KR-102960636-B1 - Flammable gas diluent and method for the same

KR102960636B1KR 102960636 B1KR102960636 B1KR 102960636B1KR-102960636-B1

Abstract

A flammable gas diluter (5) is disclosed for diluting a flow of flammable gas to a concentration below the flammability limit of the flammable gas. The flammable gas diluter (5) comprises: a dilution vessel (10) including an outer envelope defining a longitudinal flow passage from an inlet (11) to an outlet (12); at least one air inlet assembly (16, 17) for guiding a flow of air to the inlet (11) of the dilution vessel (10); a flammable gas inlet (15) arrangement positioned toward the end of the inlet (11) of the dilution vessel (10); and two gas flow generators configured to pump a flow of air to the air inlet (16, 17) assembly, the two gas flow generators being positioned upstream of the flammable gas inlet (15) arrangement. The two gas flow generators are configured to operate as operating and backup gas flow generators. The combustible gas diluent (10) includes two dampers (16A, 17A), one damper (16A, 17A) is connected to each of the gas flow generators, and each of the dampers (16A) is mounted between the corresponding gas flow generator and the dilution container (10). The dampers (16A, 17A) are configured to block the passage between the corresponding gas flow generator and the dilution container (10) when closed, and to open the passage between the gas flow generator and the dilution container (10) when open. The combustible gas diluent (10) includes a control circuit (80) configured to control the opening and closing of the damper (16A), and the control circuit (80) is configured to open the damper (16A, 17A) during the operating mode of the corresponding gas flow generator and to close the damper (16A, 17A) when the corresponding gas flow generator is stopped in standby mode.

Inventors

그린우드 조앤 레이첼

Assignees

에드워즈 리미티드

Dates

Publication Date: 20260507
Application Date: 20210607
Priority Date: 20200612

Claims (11)

In a flammable gas diluter for diluting a flow of flammable gas to a concentration below the flammability limit of the flammable gas, A dilution vessel comprising an outer envelope defining a longitudinal flow path from an inlet to an outlet; At least one air inlet assembly for guiding the flow of air to the inlet of the dilution container; A flammable gas inlet arrangement positioned toward the inlet end of the dilution container; Two gas flow generators configured to pump airflow to the air inlet assembly above — said two gas flow generators are located upstream of the combustible gas inlet device, where said two gas flow generators are configured to operate as an operating gas flow generator and a backup gas flow generator —; Two dampers — one damper is connected to each of the gas flow generators, and each damper is mounted between the corresponding gas flow generator and the dilution vessel, and the damper is configured to block the passage between the corresponding gas flow generator and the dilution vessel when closed and to open the passage between the gas flow generator and the dilution vessel when opened —; and A control circuit configured to control the opening and closing of the damper — the control circuit is configured such that the damper is opened during the operating mode of the corresponding gas flow generator and the damper is closed when the corresponding gas flow generator is stopped in standby mode — comprising A flammable gas diluent for diluting a flow of flammable gas to a concentration below the flammability limit of the flammable gas.
In Article 1, The above control circuit, in response to a signal indicating that the currently operating gas flow generator must be stopped and the gas flow generator currently in standby mode must be started, Control the gas flow generator in standby mode to start, and after a predetermined delay, To control the damper associated with the gas flow generator started above to open Composed of A flammable gas diluent for diluting a flow of flammable gas to a concentration below the flammability limit of the flammable gas.
In Article 2, The above-mentioned predetermined delay includes the time for the gas flow generator in standby mode to reach at least 70% of its normal operating speed. A flammable gas diluent for diluting a flow of flammable gas to a concentration below the flammability limit of the flammable gas.
In Article 2, The above control circuit is configured to control the damper associated with the gas flow generator to be stopped to close after the predetermined delay and to control the gas flow generator to stop. A flammable gas diluent for diluting a flow of flammable gas to a concentration below the flammability limit of the flammable gas.
In Article 1, The above control circuit, in response to a signal indicating that the diluent should be started, Controlling the damper associated with the backup gas flow generator to open and the damper associated with the operating gas flow generator to close, and controlling the backup gas flow generator to start; and Control the above-mentioned operating gas flow generator to start after the set test time; and Controlling the damper associated with the operating gas flow generator to open and the damper associated with the backup gas flow generator to close after a predetermined delay; To control the backup gas flow generator to stop operation Composed of A flammable gas diluent for diluting a flow of flammable gas to a concentration below the flammability limit of the flammable gas.
In a vacuum pumping system for exhausting at least one vacuum chamber within a semiconductor processing tool, A plurality of vacuum pumps for exhausting at least one vacuum chamber; and The apparatus comprises an abatement system for receiving a combustible gas from at least one of the at least one vacuum chambers, wherein the abatement system comprises a combustible gas diluent described in any one of claims 1 to 5. A vacuum pumping system for exhausting at least one vacuum chamber within a semiconductor processing tool.
In Article 6, The above semiconductor processing tool includes an extreme ultraviolet lithography tool, and the above flammable gas includes hydrogen. A vacuum pumping system for exhausting at least one vacuum chamber within a semiconductor processing tool.
In Article 6, A housing for accommodating the plurality of vacuum pumps; and It further includes an air flow duct for receiving air from the above housing, and The air flow duct is fluidly connected to the at least one air inlet assembly to supply air to the combustible gas diluent, so that as a result, air flows through the housing, along the air flow duct, and into the diluent in response to the operation of at least one of the gas flow generators. A vacuum pumping system for exhausting at least one vacuum chamber within a semiconductor processing tool.
A method for controlling the operation of two gas flow generators for supplying a gas flow to a combustible gas diluent described in any one of claims 1 to 5, wherein Controlling the first gas flow generator among the two gas flow generators currently in standby mode to start, while maintaining the damper between the first gas flow generator and the dilution container in a closed position; Controlling the damper associated with the first gas flow generator to open after a predetermined delay A method for controlling the operation of two gas flow generators to supply gas flow to a combustible gas diluent.
In Article 9, Controlling the damper associated with the second gas flow generator to be stopped to close after the predetermined delay; and Additionally comprising controlling the second gas flow generator to stop. A method for controlling the operation of two gas flow generators to supply gas flow to a combustible gas diluent.
In Article 9, The above method, in response to a signal indicating that the diluent should be started, Controlling the damper associated with the backup gas flow generator to open and the damper associated with the operating gas flow generator to close; Controlling the above backup gas flow generator to start; and Controlling the above-mentioned operating gas flow generator to start after a set test time; and Controlling the damper associated with the operating gas flow generator to open after a predetermined delay; Controlling the damper associated with the backup gas flow generator to be closed; and Controlling the backup gas flow generator to stop operation A method for controlling the operation of two gas flow generators to supply gas flow to a combustible gas diluent.

Description

Flammable gas diluent and method for the same The field of the present invention relates to the dilution of flammable gases, and in some embodiments, to vacuum pumping and decontamination systems. There are semiconductor manufacturing processes where the gases to be exhausted and decontaminated are flammable gases such as hydrogen. For example, in lithography, products are manufactured through controlled exposure to a radiation source. In this case, the radiation source is extreme ultraviolet (EUV) radiation. In these processes, increasingly larger amounts of hydrogen are used as a curtain gas to protect optics and mirrors from sputtered tin excited by a laser to emit EUV light from the lithography tools. These processes are performed in a vacuum, and the vacuum system provides the vacuum pressure necessary for these processes to occur and transports the hydrogen for safe decontamination. In many abatement systems, combustible gases removed from the vacuum process chamber are burned to eliminate the gas. This has associated environmental impacts, and typically requires two abatement tools: one operating tool and a backup tool in case the operating tool's burner goes out. This setup is costly in terms of both fuel and space. It would be desirable to provide an alternative method for mitigating flammable gases from the gas stream so that the gas stream can be safely exhausted. A first embodiment is a flammable gas diluter for diluting a flow of flammable gas to a concentration below the flammability limit of said flammable gas, comprising: a dilution vessel including an outer envelope defining a longitudinal flow passage from an inlet to an outlet; at least one air inlet assembly for guiding an air flow to said inlet of said dilution vessel; a flammable gas inlet arrangement positioned toward the inlet end of said dilution vessel; and two gas flow generators configured to pump an air flow to said air inlet assembly ― said two gas flow generators located upstream of said flammable gas inlet arrangement, wherein said two gas flow generators are configured to operate as operating and backup gas flow generators ―; A combustible gas diluent comprises: two dampers—one damper connected to each of the gas flow generators, each damper mounted between the corresponding gas flow generator and the dilution vessel, wherein the dampers are configured to block the passage between the corresponding gas flow generator and the dilution vessel when closed and to open the passage between the gas flow generator and the dilution vessel when opened—and a control circuit configured to control the opening and closing of the dampers—wherein the control circuit is configured to open the dampers during the operating mode of the corresponding gas flow generator and to close the dampers when the corresponding gas flow generator is stopped in standby mode. Flammable gases are difficult to handle and dispose of. For this reason, flammable gases emitted from systems are typically treated by burning them in burners, sometimes using methane as fuel. This impacts the environment, is relatively expensive in terms of fuel and space, and may present reliability issues. Despite the problems associated with handling flammable gases, large amounts can be simply vented into the atmosphere if they can be safely diluted below the flammability limit. Previously, when flammable gases were diluted, they were typically diluted with nitrogen, an inert gas, at pressures above atmospheric pressure. However, in systems with large volumes of flammable gas, the amount of nitrogen required to lower the gas concentration below the flammability level is often prohibitively expensive. Furthermore, operating at higher pressures presents its own inherent problems. Diluting flammable gases appears to be an acceptable and safer alternative to burning the flammable gases as a means of reduction. If the concentration of flammable gases increases, it not only affects safety but may also require shutting down the system where the flammable gases are generated, which can be costly. An embodiment solves this problem with a combustible gas diluent having a supply of air from at least two gas flow generators, each configured to operate in operating mode or as a backup. Thus, one gas flow generator can generate the necessary air flow, while the other serves as a backup in standby mode, ready for use when the operating gas flow generator requires service. One potential problem associated with providing two gas flow generators is the potential leakage path of gas flow out of the dilution system through the non-operating gas flow generator. This can cause pressure fluctuations within the system, triggering an alarm and potentially shutting down the system. Furthermore, flow passing through the gas flow generator in the opposite direction to the operating direction can cause reverse rotation, making it difficult or impossible to start when necessary. This issue was resolved by provid