JP2019014624A - Electric discharge reaction apparatus - Google Patents

Abstract

To provide an electric discharge reaction apparatus that can improve energy efficiency for an electric discharge reaction.SOLUTION: An electric discharge reaction apparatus 1 has a first electrode member 3 and a second electrode member 2 facing each other, a first dielectric 5 provided on the surface of the first electrode member 3, a gas supply part 6 that supplies raw material gas G to between the first electrode member 3 and the second electrode member 2, and a power supply part 7 that is connected to the first electrode member 3 and the second electrode member 2 and applies voltage for generating electric discharge between the first electrode member 3 and the second electrode member 2. On the surface of the second electrode member 2, formed is a trench groove 8. A trough part 9 of the trench groove 8 is filled with the second dielectric 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a discharge reaction apparatus that generates a reaction gas from a raw material gas by generating a discharge between electrodes, and more particularly to a technique for increasing energy efficiency for generating ozone.

  Conventionally, an ozone generator that generates ozone gas (reactive gas) from oxygen gas (raw material gas) by generating discharge between electrodes has been proposed. In a conventional ozone generator, oxygen gas is supplied between a pair of electrodes having electrode surfaces facing each other, and a high voltage is applied from a high-voltage AC power source to generate a discharge to generate ozone gas (for example, a patent) Reference 1). The ozone gas generated in this way is used for manufacturing processes such as semiconductors and liquid crystal panels.

  Conventionally, a technique for generating ozone with high efficiency by forming a groove on the surface of an electrode has been proposed (see, for example, Patent Document 2). Thus, when a groove is formed on the surface of the electrode, the electric field strength is high at the peak (top) of the groove of the electrode, a stronger discharge is performed, and high-concentration ozone can be generated.

JP 2002-20105 A JP-A-63-137748

  However, in the conventional technique, although discharge is performed at the peak (top) of the groove of the electrode, discharge is also performed at the valley of the groove of the electrode. The discharge at the valley of this groove has a low energy density and does not contribute much to the generation of ozone. Depending on the conditions of use, it may affect the decomposition of ozone, and the energy efficiency for ozone generation (discharge reaction) is sufficient. There was a problem that it could not be raised.

  This invention is made | formed in view of said subject, and it aims at providing the discharge reaction apparatus which can improve the energy efficiency for discharge reaction.

  The discharge reaction apparatus of the present invention includes a first electrode member and a second electrode member facing each other, a first dielectric provided on a surface of the first electrode member, the first electrode member, A gas supply unit that supplies a source gas between the second electrode members, and is connected to the first electrode member and the second electrode member, and between the first electrode member and the second electrode member And a power source for applying a voltage for generating a discharge at the surface, and a trench groove is formed on a surface of the second electrode member, and a trough of the trench groove is formed by a second dielectric. It is filled with.

  According to this configuration, since the trough of the trench groove of the electrode member (second electrode member) is filled with the dielectric (second dielectric), the discharge at the trough (does not contribute much to the discharge reaction). Discharge) can be suppressed, and the energy efficiency for the discharge reaction can be increased.

  Moreover, in the discharge reaction apparatus of the present invention, the peak portion of the trench groove has a projecting top portion, and the top portion is from the surface of the second dielectric filling the valley portion. It may protrude.

  According to this configuration, it is possible to generate a discharge with a high electric field strength at the peak (top) of the trench groove. Furthermore, since the discharge characteristics of the peak (top) of the trench groove are not significantly different from those of the conventional discharge reaction device (discharge reaction device in which the trough of the trench groove of the electrode member is not filled with a dielectric), Characteristic data can be used effectively.

  In the discharge reaction device of the present invention, the height at which the top protrudes from the surface of the second dielectric may be 0 to 0.25 mm.

  Further, in the discharge reaction device of the present invention, the peak portion of the trench groove has a planar top portion, and the top portion is a surface of the second dielectric that fills the valley portion. It may be exposed in the same plane.

  According to this configuration, since the peak portion (top portion) of the trench groove is flush with the surface of the dielectric filling the valley portion, the trench groove can be manufactured with high accuracy by, for example, machining.

  In the discharge reaction apparatus of the present invention, the exposed width of the top may be 0 to 0.5 mm.

  In the discharge reaction apparatus of the present invention, titanium, tungsten, antimony, manganese, iron, cobalt, nickel, vanadium, zinc, tantalum, niobium, yttrium, or zirconium is incorporated in the second dielectric. Also good.

  According to this configuration, a metal such as titanium, tungsten, antimony, manganese, iron, cobalt, nickel, vanadium, zinc, tantalum, niobium, yttrium, or zirconium is taken into the dielectric (second dielectric). Therefore, even if nitrogen gas is not added, a high-purity source gas (for example, pure oxygen gas having a purity of 99.99% or more) is used to stabilize a high-concentration reaction gas (for example, ozone gas). Can be generated for a long time. Therefore, it is possible to generate a clean reaction gas (for example, ozone gas) that does not contain NOx.

  According to the present invention, the energy efficiency for the discharge reaction can be increased.

It is explanatory drawing which shows roughly the main structures of the discharge reaction apparatus in embodiment of this invention. It is a top view which shows the circular electrode surface of the discharge reaction apparatus in embodiment of this invention. It is a figure which shows an example of the electrode shape of the discharge reaction apparatus in embodiment of this invention. It is a figure which shows an example of the electrode shape of the discharge reaction apparatus in embodiment of this invention. It is a figure which shows an example of the electrode shape of the discharge reaction apparatus in embodiment of this invention.

  Hereinafter, a discharge reaction apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a case of a discharge reaction apparatus used in a manufacturing process of a semiconductor, a liquid crystal panel or the like is illustrated.

  The configuration of the discharge reaction apparatus according to the embodiment of the present invention will be described with reference to the drawings. Here, first, the principle of the discharge reaction apparatus of the present embodiment will be described. FIG. 1 is an explanatory diagram showing the main configuration of the discharge reaction apparatus of the present embodiment. As shown in FIG. 1, a discharge reaction apparatus 1 includes a pair of electrode members (high voltage electrode 2 and ground electrode 3) facing each other, a dielectric 4 provided on the surface of the electrode member 2 (high voltage electrode 2), an electrode A dielectric 5 provided on the surface of the member 3 (ground electrode 3), a gas supply unit 6 for supplying a source gas G (for example, oxygen gas) between the pair of electrode members 2 and 3, a pair of electrode members 2, 3 is provided.

  The power supply unit 7 has a function of applying a voltage for generating a discharge between the pair of electrode members 2 and 3. In this case, the high voltage side of the power supply unit 7 is connected to the high voltage electrode 2, and a high voltage is applied to the high voltage electrode 2. The ground electrode 3 is grounded. A plurality of trench grooves 8 are provided on the surface of the high voltage electrode 2. The valley portion 9 of the trench groove 8 is filled with the dielectric 4.

  The dielectric 4 is formed by thermal spraying or an inorganic adhesive. For example, when the dielectric 4 is formed by thermal spraying, titanium (Ti), tungsten (W), antimony (Sb), manganese (Mn), iron (Fe), cobalt ( Co), nickel (Ni), vanadium (V), zinc (Zn), tantalum (Ta), niobium (Nb), yttrium (Y), or zirconium (Zr) powder, It is preferable to apply by plasma spraying that can form a film at a low temperature. Moreover, it is preferable to make the bulge by thermal spraying flat by machining.

  When the dielectric 4 is formed with an inorganic adhesive, titanium (Ti), tungsten (W), antimony (Sb), manganese (Mn) is used as a paste-like material mainly composed of alumina, silica, or the like. ), Iron (Fe), cobalt (Co), nickel (Ni), vanadium (V), zinc (Zn), tantalum (Ta), niobium (Nb), yttrium (Y), or zirconium (Zr) powder It is preferable to form by mixing, filling the groove, and firing.

Note that vanadium, antimony, tungsten, manganese, iron, nickel, cobalt, or titanium is an oxide (for example, V ₂ O ₅ , Sb ₂ O ₃ , WO ₃ , Mn ₃ O ₄ , Fe ₂ O ₃ , NiO). , Co ₃ O ₄ , CaTiO ₃ , MgTiO ₃ , TiO _3, etc.) may be incorporated into the sprayed film or the inorganic adhesive. Alternatively, tungsten, titanium, or tantalum is an alloy (for example, WC (tungsten carbide), TiC (titanium carbide), TaC (tantalum carbide), TiN (titanium nitride), TiCN (titanium carbonitride), etc.) It may be incorporated into a sprayed film or an inorganic adhesive.

  Next, a specific example of the discharge reaction device 1 of the present embodiment will be described. FIG. 2 is a diagram illustrating an example of the high-voltage electrode 2. As shown in FIG. 2, a circular electrode surface is used as the high voltage electrode 2.

  In general, the discharge reaction device 1 (ozone generator) is a dielectric that is disposed between a pair of electrode members (a high-voltage electrode 2 and a ground electrode 3) having circular electrode surfaces facing each other and the electrode members 2 and 3 facing each other. It has a body 5 and a disk-shaped space. The disk-shaped space is a space between the opposing circular electrode surfaces (a space in which discharge occurs), and oxygen is converted into ozone when a source gas containing oxygen flows into this space. The high voltage electrode 2 is connected to the high voltage side of the power source, and the ground electrode 3 is connected to the ground side of the power source. In the present embodiment, the plurality of trench grooves 8 are formed on the surface of the high-voltage electrode 2, but a plurality of trench grooves may be formed on the surface of the ground electrode 3. That is, the electrode forming the trench groove may be a high voltage electrode or a ground electrode.

  FIG. 3 is a diagram showing an example of the electrode shape of the discharge reaction apparatus 1 of the present embodiment. As shown in FIG. 3, the electrode surface of the high-voltage electrode 2 includes a plurality of trench grooves 8. In this case, the trench grooves 8 are arranged concentrically and extend substantially parallel to each other. As described above, the dielectric 4 is formed in the valley portion 9 of the trench groove 8 by thermal spraying or an inorganic adhesive.

  As shown in FIG. 3, the peak portion 10 of the trench groove 8 has a protruding top portion 11, and the top portion 11 protrudes from the surface of the dielectric 4 filling the valley portion 9. Yes. For example, the height A at which the top 11 protrudes from the surface of the dielectric 4 is 0 to 0.25 mm. The depth (the height from the valley portion 9 to the top portion 11) B of the trench groove 8 is 0.3 to 1.5 mm, and the pitch C of the top portion 11 is 0.75 to 3.0 mm.

  The high voltage electrode 2 is made of metal. The ground electrode 3 is formed of a silver-based metallized layer provided on the back surface of sapphire, and the dielectric 5 is formed of disc-shaped single crystal sapphire. The discharge space is formed by a space between the peak portion 10 of the trench groove 8 and the surface of the dielectric 4 and the dielectric 5 (see FIG. 1). The distance between the peak portion 10 of the trench groove 8 and the dielectric 5 is 0.01 mm to 0.3 mm. When clean ozone gas used for semiconductor manufacture is required, the material of the dielectric 5 is suitably a clean material such as sapphire, high-purity alumina ceramics, high-purity quartz glass, or the like.

  As shown in FIG. 2, the raw material gas G is introduced into the disk-shaped space through the inlet passage 12 and the outer peripheral space 13, and flows in the disk-shaped space almost inward in the radial direction. Are gathered into a central space 14 provided in the center, and are guided radially outward of the electrode through a guide passage 15. In this case, the source gas G flows in a direction across the trench groove 8 in the space between the trench groove 8 and the dielectric 5. The source gas G may flow radially outward instead of flowing substantially radially inward in the disk-shaped space. In this case, the source gas is first supplied to the central space 14 through the guide passage 15, flows in the disk-shaped space substantially outward in the radial direction, and is guided to the inlet passage 12 through the outer peripheral space 13.

  The high voltage electrode 2 is connected to the high voltage side of the power supply unit 7, and the ground electrode 3 is connected to the ground side of the power supply unit 7. Then, a high-voltage AC voltage is applied to the disk-shaped space between both electrodes 2 and 3, and a barrier discharge is generated in the disk-shaped space between both electrodes 2 and 3. A raw material gas G containing oxygen flows through the disk-shaped space, and a part thereof is converted into ozone. In the present embodiment, the flow of the source gas G is set in a direction crossing a large number of trench grooves 8, and always passes through the top 11 of the trench grooves 8 having a high discharge density, so that high-concentration ozone can be generated. It is.

  In the discharge reaction device 1 of the present embodiment, the raw material gas G is supplied between the pair of electrode members 2 and 3, and a voltage is applied from the power supply unit 7 to generate discharge. In this case, portions of the pair of electrode members 2 and 3 that are in contact with the discharge (surface of the ground electrode 2) are made of aluminum as an electrode material and are covered with an anodized film. By covering the electrode with the anodized film, the durability of the electrode is improved.

  Further, in the present embodiment, the dielectric 4 is formed in the valley portion 9 of the trench groove 8 by thermal spraying or an inorganic adhesive. Since the dielectric 4 contains a metal such as titanium, tungsten, antimony, manganese, iron, cobalt, nickel, vanadium, zinc, tantalum, niobium, yttrium, or zirconium, nitrogen gas is not added. In addition, a high-concentration reaction gas (for example, ozone gas) can be stably generated for a long time using a high-purity source gas (for example, pure oxygen gas having a purity of 99.99% or more). Therefore, it is possible to generate a clean reaction gas (for example, ozone gas) that does not contain NOx.

  Here, conventionally, a phenomenon in which the ozone concentration is gradually reduced unless nitrogen gas is added will be described. Under plasma due to electric discharge, a phenomenon occurs in which atoms constituting the electrode surface escape from the electrode surface. Then, in the vicinity of the region where the phenomenon occurs, an area occupied by electrons (unpaired electrons) that do not participate in the binding appears due to loss of the covalent bond partner. Since the unpaired electron is unstable, it becomes chemically active, and the unpaired electron and ozone are combined. The combined ozone is decomposed back to oxygen gas. Since the area occupied by such unpaired electrons gradually increases with the discharge time, it is considered that the concentration of ozone gas gradually decreases accordingly.

  Next, the principle that the ozone concentration can be maintained by adding nitrogen gas will be described. When nitrogen gas is added, NOx generated by plasma due to discharge is taken into the area of unpaired electrons, and the active point is considered to be blocked. Therefore, conventionally, a high concentration of ozone gas can be stably generated by adding a small amount of nitrogen gas. In the present embodiment, a high-concentration reaction gas (for example, a pure oxygen gas having a purity of 99.99% or more) is used by using a high-purity source gas (for example, pure oxygen gas having a purity of 99.99% or more) without adding nitrogen gas as in the prior art. , Ozone gas, etc.) can be generated stably for a long time. The reason is that by incorporating the metal into the dielectric 4 of the trench groove 8, the metal molecules or atoms or ions are combined with the area occupied by unpaired electrons, and the active site is blocked. It is thought that it is because there is.

  An oxide such as vanadium, antimony, tungsten, manganese, iron, nickel, cobalt, or titanium may be taken into the dielectric 4 of the trench groove 8. Also in this case, similarly to the above, a high-concentration reaction gas (for example, a pure oxygen gas having a purity of 99.99% or more) is used without adding nitrogen gas. , Ozone gas, etc.) can be generated stably for a long time.

  Alternatively, an alloy such as tungsten, titanium, or tantalum may be taken into the dielectric 4 of the trench groove 8. Also in this case, similarly to the above, a high-concentration reaction gas (for example, a pure oxygen gas having a purity of 99.99% or more) is used without adding nitrogen gas. , Ozone gas, etc.) can be generated stably for a long time.

  As described above, according to the discharge reaction device 1 of the present embodiment, since the valley portion 9 of the trench groove 8 of the electrode member 2 is filled with the dielectric 4, the discharge (ozone generation in the valley portion 9) is performed. Discharge that does not contribute much to the energy), and energy efficiency for ozone generation can be increased.

  Further, in the present embodiment, a discharge with a high electric field strength can be generated in the peak portion 10 (top portion 11) of the trench groove 8. Furthermore, the discharge characteristics of the peak portion 10 (top portion 11) of the trench groove 8 are not significantly different from those of the conventional discharge reaction device (discharge reaction device in which the valley portion of the trench groove of the electrode member is not filled with a dielectric). Therefore, the conventional characteristic data can be used effectively.

  In the present embodiment, the dielectric 4 is incorporated with a metal such as titanium, tungsten, antimony, manganese, iron, cobalt, nickel, vanadium, zinc, tantalum, niobium, yttrium, or zirconium. Even if nitrogen gas is not added, a high-purity source gas (for example, pure oxygen gas having a purity of 99.99% or more) is used to stably supply a high-concentration reaction gas (for example, ozone gas) for a long time. Can be generated. Therefore, it is possible to generate a clean reaction gas (for example, ozone gas) that does not contain NOx.

  The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

  For example, FIG. 4 shows another example of the electrode shape of the discharge reaction device 1. As shown in FIG. 4, the peak portion 10 of the trench groove 8 has a planar top 21, and the top 21 is exposed in the same plane as the surface of the dielectric 4 filling the valley 9. You may do it. For example, the exposed width D of the top 21 is 0 to 0.5 mm. Thus, if the crest 10 (top 21) of the trench 8 is flush with the surface of the dielectric 4 filling the trough 9, it can be manufactured with high precision by machining.

  FIG. 5 shows still another example of the electrode shape of the discharge reaction apparatus 1. As shown in FIG. 5, the peak portion 10 (the top portion 11) of the trench groove 8 may be filled with the dielectric 4. For example, the buried width E of the top 11 (top 11) is 0 to 0.5 mm. Thus, if the peak part 10 (top part 11) of the trench groove | channel 8 is filled with the dielectric material 4, since the electrode member 2 is not exposed to discharge, durability of an electrode member can be improved.

  As described above, the discharge reaction apparatus according to the present invention has an effect that the energy efficiency for the discharge reaction can be increased, and is useful for use in manufacturing processes of semiconductors and liquid crystal panels.

1 Discharge reactor (ozone generator)
2 Second electrode member (high voltage electrode)
3 First electrode member (ground electrode)
4 Second dielectric 5 First dielectric 6 Gas supply part 7 Power supply part 8 Trench groove 9 Valley part 10 Mountain part 11 Top part (projection shape)
12 Entrance passage 13 Outer peripheral space 14 Central space 15 Guide passage 21 Top (planar shape)

Claims (6)

A first electrode member and a second electrode member facing each other;
A first dielectric provided on a surface of the first electrode member;
A gas supply unit for supplying a source gas between the first electrode member and the second electrode member;
A power supply unit that is connected to the first electrode member and the second electrode member and applies a voltage for generating a discharge between the first electrode member and the second electrode member;
With
A trench groove is formed on the surface of the second electrode member,
The discharge reactor according to claim 1, wherein a trough of the trench is filled with a second dielectric. The peak of the trench groove has a protruding top.
The discharge reaction apparatus according to claim 1, wherein the top portion protrudes from a surface of the second dielectric material filling the valley portion.   The discharge reaction apparatus according to claim 2, wherein a height at which the top projects from the surface of the second dielectric is 0 to 0.25 mm. The peak portion of the trench groove has a planar top.
The discharge reaction apparatus according to claim 1, wherein the top is exposed in the same plane as a surface of the second dielectric filling the valley.   The discharge reactor according to claim 4, wherein the exposed width of the top is 0 to 0.5 mm.   The titanium oxide, tungsten, antimony, manganese, iron, cobalt, nickel, vanadium, zinc, tantalum, niobium, yttrium, or zirconium is incorporated in the second dielectric material. The discharge reaction apparatus according to one item.

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