Pest control device and method

Abstract

An abatement apparatus and method are disclosed. The abatement apparatus is for abating an exhaust stream from a semiconductor processing tool and includes an abatement chamber configured to receive the exhaust stream and provide an abatement exhaust stream, a wet scrubber positioned downstream of the abatement chamber and configured to receive the abatement exhaust stream and provide a scrubbed exhaust stream, and a catalyst bed positioned downstream of the wet scrubber and configured to receive the scrubbed exhaust stream and provide a treated exhaust stream. In this manner, undesirable compounds present in the abatement exhaust stream because they were already present in the exhaust stream or were not sufficiently abated by the abatement chamber, or because they are abatement by-products generated in the abatement chamber, can be treated, removed, or reduced by the catalyst bed before being released by the abatement apparatus. This helps to improve the performance of the abatement apparatus by removing compounds that may otherwise be difficult or energy intensive to remove using only the abatement chamber.

Description

[Technical field]

[0001] The field of the invention relates to abatement devices and methods. [Background technology]

[0002] Abatement devices for performing abatement are known and are typically used to treat exhaust gas streams from manufacturing process tools used, for example, in the semiconductor or flat panel display manufacturing industries. During such manufacturing, residual perfluorinated compounds (PFCs) and other compounds are present in the exhaust gas streams pumped from the process tools. PFCs are difficult to remove from the 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 the exhaust gas stream. Such other compounds may include, but are not limited to, silane (SiH4), nitrogen oxides (N2O), or NF3. Typically, the exhaust gas stream is a nitrogen stream containing the process gases described above. Often, a fuel gas is mixed with the exhaust gas stream and the gas stream mixture is conveyed into a combustion chamber laterally surrounded by an exit face of a perforated gas burner. Fuel gas and air are simultaneously supplied to the perforated burner to affect flameless combustion at the exit face, and the amount of air passing through the perforated burner is required to be sufficient to consume all combustibles in the gas stream mixture injected into the combustion chamber, as well as to supply fuel gas to the burner. Electrically heated and plasma abatement devices are also known and operate in a similar manner. Summary of the Invention [Problem to be solved by the invention]

[0004] Although techniques exist for treating exhaust gas streams, each has its own drawbacks. It would therefore be desirable to provide improved techniques for treating exhaust gas streams. [Means for solving the problem]

[0005] According to a first aspect, an abatement apparatus for abating an exhaust stream from a semiconductor processing tool is provided, the abatement apparatus comprising: an abatement chamber configured to receive the exhaust stream and provide an abatemented exhaust stream; a wet scrubber positioned downstream of the abatement chamber and configured to receive the abatemented exhaust stream and provide a scrubbed exhaust stream; and a catalyst bed positioned downstream of the wet scrubber and configured to receive the scrubbed exhaust stream and provide a treated exhaust stream.

[0006] The first aspect recognizes that a problem with existing systems is that it can be difficult to achieve the necessary conditions within the abatement chamber to abate the compounds and / or abatement by-products in the exhaust stream to a level that allows them to be discharged from the abatement system. Also, the composition of PFCs and other compounds may not be maintained at a constant level in the exhaust gas, which can pose an additional challenge to providing a well-treated exhaust stream.

[0007] Accordingly, an abatement apparatus is provided. The abatement apparatus may be for abating an exhaust stream. The exhaust stream may be from a semiconductor processing tool. The abatement apparatus may comprise an abatement chamber. The abatement chamber may be configured or arranged to receive the exhaust stream. The abatement chamber may be configured or arranged to abate the exhaust stream to provide an abatement exhaust stream. The abatement apparatus may comprise a wet scrubber. The wet scrubber may be located or positioned downstream of the abatement chamber. The wet scrubber may be configured or adapted to receive the abatement exhaust stream. The wet scrubber may scrub the abatement exhaust stream and provide the scrubbed exhaust stream. The abatement apparatus 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 arranged to receive the scrubbed exhaust stream. The catalyst bed may support catalytic reactions of the scrubbed exhaust stream to provide a treated exhaust stream. The treated effluent stream can have compounds removed from the scrubbed effluent stream by catalytic reaction with the catalyst bed. In this way, undesirable compounds present in the abatement effluent stream because they were already present in the effluent stream or were not fully abated by the abatement chamber, or because they are abatement by-products or abatement reactants generated in the abatement chamber, can be treated, removed, or have their concentration reduced by the catalyst bed before being released by the abatement system. This helps improve the performance of the abatement system by removing compounds that may otherwise be difficult or energy intensive to remove using only the abatement chamber.

[0008] The abatement chamber can be configured to provide an abatement exhaust stream that includes at least one of at least one combustion by-product and at least one hydrocarbon, and the catalyst bed can be configured to reduce a concentration of at least one of the at least one combustion by-product and at least one hydrocarbon present in the treated exhaust stream. Thus, the combustion or abatement by-products and / or hydrocarbons can be treated, removed, or have their concentrations reduced using the catalyst bed.

[0009] The abatement chamber can be configured to provide at least one of the at least one combustion by-product and the at least one hydrocarbon to the abated exhaust stream at a concentration above a threshold value, and the catalyst bed can be configured to reduce the concentration of the at least one combustion by-product and the at least one hydrocarbon present in the treated exhaust stream below a threshold value. Thus, the catalyst bed can reduce the concentration of the combustion by-product or hydrocarbon below a threshold value that is typically environmentally acceptable.

[0010] The abatement chamber can be configured to provide at least one of the at least one combustion by-product and at least one hydrocarbon to the abated exhaust stream at a concentration above the threshold value at a lower temperature than would be required to provide at least one of the at least one combustion by-product and at least one hydrocarbon to the abated exhaust stream at a concentration below the threshold value. Thus, the abatement chamber can be operated at a lower temperature than it would otherwise need to operate at to provide the combustion by-products and / or hydrocarbons at a concentration below the threshold value; in other words, the abatement chamber can be operated at a lower temperature, which would lead to a higher concentration of the combustion by-products or hydrocarbons, but which can be treated by the catalyst bed. This helps reduce the overall energy consumption of the abatement device.

[0011] The abatement chamber may be configured to provide at least one of the plurality of combustion by-products and the plurality of hydrocarbons to the abatement exhaust stream at an initial concentration of each, and the catalyst bed may be configured to perform a plurality of catalytic reactions on the scrubbed exhaust stream to provide at least one of the plurality of combustion by-products and the plurality of hydrocarbons to the treated exhaust stream at a concentration lower than the initial concentration of each. Thus, a plurality of different catalysts may be provided, each capable of performing a catalytic reaction on one or more associated combustion by-products and / or hydrocarbons to reduce their concentration.

[0012] The catalyst bed is used for the direct decomposition of NO,X and 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 precious metal on a support.

[0014] The support may comprise at least one of titanium, aluminum, zirconium and silicon based oxides, examples of which include silica, silicalite, aluminosilicate titanium oxide, zirconia, alumina and zeolites.

[0015] The precious metal can include at least one platinum group metal.

[0016] The platinum group metals can include at least one of platinum, palladium, rhodium, iridium, ruthenium, and osmium.

[0017] The abatement chamber can be configured to produce reaction by-products, such as CO, as described above, which 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 precious metals on a support as described above.

[0018] The catalytic materials for at least one of the direct decomposition of NO and oxidation of CO may include at least one of iron, cobalt, nickel, manganese, palladium, platinum, indium, and / or silver impregnated on hopcalite (copper manganese spinel); lanthanum copper oxide; conventional supports such as alumina, silica, titania, and / or zeolite supports such as ZSM5, BEA, ferrierite, mordenite, and / or copper, zinc, and / or aluminum composite catalysts containing alkali metals and / or alkaline earth metals may also be used.

[0019] NO x The catalytic material for the direct reduction or decomposition of can include at least one of Cu-ZSM5, a noble metal catalyst on a support material such as alumina and / or silica, and / or a metal-organic framework type catalyst.

[0020] The catalytic material for oxidizing at least one of CO and hydrocarbons comprises at least one of silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable zeolite support and / or other support comprising at least one of silicon, zirconium, aluminum and / or titanium based oxides; zeolite supports such as ZSM5, BEA, ferrierite and / or mordenite, where metals such as cobalt, nickel, manganese, palladium, indium and / or silver can be impregnated into such zeolite supports; and materials doped with molybdenum, niobium and / or tungsten based oxides and further doped with alkali, alkaline earth and / or barium.

[0021] It may be advantageous to operate the abatement chamber in the manner described above to increase the concentration of reaction by-products such as CO or hydrocarbons. These by-products may react on the catalyst bed to produce CO2 and / or react on the catalyst bed to produce NO2. x It has been recognized that the drawback of such catalytic technology is related to its ability to operate in the presence of various concentrations of combustion by-products such as water vapor, CO2, O2, etc., originating from the scrubbed exhaust, as well as other compounds that may also be present in the original exhaust stream, such as CO, hydrocarbons, and / or NO. xExamples of suitable catalysts for include at least one of silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable zeolite support or on other supports including at least one of silicon, zirconium, aluminum or titanium based oxides. Alternatively, catalysts including zeolite supports such as ZSM5, BEA, ferrierite or mordenite can be used, which can be impregnated with metals such as cobalt, nickel, iron, manganese, palladium, indium or silver. The catalytic material can also be doped with oxides based on molybdenum, niobium or tungsten, and can also be doped with alkali metals or alkaline earth metals.

[0022] The catalyst bed can include multiple catalyst materials.

[0023] The catalytic material for oxidizing (reducing the concentration of) at least one of CO and hydrocarbons can be located one upstream and one downstream of the catalytic material for directly decomposing NO. The catalytic material for reducing the concentration of CO and / or hydrocarbons typically needs to be operated at a lower temperature than the catalytic material for the decomposition of NO. By locating one downstream of the other, this helps ensure that any exothermic reaction caused by the upstream catalytic material heats up the downstream catalytic material. In some embodiments, the hydrocarbon / CO catalyst will be placed before the NO catalyst because the NO catalyst would otherwise not be able to oxidize the NO. x In addition, the hydrocarbon / CO catalyst may consume the CO or hydrocarbons required to promote the reduction or decomposition of NO. x In the presence of NO, N2O may be produced, which is removed by a downstream N2O catalyst. x Reduces the chance of contamination by NO xNO is removed on the preceding catalyst by reaction with hydrocarbons and / or CO. In another embodiment, it is preferred to position the NO catalyst upstream of the hydrocarbon catalyst so that NO does not consume combustion by-products and / or hydrocarbons that would otherwise be removed by NO on the downstream catalyst bed. x This will result in further treatment of the

[0024] The abatement chamber can be configured to increase the concentration of at least one of the at least one combustion by-product and the at least one hydrocarbon, causing an increase in the exothermic catalytic reaction to increase the operating temperature of the catalyst bed, such that the temperature of the catalytic reaction can be controlled simply by changing the abatement conditions in the abatement chamber, without the need for a separate heating device to heat the catalyst bed.

[0025] The abatement chamber may be configured to increase the concentration of at least one of CO and hydrocarbons, causing an increase in exothermic catalytic reactions to increase the operating temperature of the catalyst bed.

[0026] The abatement chamber can be configured to temporarily increase the concentration of at least one of the at least one combustion by-product and the at least one hydrocarbon to cause an increase in exothermic catalytic reactions to increase the operating temperature of the catalyst bed.

[0027] The abatement chamber may be configured to sequence an increase in the concentration of at least one of the plurality of combustion by-products and the plurality of hydrocarbons to cause an increase in the rate of a series of exothermic catalytic reactions.

[0028] The abatement chamber may be configured to sequence increasing concentrations 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 fed to the abatement chamber. Preheating the exhaust stream recycles heat and helps reduce the overall energy consumption of the abatement system.

[0030] According to a second aspect, there is provided a method of abating an exhaust stream from a semiconductor processing tool, the method comprising the steps of receiving the exhaust stream, abating the exhaust stream in an abatement chamber, and providing an abated exhaust stream; receiving the abated exhaust stream, scrubbing the abated exhaust stream in a wet scrubber, and providing the scrubbed exhaust stream as a scrubbed exhaust stream; receiving the scrubbed exhaust stream, and treating the scrubbed exhaust stream with a catalyst bed positioned downstream of the wet scrubber, and providing a treated exhaust stream.

[0031] The method may include controlling an abatement chamber to provide an abatement exhaust stream comprising at least one of the at least one combustion by-product and the at least one hydrocarbon, and configuring a catalyst bed to reduce a concentration of the at least one of the at least one combustion by-product and the at least one hydrocarbon present in the treated exhaust stream.

[0032] The method may include controlling the abatement chamber to provide an abated exhaust stream with at least one of the at least one combustion by-product and the at least one hydrocarbon present in the treated exhaust stream at a concentration greater than a threshold value, and configuring the catalyst bed to reduce a concentration of at least one of the at least one combustion by-product and the at least one hydrocarbon present in the treated exhaust stream below the threshold value.

[0033] The method may include controlling the abatement chamber to supply at least one of the at least one combustion by-product and the at least one hydrocarbon to the abated exhaust stream at a concentration greater than a threshold value and at a lower temperature than supplying at least one of the at least one combustion by-product and the at least one hydrocarbon to the abated exhaust stream at a concentration less than the threshold value.

[0034] The method may include controlling the abatement chamber to provide at least one of a plurality of combustion by-products and a plurality of hydrocarbons to the abated exhaust stream at initial concentrations of each, and configuring a catalyst bed to perform a plurality of catalytic reactions on the scrubbed exhaust stream to provide at least one of the plurality of combustion by-products and a plurality of hydrocarbons to the treated exhaust stream at concentrations lower than their initial concentrations.

[0035] The catalyst bed is used for the direct decomposition of NO, X and oxidation of at least one of CO and hydrocarbons.

[0036] The catalyst bed can include a catalyst material including at least one of a metal oxide material, a metal oxide, and a precious metal on a support.

[0037] The support may include at least one of titanium, aluminum, zirconium, and silicon-based oxides. Examples of such may include silica, silicalite, aluminosilicate titanium oxide, zirconia, alumina, and zeolites.

[0038] The precious metal can include at least one platinum group metal.

[0039] The platinum group metals can include at least one of platinum, palladium, rhodium, iridium, ruthenium, and osmium.

[0040] The abatement chamber can be configured to produce reaction by-products, such as CO, as described above, which can be treated using a catalyst for CO. Examples of such catalysts include, for example, hopcalite (copper manganese spinel), lanthanum copper oxide, or at least one of the precious metals on a support described above.

[0041] The catalytic materials for at least one of the direct decomposition of NO and oxidation of CO can include at least one of iron, cobalt, nickel, manganese, palladium, platinum, indium or silver impregnated on conventional supports such as alumina, silica, titania, or zeolite supports such as ZSM5, BEA, ferrierite, mordenite, and composite catalysts of copper, zinc, aluminum with alkali metals or alkaline earth metals can also be used.

[0042] The catalytic material for the direct reduction or decomposition of NOx can include at least one of Cu-ZSM5, a noble metal catalyst on a support material such as alumina or silica, or a metal-organic framework type catalyst.

[0043] The catalytic material for oxidizing at least one of CO and hydrocarbons comprises at least one of silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable zeolite support and / or other support comprising at least one of silicon, zirconium, aluminum and / or titanium based oxides; zeolite supports such as ZSM5, BEA, ferrierite and / or mordenite, where metals such as cobalt, nickel, manganese, palladium, indium and / or silver can be impregnated into such zeolite supports; and materials doped with molybdenum, niobium and / or tungsten based oxides and further doped with alkali, alkaline earth and / or barium.

[0044] It may be advantageous to operate the abatement chamber in the manner described above to increase the concentration of reaction by-products such as CO or hydrocarbons. These by-products may react on the catalyst bed to produce CO2 and / or react on the catalyst bed to produce NO2. xIt has been recognized that the drawback of such catalytic technology is related to its ability to operate in the presence of various concentrations of combustion by-products such as water vapor, CO2, O2, etc., originating from the scrubbed exhaust, as well as other compounds that may also be present in the original exhaust stream, such as CO, hydrocarbons, and / or NO. x Examples of suitable catalysts for include at least one of silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable zeolite support or on other supports including at least one of silicon, zirconium, aluminum or titanium based oxides. Alternatively, catalysts including zeolite supports such as ZSM5, BEA, ferrierite and / or mordenite can be used, and such zeolite supports can be impregnated with metals such as cobalt, nickel, iron, manganese, palladium, indium and / or silver. The catalyst material can also 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 can include multiple catalyst materials.

[0046] The method can include configuring the catalyst bed such that a catalytic material for reducing at least one of CO and hydrocarbons is positioned one of upstream and downstream of a catalytic material for directly decomposing NO.

[0047] Catalytic materials for the oxidation or decomposition of CO and / or hydrocarbons may typically be required to operate at a lower temperature than catalytic materials for the decomposition of NO. By positioning one downstream of the other, this helps ensure that the exothermic reaction caused by the upstream catalytic material heats up the downstream catalytic material. In some embodiments, the hydrocarbon / CO catalyst will be placed before the NO catalyst because the NO catalyst would otherwise overheat the NO. xIn addition, the hydrocarbon / CO catalyst may consume the CO or hydrocarbons required to promote the reduction or decomposition of NO. x In the presence of NO, N2O may be produced, which is removed by a downstream N2O catalyst. x Reduces the chance of contamination by NO x NO is removed on a preceding catalyst by reaction with hydrocarbons and / or CO. In another embodiment, it is preferred to position the NO catalyst upstream of the hydrocarbon catalyst so that the NO does not consume combustion by-products and / or hydrocarbons that would otherwise be consumed by the NO on the downstream catalyst bed. x This will result in further treatment of the

[0048] The method may include controlling the abatement chamber to cause an increase in an exothermic catalytic reaction that increases a concentration of at least one of the at least one combustion by-product and the at least one hydrocarbon and increases an operating temperature of the catalyst bed.

[0049] The method may include controlling the abatement chamber to increase the concentration of at least one of CO and hydrocarbons to cause an increase in exothermic catalytic reactions to increase the operating temperature of the catalyst bed.

[0050] The method may include controlling the abatement chamber to temporarily increase a concentration of at least one of the at least one combustion by-product and the at least one hydrocarbon to cause an increase in an exothermic catalytic reaction to increase an operating temperature of the catalyst bed.

[0051] The method can include controlling the abatement chamber to sequence an increase in the concentration of at least one of a plurality of combustion by-products and a plurality of hydrocarbons to cause an increase in the rate of a series of exothermic catalytic reactions.

[0052] The method may include controlling the abatement chamber to sequence an increase in concentration of one or more of CO, then hydrocarbons, then N2O to increase the rate of a series of exothermic catalytic reactions.

[0053] The method may include providing a heat exchanger for the catalyst bed and using the heat exchanger to preheat the effluent stream before it is fed to the abatement chamber.

[0054] Further particular and preferred aspects are set out in the accompanying 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 explicitly set out in the claims.

[0055] It should be understood that when features of an apparatus are described as operable to provide a certain function, this includes features of the apparatus that provide that function or that are adapted or configured to provide that function.

[0056] Embodiments of the present invention will now be further described with reference to the accompanying drawings. [Brief description of the drawings]

[0057] [Figure 1] 1 illustrates a schematic of an abatement apparatus according to one embodiment. [Figure 2A] 1 shows a schematic of a catalyst bed configuration. [Figure 2B] 1 shows a schematic of a catalyst bed configuration. [Figure 2C] 1 shows a schematic of a catalyst bed configuration. [Figure 2D] 1 shows a schematic of a catalyst bed configuration. [Figure 2E] 1 shows a schematic of a catalyst bed configuration. [Figure 2F] 1 shows a schematic of a catalyst bed configuration. [Figure 2G] 1 shows a schematic of a catalyst bed configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] Before describing the embodiments in more detail, an overview will first be provided. Some embodiments provide an arrangement for abating compounds in an exhaust stream, for example from a semiconductor processing tool. An abatement chamber receives an exhaust stream to be abated, performs abatement, and provides the abated exhaust stream to a scrubber arrangement, which scrubs the abated exhaust stream and provides a scrubbed exhaust stream. The scrubbed exhaust stream is provided to a catalyst bed. The scrubbed exhaust stream is catalytically reacted with a catalyst in the catalyst bed to provide a treated exhaust stream. This allows the abatement device to abate, remove, reduce the concentration, decompose or treat compounds present in the exhaust stream before the exhaust stream is typically vented to the atmosphere. The arrangement of the abatement chamber in combination with the catalyst bed allows compounds that would otherwise be problematic and energy intensive to abatement by the abatement chamber to instead be treated, decomposed or reacted into more suitable compounds using the catalyst bed. This allows the abatement chamber to be operated at a lower temperature, reducing stress on the abatement chamber as well as reducing the energy consumption of the abatement device and providing improved abatement of some compounds. In some embodiments, a combination of catalytic materials can be provided within the catalyst bed to aid in the treatment of different compounds or classes of compounds within the exhaust stream. Also, because the reactivity of some catalysts can be temperature dependent, a controller can be used to control the operation of the abatement chamber to cause some catalysts within the catalyst bed to undergo exothermic reactions in order to increase the heat adjacent the catalyst to achieve the required reactivity, thereby eliminating the need for electrical heaters to provide that heat. Additionally, in some embodiments, the catalyst bed acts as a heat exchanger to aid in preheating the incoming exhaust stream.

[0059] In some embodiments, different catalysts and different combinations of catalysts are provided to support different types of reactions to treat the compounds flowing over the catalyst bed. It is recognized that shortcomings of certain catalyst technologies relate to their ability to operate in the presence of various concentrations of combustion by-products such as water vapor, CO2, O2, etc., originating from the scrubbed effluent, as well as other compounds in the scrubbed effluent that may also be present in the original effluent stream.

[0060] In some embodiments, catalysts are provided that treat only CO. However, NO x The catalyst provided for treating both the +CO catalyst and the catalyst provided for treating the NO catalyst are x It should be understood that catalysts can be utilized for CO in the absence of NO or NO. Catalysts including one or more of hopcalite (copper manganese spinel) and / or lanthanum copper oxide for treating CO only can be used. Catalysts having any precious metal such as platinum, palladium, rhodium, iridium, ruthenium and / or osmium on a suitable zeolite support and / or other support having at least one of silicon, zirconium, aluminum or titanium can be used. Gold on a support such as ceria oxide can also be used for this purpose.

[0061] In some embodiments, catalysts for treating NO (i.e., removing NO without any additional reducing agent) are provided. Such catalysts include one or more of catalysts that exhibit NO reduction activity, such as Cu-ZSM5, catalysts such as noble metal catalysts on support materials such as alumina and / or silica, or metal-organic framework type catalysts.

[0062] In some embodiments, a catalyst is provided for treating NO+CO (i.e., removing NO using CO as a reductant). It should be understood that this may produce some NO and therefore requires a subsequent NO catalyst. In particular, the catalyst for treating NO+CO in the presence of water and oxygen includes one or more catalysts including any precious 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 including 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 may be further doped with alkali and / or alkaline earth materials.

[0063] In some embodiments, catalysts for treating NO are provided. Such catalysts include one or more of catalysts with zeolitic supports such as ZSM5, BEA, ferrierite, mordenite, and / or catalysts with conventional supports 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. Hopcalite (copper manganese spinel) can be utilized for this purpose, as can composite catalysts of copper, zinc, aluminum containing alkali metals and / or alkaline earth metals.

[0064] In some embodiments, a catalyst for treating NO+hydrocarbons is provided (or only a catalyst for treating only hydrocarbons is provided if it is utilized to adjust the reactor temperature). Such catalysts include one or more of catalysts having a zeolite support such as ZSM5, BEA, ferrierite 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. Noble metals such as palladium on suitable supports such as sulfated zirconia or titania can be utilized for this purpose.

[0065] Abatement device 1 shows a schematic of an abatement apparatus 10 according to one embodiment. The abatement apparatus 10 includes an abatement chamber 20 coupled to a downstream scrubber 30. In this embodiment, the scrubber 30 includes a weir and spray nozzle structure 40, a downstream sump 50, and a downstream composite packed tower and wet electrolytic precipitator 60. Downstream of the composite packed tower and wet electrolytic precipitator 60 is a catalyst bed 70.

[0066] Generally, the exhaust stream 80 (along with any necessary combustion reagents) enters the abatement chamber 20 where the compounds in the exhaust stream 80 are abated to produce an abated exhaust stream 85. The abated exhaust stream 85 flows into the downstream weir and spray nozzle structure 40 where it is cooled by the weir and where larger particulates are removed by the spray created by the spray nozzles, and then flows into the sump 50. The abated exhaust stream 85 then flows upwardly through the composite packed tower and wet electrolytic precipitator 60, which further traps particulates in the abated exhaust stream 85 and helps remove soluble compounds from within the abated exhaust stream 85. The abated exhaust stream 85 then continues downstream over the catalyst bed 70 where one or more catalytic reactions occur between compounds in the abated exhaust stream 85 to treat, decompose, or remove those compounds from the abated exhaust stream before discharging the treated exhaust stream 87, typically to the atmosphere.

[0067] As will be described in more detail below, the controller 90 can control the conditions within the abatement chamber 20 to vary the concentration of compounds exiting the abatement chamber in the abatement effluent stream 85 in order to cause one or more exothermic reactions to occur in the catalyst bed 70 in order to adjust the reactivity of one or more catalysts within the catalyst bed 70. In this manner, no heating elements need be provided at the catalyst bed 70 to control the reactivity of the catalyst bed 70.

[0068] 1, the catalyst bed 70 may be provided as part of a heat exchanger 75 to help preheat the exhaust stream 80 before it is introduced into the abatement chamber 20. This provides a degree of heat recovery that helps reduce the energy consumption of the abatement system 10.

[0069] The exhaust stream may contain a number of different compounds depending on the operation of the upstream semiconductor processing tool. For example, the exhaust stream may contain N2O, SiH4, NH3, and NF3 at different times and in different concentrations or amounts. Depending on the conditions within the abatement chamber, a variety of different compounds may exit the abatement chamber 20 in the abatement exhaust stream 85. For example, N2O may be present in the abatement exhaust stream as NO X , some residual N2O, as well as N2. Similarly, SiH4 may become SiO2 in the abatement effluent stream. NH3 may become NO X , CH4, CO2, and CO. NF3 is converted to NO in the abatement effluent stream. Xand HF. The presence of N2O, NO, NO2 and / or CO in the abatement exhaust stream is undesirable, and typically environmental and / or safety regulations require that the gas stream emitted from the abatement system 10 have concentrations or parts per million levels of these compounds below certain thresholds. However, optimizing the abatement chamber 20 to achieve these thresholds is difficult and typically requires very high energy expenditures. However, the catalyst bed 70 contains one or more catalysts optimized to aid in the catalytic reactions that treat, abate or break down these compounds into safe compounds such as carbon dioxide, nitrogen and oxygen.

[0070] 2A-2G show schematic diagrams of various catalyst bed 70A-70G configurations according to embodiments. The catalyst beds 70A-70G are provided in suitable physical configurations to ensure that sufficient surface area is provided to support the required reactions. The configurations may also be provided as part of a heat exchanger 75.

[0071] 2A shows an arrangement where excess CO and O2 in the abatement effluent stream 85 are remediated. In this example, catalyst bed 70A includes Catalyst A. Catalyst A allows CO2 to be produced from CO and O2.

[0072] 2B shows an arrangement where excess CO, O2, NO and NO2 in the abatement exhaust stream 85 are treated. In this example, catalyst bed 70B contains catalyst A and catalyst B. Catalyst A operates as described above, while catalyst B allows N2 and O2 to be produced from NO and NO2.

[0073] 2C shows an arrangement where excess CO and / or hydrocarbons, O2, NO and NO2 in the abatement exhaust stream 85 are treated. In this example, catalyst bed 70C contains a single catalyst C. Catalyst C allows CO2 to be produced from CO and / or hydrocarbons and O2, as well as N2 and O2 from NO and NO2. This catalyst can also be used to treat only hydrocarbons or only CO, which are used to provide heat to raise the catalyst temperature.

[0074] 2D shows an arrangement where excess N2O in the abatement effluent stream 85 is treated. In this example, catalyst bed 70D includes catalyst D. Catalyst D allows N2 and O2 to be produced from N2O.

[0075] 2E shows an arrangement where excess N2O, NO, and NO2 are treated in the abatement exhaust stream 85. In this example, catalyst bed 70E contains catalyst B and catalyst D, each of which operates as described above.

[0076] 2F shows an arrangement where excess CO, O2, N2O, NO, and NO2 are treated in the abatement exhaust stream 85. In this example, catalyst bed 70F includes catalyst A, catalyst B, and catalyst D, each of which operates as described above.

[0077] FIG. 2G shows an arrangement where excess CO, O2, N2O, NO and NO2 in the abatement exhaust stream 85 are treated. In this example, catalyst bed 70G includes catalyst C and catalyst D, each operating as described above. In this arrangement, catalyst C can be placed before catalyst D, because otherwise catalyst D may consume CO or may 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, so that N2O does not cause a competing reaction with the hydrocarbon / CO reaction occurring on catalyst C. In this case, catalyst D also provides heat to support the reaction on catalyst C.

[0078] Some examples of catalysts A for the oxidation of CO include one or more of hopcalite (copper manganese spinel) or lanthanum copper oxide, which can be used for CO oxidation in the presence of oxygen. Catalysts containing any 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. Also, catalysts such as gold on cerium oxide can be used for this purpose.

[0079] NO X Some examples of catalyst B for the decomposition or reduction of NO include one or more of catalysts such as Cu-ZSM5, and / or noble metal catalysts on support materials such as alumina and / or silica, and / or metal-organic framework type catalysts, which exhibit NO reduction activity.

[0080] Some examples of catalysts C for reacting NO with CO and / or hydrocarbons include one or more of silver, platinum, palladium, rhodium, iridium, ruthenium and / or osmium on suitable zeolite supports and / or other supports including at least one of silicon, zirconium, aluminum and titanium based oxides. Alternatively, catalysts including zeolite supports such as ZSM5, BEA, ferrierite 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. The catalytic material can also be doped with oxides based on molybdenum, niobium and / or tungsten and / or further doped with alkali, alkaline earth and / or barium.

[0081] Some examples of catalyst D for the direct decomposition of NO can include one or more of hopcalite (copper manganese spinel); lanthanum copper oxide; iron, cobalt, nickel, manganese, palladium, platinum, indium and / or silver impregnated on conventional supports such as alumina, silica and / or titania or on zeolitic supports such as ZSM5, BEA, ferrierite and / or mordenite; copper, zinc, aluminum composite catalysts also containing alkali and / or alkaline earth metals. In some embodiments, the NO+CO catalyst is placed before the NO catalyst because otherwise the NO catalyst may consume CO or be poisoned by NO.

[0082] It can thus be seen that some embodiments provide an apparatus, including a burner-scrubber and a catalyst, for abatement of N2O, NO, NO2 and CO, and a method of operating the apparatus. As mentioned above, some semiconductor processes use N2O, which is a potent greenhouse gas. Combustion abatement of N2O can result in partial conversion to NO and to some extent NO2, both of which are harmful to human health and the environment. Combustion destruction of other nitrogen-containing gases, such as NH3 or NF3, can also result in NO x This can lead to the production of NO x The formation of CO can be limited by adjusting the combustor conditions (fuel to oxidizer ratio), but this generally leads to greater CO formation.

[0083] Some embodiments provide a burner-scrubber with a downstream catalyst bed for abatement of either N2O, NO, NO2, and / or CO. Ideally, burner conditions are optimized for abatement of harmful substances other than N2O, and ideally N2O should pass through the burner unabated. A downstream wet scrubber may seem counterintuitive, but it helps remove acid gases and particulate matter to protect the catalyst. The wet scrubber may further comprise a wet electrolytic precipitator. The catalyst may be one or more of a variety of materials with demonstrable N2O, NO, NO2, and / or CO destruction performance. Hopcalite, a mixture of manganese oxide and copper oxide, is a surprising but useful choice. Various grades with different detailed compositions are available and are optimized for one or more specific applications. The advantage of using hopcalite is that it oxidizes CO at room temperature and hydrocarbons at moderately high temperatures. Temperatures in excess of 400°C are required for abatement of N2O. Therefore, the burner can be intentionally operated under rich conditions (leading to the production of CO) to heat the catalyst. If the abatement is adjusted to also release CO, then NO X This leads to lower emissions, and the Hopcalite catalyst then serves to reduce CO in the final exhaust, which in turn serves to remove the high NO concentration resulting from the modified burner conditions. Further synergistic effects are also evident if heating can be achieved by passing 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 stream. Since the destruction of NO on the catalyst is exothermic, the heat generated can offset losses from the system. If the temperature is below a predefined 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 over the catalyst. The catalytic reactor can also be equipped with an electric heater. For certain combinations of gases in the exhaust stream, the exhaust stream from the abatement chamber will have NO levels higher than the environmental threshold. X In this case, NO is produced with the aid of a hydrocarbon catalyst. XIn addition, burner conditions can change the oxygen level in the exhaust, which can lead to NO X It is understood that hydrocarbons and / or CO may be consumed preferentially over reaction with NO. For example, other catalysts, such as iridium supported on a support such as silica, and optionally doped with metals such as tungsten and barium, are advantageous in that CO is flowed over the catalyst in the absence of oxygen and / or water to act as a reducing agent during NO and NO2 abatement. In other embodiments, it may be preferred to utilize ferrierites, such as cobalt ferrierites, optionally doped with, for example, platinum group metals and / or indium, which oxidize methane to NO. x removal and reactor heating, and can also enable simultaneous N2O removal. The catalyst bed can contain up to three separate catalysts, one optimized for direct decomposition of N2O, another optimized for reduction of NO and NO2, and a third optimized for oxidation of CO and hydrocarbons. A particular set of catalysts is selected because they may be arranged in a specified synergistic manner. For example, historically, problems associated with platinum group metal catalysts such as the iridium or platinum catalysts mentioned above have been a result of by-product N2O production, but by utilizing these platinum group metal catalysts that are poor at methane conversion and placing an iridium catalyst before a cobalt ferrierite catalyst, both N2O and NO removal can be successfully achieved.

[0084] Although exemplary embodiments of the present invention have been disclosed in detail herein with reference to the accompanying drawings, it is understood that the present invention is not limited to the precise embodiments, and various changes and modifications can be made by those skilled in the art without departing from the scope of the present invention as defined by the appended claims and their equivalents. [Explanation of symbols]

[0085] 10 Abatement equipment 20 Abatement room 30 Scrubber 40 Weir and spray nozzle structure 50 Samp 60 Composite packed tower and wet electrolytic dust collector 70, 70A-G catalyst bed 75 Heat exchanger 80 Discharge stream 85 Abatement of waste streams 87 Treated waste stream 90 Control device

Claims

1. 1. An abatement apparatus for abating an exhaust stream from a semiconductor processing tool, comprising: an abatement chamber configured to receive the exhaust stream and provide an abated exhaust stream; a wet scrubber positioned downstream of the abatement chamber and configured to receive the abatement effluent stream and to provide a scrubbed effluent stream; a catalyst bed positioned downstream of the wet scrubber and configured to receive the scrubbed effluent stream and to provide a treated effluent stream; The harm-eliminating device comprises:

2. The abatement room is providing the abatement exhaust stream containing at least one of at least one combustion by-product and at least one hydrocarbon, the catalyst bed being configured to reduce a concentration of the at least one of the at least one combustion by-product and at least one hydrocarbon present in the treated exhaust stream; providing at least one of the at least one combustion by-product and at least one hydrocarbon in a concentration greater than a threshold value to the abatement exhaust stream, the catalyst bed being configured to reduce a concentration of the at least one of the at least one combustion by-product and at least one hydrocarbon present in the treated exhaust stream below the threshold value; providing at least one of a plurality of combustion by-products and a plurality of hydrocarbons to the abatement exhaust stream at an initial concentration of each, and the catalyst bed is configured to perform a plurality of catalytic reactions on the scrubbed exhaust stream to provide at least one of the plurality of combustion by-products and a plurality of hydrocarbons to the treated exhaust stream at a concentration less than the initial concentration of each. The abatement device of claim 1 , configured to perform at least one of the following:

3. 3. The abatement device of claim 1, wherein the catalyst bed comprises a catalyst material comprising at least one of a metal oxide material, a metal oxide, and a precious metal on a support, and preferably the support comprises at least one of titania, alumina, zirconium, and silicon-based oxide.

4. The catalyst bed comprises: N 2 Direct decomposition of O NO X and at least one of direct reduction and decomposition of Oxidation of at least one of CO and hydrocarbons; 4. The abatement device of claim 1, further comprising at least one catalytic material for at least one of:

5. N 2 The catalytic material for the direct decomposition of O and oxidation of CO comprises: Hopcalite (copper manganese spinel) Lanthanum copper oxide; iron, cobalt, nickel, manganese, palladium, platinum, indium, and / or silver impregnated on a conventional support such as alumina, silica, and / or titania, and / or a zeolitic support such as ZSM5, BEA, ferrierite, and / or mordenite; a copper, zinc and / or aluminum composite catalyst containing an alkali metal and / or an alkaline earth metal; The abatement apparatus of claim 4 , comprising at least one of:

6. NO X The catalytic material for the reduction or decomposition of Cu-ZSM5, a noble metal catalyst and / or a metal-organic framework type catalyst on a support material such as alumina and / or silica; The abatement device according to claim 4 or 5, comprising at least one of the following:

7. The catalytic material for oxidizing at least one of CO and hydrocarbons comprises: silver, platinum, palladium, rhodium, iridium and / or ruthenium on a suitable zeolite support and / or on other supports comprising at least one of silicon, zirconium, aluminum and / or titanium based oxides; a zeolitic support such as ZSM5, BEA, ferrierite and / or mordenite, which can be impregnated with a metal such as cobalt, nickel, manganese, palladium, indium or silver; a material doped with molybdenum, niobium, and / or tungsten based oxides and further doped with alkali, alkaline earth and / or barium; The abatement device according to claim 4 , comprising at least one of the following:

8. 8. The abatement apparatus of claim 1, wherein the catalyst bed comprises a plurality of catalytic materials.

9. The catalytic material for oxidizing at least one of CO and hydrocarbons is N 2 9. The abatement device of claim 4, wherein the abatement device is disposed one of upstream and downstream of the catalytic material for the direct decomposition of O.

10. The abatement room is increasing the concentration of at least one of at least one combustion by-product and at least one hydrocarbon to cause an increase in exothermic catalytic reactions to increase 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 increase the operating temperature of the catalyst bed; 10. The abatement apparatus of claim 1 , configured to perform at least one of the following:

11. 11. The abatement apparatus of 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 the at least one hydrocarbon to cause the increase in the exothermic catalytic reaction and increase the operating temperature of the catalyst bed.

12. 12. The abatement apparatus of claim 1, wherein the abatement chamber is configured to sequence increasing concentrations of at least one of a plurality of combustion by-products and a plurality of hydrocarbons to increase the rate of a series of exothermic catalytic reactions.

13. The abatement chamber is configured to detect CO, then hydrocarbons, then N 2 13. The abatement apparatus of claim 12 configured to sequence an increase in concentration of one or more of O to cause said increase in rate of said series of exothermic catalytic reactions.

14. 14. The abatement apparatus of any of claims 1 to 13, wherein the catalyst bed comprises a heat exchanger configured to preheat the exhaust stream before it is provided to the abatement chamber.

15. 1. A method for abating an exhaust stream from a semiconductor processing tool, comprising: receiving the exhaust stream, abating the exhaust stream in an abatement chamber, and providing an abated exhaust stream; receiving the abatement effluent stream, scrubbing the abatement effluent stream with a wet scrubber, and providing the scrubbed effluent stream as a scrubbed effluent stream; receiving the scrubbed exhaust stream and treating the scrubbed exhaust stream with a catalyst bed positioned downstream of the wet scrubber to provide a treated exhaust stream; The method includes:

Images