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Microfeature workpiece processing system for, e.g., semiconductor wafer analysisRelated Patent Categories: Etching A Substrate: Processes, Gas Phase Etching Of Substrate, Application Of Energy To The Gaseous Etchant Or To The Substrate Being EtchedMicrofeature workpiece processing system for, e.g., semiconductor wafer analysis description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060191866, Microfeature workpiece processing system for, e.g., semiconductor wafer analysis. Brief Patent Description - Full Patent Description - Patent Application Claims
TECHNICAL FIELD [0001] The present invention is related to equipment and methods for processing microfeature workpieces, e.g., semiconductor wafers. Aspects of the invention have particular utility in connection with removing films, e.g., metallic films, from surfaces of workpieces. BACKGROUND [0002] Surfaces of microfeature workpieces may be subjected to a variety of chemical processes during manufacture or in analytical processes, e.g., in quality control testing. As feature sizes on microfeature workpieces get smaller and performance depends more heavily on control of material compositions, microfeature workpieces become more sensitive to variations or contamination during such chemical processes. [0003] For example, etching may be used in manufacturing operations to selectively remove specific portions of the surface of the workpiece, e.g., to form vias or other functional features, or to pattern a blanket conductive layer. There are generally two types of etching processes--"dry" etching and "wet" etching. Most dry etching operations are carried out using a high-energy plasma that may selectively remove the portions of the microfeature workpiece surface. Wet etching processes are generally conducted in a tank that contains a volume of a chemical etchant liquid. [0004] FIG. 1 schematically illustrates a conventional dry etching system 10. The dry etching system 10 includes a vessel 12 that is designed to receive a microfeature workpiece W. A plasma is delivered to the interior of the vessel 12 by a plasma source 20 and is directed toward the microfeature workpiece W. In the embodiment schematically illustrated in FIG. 1, the plasma source 20 includes a gas supply 22 that communicates with a distributor 24 adjacent the top of the vessel 12. A microwave generator 26 or other energy source is placed in line between the gas supply 22 and the distributor 24 to generate a plasma that is directed toward the microfeature workpiece W by the distributor 24. Waste gas is withdrawn from the vessel 12 by an exhaust 16, which may include a vacuum pump. [0005] In many circumstances, the plasma source 20 will provide sufficient energy to etch the surface of the microfeature workpiece W. In some circumstances, though, it may be advantageous to heat the microfeature workpiece W before, during, or after generating the plasma in the vessel 12. For this reason, dry etch systems may include one or more conduction heaters 14. Such conduction heaters 14 typically are placed outside the vessel 12 to separate them from the plasma and are most commonly positioned below the microfeature workpiece W. This requires that the heat generated by the conduction heater 14 be transferred to the microfeature workpiece W through the wall of the vessel 12. To keep process times acceptably short, the conduction heater 14 must heat this vessel wall significantly above the temperature of the microfeature workpiece W. The high energy plasma and the high temperatures employed by the conduction heaters 14 can significantly limit the materials suitable for forming the vessel 12. [0006] FIG. 2 schematically illustrates a conventional wet etching system 50. In this wet etching system 50, a microfeature workpiece W is positioned in the interior of a tank 52 and immersed in an etching liquid 54. Carrying out wet etching at room temperatures may require the use of an overly aggressive etching liquid that makes it difficult to control the etching of the microfeature workpiece. For this reason, many wet etching systems heat the microfeature workpiece and/or the etching liquid during an etching process. The wet etching system 50 of FIG. 2 is schematically illustrated as having two types of heat sources. The first is an external conduction heater 60 that can conduct heat through the wall of the vessel 52 to heat the microfeature workpiece W, similar to the conduction heater 14 illustrated in FIG. 1. Either in addition to or instead of such an external conduction heater, the wet etching system 50 may include one or more internal heating elements 62. Such internal heating elements 62 can reduce thermal lag in the system and afford greater control over the etching process. Each of these heat sources has its disadvantages, though. As noted above, an external conduction heater 60 requires the wall of the tank 52 to be able to withstand elevated temperatures that exceed the maximum temperature of the etching liquid 54. This can significantly restrict the choice of materials for forming the tank 52. The internal heating elements 62 are in direct contact with the etching liquid. Any contamination from the heating elements 62 in the etching liquid 54 may contaminate the microfeature workpiece W. To limit this contamination, internal heating elements 62 are typically coated with a material that is substantially non-reactive with the etching liquid. Any coating defects that are initially present or that develop over time can still lead to contamination of the etching liquid 54, requiring frequent inspection and maintenance of the internal heating elements 62. In addition, the internal heating elements 62 typically require an electrical or other connection through a wall of the tank 52. Seals may be formed around these connections to limit any leakage or contamination of the etching liquid 54, but such seals are subject to degradation and present another maintenance requirement and potential point of failure. [0007] As noted above, chemical processes may also be used in analyzing aspects of microfeature workpieces. For example, it may be desirable to etch or partially "digest" a microfeature workpiece W as a step in chemically analyzing a microfeature workpiece W. A so-called hot wafer digester, for example, may employ a system similar to the wet etching system 50 to dissolve a layer or film on a surface of the microfeature workpiece W. The resultant contaminated etchant liquid 54 may be analyzed using known analytical chemistry techniques to determine aspects of the composition of the film or other material removed from the microfeature workpiece W. If internal heating elements 62 are employed, though, the potential contamination from these heating elements 62 can reduce the reliability of such chemical analysis and may effectively preclude the detection of ultratrace concentrations of specific components in the material removed from the microfeature workpiece W. If an external conduction heater 60 is used instead of internal heating elements 62, the tank 52 typically must be formed of a high temperature material. One of the most common high temperature materials for hot wafer digesters is quartz. Commercial availability of quartz tanks sufficiently large to handle 300 mm-diameter wafers is quite limited, at least in part due to the difficulty and expense of manufacturing large vessels of high-purity quartz. In addition, hydrofluoric acid, a common semiconductor etchant, generally can not be used in a quartz vessel because it will attack the quartz. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 is a schematic illustration of a conventional dry etching system 10. [0009] FIG. 2 is a schematic illustration of a conventional wet etching system 50. [0010] FIG. 3 is an exploded perspective view schematically illustrating elements of a microfeature workpiece processing system in accordance with one embodiment of the invention. [0011] FIG. 4 is a schematic exploded, cross-sectional view of the elements of the microfeature workpiece processing system shown in FIG. 3. [0012] FIG. 5 is a schematic cross-sectional illustration of a microfeature workpiece processing system employing the elements illustrated in FIGS. 3 and 4. [0013] FIG. 6A is top elevation view of a cover for use in a microfeature workpiece processing system in accordance with a modified embodiment of the invention. [0014] FIG. 6B is a schematic cross-sectional view of the cover of FIG. 6A taken along section line B-B in FIG. 6A. [0015] FIG. 7 is a schematic illustration of a microfeature workpiece processing system in accordance with another embodiment of the invention. DETAILED DESCRIPTION A. Overview [0016] Various embodiments of the present invention provide apparatus and methods for processing microfeature workpieces. Many specific details of the invention are described below with reference to chambers for etching materials, e.g., metal films, from microfeature workpieces. The term "microfeature workpiece" is used throughout to include substrates upon which and/or in which microelectronic devices, micromechanical devices, data storage elements, read/write components, and other devices are fabricated. For example, microfeature workpieces can be semiconductor wafers such as silicon or gallium arsenide wafers, glass substrates, insulative substrates, and many other types of materials. The microfeature workpieces typically have submicron features with dimensions of 0.05 microns or greater. Several embodiments in accordance with the invention are set forth in FIGS. 3-7 and the following text to provide a thorough understanding of particular embodiments of the invention. A person skilled in the art will understand, however, that the invention may have additional embodiments, or that the invention may be practiced without several of the details of the embodiments shown in FIGS. 3-7. [0017] One embodiment of the invention provides a method of processing a microfeature workpiece. In accordance with this method, a microfeature workpiece is supported by a support, which may be unheated, in an interior of a processing chamber. A surface of the microfeature workpiece is contacted with an etchant liquid; a wall of the processing chamber is substantially non-reactive with the etchant liquid. The etchant liquid may be heated by delivering radiation from a radiation source through the wall of the processing chamber to heat the etchant liquid. The wall is highly transmissive of an operative wavelength range of the radiation and the etchant liquid is absorptive of the operative wavelength range. If so desired, the radiation source may be controlled to maintain a temperature of the etchant liquid at or above a target process temperature to etch the surface of the microfeature workpiece. The etched microfeature workpiece may be removed from the processing chamber. [0018] A method of processing a microfeature workpiece in accordance with another embodiment of the invention involves positioning a microfeature workpiece on a support, which may be unheated, in an interior of a processing chamber, which may have an inner surface comprising a polymer. The microfeature workpiece may be enclosed within the interior of the processing chamber and a surface of the microfeature workpiece may be contacted with an etchant liquid at a first temperature. The etchant liquid may be substantially non-reactive with the inner surface of the processing chamber. This method continues by heating the etchant liquid from the first temperature to a second temperature using an infrared heat source positioned entirely outside the enclosed processing chamber. The second temperature is higher than the first temperature and the second temperature promotes etching of a surface of the microfeature workpiece. The surface of the microfeature workpiece may be etched with the etchant's liquid at or above the second temperature. [0019] Another embodiment of the invention provides a method of processing a microfeature workpiece. In accordance with this embodiment, a microfeature workpiece supported in an interior of a processing chamber is contacted with a processing fluid. Infrared radiation is delivered through the wall of the processing chamber to heat the processing fluid from a first temperature to a higher second temperature that promotes processing of the microfeature workpiece surface. A temperature of the processing fluid may be maintained at or above the second temperature for a process time to process the surface of the microfeature workpiece. A temperature of the processing chamber wall may be no greater than the temperature of the processing fluid during the processing. Continue reading about Microfeature workpiece processing system for, e.g., semiconductor wafer analysis... Full patent description for Microfeature workpiece processing system for, e.g., semiconductor wafer analysis Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Microfeature workpiece processing system for, e.g., semiconductor wafer analysis patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Microfeature workpiece processing system for, e.g., semiconductor wafer analysis or other areas of interest. ### Previous Patent Application: Method of processing substrate, method of manufacturing solid-state imaging device, method of manufacturing thin film device, and programs for implementing the methods Next Patent Application: Method of processing organic film and method of manufacturing semiconductor device Industry Class: Etching a substrate: processes ### FreshPatents.com Support Thank you for viewing the Microfeature workpiece processing system for, e.g., semiconductor wafer analysis patent info. IP-related news and info Results in 0.13308 seconds Other interesting Feshpatents.com categories: Canon USA , Celera Genomics , Cephalon, Inc. , Cingular Wireless , Clorox , Colgate-Palmolive , Corning , Cymer , 174 |
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