressor A VP31 and a flow rate adjustment unit MFM31 are provided as the unit U31. The permeate gas line F31 is connected to the second purified gas line L4 via the flow rate adjustment unit MFM31.
The non-permeable gas separated by the third separation membrane M3 passes through the non-permeable gas line F32, is sent to the supply line F2 via the buffer tank BT21, and is supplied to the second separation membrane M2. A pressure adjusting unit BPR32 and a flow rate adjusting unit MFM32 are provided as a unit U32 in the non-permeating gas line F32.

In the serial type of FIG. 3, the buffers BT11, 21, and 31 may or may not be provided.
FIG. 3 shows a three-stage series configuration, but is not limited thereto, and one or more separation membranes may be arranged in series according to the rare gas to be separated.

(Circulation type)
In the separation membrane device 110 of FIG. 4, three stages of separation membranes M1, M2, and M3 are arranged in series, and the permeated gas from the third separation membrane M3 in the final stage is supplied to the first separation membrane M1 in the foremost stage. This is a configuration. Since the same reference numerals as those in FIG. 3 have the same configuration, description thereof may be omitted. Features different from the configuration of FIG. 3 will be described in detail.
The circulation type can reduce the number of separation membrane stages as compared with the series type on condition that the same separation performance can be exhibited, but requires other configuration and control related to circulation. The configuration arranged in the excimer laser oscillation system (for example, in the housing) is preferably a circulation type in terms of downsizing the apparatus space.

  The permeate gas line F31 of the third separation membrane M3 is connected to the second purified gas line L4 via the flow rate adjustment unit MFM31. Further, a return line R1 branched from the second purified gas line L4 and connected to the first purified gas line L3 (or the supply line F1 of the first separation membrane M1) is provided. A valve (not shown) is provided in the return line R1 and / or the second purified gas line L4, and the second purified gas (treated gas) is circulated by opening and closing the valve, and / or a downstream impurity removing device. It is the structure which controls to send to 120.

In the separation membrane device 110 of FIG. 5, three stages of separation membranes M1, M2, and M3 are arranged in series, and the permeated gas from the third separation membrane M3 in the final stage is supplied to the second separation membrane M2 in the previous stage. It is a configuration. Since the same reference numerals as those in FIG. 3 have the same configuration, description thereof may be omitted. Features different from the configuration of FIG. 3 will be described in detail.
In the line from the supply line F1 of the first separation membrane M1 to the permeation gas line F11 through which the permeated gas permeated through the first separation membrane M1 passes, the buffer tank BT11, the compressor CP11, the first separation membrane M1, the pressure adjustment BPR11, the compressor A VP11 and a flow rate adjustment unit MFM11 are provided as the unit U11. The permeate gas line F11 is connected to the supply line F2 via the buffer tank BT21.
The non-permeate gas separated by the first separation membrane M1 is sent to the exhaust / recovery line L41 through the non-permeate gas line F12 and exhausted or recovered. A pressure adjusting unit BPR12 and a flow rate adjusting unit MFM12 are provided as a unit U12 in the non-permeating gas line F12.

In the line from the supply line F2 of the second separation membrane M2 connected to the first purified gas line L3 to the permeation gas line F21 through which the permeated gas permeated through the second separation membrane M2 passes, the buffer tank BT21, the compressor CP21, the first A two-separation membrane M2, a pressure adjustment BPR21, a compressor VP21, and a flow rate adjustment unit MFM21 are provided as a unit U21. The permeate gas line F21 is connected to the supply line F3 via the buffer tank BT31.
The non-permeable gas separated by the second separation membrane M2 passes through the non-permeable gas line F22, is sent to the supply line F1 through the buffer tank BT11, and is supplied to the first separation membrane M1. A pressure adjustment unit BPR22 and a flow rate adjustment unit MFM22 are provided as a unit U22 in the non-permeating gas line F22.

  The permeate gas line F31 of the third separation membrane M3 is connected to the second purified gas line L4 via the flow rate adjustment unit MFM31. Further, a return line R2 branched from the second purified gas line L4 and connected to the first purified gas line L3 (or the supply line F2 of the second separation membrane M2) is provided. A valve (not shown) is provided in the return line R2 and / or the second purified gas line L4, and the second purified gas (processed gas) is circulated by opening and closing the valve, and / or a downstream impurity removing device. It is the structure which controls to send to 120.

4 and 5, the buffers BT11, 21, and 31 may or may not be provided.
4 and 5 have a three-stage structure, but the present invention is not limited to this, and a structure including one or three or more separation membranes may be used depending on the rare gas to be separated.

(Example of separating krypton from krypton-containing neon gas)
The flow rate of the gas to be processed that passes through the first, second, and third separation membranes M1, M2, and M3 is set to the upstream compressors CP11, 21, and 31 that are arranged upstream of the separation membranes, and the pressure that is arranged downstream thereof. The adjusting units BPR11, 21, 31 and the downstream compressors VP11, 21, 31 are controlled so as to generate a predetermined pressure difference (upstream pressure-downstream pressure). You may comprise so that this pressure difference may become larger than a krypton separation set value, or it may exist in a predetermined range on the basis of the krypton separation set value. The krypton separation set value may be determined based on experimental results, may be updated by actual operation, or may be set based on the type and size of the separation membrane.

(Example of separation of xenon from xenon-containing neon gas)
The flow rate of the gas to be processed that passes through the first, second, and third separation membranes M1, M2, and M3 is set to the upstream compressors CP11, 21, and 31 that are arranged upstream of the separation membranes, and the pressure that is arranged downstream thereof. The adjusting units BPR11, 21, 31 and the downstream compressors VP11, 21, 31 are controlled so as to generate a predetermined pressure difference (upstream pressure-downstream pressure). You may comprise so that this pressure difference may become larger than a xenon separation set value, or it may exist in a predetermined range on the basis of the xenon separation set value. The xenon separation set value may be determined based on experimental results in advance, may be updated by actual operation, or may be set based on the type and size of the separation membrane.

(Example of separating argon from argon-containing neon gas)
The flow rate of the gas to be processed that passes through the first, second, and third separation membranes M1, M2, and M3 is set to the upstream compressors CP11, 21, and 31 that are arranged upstream of the separation membranes, and the pressure that is arranged downstream thereof. The adjusting units BPR11, 21, 31 and the downstream compressors VP11, 21, 31 are controlled so as to generate a predetermined pressure difference (upstream pressure-downstream pressure). You may comprise so that this pressure difference may become larger than an argon separation setting value, or it may exist in a predetermined range on the basis of the argon separation setting value. The argon separation set value may be determined based on a result of an experiment in advance, may be updated by actual operation, or may be set based on the type and size of the separation membrane.

(Example of separating argon / xenon from neon gas containing argon / xenon)
The flow rate of the gas to be processed that passes through the first, second, and third separation membranes M1, M2, and M3 is set to the upstream compressors CP11, 21, and 31 that are arranged upstream of the separation membranes, and the pressure that is arranged downstream thereof. The adjusting units BPR11, 21, 31 and the downstream compressors VP11, 21, 31 are controlled so as to generate a predetermined pressure difference (upstream pressure-downstream pressure). You may comprise so that this pressure difference may become larger than an argon xenon separation set value, or it may become in a predetermined range on the basis of the argon xenon separation set value. The argon / xenon separation set value may be determined based on experimental results, may be updated by actual operation, or may be set based on the type and size of the separation membrane. When the separation factor ratio of argon to neon gas and the separation factor ratio of xenon differ depending on the type of separation membrane, an argon / xenon separation set value based on components that are difficult to separate is set.

(Example of separating xenon from neon gas containing argon and xenon)
When separating xenon as a non-permeating gas without separating argon from neon gas containing argon / xenon, use a separation membrane that is difficult to separate argon, and use xenon / xenon to separate xenon without separating argon. The flow rate of the contained neon gas is determined by the upstream compressors CP11, 21, 31 disposed upstream of the separation membranes, the pressure adjusting units BPR11, 21, 31 disposed downstream thereof, and the downstream compressors VP11, 21, 31. The pressure difference (upstream pressure-downstream pressure) is controlled. The predetermined pressure difference is a pressure difference at which xenon separates without separation of argon, and may be determined based on experimental results, or may be updated by actual operation, based on the type and size of the separation membrane. It may be set.

(Impurity removal equipment)
The first impurity removing device 120 is connected to the second purified gas line L4 via the second compressor CP2. The first impurity removing device 120 includes a first removing unit 121 and a second removing unit 122.
The first removal unit 121 is a deoxygenation device filled with a manganese oxide reactant or a copper oxide reactant that removes oxygen from the second purified gas. Manganese oxide reactants include reactants such as manganese monoxide MnO, manganese dioxide MnO ₂ reactants, and manganese oxide reactants based on adsorbents. Examples of the copper oxide reactant include a reactive agent such as copper oxide CuO and a copper oxide reactive agent based on an adsorbent.
The second purified gas that has passed through the first removal unit 121 is sent to the second removal unit 122 through the pipe L5.

Impurities in the second purified gas that have passed through the first removal unit 121 are components excluding impurities that are most contained in the exhaust gas components. For example, nitrogen, carbon monoxide, carbon dioxide, water, CF ₄ , CH ₄ and He. CF ₄ may be removed (partially removed or completely removed) by the halogen-based gas removal unit 200, or may be bypassed and sent to the gas purification unit 100.
The second removal unit 122 is a getter filled with a chemical adsorbent that removes impurities (for example, nitrogen, carbon monoxide, carbon dioxide, water, CH ₄ ) other than oxygen.
The purified gas (referred to as the second purified gas or the first recycled gas) that has passed through the second removal unit 122 is a high-purity neon gas. The first recycle gas is sent to the first buffer tank BT311 of the recycle gas supply unit 310 through the pipe L6.

(Recycle gas supply department)
The first recycle gas in the first buffer tank BT311 may join the supply line L1 as the recycle gas through the recycle line L6 and may be sent to the oscillation chamber 402 of the excimer laser oscillation device 400. As described later, the first recycle gas may be mixed with the additive gas and then sent to the excimer laser oscillation device.
The recycle line L6 constituting the recycle gas supply unit 310 includes a first buffer tank BT311, a back pressure valve BPV311, a pressure gauge PG311, a mass flow controller MFC311, a constant flow valve CFV311 (other types of valves), and a second buffer tank BT310. The constant flow valve CFV 312 (which may be another type of valve) is arranged in this order.
The pressure gauge PG311 may or may not be present.
The second buffer tank BT312 may or may not be present.
The constant flow valves CFV 311 and CFV 312 may be other valves, respectively, and either one or both may be omitted.
The mass flow controller MFC 311 and the back pressure valve BPV 311 may both be present, or one of them may be present.

A back pressure valve BPV 311 and a mass flow controller MFC 311 are arranged on the downstream side of the first buffer tank BT1.
The pressure control unit (not shown) controls the pressure of the first recycle gas based on the measurement value of the pressure gauge PG311 or the back pressure valve BPV311. Since the pressure of the first recycle gas in the first buffer tank BT311 is the third pressure, it is preferable to reduce the pressure to the same pressure (first pressure) as the laser gas in the oscillation chamber 402 or slightly higher than that.

  The mass flow controller MFC 311 controls the flow rate of the first recycle gas. Thereby, the supply amount of the 1st recycle gas sent into supply line L1 can be controlled uniformly. Note that the mass flow controller MFC 311 may be only a gas flow meter. The arrangement of the mass flow controller MFC 311 or the gas flow meter and the back pressure valve BPV 311 may be reversed.

(Additional gas supply unit)
An additive gas line L320 that merges with the recycle gas line L6 is provided downstream of the constant flow valve CFV 311 or upstream of the second buffer tank BT312. The additive gas line L320 has a container S321 filled with a mixed gas such as a buffer gas (for example, neon), an excitation rare gas, and halogen, a safety valve SV321, a pressure gauge PG321, a back pressure valve (pressure adjusting unit) BPV321, and a pressure gauge PG322. The mass flow controller MFC321 and the constant flow valve CFV321 are arranged in this order.
One or both of the pressure gauges PG321 and PG322 may or may not be present.
The constant flow valve CFV 321 may or may not be another valve.
The mass flow controller MFC 321 and the back pressure valve BPV 321 may both be present, or one of them may be present.

  The pressure control unit (not shown) may control the pressure of the additive gas based on the measured value of the pressure gauges PG321 and / or 322 of the additive gas line L320 or the back pressure valve BPV321. When the addition pressure in the container S321 is higher than the first pressure, the pressure is reduced to the first pressure.

The mass flow controller MFC321 controls the flow rate of the additive gas. Thereby, the supply amount of the additive gas sent to the confluence point P of the first recycle line L6 can be controlled to be constant. Note that the mass flow controller MFC 321 may be only a gas flow meter. Further, the arrangement of the mass flow controller MFC 321 or the gas flow meter and the back pressure valve BPV 321 may be reversed.
The flow rate of the additive gas is controlled by the mass flow controller MFC 321, and the flow rate of the first recycle gas is controlled by the mass flow controller MFC 311 and mixed so as to have the same component composition as the laser gas in the supply container 10.

  A space for mixing the first recycle gas and the additive gas or a gas mixing device is preferably provided at the junction point P, and the buffer tank BT312 is provided in the subsequent stage so that the mixed gas is stabilized at a constant concentration. It may be arranged.

(Embodiment 2)
FIG. 2 shows a laser gas recycling system 1 according to the second embodiment. The description of the configuration similar to that of the first embodiment (FIG. 1) may be omitted or simplified.
In the gas purification unit 100, a booster CP3 is disposed in the exhaust gas / recovery line L41 instead of the first compressor CP1.
In particular, with this configuration, it is preferable to separate xenon from the argon / xenon-containing neon gas as compared with the first embodiment.

(Another embodiment)
The laser gas recycling system 1 of the first and second embodiments may be disposed in the casing of the excimer laser oscillation device 400, and a part thereof (the halogen-based gas purification unit 200, the gas purification unit) in the casing of the excimer laser oscillation device. The configuration of any one of the unit 100 and the recycle gas supply unit 310 or two or more thereof may be arranged.
Further, when the laser gas recycling system 1 is arranged separately from the excimer laser oscillation device 400, the laser gas recycling system 1 performs a recycling process on the exhaust gas discharged from one excimer laser oscillation device or one or more excimer laser oscillation devices. You may go.

In the first and second embodiments, the halogen-based gas purification unit 200 may or may not be provided.
In the first and second embodiments, the halogen-based gas purification unit 200 may not include the bypass line L23 and / or the decomposition / removal processing line.

(Laser gas recycling method)
The laser gas recycling method is a laser gas recycling method for removing a predetermined impurity from exhaust gas discharged from an excimer laser device or an excimer laser oscillation chamber to obtain a purified gas mainly composed of high-purity neon gas,
A Ne separation step of removing a rare gas for excitation (krypton, argon, xenon) other than neon from the gas to be treated with a separation membrane;
A recovery step of recovering non-permeate gas (neon gas containing a high concentration rare gas) separated by a separation membrane and / or a discharge step of discharging out of the system;
An impurity removal step of removing predetermined impurities from the high-concentration neon-containing gas that has passed through the separation membrane;
A recycle gas generation step of mixing a predetermined additive gas with the purified gas (high purity neon gas) purified in the impurity removal step so as to generate a necessary laser gas according to the excimer laser oscillation device.
Another laser gas recycling method is a laser gas recycling method for removing a predetermined impurity from exhaust gas discharged from an excimer laser device or an excimer laser oscillation chamber to obtain a purified gas mainly composed of high-purity neon gas,
A second separation membrane step of removing a rare gas for excitation (xenon) other than argon and neon from the gas to be treated by a separation membrane;
A recovery step of recovering non-permeate gas (high-concentration xenon-containing neon gas) separated by a separation membrane and / or a discharge step of discharging out of the system;
An impurity removal step of removing predetermined impurities from the permeated gas that has passed through the separation membrane;
A recycle gas generation step of mixing an additive gas with the purified gas (high purity neon gas) purified in the impurity removal step so as to generate a necessary laser gas according to the excimer laser oscillation apparatus.
The laser gas recycling method may further include an impurity concentration measurement step for measuring the impurity concentration in the exhaust gas.
The laser gas recycling method may further include a fluorine compound removal step of removing a fluorine compound that is a kind of impurity, before the Ne separation step.
In the laser gas recycling method, before the Ne separation step, a decomposition step of decomposing fluorocarbon (CF4 or the like), which is a kind of impurity, into a decomposition by-product, and a decomposition by-product generated in the decomposition step A decomposition by-product removal step of reacting with a predetermined reactant and removing it from the exhaust gas may be included.

(Separation membrane device)
The separation membrane device removes rare gases other than neon (krypton, argon, xenon) from the exhaust gas discharged from the excimer laser oscillation device using a krypton-containing neon gas, an argon / xenon-containing neon gas, or a xenon-containing neon gas laser gas, It has one or more separation membranes for purifying high-purity neon gas.
The other separation membrane device removes rare gas (xenon) other than argon and neon from the exhaust gas discharged from the excimer laser oscillation device using the laser gas of argon / xenon-containing neon gas, and purifies the argon-containing high-purity neon gas. It has one or more separation membranes.

DESCRIPTION OF SYMBOLS 1 Laser gas recycling system 100 Gas purification part 110 Separation membrane apparatus 120 Impurity removal apparatus 200 Halogen type gas purification part 310 Recycle gas supply part 320 Addition gas supply part 400 Excimer laser oscillation apparatus 402 Oscillation chamber

Claims (9)

A laser gas recycling system for removing a predetermined impurity from an exhaust gas discharged from an excimer laser device or an excimer laser oscillation chamber to obtain a purified gas mainly composed of high-purity neon gas,
A Ne separation membrane device for membrane separation of a rare gas for excitation other than neon from a gas to be treated;
A first impurity removing device that removes predetermined impurities from the treated gas that has permeated or not permeated in the Ne separation membrane device;
Laser gas recycling system with A laser gas recycling system for removing a predetermined impurity from an exhaust gas discharged from an excimer laser device or an excimer laser oscillation chamber to obtain a purified gas mainly composed of high-purity neon gas,
An Ar / Ne separation membrane device for removing a rare gas for excitation other than argon and neon from the gas to be treated;
A second impurity removing device for removing predetermined impurities from the processed gas that has permeated or not permeated by the Ar / Ne separation membrane device;
Laser gas recycling system with   3. The laser gas recycling system according to claim 1, further comprising a recycle gas generation unit configured to mix a predetermined additive gas with the purified gas so as to generate a necessary laser gas according to the excimer laser oscillation device.   3. The laser gas recycling system according to claim 1, wherein when a plurality of separation membranes are configured in multiple stages, a permeate gas is supplied to one subsequent separation membrane. 4.   3. The laser gas recycling system according to claim 1, wherein when a plurality of separation membranes are configured in multiple stages, the non-permeating gas is supplied again to the previous separation membrane. 4.   3. The laser gas according to claim 1, wherein when a plurality of separation membranes are configured in multiple stages, the permeate gas emitted from the last-stage separation membrane is re-supplied to any one of the preceding separation membranes. Recycling system.   When multiple separation membranes are configured in multiple stages, at least the first booster, the separation membrane, the pressure regulator, and the second booster are unit units in the line from the separation membrane supply line to the permeate gas discharge line. The laser gas recycling system according to claim 1 or 2, wherein the plurality of units are connected in series in multiple stages.   Purifies high-purity neon gas by removing rare gases other than neon (krypton, argon, xenon) from exhaust gas discharged from excimer laser oscillators that use krypton-containing neon gas, argon / xenon-containing neon gas, or xenon-containing neon gas laser gas A separation membrane device having one or more separation membranes. Having one or more separation membranes for removing rare gases other than argon and neon from exhaust gas discharged from an excimer laser oscillation device using a laser gas of argon / xenon-containing neon gas, and purifying argon-containing high-purity neon gas, Separation membrane device.

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