Pest Control Devices and Methods
A pollution control device with a detoxification chamber, wet scrubber, and catalyst bed effectively treats exhaust gases from semiconductor manufacturing, addressing high energy consumption and inconsistent compound levels by using catalyst beds to reduce pollutant concentrations at lower temperatures.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- EDWARDS LTD
- Filing Date
- 2023-02-16
- Publication Date
- 2026-07-29
AI Technical Summary
Existing pollution control technologies face challenges in effectively and efficiently removing perfluoroelastomers (PFCs) and other compounds from exhaust gas streams in semiconductor manufacturing, as they require high energy consumption and struggle to maintain consistent compound levels for adequate treatment.
A pollution control device comprising a detoxification chamber, a wet scrubber, and a catalyst bed is used to treat exhaust gases, where the catalyst bed reduces the concentration of harmful compounds like PFCs, hydrocarbons, and combustion by-products to environmentally acceptable levels, operating at lower temperatures and reducing energy consumption by utilizing exothermic reactions.
The system achieves efficient removal of pollutants at lower temperatures, reducing energy consumption and improving the performance of exhaust gas treatment systems by utilizing catalyst beds to treat compounds that are difficult to remove otherwise.
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Abstract
Description
[Technical Field]
[0001] The field of this invention relates to pollution control devices and methods. [Background technology]
[0002] Pollution removal equipment is known and is commonly used, for example, to treat exhaust gas streams from manufacturing process tools used in the semiconductor or flat panel display manufacturing industries. During such manufacturing, residual perfluoroelastomers (PFCs) and other compounds are present in the exhaust gas streams pumped from the processing tools. PFCs are difficult to remove from exhaust gases, and their release into the environment is undesirable because they are known to have a relatively high greenhouse effect.
[0003] Known abatement devices utilize combustion to remove PFCs and other compounds from exhaust gas streams. Such other compounds may include, but are not limited to, silanes (SiH4), nitrogen oxides (N2O), or NF3. Generally, the exhaust gas stream is a nitrogen stream containing the aforementioned process gases. Often, fuel gas is mixed with the exhaust gas stream, and the gas stream mixture is delivered into a combustion chamber laterally surrounded by the outlet surface of a perforated gas burner. The fuel gas and air are supplied simultaneously to the perforated burner to influence flameless combustion at the outlet surface, and the amount of air passing through the perforated burner is required to be sufficient not only to supply fuel gas to the burner but also to consume all combustible material in the gas stream mixture injected into the combustion chamber. Electrically heated abatement devices and plasma abatement devices are also known and operate in a similar manner. [Overview of the project] [Problems that the invention aims to solve]
[0004] While technologies exist for treating exhaust gas flows, each has its own drawbacks. Therefore, there is a need for improved technologies for treating exhaust gas flows. [Means for solving the problem]
[0005] According to a first embodiment, a detoxification device is provided for detoxifying an exhaust flow from a semiconductor processing tool, the detoxification device comprising: a detoxification chamber configured to receive the exhaust flow and supply a detoxified exhaust flow; a wet scrubber located downstream of the detoxification chamber and configured to receive the detoxified exhaust flow and supply a cleaned exhaust flow; and a catalyst bed located downstream of the wet scrubber and configured to receive the cleaned exhaust flow and supply a treated exhaust flow.
[0006] The first aspect recognizes that a problem with existing equipment is that it can be difficult to achieve the necessary conditions in the abatement chamber to abate compounds and / or abatement by-products in the exhaust flow to a level that can be discharged from the abatement equipment. Furthermore, the composition of PFCs and other compounds may not be maintained at a constant level in the exhaust gas, which can present further challenges in supplying a well-treated exhaust flow.
[0007] Accordingly, a pollution control device is provided. The pollution control device may be for polluting the discharge flow. The discharge flow may be from semiconductor processing tools. The pollution control device may comprise a pollution chamber. The pollution chamber may be configured or positioned to receive the discharge flow. The pollution chamber may be configured or positioned to pollute the discharge flow in order to supply the polluted discharge flow. The pollution control device may comprise a wet scrubber. The wet scrubber may be located or positioned downstream of the pollution chamber. The wet scrubber may be configured or adapted to receive the polluted discharge flow. The wet scrubber may wash the polluted discharge flow and supply the washed discharge flow. The pollution control device may comprise a catalyst bed. The catalyst bed may be located or positioned downstream of the wet scrubber. The catalyst bed may be configured or positioned to receive the washed discharge flow. The catalyst bed may assist the catalytic reaction of the washed discharge flow and supply the treated discharge flow. The treated effluent may contain compounds removed from the washed effluent by catalytic reaction with the catalyst bed. Thus, undesirable compounds present in the treated effluent—either already present in the effluent, not sufficiently effluentized by the effluent chamber, or as effluent by-products or reactants generated within the effluent chamber—can be treated, removed, or have their concentration reduced by the catalyst bed before being released by the effluent system. This helps improve the performance of the effluent system by removing compounds that might otherwise be difficult or energy-intensive to remove using only the effluent chamber.
[0008] The detoxification chamber can be configured to supply a detoxified exhaust stream containing at least one of at least one combustion by-product and at least one hydrocarbon, and the catalyst bed can be configured to reduce the concentration of at least one of at least one combustion by-product and at least one hydrocarbon present in the treated exhaust stream. Thus, combustion or detoxification by-products and / or hydrocarbons can be treated, removed, or their concentration reduced using the catalyst bed.
[0009] The detoxification chamber can be configured to supply at least one of at least one combustion byproduct and at least one hydrocarbon to the detoxified exhaust stream at a concentration above a threshold, and the catalyst bed can be configured to reduce the concentration of at least one of at least one combustion byproduct and at least one hydrocarbon present in the treated exhaust stream to below a threshold. Thus, the catalyst bed can reduce the concentration of combustion byproducts or hydrocarbons to typically below an environmentally acceptable threshold.
[0010] The abatement chamber can be configured to supply at least one of at least one combustion byproduct and at least one hydrocarbon to the abated exhaust stream at a concentration higher than a threshold, at a lower temperature than required to supply at least one of at least one combustion byproduct and at least one hydrocarbon to the abated exhaust stream at a concentration lower than a threshold. Thus, the abatement chamber can operate at a lower temperature than required to operate at in order to supply combustion byproducts and / or hydrocarbons at a concentration lower than a threshold; in other words, the abatement chamber can operate at a lower temperature, which leads to higher concentrations of combustion byproducts or hydrocarbons, but which can then be treated by the catalyst bed. This helps reduce the overall energy consumption of the abatement system.
[0011] The detoxification chamber can be configured to supply the detoxified exhaust stream with at least one of several combustion by-products and several hydrocarbons at their respective initial concentrations, and the catalyst bed can be configured to carry out several catalytic reactions on the washed exhaust stream and supply the treated exhaust stream with at least one of several combustion by-products and several hydrocarbons at concentrations lower than their respective initial concentrations. Thus, several different catalysts can be provided, each catalyst capable of catalytic reactions with one or more relevant combustion by-products and / or hydrocarbons to reduce their concentrations.
[0012] The catalyst bed is used for the direct decomposition of N2O and NOX It can include at least one catalyst material for at least one of the reduction and / or decomposition of , and the oxidation of at least one of CO and hydrocarbons.
[0013] The catalyst bed can include a catalyst material including at least one of a metal oxide material, a metal oxide, and a noble metal on a support.
[0014] The support can include at least one of titanium, aluminum, zirconium, and silicon-based oxides. Such examples include silica, silicalite, titanium aluminosilicate oxide, zirconia, alumina, and zeolite.
[0015] The noble metal can include at least one platinum group metal.
[0016] The platinum group metal can include at least one of platinum, palladium, rhodium, iridium, ruthenium, and osmium.
[0017] The decontamination chamber can be configured to generate reaction by-products such as CO as described above, but these can be treated using a catalyst for CO. Examples of such catalysts include, for example, hopcalite (copper manganese spinel), lanthanum copper oxide, and at least one of the noble metals on a support as described above.
[0018] The catalyst material for at least one of the direct decomposition of N2O and the oxidation of CO can include hopcalite (copper manganese spinel); lanthanum copper oxide; conventional supports such as alumina, silica, titania, and / or zeolite supports such as ZSM5, BEA, ferrierite, mordenite, etc., impregnated with at least one of iron, cobalt, nickel, manganese, palladium, platinum, indium, and / or silver, and a copper, zinc, and / or aluminum composite catalyst containing an alkali metal and / or an alkaline earth metal can also be used.
[0019] NO x The catalyst material for directly reducing or decomposing NO can comprise at least one of noble metal catalysts on carrier materials such as Cu-ZSM5, alumina and / or silica, and / or organometallic framework type catalysts.
[0020] The catalyst material for oxidizing at least one of CO and hydrocarbons comprises silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on another carrier comprising at least one of a suitable zeolite carrier and / or other carriers of silicon, zirconium, aluminum and / or titanium-based oxides; a zeolite carrier such as ZSM5, BEA, ferrierite and / or mordenite, which can be impregnated with metals such as cobalt, nickel, manganese, palladium, indium and / or silver; a material doped with oxides based on molybdenum, niobium and / or tungsten and further doped with an alkali, alkaline earth substance and / or barium; and comprises at least one of them.
[0021] It may be advantageous to operate the scrubbing chamber in the above manner so as to increase the concentration of reaction by-products such as CO or hydrocarbons. These by-products can react on the catalyst bed to produce CO2 and / or further react with NO on the catalyst bed to produce nitrogen. It has been recognized that the drawback of such catalyst technology is related to being operable even in the presence of various concentrations of combustion by-products such as water vapor, CO2, O2 generated from the scrubbed exhaust, and the presence of other compounds that may also be present in the original exhaust stream contained in the scrubbed exhaust stream. CO, hydrocarbons and / or NO x And further react with NO to produce nitrogen. It has been recognized that the drawback of such catalyst technology is related to being operable even in the presence of various concentrations of combustion by-products such as water vapor, CO2, O2 generated from the scrubbed exhaust, and the presence of other compounds that may also be present in the original exhaust stream contained in the scrubbed exhaust stream. CO, hydrocarbons and / or NO xExamples of suitable catalysts for this include at least one of silver, platinum, palladium, rhodium, iridium, ruthenium, and / or osmium on a suitable zeolite support or on another support containing at least one of silicon, zirconium, aluminum, or titanium-based oxides. Alternatively, catalysts containing zeolite supports such as ZSM5, BEA, ferrielite, or mordenite may be used, and such zeolite supports may be impregnated with metals such as cobalt, nickel, iron, manganese, palladium, indium, or silver. Furthermore, catalyst materials can be doped with molybdenum, niobium, or tungsten-based oxides, and can also be further doped with alkali metals or alkaline earth metals.
[0022] The catalyst bed may contain multiple catalyst materials.
[0023] A catalytic material for oxidizing CO and at least one hydrocarbon (reducing their concentrations) can be positioned either upstream or downstream of the catalytic material for directly decomposing N2O. The catalytic material for reducing CO and / or hydrocarbon concentrations typically needs to operate at a lower temperature than the catalytic material for N2O decomposition. By positioning one downstream of the other, this helps ensure that any exothermic reaction caused by the upstream catalytic material ensures heating of the downstream catalytic material. In some embodiments, the hydrocarbon / CO catalyst is placed before the N2O catalyst, because otherwise the N2O catalyst would... x This is because it may consume CO or hydrocarbons necessary to promote the reduction or decomposition of NO. x In the presence of NO, N2O may be produced, which will be removed by a downstream N2O catalyst. x This reduces the chance of being poisoned, NO xis removed by a catalyst placed upstream by reaction with hydrocarbons and / or CO. In other embodiments, it is preferred to position the N2O catalyst upstream of the hydrocarbon catalyst, and N2O has been made to not consume combustion by-products and / or hydrocarbons; otherwise, this would result in further treatment of NO x on the downstream catalyst bed.
[0024] The scavenging chamber can be configured to increase the concentration of at least one of at least one combustion by-product and at least one hydrocarbon, causing an increase in the exothermic catalytic reaction to raise the operating temperature of the catalyst bed. Thus, the temperature of the catalytic reaction can be controlled simply by changing the scavenging conditions in the scavenging chamber, and no separate heating device is required to heat the catalyst bed.
[0025] The scavenging chamber can be configured to increase the concentration of at least one of CO and hydrocarbons, causing an increase in the exothermic catalytic reaction to raise the operating temperature of the catalyst bed.
[0026] The scavenging chamber can be configured to temporarily increase the concentration of at least one of at least one combustion by-product and at least one hydrocarbon, causing an increase in the exothermic catalytic reaction to raise the operating temperature of the catalyst bed.
[0027] The scavenging chamber can be configured to order the increase in the concentration of at least one of a plurality of combustion by-products and a plurality of hydrocarbons, causing an increase in the rate of a series of exothermic catalytic reactions.
[0028] The scavenging chamber can be configured to order the increase in the concentration of one or more of CO, then hydrocarbons, then N2O, causing an increase in the rate of a series of exothermic catalytic reactions.
[0029] The catalyst bed can include a heat exchanger configured to preheat the exhaust stream before it is supplied to the scavenging chamber. Preheating the exhaust stream helps to recycle heat and reduce the overall energy consumption of the scavenging device.
[0030] A second embodiment provides a method for detoxifying an exhaust stream from a semiconductor processing tool, the method comprising: receiving the exhaust stream, detoxifying the exhaust stream in a detoxification chamber, and supplying the detoxified exhaust stream; receiving the detoxified exhaust stream, cleaning the detoxified exhaust stream in a wet scrubber, and supplying the cleaned exhaust stream as a cleaned exhaust stream; and receiving the cleaned exhaust stream, treating the cleaned exhaust stream in a catalyst bed located downstream of the wet scrubber, and supplying the treated exhaust stream.
[0031] The method may include the steps of controlling a detoxification chamber to supply a detoxified exhaust stream containing at least one of at least one combustion by-product and at least one hydrocarbon, and configuring a catalyst bed to reduce the concentration of at least one of the at least one combustion by-product and at least one hydrocarbon present in the treated exhaust stream.
[0032] The method may include the steps of controlling a detoxification chamber to supply a detoxified exhaust stream containing at least one of at least one combustion by-product and at least one hydrocarbon at a concentration above a threshold, and configuring a catalyst bed to reduce the concentration of at least one of at least one combustion by-product and at least one hydrocarbon present in the treated exhaust stream to below a threshold.
[0033] The method may include the step of controlling the detoxification chamber to supply at least one of at least one combustion byproduct and at least one hydrocarbon to the detoxified exhaust stream at a concentration higher than a threshold, at a temperature lower than that at which at least one of at least one combustion byproduct and at least one hydrocarbon is supplied to the detoxified exhaust stream at a concentration lower than a threshold.
[0034] The method may include the steps of: controlling a detoxification chamber to supply the detoxified exhaust stream with at least one of a plurality of combustion by-products and a plurality of hydrocarbons at their respective initial concentrations; and configuring a catalyst bed to carry out a plurality of catalytic reactions on the washed exhaust stream and to supply the treated exhaust stream with at least one of the plurality of combustion by-products and a plurality of hydrocarbons at concentrations lower than their respective initial concentrations.
[0035] The catalyst bed is used for the direct decomposition of N2O and NO X It may include at least one catalytic material for the reduction or decomposition of and at least one of the oxidation of CO and at least one hydrocarbon.
[0036] The catalyst bed may include a catalyst material comprising at least one of a metal oxide material, a metal oxide, and a noble metal on a support.
[0037] The support may include at least one of titanium, aluminum, zirconium, and silicon-based oxides. Examples of such materials include silica, silicalite, aluminosilicate titanium oxide, zirconia, alumina, and zeolite.
[0038] A precious metal may contain at least one platinum group metal.
[0039] Platinum group metals may include at least one of platinum, palladium, rhodium, iridium, ruthenium, and osmium.
[0040] As described above, the detoxification chamber can be configured to produce reaction byproducts such as CO, which can be treated using a catalyst for CO. Examples of such catalysts include, for example, hopkalite (copper manganese spinel), copper lanthanum oxide, or at least one of the noble metals on the aforementioned support.
[0041] The catalyst material for at least one of the direct decomposition of N2O and the oxidation of CO may include at least one of iron, cobalt, nickel, manganese, palladium, platinum, indium, or silver impregnated into conventional supports such as hopkalite (copper manganese spinel); lanthanum copper oxide; alumina, silica, titania, etc., or zeolite supports such as ZSM5, BEA, ferrielite, mordenite, etc. A composite catalyst of copper, zinc, and aluminum containing alkali metals or alkaline earth metals can also be used.
[0042] Catalyst materials for directly reducing or decomposing NOx may include at least one of the following: a noble metal catalyst on a support material such as Cu-ZSM5, alumina, or silica, or an organometallic structure catalyst.
[0043] A catalytic material for oxidizing CO and at least one hydrocarbon comprises at least one of the following: silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable zeolite support and / or other support containing at least one silicon, zirconium, aluminum and / or titanium-based oxide; a zeolite support such as ZSM5, BEA, ferrielite and / or mordenite, on which metals such as cobalt, nickel, manganese, palladium, indium and / or silver can be impregnated; and a material doped with molybdenum, niobium and / or tungsten-based oxides and further doped with alkali, alkaline earth substances and / or barium.
[0044] In some cases, it may be advantageous to operate the detoxification chamber in the manner described above to increase the concentration of reaction by-products such as CO or hydrocarbons. These by-products react on the catalyst bed to produce CO2 and / or NO on the catalyst bed. xIt can further react with to produce nitrogen. It is recognized that a drawback of such catalytic technologies is related to the varying concentrations of combustion byproducts such as water vapor, CO2, and O2 resulting from the washed exhaust, as well as the presence of other compounds that may also be present in the original exhaust and contained within the washed exhaust stream, including CO, hydrocarbons, and / or NO. x Examples of suitable catalysts for this include at least one of silver, platinum, palladium, rhodium, iridium, ruthenium, and / or osmium on a suitable zeolite support or on another support containing at least one of silicon, zirconium, aluminum, or titanium-based oxides. Alternatively, catalysts containing zeolite supports such as ZSM5, BEA, ferrielite, and / or mordenite may be used, and such zeolite supports can be impregnated with metals such as cobalt, nickel, iron, manganese, palladium, indium, and / or silver. Furthermore, catalyst materials can be doped with molybdenum, niobium, and / or tungsten-based oxides, and can also be doped with alkali metals and / or alkaline earth metals.
[0045] The catalyst bed may contain multiple catalyst materials.
[0046] The method may include the step of configuring a catalyst bed such that a catalyst material for reducing CO and at least one hydrocarbon is located either upstream or downstream of a catalyst material for directly decomposing N2O.
[0047] Catalyst materials for the oxidation or decomposition of CO and / or hydrocarbons typically need to operate at lower temperatures than catalyst materials for the decomposition of N2O. By positioning one downstream of the other, this helps ensure that the exothermic reaction caused by the upstream catalyst material ensures heating of the downstream catalyst material. In some embodiments, the hydrocarbon / CO catalyst is placed before the N2O catalyst, because otherwise the N2O catalyst would not be able to decompose NO xThis is because it may consume CO or hydrocarbons necessary to promote the reduction or decomposition of NO. x In the presence of NO, N2O may be produced, which will be removed by a downstream N2O catalyst. This is because the N2O catalyst will then remove NO. x This reduces the chance of being poisoned, NO x These are removed by a catalyst placed before them through reaction with hydrocarbons and / or CO. In other embodiments, it is preferable to position the N2O catalyst upstream of the hydrocarbon catalyst so that the N2O does not consume combustion byproducts and / or hydrocarbons, otherwise it would consume NO on the downstream catalyst bed. x This will lead to further measures.
[0048] The method may include a step of controlling the detoxification chamber to increase the concentration of at least one of at least one combustion by-product and at least one hydrocarbon, thereby causing an increase in the exothermic catalytic reaction that raises the operating temperature of the catalyst bed.
[0049] This method may include the step of controlling the detoxification chamber to increase the concentration of at least one of CO and hydrocarbons, thereby increasing the exothermic catalytic reaction and raising the operating temperature of the catalyst bed.
[0050] This method may include a step of controlling the detoxification chamber to temporarily increase the concentration of at least one of at least one combustion by-product and at least one hydrocarbon, thereby causing an increase in the exothermic catalytic reaction and raising the operating temperature of the catalyst bed.
[0051] This method may include a step of controlling a detoxification chamber to sequence the increase in the concentration of at least one of several combustion by-products and several hydrocarbons, thereby causing an increase in the rate of a series of exothermic catalytic reactions.
[0052] This method may include a step of controlling a detoxification chamber to sequentially increase the concentration of one or more of the following: CO, then hydrocarbons, then N2O, in order to increase the rate of a series of exothermic catalytic reactions.
[0053] This method may include the steps of installing a heat exchanger in the catalyst bed and preheating the exhaust flow using the heat exchanger before supplying it to the abatement chamber.
[0054] Further specific preferred embodiments are described in the attached independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as appropriate and in combinations other than those expressly described in the claims.
[0055] When a feature of a device is described as being capable of operating to produce a certain function, it should be understood that this includes features of the device that produce that function, or that are adapted or configured to produce that function.
[0056] Herein, embodiments of the present invention will be further described with reference to the accompanying drawings. [Brief explanation of the drawing]
[0057] [Figure 1] A schematic diagram of a pollution control device according to one embodiment is shown. [Figure 2A] The catalytic bed configuration is shown in general terms. [Figure 2B] The catalytic bed configuration is shown in general terms. [Figure 2C] The catalytic bed configuration is shown in general terms. [Figure 2D] The catalytic bed configuration is shown in general terms. [Figure 2E] The catalytic bed configuration is shown in general terms. [Figure 2F] The catalytic bed configuration is shown in general terms. [Figure 2G] The catalytic bed configuration is shown in general terms. [Modes for carrying out the invention]
[0058] Before describing the embodiments in more detail, an overview will be provided. Several embodiments provide configurations for detoxifying compounds in exhaust streams from, for example, semiconductor processing tools. A detoxification chamber receives the exhaust stream to be detoxified, performs detoxification, and supplies the detoxified exhaust stream to a scrubber configuration, which washes the detoxified exhaust stream and supplies the washed exhaust stream. The washed exhaust stream is supplied to a catalyst bed. The washed exhaust stream undergoes a catalytic reaction with the catalyst in the catalyst bed and supplies the treated exhaust stream. This allows the detoxification system to detoxify, remove, reduce the concentration of, decompose, or treat compounds present in the exhaust stream before the exhaust stream is typically discharged into the atmosphere. The configuration of a detoxification chamber in combination with a catalyst bed allows compounds that would normally be problematic and energy-intensive to detoxify by the detoxification chamber to be treated, decomposed, or reacted with more suitable compounds using the catalyst bed instead. This allows the detoxification chamber to operate at lower temperatures, reducing stress on the detoxification chamber, as well as reducing the energy consumption of the detoxification system, and providing improved detoxification of some compounds. In some embodiments, a combination of catalyst materials can be provided within the catalyst bed to assist in the treatment of different compounds or groups of compounds in the exhaust flow. Furthermore, since the reactivity of some catalysts may be temperature-dependent, a control device can be used to control the operation of the abatement chamber to cause some of the catalysts in the catalyst bed to undergo an exothermic reaction in order to increase the heat near the catalyst and achieve the desired reactivity, thereby eliminating the need for an electric heater to supply the heat. Additionally, in some embodiments, the catalyst bed functions as a heat exchanger to help preheat the incoming exhaust flow.
[0059] In some embodiments, different catalysts and different combinations of catalysts are provided to assist in different types of reactions for treating compounds flowing over a catalyst bed. It is recognized that the drawbacks of certain catalyst technologies relate to their ability to operate in the presence of various concentrations of combustion byproducts such as water vapor, CO2, and O2 resulting from the washed effluent, as well as other compounds in the washed effluent that may also be present in the original effluent.
[0060] In some embodiments, catalysts are provided that treat only CO. However, NO x The catalyst provided for treating both +CO catalysts, and the catalyst provided for treating N2O catalysts, are NO x It should be understood that it can also be used for CO in the absence of N2O. A catalyst containing one or more hopkalite (copper manganese spinel) and / or lanthanum copper oxide can be used to treat CO only. A catalyst having some noble metal such as platinum, palladium, rhodium, iridium, ruthenium and / or osmium can be used on a suitable zeolite support and / or other support having at least one of silicon, zirconium, aluminum or titanium. Gold on a support such as ceria oxide can also be used for this purpose.
[0061] In some embodiments, catalysts are provided for treating NO (i.e., removing NO without any additional reducing agent). Such catalysts include one or more of the following, exhibiting NO-reducing activity: catalysts such as Cu-ZSM5, catalysts such as noble metal catalysts on a support material such as alumina and / or silica, or organometallic structure catalysts.
[0062] In some embodiments, catalysts are provided for treating NO+CO (i.e., removing NO with CO as a reducing agent). It should be understood that this may produce some N2O and therefore require an N2O catalyst behind it. More specifically, catalysts for treating NO+CO in the presence of water and oxygen comprise one or more catalysts containing some noble metal such as platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable support. Suitable supports include various zeolites such as ZSM5 and BEA zeolites, and / or those containing silicon, zirconium, aluminum and / or titanium-based oxides thereon. The catalyst material may also be doped with molybdenum, niobium, barium and / or tungsten-based oxides and / or further doped with alkali and / or alkaline earth substances.
[0063] In some embodiments, catalysts for treating N2O are provided. Such catalysts include one or more of the following: catalysts comprising a zeolite support such as ZSM5, BEA, ferrielite, or mordenite, and / or catalysts having a conventional support such as alumina, titania, and / or silica. Such supports can be impregnated with metals such as iron, cobalt, nickel, manganese, palladium, indium, and / or silver. Hopkalite (copper-manganese spinel) can be used for this purpose, and composite catalysts of copper, zinc, and aluminum containing alkali metals and / or alkaline earth metals can also be used.
[0064] In some embodiments, catalysts for treating NO+ hydrocarbons are provided (or, if used to adjust the reactor temperature, catalysts for treating hydrocarbons only are provided). Such catalysts comprise one or more catalysts having zeolite supports such as ZSM5, BEA, ferrielite, and / or mordenite. Metals such as cobalt, nickel, manganese, palladium, indium, and / or silver can be impregnated into such zeolite supports, or additionally into other aluminum, zirconium, silicon, and titanium oxide-based supports. Precious metals such as palladium on suitable supports such as sulfated zirconia or titania can be used for this purpose.
[0065] Abatement device Figure 1 schematically shows a pollution control device 10 according to one embodiment. The pollution control device 10 has a pollution control chamber 20 coupled with a downstream scrubber 30. In this embodiment, the scrubber 30 comprises a weir and spray nozzle structure 40, a downstream sump 50, and a downstream composite packed column and wet electrolytic dust collector 60. A catalyst bed 70 is located downstream of the composite packed column and wet electrolytic dust collector 60.
[0066] Generally, the discharge flow 80 (along with the necessary combustion reagents) enters the detoxification chamber 20, where the compounds in the discharge flow 80 are detoxified, producing a detoxified discharge flow 85. The detoxified discharge flow 85 flows into a downstream weir and spray nozzle structure 40, where it is cooled by the weir and larger particulate matter is removed by the spray produced by the spray nozzles, and then flows into the sump 50. The detoxified discharge flow 85 then flows upward through a composite packed tower and wet electrolytic dust collector 60, which further captures particulate matter in the detoxified discharge flow 85 and helps remove soluble compounds from within the detoxified discharge flow 85. The detoxified discharge flow 85 then continues to flow over a downstream catalyst bed 70, where one or more catalytic reactions occur between the compounds in the detoxified discharge flow 85, which is intended to treat, decompose, or remove those compounds from the detoxified discharge flow before the treated discharge flow 87 is typically discharged into the atmosphere.
[0067] As will be explained in more detail below, the control device 90 can control the conditions in the abatement chamber 20 to change the concentration of compounds flowing out of the abatement chamber in the abated exhaust flow 85 in order to induce one or more exothermic reactions occurring in the catalyst bed 70, in order to adjust the reactivity of one or more catalysts in the catalyst bed 70. This method eliminates the need to provide a heating element in the catalyst bed 70 to control the reactivity of the catalyst bed 70.
[0068] Furthermore, as shown in Figure 1, the catalyst bed 70 can be provided as part of the heat exchanger 75 to help preheat the exhaust flow 80 before it is introduced into the abatement chamber 20. This results in some heat recovery, which helps reduce the energy consumption of the abatement device 10.
[0069] The discharge stream may contain several different compounds depending on the operation of the upstream semiconductor processing tool. For example, the discharge stream may contain N2O, SiH4, NH3, and NF3 at various times and at various concentrations or amounts. Depending on the conditions inside the detoxification chamber, various different compounds may emerge from the detoxification chamber 20 into the detoxified discharge stream 85. For example, N2O may be present in the detoxified discharge stream. X Some residual N2O, and possibly N2, may also be produced. Similarly, SiH4 may become SiO2 in the detoxified effluent. NH3 may become NO in the detoxified effluent. X It can become CH4, CO2, and CO. NF3 is NO in the decontaminated discharge stream. Xand HF may occur. The presence of N2O, NO, NO2 and / or CO in the purified exhaust stream is undesirable, and typically, environmental and / or safety regulations require that the gas stream released from the purifying device 10 has concentrations or parts per million levels below certain thresholds for these compounds. However, optimizing the purifying chamber 20 to achieve these thresholds is difficult and typically requires very high energy consumption. However, the catalyst bed 70 contains one or more catalysts optimized to assist catalytic reactions that treat, purify, or decompose these compounds into safer compounds such as carbon dioxide, nitrogen, and oxygen.
[0070] Figures 2A-2G schematically show various configurations of catalyst beds 70A-70G according to embodiments. The catalyst beds 70A-70G are provided with appropriate physical configurations to ensure that sufficient surface area is provided to facilitate the required reaction. The configuration can also be provided as part of a heat exchanger 75.
[0071] Figure 2A shows the configuration in which excess CO and O2 in the decontaminated exhaust flow 85 are remediated. In this example, the catalyst bed 70A contains catalyst A. Catalyst A causes CO2 to be generated from CO and O2.
[0072] Figure 2B shows the configuration when excess CO, O2, NO, and NO2 in the detoxified exhaust flow 85 are treated. In this example, the catalyst bed 70B includes catalyst A and catalyst B. Catalyst A operates as described above, while catalyst B causes N2 and O2 to be generated from NO and NO2.
[0073] Figure 2C shows the configuration when excess CO and / or hydrocarbons, O2, NO, and NO2 in the detoxified exhaust flow 85 are treated. In this example, the catalyst bed 70C contains a single catalyst C. Catalyst C causes CO2 to be produced from CO and / or hydrocarbons and O2, and similarly causes N2 and O2 to be produced from NO and NO2. This catalyst can also be used to treat only hydrocarbons or only CO, which are used to supply heat to raise the catalyst temperature.
[0074] Figure 2D shows the configuration when excess N2O in the detoxified exhaust flow 85 is treated. In this example, the catalyst bed 70D contains catalyst D. Catalyst D causes N2 and O2 to be generated from N2O.
[0075] Figure 2E shows the arrangement when excess N2O, NO, and NO2 in the detoxified exhaust flow 85 are treated. In this example, the catalyst bed 70E includes catalysts B and D, each operating as described above.
[0076] Figure 2F shows the arrangement when excess CO, O2, N2O, NO, and NO2 in the detoxified exhaust flow 85 are treated. In this example, the catalyst bed 70F includes catalysts A, B, and D, each operating as described above.
[0077] Figure 2G shows the configuration when excess CO, O2, N2O, NO, and NO2 in the detoxified exhaust stream 85 are treated. In this example, the catalyst bed 70G includes catalysts C and D, each operating as described above. In this configuration, catalyst C can be placed before catalyst D, because otherwise catalyst D might consume CO or be poisoned by NO. In addition, catalyst C may produce N2O, which is then removed by catalyst D. Alternatively, catalyst D can be placed before catalyst C to prevent N2O from causing a competing reaction with the hydrocarbon / CO reaction occurring on catalyst C. In this case, catalyst D also supplies heat to aid the reaction on catalyst C.
[0078] Some examples of CO oxidation catalyst A include one or more of hopkalite (spinel-type copper-manganese) or lanthanum copper oxide, which can be used for CO oxidation in the presence of oxygen. Catalysts containing some noble metal such as silver, platinum, palladium, rhodium, iridium, ruthenium, and / or osmium on a suitable zeolite support or other support containing at least one of silicon, aluminum, and / or titanium can be used. Catalysts such as gold on cerium oxide can also be used for this purpose.
[0079] NO X Some examples of catalyst B for the decomposition or reduction of NO include catalysts such as Cu-ZSM5 that exhibit NO reduction activity, and / or noble metal catalysts on a support material such as alumina and / or silica, and / or organometallic structure type catalysts, comprising one or more of these.
[0080] Some examples of catalyst C for reacting NO with CO and / or hydrocarbons include one or more of silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable zeolite support and / or other support containing at least one of silicon, zirconium, aluminum and titanium-based oxides. Alternatively, catalysts containing zeolite supports such as ZSM5, BEA, ferrielite and / or mordenite can be used, in which case such zeolite supports can be impregnated with metals such as cobalt, nickel, manganese, palladium, indium and / or silver. Furthermore, catalyst materials can be doped with molybdenum, niobium and / or tungsten-based oxides and / or further doped with alkalis, alkaline earth substances and / or barium.
[0081] Some examples of catalyst D for the direct decomposition of N2O include one or more of the following: hopkalite (spinel-type copper-manganese); lanthanum copper oxide; iron, cobalt, nickel, manganese, palladium, platinum, indium, and / or silver impregnated into conventional carriers such as alumina, silica, and / or titania, or into zeolite carriers such as ZSM5, BEA, ferrielite, and / or mordenite; and copper, zinc, and aluminum composite catalysts also containing alkalis and / or alkaline earth metals. In some embodiments, the NO+CO catalyst is placed before the N2O catalyst because otherwise the N2O catalyst may consume CO or be poisoned by NO.
[0082] Therefore, it can be seen that some embodiments provide apparatus for detoxifying N2O, NO, NO2 and CO, including burner-washers and catalysts, and methods for operating the apparatus. As mentioned above, some semiconductor processes use N2O, a powerful greenhouse gas. Combustion detoxification of N2O can result in conversion to NO and to some extent to NO2, both of which are harmful to human health and the environment. In addition, the combustible detoxification of other nitrogen-containing gases such as NH3 or NF3 results in NO x This could lead to the generation of NO. x CO formation can be limited by adjusting the combustor conditions (fuel-oxidizer ratio), but this generally leads to large CO formation.
[0083] Some embodiments provide a burner-scrubber with a catalyst bed downstream for the detoxification of N2O, NO, NO2, and / or CO. Ideally, the burner conditions are optimized for the detoxification of harmful substances other than N2O, and ideally, N2O should pass through the burner undetoxified. A downstream wet scrubber may seem counterintuitive, but it helps remove acidic gases and particulate matter to protect the catalyst. The wet scrubber may further be equipped with a wet electrolytic dust collector. The catalyst can be one or more of a variety of materials with demonstrable detoxification performance against N2O, NO, NO2, and / or CO. Hopkalyte, a mixture of manganese oxide and copper oxide, is an unexpected but useful option. Various grades with different detailed compositions are available and optimized for one or more specific applications. The advantage of using hopkalyte is that it oxidizes CO at room temperature and hydrocarbons at moderately high temperatures. Temperatures above 400°C are required for the detoxification of N2O. Therefore, the catalyst can be heated by intentionally operating the burner under rich conditions (leading to CO generation). By adjusting the detoxification to also release CO, NO X This leads to a reduction in emissions, and the hopkalyte catalyst plays a role in reducing CO in the final emissions, which in turn removes high N2O concentrations resulting from modified burner conditions. Further synergies are also evident if heating can be achieved by passing the fuel gas (such as methane) through the catalyst. If a heat exchanger is included, the off-gas from the catalyst can be used to preheat the exhaust flow. Since the destruction of N2O on the catalyst is exothermic, the heat generated can offset losses from the system. If the temperature falls below a predetermined value, the burner can be adjusted to increase the emission of CO and / or hydrocarbons, or a valve can be opened to allow a controlled flow of fuel on the catalyst. The catalytic reactor may also be equipped with an electric heater. In certain gas combinations within the exhaust flow, the exhaust flow from the filtration chamber will have NO levels above the environmental threshold. X It may contain NO. In this case, NO may be present with the help of a hydrocarbon catalyst. XIt is desirable to remove NO. In addition, the oxygen level in the exhaust changes depending on the burner conditions, X It is understood that hydrocarbons and / or CO may be preferentially consumed over reactions with . For example, in other catalysts in which iridium is supported on a carrier such as silica and optionally doped with metals such as tungsten and barium, it is advantageous to allow CO to flow over the catalyst in the absence of oxygen and / or water during the detoxification of NO and NO2 to function as a reducing agent. In other embodiments, it may be preferable to use ferrielites optionally doped with, for example, platinum group metals and / or indium, such as cobalt ferrielite, which oxidizes methane to NO x Removal and reactor heating can be performed simultaneously, along with N2O removal. The catalyst bed can contain up to three separate catalysts, one optimized for the direct decomposition of N2O, another for the reduction of NO and NO2, and a third for the oxidation of CO and hydrocarbons. A particular set of catalysts may be selected in this way because it can be arranged in a specific synergistic effect. For example, historically, a problem associated with platinum group metal catalysts such as the iridium or platinum catalysts mentioned above is the generation of N2O as a byproduct. However, by utilizing these platinum group metal catalysts, which are poor at methane conversion, and placing the iridium catalyst before the cobalt ferrielite catalyst, both N2O and NO removal can be successfully achieved.
[0084] While exemplary embodiments of the present invention have been disclosed in detail with reference to the accompanying drawings, it will be understood that the present invention is not limited to the exact embodiments and that various changes and modifications can be made by those skilled in the art without departing from the scope of the invention as defined by the accompanying claims and their equivalents. [Explanation of Symbols]
[0085] 10 Abatement equipment 20 Abatement room 30 Scrubber 40. Weir and spray nozzle structure 50 Sump 60. Composite packed tower and wet electrolytic dust precipitator 70, 70A-G catalyst bed 75 Heat exchanger 80 Discharge stream 85 Decontaminated discharge 87 Treated discharge flow 90 Control device
Claims
1. A decontamination device for decontaminating the discharge flow from semiconductor processing tools, A detoxification chamber configured to receive the aforementioned discharge flow and supply the discharge flow that has been detoxified by combustion, A wet scrubber is located downstream of the abatement chamber and is configured to receive the abated discharge flow and supply the discharge flow that has been washed with liquid, A catalyst bed is located downstream of the wet scrubber and is configured to receive the washed discharge flow and supply the discharge flow treated by the catalytic reaction, Equipped with, The aforementioned detoxification chamber supplies the detoxified discharge flow to the aforementioned wet scrubber. The detoxification chamber supplies at least one combustion by-product and at least one hydrocarbon to the detoxified exhaust stream at a concentration higher than the threshold amount, at a temperature lower than the temperature at which at least one combustion by-product and at least one hydrocarbon are supplied to the detoxified exhaust stream at a concentration lower than the threshold amount. The detoxification chamber is configured to operate at a temperature lower than the temperature normally required to supply the combustion by-products and / or hydrocarbons at a concentration lower than the threshold amount. The catalyst bed is The system is configured to reduce the concentration of at least one of the at least one combustion by-product and at least one of the at least one hydrocarbon present in the treated exhaust stream to below an environmentally acceptable threshold level. Furthermore, the catalyst bed is Direct decomposition of nitrous oxide (N₂O), At least one of direct reduction and decomposition of nitrogen oxides (NOx), and Carbon monoxide (CO) and at least one hydrocarbon oxidation, A detoxification device comprising at least one catalytic material for performing at least one of the following.
2. The abatement apparatus according to claim 1, wherein the catalyst bed comprises a catalyst material comprising at least one of a metal oxide material and a noble metal on a carrier.
3. N 2 The catalyst material for the direct decomposition of O and the oxidation of CO is Hopkalite (copper manganese spinel) and Lanthanum copper oxide and A carrier comprising at least one of alumina, silica, and / or titania, and / or a zeolite carrier comprising at least one of ZSM5, BEA, ferrielite, and / or mordenite, impregnated with iron, cobalt, nickel, manganese, palladium, platinum, indium, and / or silver, A copper, zinc, and / or aluminum composite catalyst containing alkali metals and / or alkaline earth metals, The pollution control device according to claim 1, comprising at least one of the following.
4. NO X The catalyst material for reduction or decomposition of is Cu-ZSM5 and, A noble metal catalyst and / or organometallic structure type catalyst on a support material containing at least one alumina and / or silica, A pollution control device according to claim 1 or 3, comprising at least one of the following.
5. The catalyst material for oxidizing at least one of CO and hydrocarbons is Silver, platinum, palladium, rhodium, iridium and / or ruthenium on a suitable zeolite support and / or on another support containing at least one of silicon, zirconium, aluminum and / or titanium-based oxides, A zeolite carrier comprising at least one of ZSM5, BEA, ferrielite and / or mordenite, which can be impregnated with a metal containing at least one of cobalt, nickel, manganese, palladium, indium, or silver, Materials doped with molybdenum, niobium, and / or tungsten-based oxides, and further doped with alkali, alkaline earth substances, and / or barium, The pollution control device according to claim 1, comprising at least one of the following.
6. The abatement apparatus according to claim 1, wherein the catalyst bed comprises a plurality of catalyst materials.
7. The catalyst material for oxidizing at least one of CO and hydrocarbons is N 2 The abatement device according to claim 1, wherein the device is positioned upstream or downstream of the catalyst material for directly decomposing oxygen.
8. The abatement room is To increase the concentration of at least one of at least one combustion by-product and at least one hydrocarbon, thereby increasing the exothermic catalytic reaction and raising the operating temperature of the catalyst bed, Increasing the concentration of at least one of CO and / or hydrocarbons to cause an increase in the exothermic catalytic reaction and raise the operating temperature of the catalyst bed, The abatement device according to claim 1, configured to perform at least one of the following.
9. The abatement apparatus according to claim 1, wherein the abatement chamber is configured to temporarily increase the concentration of at least one of the at least one combustion by-product and at least one hydrocarbon, thereby causing the increase in the exothermic catalytic reaction and raising the operating temperature of the catalyst bed.
10. The abatement apparatus according to claim 1, wherein the abatement chamber is configured to increase the rate of a series of exothermic catalytic reactions by sequentially increasing the concentration of at least one of a plurality of combustion by-products and a plurality of hydrocarbons.
11. The aforementioned detoxification chamber contains CO, hydrocarbons, and N₂O in that order. 2 The abatement device according to claim 10, configured to increase the concentration of one or more of the oxygen atoms to cause the aforementioned increase in the rate of the series of exothermic catalytic reactions.
12. The abatement apparatus according to claim 1, wherein the catalyst bed comprises a heat exchanger configured to preheat the exhaust flow before it is supplied to the abatement chamber.