Patent Application
20080310975
The present invention relates generally to electronic device manufacturing and more particularly relates to methods and systems for abating effluent gases produced in electronic device manufacturing.
Electronic device manufacturing process tools (hereinafter “process tools”) conventionally employ chambers or other suitable apparatus adapted to perform processes (e.g., chemical vapor deposition, epitaxial silicon growth, and etch, etc.) to manufacture electronic devices. Such processes may produce effluents having undesirable, harmful and/or dangerous chemicals as by-products of the processes. Conventional electronic device manufacturing systems may use abatement apparatus to treat or abate the effluents.
Thus, the gaseous effluents from the manufacturing of electronic devices including semiconductor materials, devices, products and memory articles involve a wide variety of chemical compounds used and produced in the process tools. These compounds include inorganic and organic compounds, breakdown products of photo-resist and other reagents, and a wide variety of other gases that must be removed from the waste gas before being vented from the process facility into the atmosphere.
Electronic device manufacturing processes utilize a variety of chemicals, many of which have extremely low human tolerance levels. Such materials include gaseous hydrides of antimony, arsenic, boron, germanium, nitrogen, phosphorous, silicon, selenium, silane, silane mixtures with phosphine, argon, hydrogen, organosilanes, halosilanes, halogens, organometallics and other organic compounds.
Halogens, e.g., fluorine (F2) and other fluorinated compounds, are particularly problematic among the various components requiring abatement. The electronics industry uses perfluorinated compounds (PFCs) in wafer processing tools to remove residue from deposition steps and to etch thin films. PFCs are recognized to be strong contributors to global warming and the electronics industry is working to reduce the emissions of these gases. The most commonly used PFCs include, but are not limited to, CF4, C2F6, SF6, C3F8, C4H8, C4H8O and NF3. In practice, these PFCs are dissociated in a plasma to generate highly reactive fluoride ions and fluorine radicals, which do the actual cleaning and/or etching. The effluent from these processing operations include mostly fluorine, silicon tetrafluoride (SiF4), hydrogen fluoride (HF), carbonyl fluoride (COF2), CF4 and C2F6.
A significant problem of the semiconductor industry has been the removal of these materials from the effluent gas streams. While virtually all U.S. semiconductor manufacturing facilities utilize scrubbers or similar means for treatment of their effluent gases, the technology employed in these facilities is not capable of removing all toxic or otherwise unacceptable impurities.
One solution to this problem is to incinerate the process gas to oxidize the toxic materials, converting them to less toxic forms. Such systems are almost always over-designed in terms of treatment capacity, and typically do not have the ability to safely deal with a large number of mixed chemistry streams without posing complex reactive chemical risks. Further, conventional incinerators typically achieve less than complete combustion thereby allowing the release of pollutants, such as carbon monoxide (CO) and hydrocarbons (HC), to the atmosphere. Furthermore, one of the problems of great concern in effluent treatment is the formation of acid mist, acid vapors, acid gases and NOx (NO, NO2) prior to discharge.
In addition, conventional incinerators may be expensive to operate due to the consumption of fuel that may be required to satisfactorily combust the effluent. Accordingly, it would be advantageous to provide an improved thermal reactor for the decomposition of highly thermally resistant contaminants in a waste gas that provides high temperatures, through the introduction of highly flammable gases, to ensure substantially complete decomposition of said waste stream while simultaneously reducing the cost of operating such a reactor.
In some aspects, a method of operating an electronic device manufacturing system is provided, including pumping effluent from a processing chamber to a reaction chamber; combusting the effluent in the reaction chamber; driving a turbine with combustion gases from the reaction chamber; generating power from the turbine; and applying the power generated by the turbine to operate the pump.
In other aspects , a system for electronic device manufacturing is provided, including a processing chamber; a pump coupled to the processing chamber and adapted to draw effluent from the processing chamber; a reaction chamber coupled to the pump and adapted to receive the effluent from the pump; and a turbine coupled to the reaction chamber and adapted to be driven by combustion gases from the reaction chamber. The turbine is adapted to generate power which is applied to operate the pump.
In yet other aspects an apparatus for abating effluent from an electronic device manufacturing system is provided, including a pump adapted to couple to a processing chamber and adapted to draw effluent from the processing chamber; a reaction chamber coupled to the pump and adapted to receive the effluent from the pump; and a turbine coupled to the reaction chamber and adapted to be driven by combustion gases from the reaction chamber. The turbine is adapted to generate power which is applied to operate the pump.
Numerous other aspects are provided in accordance with these and other aspects of the invention. Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings.
The manufacturing of electronic devices typically includes numerous processing steps. In any number of these processing steps, different chemicals are used as inputs, and a variety of chemical products are output in effluent streams, many of which may be hazardous. To minimize the release of such hazardous products into the environment, the effluent streams are abated in one or more treatment processes.
Since abatement is an added cost from the point of view of an electronic device manufacturer, attempts are made to minimize the cost of operations (COO) of abatement systems by increasing energy efficiency, improving equipment reliability, reducing material input requirements, decreasing equipment footprint, etc., while adhering to strict safety guidelines and/or regulations (e.g., ESH criteria).
Furthermore, because electronic device manufacturers have differing abatement needs according to the manufacturing processes they employ, abatement systems that are adaptable to such differing needs are more desirable than less flexible systems. More specifically, it may be more desirable to use one type of abatement component, such as a cyclone, within a particular system configuration, while another type of abatement component, such as an electrostatic precipitator, may be preferred in other system configurations. Therefore, an abatement system that can accommodate different modular components on an as-needed basis would be desirable.
The present invention provides apparatus and methods that allow improved performance and reduced cost of operations (COO). In one embodiment, the present invention provides an abatement apparatus having dual reactor chambers that heat effluent streams to a high temperature, with each reactor chamber coupled to a cooling chamber. The cooling chambers feed into a plenum adapted to efficiently transfer energy from the effluent streams exiting the cooling chambers. The apparatus of the present invention is designed to couple to a variety of modular downstream components (‘modular components’) including: blowers, cyclones, mechanical solids trapping systems, co-generators (e.g., low-pressure steam energy recovery device), water scrubbers, cooling towers, acid gas scrubbers, liquid scrubbers, etc.
An abatement system including the inventive apparatus and modular components may include a control system having sensors and one or more processing devices adapted to receive data related to processes in operation, and to control the various components of the abatement apparatus and system, and, in particular, to adapted operation of non-modular components of the abatement system to modular components coupled to the abatement system. For example, the control system may be adapted to reduce humidity in the effluent streams to prevent corrosion, regulate temperature to enable energy recovery at lower temperatures, and otherwise control components to achieve savings in cost of operations.
The present invention further provides a cogeneration abatement system for electronic device manufacturing. In some embodiments, a turbine powered by the combustion of effluent in a reaction chamber is used to generate electricity to power pumps used to move the effluent into the reaction chamber. Combustion of the effluent stream may include burning gases such as, for example, H2, silane, methane, ammonia, flammable PFCs, and/or any combination flammable waste products emitted from an electronic device manufacturing processing chamber. The turbine may be used to generate electricity to power the pumps but may also or alternatively be used for other useful purposes. In some embodiments, in addition to or as an alternative to turbines, other devices such as ceramic turbines, metal turbines, micro turbines, steam turbines, impulse turbines, reaction turbines, and/or combustion furnaces may be used to convert the energy from the combustion of the effluent into a more useful form, e.g., electricity and/or heat.
Turning to
As indicated in
The reaction chamber 106 may be coupled to a power/fuel supply, a reagent supply, and a cooling supply (not shown). The fuel supply, the reagent supply, and the coolant supply, may each be connected to the reaction chamber 106 via conduits which may each include flowmeters. Any suitable flowmeters may be used. Various sensors for monitoring the system 100 may also be coupled to the reaction chamber 106.
The present invention makes use of the combustion gases from the reaction chamber 106 to drive one or more turbines 112 to generate power to drive the pumps 104. In some embodiments, the power generated by the turbines 112 may be used for other purposes. For example, the power from the turbines 104 may be used to pre-heat the effluent stream or to reduce the humidity of the effluent stream. A controller (not shown) may be coupled to one or more of the processing chamber 102, the pumps 104, the reaction chamber 106, the reservoir 108, the scrubber 110, the supplies, the meters, and the sensors.
In operation, the processing chamber 102 may be adapted to perform, and may perform, various processes to manufacture (e.g., fabricate) electronic devices. The processes may be performed in the process chamber 102 at a pressure less than an ambient pressure (e.g., about one atmosphere (atm), etc.). For example, some processes may be performed at pressures of about 8 to about 700 milli-torr (mTorr), although other pressures may be used. To achieve such pressures the pumps 104 may remove effluent (e.g., gas, plasma, etc.) from the process chamber 102.
Chemical precursors (e.g., SiH4, NF3, CF4, BCl3, etc.) of the effluent being removed by the pumps 104 may be added to the process chamber 102 by a variety of means. For example, the chemical precursors may be flowed to the process chamber 102 via a fluid line from a chemical delivery unit.
The effluent may be carried from the process chamber 102 to the reaction chamber 106. More specifically, the pumps 104 may remove the effluent from the process chamber 102 and move the effluent to the reaction chamber 106. The reaction chamber 106 may be adapted to attenuate the undesirable, dangerous or hazardous material in the effluent by combusting the effluent using the fuel supply, reagent supply, and/or cooling supply. The combustion gases may be fed to the turbines 112 which convert the energy in the combustion gases into more easily harnessed energy such as electricity and/or mechanical energy. In some embodiments for example, electricity generated by the turbines 112 may be used to help power the pumps 104.
Turning to
The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above disclosed apparatus and method which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, the turbines may be adapted to mechanically drive the pumps directly.
Accordingly, while the present invention has been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention, as defined by the following claims.
The present application claims priority to U.S. Provisional Patent Application Serial No. 60/931,731, filed May 25, 2007 and entitled “Methods and Apparatus for Abating Effluent Gases Using Modular Treatment Components” (Attorney Docket No. 12073/L), which is hereby incorporated herein by reference in its entirety for all purposes. Also, co-pending, commonly owned U.S. patent application Ser. No. 11/686,005, filed Mar. 14, 2007 and entitled “METHOD AND APPARATUS FOR IMPROVED OPERATION OF AN ABATEMENT SYSTEM” (Attorney Docket No. 9139), is hereby incorporated by reference herein in its entirety and for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 60931731 | May 2007 | US |
