JP2023535629A - Rare gas recovery system - Google Patents

Abstract

The system includes a pumping system (108, 208) configured to pump a respective exhaust gas from each of a plurality of chemical etching process chambers (106, 206) and combine the exhaust gases to provide a combined exhaust gas. ) and a noble gas recovery system (110, 210) configured to process the combined exhaust gas to remove one or more noble gases therein. [Selection drawing] Fig. 1

Description

The present invention relates to rare gas recovery systems.

Argon and xenon are known to be used in etching processes. Argon is a relatively common air gas, while xenon is relatively rare.
Systems are known for recovering noble gases such as xenon from dry etching processes. Such systems recover gas from a single etch chamber and return it to the same gas chamber in a closed loop system.

Etching processes utilizing krypton are currently under development. The viability of such processes may depend on the ability to recover krypton.
The inventors have recognized that the vacuum and abatement system can be used to simultaneously pump gas from multiple gas chambers using a common pump and optionally the abatement system.

We recover krypton from multiple gas chambers using a vacuum (and optionally abatement) system that simultaneously pumps gas from multiple gas chambers using a common pump, We recognize that this can improve efficiency and cost effectiveness.
The inventors have found that an open-loop system in which krypton is pumped into a collection vessel and stored at a given pressure until there is sufficient quantity to pass through the final purification process can improve efficiency and cost effectiveness. It has recognized.
The inventors recognize that closed loop systems may require redundancy at each stage. An open loop system can reduce such need.

In a first aspect, a pumping system configured to pump a respective exhaust gas from each of a plurality of chemical etching process chambers and combine the exhaust gases to provide a combined exhaust gas; and a noble gas recovery system configured to process and remove one or more noble gases (argon, xenon, or krypton, or any combination, mixture, admixture, etc. thereof) therefrom. be done.

In a further aspect, a system is provided that includes a noble gas supply, a plurality of process chambers, a pumping system, and a noble gas recovery system. Each process chamber operates in conjunction with other process chambers (e.g., concurrently, asynchronously, or in parallel) and receives a respective supply of one or more noble gases from a rare gas supply; or configured to perform an etching process using respective supplies of two or more noble gases and output respective exhaust gases. A pumping system is configured to pump respective exhaust gases from the plurality of process chambers, combine the exhaust gases to provide a combined exhaust gas, and pump the combined exhaust gases to the noble gas recovery system. there is The noble gas recovery system is configured to process the received combined exhaust gas to remove one or more noble gases therefrom.

Advantageously, the use of krypton or xenon in the process chamber helps achieve higher levels of precision and uniformity in high aspect ratio etch processes than is possible with low mass bombardment gases such as argon. .
Noble gases such as krypton and xenon occur naturally in air, but in low concentrations. The energy to separate a noble gas from air is approximately inversely proportional to the concentration of the separated gas. Due to the low concentration of krypton (or xenon) in air, the energy required to separate it from air is relatively high. Since krypton (or xenon) tends to be very concentrated in process exhaust (compared to air), the energy to separate it tends to be very low. Therefore, recovering krypton or xenon from the exhaust gas tends to reduce energy consumption. By recovering krypton or xenon from the combined exhaust gas, there is a tendency to secure the supply of krypton or xenon at low cost. Recovery processes tend not to rely on other gases with similarly high energy recovery costs or supply risks.

In some aspects, the pumping system can comprise a common pump configured to pump respective exhaust gases from multiple process chambers.
In some aspects, the pumping system can comprise a plurality of pumps (e.g., turbopumps), each pump of the plurality of pumps configured to pump exhaust gas from each of the plurality of process chambers. .

In some aspects, the noble gas recovery system can comprise a purification module configured to purify the combined exhaust gas. The purification module can be configured to remove gas from the combined exhaust gas using an absorber.
In some aspects, the noble gas recovery system can comprise a polishing module configured to perform a polishing process on the combined exhaust gas.

In some aspects, the noble gas recovery system can comprise a separation module configured to separate the noble gas from other components of the combined exhaust gas. The separation module can be configured to separate noble gases from various other gases in the combined exhaust gas using at least gas chromatography.

In any aspect, the rare gas recovery system includes a compression module configured to compress the separated one or more rare gases output by the separation module; and a storage module configured to store the noble gas. The storage module can be configured to output its contents in response to its contents reaching a threshold.

In any aspect, the noble gas recovery system can further comprise a distribution module configured to distribute one or more separated noble gases output by the separation module to multiple process chambers. The noble gas recovery system can further comprise multiple mixer boxes. each mixer box receives a respective first supply of one or more noble gases from the distribution module and a respective second supply of one or more noble gases from the further supply; Alternatively, the first and second supplies of one or more noble gases may be mixed and configured to supply the mixture to the respective process chambers.

In a further aspect, simultaneously supplying a respective supply of one or more noble gases from a noble gas supply to respective process chambers of a plurality of process chambers; Simultaneously performing etching processes with respective supplies of gases; simultaneously outputting respective exhaust gases by each process chamber; pumping respective exhaust gases from the plurality of process chambers by a pumping system; combining the exhaust gases by a pumping system to provide a combined exhaust gas; pumping the combined exhaust gas by the pumping system to a rare gas recovery system; and C. processing the received combined exhaust gas to remove one or more noble gases therefrom.

Processing can include separating one or more noble gases from other components of the combined exhaust gas by a separation module.

The method comprises compressing the separated one or more noble gases with a compression module; storing the compressed separated one or more noble gases with a storage module; withdrawing the contents of the storage module from the storage module in response to the contents of the storage module reaching a threshold level.

The method can further include distributing the separated one or more noble gases to a plurality of process chambers by a distribution module.

The combined exhaust gas can be combined, mixed, or blended with the purge gas.

A pumping system may be configured to receive the purge gas and combine the exhaust gas with the purge gas. The system can further comprise a vacuum pressure swing adsorption module configured to separate the purge gas from the combined exhaust gas. The purge gas can be nitrogen. A vacuum pressure swing adsorption module can be configured to supply the separated purge gas to the pumping system.

The noble gas recovery system can comprise a gas chromatographic separation module configured to separate one or more noble gases from other components of the combined exhaust gas using a gas chromatographic process. The gas chromatography separation module can be configured to receive a carrier gas used to transport the combined exhaust gas through the gas chromatography separation module. The noble gas recovery system can further comprise a separation module that separates one or more noble gases from the carrier gas. The gas chromatographic separation module can be configured to receive a carrier gas for use in transporting the combined exhaust gas through the gas chromatographic separation module. The noble gas recovery system can further comprise additional separation modules for separating other components of the combined exhaust gas from the carrier gas. The carrier gas can be reused/recycled by the gas chromatography separation module.

The carrier gas used preferably has different properties than the recovered gas (ie krypton or xenon) so that the separation step can distinguish it. Preferably, the carrier gas is inert or at least non-reactive with any other gas in the process. The purpose of the claimed system is to recover high molecular weight noble gases such as krypton or xenon. Therefore, the carrier gas should preferably be a light, inert gas. Preferably, the carrier gas is helium.

Etch processes may include helium and may be able to accommodate helium introduced with krypton or xenon, but this may introduce variability risks and reliance on uncontrolled flow. . This can lead to unacceptable variations in the etching process. Preferably, precise process control is provided in high aspect ratio etching processes in which krypton or xenon are introduced. This helps improve process consistency (wafer-to-wafer and across-wafer uniformity).

Helium is not air gas. Procurement of helium tends to be expensive and requires a great deal of energy. Additionally, the supply of helium for use in the semiconductor industry can be erratic. Energy consumption can be reduced by reusing/reusing the helium carrier gas. Additionally, the helium supply can be made more reliable, which helps improve the consistency of the etching process and reduce variability.

The noble gas recovery system can comprise an acid gas removal module configured to remove acid gases from the combined exhaust gas.
The rare gas recovery system includes a wet scrubber configured to perform a scrubbing process on combined exhaust gases. The noble gas recovery system can comprise a dryer configured to perform a drying process on the gas stream output from the wet scrubber.

A pump system includes a plurality of pumps, each configured to pump exhaust gas from each of the plurality of process chambers, and removes perfluorinated compounds (PFCs) from the gas stream output by the plurality of pumps. or a plurality of perfluorinated compound (PFC) removal or conversion modules configured to convert PFCs to other compounds, each of the plurality of PFC removal or conversion modules being connected to a plurality of pumps connected to each of the One or more of the PFC removal or conversion modules may comprise combustors, plasma reactors, composite plasma catalyst (CPC) modules, and/or abatement devices.

Preferably, the PFC removal or conversion module comprises a plasma reactor or a module using plasma.

The plasma converts the PFCs into gases that can be dissolved in a suitable dose of water (process water). The plasma by-products can then be continuously removed from the system, for example, by a wet scrubber, and can be discharged, for example, to the acid exhaust and drainage system of equipment typically found in the etch section of a semiconductor manufacturing plant. Advantageously, wet scrubbers are not bulky and tend not to add additional load to acid discharge and waste water.

Therefore, PFCs and pyrogenic gases tend to be destroyed before entering the vacuum pump module. This advantageously means less nitrogen purging, which may be used in pumps for flammability protection purposes, for example. Reducing the amount of additional nitrogen purge gas used tends to avoid the removal of nitrogen purge gas which would complicate the system and increase its footprint and cost of ownership.

Advantageously, a wet scrubber (which may be a dose wet scrubber) can remove foreline plasma byproducts by acid exhaust. Noble gases are passed through a gas chromatographic separation module, after which krypton or xenon can be polished. This will allow the minimization of a pressure swing absorption (PSA) unit that can effectively separate noble gases and/or other contaminants from krypton or xenon prior to passing the gas through a gas chromatography column. help. PSA helps clean up at pressures above atmospheric pressure (about 5 psi), which means lower operating energy or cost requirements.

Advantageously, using a plasma reactor and wet scrubber to remove PFCs and exothermic gases tends to reduce the overall system footprint. For example, an etch process within the process chamber may use krypton at the same time as the PFC. Even if there are times in the process when only krypton flows, if the system is recovering krypton from multiple asynchronous chambers, the system allows krypton and PFC to flow together. The plasma can be used to react the PFCs in a wet scrubber into water soluble products so that they can be removed from the system. Alternatively, an absorber placed in the vacuum foreline or atmospheric pressure line can be used. If the absorber is installed in the vacuum foreline, it needs to be very large to ensure that it does not introduce unacceptable restrictions that would prevent the process pressure from being achieved within the process chamber. be. Therefore, the footprint will be large. On the other hand, the absorber installed after the pump would need to be sized for the additional diluent gas used to protect the pump from corrosion by PFCs. Therefore, the atmospheric pressure absorber must be sized for the flow rate and must be replaced frequently, resulting in both space cost and parts cost.

A noble gas recovery system can comprise a getter module that includes a getter. The getter can be titanium.

A pumping system may be configured to receive the purge gas and combine exhaust gas with the purge gas, and a noble gas recovery system is connected to the pumping system to remove acid gases from the combined exhaust gas received from the pumping system. a vacuum pressure swing adsorption module configured to receive a gas stream from the acid gas removal module and separate a purge gas from the received gas stream; and a gas stream from the vacuum pressure swing adsorption module. receiving and using a gas chromatography process to separate one or more noble gases from other components of the gas stream received from the vacuum pressure swing adsorption module and outputting the separated one or more noble gases. a gas chromatographic separation module configured to:

A pumping system includes a plurality of pumps, each configured to pump exhaust gas from each of the plurality of process chambers, and removes perfluorinated compounds (PFCs) from the gas stream output by the plurality of pumps. or a plurality of perfluorinated compound (PFC) removal or conversion modules configured to convert PFCs to other compounds, each of the plurality of PFC removal or conversion modules being connected to a plurality of pumps. A wet scrubber configured to perform a scrubbing process on the combined exhaust gas and, optionally, a drying process on the gas stream output from the wet scrubber, respectively connected to the noble gas recovery system. and a dryer configured to. A noble gas recovery system receives a gas stream from a wet scrubber or dryer and uses a gas chromatography process to separate one or more noble gases from other components of the gas stream received from the wet scrubber or dryer. and a gas chromatography separation module configured to output the separated one or more noble gases. Each of the plurality of PFC removal or conversion modules can comprise a plasma, eg, a plasma reactor.

The pump system may be configured to receive the purge gas and the additional purge gas and combine the exhaust gas with the purge gas and the additional purge gas, and the noble gas recovery system receives the gas stream from the pumping system and from the received gas stream A vacuum pressure swing adsorption module configured to separate a purge gas and a getter configured to receive a gas stream from the vacuum pressure swing adsorption module and remove gas from the gas stream received from the vacuum pressure swing adsorption module. a getter module for receiving the gas stream from the getter module, separating one or more noble gases in the received gas stream from additional purge gas in the received gas stream, and separating one or more noble gases in the received gas stream; a separation module configured to output a

1 is a schematic diagram of a microfabrication system and an open loop noble gas recovery system (not to scale); FIG. 1 is a schematic diagram of a microfabrication system and a closed-loop noble gas recovery system (not to scale); FIG. FIG. 4 is a schematic diagram (not to scale) showing further details of a portion of the microfabrication system; FIG. 4 is a schematic diagram (not to scale) showing further details of a portion of a further microfabrication system; FIG. 4 is a schematic diagram (not to scale) showing further details of a portion of yet another microfabrication system;

FIG. 1 is a schematic diagram (not to scale) of a microfabrication system 100 and an open-loop exhaust gas treatment system 102 according to one embodiment.
Microfabrication system 100 comprises a krypton supply 104 and a plurality of process chambers 106 .
The krypton supply 104 is configured to supply krypton gas to each of the plurality of process chambers 106 .

Each of the process chambers 106 is configured to use the received krypton gas to perform an etching process that chemically removes a layer from the surface of the wafer located therein.
Exhaust gas treatment system 102 is operatively coupled to microfabrication system 100 . Exhaust gas treatment system 102 is configured to recover krypton used for etching by microfabrication system 100 .

The exhaust gas treatment system 102 includes a pumping system 108 and a krypton recovery system 110 .
Pumping system 108 is configured to pump (eg, at about atmospheric pressure) exhaust gases from multiple process chambers 106 to krypton recovery system 110 .
Pumping system 108 includes a plurality of turbopumps 112 and a pumping module 114 .

Each turbopump 112 is connected to a respective process chamber 106 . Each turbopump 112 is configured to pump exhaust gases from the process chamber 106 connected to the pumping module 114 .

Pumping module 114 includes a pump. Pumping module 114 is configured to pump exhaust gas from turbo pump 112 to krypton recovery system 110 . In operation, pumping modules 114 receive respective exhaust gas streams from turbopumps 112 . Pumping module 114 combines each received exhaust gas stream into a combined gas stream. Pumping module 114 pumps the combined gas stream to krypton recovery system 110 .

In some embodiments, pumping module 114 is further configured to receive (eg, pump) additional gas that is a purge gas. The pumping module 114 may be configured to mix or blend the pumped exhaust gas with the pumped purge gas. This exhaust gas and purge gas mixture or admixture can then be pumped to the krypton recovery system 110 . Advantageously, the addition of this purge gas helps extend the operational life of the pumping module 114 .

Purge gas amounts and compositions are application dependent and can be selected based on system requirements and/or operation. The amount and composition of the purge gas can be selected to facilitate downstream separation of one or more noble gases (ie krypton in this embodiment) from other components of the gas mixture. In some embodiments, it may be advantageous for the purge gas to be specifically selected such that it is easy to separate from krypton by one or another means in the separation module 120 of the krypton recovery system 110. be. In some embodiments, the purge gas can become wholly or partially from gases that would otherwise be excluded from separation module 120 after being separated from krypton. This tends to have the effect of simplifying the separation process. In addition, this increases overall efficiency and reduces system maintenance costs as additional gas can be reused where it would normally be consumed within the separation module and recirculated via the pump purge. help to do

Krypton recovery system 110 includes control module 116 , purification module 118 , separation module 120 , polishing module 122 , compression module 124 and storage module 126 .
Control module 116 is configured to control the operation of the other modules of krypton recovery system 110 . That is, control module 116 controls the operation of purification module 118 , separation module 120 , polishing module 122 , compaction module 124 , and storage module 126 .

Purification module 118 is configured to receive the combined gas flow from pumping module 114 . Purification module 118 is configured to purify the received combined gas stream, thereby providing a purified gas stream. The purification module 118 removes toxic and corrosive gases from the combined gas stream by promoting a chemical or physical reaction between the specified gas and one or more solid materials, e.g., at ambient or elevated temperature. can be configured to remove In some embodiments, an absorber can be implemented. Purification module 118 is configured to supply a purge gas stream to separation module 120 .

Separation module 120 is configured to receive the purge gas stream from purification module 118 . Separation module 120 is configured to separate krypton from other components of the purified gas stream, thereby providing a gas stream comprising separated krypton. Separation module 120 can be configured to separate the large, heavy, and therefore slow krypton molecules from the lighter inert gases using gas chromatography. Separation module 120 is configured to supply separated krypton to polishing module 122 .

Polishing module 122 is configured to receive the separated krypton from separation module 120 . Polishing module 122 is configured to perform a polishing process on the separated krypton-containing gas stream, thereby providing a polished gas stream. The term "polishing" can be understood to refer to the removal of trace contaminants, excluding noble gases. The polishing process can be carried out using chemical means or physical means, more preferably a combination of chemical and physical means. Polishing module 122 is configured to provide a polishing gas stream to compression module 124 .

In some embodiments, polishing module 122 is omitted from the open loop system of FIG. In such embodiments, polishing can be performed at a later stage, for example, on the contents removed from storage module 126, for example, at a location remote from system 100 or at another facility. can be done.

In this embodiment, polishing module 122 is connected between separation module 120 and compression module 124 . However, in other embodiments, polishing modules 122 are connected between different module sets. For example, in some embodiments, polishing module 122 is connected between compression module 124 and storage module 126 rather than between separation module 120 and compression module 124 . In such other embodiments, polishing module 122 is arranged to perform a polishing process on the stream of compressed gas received from compression module 124 and output the polished compressed gas to storage module 126 .

Compression module 124 comprises a compressor. In this embodiment, compression module 124 is configured to receive the polishing gas flow from polishing module 122 . Compression module 124 is configured to compress the polishing gas stream, thereby providing a compressed gas stream. A compressed gas stream has a high pressure, ie, a pressure greater than atmospheric pressure. The pressure of the compressed gas stream can depend on the application and can be selected such that a threshold amount of gas can be stored in a given volume. Compression module 124 is configured to supply a stream of compressed gas to storage module 126 .

Storage module 126 is configured to receive the compressed gas stream from compression module 124 . Storage module 126 is configured to store the received compressed gas.
Storage module 126 may continue to receive and store krypton-containing gas until the amount of gas and/or krypton stored therein reaches a threshold level. When the amount of gas and/or krypton stored in storage module 126 reaches a threshold level, a further (eg, final) purification process can be performed on the stored gas to recover the krypton therein. Krypton stored in the storage module can be returned to the krypton supply 104 or used for another purpose (eg, after performing further purification processes in some embodiments).
Accordingly, a microfabrication system 100 and an open loop exhaust gas treatment system 102 are provided.

FIG. 2 is a schematic diagram (not to scale) of a microfabrication system 200 and a closed loop exhaust gas treatment system 202 according to one embodiment.
The microfabrication system 200 comprises a krypton supply 204 , multiple mixer boxes 205 and multiple process chambers 206 .

The krypton supply 204 is configured to supply krypton gas to each of the plurality of mixer boxes 205 .
Each of mixer boxes 205 is configured to receive a respective supply of krypton from krypton supply 204 . Each of mixer boxes 205 is further configured to receive a respective supply of krypton from distribution module 228 of exhaust gas treatment system 202, the function of which will be described in more detail below. Each of mixer boxes 205 is further configured to blend or mix krypton received from krypton supply 204 and distribution module 228 to form a respective mixed supply of krypton.

Each mixer box 205 is connected to a respective process chamber 206 . Each of mixer boxes 205 is further configured to supply a respective mixed feed of krypton to a respective process chamber 206 to which it is connected. The mixing or blending performed by each mixer box 205 may be such that each process chamber 206 is supplied with the desired or required amount of krypton. The mixing or blending performed by each mixer box 205 may reduce the purity of the gas delivered to the process chamber 206, for example, where the krypton from the supply 204 and distribution module 228 may have different levels of trace impurities. can be performed to adjust.

Each of the process chambers 206 is configured to use the received krypton gas to perform an etching process that chemically removes a layer from the surface of the wafer located therein.
Exhaust gas treatment system 202 is operatively coupled to microfabrication system 200 . Exhaust gas treatment system 202 is configured to recover krypton used for etching by microfabrication system 200 .

Exhaust gas treatment system 202 includes a pumping system 208 and a krypton recovery system 210 .
Pumping system 208 is configured to pump (eg, at about atmospheric pressure) exhaust gases from multiple process chambers 206 to krypton recovery system 210 .
Pumping system 208 includes a plurality of turbopumps 212 and a pumping module 214 .

Each turbopump 212 is connected to a respective process chamber 206 . Each turbopump 212 is configured to pump exhaust gases from the process chamber 206 connected to the pumping module 214 .

Pumping module 214 comprises a pump. Pumping module 214 is configured to pump exhaust gas from turbo pump 212 to krypton recovery system 210 . In operation, pumping modules 214 receive respective exhaust gas streams from turbopumps 212 . Pumping module 214 combines the received exhaust gas streams into a combined gas stream. Pumping module 214 pumps the combined gas stream to krypton recovery system 210 .

In some embodiments, pumping module 214 is further configured to receive (eg, pump) additional gas that is a purge gas. Pumping module 214 may be configured to mix or blend the pumped exhaust gas with the pumped purge gas. This exhaust gas and purge gas mixture or admixture can then be pumped to the krypton recovery system 210 . Advantageously, the addition of this purge gas helps extend the operational life of the pumping module 214 .

As with other embodiments, the purge gas amount and composition are application dependent and can be selected based on system requirements and/or operation. Purge gas amount and composition can be selected to facilitate downstream separation of krypton from other components of the gas mixture. In some embodiments, it may be advantageous for the purge gas to be specifically selected such that it is easy to separate from krypton by one or other means in the separation module 220 of the krypton recovery system 210. be. In some embodiments, the purge gas can become wholly or partially from gases that would otherwise be excluded from separation module 220 after being separated from krypton. This tends to have the effect of simplifying the separation process. In addition, this increases overall efficiency and reduces system maintenance costs as additional gas can be reused where it would normally be consumed within the separation module and recirculated via the pump purge. help to do

Krypton recovery system 210 comprises control module 216 , purification module 218 , separation module 220 , polishing module 222 , storage module 226 and distribution module 228 .
Control module 216 is configured to control the operation of the other modules of krypton recovery system 210 . That is, control module 216 controls the operation of purification module 218 , separation module 220 , polishing module 222 , storage module 226 and distribution module 228 .

Purification module 218 is configured to receive the combined gas flow from pumping module 214 . Purification module 218 is configured to purify the received combined gas stream, thereby providing a purified gas stream. Purification module 218 may be configured to remove toxic and corrosive gases from the combined gas stream using absorbers such as GRC columns. Purification module 218 is configured to supply a purge gas stream to separation module 220 . In this closed-loop system, purification module 218 advantageously helps keep unwanted contaminants from being returned to process chamber 206 .

Separation module 220 is configured to receive the purge gas stream from purification module 218 . Separation module 220 is configured to separate krypton from other components of the purge gas stream, thereby providing a gas stream comprising separated krypton. Separation module 220 can be configured to separate the large, heavy, and therefore slow krypton molecules from the lighter inert gases using gas chromatography. Separation module 220 is configured to provide a gas stream of separated krypton to polishing module 222 .

Polishing module 222 is configured to receive the separated krypton from separation module 220 . Polishing module 222 is configured to perform a polishing process on the separated krypton, thereby providing a polished gas stream. Polishing module 222 is configured to provide a polishing gas stream to storage module 226 .

In this embodiment, polishing module 222 is connected between separation module 220 and storage module 226 . However, in other embodiments, polishing modules 222 are connected between different module sets. For example, in some embodiments the closed loop system comprises a compression module (such as described in more detail above with reference to FIG. 1). A polishing module 222 may be placed after the compression module. Polishing module 222 is arranged to perform a polishing process on the stream of compressed gas received from the compression module and output the polished compressed gas to storage module 226 . In some embodiments, polishing module 222 is connected to a compression module downstream from polishing module 222, and polishing module 222 outputs a polishing gas flow to the compression module.
In some embodiments, polishing module 222 is omitted from the closed loop system of FIG.

Storage module 226 is configured to receive the polishing gas flow from polishing module 222 . Storage module 226 is configured to store the received polishing gas. Storage module 226 is configured to supply stored krypton-containing gas to distribution module 228 . In some embodiments, this storage module 226 can be omitted.

Distribution module 228 is configured to receive the krypton-containing gas from storage module 226 . Distribution module 228 is configured to distribute the received krypton-containing gas between each mixer box 205 connected thereto. Distribution module 228 is configured to split or separate the krypton-containing gas stream received from storage module 226 into a plurality of separate gas streams and supply each of the separate gas streams to a respective mixer box 205 . ing. Krypton is thus recovered and reused.

The advantage provided by the system described above is that the cost and physical footprint of the krypton recovery system is shared across multiple processing chambers, thereby increasing efficiency (e.g., in terms of physical size) per processing chamber. That is.
In the above embodiments, the pumps of the pumping modules 114,214 can be considered common pumps, ie, pumps common to all of the processing chambers 106,208.

Further details of a krypton recovery system that may be implemented with the open-loop exhaust gas treatment system 102 described in more detail above with respect to FIG. 1 and/or the closed-loop exhaust gas treatment system 202 described in more detail above with respect to FIG. Description will be made below with reference to FIGS.

FIG. 3 is a schematic diagram (not to scale) showing further details of a portion of microfabrication system 300 .
The portion of microfabrication system 300 shown in FIG. 3 includes process chamber 306 , turbo pump 312 , pumping module 314 and krypton recovery system 310 .

The process chamber 306 can be the same as or similar to one or more of the process chambers 106, 206 described in more detail above with reference to FIGS. Although only a single process chamber 306 is shown in FIG. 3, it should be understood that, in practice, multiple process chambers 306 are present in this embodiment.

Turbopump 312 may be the same or similar to one or more of turbopumps 112, 212 described in more detail above with reference to FIGS. Although only a single turbopump 312 is shown in FIG. 3, it should be understood that, in practice, multiple turbopumps 312 are present in this embodiment. Each turbopump 312 is connected to a respective process chamber 306 and configured to pump exhaust gases from the respective process chamber 306 .

Pumping module 314 may be the same as or similar to one or both of pumping modules 114, 214 described in more detail above with reference to FIGS. Pumping module 314 includes a pump, which may be a dry pump. Pumping module 314 is configured to direct the exhaust gas from each of turbopumps 312 to krypton recovery system 310 via manifold 330 . Pumping module 314 combines the received exhaust gas streams into a combined gas stream and pumps the combined gas stream to krypton recovery system 310 .

In this embodiment, the pumping module 314 is further configured to receive (eg, pump) the purge gas. The flow of purge gas to pumping module 314 and/or manifold is indicated by arrows and reference numeral 340 in FIG. Pumping module 314 is configured to mix or blend the pumped exhaust gas with the pumped purge gas. This exhaust gas and purge gas mixture or admixture is then pumped to the krypton recovery system 310 . Advantageously, the addition of this purge gas helps extend the operational life of the pumping module 314 .
In this embodiment, the purge gas is nitrogen.

Purge gas amounts and compositions are application dependent and can be selected based on system requirements and/or operation. The amount and composition of the purge gas can be selected to facilitate downstream separation of one or more noble gases (ie krypton in this embodiment) from other components of the gas mixture.

In this embodiment, the krypton recovery system 310 includes an acid gas removal module 350, a first compressor 352, a vacuum pressure swing adsorption (VPSA) module 354, a second compressor 355, a plurality of first storage modules 356, It comprises a gas chromatography module 358 , a separation module 360 , a carrier gas supply 364 , a thermal conductivity detector (TCD) 366 , a third compressor 368 , a purification module 370 and a krypton storage module 326 .

Acid gas removal module 350 is connected to pumping module 314 . Acid gas removal module 350 is configured to receive the combined gas stream from pumping module 314 . Acid gas removal module 350 is configured to remove toxic, corrosive and/or acidic compounds, such as toxic, corrosive and/or acidic gases, from the received combined gas stream. The acid gas removal module 350 can be a gas reactor column (GRC). Acid gas removal module 350 is configured to supply the gas stream (after removal of toxic, corrosive and/or acid compounds) to first compressor 352 .

First compressor 352 is configured to receive the gas stream output by acid gas removal module 350 . First compressor 352 is configured to compress the received gas stream, thereby providing a compressed gas stream. First compressor 352 is configured to provide a compressed gas stream to VPSA module 354 .

VPSA module 354 is configured to receive the compressed gas flow from first compressor 352 . VPSA module 354 is configured to separate the purge gas (and optionally other gas species) from the gas mixture in the compressed gas stream. The VPSA module 354 separates gases under pressure due to the molecular properties of the chemical species and their affinity for the adsorbents used in the VPSA module 354 . Preferably, the VPSA module 354 separates the maximum amount of purge gas, ie nitrogen in this embodiment, from the compressed gas stream. In practice, the VPSA module 354 can, for example, remove/separate approximately 95% of the nitrogen present in the compressed gas stream.

The VPSA module 354 is connected to the pump module 314 such that the separated purge gas is returned to the pump module 314 for the purge process, ie the nitrogen purge gas is reused or recycled.
The VPSA module 354 is connected to a second compressor 355 such that other gas species separated by the VPSA module 354 (i.e., gases other than the nitrogen purge gas) are sent to the second compressor 355. .

A second compressor 355 is configured to receive the gas flow output by the VPSA module 354 . The second compressor 355 is configured to compress the received gas stream thereby providing a compressed gas stream. Second compressor 355 is configured to supply a stream of compressed gas to first storage module 356 .

A second compressor 355 is connected to the first storage module 356 via a first valve 380 . The first valve 380 is a two-way valve. The first valve 380 is configured to control gas flow between the second compressor 355 and the first storage module 356 (e.g., as described in detail above with reference to FIGS. 1 and 2). (by a control module, such as control module 116 or control module 216).

First storage module 356 is configured to receive and store gas from VPSA module 354 . The gas stream received by the first storage module 356 may be a compressed stream, ie under pressure. Accordingly, in this embodiment, the first storage module 356 receives and stores a gas stream from which at least a portion of the toxic, corrosive and/or acidic compounds and at least a portion of the purge gas have been removed.

Each first storage module 356 is connected to a gas chromatography module 358 such that gases stored in the first storage modules 356 can be supplied to the gas chromatography module 358 .
Each first storage module 356 is connected to gas chromatography module 358 via a second valve 382 . The second valve 382 is a three-way valve. A second valve 382 is provided to control gas flow between the first storage module 356 and the gas chromatography module 358 (e.g., the control valve described in detail above with reference to FIGS. 1 and 2). module 116 or a control module, such as control module 216).

Gas chromatography module 358 is configured to receive the gas stream from first storage module 356 at its inlet. Gas chromatography module 358 may consist of a gas chromatography column. Although only one gas chromatography module 358 (ie, gas chromatography column) is shown in FIG. 3, it should be understood that, in practice, multiple gas chromatography modules/columns 358 may be present. Multiple gas chromatography modules/columns 358 can be arranged to operate in parallel or in series.

Gas chromatography module 358 is configured to separate krypton from other components of the received gas stream using gas chromatography. In this embodiment, during operation, the lighter gas exits the gas chromatography module 358 first, and then (i.e., at a later point in time) the heavier gas (i.e., krypton in this embodiment) exits the gas chromatography module 358. get out.

In this embodiment, the inlet of gas chromatography module 358 is connected to carrier gas supply 364 such that gas chromatography module 358 receives carrier gas from carrier gas supply 364 . In this embodiment, the carrier gas is helium. A carrier gas is used by gas chromatography module 358 to help separate krypton from other gas species in the received gas stream. Specifically, a carrier gas is used to transport or carry the received gas stream through gas chromatography module 358 .

Gas chromatography module 358 is connected to carrier gas supply 364 via third valve 384 and fourth valve 386 . Third valve 384 is a two-way valve. A third valve 384 is provided to control the flow of carrier gas between the carrier gas supply 364 and the gas chromatography module 358 (e.g., the control valve described in detail above with reference to FIGS. 1 and 2). module 116 or a control module, such as control module 216). The fourth valve 386 is a check valve.
Gas chromatography module 358 is connected at its outlet to TCD 366 .

The TCD 366 is configured to sense changes in the thermal conductivity of gases exiting the gas chromatography module 358 to detect when a different chemical species gas (eg, krypton) is being output. The TCD 366 can compare the gas exiting the gas chromatography module 358 to pure helium over time and can be calibrated to detect when krypton exits the gas chromatography module 358 .

The outlet of chromatography module 358 is connected to carrier gas supply 364 , system outlet 367 and separation module 360 via TCD 366 .
The outlet of chromatography module 358 is connected to carrier gas supply 364 via fifth valve 388 . Fifth valve 388 is a two-way valve. Fifth valve 388 is used to control the flow of gas output by gas chromatography module 358 to carrier gas supply 364 (for example, the control module described in detail above with reference to FIGS. 1 and 2). 116 or by a control module such as control module 216).

The output of chromatography module 358 is connected to system outlet 367 via sixth valve 390 . The sixth valve 390 is a two-way valve. A sixth valve 390 is provided to control the flow of gas output by the gas chromatography module 358 to the system outlet 367 (eg, the control module 116 described in detail above with reference to FIGS. 1 and 2). or by a control module, such as control module 216).

The output of chromatography module 358 is connected to separation module 360 via seventh and eighth valves 391,392. The seventh valve 391 is a three-way valve. Eighth valve 392 is a two-way valve. Each of the seventh and eighth valves 391, 392 are configured to control the flow of gas output by the gas chromatography module 358 to the separation module 360 (e.g., as detailed above with reference to FIGS. 1 and 2). (by a control module such as control module 116 or control module 216 described in ).

In this embodiment, valves 388, 390, 391, 392 are controlled in response to TCD 366 detecting helium (i.e., carrier gas) output from gas chromatography module 358 to output Gas (ie, helium) is delivered to carrier gas supply 364 . Therefore, the helium carrier gas can be reused/recycled.

Also, in response to the TCD 366 detecting a waste gas (e.g., which may be heavier than helium and lighter than krypton) being output from the gas chromatography module 358, the valves 388, 390, 391, 392 enable the chromatographic Gas output from module 358 (ie waste gas mixed with helium) is controlled to be sent to system outlet 367 . These waste gases can be detoxified and discarded. Waste gases can include, but are not limited to, argon, nitrogen, and/or oxygen gases that may be mixed with helium carrier gas.

Also, in response to TCD 366 detecting krypton being output from gas chromatography module 358 , valves 388 , 390 , 391 , 392 cause the output gas (i.e., mixed with helium) output from chromatography module 358 to krypton) to the first separation module 360 .

In other embodiments, different valve arrangements than shown in FIG. 3 can be implemented to route the gas exiting the gas chromatography module 358 . Also, in other embodiments, instead of or in addition to the TCD 366, different techniques for detecting which chemical species of gas are present in the output gas may be implemented.

In operation, separation module 360 receives a gas stream containing a mixture of krypton and helium carrier gases from gas chromatography module 358 . Separation module 360 is configured to process this gas stream to separate krypton from the helium carrier gas. Separation module 360 may use any suitable gas separation technology. For example, separation module 360 can comprise a membrane, filter, metal-organic framework (MOF), or gas chromatography separation module to separate krypton from a helium carrier gas.

Separation module 360 is further configured to output separated krypton, for example, to krypton storage module 326 as shown in FIG. 3 or to distribution module 228 as shown in FIG. 2 and described in detail above. there is Krypton storage module 326 may be similar or identical to storage module 126 described in detail above with reference to FIG. In this embodiment, the separation module 360 is connected to the krypton storage module 326 via a third compressor 368 and a purification module 370 that respectively compress and purify the krypton before it is stored in the krypton storage module 326 . In some embodiments, third compressor 368 and/or purification module 370 are omitted.

Purification module 370 is configured to receive krypton output by separation module 360 . Purification module 370 is configured to purify received krypton. Any suitable purification process may be performed, such as pressure swing adsorption purification or cryogenic purification.

The separation module 360 is further configured to output separated helium carrier gas and send the helium carrier gas back to the second compressor 355, thereby reusing/recycling the helium. A ninth valve 394 may regulate the flow of helium from the separation module 360 back to the second compressor 355 . The ninth valve 394 is a two-way valve. Ninth valve 394 is configured to be controlled (eg, by a control module such as control module 116 or control module 216 described in detail above with reference to FIGS. 1 and 2).

In some embodiments, separation module 360 is further configured to output separated helium carrier gas and to send the helium carrier gas back to carrier gas supply 364 .
Accordingly, one embodiment of a krypton recovery system is provided.

FIG. 4 is a schematic diagram (not to scale) showing further details of a portion of microfabrication system 400 .
Elements in common with the embodiments shown in FIGS. 3 and 4 are indicated using the same reference numerals.
The portion of microfabrication system 400 shown in FIG.
Process chamber 306, turbo pump 312, manifold 330, and pumping module 314 are as described in more detail above with reference to FIG. 3 and are not described again below for the sake of brevity.

In this embodiment, part of the microfabrication system 400 further comprises a plurality of perfluorinated compound (PFC) removal or conversion modules (hereinafter "PFC removal modules" 402). Each PFC removal module 402 is connected between a respective turbopump 312 and manifold 330 .
PFC removal module 402 is configured to remove or convert PFCs to other compounds from the gas stream output by turbopump 312 . PFC removal module 402 may implement any suitable PFC removal process. PFC removal modules 402 may include, but are not limited to, combustors, plasma reactors, composite plasma catalyst (CPC) modules, abatement modules, and the like.

In some embodiments, krypton recovery system 410 can be identical to krypton recovery system 310 shown in FIG. 3 and described in more detail above. In some embodiments, krypton recovery system 410 can be identical to krypton recovery system 310 except that the acid gas removal module is replaced with a wet scrubber (as described below). In some embodiments, krypton recovery system 410 may be identical to krypton recovery system 310 except that VPSA module 354 is omitted. In some embodiments, the krypton recovery system 410 is the same as the krypton recovery system 310 except that the acid gas removal module is replaced with a wet scrubber (as described below) and the VPSA module 354 is omitted. can be the same.

In this embodiment, krypton recovery system 410 includes scrubber 420, first compressor 352, first storage module 356, gas chromatography module 358, separation module 360, additional separation module 460, carrier gas supply 364, It comprises a second storage module 466 , a fourth compressor 468 and (optionally) a purification module 370 . The krypton recovery system 410 includes a first valve 380, a second valve 382, a tenth valve 484, an eleventh valve 486, a twelfth valve 488, a thirteenth valve 490, a fourteenth valve 492, and a Further includes fifteen valves 494 . First compressor 352, first storage module 356, gas chromatography module 358, separation module 360, carrier gas supply 364, and valves 380-382 are described in more detail above with reference to FIG. and will not be described again below for the sake of brevity.

A scrubber 420 is connected to the pumping module 314 . Scrubber 420 is configured to receive the combined gas flow from pumping module 314 . The scrubber 420 is configured to remove certain substances (eg, toxic, corrosive and/or acidic compounds or gases) from the gas stream flowing therethrough. In this embodiment, scrubber 420 is a wet scrubber configured to introduce a cleaning liquid, such as water, into the gas stream flowing through scrubber 420 . For example, the scrubber 420 may spray the gas stream with a cleaning liquid, pass the gas stream through a reservoir of cleaning liquid, or perform some other contact method. In this embodiment, scrubber 420 receives a supply of cleaning liquid, for example water, and outputs used cleaning liquid, as indicated by arrow and reference numeral 424 in FIG.

Preferably, a dryer is connected to the outlet of scrubber 420 to dry the gas stream output by scrubber 420 (ie, remove liquids and/or vapors).
Scrubber 420 is configured to supply the scrubbed/cleaned gas stream to first compressor 352 .

Gas chromatography module 358 is connected to carrier gas supply 364 via first valve 486 , second storage module 466 , tenth valve 484 , and second valve 382 . The tenth valve 484 is a four-way valve. Eleventh valve 486 is a two-way valve. The tenth and eleventh valves 484, 486 are configured to be controlled (eg, by a control module such as control module 116 or control module 216 described in detail above with reference to FIGS. 1 and 2). there is Eleventh valve 486 is controlled to control the flow of carrier gas between carrier gas supply 364 and second storage module 466 . Second storage module 466 is configured to receive and store carrier gas from carrier gas supply 364 . Second storage module 466 is configured to supply carrier gas to gas chromatography module 358 for use in the gas chromatography separation process. The second and tenth valves 382 , 484 can be controlled to regulate the supply of carrier gas to the gas chromatography module 358 .

Gas chromatography module 358 is connected to separation module 360 and additional separation module 460 .
The output of chromatography module 358 is connected to additional separation module 460 via a twelfth valve 488 . The twelfth valve 488 is a two-way valve. A twelfth valve 488 is used to control the flow of gas output by the gas chromatography module 358 to the additional separation module 460 (for example, the control described in detail above with reference to FIGS. 1 and 2). module 116 or a control module, such as control module 216).

The output of chromatography module 358 is also connected to separation module 360 via a thirteenth valve 490 . The thirteenth valve 490 is a two-way valve. A thirteenth valve 490 is used to control the flow of gas output by the gas chromatography module 358 to the separation module 360 (for example, the control module 116 or (by a control module, such as control module 216).

In this embodiment, valves 488 and 490 allow the relatively light gas (mixed with the helium carrier gas) exiting gas chromatography module 358 to be sent to additional separation module 460, while the relatively Heavy gas, krypton (mixed with helium carrier gas) is controlled to be sent to separation module 360 . Any suitable process can be used to detect when krypton exits the gas chromatography module 358 and control the valves 488, 490 to properly route the output gas. For example, a TCD can be implemented in a manner similar to that described above with reference to FIG.

In operation, additional separation module 460 extracts from gas chromatography module 358 a gas stream comprising a mixture of relatively light gases (eg, which may include argon, nitrogen, and/or oxygen gas) and helium carrier gas. receive. An additional separation module 460 is configured to process this gas stream to separate the lighter gases from the helium carrier gas. Additional separation module 460 may use any suitable gas separation technology.

Additional separation module 460 is further configured to output separated lighter gases from system 400 . These gases can be output to an abatement system.
Additional separation module 460 is further configured to output separated helium carrier gas and send the helium carrier gas back to second storage module 466 where it is stored for subsequent reuse/reuse. In this embodiment, additional separation module 460 is connected to second storage module 466 via a fourth compressor 468 that compresses helium before it is stored in second storage module 466 .

In operation, separation module 360 receives a gas stream comprising a mixture of krypton and helium carrier gases from gas chromatography module 358 . Separation module 360 is configured to process this gas stream to separate krypton from the helium carrier gas. Separation module 360 may use any suitable gas separation technology. For example, separation module 360 may comprise a membrane, filter, or metal-organic framework (MOF) to separate krypton from the helium carrier gas.

Separation module 360 is further configured to output separated krypton, for example, to krypton storage module 326 as shown in FIG. 4 or to distribution module 228 as shown in FIG. 2 and described in more detail above. there is Krypton storage module 326 may be similar or identical to storage module 126 described in detail above with reference to FIG.

The separation module 360 is further configured to output separated helium carrier gas and send the helium carrier gas back to the second storage module 366 for storage there for subsequent reuse/recycle. In this embodiment, separation module 360 is connected to second storage module 366 via a fourth compressor 468 that compresses helium before it is stored in second storage module 366 .

Optionally, in this embodiment, the input and output of gas chromatography module 358 are connected via conduits and fourteenth valve 492 . The fourteenth valve 492 is a two-way valve. Fourteenth valve 492 is configured to control the flow of gas output by gas chromatography module 358 back to the input to gas chromatography module 358 (e.g., as described above with reference to FIGS. 1 and 2). (by a control module such as control module 116 or control module 216). Accordingly, gases output by the gas chromatography module 358 can be recycled through the gas chromatography module 358 to undergo further gas chromatography separation processes.

An optional purification module 370 is connected between the separation module 360 and the krypton storage module 326 . Krypton storage module 326 is described in detail above with reference to FIG. 3 and is not described again below for the sake of brevity.

Purification module 370 is configured to receive krypton output by separation module 360 . Purification module 370 is configured to purify received krypton. Any suitable purification process may be performed, such as pressure swing adsorption purification or cryogenic purification. Purification module 370 is configured to output purified krypton to either krypton storage module 326 or additional krypton storage module 426 (via optional polishing module 428 and/or buffer volume 430). there is The routing of purified krypton to either krypton storage module 326 or additional krypton storage module 426 is controlled by fifteenth valve 494 . The fifteenth valve 494 is a two-way valve. Fifteenth valve 494 is used to control the routing of purified krypton to either krypton storage module 326 or additional krypton storage module 426 (e.g., as described in detail above with reference to FIGS. 1 and 2). (by a control module such as control module 116 or control module 216).

Optional polishing module 428 may be the same as or similar to one or both of polishing modules 122, 222 described in detail above with reference to FIGS.
Buffer volume 430 may be a storage tank, container, or the like for (eg, temporarily) storing purified krypton before it is transferred to additional krypton storage module 426 . Accordingly, further embodiments of krypton recovery systems are provided.

FIG. 5 is a schematic diagram (not to scale) showing further details of a portion of microfabrication system 500 .
Elements common to the embodiments shown in Figures 3 to 5 are indicated using the same reference numerals.
The portion of microfabrication system 500 shown in FIG.

Process chamber 306, turbo pump 312, manifold 330, and pumping module 314 are as described in more detail above with reference to FIG. 3 and are not described again below for the sake of brevity.
Although only a single process chamber 306 and a single turbo pump 312 are shown in FIG. 5, in practice there are multiple process chambers 306 and turbo pumps 312 in this embodiment, each turbo It should be appreciated that a pump 312 is connected to each process chamber 306 .

In this embodiment, pump module 314 is configured to receive a purge gas (i.e., nitrogen) as indicated by arrow and reference numeral 340 in FIG. ) is further configured to receive a In this embodiment, this additional purge gas is an inert gas such as helium. The flow of additional purge gas to pump module 314 and/or manifold is indicated by arrows and reference numeral 550 in FIG. Additional purge gas flow to pumping module 314 may be regulated by ninth valve 552 . A ninth valve 552 is a control module (such as control module 116 or control module 216 described in detail above with reference to FIGS. 1 and 2) to control the flow of additional purge gas to pumping module 314 . module).

Additional purge gas may also be supplied to turbo pump 312 .
Pumping module 314 and/or turbo pump 312 are configured to mix or blend pumped exhaust gas with additional purge gas (and purge gas in the case of pumping module 314).
Pumping module 314 is configured to pump the mixed gas to first compressor 352 of krypton recovery system 510 .

In this embodiment, the krypton recovery system 510 includes a first compressor 352, a VPSA module 354, a getter module 502, a first pump 504, a third separation module 506, a second pump 508, a first buffer volume. 509 , a second buffer volume 512 and a plurality of krypton supplies 514 . The first compressor 352 and VPSA module 354 are as described in more detail above with reference to FIG. 3 and are not described again below for the sake of brevity.

Getter module 502 is configured to receive the gas stream output from VPSA module 354 . The getter module 502 comprises a getter, a deposit of reactive material placed in the gas flow path. The getter can be a coating applied to surfaces within the getter module 502 . The getter can be a titanium getter, eg a high temperature titanium getter. In operation, gas molecules collide with the getter material and bond with it chemically or by absorption. The getter thus removes a predetermined amount of gas from the gas stream. Specifically, in this embodiment, the getter is configured to remove one or more gases selected from the group consisting of PFCs, hydrogen, and nitrogen. Getter module 502 is further configured to supply the gas flow (after removal of the gas by the getter) to first pump 504 .

First pump 504 is configured to receive the gas flow output by getter module 502 . First pump 504 is configured to pump the received gas stream to third separation module 506 .

In operation, third separation module 506 receives a gas stream comprising a mixture of krypton and helium (and possibly other gases) from first pump 504 . A third separation module 506 is configured to process this gas stream to separate krypton from helium (and possibly other gases). Third separation module 506 may use any suitable gas separation technology. For example, the third separation module 506 can comprise a membrane, filter, or metal-organic framework (MOF) to separate krypton from helium.

Third separation module 506 is further configured to output separated helium gas and send the helium gas to turbo pump 312 and/or pump module 314, where turbo pump 312 and/or pump module 314 , helium is supplied as an additional purge gas. In this embodiment, the third separation module 506 separates the separated helium through a second pump 508 (which pumps the helium) and a first buffer volume 509 in which the helium can be temporarily stored. to turbo pump 312 and/or pumping module 314 . Therefore, the additional purge gas (ie helium) is reused/recycled.

The third separation module 506 distributes the separated krypton via a second buffer volume 512 as shown in FIG. 5, for example to the krypton storage module 326 or as shown in FIG. It is further configured to output to module 228 . Krypton storage module 326 may be similar or identical to storage module 126 described in more detail above with reference to FIG.

A second buffer volume 512 is configured to receive separated krypton from the third separation module 506 . Second buffer volume 512 is further configured to receive additional (eg, top-up) krypton from krypton supply 514 . Additional krypton flow from the krypton supply 514 is regulated or controlled by a plurality of sixteenth valves 520 . The sixteenth valve 520 is a two-way valve. A sixteenth valve 520 is provided to control the flow of krypton from the krypton supply 514 and the second buffer volume 512 (for example, the control module 116 described in detail above with reference to FIGS. 1 and 2 or (by a control module, such as control module 216). A second buffer volume 512 is configured to store a mixture of separated krypton from the third separation module 506 and additional krypton from the krypton supply 514 . Second buffer volume 512 is configured to output stored krypton to krypton storage module 326 .

Optionally, analysis module 516 is implemented to perform analysis of the composition of the mixture stored in second buffer volume 512 .
Accordingly, further embodiments of krypton recovery systems are provided.

In the above embodiments, krypton is used in the process chamber and recovered by a krypton recovery system. However, in other embodiments, the system uses different noble gases instead of or in addition to krypton. Examples of other suitable noble gases include, but are not limited to argon and xenon. Mixtures or admixtures of different noble gases can be used, such as any combination of argon, xenon, and krypton.
In the above embodiments, there are multiple process chambers. However, in other embodiments there is only a single process chamber.

100 microfabrication system 102 open loop exhaust gas treatment system 104 krypton supply 106 process chamber 108 pumping system 110 krypton recovery system 112 turbo pump 114 pump module 116 control module 118 purification module 120 separation module 122 polishing module 124 compression module 126 storage module 200 micromachining system 202 closed loop exhaust gas treatment system 204 krypton supply 206 process chamber 208 pumping system 210 krypton recovery system 212 turbo pump 214 pumping module 216 control module 218 purification module 220 separation module 222 polishing module 226 storage module 228 distribution module 300 micro Processing System 306 Process Chamber 310 Krypton Recovery System 312 Turbo Pump 314 Pumping Module 330 Manifold 340 Purge Gas Stream 350 Acid Gas Removal Module 352 First Compressor 354 Vacuum Pressure Swing Adsorption (VPSA) Module 355 Second Compressor 356 First storage module 358 gas chromatography module 360 separation module 364 carrier gas supply 367 system outlet 368 third compressor 370 purification module 326 krypton storage module 380 first valve 382 second valve 384 third valve 386 fourth valve 388 fifth valve 390 sixth valve 391 seventh valve 392 eighth valve 394 ninth valve 400 microfabrication system 402 PFC removal module 420 scrubber 424 cleaning liquid stream 426 additional krypton storage module 428 polishing module 430 buffer Volume 460 Additional separation module 466 Second storage module 468 Fourth compressor 484 Tenth valve 486 Eleventh valve 488 Twelfth valve 490 Thirteenth valve 492 Fourteenth valve 494 Fifteenth valve 500 Fine processing system 502 getter module 504 first pump 506 third separation module 508 first pump 509 first buffer volume 510 krypton recovery system 512 second buffer volume 514 supply of krypton 516 analysis module 552 ninth valve 520 tenth valve 550 helium flow

Claims (20)

a pumping system configured to pump a respective exhaust gas from each of a plurality of chemical etch process chambers and combine the exhaust gases to provide a combined exhaust gas;
a noble gas recovery system configured to process the combined exhaust gas to remove one or more noble gases therefrom;
A system with the pumping system is configured to receive a purge gas and combine the exhaust gas with the purge gas;
2. The system of claim 1, said system further comprising a vacuum pressure swing adsorption module configured to separate said purge gas from said combined exhaust gas. 3. The system of claim 2, wherein said purge gas is nitrogen. 4. The system of claim 2 or 3, wherein the vacuum pressure swing adsorption module is configured to supply the separated purge gas to the pumping system. 4. The noble gas recovery system comprises a gas chromatography separation module configured to separate one or more noble gases from other components of the combined exhaust gas using a gas chromatography process. 5. The system according to any one of 1-4. the gas chromatography separation module configured to receive a carrier gas used to transport the combined exhaust gas through the gas chromatography separation module;
6. The system of Claim 5, wherein the noble gas recovery system further comprises a separation module that separates one or more noble gases from the carrier gas. the gas chromatography separation module configured to receive a carrier gas used to transport the combined exhaust gas through the gas chromatography separation module;
7. The system of claim 5 or 6, wherein the noble gas recovery system further comprises an additional separation module for separating other components of the combined exhaust gas from the carrier gas. 8. The system of claim 6 or 7, wherein the separated carrier gas is reused or recycled by the gas chromatography separation module. 9. The system of any of claims 6-8, wherein the carrier gas is helium. 10. The system of any of claims 1-9, wherein the noble gas recovery system comprises an acid gas removal module configured to remove acid gases from the combined exhaust gas. 11. The system of any of claims 1-10, wherein the noble gas recovery system comprises a wet scrubber configured to perform a scrubbing process on the combined exhaust gas. 12. The system of Claim 11, wherein the noble gas recovery system comprises a dryer configured to perform a drying process on the gas stream output from the wet scrubber. The pump system is
a plurality of pumps, each configured to pump the exhaust gas from each of the plurality of process chambers;
a plurality of perfluorinated compound (PFC) removal or conversion modules configured to remove perfluorinated compound (PFC) from the gas stream output by said plurality of pumps or convert said PFC to other compounds; and,
with
13. The system of any preceding claim, wherein each of said plurality of PFC removal or conversion modules is connected to each of said plurality of pumps. 14. The system of claim 13, wherein one or more of said PFC removal or conversion modules comprises a plasma reactor. 15. The system of any of claims 1-14, wherein the noble gas recovery system comprises a getter module containing a getter. 16. The system of any of claims 1-15, wherein the getter is titanium. the pumping system is configured to receive a purge gas and combine the exhaust gas with the purge gas;
The rare gas recovery system comprises:
an acid gas removal module connected to the pumping system and configured to remove acid gases from the combined exhaust gas received from the pumping system;
a vacuum pressure swing adsorption module configured to receive a gas stream from the acid gas removal module and to separate the purge gas from the received gas stream;
receiving a gas stream from said vacuum pressure swing adsorption module and using a gas chromatography process to separate and separate one or more noble gases from other components of said gas stream received from said vacuum pressure swing adsorption module; 17. A system according to any preceding claim, comprising a gas chromatographic separation module configured to output one or more noble gases. The pumping system comprises:
a plurality of pumps, each configured to pump the exhaust gas from each of the plurality of process chambers;
a plurality of perfluorinated compound (PFC) removal or conversion modules configured to remove perfluorinated compound (PFC) from the gas stream output by said plurality of pumps or convert said PFC to other compounds; and,
each of the plurality of PFC removal or conversion modules is connected to each of the plurality of pumps, each of the plurality of PFC removal or conversion modules comprising a plasma;
The rare gas recovery system comprises:
a wet scrubber configured to perform a scrubbing process on the combined exhaust gas;
optionally, a dryer configured to perform a drying process on the gas stream output from said wet scrubber;
17. A system according to any preceding claim, comprising: The rare gas recovery system comprises:
receiving a gas stream from said wet scrubber or optionally said dryer and using a gas chromatography process from one or more other components of said gas stream received from said wet scrubber or optionally said dryer; 19. The system of claim 18, further comprising a gas chromatography separation module configured to separate the noble gases of and output the separated one or more noble gases. the pump system is configured to receive a purge gas and an additional purge gas and combine the exhaust gas with the purge gas and the additional purge gas;
The rare gas recovery system comprises:
a vacuum pressure swing adsorption module configured to receive a gas stream from the pumping system and to separate the purge gas from the received gas stream;
a getter module comprising a getter and configured to receive a gas stream from the vacuum pressure swing adsorption module and remove gas from the gas stream received from the vacuum pressure swing adsorption module;
receiving a gas stream from the getter module; separating one or more noble gases in the received gas stream from the additional purge gas in the received gas stream; and outputting the separated one or more noble gases. an isolation module configured to:
17. A system according to any preceding claim, comprising:

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