Device

Abstract

An apparatus and method are disclosed. The apparatus includes an abatement chamber of an abatement device that processes an exhaust stream from a semiconductor processing tool to provide a combustion exhaust stream having exhaust particles, and a first atomizer located downstream of the abatement chamber, the first atomizer configured to generate droplets having a droplet size based on the particle size of the exhaust particles to be removed from the combustion exhaust stream. In this manner, the atomizer can generate droplets that aid in the removal of the exhaust particles from the combustion exhaust stream, combine with the exhaust particles, or adhere to the exhaust particles.

Description

[Technical Field]

[0001] APPARATUS AND METHODS FIELD OF THE INVENTION Embodiments relate to an apparatus for treating an exhaust stream containing solid particles, such as SiO2, and acid gases, such as HCl. [Background technology]

[0002] Abatement systems are known. Such systems are used, for example, to treat exhaust gases resulting from epitaxial growth or other semiconductor manufacturing processes. Epitaxial growth processes are increasingly being used for high-speed semiconductor devices, both for silicon and compound semiconductor applications. The epitaxial layer is a carefully grown single-crystalline silicon film. Epitaxial growth is performed under vacuum in a hydrogen atmosphere at high temperatures of approximately 800–1100 °C, using silane or one of the chlorosilane compounds, such as trichlorosilane or dichlorosilane, as the silicon source gas. Epitaxial growth processes often involve doping with small amounts of boron, phosphorus, arsenic, germanium, or carbon, as needed for the device being fabricated. Etching gases supplied to the process chamber may include halogen compounds such as HCl, HBr, BCl3, Cl2, and Br2, and combinations thereof. Hydrogen chloride (HCl) or other halogen compounds, such as SF6 or NF3, may be used to clean the chamber during processing.

[0003] In such processes, only a small portion of the gas supplied to the process chamber is consumed within the process chamber, and therefore a high percentage of the gas supplied to the process chamber is exhausted from the process chamber along with solid and gaseous by-products from the process occurring within the chamber. A process tool typically has multiple process chambers, each of which may be at a different stage in a deposition, etching, or cleaning process. Thus, the exhaust stream formed from the combination of gases exhausted from the chambers during processing may have a variety of different compositions.

[0004] Before the exhaust stream is released into the atmosphere, it is treated using an abatement device to remove certain gases or solid particles. Acid gases, such as HF and HCl, are typically removed from the gas stream using a packed tower scrubber, where the acid gases are dissolved in a scrubbing liquid flowing through the scrubber. Because silanes are pyrophoric, the exhaust stream is typically sent to a thermal incinerator or abatement chamber before being sent to the scrubber to react the silanes or other pyrophoric gases contained in the exhaust stream with air. Some perfluorinated compounds, such as NF3, can also be converted to HF in the abatement chamber.

[0005] When silane is burned, large amounts of silica (SiO2) particles are produced. Other compounds also produce particles when exposed to heat. While many of these particles are captured in suspension by the dam and quench nozzle, it has been observed that relatively small particles (e.g., less than 1 micron in size) are captured relatively poorly by the scrubbing liquor. Summary of the Invention [Problem to be solved by the invention]

[0006] While such systems allow for the treatment of exhaust gas streams, they suffer from a number of drawbacks. It would therefore be desirable to provide an improved abatement system. [Means for solving the problem]

[0007] According to a first aspect, an apparatus is provided, comprising: an abatement chamber of an abatement device that processes an exhaust stream from a semiconductor processing tool to provide a combustion exhaust stream having exhaust particles; and a first atomizer located downstream of the abatement chamber, the first atomizer configured to generate droplets having a droplet size based on a particle size of the exhaust particles removed from the combustion exhaust stream.

[0008] A first aspect recognizes that a problem with existing designs is that the amount of exhaust particles that can be removed from the exhaust stream is limited. This is believed to be because the particles remain suspended in the combustion exhaust stream, making them difficult to remove. Accordingly, an apparatus is provided. The apparatus can include an abatement chamber. The abatement chamber can be provided as part of an abatement apparatus. The abatement apparatus can be configured to treat, process, or abate an exhaust stream provided by a semiconductor processing tool. The abatement chamber can provide or generate the combustion exhaust stream. The combustion exhaust stream can have exhaust particles suspended therein. The apparatus can include an atomizer that can receive the combustion exhaust stream from the abatement chamber. The atomizer can be configured or arranged to generate liquid droplets. The droplets can have a droplet size based on, related to, dependent on, or proportional to the particle size of the exhaust particles removed from the combustion exhaust stream. In this manner, the atomizer can generate liquid droplets that bond with or adhere to the exhaust particles, aiding in their removal from the combustion exhaust stream.

[0009] The apparatus can include a second atomizer located downstream of the first atomizer to generate additional droplets that can combine with the exhaust particles and / or previously combined exhaust particles and droplets generated by the first atomizer to aid in their removal from the combustion exhaust stream.

[0010] The apparatus may include a quench spray section upstream of the first atomizer and a spray nozzle for scrubbing the water-soluble gas upstream of the second atomizer. Typically, the quench spray section may be disposed in a quenching stage downstream of the abatement chamber. Typically, the spray nozzle may be disposed in a packed tower downstream of the first atomizer and upstream of the second atomizer.

[0011] The first atomizer can be located downstream of the quenching stage.

[0012] The second atomizer can be positioned toward the inlet of the packed tower.

[0013] The second atomizer can be positioned toward the exhaust outlet of the packed tower. By positioning the first atomizer toward one end of the packed tower and the second atomizer toward the other end of the packed tower, exhaust particles and droplets have space to adhere or combine and agglomerate, which helps remove them from the combustion exhaust stream.

[0014] A second atomizer can be placed upstream of the cyclone or mist filter. This, in turn, helps produce larger particles that can be more effectively removed. The cyclone or mist filter primarily removes water from the discharge stream. The cyclone / mist filter can remove fine particles in conjunction with the upper atomizer.

[0015] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size distribution based on the particle size distribution of exhaust particles removed from the combustion exhaust stream. Accordingly, the droplet size distribution can also be configured to match the particle size distribution to help ensure an appropriate number of different sized droplets are available based, related, dependent, or proportional to the different sizes of the particles.

[0016] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size distribution that overlaps with the particle size distribution of the combustion particles being removed from the combustion exhaust stream. Thus, the size distributions need not match perfectly, but may simply overlap or share a common size to promote bonding or adhesion between the droplets and the combustion particles. Similarly, the droplet size may be a multiple of the particle size (e.g., the droplet size may be up to 200 times the particle size), but the size distribution profiles of the droplets compared to the particles may overlap or share a common portion.

[0017] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size distribution that matches the particle size distribution of combustion particles removed from the combustion exhaust stream. Although the droplet size can be a multiple of the particle size (e.g., the droplet size can be up to 200 times the particle size), the size distribution profile of the droplets compared to the particles can match or have a similar profile.

[0018] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size that is up to 200 times, preferably up to 20 times, the particle size of the exhaust particles to be removed from the combustion exhaust stream. Thus, the relative sizes need not match exactly. The relative sizes can differ by a factor of 200. It has been found that a relative size difference of up to 200 times still promotes adequate attachment or bonding of the combustion particles and droplets to cause removal from the combustion exhaust stream.

[0019] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size between 20 and 50 times the particle size of the exhaust particles being removed from the combustion exhaust stream.

[0020] The first atomizer and / or the second atomizer can be configured to produce droplets within a droplet size distribution having sizes that match particles within the particle size distribution of combustion particles removed from the combustion exhaust stream.

[0021] The first atomizer and / or the second atomizer can include multiple nozzles configured to generate droplets, which can increase the number and spatial distribution of droplets.

[0022] The nozzles can be supplied with an atomizing liquid and gas to generate droplets, and by adjusting the atomizing liquid and gas, the size and size distribution of the droplets can be adjusted.

[0023] The multiple nozzles are arranged in parallel with the source of atomizing liquid and the source of atomizing gas, and each nozzle can produce droplets having a consistent droplet size distribution.

[0024] The multiple nozzles can be configured to produce droplets having different droplet size distributions from each nozzle, such that each nozzle can produce a different droplet size distribution that together produce the required droplet size distribution to match the combustion exhaust flow.

[0025] The multiple nozzles can be arranged in groups, with each group arranged in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets having a consistent droplet size distribution from each group of nozzles.

[0026] The nozzles in each group are arranged in series with a source of atomizing liquid and a source of atomizing gas, and each nozzle in the group can produce droplets having a different droplet size distribution.

[0027] Multiple nozzles can be arranged in series with a source of atomizing liquid and a source of atomizing gas to produce droplets with different droplet size distributions from each nozzle. Pressure drop between the nozzles can help produce different size distributions at different nozzles.

[0028] A source of atomizing liquid is fed into one end of the series and a source of atomizing gas is fed into the other end of the series, capable of producing droplets having different droplet size distributions from each nozzle.

[0029] The nozzles can be positioned to generate droplets of different sizes at different locations in the discharge stream. The different sizes can accommodate different sizes of particles found in different locations. For example, smaller particles can be present in faster flow regions of the device, such as toward the center of the packed tower inlet, while larger particles can be present in slower flow regions, such as toward the ends of the packed tower inlet. Thus, in this example, the nozzles configured to generate smaller droplets can be positioned toward the center of the packed tower inlet, and the nozzles configured to generate larger droplets can be positioned toward the ends of the packed tower inlet.

[0030] The nozzles can be oriented to produce droplets that travel upstream, downstream and / or across the atomizer.

[0031] The nozzle can be oriented to produce droplets that travel both upstream and downstream of the atomizer.

[0032] The nozzles may be oriented to produce droplets in a direction opposite to the direction of the combustion exhaust flow.

[0033] The first atomizer and / or the second atomizer may be supplied with atomizing gas at up to 300 liters per minute, preferably up to 250 liters per minute (measured with the flow device set at 0° C.).

[0034] The first atomizer and / or the second atomizer may be supplied with atomizing gas at a pressure of up to 10 bar, preferably up to 6 bar.

[0035] The first atomizer and / or the second atomizer may be supplied with up to 30 liters per hour, preferably up to 22 liters per hour of spray liquid.

[0036] The first atomizer and / or the second atomizer may be supplied with spray liquid at a pressure of up to 2 bar, preferably up to 1.5 bar.

[0037] The atomizing gas may consist of nitrogen and / or compressed dry air, and the atomizing liquid may consist of water.

[0038] The first atomizer can include at least one nozzle, and the second atomizer can include at least one nozzle.

[0039] The first atomizer may comprise at least six nozzles arranged in three parallel groups with two nozzles for the source of atomizing liquid and two for the source of atomizing gas.

[0040] The first atomizer may include at least seven nozzles with a source of atomizing liquid and a source of atomizing gas arranged in parallel.

[0041] According to a second aspect, an apparatus is provided, comprising: an abatement chamber of an abatement device configured to process an exhaust stream from a semiconductor processing tool to provide a combustion exhaust stream having combustion particles; a first atomizer located downstream of the abatement chamber and configured to generate droplets that entrap at least a portion of the combustion particles; and a second atomizer located downstream of the first atomizer and configured to generate droplets that entrap at least a portion of the combustion particles.

[0042] The second aspect recognizes that a problem with existing arrangements is that they limit the amount of exhaust particles that can be removed from the exhaust stream, believed to be because the particles remain suspended in the combustion exhaust stream and are therefore difficult to remove.

[0043] Accordingly, an apparatus is provided. The apparatus can include an abatement chamber. The abatement chamber can be provided as part of an abatement apparatus. The abatement apparatus is configured to treat, process, or abate an exhaust stream provided by a semiconductor processing tool. The abatement chamber can provide or generate a combustion exhaust gas stream. The combustion exhaust stream can have exhaust particles suspended therein. The apparatus can include a first atomizer capable of receiving the combustion exhaust stream from the abatement chamber. The first atomizer can be configured or arranged to generate liquid droplets. The liquid droplets can entrap, capture, adhere, or combine with at least a portion of the combustion particles. The apparatus can include a second atomizer. The second atomizer can be located downstream of the first atomizer or located remotely from the first atomizer. The second atomizer can receive the combustion exhaust stream from the first atomizer. The second atomizer can be configured or arranged to generate liquid droplets. The liquid droplets can entrap, capture, adhere, or combine with at least a portion of the combustion particles. In this manner, the atomizer can generate droplets that combine with or adhere to the exhaust particles, aiding in their removal from the combustion exhaust stream. By providing a second atomizer, additional droplets can be generated that can combine with the exhaust particles generated from the first atomizer and / or with already combined exhaust particles and droplets, thereby aiding in their removal from the combustion exhaust stream.

[0044] The apparatus may include a quench spray section upstream of the first atomizer and a spray nozzle for scrubbing the water-soluble gas upstream of the second atomizer. Typically, the quench spray section may be disposed in a quenching stage downstream of the abatement chamber. Typically, the spray nozzle may be disposed in a packed tower downstream of the first atomizer and upstream of the second atomizer.

[0045] The first atomizer can be located downstream of the quenching stage.

[0046] The first atomizer can be positioned toward the inlet of the packed tower.

[0047] The second atomizer can be positioned toward the outlet of the packed tower.

[0048] The second atomizer may be located upstream of one of the cyclone stage and the mist filter.

[0049] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size distribution based on the particle size distribution of exhaust particles removed from the combustion exhaust stream.

[0050] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size distribution that overlaps with the particle size distribution of the combustion particles removed from the combustion exhaust stream. Similarly, the droplet size can be a multiple of the particle size (e.g., the droplet size can be up to 200 times the particle size), but the size distribution profiles of the droplets compared to the particles can overlap or share a common portion.

[0051] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size distribution that matches the particle size distribution of combustion particles removed from the combustion exhaust stream. Although the droplet size can be a multiple of the particle size (e.g., the droplet size can be up to 200 times the particle size), the size distribution profile of the droplets compared to the particles can match or have a similar profile.

[0052] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size that is up to 200 times, preferably up to 20 times, the particle size of the exhaust particles being removed from the combustion exhaust stream.

[0053] The first atomizer and / or the second atomizer can be configured to produce droplets having a droplet size between 20 and 50 times the particle size of the exhaust particles being removed from the combustion exhaust stream.

[0054] The first atomizer and / or the second atomizer can be configured to produce droplets within a droplet size distribution having sizes that match particles within the particle size distribution of combustion particles removed from the combustion exhaust stream.

[0055] The first atomizer and / or the second atomizer can include a plurality of nozzles configured to produce droplets.

[0056] The multiple nozzles can be supplied with an atomizing liquid and an atomizing gas for producing droplets.

[0057] The multiple nozzles are arranged in parallel with the source of atomizing liquid and the source of atomizing gas, and each nozzle can produce droplets having a consistent droplet size distribution.

[0058] The multiple nozzles can be configured to produce droplets from each nozzle having a different droplet size distribution.

[0059] The multiple nozzles can be arranged in groups of nozzles, each group arranged in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets having a consistent droplet size distribution from each group of nozzles.

[0060] The nozzles in each group are arranged in series with a source of atomizing liquid and a source of atomizing gas, and each nozzle in that group can produce droplets having a different droplet size distribution.

[0061] Multiple nozzles can be arranged in series with a source of atomizing liquid and a source of atomizing gas to produce droplets having different droplet size distributions from each nozzle.

[0062] A source of atomizing liquid is fed into one end of the series and a source of atomizing gas is fed into the other end of the series, capable of producing droplets having different droplet size distributions from each nozzle.

[0063] The multiple nozzles can be arranged to produce droplets of different sizes at different locations in the discharge stream.

[0064] The nozzles can be oriented to produce droplets that travel upstream, downstream and / or across the atomizer.

[0065] The nozzle can be oriented to produce droplets that travel both upstream and downstream of the atomizer.

[0066] The nozzles may be oriented to produce droplets in a direction opposite to the direction of the combustion exhaust flow.

[0067] The first atomizer and / or the second atomizer may be supplied with atomizing gas at up to 300 liters per minute, preferably up to 250 liters per minute (measured with the flow device set at 0° C.).

[0068] The first atomizer and / or the second atomizer may be supplied with atomizing gas at a pressure of up to 10 bar, preferably up to 6 bar.

[0069] The first atomizer and / or the second atomizer may be supplied with up to 30 liters per hour, preferably up to 22 liters per hour of spray liquid.

[0070] The first atomizer and / or the second atomizer may be supplied with spray liquid at a pressure of up to 2 bar, preferably up to 1.5 bar.

[0071] The atomizing gas may consist of nitrogen and / or compressed dry air, and the atomizing liquid may consist of water.

[0072] The first atomizer can include at least one nozzle, and the second atomizer can include at least one nozzle.

[0073] The first atomizer may comprise at least six nozzles arranged in three parallel groups with two nozzles for the source of atomizing liquid and two for the source of atomizing gas.

[0074] The first atomizer may include at least seven nozzles with a source of atomizing liquid and a source of atomizing gas arranged in parallel.

[0075] According to a third aspect, a method is provided, the method including receiving a flue gas stream having combustion particles from an abatement chamber of an abatement apparatus that treats an exhaust stream from a semiconductor processing tool, and removing the combustion particles from the flue gas stream using a first atomizer located downstream of the abatement chamber configured to generate droplets having a droplet size based on a particle size of the combustion particles removed from the flue gas stream.

[0076] The method can include disposing a second atomizer downstream from the first atomizer.

[0077] The method can include disposing a quench spray section upstream of the first atomizer and disposing a spray nozzle for scrubbing the water-soluble gas upstream of the second atomizer. Typically, the method can include disposing the quench spray section in a quenching stage downstream of the abatement chamber. Typically, the method can include disposing spray nozzles in a packed tower downstream of the first atomizer and upstream of the second atomizer.

[0078] The method can include disposing a first atomizer downstream of the quenching stage.

[0079] The method can include positioning a first atomizer toward an inlet of the packed tower.

[0080] The method can include positioning a second atomizer toward the outlet of the packed tower.

[0081] The method may include disposing a second atomizer upstream of one of the cyclone stage and the mist filter.

[0082] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution based on a particle size distribution of exhaust particles removed from the combustion exhaust stream.

[0083] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution that overlaps with a particle size distribution of combustion particles removed from the combustion exhaust stream.

[0084] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution that matches the particle size distribution of combustion particles removed from the combustion exhaust stream.

[0085] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size that is up to 200 times, preferably up to 20 times, the particle size of the exhaust particles removed from the combustion exhaust stream.

[0086] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size that is between 20 and 50 times the particle size of the exhaust particles removed from the combustion exhaust stream.

[0087] The method can include configuring the first atomizer and / or the second atomizer to produce droplets within a droplet size distribution having sizes that match particles within a particle size distribution of combustion particles removed from the combustion exhaust stream.

[0088] The first atomizer and / or the second atomizer can include a plurality of nozzles configured to produce droplets.

[0089] The method can include supplying an atomizing liquid and an atomizing gas to a plurality of nozzles to generate droplets.

[0090] The method can include arranging a plurality of nozzles in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets from each nozzle with a consistent droplet size distribution.

[0091] The method can include configuring a plurality of nozzles to produce droplets with different droplet size distributions from each nozzle.

[0092] The method can include arranging a plurality of nozzles into nozzle groups, each nozzle group in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets having a consistent droplet size distribution from each nozzle group.

[0093] The method can include arranging each group of nozzles in series with a source of atomizing liquid and a source of atomizing gas to produce droplets having a different droplet size distribution from each nozzle in the group.

[0094] The method can include disposing a plurality of nozzles in series with a source of atomizing liquid and a source of atomizing gas to produce droplets from each nozzle having a different droplet size distribution.

[0095] The method can include providing a source of atomizing liquid at one end of the series and a source of atomizing gas at the other end of the series to produce droplets having different droplet size distributions from each nozzle.

[0096] The method may include arranging multiple nozzles to generate droplets of different sizes at different locations in the discharge stream.

[0097] The method can include orienting the nozzle to produce droplets that travel upstream, downstream, and / or across the atomizer.

[0098] The method can include orienting the nozzle to produce droplets that travel both upstream and downstream of the atomizer.

[0099] The method may include orienting the nozzle to produce droplets traveling in a direction opposite to the direction of the combustion exhaust flow.

[0100] The method may include supplying the first atomizer and / or the second atomizer with nebulizing gas at up to 300 liters per minute, preferably up to 250 liters per minute (measured from a flow device set at 0°C).

[0101] The method may include supplying the first atomizer and / or the second atomizer with an atomizing gas at a pressure of up to 10 bar, preferably up to 6 bar.

[0102] The method may include supplying the first atomizer and / or the second atomizer with up to 30 litres per hour, preferably up to 22 litres per hour of spray liquid.

[0103] The method may comprise supplying the first atomizer and / or the second atomizer with spray liquid at a pressure of up to 2 bar, preferably up to 1.5 bar.

[0104] The atomizing gas may consist of nitrogen and / or compressed dry air, and the atomizing liquid may consist of water.

[0105] The first atomizer can include at least one nozzle, and the second atomizer can include at least one nozzle.

[0106] The first atomizer may comprise at least six nozzles arranged in three parallel groups with two nozzles for the source of atomizing liquid and two for the source of atomizing gas.

[0107] The first atomizer may include at least seven nozzles arranged in parallel with a source of atomizing liquid and a source of atomizing gas.

[0108] The method can include conveying the combustion exhaust stream with the droplets from the first atomizer towards a second atomizer to coalesce at least some of the droplets and at least some of the exhaust particles.

[0109] According to a fourth aspect, a method is provided, the method including receiving a combustion exhaust stream having combustion particles from an abatement chamber of an abatement apparatus that processes an exhaust stream from a semiconductor processing tool, and removing the combustion particles from the combustion exhaust stream using a first atomizer located downstream of the abatement chamber and configured to generate droplets that entrap at least a portion of the combustion particles, and a second atomizer located downstream of the first atomizer and configured to generate droplets that entrap at least a portion of the combustion particles.

[0110] The method can include disposing a quench spray section upstream of the first atomizer and disposing a spray nozzle for scrubbing the water-soluble gas upstream of the second atomizer. Typically, the method can include disposing the quench spray section in a quenching stage downstream of the abatement chamber. Typically, the method can include disposing spray nozzles in a packed tower downstream of the first atomizer and upstream of the second atomizer.

[0111] The method can include disposing a first atomizer downstream of the quenching stage.

[0112] The method can include positioning a first atomizer toward an inlet of the packed tower.

[0113] The method can include positioning a second atomizer toward the outlet of the packed tower.

[0114] The method may include disposing a second atomizer upstream of one of the cyclone stage and the mist filter.

[0115] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution based on a particle size distribution of exhaust particles removed from the combustion exhaust stream.

[0116] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution that overlaps with a particle size distribution of combustion particles removed from the combustion exhaust stream.

[0117] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution that matches the particle size distribution of combustion particles removed from the combustion exhaust stream.

[0118] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size that is up to 200 times, preferably up to 20 times, the particle size of the exhaust particles removed from the combustion exhaust stream.

[0119] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size that is between 20 and 50 times the particle size of the exhaust particles removed from the combustion exhaust stream.

[0120] The method can include configuring the first atomizer and / or the second atomizer to produce droplets within a droplet size distribution having sizes that match particles within a particle size distribution of combustion particles removed from the combustion exhaust stream.

[0121] The first atomizer and / or the second atomizer can include a plurality of nozzles configured to produce droplets.

[0122] The method can include supplying an atomizing liquid and an atomizing gas to a plurality of nozzles to generate droplets.

[0123] The method can include arranging a plurality of nozzles in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets from each nozzle with a consistent droplet size distribution.

[0124] The method can include configuring a plurality of nozzles to produce droplets with different droplet size distributions from each nozzle.

[0125] The method can include arranging a plurality of nozzles into nozzle groups, each nozzle group in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets having a consistent droplet size distribution from each nozzle group.

[0126] The method can include arranging each group of nozzles in series with a source of atomizing liquid and a source of atomizing gas to produce droplets having a different droplet size distribution from each nozzle in the group.

[0127] The method can include disposing a plurality of nozzles in series with a source of atomizing liquid and a source of atomizing gas to produce droplets from each nozzle having a different droplet size distribution.

[0128] The method can include providing a source of atomizing liquid at one end of the series and a source of atomizing gas at the other end of the series to produce droplets having different droplet size distributions from each nozzle.

[0129] The method may include arranging multiple nozzles to generate droplets of different sizes at different locations in the discharge stream.

[0130] The method can include orienting the nozzle to produce droplets that travel upstream, downstream, and / or across the atomizer.

[0131] The method can include orienting the nozzle to produce droplets that travel both upstream and downstream of the atomizer.

[0132] The method may include orienting the nozzle to produce droplets traveling in a direction opposite to the direction of the combustion exhaust flow.

[0133] The method may include supplying the first atomizer and / or the second atomizer with nebulizing gas at up to 300 liters per minute, preferably up to 250 liters per minute (measured from a flow device set at 0°C).

[0134] The method may include supplying the first atomizer and / or the second atomizer with an atomizing gas at a pressure of up to 10 bar, preferably up to 6 bar.

[0135] The method may include supplying the first atomizer and / or the second atomizer with up to 30 litres per hour, preferably up to 22 litres per hour of spray liquid.

[0136] The method may comprise supplying the first atomizer and / or the second atomizer with spray liquid at a pressure of up to 2 bar, preferably up to 1.5 bar.

[0137] The atomizing gas may consist of nitrogen and / or compressed dry air, and the atomizing liquid may consist of water.

[0138] The first atomizer can include at least one nozzle, and the second atomizer can include at least one nozzle.

[0139] The first atomizer may comprise at least six nozzles arranged in three parallel groups with two nozzles for the source of atomizing liquid and two for the source of atomizing gas.

[0140] The first atomizer may include at least seven nozzles arranged in parallel with a source of atomizing liquid and a source of atomizing gas.

[0141] The method can include conveying the combustion exhaust stream with the droplets from the first atomizer towards a second atomizer to coalesce at least some of the droplets and at least some of the exhaust particles.

[0142] According to a fifth aspect, a method is provided, the method including: determining a particle size of combustion particles removed from a combustion exhaust flow from an abatement chamber of an abatement apparatus that processes an exhaust flow from a semiconductor processing tool; and configuring a first atomizer located downstream of the abatement chamber to generate droplets having a droplet size based on the particle size of the combustion particles removed from the combustion exhaust flow.

[0143] The method can include configuring a second atomizer located downstream of the first atomizer to produce droplets having a droplet size based on a particle size of combustion particles removed from the combustion exhaust stream.

[0144] The method can include disposing a quench spray section upstream of the first atomizer and disposing a spray nozzle for scrubbing the water-soluble gas upstream of the second atomizer. Typically, the method can include disposing the quench spray section in a quenching stage downstream of the abatement chamber. Typically, the method can include disposing spray nozzles in a packed tower downstream of the first atomizer and upstream of the second atomizer.

[0145] The method can include disposing a first atomizer downstream of the quenching stage.

[0146] The method can include positioning a first atomizer toward an inlet of the packed tower.

[0147] The method can include positioning a second atomizer toward the outlet of the packed tower.

[0148] The method may include disposing a second atomizer upstream of one of the cyclone stage and the mist filter.

[0149] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution based on a particle size distribution of exhaust particles removed from the combustion exhaust stream.

[0150] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size distribution that overlaps with a particle size distribution of combustion particles removed from the combustion exhaust stream.

[0151] The method can include configuring the first atomizer and the second atomizer to produce droplets having a droplet size distribution that matches the particle size distribution of combustion particles removed from the combustion exhaust stream.

[0152] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size that is up to 200 times, preferably up to 20 times, the particle size of the exhaust particles removed from the combustion exhaust stream.

[0153] The method can include configuring the first atomizer and / or the second atomizer to produce droplets having a droplet size that is between 20 and 50 times the particle size of the exhaust particles removed from the combustion exhaust stream.

[0154] The method can include configuring the first atomizer and / or the second atomizer to produce droplets within a droplet size distribution having sizes that match particles within a particle size distribution of combustion particles removed from the combustion exhaust stream.

[0155] The first atomizer and / or the second atomizer can include a plurality of nozzles configured to produce droplets.

[0156] The method can include supplying an atomizing liquid and an atomizing gas to a plurality of nozzles to generate droplets.

[0157] The method can include arranging a plurality of nozzles in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets from each nozzle with a consistent droplet size distribution.

[0158] The method can include configuring a plurality of nozzles to produce droplets with different droplet size distributions from each nozzle.

[0159] The method can include arranging a plurality of nozzles into nozzle groups, each nozzle group in parallel with a source of atomizing liquid and a source of atomizing gas to produce droplets having a consistent droplet size distribution from each nozzle group.

[0160] The method can include arranging each group of nozzles in series with a source of atomizing liquid and a source of atomizing gas to produce droplets having a different droplet size distribution from each nozzle in the group.

[0161] The method can include disposing a plurality of nozzles in series with a source of atomizing liquid and a source of atomizing gas to produce droplets from each nozzle having a different droplet size distribution.

[0162] The method can include providing a source of atomizing liquid at one end of the series and a source of atomizing gas at the other end of the series to produce droplets having different droplet size distributions from each nozzle.

[0163] The method may include arranging multiple nozzles to generate droplets of different sizes at different locations in the discharge stream.

[0164] The method can include orienting the nozzle to produce droplets that travel upstream, downstream, and / or across the atomizer.

[0165] The method can include orienting the nozzle to produce droplets that travel both upstream and downstream of the atomizer.

[0166] The method may include orienting the nozzle to produce droplets traveling in a direction opposite to the direction of the combustion exhaust flow.

[0167] The method may include supplying the first atomizer and / or the second atomizer with nebulizing gas at up to 300 liters per minute, preferably up to 250 liters per minute (measured from a flow device set at 0°C).

[0168] The method may include supplying the first atomizer and / or the second atomizer with an atomizing gas at a pressure of up to 10 bar, preferably up to 6 bar.

[0169] The method may include supplying the first atomizer and / or the second atomizer with up to 30 litres per hour, preferably up to 22 litres per hour of spray liquid.

[0170] The method may comprise supplying the first atomizer and / or the second atomizer with spray liquid at a pressure of up to 2 bar, preferably up to 1.5 bar.

[0171] The atomizing gas may consist of nitrogen and / or compressed dry air, and the atomizing liquid may consist of water.

[0172] The first atomizer can include at least one nozzle, and the second atomizer can include at least one nozzle.

[0173] The first atomizer may comprise at least six nozzles arranged in three parallel groups with two nozzles for the source of atomizing liquid and two for the source of atomizing gas.

[0174] The first atomizer may include at least seven nozzles arranged in parallel with a source of atomizing liquid and a source of atomizing gas.

[0175] The method can include conveying the combustion exhaust stream with the droplets from the first atomizer towards a second atomizer to coalesce at least some of the droplets and at least some of the exhaust particles.

[0176] 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.

[0177] Where features of a device are described as operable to provide a certain functionality, this should be understood to include features of a device that provide that functionality or that are adapted or configured to provide that functionality.

[0178] Embodiments of the present invention are described in detail below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0179] [Figure 1] 1 illustrates an abatement device according to one embodiment. [Figure 2] An example of an atomizer configuration is shown. [Figure 3] 1 is a graph showing total nitrogen flow through the atomizer in liters / minute versus total powder removal (measured with the flow equipment set at 0° C.). [Figure 4] 1 is a graph showing the aerodynamic diameter of particles in μm at the 50% impactor cut point for normalized sample powders collected from the exhaust. [Figure 5] 1 is a graph of particle removal efficiency percentage versus time. [Figure 6] The various atomizer configurations referred to in FIG. 5 are shown. [Figure 7] 1 shows a comparison of results from a gravimetric test setup. [Figure 8] 1 is a graph showing the aerodynamic diameter of particles in μm at the 50% impactor cut point for an average sample powder collected from the exhaust. DETAILED DESCRIPTION OF THE INVENTION

[0180] Before describing the embodiments in more detail, an overview is provided below. The embodiments present a configuration in which liquid droplets are generated and introduced into the exhaust stream downstream of the abatement chamber. These droplets bond with or attach to typical solid particles in the exhaust stream, helping to capture or entrain these particles in the fluid within the abatement device. The adhesion of liquid droplets to particles increases as the difference in relative size between the droplets and the particles decreases. Additionally, in environments where particles and liquid droplets can interact, increasing the residence time of particles in the exhaust stream helps increase the probability of adhesion between the droplets and the particles, and further increasing the likelihood of coalescence between other droplets and particles helps increase their mass and thus the likelihood of the particles being entrained in the abatement device fluid. Thus, providing droplets of an appropriate size to adhere to particles in the exhaust stream can entrain the particles within the abatement device (and remove them from the exhaust stream exiting the abatement device). This results in a reduction of particles in the exhaust stream and a cleaner environment. Similarly, providing an opportunity for particles and liquid droplets to coalesce also helps to entrain particles within the abatement device.

[0181] Abatement device FIG. 1 illustrates an abatement apparatus 10 according to one embodiment. An abatement chamber 20 is provided that receives an exhaust stream 30 from a semiconductor processing tool (not shown). As described above, the exhaust stream 30 can include gases and particulate matter. The abatement chamber 20 typically comprises a small-hole burner, direct-fire burner, electrically heated thermal treatment unit, or plasma chamber, as needed, to thermally and chemically ablate the exhaust stream 30 and produce a combustion exhaust stream 30'. The combustion exhaust stream 30' contains particles desired to be removed. Typically, the goal is to remove 90% of particles having a particle size less than 2.5 microns. Downstream of the abatement chamber 20 is a dam stage 50, in which the combustion exhaust stream 30' passes through a conduit surrounded by a flowing water dam. Downstream of the dam stage 50 is a quench stage 60, which injects water transversely to the flow of the combustion exhaust stream 30'. Downstream of the quench stage 60 is a tank 70, which serves as a reservoir for the water in the abatement system 10 and through which the combustion exhaust stream 30' flows. Downstream of the tank 70 is a lower atomizer 80, which generates droplets through which the combustion exhaust stream 30' flows to aid in the removal of particles of a specific size suspended in the combustion exhaust stream 30'. The droplets adhere to particles of the same size, causing them to fall into a water bath due to their increased mass. Other smaller particles agglomerate in the exhaust stream 30'', as described in more detail below. Downstream of the lower atomizer 80 is a packed tower 90. The packed tower 90 typically contains pall rings, which fill the packed tower 90 and are rewetted by water that flows downward from the top of the packed tower 90, against the flow of the agglomerated exhaust stream 30'', through the lower atomizer 80, and into the tank 70 for recirculation. The water in tank 70 is recycled to packed tower 90, dam stage 50, and quench stage 60. Downstream of packed tower 90 is upper atomizer 100, which, as will be explained in more detail below, produces droplets through which the coagulated discharge stream 30'' flows to aid in removing the mostly coagulated and grown particles suspended within the coagulated discharge stream 30''.Downstream of the upper atomizer 100 is a cyclone stage 110, which may include one or more cyclones or mist pads that receive the coagulated discharge stream 30'' and aid in removing suspended particles / water / moisture within the coagulated discharge stream 30'' to produce a treated discharge stream 30'''. Downstream of the cyclone stage 110 is a packed tower lid 120, which includes a discharge system through which the treated discharge stream 30''' is discharged to an extraction facility.

[0182] In operation, exhaust stream 30 (containing gases and possibly solid components or particles) is received by abatement chamber 20 at the inlet and discharged at the outlet as combustion exhaust stream 30' (also containing gases and solid components or particles) into dam stage 50. Combustion exhaust stream 30' passes through dam stage 50 and quench stage 60, where it is cooled. The quench nozzle removes a proportion of the particles generated from the chemical abatement process. The cooled combustion exhaust stream 30' exits quench stage 60 and travels through tank 70 to lower atomizer 80.

[0183] The lower atomizer 80 produces water droplets that attach to particles in the combustion exhaust stream 30' to produce a cohesive exhaust stream 30''. The cohesive exhaust stream 30'' now contains gaseous and solid components or particles, combined particles and droplets, and cohesive particles and droplets. When they increase to a sufficient mass, they then fall out of the suspension of the cohesive exhaust stream 30''.

[0184] As the agglomerated discharge stream 30'' passes through the packed tower 90, some of the gaseous components dissolve in the water flowing through the packed tower 90. In addition, some of the particles, particle and droplet combinations, and agglomerated particles in the agglomerated discharge stream 30'' adhere to wetted surfaces within the packed tower 90 and are washed away by the packed tower spray. In addition, the size of the agglomerated particles in the agglomerated discharge stream 30'' increases as they coalesce as they travel through the packed tower 90 from the lower atomizer 80 to the upper atomizer 100. When they increase to a sufficient mass, they then drop out of the suspension of the agglomerated discharge stream 30''.

[0185] The coagulated discharge stream 30'' passes through the upper atomizer 100, which also produces droplets. As some of these droplets pass through the upper atomizer 100, they combine with some of the particles, combined particles and droplets, and coagulated particles still present in the coagulated discharge stream 30''. When they increase in mass sufficiently, they then fall out of the suspension of the coagulated discharge stream 30''. In addition, some of the droplets produced by the upper atomizer 100 fall into the packed tower 90 and interact with the coagulated discharge stream 30'' passing through the packed tower 90.

[0186] In this way, the lower atomizer 80 helps remove a predetermined percentage of the particles in the combustion exhaust stream 30′ by producing droplets that attach to these particles and, either directly or by agglomeration with other particles, increase their mass so that they move against the flow and fall toward the tank 70. Similarly, some of the remaining particles, bound particles and droplets, and agglomerated particles can be directly captured by wetted surfaces within the packed tower 90. The probability of such attachment or falling of suspended matter increases as the droplets and particles move through the packed tower 90 because they become more bound and agglomerated as they move through the packed tower 90. Any remaining particles, bound particles and droplets, and agglomerated particles are then, under the influence of the additional influx of droplets from the upper atomizer 100, again combine with a predetermined percentage of the particles and / or agglomerated particles still remaining in the agglomerated exhaust stream 30″. Some of these return to the packed tower 90 or move to the cyclone 110. Again, as the remaining particles, combined particles and droplets, and agglomerated particles move towards the cyclone stage 110, the proportion of agglomerated particles increases, as does the mass of the agglomerated particles. This improves the performance of the upper atomizer 100, as any particles not removed by the lower atomizer 80 are immediately separated by the upper atomizer 100. The cyclone stage 110 removes the particles / water / moisture carried by the discharge stream 30''. As a result, the treated discharge stream 30''' exiting the packed tower lid 120 has a very low fines content.

[0187] In one experiment, a four-inlet abatement system 10 was fed with 0.25 liters per minute of silane at 1 bar. The silica powder produced from the combustion of silane was then measured using an electric low-pressure impactor (ELPI+®), which provides particle size analysis for real-time particle measurement. The atomizer nozzle uses nitrogen or air to break up the water into smaller droplets. The higher the N2 / air feed rate and pressure to the atomizing nozzle, the smaller the water droplets produced. In the experiments described herein, the nozzle used was a Spraying Systems Company® atomizing spray mechanism SU26. The SU26 mechanism consists of a fluid cap 60100 and an air cap 140-6-37-70° attached to a standard air atomizer nozzle body. The upper atomizer 100 is mounted above the packed tower 90 and has a spool that splits a single supply of water and nitrogen into two SU26 nozzles facing the packed tower 90 and one SU26 nozzle facing the cyclone stage 110 to allow wetting of the cyclone stage 110 and improve its efficiency, as shown in Figure 2. The lower atomizer 80 is mounted below the packed tower 90 and has a spool that splits the water and nitrogen into three SU26 nozzles directed toward the tank 70.

[0188] The detailed configuration and operation of the nozzle can be tailored to suit the conditions within the system. For example, an assessment or determination of the size, size distribution, and quantity or proportion of expected particles can be made for the abatement system. Additionally, it can be determined how they are expected to be distributed at different locations within the abatement system. The atomizer can then be positioned, configured, and operated to produce droplets of the appropriate size, size-distribution, and quantity for those expected particles.

[0189] Figure 3 is a graph of the total nitrogen flow through the atomizer (in liters / minute) versus the overall percent powder removal from the system, showing the performance of the upper atomizer 100 and the lower atomizer 80 individually when operated with nitrogen flows varied between 150 and 250 liters / minute. Point 1 refers to the stainless steel nozzle of the upper atomizer 100, point 2 refers to the stainless steel nozzle of the lower atomizer 80, and point 3 refers to the plastic nozzle of the lower atomizer 80. The total nitrogen supply to the spray spool (supplied at 6 bar pressure) was varied to investigate the effect on droplet size. The graph shows experiments where the upper atomizer 100 and the lower atomizer 80 were operated independently. As can be seen, the performance of the upper atomizer 100 remains fairly constant as the nitrogen flow rate to the three nozzles is increased (and the water flow rate is decreased) (increasing the nitrogen flow rate to the upper atomizer does not result in a significant improvement in particle removal efficiency). Supplying 6 bar nitrogen at 100 liters per minute to the upper atomizer 100 resulted in a 66% powder removal rate, compared with 70% at 250 liters per minute. Therefore, supplying 180 liters per minute of 6 bar nitrogen and 1 liter per minute of 1.5 bar water to the upper atomizer 100 would be appropriate. Testing has shown that orienting the upper atomizer 100 so that the three nozzles face toward the packed tower 90 and oppose the flow of the coagulated discharge stream 30'' increases powder removal. The lower atomizer 80 also demonstrated lower powder removal rates than the upper atomizer 100, except for a nitrogen flow of 250 liters per minute. Furthermore, the nozzle material does not affect powder removal, as plastic nozzles performed comparable to stainless steel nozzles.

[0190] [Table 1]

[0191] Table 1 shows the silica powder removal rate for different atomizer positions (Dual ATSP has both atomizers activated, Top ATSP has the upper atomizer 100 activated, and Bottom ATSP has the lower atomizer 80 activated). As can be seen, the optimal configuration achieves a powder removal rate of 76%. This is achieved with both the upper atomizer 100 and the lower atomizer 80 activated, with the upper atomizer 100 supplied with 250 liters per minute of nitrogen at 6 bar and approximately 22 liters per hour of water at 1.5 bar, and the lower atomizer 80 supplied with 250 liters per minute of nitrogen at 6 bar and approximately 25 liters per hour of water at 1.5 bar.

[0192] However, the best configuration, when tested gravimetrically (two replicates), resulted in an average performance of 82.1% powder removal, rather than the 76% powder removal shown in Table 1.

[0193] Figure 4 is a graph of the aerodynamic particle size in μm at the 50% impactor cut point versus the normalized mass (%) of sample powder collected from the exhaust. It shows the normalized mass of particle size distribution and compares the results of various atomizer configurations. Line 1 shows the performance when the atomizer is inactive, but the abatement system 10, including the abatement chamber 20, dam stage 50, quench stage 60, tank 70, and packed tower 90, is on, and the exhaust flow 30 is co-flowing. Line 2 shows the performance of the abatement system 10 with the addition of a lower atomizer 80 when operating at 250 liters per minute of nitrogen. Line 3 shows the performance of the abatement system 10 with the addition of an upper atomizer 100 operating at 250 liters per minute of nitrogen. Line 4 shows the operation of the abatement system 10 with both the lower atomizer 80 and the upper atomizer 100 when operating at 250 liters per minute of nitrogen. The results show that when the upper atomizer 100 is used, fewer large particles (0.6 microns) are measured in the exhaust compared to when the upper atomizer 100 is not activated. This may be the result of trapping (i.e., removing) the larger particles, resulting in a larger proportion of smaller particles appearing in the exhaust, although there are more particles with a diameter of 0.225 microns. The lower atomizer 80 exhibits an increased concentration of larger particles (particle sizes 0.255 microns and larger) emitted from the exhaust. With both the lower atomizer 80 and the upper atomizer 100 activated, the particle size distribution appears to shift toward smaller particle sizes. Here, an increased concentration of 0.154 and 0.255 micron particles is observed in the exhaust, but this is also due to a normalized distribution, and the absolute number of smaller particles decreases, as demonstrated in Table 1 and through gravimetric testing.

[0194] FIG. 5 is a graph of particle removal efficiency versus time, showing the impact that the packed tower 90 has on performance for a configuration utilizing both the lower atomizer 80 and the upper atomizer 100. The test was conducted over a two-hour period. Line 1 represents the results when both the lower atomizer 80 and the upper atomizer 100 are operating, but the fluid in the tank 70 already contains a lot of powder (the water is white). Line 2 represents the results when both the lower atomizer 80 and the upper atomizer 100 are operating, but the liquid in the tank 70 is clean. However, this shows the same trends as the configurations shown for line 3 (omitting the pall ring and spray) and line 4 (omitting only the pall ring). However, the effect of removing the pall ring and / or spray is to dramatically reduce the surface area within the packed tower 90 that affects the removal of water-soluble gases from the coagulated exhaust stream 30″. It can be seen that the packed tower spray is a water-only spray that produces droplets that are significantly larger in size than the particles in the coagulated discharge stream 30'', and therefore the presence of the pall rings and spray in the packed tower 90 has little effect on the removal of particles from the coagulated discharge stream 30''.

[0195] FIG. 6 illustrates various configurations mentioned in FIG. 5. Specifically, FIG. 6A illustrates a configuration for lines 1, 2, and 4, FIG. 6B illustrates a configuration for line 3, and FIG. 6C illustrates a configuration for line 5. As can be seen from FIG. 5, when the configuration shown in FIG. 6C is adopted, in which the packed tower 90 is located downstream of both the lower atomizer 80 and the upper atomizer 100, the powder removal rate decreases by approximately 10%. This suggests that spatial separation of the atomizers, with or without a pall ring and packed tower spray, aids in particle removal. While not intending to be limited by theory, this suggests that the lower atomizer 80 removes smaller particles or promotes agglomeration of smaller particles. As the agglomerated discharge stream 30″ passes through the packed tower 90, the particles agglomerate and become larger. As such agglomeration continues to reach a certain size (e.g., 0.25 microns or larger), the upper atomizer 100 becomes more effective at removing these particles, and as such agglomeration continues, the cyclone stage 110 similarly becomes more effective at removing these particles. This makes the dual atomizer configuration more effective since there are two particle removal stages after the quench stage 60. This also means that the space in the packed tower helps make the dual atomizer configuration more effective at removing particles.

[0196] Experimental data indicates that, when operating at a throughput of 500 lpm and a silane flow of 0.25 lpm, for a packed tower configuration such as that shown in FIG. 6 (250 mm diameter, 117 cm total height), powder removal performance does not increase beyond that shown for the configuration of FIG. 6(c) (in which the lower atomizer 80 and upper atomizer 100 are adjacent) until the distance between the lower atomizer 80 and the upper atomizer 100 is increased to at least 17.5 cm. This indicates that particle agglomeration and resulting particle growth as they move from the lower atomizer 80 to the upper atomizer 100 helps improve the particle removal performance of the upper atomizer 100. Additionally, orienting the spray nozzles opposite the main direction of flow through the packed tower helps slow the flow through the tower, thereby increasing residence time and further improving particle removal.

[0197] As mentioned above, data collected using the ELPI+® device was verified gravimetrically, but here the ELPI+® device was operated with a high-efficiency particulate air (HEPA) filter installed after a cyclone capable of removing particles larger than 10 microns at the sampling line, sampled 60 cm above the packed tower lid 120. The results are shown in Figure 7, which shows a comparison of results from a gravimetric test setup. Column A shows the percentage of powder (particles) removed without the use of the lower atomizer 80 and upper atomizer 100 (powder removal from the abatement system). Column B shows the percentage of powder removed when both the lower atomizer 80 and upper atomizer 100 were present. Column C shows an alternative configuration using a single seven-nozzle lower atomizer 80.

[0198] A single seven-nozzle lower atomizer 80 gravimetrically captured 77.4% of the powder produced. The seven-nozzle atomizer is an atomizer spool consisting of seven SU26 nozzles, each individually fed with 100 liters per minute of nitrogen at 6 bar and 2.5 liters per hour of water at 1.5 bar from seven inlet feeds. This configuration was achieved through testing (visual judgment) that involved varying the gas flow rate fed to one nozzle to identify the optimum ratio of nitrogen to water before the water supply was blocked. This ratio was then applied to all seven nozzles to determine how creating more equal-sized water droplets affected powder removal efficiency.

[0199] [Table 2]

[0200] Table 2 shows the droplet size measured from the nozzle at a distance of 0.15 meters from the nozzle (according to the nozzle supplier Spraying systems®).

[0201] definition -D32 - Sauter median diameter, this value is the droplet size that best represents the entire spray, i.e. the ratio of the volume to the surface area of ​​a droplet of this size is the same as the ratio of the volume to the surface area of ​​the entire spray. -D10 is the straight (arithmetic) mean droplet size -DV0.5 - volume median diameter, the volume of the spray is 50% smaller than this size and 50% larger than this value. - DV0.9 - 90% of the spray volume has a droplet size smaller than or equal to this value.

[0202] [Table 3]

[0203] Table 3 shows the results when varying the number of nozzles activated. As can be seen, the best results are obtained using a 7-nozzle atomizer. At a Sauter median diameter of 28 microns, 76.95% of the powder is removed.

[0204] Figure 8 shows the normalized particle distribution for this test, plotting the aerodynamic diameter in μm at the 50% impactor cut point against the normalized mass of the sample powder collected from the exhaust. Line 1 represents no atomizer, line 2 represents one nozzle, line 3 represents three nozzles, line 4 represents five nozzles, and line 5 represents seven nozzles. Comparing the particle size distributions without and with atomizers shows that the particle size distribution shifts to the left as the number of atomizers increases. Therefore, generating droplets with a Sauter median diameter of 28 μm removes particles larger than 0.3819 μm. Additionally, nozzle proximity may also be a factor, suggesting shearing to smaller droplet sizes or agglomeration to larger droplet sizes.

[0205] Without intending to be bound by theory, it has been observed that the closer the droplet size is to the particles in the exhaust stream, the more effective the particle removal from the exhaust stream. It is believed that droplets and particles with similar sizes tend to adhere more easily. Droplets and particles do not necessarily have to be the same size; droplets may adhere even if they are many times larger than the particle. For example, particles with a Sauter median diameter of 28 microns are believed to effectively adhere to particles larger than 0.2555 microns. Therefore, droplets 200 times larger than the particle may adhere to these particles. Therefore, generating droplets of similar size to the particles would enhance particle removal. It has also been observed that because particles will have a specific size distribution in combustion exhaust streams, it is advantageous for droplets to have a similar size distribution to maximize size correlation. This can be achieved by using different nozzles to generate droplets of different sizes and size distributions. Similarly, as demonstrated with the seven-nozzle atomizer, an extremely large amount of droplets relative to the number of particles can increase droplet-particle adhesion, likely due to a higher statistical probability of droplet-particle collision and adhesion. Furthermore, even when extremely small particles, even if combined with droplets, have masses that are too small to fall by gravity relative to the flow of the exhaust stream, the combined droplets and particles have been observed to tend to adhere to surfaces within the packed tower and to agglomerate with other droplets and / or particles and / or combined droplets and particles, thus growing in size as they travel through the packed tower 90. This increases the likelihood that they will be effectively entrained within the packed tower 90 or combine with additional droplets provided by the upper atomizer 100 to achieve a mass that overcomes the combustion exhaust stream due to the effects of gravity, and / or improve their removal from the combustion exhaust stream by the upper atomizer 100.

[0206] In one experiment, the typical measured particle size at the upper atomizer (without the dual atomizer) was about 433 nm. The measured droplet size was about 16.2-63.7 μm, measured at a distance of 15 cm from the spray nozzle (however, the maximum space between the upper atomizer and the packed tower is 15 cm, and the maximum space between the lower atomizer and the tank water level is 15 cm, so the droplets will be slightly smaller than this, and therefore it would be useful to measure them less than 15 cm from the nozzle). This indicates that the droplet size is 20 to 50 times the particle size (37 times for 16 μm droplets).

[0207] Thus, in some embodiments, the particle size of the droplets is selected based on the expected size of the particles in the output stream. The droplets need not exactly match the particle size, but can often be up to 200 times the size of the particles, typically between 20 and 50 times, while still promoting adhesion and coalescence between the droplets and the particles. Furthermore, if the expected size distribution of the particles is known, the size distribution of the droplets can be controlled to match at least a portion of that size distribution to ensure that an appropriate amount of droplets of the appropriate size (often relative) is available.

[0208] Although exemplary embodiments of the present invention are disclosed in detail herein with reference to the accompanying drawings, it should be understood that the present invention is not limited to the precise embodiments and that various changes and modifications can be made thereto 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]

[0209] 10 Abatement equipment 20 Abatement chamber 30 Discharge flow 30' combustion exhaust flow 30'' Coagulated Discharge Flow 30'' treated discharge flow 50 Dam Stage 60 Quench Stage 70 Tank 80 Lower atomizer 90 Packed tower 100 Upper atomizer 110 Cyclone Stage 120 Packed tower lid

Claims

1. A scavenging chamber that processes the discharge flow from a semiconductor processing tool to provide a combustion discharge flow containing discharge particles, A weir stage located downstream of the abatement chamber, wherein the combustion discharge flow passes through a conduit surrounded by flowing water, A quench stage located downstream of the aforementioned weir stage, wherein a quench spray section is located on the quench stage, A first atomizer located downstream of the quench stage, configured to produce droplets having a droplet size based on the particle size of the exhaust particles removed from the combustion exhaust flow, the first atomizer comprising a plurality of nozzles configured to produce the droplets, the plurality of nozzles configured to produce droplets having different droplet size distributions from each nozzle, A packed tower located downstream of the first atomizer, wherein a spray nozzle is arranged inside the packed tower, Equipped with, The aforementioned plurality of nozzles are supplied with spray liquid and spray gas to generate droplets, The plurality of nozzles are arranged in a plurality of groups, and each group is arranged in parallel with the spray liquid supply source and the spray gas supply source in order to generate droplets having a consistent droplet size distribution from each group of nozzles. The nozzles in each group are arranged in series with the spray liquid supply source and the spray gas supply source, and droplets with different droplet size distributions are generated from each nozzle within that group. A pollution control device in which nozzles configured to produce smaller droplets are positioned toward the center of the inlet of the packed column, and nozzles configured to produce larger droplets are positioned toward the end of the inlet of the packed column.

2. The abatement device according to claim 1, further comprising a second atomizer located downstream of the packed tower.

3. The pollution control device according to claim 2, wherein at least one of the first atomizer and the second atomizer is configured to generate droplets having a droplet size distribution based on the particle size distribution of the discharged particles removed from the combustion discharge flow.

4. The abatement device according to claim 3, wherein at least one of the first atomizer and the second atomizer is configured to generate droplets having a droplet size distribution that overlaps with the particle size distribution of the discharged particles removed from the combustion discharge flow.

5. The abatement device according to claim 3 or 4, wherein at least one of the first atomizer and the second atomizer is configured to produce droplets having a droplet size distribution that matches the particle size distribution of the discharged particles removed from the combustion discharge flow.

6. The abatement device according to any one of claims 2 to 5, wherein at least one of the first atomizer and the second atomizer is configured to generate droplets having a droplet size up to 200 times the particle size of the discharge particles to be removed from the combustion discharge flow.

7. The abatement device according to claim 6, wherein the droplets have a droplet size that is up to 20 times the particle size of the discharge particles removed from the combustion discharge flow.

8. The abatement device according to any one of claims 3 to 5, wherein at least one of the first atomizer and the second atomizer is configured to generate droplets in the droplet size distribution having a size that matches the particles in the particle size distribution of the discharge particles to be removed from the combustion discharge flow.

9. The abatement device according to any one of claims 2 to 8, wherein the second atomizer comprises a plurality of nozzles configured to generate the droplets.

10. The abatement device according to claim 9, wherein the plurality of nozzles of the second atomizer are configured to generate droplets having different droplet size distributions from each of the nozzles.

11. The abatement device according to claim 9 or 10, wherein the plurality of nozzles of the second atomizer are arranged in series with the source of the spray liquid and the source of the spray gas, and droplets having different droplet size distributions are generated from each of the nozzles.

12. The abatement device according to any one of claims 9 to 11, wherein the plurality of nozzles of the first atomizer and the second atomizer are arranged to generate droplets of different sizes at different positions in the discharge flow.

13. The abatement device according to any one of claims 9 to 12, wherein the nozzles of the first atomizer and the second atomizer are oriented to generate droplets that travel in the opposite direction to the combustion exhaust flow.

14. A detoxification chamber that processes the discharge flow from a semiconductor processing tool to provide a combustion discharge flow containing combustion particles, A weir stage located downstream of the abatement chamber, wherein the combustion discharge flow passes through a conduit surrounded by flowing water, A quench stage located downstream of the aforementioned weir stage, wherein a quench spray section is located on the quench stage, A first atomizer located downstream of the quench stage, configured to generate droplets that capture at least a portion of the combustion particles, A packed tower located downstream of the first atomizer, wherein a spray nozzle is arranged inside the packed tower, A second atomizer located downstream of the packed column, configured to generate droplets that capture at least a portion of the combustion particles, Equipped with, At least one of the first atomizer and the second atomizer comprises a plurality of nozzles configured to generate the droplets, The plurality of nozzles are configured to generate droplets having different droplet size distributions from each nozzle. The plurality of nozzles are supplied with spray liquid and spray gas to generate the droplets, The plurality of nozzles are arranged in a plurality of groups, and each group is arranged in parallel with the spray liquid supply source and the spray gas supply source in order to generate droplets having a consistent droplet size distribution from each group of nozzles. The nozzles in each group are arranged in series with the supply source of the spray liquid and the supply source of the spray gas, and each nozzle in the group generates droplets having a different droplet size distribution. A pollution control device in which nozzles configured to produce smaller droplets are positioned toward the center of the inlet of the packed column, and nozzles configured to produce larger droplets are positioned toward the end of the inlet of the packed column.

15. The steps include receiving a combustion discharge flow containing combustion particles from a pollution chamber of a pollution control device that processes the discharge flow from a semiconductor processing tool, A step of positioning a weir stage downstream of the abatement chamber, wherein the combustion discharge flow passes through a conduit surrounded by flowing water in the weir stage, A step of positioning a quench stage downstream of the weir stage, wherein a quench spray section is located on the quench stage, A step of removing combustion particles from the combustion exhaust flow using a first atomizer located downstream of the quench stage, configured to produce droplets having a droplet size based on the particle size of the combustion particles to be removed from the combustion exhaust flow, wherein the first atomizer comprises a plurality of nozzles configured to produce the droplets, the plurality of nozzles configured to produce droplets having a different droplet size distribution from each nozzle, and the plurality of nozzles are supplied with a spray liquid and a spray gas to produce the droplets. The steps include positioning a spray nozzle in a packed tower located downstream of the first atomizer, Includes, The plurality of nozzles are arranged in a plurality of groups, and each group is arranged in parallel with the spray liquid supply source and the spray gas supply source in order to generate droplets having a consistent droplet size distribution from each group of nozzles. The nozzles in each group are arranged in series with the supply source of the spray liquid and the supply source of the spray gas, and each nozzle in the group generates droplets having a different droplet size distribution. A method of abating in which a nozzle configured to produce smaller droplets is positioned toward the center of the inlet of the packed column, and a nozzle configured to produce larger droplets is positioned toward the end of the inlet of the packed column.

16. The steps include receiving a combustion discharge flow containing combustion particles from a pollution chamber of a pollution control device that processes the discharge flow from a semiconductor processing tool, A step of positioning a weir stage downstream of the abatement chamber, wherein the combustion discharge flow passes through a conduit surrounded by flowing water in the weir stage, A step of positioning a quench stage downstream of the weir stage, wherein a quench spray section is located on the quench stage, A step of removing combustion particles from the combustion exhaust flow using a first atomizer located downstream of the quench stage, configured to generate droplets that capture at least a portion of the combustion particles, and a second atomizer located downstream of the first atomizer, configured to generate droplets that capture at least a portion of the combustion particles, wherein at least one of the first atomizer and the second atomizer comprises a plurality of nozzles configured to generate the droplets, the plurality of nozzles being configured to generate droplets having different droplet size distributions from each nozzle, and the plurality of nozzles being supplied with a spray liquid and a spray gas to generate the droplets. The steps include positioning a spray nozzle in a packed tower located downstream of the first atomizer and upstream of the second atomizer, Includes, The plurality of nozzles are arranged in a plurality of groups, and each group is arranged in parallel with the spray liquid supply source and the spray gas supply source in order to generate droplets having a consistent droplet size distribution from each group of nozzles. The nozzles in each group are arranged in series with the supply source of the spray liquid and the supply source of the spray gas, and each nozzle in the group generates droplets having a different droplet size distribution. A method of abating in which a nozzle configured to produce smaller droplets is positioned toward the center of the inlet of the packed column, and a nozzle configured to produce larger droplets is positioned toward the end of the inlet of the packed column.

17. A step of determining the particle size of combustion particles to be removed from the combustion discharge flow from the abatement chamber of a plaque removal device that processes the discharge flow from a semiconductor processing tool, A step of positioning a weir stage downstream of the abatement chamber, wherein the combustion discharge flow passes through a conduit surrounded by flowing water in the weir stage, A step of positioning a quench stage downstream of the weir stage, wherein a quench spray section is located on the quench stage, A step of configuring a first atomizer located downstream of the quench stage to generate droplets having a droplet size based on the particle size of the combustion particles removed from the combustion exhaust flow, wherein the first atomizer comprises a plurality of nozzles configured to generate the droplets, the plurality of nozzles configured to generate droplets having different droplet size distributions from each nozzle, and the plurality of nozzles are supplied with a spray liquid and a spray gas to generate the droplets, The steps include positioning a spray nozzle in a packed tower located downstream of the first atomizer, Includes, The plurality of nozzles are arranged in a plurality of groups, and each group is arranged in parallel with the spray liquid supply source and the spray gas supply source in order to generate droplets having a consistent droplet size distribution from each group of nozzles. The nozzles in each group are arranged in series with the supply source of the spray liquid and the supply source of the spray gas, and each nozzle in the group generates droplets having a different droplet size distribution. A method of abating in which a nozzle configured to produce smaller droplets is positioned toward the center of the inlet of the packed column, and a nozzle configured to produce larger droplets is positioned toward the end of the inlet of the packed column.

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