TW202133918A - Inert gas recovery from a semiconductor manufacturing tool - Google Patents

Abstract

An apparatus and method for treating process and cleaning gases exhausted from a semiconductor manufacturing tool during respective processing and cleaning phases and for recovering an inert gas from at least one of said treated process and cleaning gases. The apparatus comprises: a wet scrubber configured to receive and treat said exhaust gases; a solid phase gas adsorption separator configured to receive gases output by said wet scrubber via valve circuitry; and valve and control circuitry configured to route one of said cleaning and process gases output from said wet scrubber to bypass said solid phase gas adsorption separator and to route the other of said process and cleaning gases output from said wet scrubber to said solid phase gas adsorption separator; said solid phase gas adsorption separator being configured to differentially adsorb gases of different molecular characteristics onto a solid phase, and thereby separate the components of said received gases such that at least some of water vapour, and Nitrogen are removed from said gases and to output a gas comprising said recovered inert gas.

Description

Inert gas recovery from semiconductor manufacturing tools

The field of the present invention is related to the processing of gases discharged from a semiconductor manufacturing tool and the recovery of inert gases from the processed gases.

In the field of semiconductor manufacturing, semiconductor wafers are processed in a vacuum chamber in a multi-stage process, and different layers are accumulated on the wafer by passing different gases over the wafer during these stages. There is also a cleaning stage that is performed between stages to remove deposits left by a previous stage from the chamber. The gas passing through the vacuum chamber includes the gas used in the process and the gas used in the cleaning process, as well as the further gas that provides transportation of required chemicals and/or improved thermal management. These additional gases are generally chemically inert gases to avoid or at least reduce the occurrence of unwanted reactions. It is selected according to the required physical properties, for example, in some cases, helium can be used during the processing stage because it has good thermal conductivity and can facilitate effective thermal management. Some of these inert gases are expensive and increasingly difficult to obtain and it is desirable to be able to recover some of these gases from the exhaust gases of semiconductor tools.

Once discharged from the semiconductor tool, processing gas is also required because many chemicals used during processing and cleaning may be toxic. Generally, a burner is used to treat exhaust gas from semiconductor tools, followed by further treatment such as wet scrubbing. Using a burner involves adding air or oxygen and fuel to the gas stream. This makes it significantly more difficult to recover the inert gas from the original exhaust.

It is desirable to be able to process gas exhausted from a semiconductor tool and recover at least one selected inert gas from the processed exhaust gas.

A first aspect provides an apparatus for processing process and cleaning gases discharged from a semiconductor manufacturing tool during respective processing and cleaning stages and for recovering an inert gas from at least one of the processed processes and cleaning gases , The equipment includes: a wet scrubber configured to receive and process the exhaust gas; and a solid-phase gas adsorption separator configured to receive the wet scrubber through a valve circuit system And the valve and control circuit system, which are configured to make one of the cleaning and process gases output from the wet scrubber bypass the solid-phase gas adsorption separator and make it from The other of the processes and clean gas output from the wet scrubber is routed to the solid-phase gas adsorption separator; the solid-phase gas adsorption separator is configured to differentially adsorb gases with different molecular characteristics to On a solid phase and thereby separate the components of the receiving gases so that at least some water vapor and nitrogen are removed from the gases and output a gas including the recovered inert gas.

The inventors of the present invention have realized that it is desirable to recover at least some of the inert gas used in a semiconductor manufacturing tool. It also recognizes that when processing or reducing the gas output from this tool, when a burner is used, the addition of air and fuel to the gas stream makes it difficult to recover any gas. Therefore, a system is provided that does not use a burner for volume reduction but uses a wet scrubber to process the process gas and to clean the gas during the cycle. Then, a further processing stage configured to separate the desired inert gas from the processed gas stream is provided.

Although the use of a wet scrubber avoids introducing fuel and air into the exhaust stream, it introduces water vapor. In addition, in the exhaust flow of many semiconductor manufacturing tools, flushing gas in the form of nitrogen is introduced to reduce the deposition of particles in the pump and the duct, and the nitrogen cannot be removed by a wet scrubbing process. Therefore, although the gas processed by the wet scrubber may have removed many toxic chemicals, it will leave a large amount of nitrogen and water vapor.

The inventors of the present invention have realized that a solid gas adsorption separator can be used to remove these components from the gas stream. This separator uses solid molecules to preferentially adsorb different components of the gas stream. When the molecules to be removed are known, solid particles can be selected accordingly. For a semiconductor manufacturing tool, different stages of manufacturing and cleaning will cause different gases to flow through the tool. Therefore, the control and valve circuit system is used to route the gas flow from which the inert gas is recovered to the separator and route the gas from other stages in a different direction, in some cases directly to the exhaust. The gas stream routed to the separator will have one component adsorbed in the first part of the separator, and other components will be adsorbed in the subsequent part. The outlet gas will include the desired unadsorbed components and a smaller amount of other gases. The advantage of this separator is that it uses physical separation and can therefore be regenerated by only reversing the flow and changing the physical conditions to release the adsorbed gas that can be discharged from the system. This makes it a cost-effective and efficient separator.

In some embodiments, the apparatus further includes a chemical purifier configured to receive the gas output from the solid-phase gas adsorption separator; the chemical purifier is configured to receive the output from the solid-phase gas adsorption separator The gas and output the further purified gas.

In some embodiments, the gas recovered from the physical separator is sent to a subsequent purification stage by using chemical separation to remove further impurities. Then, the recovered inert gas can be collected or exported back to the tool. Chemical purification is very effective, but the chemicals in the purifier are used up and the procedure becomes very expensive, unless many undesirable components are removed before chemical separation.

In some embodiments, the valve and control circuitry are configured to route the gas output from the chemical purifier back to the semiconductor manufacturing tool.

In some cases, the recovered inert gas can be optionally routed back to the tool and reused in subsequent stages. In this regard, many substances that are present in the gas stream together with the inert gas are substances that are present in the vacuum chamber during the semiconductor processing or cleaning stage. Therefore, when the inert gas is recovered and reused in the process, the required purification amount can be reduced, because a small amount of these other gases will not unduly affect the processing and this can lead to a lower cost or smaller volume system.

In other embodiments, the equipment includes a gas collection unit for collecting the recovered inert gas.

In an alternative configuration, the gas may not be recycled directly but may be collected. In some cases, the gas can then be stored before being removed to a remote facility where further processing and recovery of the high-value component gas is completed. Alternatively, the gas output from the chemical purifier is collected and stored for a temporary period and then recycled. This temporary storage provides some buffering and allows the system to adapt to the continuous consumption of these gases through various processing chambers including processing tools.

In some cases, the gas output from the chemical purifier is routed back to the tool, but mixed with fresh gas provided by a manufacturing facility or a local bottled source to further adjust the total gas purity or meet the consumption requirements of various chambers including processing tools .

In some embodiments, the control circuit system is configured to indicate to the semiconductor manufacturing tool the quantity and purity of the inert gas returned to the tool.

When the inert gas is returned to the tool, there may be advantages associated with indicating to the tool the purity and quantity of the inert gas being recycled. This can be determined by using an analyzer and flow meter to detect the flow and purity of the gas. This allows the tool to adjust the input of other gases to the tool to adapt to the amount of impurity gases such as water vapor or nitrogen present in the inert gas and/or to mix the recovered gas and one of the known purity storage supplies to provide the required amount of inert gas and quality.

In some embodiments, the solid-phase gas adsorption separator includes an input port for receiving gas from the wet scrubber, an exhaust port for outputting separated exhaust gas, and an outlet for outputting processed gas to An output port of the chemical purifier; the valve and control circuit system are configured to allow gas to flow into the input port during the processing stage and periodically when reversing the gas flow through the separator for regeneration of the separator Allow exhaust gas to flow out of the exhaust port.

As mentioned earlier, one of the advantages of the solid-phase gas absorption separator is that it can be regenerated. Therefore, in some embodiments, the valves and control circuitry that control the routing of the exhaust gas to this separator can also be configured to allow exhaust gas to be discharged from the separator when the airflow is reversed during the regeneration of the separator.

Although the solid-phase gas absorption separator can have many forms, in some embodiments, it includes one of a pressure swing adsorber or a vacuum pressure swing adsorber.

Although this equipment is applicable to different semiconductor processes, in some embodiments, the semiconductor process includes sub-atmospheric chemical vapor deposition.

Sub-atmospheric chemical vapor deposition (SACVD) is a process that uses helium for thermal management. The cost of helium is increasing and it is becoming more and more difficult to obtain an inert gas. Therefore, the ability to recover the inert gas used in this procedure is particularly advantageous.

In some embodiments, the wet scrubber is configured in one or more stages to remove CO ₂ and particulate silica from the process gases during the processing stage and from the cleaning stage during the cleaning stage Wait for cleaning gas to remove fluoride.

In some embodiments, the wet scrubber includes a two-stage wet scrubber that is configured such that a first stage uses a quantitatively added alkali water and a second stage uses demineralized water.

In some embodiments, the wet scrubber includes a two-stage wet scrubber configured so that wastewater from each stage is redirected for internal reuse between stages.

One potential problem with wet scrubbers is that the water used to remove useless and in some cases toxic chemicals must be disposed of and this can be expensive. It has a multi-stage wet scrubber and redirects waste water for internal reuse between stages. It also controls any reagent addition designed to optimize the washing performance of each stage. It provides an effective way to control the wet scrubber And provide effective cleaning and waste water reduction.

In some embodiments, the valve and control circuit system are configured to route the process gases output from the wet scrubber to the solid-phase gas adsorption separator; the solid-phase gas adsorption separator is configured To separate the components of the receiving gases so that at least some water vapor and nitrogen are removed from the gases and output a gas including the recovered inert gas.

Although the equipment can be used to recover inert gas from the process gas or clean gas depending on which gas is routed to these separators, when the process gas is routed, the solid-phase gas adsorption separator can be configured to not only remove water vapor and Nitrogen and also remove oxygen that can be used in the processing stage. In this regard, during a processing stage, the inert gas can not only be used to transport the different chemicals required for the wafer, but it can also be required to have other properties such as high thermal conductivity to improve thermal management. Therefore, the choice of inert gas can be restricted by these requirements and it is possible to choose more expensive inert gas. During the cleaning phase, the inert gas is generally only used as a transport gas and a cheaper gas can be selected. For this reason, the inert gas used in the processing stage is generally an inert gas that is beneficial to recovery, and therefore, in some embodiments, a device that only recovers inert gas from the process gas is provided.

In some embodiments, the recovered inert gas includes helium.

Due to its high thermal conductivity, helium is used as an inert gas system in some processing stages. Helium is becoming more and more difficult to obtain, so the ability to recover helium will be advantageous.

In some embodiments, the chemical separator is configured to remove one of O ₂ , H ₂ O, and N ₂ through an irreversible chemical reaction as a consumable separator.

As previously mentioned, chemical separators use chemical reactions to separate components and when these come from process gas, these components can be oxygen, water vapor, and nitrogen. The chemical separator uses an irreversible chemical reaction and thus a consumable separator. In fact, chemical separation is effective, but it is more expensive due to the consumption of chemicals. Therefore, where possible, use a physical separator before the chemical separator to remove unnecessary substances as low as a first content (which can be tens of parts per million of the gas flow) and use a chemical separator to further reduce The amount is favorable. This allows the chemical separator to have a longer life while still achieving a high purity. Similarly, if the purity of the required gas stream is low, it can be attributed to the recirculation gas and the "impurity" gas input to the processing tool is adjusted to take the impurities into account. It can also be extended without removing so many "useless" chemicals. The life of the purifier.

In some embodiments, the device is configured to recover an inert gas from both the process gas and the cleaning gas. The device further includes another solid-phase gas adsorption separator and another chemical purifier. Configured to receive gas from the solid-phase gas adsorption separator; wherein the valve and control circuit system are configured to route the clean gas output from the wet scrubber to the other solid-phase gas adsorption and separation And route the program gases output from the wet scrubber to the solid-phase gas adsorption separator.

Although as mentioned above, the process gas will generally have more expensive inert gas and when recovering this inert gas may be most advantageous, it may be advantageous to remove the inert gas from the cleaning gas in some cases. This can be done as an alternative or in addition to removing the inert gas from the process gas. When both inert gases are to be removed, there will generally be two separators and two chemical purifiers with specific compositions suitable for different gas streams. In this case, the valve and control circuit system will route the gas to the appropriate separator and purifier. In other embodiments, different processing stages can use different gases and require different separators, and in this case, the valve and control circuit system can be configured to route gases from different processes to be configured for Different physical separators of related gas composition.

In some embodiments, the valve and control circuit system is configured to receive signals from the semiconductor processing tool and control at least one of air flow and operations of wet scrubbers and physical separators based on the received signals.

The processing and recovery of inert gas can be synchronized with the operation of semiconductor manufacturing tools to improve recovery efficiency and product gas purity. In this regard, the composition of the gas flow through the tool and the gas exhausted from the tool depends on the process taking place within the tool. Therefore, linking the control of the treatment and recovery system to the tool allows the gas treatment to be optimized for current conditions and gas composition.

A second aspect provides a method for processing process and cleaning gases discharged from a semiconductor manufacturing tool during respective processing and cleaning stages and for recovering an inert gas from at least one of the processed processes and cleaning gases The method includes: using a wet scrubber to treat the exhaust gas; routing one of the cleaning and process gases output from the wet scrubber to bypass a solid-phase gas adsorption separator; The other of the clean or process gases passes through a solid phase gas adsorption separator to separate nitrogen and water vapor from the inert gas.

In some embodiments, the method further includes passing the gas output from the solid-phase gas adsorption separator through a chemical purifier to further separate nitrogen and water vapor from the inert gas; and outputting a gas including the recovered inert gas.

In some embodiments, the method further includes routing the gases output from the chemical purifier back to the semiconductor manufacturing tool.

In other embodiments, the method further includes collecting the recovered inert gas in a gas collection unit.

In some embodiments, the method further includes indicating to the semiconductor manufacturing tool the quantity and purity of the inert gas returned to the tool.

Further specific and better aspects are described in the attached independent and subsidiary technical solutions. The features of the subsidiary technical solution can be appropriately combined with the features of the independent technical solution, and can be combined with features other than those clearly stated in the scope of the patent application.

When a device feature is described as being operable to provide a function, it should be understood that this includes a device feature that provides the function or is adapted or configured to provide the function.

Before discussing the embodiments in more detail, an overview will be provided.

A device for processing exhaust from a semiconductor tool and for recovering an inert gas from the processed gas is disclosed. Use of a process that does not contain a burner so that oxygen and fuel are not added to the exhaust gas. A wet scrubber is used, and the exhaust therefore contains additional water vapor. In addition, in many cases, a flushing gas, which is generally in the form of nitrogen, is added to the exhaust stream to reduce particle deposition in the pump and duct. Therefore, the processed gas will remove nitrogen and water vapor and may also have oxygen, where the processed gas system comes from one of the process gases such as SACVD.

A physical adsorption component (such as a pressure swing or vacuum pressure swing adsorber) can be used to remove most of these useless gases, in which the inert gas that adsorbs different molecules and is to be recovered flows through in a more concentrated form. The advantage of these purifiers is that they can be regenerated to make them cost-effective. The purity of the inert gas can be further improved by using a chemical purifier. The processing equipment may include the chemical purifier and receive and process the gas from the physical separator or the chemical purifier may be located remotely, and may store the gas and then deliver the gas to a purification field. When the gas is purified in situ by the chemical purifier, it can be recycled to the processing tool.

Figure 1 shows a device according to an embodiment. The equipment includes a semiconductor manufacturing tool 10, which in this embodiment is used to perform a vacuum chamber of a SACVD process. This tool 10 is evacuated using a dry pump 15. A flushing gas (which in this case is nitrogen) is added to the gas flow at the pump to reduce powder deposits in the pump and ducts. The vapor leaving the pump during the processing stage includes nitrogen, ozone and/or oxygen, helium, water vapor, carbon dioxide and silicon dioxide, the latter being in the form of a powder. The vapor leaving the pump during the cleaning phase contains argon, silicon fluoride, fluorine, nitrogen, and some water vapor.

Then, the flow passes through a wet scrubber. In this embodiment, the wet scrubber is formed in two stages 20a and 20b. The first stage 20a is mainly configured to remove the remaining F ₂ from the end of the chamber cleaning step without forming a highly toxic gas OF ₂ . In order to avoid the _{formation of OF 2} , potassium hydroxide (KOH), which increases the pH value of the solution, is "quantified" in the water. The second stage wet scrubbing 20b uses demineralized water and is designed to reduce the transfer of powder and other dissolved materials to subsequent physical separator stages that may be susceptible to contamination.

The flow leaves the wet scrubber 20b of the second stage and passes to the valve circuit system 30 controlled by the control circuit system 32. The control circuit system 32 receives a signal from the tool 10 indicating that the program is currently being executed. The valve circuit system 30 diverts the air flow from the wet scrubber to the physical separator 40 (which in this case is a pressure swing and/or vacuum pressure swing adsorber) or directly to the exhaust port 35. The physical separator is configured to remove specific gases, and in this embodiment, it is configured to remove nitrogen, oxygen, and water vapor by physically adsorbing these molecules to the solid particles in the separator.

The physical separator 40 is connected to a chemical separator 50, which further purifies the gas to leave mainly the required inert gas (helium in this case) and some traces of nitrogen and possibly oxygen and water vapor. In this embodiment, the inert gas is recirculated to the tool 10 via the conduit 52. In this embodiment, an analyzer and flow detector 60 determine the composition and flow rate of the recirculated gas and transmit a signal indicating this to the control circuit system 32. The control circuit system 32 transmits information to the tool 10, and the tool 10 controls the addition of different gases to the tool during different processing and cleaning stages according to the received information.

Considering the airflow used in an example of a system in a SACVD process and starting from the pump, we found that: • Add N ₂ flushing at the dry pump to facilitate powder disposal and reduce powder deposition in the ducts and pumps: SACVD process Produce a lot of powder. • There is a risk of TEOS condensation during the room bypass, which is mitigated by the use of a high pump temperature and active temperature management of adjacent ducts. • The concentration of He leaving the pump is usually <10% by volume. The first wet washing stage:

The first wet scrubbing stage is mainly configured to remove remaining F ₂ from the end of the chamber cleaning step without forming a highly toxic gas OF ₂ . To avoid the _{formation of OF 2} , potassium hydroxide (KOH), which increases the pH of the solution, is "quantified" in the water, and it can also be heated to promote optimal or at least improved reaction kinetics.

Other etching by-product SiF ₄ will also be removed.

During the deposition step, this high pH brings the benefit of also scrubbing CO ₂ from the exhaust gas. The K and OH ions in the water will also react with the SiO ₂ powder to get some SiO ₂ into the solution.

Therefore, the consumption of water and KOH in the first washing stage may be very high to push up reagent costs and processing costs.

It is possible to make some reflux of this water as much as possible. The second wet washing stage:

The second stage of wet washing uses demineralized water and is designed to reduce the transfer of powder and other dissolved materials to subsequent PSA/VSA (pressure swing adsorption and/or vacuum swing adsorption) stages that may be easily contaminated.

A conservative assumption is that this stage will consume 10 lpm to 20 lpm of fresh water without backflow. This water can be reused by storing this water or by adding KOH to this water quantitatively and leading it to the first stage.

This stage will be operated at room temperature to reduce water transfer to separation stage 40. Physical separator, PSA/VSA level:

This stage is designed to separate He from the wet N ₂ and O ₂ from the second stage wet scrubber. In this embodiment, the gas from the cleaning step (mainly Ar) is not processed, and the gas is directly turned to waste. In other embodiments, such as shown in Figure 2, the cleaning gas can be diverted to other PSA/VSA and chemical separators to recover argon.

The stage needs to be carefully designed to maximize the recovery efficiency of He and also minimize or at least reduce O ₂ pollution in the He product. The pollution leaving this level will finally determine the life of the final stage polishing purifier 50.

Stage 40 is driven by some kind of variable pressure: a mechanical compressor (PSA) after the wet scrubber or an additional vacuum pump (VSA) for removing exhaust gas. Due to the high water content from the wet scrubber, a VSA may be better. Polishing purifier ( chemical separator ) 50 :

The purpose of this level is to remove trace amounts of H ₂ O and O ₂ to leave only a small amount of N ₂ in our He product gas. Exhaust gas

These mainly include N ₂ and should be ventilated. Product gas

In this embodiment, these are returned to the tool either directly or after mixing with a fresh He supply. In other embodiments, it can be compressed and sent off-site for further processing.

In the above example, the equipment is used for SACVD and in the deposition process, the following chemicals are used for the following reactions: TEOS+ozone→silica dioxide+water+carbon dioxide Si(OC ₂ H ₅ ) ₄ +8 O ₃ [+N ₂ + He]àSiO ₂ +10 H ₂ O+8 CO ₂ [+N ₂ +He] • H ₂ O is added to increase/increase density and is used for higher AR • Supply excess oxygen (O ₃ and O ₂ )( About 10% utilization rate) Room cleaning uses Ar+NF ₃

This gives the program gas one of the following first-stage exhaust flow: _⁻ N ₂ ~96+30~125 _⁻ O ₃ ~30 _⁻ He~15 _⁻ CO ₂ ~3 _⁻ H ₂ O~4 _⁻Silica powder (~ 4 g/min)

The total flow is about 175 slm, He is present at about 9% v/v, and O ₃ and silicon dioxide need to be reduced.

The recovery of helium gas has the following purification steps: 1. Remove silica powder 2. Remove ozone and CO ₂ 3. Dry gas 4. _{Extract He from N 2} , O ₂ and H ₂ O 5. Final polishing (O _2. H ₂ O) • There will be a small amount of N _{2 in the} recovery of He, and there is a trade-off between the recovery efficiency and the N _{2 concentration.} • Can use <0.5% N _{2 to} achieve> 90% recovery • Can use a PoU (used on demand) analyzer to verify the N ₂ concentration with an accuracy better than 10 ppm • This is acceptable in many embodiments, because The program uses N ₂ , and the total uncertainty is generally within the uncertainty of N ₂ MFC (mass flow control).

The problem of recycling is the cleaning step: Room cleaning is based on fluorine chemistry, using NF ₃ as the source of _F⁻This brings a problem to the wet scrubbing stage, because at a pH of about 7 (pure water), the scrubber will produce Highly toxic OF ₂ . • The better solution to this problem is to increase the pH by quantitatively adding potassium hydroxide (KOH) • This also provides an _{opportunity to wash CO 2} : 2 KOH _(aq) +CO ₂ àK ₂ CO _{3 (aq)} + H ₂ O • In some cases, efficient washing may require an increase in scrubber temperature> 60°C _⁻Higher water temperature pushes up the cost of the water system because many plastics are no longer suitable. • Single-stage water washing cannot efficiently remove finer silica powder, and the moist product gas will maintain strong alkalinity due to the control of the KOH required for the formation of _{OF 2 ⁻For} many embodiments, the two-stage wet washing system Preferably, and this will push up the water consumption beyond that of a conventional combustion/wet abatement system, but allow some recirculation of the water.

Fig. 2 shows an embodiment similar to the embodiment of Fig. 1, but in this case, both the clean gas and the process gas are processed, and the valves 30 and 31 are controlled by the control circuit system 32 to send the gas to the first physical separator 40 or second physical separator 42. There is also the possibility of sending the gas directly to the exhaust port.

In this embodiment, the physical separator 40 is configured to separate helium and process gas, and the physical separator 42 is configured to separate argon and clean gas. In this embodiment, the gas is no longer recycled, but the gas is output from the physical separator and compressed and stored before being removed to the off-field purifier for further purification of the gas to recover helium and argon, respectively.

FIG. 3 shows a flowchart illustrating steps in a method of processing a program stream and recovering an inert gas from the program stream according to an embodiment.

In this method, in step S10, gas is received from the exhaust gas of a semiconductor processing tool. In step S20, a wet scrubber is used to process the gas, and then in step S30, it is determined whether the output gas is a program gas. When the gas output is the process gas, it is sent to a physical separator, where water vapor, nitrogen and oxygen are removed in step S50. When the output gas system comes from a clean cycle gas, the gas is discharged from the equipment in step S40. The gas output from the physical separator is mainly helium and this gas can be collected in step S60, which can then be further processed using a chemical purifier and/or recycled back to the processing tool.

In summary, this application discloses a method and equipment for recovering inert gas (specifically, He gas) from a semiconductor process such as a SACVD (sub-atmospheric chemical vapor deposition) process. The embodiment uses a novel combination of alkaline wet scrubbing, pressure swing or vacuum rotary adsorption, and in some cases PoU purification. These procedures are closely integrated with sub-manufacturing vacuum systems and tools. SACVD (Sub-Atmospheric Pressure Chemical Vapor Deposition) is a process used to deposit high-density SiO ₂ films to fill trenches or provide isolation between metal layers on semiconductor devices. The program uses an appropriate amount of helium during deposition.

Although the illustrative embodiments of the present invention have been disclosed in detail herein with reference to the accompanying drawings, it should be understood that the present invention is not limited to the precise embodiments and those skilled in the art may not deviate from the scope of the appended patent application and its equivalents. Various changes and modifications are made to the present invention while defining the scope of the present invention.

10: Semiconductor manufacturing tools 15: Dry pump 20a: Wet scrubber stage 20b: Wet scrubber stage 30: Valve 31: Valve 32: control circuit system 35: exhaust port 40: physical separator 42: physical separator 50: Chemical purifier 52: Catheter 60: Analyzer S10: steps S20: steps S30: steps S40: Step S50: steps S60: steps

The embodiments of the present invention will now be further described with reference to the accompanying drawings, in which:

Figure 1 shows a device according to an embodiment;

Figure 2 shows a device according to another embodiment; and

FIG. 3 shows a flowchart showing the steps in a method for treating exhaust gas and recovering an inert gas from the treated gas.

10: Semiconductor manufacturing tools

15: Dry pump

20a: Wet scrubber stage

20b: Wet scrubber stage

30: Valve

32: control circuit system

35: exhaust port

40: physical separator

50: Chemical purifier

52: Catheter

60: Analyzer

Claims (16)

A device for processing a process and cleaning gas discharged from a semiconductor manufacturing tool during respective processing and cleaning stages and for recovering an inert gas from at least one of the processed process and cleaning gas, the device comprising: A wet scrubber configured to receive and process the exhaust gas; A solid-phase gas adsorption separator configured to receive the gas output from the wet scrubber via a valve circuit system; and A valve and control circuit system, which is configured to route one of the cleaning and process gases output from the wet scrubber to bypass the solid-phase gas adsorption separator and make the wet scrubber The other one of the output procedures and clean gas is routed to the solid-phase gas adsorption separator; The solid-phase gas adsorption separator is configured to differentially adsorb gases of different molecular characteristics onto a solid phase and thereby separate the components of the receiving gases so that at least some water vapor and nitrogen are removed from the gases and The output includes one of the recovered inert gases. For the equipment of claim 1, the equipment further includes a chemical purifier configured to receive the gas output from the solid-phase gas adsorption separator; the chemical purifier is configured to receive the solid-phase gas adsorption separator Export the gas and export the further purified gas. Such as the equipment of claim 1 or 2, wherein the valve and control circuit system are configured to route the gas output from the chemical purifier back to the semiconductor manufacturing tool. Such as the equipment of claim 1 or 2, which includes a gas collection unit for collecting the recovered inert gas. Such as the equipment of claim 3, wherein the control circuit system is configured to indicate to the semiconductor manufacturing tool the quantity and purity of the inert gas returned to the tool. The device of any one of the preceding claims, wherein the solid-phase gas adsorption separator includes an input port for receiving gas from the wet scrubber, an exhaust port for outputting separated exhaust gas, and Output the processed gas to an output port of the chemical purifier; The valve and control circuitry are configured to allow gas to flow into the input port during the processing stage and periodically allow exhaust gas to flow out of the exhaust port when periodically reversing gas flow through the separator for regeneration of the separator. The device of claim 6, wherein the solid-phase gas adsorption separator includes one of a pressure swing adsorber and a vacuum pressure swing adsorber. An apparatus according to any one of the preceding claims, wherein the semiconductor manufacturing process includes sub-atmospheric chemical vapor deposition. An apparatus as in any one of the preceding claims, wherein the wet scrubber is configured into one or more stages to remove CO ₂ and particulate silica from the process gases during the processing stage and in the cleaning During the phase, fluoride is removed from the cleaning gases. Such as the equipment of claim 9, wherein the wet scrubber includes a two-stage wet scrubber that is configured so that a first stage uses quantitatively added alkali water and a second stage uses softened water. The wastewater is redirected for internal reuse between stages. The equipment of any one of the foregoing claims, wherein the valve and control circuit system are configured to route the process gases output from the wet scrubber to the solid-phase gas adsorption separator; The solid-phase gas adsorption separator is configured to separate the components of the receiving gases such that at least some water vapor, oxygen, and nitrogen are removed from the gases; and The chemical purifier is configured to remove at least some of any residual water vapor, oxygen, and nitrogen from the gases and output a gas including the recovered inert gas. Such as the equipment of claim 11, wherein the recovered inert gas includes helium. Such as the equipment of claim 11 or 12, wherein the chemical separator is configured to remove one of O ₂ , H ₂ O, and N ₂ through an irreversible chemical reaction as a consumable separator. The equipment of any one of the preceding claims, the equipment is configured to recover an inert gas from both the process gas and the cleaning gases, the equipment further includes: Another solid-phase gas adsorption separator and another chemical purifier, the other chemical purifier being configured to receive gas from the solid-phase gas adsorption separator; wherein The valve and control circuit system are configured to route the clean gas output from the wet scrubber to the other solid phase gas adsorption separator and enable the processes output from the wet scrubber The gas is routed to the solid-phase gas adsorption separator. The device of any one of the preceding claims, wherein the valve and control circuit system are configured to receive signals from the semiconductor processing tool and control the airflow and the wet scrubber and physical separator according to the received signals At least one of the operations. A method for processing process and cleaning gases discharged from a semiconductor manufacturing tool during respective processing and cleaning stages and for recovering an inert gas from at least one of the processed processes and cleaning gases, the method comprising: Use a wet scrubber to treat the exhaust gas; Routing one of the cleaning and process gases output from the wet scrubber to bypass a solid phase gas adsorption separator; Passing the other of the clean or process gases through the solid-phase gas adsorption separator to separate nitrogen and water vapor from the inert gas; and The output includes one of the recovered inert gases.

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