JP2007185635A - Device for discharging treating gas and surface treatment apparatus with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for discharging treating gas in which the concentration of a line of electric force is moderated to restrain the convergence of an electric discharge. <P>SOLUTION: The device 20 for discharging the treating gas is provided with: a tubular external dielectric 22 having a supply hole 23 in the upper part of the outer circumferential surface thereof and a discharge hole 24 in the lower part of the outer circumferential surface thereof; an external electrode which is arranged on the outer circumferential surface of the external dielectric 22 and grounded; a tubular internal dielectric 35 arranged in a tube of the external dielectric 22 and coaxially therewith while leaving a constant space between them; an internal electrode 37 arranged in a tube of the internal dielectric 35; a high-frequency power source 39 for applying high-frequency voltage between the internal electrode 37 and the external electrode; trumpet-shaped electrically conductive members 29 which are arranged at both ends of the external electrode in the axial direction of the external dielectric 22 and coaxially with the external dielectric 22, is connected to the external electrode and surrounds the external dielectric 22 while leaving a space between them; and a gas supplying mechanism 50 for supplying the treating gas from the supply hole 23 to the space between the external dielectric 22 and the internal dielectric 35. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a processing gas discharge device that converts a processing gas into plasma and discharges it, and a surface processing device that includes the processing gas discharge device and processes the surface of a processing object with the processing gas discharged from the processing gas discharge device. .

  Conventionally, as the surface treatment apparatus, for example, one disclosed in Japanese Patent Application Laid-Open No. 2001-35835 is known, and this surface treatment apparatus is disposed above a sheet-like treatment object that is appropriately supported. And a processing gas discharge device including a discharge mechanism that discharges the processing gas into plasma toward the processing object and a gas supply mechanism that supplies the processing gas to the discharge mechanism.

  The discharge mechanism is formed in a tubular shape, and is provided with an external dielectric disposed above the object to be processed, an external electrode provided on the outer peripheral surface of the external dielectric and grounded, and formed in a tubular shape. An internal electrode provided in the tube so as to be spaced apart from the external dielectric and coaxially with the external dielectric, a high-frequency power source for applying a high-frequency voltage between the internal electrode and the external electrode, and the internal electrode A coolant circulation mechanism for circulating and circulating the coolant inside the pipe is provided.

  The external dielectric includes a supply hole that opens to the upper outer peripheral surface and supplies a processing gas, and a discharge hole that opens to the lower outer peripheral surface and discharges the supplied processing gas toward a processing object. The supply hole and the discharge hole are each formed in a slit shape whose longitudinal direction is parallel to the axis of the external dielectric.

  The gas supply mechanism includes a gas introduction portion connected to a supply hole of the external dielectric, and supplies a processing gas from the supply hole to the external dielectric and the internal electrode via the gas introduction portion.

  According to this surface treatment apparatus, the process gas is supplied between the external dielectric and the internal electrode from the supply hole through the gas introduction portion by the gas supply mechanism, and between the internal electrode and the external electrode by the high frequency power source. A high frequency voltage is applied to the first electrode, and a high frequency electric field is formed by the internal electrode and the external electrode.

  The processing gas supplied between the external dielectric and the internal electrode flows between the external dielectric and the internal electrode toward the discharge hole side, and the internal and external electrodes (external dielectric) by the high-frequency electric field. Is generated into the plasma containing radical atoms and ions, and is discharged from the discharge hole toward the processing object below the discharge hole. Then, the processing object is processed by the plasma-ized processing gas discharged in this manner.

JP 2001-35835 A

  By the way, in the above-described conventional surface treatment apparatus, the electric lines of force R are concentrated at both ends of the external electrode 101 in the axial direction of the external dielectric 102 as shown in FIG. ing. For this reason, in the conventional surface treatment apparatus, discharge is concentrated between the end portion and the internal electrode 103, and the external dielectric 102 near the end portion is locally increased in temperature and damaged. It was causing the problem.

  The present invention has been made in view of the above circumstances, and is a processing gas discharge device capable of reducing the concentration of electric lines of force and suppressing the concentration of discharge, and a surface treatment including the processing gas discharge device. The purpose is to provide a device.

To achieve the above object, the present invention provides:
A processing gas discharge device comprising discharge means for converting a processing gas into plasma and discharging, and gas supply means for supplying the processing gas to the discharge means;
The discharge means is
An external dielectric made of a tubular member and having a supply hole to which the processing gas is supplied and a discharge hole for discharging the supplied processing gas opened on an outer peripheral surface;
An outer electrode provided on the outer peripheral surface of the external dielectric at a position that does not block the supply hole and the discharge hole, and is grounded;
An inner dielectric formed of a tubular member and provided in the outer dielectric tube so as to be spaced apart from the inner peripheral surface of the outer dielectric and coaxially with the outer dielectric;
An internal electrode provided in the internal dielectric tube;
Voltage application means for applying a voltage between the internal electrode and the external electrode,
The gas supply means is configured to supply the processing gas between the external dielectric and the internal dielectric from the supply hole,
The processing gas supplied between the external dielectric and the internal dielectric is turned into plasma by applying a voltage between the internal electrode and the external electrode by the voltage applying means, and then the discharge hole. In the processing gas discharge device configured to be discharged from the outside,
Conductive members disposed at both ends of the external electrode in the axial direction of the external dielectric and connected to the external electrodes, respectively, and the conductive member is connected to the external electrode in a circumferential direction of the external dielectric. The outer dielectric is formed in an arc shape at a distance from the outer peripheral surface of the external dielectric, and the inner diameter increases as the distance from the both ends of the external electrode in the axial direction of the external dielectric increases. Further, the present invention relates to a processing gas discharge device which is formed to be inclined with respect to the axis of the external dielectric.

  According to the processing gas discharge device, when the processing gas is supplied from the supply hole between the external dielectric and the internal dielectric by the gas supply means, the supplied processing gas is supplied to the external dielectric and the internal dielectric. Flows toward the discharge hole.

  A voltage is applied between the internal electrode and the external electrode by a voltage applying means, and an electric field is formed by the internal electrode and the external electrode, and the processing gas is separated from the internal electrode (internal dielectric) by the electric field. ) And an external electrode (external dielectric) to generate plasma containing radical atoms and ions. The plasma-ized processing gas is discharged from the discharge hole toward the outside.

  In the present invention, the external electrode is provided in an arc shape at both ends of the external electrode in the axial direction with a space from the outer peripheral surface of the external dielectric, and the external diameter is increased so as to increase from the both ends of the external electrode. A conductive member inclined with respect to the axis of the dielectric is provided connected to the external electrode, and by providing such a conductive member that gradually moves away from the outer peripheral surface of the external dielectric, the lines of electric force are generated on the conductive member side. It is possible to alleviate the concentration of electric lines of force at both ends of the external electrode, and the lines of electric force are concentrated at both ends of the external electrode as in the conventional surface treatment apparatus. It is possible to prevent a nearby electric field from becoming strong.

  As a result, the concentration of discharge at both ends of the external electrode is suppressed, and the local temperature increase of the external dielectric and the internal dielectric near the both ends due to the concentration of discharge is prevented. And damage to the internal dielectric can be prevented.

  The inclination angle of the conductive member with respect to the axis of the external dielectric is preferably 2 ° to 30 °. This is because when the tilt angle is smaller than 2 °, the electric lines of force concentrate at the end on the upper side in the tilt direction of the conductive member, and the discharge concentrates at the end, and when the tilt angle is larger than 30 °, This is because the lines of electric force concentrate on the lower end of the member in the tilt direction and the discharge concentrates on the end, so that local temperature rise of the external dielectric and the internal dielectric cannot be prevented. Therefore, if it is within the above-mentioned angle range, it is possible to effectively alleviate the concentration of electric lines of force and suppress the concentration of discharge, and to prevent local temperature rise of the external dielectric and the internal dielectric.

The present invention also provides:
Support means for supporting the object to be treated;
Including the processing gas discharge device described above,
The processing gas discharge device is disposed so that the discharge hole faces the processing object supported by the support means,
According to the surface treatment apparatus, the surface of the object to be treated is treated with the treatment gas discharged from the treatment gas discharge apparatus.

  According to this surface treatment apparatus, since the process gas discharge device can prevent the external dielectric and the internal dielectric from being damaged as described above, the plasma surface treatment (e.g., the number of maintenance can be reduced) Surface modification treatment, cleaning treatment, film formation treatment, etc.) can be carried out efficiently.

  As described above, according to the processing gas discharge apparatus according to the present invention, it is possible to prevent the local temperature rise of the external dielectric and the internal dielectric due to the concentration of discharge and prevent them from being damaged, In addition, according to the surface treatment apparatus of the present invention, plasma surface treatment can be efficiently performed, for example, the number of maintenance can be reduced.

  Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a front sectional view showing a schematic configuration of a surface treatment apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view in the direction of arrows AA in FIG. These are sectional drawings of the arrow BB direction in FIG. 4 is a plan view showing the schematic configuration of the external dielectric according to the present embodiment, FIG. 5 is a bottom view of the external dielectric shown in FIG. 4, and FIG. 6 is the present embodiment. FIG. 7 is a cross-sectional view illustrating a schematic configuration of the internal electrode and the cooling pipe according to the present embodiment, and FIG. 8 illustrates the schematic configuration of the internal electrode according to the present embodiment. It is the bottom view which showed schematic structure of the connection member and the baffle plate.

  As shown in FIGS. 1 to 3, the surface treatment apparatus 1 of the present example horizontally supports a substrate K as a processing object and conveys the substrate K in a predetermined direction (the direction indicated by the arrows in FIGS. 2 and 3). 10 and a discharge mechanism 21 that is disposed above the substrate K that is transported by the transport roller 10 and that discharges the processing gas into plasma toward the substrate K, and a gas that supplies the processing gas to the discharge mechanism 21 A processing gas discharge device 20 including a supply mechanism 50 is provided.

  A plurality of the transport rollers 10 are arranged at predetermined intervals along the substrate transport direction, and both end portions of the rotation shaft 10a are rotatably supported by support members (not shown). Further, the conveyance roller 10 has one end of a rotary shaft 10a connected to a drive mechanism (not shown), and the drive shaft (not shown) causes the rotary shaft 10a to rotate about the axis, The substrate K is transported in the substrate transport direction.

  The discharge mechanism 21 includes an external dielectric 22 made of a quartz glass tube, an external electrode 26 provided on the outer peripheral surface of the external dielectric 22, and a metal such as aluminum. A holding member 27 for holding 22, a metal such as stainless steel, a trumpet-shaped conductive member 29 provided at both ends of the holding member 27 in the axial direction of the external dielectric 22, a quartz glass tube, and the like, In the tube of the external dielectric 22, an internal dielectric 35 is provided so as to be spaced apart from the inner peripheral surface of the external dielectric 22 and coaxially with the external dielectric 22, and provided in the tube of the internal dielectric 35. The coolant is circulated and circulated through the internal electrode 36, the high-frequency power source 39 that applies a high-frequency voltage between the internal electrode 36 and the external electrode 26, and the internal electrode 36 and the holding member 27. That includes a coolant circulation system 40.

  The external dielectric 22 is provided above the substrate K so that its axis is orthogonal to the substrate transport direction and faces the substrate K at a predetermined interval over the entire width of the substrate K. A convex portion 22a formed on the surface, a flange portion 22b formed on both ends, a supply hole 23 penetrating from the upper surface of the convex portion 22a to the inner peripheral surface and supplied with a processing gas from the gas supply mechanism 50, A discharge hole 24 that penetrates from the lower outer peripheral surface to the inner peripheral surface and discharges the supplied processing gas toward the substrate K is provided.

  The supply hole 23 and the discharge hole 24 are each composed of a plurality of slit holes formed in a line in the axial direction of the external dielectric 22, as shown in FIGS. Slit portions 23a and 24a having predetermined lengths L1 and L4, and round holes 23b formed at both ends of the slit portions 23a and 24a and having diameters D1 and D2 larger than the slit widths L2 and L5 of the slit portions 23a and 24a, 24b (the diameter D1 is larger than the slit width L2 and the diameter D2 is larger than the slit width L5), and the distance between adjacent ends is predetermined so that the longitudinal direction is along the axis of the external dielectric 22 They are formed so as to be spaced L3 and L6.

  The longitudinal lengths L1 and L4 of the slit portions 23a and 24a are set to 300 mm to 1200 mm, the slit width L2 of the slit portion 23a is set to 0.2 mm to 2.0 mm, and the slit holes The distances L3 and L6 between adjacent end portions are set to 0.5 mm to 2.0 mm, the diameter D1 of the round hole 23b is set to 2 to 6 times the slit width L2, and the round hole 24b. The diameter D2 is set to 2 to 6 times the slit width L5.

  The slit width L5 of the slit portion 24a is difficult to be smaller than 0.2 mm due to processing problems, but is preferably as small as possible. This is because the flow width of the processing gas discharged from the discharge hole 24 is increased by narrowing the slit width L5, and the processing gas in the excited state reaches the surface of the substrate K before returning to the normal state. Because you can.

  The external electrode 26 is made of a metal film such as aluminum, and is provided in contact with the outer peripheral surface between the convex portion 22 a and the vicinity of the discharge hole 24 on both the left and right sides of the external dielectric 22. 27 is grounded.

  The holding member 27 is composed of a pair of two symmetrical members each having a cooling flow path 27a for allowing the coolant to flow. The holding member 27 is in contact with the outer peripheral surface of the external electrode 26 so that the external dielectric 22 is left and right. While sandwiching from both sides, the external dielectric 22 is held in a state where both ends protrude from the holding member 27 and the conductive member 29. The left and right holding members 27 are connected and fixed by a connecting member 28 attached to the upper surface thereof.

  The conductive member 29 is attached to both ends of the holding member 27 in the axial direction of the external dielectric 22 (that is, disposed at both ends of the external electrode 26 in the axial direction of the external dielectric 22). A flat mounting portion 30 having a coaxial through hole 30a, and fixed to the surface of the mounting portion 30, are formed in an arc shape with a distance from the outer peripheral surface of the external dielectric 22, and from the mounting portion 30 side. An inclined portion 31 that is inclined at an inclination angle θ with respect to the axis of the external dielectric 22 and is formed coaxially with the external dielectric 22 is provided so that the inner diameter increases as the distance from the axis of the external dielectric 22 increases. Thus, the outer peripheral surface of the external dielectric 22 is surrounded by the conductive member 29 (inclined portion 31) except for the lower portion thereof. The conductive member 29 is configured as a pair of two symmetrical members, and the inclination angle θ is set in a range of 2 ° to 30 °.

  The internal dielectric 35 is disposed inside the external dielectric 22 with its both ends protruding from both ends of the external dielectric 22, and one end is sealed by a sealing member 35a. The inner dielectric 35 is fixed between the inner peripheral surface of the outer dielectric 22 by a spacer (not shown) provided on the inner peripheral surface of the outer dielectric 22 at regular intervals in the axial direction of the outer dielectric 22. The gap is reliably formed and arranged. The gap between the inner dielectric 35 and the outer dielectric 22 is sealed by cylindrical sealing members 32 and 33 provided with one end abutting against the end surface of each flange 22b of the outer dielectric 22. Has been.

  As shown in FIGS. 1 to 3, 6, and 7, the internal electrode 36 is formed of a stainless steel tube or the like having one end sealed with a sealing member 37 a, and the internal dielectric 35 is disposed within the internal dielectric 35. A core material 37 disposed coaxially with the body 35, and a sheet-like member made of stainless steel and having a thickness of 20 μm to 50 μm, and a metal foil 38 wound around the outer peripheral surface of the core material 37 in a cylindrical shape. The metal foil 38 is configured to be deformed when an external force is applied, and to be restored to its original shape when the external force is removed (that is, to have a springback characteristic), and to recover the metal by a shape recovery action. The surface of the foil 38 is configured to contact the inner peripheral surface of the internal dielectric 35.

  As shown in FIG. 6, the core material 37 is inserted into the tube of the inner dielectric 35 after the metal foil 38 is wound so that the outer diameter thereof is smaller than the inner diameter of the inner dielectric 35. When the external force acting on the metal foil 38 is removed by being inserted into the tube of the internal dielectric 35, the outer diameter is increased by the spring back of the metal foil 38. The entire surface is brought into contact with the metal foil 38. One end of the core material 37 is located closer to the end of the external dielectric 22 than the external electrode 26, the holding member 27, and the conductive member 29.

  The high frequency power supply 39 is configured to apply a high frequency voltage between the core material 37 of the internal electrode 36 and the external electrode 26.

  As shown in FIGS. 1 to 3, 6, and 7, the coolant circulation mechanism 40 is disposed in the pipe of the core material 37, and one end and an outer peripheral surface of the coolant circulation mechanism 40 are provided at a distance from the inner surface of the core material 37. A metal wire 42 made of a pipe 41 and a stainless steel wire and spirally wound around the outer peripheral surface of the cooling tube 41 to ensure a constant interval between the inner peripheral surface of the core material 37 and the outer peripheral surface of the cooling tube 41. The other end of the core material 37 is connected, and the other end side of the cooling pipe 41 is provided therethrough, the first connection pipe 44 connected to the other end of the cooling pipe 41, and the core material 37 via the joint 43. A second connecting pipe 45 connected between the cooling pipe 41, a third connecting pipe (not shown) connected to one end side of the cooling flow path 27a of the holding member 27, and the other end side of the cooling flow path 27a. A fourth connecting pipe (not shown) connected to the first connecting pipe 44 and the third connecting pipe (see FIG. It supplies a coolant from without), and a circulating device 46 for returning the supplied cooling liquid second connecting pipe 45 and the fourth connecting pipe (not shown).

  As shown in FIG. 1 to FIG. 3 and FIG. 8, the gas supply mechanism 50 is introduced such that one end is sealed and the one end is disposed above the external dielectric 22 and parallel to the axis of the external dielectric 22. A pipe 51 and a processing gas generation device 52 that is connected to the other end of the introduction pipe 51 and includes a pressure swing adsorption (PSA) type nitrogen gas generation device or the like and generates a processing gas mainly containing nitrogen gas; A connecting member 53 having a top end connected to the inside of the pipe from the outer peripheral surface of the lower end on one end side of the introduction pipe 51, and a lower end connected to the upper surface of the protrusion 22 a of the external dielectric 22. A plurality of rectifying plates 54 each including a plurality of through-holes 54a formed of a flat plate-like and elongated member provided to be overlapped with the inside of the upper end side of the connection member 53 and vertically formed and arranged in a line in the longitudinal direction. Equipped with a process gas generator Introducing tube 51 from 52, the connecting member 53 (rectifying plate 54), supplying the process gas between the outer dielectric 22 and the inner dielectric 35 sequentially through the supply holes 23. A concave groove 53a is formed on the lower surface of the connection member 53 so as to surround the periphery of the supply hole 23, and a seal member 55 is disposed in the concave groove 53a. The connection part with the convex part 22a is kept airtight.

  According to the surface treatment apparatus 1 of the present example configured as described above, the process gas generated by the process gas generation device 52 of the gas supply mechanism 50 is supplied via the introduction pipe 51, the connection member 53, and the rectifying plate 54. When supplied between the external dielectric 22 and the internal dielectric 35 from the hole 23, the supplied processing gas flows between the external dielectric 22 and the internal dielectric 35 toward the discharge hole 24 side. To do.

  A high-frequency voltage is applied between the core material 37 of the internal electrode 36 and the external electrode 26 by a high-frequency power supply 39, and a high-frequency electric field is formed by the metal foil 38 (internal electrode 36) and the external electrode 26. The gas is turned into plasma containing radical atoms, ions, and the like by discharge generated between the metal foil 38 (internal dielectric 35) and the external electrode 26 (external dielectric 22) by the high-frequency electric field.

  Then, the plasma-ized processing gas is discharged to the outside from the discharge hole 24, and the surface of the substrate K transferred by the transfer roller 10 is processed by radical atoms and ions in the discharged processing gas (for example, Surface modification treatment, cleaning treatment, film formation treatment, etc. are performed).

  The holding member 27, the external electrode 26, the core material 37 of the internal electrode 36, and the metal foil 38 are supplied from the circulation device 46 of the coolant circulation mechanism 40, and the inside of the cooling channel 27 a, the core material 37, the cooling pipe 41, and the like. The quartz glass tube which is the outer dielectric 22 and the inner dielectric 35 is prevented from being broken by this.

  Further, the flow rate of the processing gas supplied from the supply hole 23 between the external dielectric 22 and the internal dielectric 35 is made uniform by the plurality of rectifying plates 54 provided in the connection member 53 of the gas supply mechanism 50. Thus, the plasma state between the outer dielectric 22 and the inner dielectric 35 is made uniform, and the discharge flow rate of the processing gas discharged from the discharge holes 24 is made uniform.

  As described above, in the processing gas discharge device 20 in the surface treatment apparatus 1 of the present example, the trumpet-shaped conductive member including the attachment portion 30 and the inclined portion 31 at both ends of the holding member 27 in the axial direction of the external dielectric 22. 29, and the outer dielectric 22 is surrounded by the conductive member 29 so that the distance between the outer dielectric 22 and the outer peripheral surface gradually increases. Therefore, as shown in FIG. It is possible to alleviate the concentration of the electric lines of force R at both ends of the holding member 27 (the surface of the mounting portion 30) so that the electric lines of force R are directed, and like the above-described conventional surface treatment apparatus, the holding member 27 can be relaxed. It is possible to prevent the lines of electric force R from concentrating at both ends of the (external electrode 26) and increasing the electric field in the vicinity of both ends.

  Thereby, it is possible to suppress the concentration of the discharge at the both end portions, to prevent local temperature rise of the external dielectric 22 and the internal dielectric 35 near the both ends due to the concentration of the discharge, and to the external dielectric 22. It is possible to prevent the internal dielectric 35 from being damaged.

  Note that the inclination angle θ of the inclined portion 31 with respect to the axis of the external dielectric 22 is preferably set in the range of 2 ° to 30 °. In this way, the concentration of electric lines of force can be effectively reduced. Concentration of discharge can be suppressed, and local temperature rise of the outer dielectric 22 and the inner dielectric 35 can be more effectively prevented. This is because, when the tilt angle θ is smaller than 2 °, the lines of electric force concentrate on the upper end of the tilted portion 31 in the tilt direction, and the electric discharge concentrates on the end, and the tilt angle θ is larger than 30 °. Since the lines of electric force concentrate on the lower end of the inclined portion 31 in the inclination direction (the root portion of the inclined portion 31) and the discharge concentrates on the end, the outer dielectric 22 and the inner dielectric 35 This is because a local temperature rise cannot be prevented.

  Further, the internal electrode 36 is constituted by a core material 37 and a metal foil 38 wound around the outer peripheral surface thereof, and the metal foil 38 is constituted so as to have spring back characteristics, and the surface of the metal foil 38 by the spring back. Is configured to abut against the inner peripheral surface of the internal dielectric 35, the internal electrode 36 (metal foil 38) can be completely brought into contact with the inner peripheral surface of the internal dielectric 35 without causing a gap. it can.

  As a result, it is possible to prevent discharge from occurring between the internal dielectric 35 and the internal electrode 36 and to prevent wasteful power consumption. The dielectric 35 can be cooled efficiently and uniformly, and the temperature rise of the internal dielectric 35 can be prevented to prevent the internal dielectric 35 from being damaged.

  The thickness of the metal foil 38 is preferably set in the range of 20 μm to 50 μm. In this way, it is possible to facilitate manufacturing and handling and to make it easy to wind in a cylindrical shape. This is because if the thickness is less than 20 μm, it is too thin to cause manufacturing problems and handling problems, and if the thickness is more than 50 μm, the strength is increased and it is difficult to wind the tube.

  Further, since the core material 37 and the cooling pipe 41 are configured in a double pipe structure, and the first connection pipe 44 and the second connection pipe 45 are connected to the other end side of the core material 37 and the cooling pipe 41, the internal dielectric 35 Maintenance can be efficiently performed from one side. In addition, unlike the case where the connecting pipes 44 and 45 are connected to both ends of the core member 37, it is not necessary to provide the space for arranging the connecting pipes on both sides of the internal dielectric 35, and only one side is required. It can also be made compact.

  In addition, since the supply hole 23 is composed of a plurality of slit holes formed in a line so that the longitudinal direction is along the axis of the external dielectric 22, the supply hole is slit compared to the case where the supply hole is composed of one slit hole. The length in the longitudinal direction per hole is shortened, the slit width L2 is easily processed to be constant, and the longitudinal direction of the slit hole (slit portion 23a) is easily processed in parallel with the axis of the external dielectric 22. The processing accuracy of the slit hole can be improved.

  As a result, the process gas supplied from the supply hole 23 between the external dielectric 22 and the internal dielectric 35 is made to be substantially uniform in the axial direction of the external dielectric 22 and discharged from the discharge hole 24. The gas flow rate can be made substantially uniform.

  Moreover, since the discharge hole 24 is composed of a plurality of slit holes formed in a row so that the longitudinal direction thereof is along the axis of the external dielectric 22, as in the case of the supply hole 23, the slit hole can be easily processed. The processing accuracy can be improved, and the flow rate of the processing gas in the axial direction of the external dielectric 22 discharged from the discharge hole 24 to the outside can be made substantially uniform.

  The lengths L1 and L4 in the longitudinal direction of the slit portions 23a and 24a are preferably set in the range of 300 mm to 1200 mm. In this way, the lengths of the slit portions 23a and 24a are preferable. The flow rate of the processing gas supplied from the supply hole 23 between the external dielectric 22 and the internal dielectric 35 or discharged to the outside from the discharge hole 24 can be made substantially uniform. This is because when the lengths L1 and L4 in the longitudinal direction of the slit portions 23a and 24a are shorter than 300 mm, it is not necessary to shorten the length per slit hole and provide a plurality of slit holes. This is because if the lengths L1 and L4 in the longitudinal direction of 24a are longer than 1200 mm, the slit holes cannot be processed with high accuracy.

  In addition, the slit width L2 of the slit portion 23a is preferably set in a range of 0.2 mm to 2.0 mm. In this way, it is possible to facilitate processing, or from the supply hole 23 to the external dielectric 22 and the inside. It is possible to easily adjust the flow rate and flow rate of the processing gas supplied to the dielectric 35. This causes a problem that processing becomes difficult when the slit width L2 is smaller than 0.2 mm, and when the slit width L2 is larger than 2.0 mm, the external dielectric 22 and the internal dielectric 35 are supplied from the supply hole 23. This is because it becomes difficult to adjust the flow rate and flow rate of the processing gas supplied between the two.

  Further, the distances L3 and L6 between the adjacent end portions of the slit holes are preferably set in the range of 0.5 mm to 2.0 mm, and this prevents the strength of the external dielectric 22 from being reduced. Or a portion where the processing gas is not supplied between the outer dielectric 22 and the inner dielectric 35 from the supply hole 23 or a portion where the processing gas is not discharged to the outside from the discharge hole 24 is narrowed, thereby causing unevenness in the flow rate of the processing gas. Can be reduced. This is because if the distances L3 and L6 between the end portions are smaller than 0.5 mm, the strength between the end portions is lowered and the risk of causing cracks and cracks increases. , L6 is larger than 2.0 mm, there are wide portions where the processing gas is not supplied from the supply hole 23 between the external dielectric 22 and the internal dielectric 35 and where the processing gas is not discharged outside from the discharge hole 24. This is because the unevenness of the processing gas flow rate becomes large.

  In addition, round holes 23b and 24b having diameters D1 and D2 larger than the slit widths L2 and L5 are formed at both ends in the longitudinal direction of the slit portions 23a and 24a, respectively, so as to alleviate stress concentration at the slit hole ends. Therefore, even if an impact is applied to the external dielectric 22, it is difficult to cause cracks or cracks at the end portions, and damage can be prevented, and handling can be facilitated. In addition, since the processing gas supplied or discharged from the round holes 23b and 24b does not supply processing gas or discharge processing gas, the processing gas flow in the portion between the slit holes is supplemented. The processing gas flow rate can be made uniform at a short distance from the hole 24.

  The diameters D1 and D2 of the round holes 23b and 24b are preferably set in the range of 2 to 6 times the slit widths L2 and L5. It is possible to prevent the dielectric 22 from being damaged, or to reduce the difference in flow rate of the processing gas between the slit portions 23a, 24a and the round holes 23b, 24b. This is because when the diameters D1 and D2 are smaller than twice the slit widths L2 and L5, the stress concentration is insufficiently relaxed and the external dielectric 22 is easily damaged, and the diameters D1 and D2 are the slit widths L2 and L5. Is larger than 6 times, the flow rate difference between the processing gas supplied or discharged from the slit portions 23a and 24a and the processing gas supplied or discharged from the round holes 23b and 24b becomes too large. Because.

  Therefore, according to the surface treatment apparatus 1 of this example, the processing gas discharge apparatus 20 prevents the local temperature rise of the external dielectric 22 and the internal dielectric 35 due to the concentration of discharge and prevents them from being damaged. In addition, it is possible to prevent discharge from occurring between the internal dielectric 35 and the internal electrode 36 to prevent wasteful power consumption, and to make the internal dielectric 35 efficient and uniform. The internal dielectric 35 can be prevented from being damaged by cooling, and further, the flow rate of the processing gas supplied between the external dielectric 22 and the internal dielectric 35 from the supply hole 23 and the discharge hole 24 to the outside. Since the flow rate of the discharged processing gas can be made uniform and the strength of the external dielectric 22 can be increased, the plasma surface treatment can be carried out uniformly and efficiently, the cost for the plasma surface treatment can be reduced, Simplification It is possible to achieve.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to this at all.

  In the above example, the outer peripheral surface excluding the lower portion of the external dielectric 22 is surrounded by the trumpet-shaped conductive member 29 with a space therebetween. However, the shape of the conductive member 29 depends on the shape of the external electrode 26. Can be changed as appropriate. For example, when the external electrode 26 is provided only on a part of the outer peripheral surface of the external dielectric 22, the conductive member 29 is provided only on a portion where the external electrode 26 exists in the circumferential direction of the external dielectric 22. It may be formed in an arc shape. Further, the conductive member 29 may be formed of a single member integrally with the external electrode 26, the holding member 27, and the like.

  In the above example, the substrate K is configured to be processed. However, the processing target is not limited to the substrate K, and the processing gas is not limited to the main component of nitrogen gas. Absent.

It is the front sectional view showing the schematic structure of the surface treatment apparatus concerning one embodiment of the present invention. It is sectional drawing of the arrow AA direction in FIG. It is sectional drawing of the arrow BB direction in FIG. It is the top view which showed schematic structure of the external dielectric material concerning this embodiment. FIG. 5 is a bottom view of the external dielectric shown in FIG. 4. It is explanatory drawing which showed schematic structure of the internal electrode which concerns on this embodiment. It is sectional drawing which showed schematic structure, such as an internal electrode and a cooling pipe which concerns on this embodiment. It is the bottom view which showed schematic structure of the connection member which concerns on this embodiment, and a baffle plate. It is explanatory drawing which showed the state of the electric line of force in this example. It is explanatory drawing which showed the state of the electric line of force in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface treatment apparatus 10 Conveyance roller 20 Processing gas discharge apparatus 21 Discharge mechanism 22 External dielectric 23 Supply hole 24 Discharge hole 26 External electrode 27 Holding member 29 Conductive member 30 Mounting part 31 Inclination part 35 Internal dielectric 36 Internal electrode 37 Core material 38 Metal foil 39 High frequency power supply 40 Coolant circulation mechanism 41 Cooling pipe 42 Metal wire 50 Gas supply mechanism 51 Introducing pipe 52 Process gas generator 53 Connecting member 54 Rectifying plate

Claims (3)

A processing gas discharge device comprising discharge means for converting a processing gas into plasma and discharging, and gas supply means for supplying the processing gas to the discharge means;
The discharge means is
An external dielectric made of a tubular member and having a supply hole to which the processing gas is supplied and a discharge hole for discharging the supplied processing gas opened on an outer peripheral surface;
An outer electrode provided on the outer peripheral surface of the external dielectric at a position that does not block the supply hole and the discharge hole, and is grounded;
An inner dielectric formed of a tubular member and provided in the outer dielectric tube so as to be spaced apart from the inner peripheral surface of the outer dielectric and coaxially with the outer dielectric;
An internal electrode provided in the internal dielectric tube;
Voltage application means for applying a voltage between the internal electrode and the external electrode,
The gas supply means is configured to supply the processing gas between the external dielectric and the internal dielectric from the supply hole,
The processing gas supplied between the external dielectric and the internal dielectric is turned into plasma by applying a voltage between the internal electrode and the external electrode by the voltage applying means, and then the discharge hole. In the processing gas discharge device configured to be discharged from the outside,
Conductive members disposed at both ends of the external electrode in the axial direction of the external dielectric and connected to the external electrodes, respectively, and the conductive member is connected to the external electrode in a circumferential direction of the external dielectric. The outer dielectric is formed in an arc shape at a distance from the outer peripheral surface of the external dielectric, and the inner diameter increases as the distance from the both ends of the external electrode in the axial direction of the external dielectric increases. And a processing gas discharge device, wherein the processing gas discharge device is inclined with respect to the axis of the external dielectric.   The processing gas discharge apparatus according to claim 1, wherein an inclination angle of the conductive member with respect to an axis of the external dielectric is 2 ° to 30 °. Support means for supporting the object to be treated;
The process gas discharge device according to claim 1 or 2,
The processing gas discharge device is disposed so that the discharge hole faces the processing object supported by the support means,
A surface treatment apparatus configured to treat the surface of the object to be treated with a treatment gas discharged from the treatment gas discharge apparatus.

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