JP2005527369A - Integrated photochemical treatment of gas - Google Patents

Abstract

The present invention relates to an integrated photochemical treatment of gas. According to the present invention, at least one excimer lamp 7 is provided at the outlet of the processing chamber 9, which emits far ultraviolet rays into the gaseous effluent stream 10 for dissociation using photochemical reactions. . In this way, in a small, easily integratable device that does not require dilution, in particular, gases and vapors containing solvents such as isopropyl alcohol, acetone, and N-methylpyrrolidone are carbon dioxide gas or other It is dissociated into the elements.

Description

  The present invention relates to a process in the semiconductor industry for machining and processing semiconductor wafers in process and processing chambers.

  Such processes include, among other things, applying a photoresist layer, developing the photoresist layer, and etching or depositing on a zone of the substrate that is not covered with a mask.

  These various steps are performed in a process and chamber connected to pump means for extracting process steam or gas and residual gas.

  During such a process, the photoresist layer is removed in certain steps, particularly in the stripping chamber.

  In the process of the semiconductor industry, certain process steps, in particular, applying a layer of solvent-based photoresist, developing the photoresist layer, and then removing (ie, stripping) the photoresist layer; And a deposition process (metal organic chemical vapor deposition (MOCVD)) using a metal-organic composition releases effluent containing solvent vapor.

  Such vapors and gases include solvents such as isopropyl alcohol, acetone, and N-methylpyrrolidone, among others.

  These vapors and gases need to be processed before they are pumped by the pump means and discharged to the atmosphere.

  Currently, the treatment of vapor and gas extracted from a stripping chamber or enclosure for metal organic vapor phase epitaxy will then wash the vapor and gas in a wash tower so that the effluent can be treated in liquid form. There is.

  In the washing tower, the flow of effluent is directed upwards with respect to the flow of sprayed diluent that moves downward. This liquid dissolves the vapor and gas for further processing.

  The vertical dimension of the wash tower must be sufficient to allow both liquid droplets and vapors and gases to exist for a time sufficient for dissolution to occur.

  As a result, the gas processing equipment is relatively large and cannot be integrated in close proximity to the stripping enclosure and process chamber, and in particular, is too expensive for clean rooms including process chambers and process chambers. Cannot be incorporated into a double floor.

  Another disadvantage of the known apparatus is that the effluent is diluted before it is processed, so that the processing effect is reduced.

  In application fields other than semiconductors, for example, Japanese Patent Application Laid-Open No. 2000/079322 discloses a solvent in an enclosure for treating gas by means of a biological membrane reaction chamber equipped with means for maintaining wetness of biological membranes following vacuum ultraviolet (VUV). Proposals have already been made to purify the solvent gas by passing the gas. A fan serves to recirculate gas from the reaction chamber outlet to the VUV processing enclosure inlet. The gas is processed at atmospheric pressure. This document does not suggest application to semiconductor manufacturing, and the device appears to be unsuitable for such applications due to the presence of a biomembrane reaction chamber that is too large.

  In the field of processing liquids such as water extracted from the ground, the document DE 297 07 912U teaches spraying water in a purification tower using a countercurrent of air. This air is then processed in an air treatment device with an excimer UV emitter and equipped with a device for cleaning with soda.

  The apparatus described in the above document is complex and large, and is not suitable for solving the problem of integrating close to the stripping enclosure or process chamber.

  Document DE 43 07 204A describes an apparatus for purifying liquids and / or gases in a continuous stream reaction chamber using an excimer laser type UV light source. The fluid flowing through the reaction chamber is exposed to laser light passing through the window. There is no suggestion of application to semiconductor manufacturing or the use of excimer lamps.

  The present invention seeks to avoid the disadvantages of prior art devices in the field of semiconductor manufacturing, in particular by providing a more effective treatment of emissions, with a very significant reduction in emission processing units. Is.

  Therefore, it is desirable to limit the floor area occupied, reduce the risk of equipment contamination, and improve waste disposal.

  In order to achieve these and other objectives, the basic concept of the present invention is the at least partial treatment of vapors and gases upon exiting stripping chambers, metalorganic deposition chambers, and more generally process chambers. The step of decomposing the effluent containing the solvent vapor occurs by exposing the effluent to deep ultraviolet radiation.

  Accordingly, the present invention provides an apparatus for machining or processing a semiconductor wafer, the apparatus comprising a process or process chamber connected by a pipe to pump means for extracting process vapor or gas and residual gas, Alternatively, a plurality of excimer lamps generate deep ultraviolet radiation in the process vapor or gas and residual gas streams in the vicinity of the process or process chamber.

  An excimer lamp can be installed in the steam or gas stream upstream of the pump means. If the pump means comprises a primary pump and a secondary pump, the excimer lamp can be installed in the steam or gas stream upstream of the primary pump and / or upstream of the secondary pump.

  In the first embodiment, the excimer lamp is installed in a specific processing chamber.

  In a second embodiment, excimer lamps are installed in pipes that extract steam and gas from a process or process chamber.

  In a third embodiment, excimer lamps are installed around pipes that extract steam and gases from a process or process chamber.

  An excimer is a composite of excited atoms or molecules that do not have a stable fundamental state in the standard state. A typical example is constituted by an association between two noble gas atoms, for example, XeXe, ArAr, or an association of an electronically excited molecule between a noble gas atom and a halogen atom, for example, XeCl. In either case, the molecule is known as an exciplex (excited state complex) molecule. However, for more generalization, the present invention refers to both excimers and exciplexes using the general term excimer.

  For the intended use of the present invention, the lamp preferably generates radiation having a wavelength in the range of about 100 nm to 200 nm.

  Good results have been obtained with a lamp equipped with at least one XeXe type excimer lamp.

  Advantageously, it may be provided that the excimer lamp is tubular, which itself radiates into its external space carrying the gaseous effluent stream.

  The apparatus preferably further comprises means for injecting oxygen into the vapor or gas stream upstream of the excimer lamp in the form of gaseous oxygen or water vapor.

  The present invention also provides a solvent that exits a semiconductor manufacturing process by a photochemical reaction using irradiation of deep ultraviolet radiation, including a pre-process for treating the vapor or gas as soon as possible after leaving the treatment or process chamber. A method for treating steam-type emissions is provided.

  This irradiation may advantageously be provided by one or more XeXe type excimer lamps.

  It is preferred that in the form of gaseous oxygen or water vapor, oxygen is injected into the vapor or gas for processing upstream of the irradiation of deep ultraviolet radiation.

  By adding oxygen or water vapor, it is possible to provide a better treatment of emissions than normally occurs in semiconductor manufacturing processes. By this addition, it becomes possible to combine with radicals resulting from dissociation by photochemical treatment by oxidation. Other than this, radicals may recombine with each other under certain circumstances, which may result in poor processing. In this regard, provision may be made to add oxygen, water vapor, or some other oxygen containing material.

  Other objects, features and advantages of the present invention will become apparent from the following description of specific embodiments described with reference to the accompanying drawings.

  FIG. 1 is a theoretical view of a cylindrical excimer lamp. A discharge space 1 is formed inside a quartz tube 2 whose outer surface is metal-coated so as to form two electrodes 3 and 4. The electrode 4 has a lattice shape so as to allow the radiation 5 to pass therethrough. Electrodes 3 and 4 are biased by a suitable generator 6.

  In FIG. 2, one or more excimer lamps 7 may be installed in a pipe 8 that extracts steam and gas from a process or process chamber 9, which excimers 5 radiate into a gaseous effluent stream 10. This radiation causes solvent vapors and gases to decompose into carbon dioxide gas and water or other elements.

  The nature of the excimer lamp 7 can be selected depending on the steam and gas being processed. It has been found that XeXe type excimer lamps provide excellent results at a wavelength of about 172 nm for vapors and gases normally produced in the semiconductor industry processes.

  By providing an excimer lamp 7 in the vicinity of the process or process chamber 9 that produces a stream 10 of steam or gas to be processed, the steam and gas are attached to the pipe 8 before being diluted and to extract the steam and gas. Treated before it is time to produce a kimono.

  The shape of the reaction chamber may be adjusted to improve system effectiveness and integration. For example, in FIG. 2, the excimer lamp is a tubular lamp that radiates outward.

  3 and 4, the excimer lamp is a tubular lamp that radiates into the internal space 11 of the tube itself. The discharge space 1 is located between the two concentric quartz tubes 2a and 2b, the electrode 3 is on the outer surface of the outer quartz tube 2a, and the grid electrode 4 is on the inner surface of the inner quartz tube 2b. Thus, the gaseous effluent stream 10 flows directly through the interior space 11 of the excimer lamp 7 and is exposed to radiation 5 that decomposes the effluent into carbon dioxide gas and water or other elements.

  The excimer lamp 7 may be installed in a specific processing chamber, or simply inside or around the pipe 8 for extracting steam and gas.

  Radiation with a wavelength in the range of about 100 nm to about 200 nm is advantageous. This is because a sufficient dissociation rate of steam and gas can be obtained without a catalyst.

The photochemical treatment carried out by the present invention is advantageous in that it avoids the use of particularly expensive, dangerous and / or toxic external reagents such as perfluorocarbon (PFC) and NF ₃ .

  FIG. 5 is a diagram showing a general structure of an apparatus for machining or processing a semiconductor wafer in one embodiment of the present invention. This apparatus comprises a processing chamber or process chamber 9 connected to pump means via a pipe 8. This pump means comprises, for example, a primary pump 13 and a secondary pump 12 connected in series with each other in order to extract process vapors and gases and residual gases from the chamber 9 and to send them through the delivery orifice 14. Is provided. Process steam and gas and residual gas streams flow along the entire vacuum line constituted by the pipe 8 and pumps 12 and 13. In general, a control or shut-off valve 15 is inserted between the process or process chamber 9 and the inlet to the pipe 8.

  This figure shows that the excimer lamp 7 b is located in the steam or gas flow 10 upstream of the primary pump 13.

  This figure also shows that the excimer lamp 7 a is located in the steam or gas flow 10 upstream of the secondary pump 12.

  Surprisingly, the photochemical treatment of the gas is effective not only on the upstream side of the primary pump 13 but also on the upstream side of the secondary pump 12 even under the low-pressure conditions existing in the pipe 8.

  A better treatment effect is obtained by providing means for injecting oxygen into the vapor or gas stream 10 upstream of the excimer lamp in the form of a mixture containing oxygen such as gaseous oxygen or water vapor. For example, FIG. 5 shows an oxygen source 16 that introduces gaseous oxygen through an oxygen injection pipe 17 upstream of the excimer lamp 7b.

  The present invention is not limited to the embodiments explicitly described above, and the present invention includes various generalizations and variations that are within the ability of those skilled in the art.

It is side surface sectional drawing shown by the theoretical figure of a cylindrical excimer lamp. 1 is a schematic side view showing an emission processing system according to an embodiment of the present invention. It is a schematic side view which shows the waste treatment system of the 2nd Embodiment of this invention. It is sectional drawing which cut | disconnected FIG. 3 by the AA surface. 2 is a schematic diagram of an apparatus for machining or processing a semiconductor wafer according to another embodiment of the present invention.

Claims (13)

  An apparatus for machining or processing a semiconductor wafer, comprising a process or process chamber (9) connected by a pipe (8) to pump means (12, 13) for extracting process vapor or gas and residual gas, One or more excimer lamps (7, 7a, 7b) that generate deep ultraviolet radiation are provided in the process steam or gas and residual gas stream (10) in the vicinity of the process or process chamber (9). Features device.   2. The device according to claim 1, characterized in that an excimer lamp (7b) is installed in the steam or gas stream (10) upstream of the primary pump (13).   3. The device according to claim 1, wherein an excimer lamp (7a) is installed in the steam or gas stream (10) upstream of the secondary pump (12).   4. The device according to claim 1, wherein the excimer lamp (7) is installed in a specific processing chamber.   The excimer lamp (7, 7a, 7b) is installed in a pipe (8) for extracting steam and gas from a process or process chamber (9), according to any one of the preceding claims. The device described in 1.   4. Excimer lamp (7) according to any one of the preceding claims, characterized in that an excimer lamp (7) is installed around a pipe (8) for extracting steam and gas from a process or process chamber (9). apparatus.   7. An apparatus according to any one of the preceding claims, characterized in that the excimer lamp (7, 7a, 7b) generates radiation whose wavelength is in the range from about 100 nm to about 200 nm.   8. Device according to any one of the preceding claims, comprising at least one excimer lamp (7) of the XeXe type.   9. A device according to any one of the preceding claims, wherein the excimer lamp (7) is tubular and radiates to its external space carrying the gaseous effluent stream (10).   2. A means for injecting oxygen into the steam or gas stream (10) upstream of the excimer lamp (7, 7a, 7b) in the form of gaseous oxygen or water vapor. The apparatus according to any one of 9.   A method for treating solvent vapor-type effluents exiting a semiconductor manufacturing process, wherein the vapor or gas exits the treatment or process chamber (9) as soon as possible by a photochemical reaction using far-ultraviolet radiation. The processing method characterized by including the pre-process which processes gas.   12. Method according to claim 11, characterized in that the radiation is performed by means of one or more excimer lamps (7) of the XeXe type.   13. A method according to claim 11 or 12, characterized in that oxygen is injected into the vapor or gas in the form of gaseous oxygen or water vapor for treatment upstream of the far ultraviolet radiation.

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