JP2008071500A - Plasma generating device and work processing device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma generating device restraining corrosion inside a wave guide due to dew generation by humidity inside the wave guide when the wave guide becomes high temperature by thermal transmission generated at a plasma generating nozzle with plasma lighting and heat is emitted by putting off of the plasma, as well as a work processing device using it. <P>SOLUTION: The plasma generating device is provided with ventilation fans 45, 65 for ventilating inside a wave guide 10, and a temperature sensor 981 for detecting temperature of the wave guide 10. When temperature reaches a predetermined temperature or more by plasma generation, the ventilation fans 45, 65 are turned on for a predetermined time from putting off of light of the plasma so as the wave guide 10 to work as a wind tunnel to ventilate its inside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma generator capable of purifying or modifying the surface of a workpiece by irradiating plasma on a workpiece to be processed such as a substrate, and a workpiece processing apparatus using the plasma generator.

For example, there is known a workpiece processing apparatus that irradiates a workpiece to be processed such as a semiconductor substrate with plasma and removes organic contaminants on the surface, surface modification, etching, thin film formation, or thin film removal. For example, Patent Document 1 uses a plasma generation nozzle having concentric inner conductors and outer conductors, and applies a high-frequency pulse electric field between the two conductors to generate glow discharge instead of arc discharge. The plasma is generated, and a high-density plasma is generated by turning the processing gas from the gas supply source from the base end side to the free end side while swirling between both conductors, and is attached to the free end. There has been disclosed a plasma processing apparatus capable of obtaining high-density plasma at normal temperature and normal pressure by radiating from a nozzle to a workpiece.
JP 2003-197397 A

  According to the above-described prior art, plasma generation at normal temperature and normal pressure is possible, which is convenient for workpiece processing. On the other hand, in the prior art, a coaxial cable is used for the propagation of the microwave, and the high-power microwave cannot be propagated. It is necessary to use it. In addition, by using the waveguide, it is possible to efficiently propagate microwaves to a plurality of plasma generation nozzles. Therefore, when a waveguide is used for propagation of microwaves, while the plasma is lit by the plasma generation nozzle, the waveguide becomes hot due to heat conduction from the plasma generation nozzle, but when the light is turned off, heat is dissipated. As a result, there is a problem in that the inside of the waveguide becomes humid and dew condensation occurs, resulting in problems associated with the dew condensation such as corrosion of the waveguide.

  An object of the present invention is to provide a plasma generator and a work processing apparatus using the same, which can suppress the occurrence of problems associated with condensation in the waveguide in a configuration using a waveguide for microwave propagation. It is.

  The plasma generator of the present invention includes a microwave generating means for generating a microwave, a waveguide for propagating the microwave, a plasma attached to the waveguide, receiving the microwave, and plasma based on the energy. A plasma generation apparatus comprising a plasma generation nozzle that generates and discharges gas into gas, characterized in that it includes ventilation means for ventilating the inside of the waveguide.

  According to the above configuration, in order to cope with high-power plasma irradiation, large-area workpiece processing, etc., in the plasma generator in which the microwave from the microwave generating means is propagated through the waveguide, ventilation is performed. Means are provided to ventilate the waveguide.

  Therefore, when the plasma is turned on, the waveguide becomes hot due to the propagation of heat generated by the plasma generation nozzle, and when the heat is released by turning off the plasma, the inside of the waveguide becomes humid due to ventilation by the ventilation means. Can be prevented, and the occurrence of defects due to the condensation such as corrosion of the waveguide can be suppressed.

  In the plasma generator of the present invention, the ventilation means is provided on one end side and the other end side of the waveguide to allow ventilation into the waveguide and to prevent leakage of microwaves. And a ventilation fan provided on at least one of the one end side and the other end side of the waveguide and having the waveguide as a wind tunnel.

  According to the above configuration, ventilation for preventing dew condensation in the waveguide is first performed while preventing leakage of the microwave at a mesh interval sufficiently shorter than the wavelength of the microwave such as punching metal or wire mesh. This is realized by providing a mesh member that can be opened to the outside on one end side and the other end side of the waveguide. Next, a ventilation fan having the waveguide as a wind tunnel is provided on at least one of the one end side and the other end side of the waveguide.

  Therefore, for example, when the substantially straight waveguides are arranged vertically and the mesh members are provided at substantially both ends of the straight lines, the heated air in the waveguides is naturally convected from the upper mesh members by natural convection. When ventilation is possible by natural convection, such as when new cooling air is diffused and taken in from the lower mesh member, it is possible to ventilate only by providing the mesh member, For example, when the natural convection cannot be expected so much as in the case where the waveguide is horizontally disposed, condensation can be more reliably prevented by providing a ventilation fan and performing forced ventilation.

  Furthermore, the plasma generator of the present invention comprises a temperature sensor for detecting the temperature of the waveguide or the inside thereof, and a control means for controlling the driving of the ventilation fan in response to the detection result of the temperature sensor. It is further provided with the feature.

  According to the above configuration, the ventilation fan is not always driven, but a temperature sensor for detecting the temperature of the waveguide itself or the inside thereof is provided, and a control unit is provided. In response to the detection result of the temperature sensor, drive control of the ventilation fan is performed. Specifically, dew condensation does not occur during the temperature rise, so it is turned on only after the plasma is extinguished. Alternatively, it is turned on during plasma lighting so that the temperature is not raised so much that the temperature difference during cooling is reduced and condensation is unlikely to occur. If the humidity is detected and the humidity is very low, the possibility of condensation is small, so the ventilation fan may remain off. Furthermore, the higher the temperature in the waveguide, the higher the possibility that the plasma that should originally be lit by the nozzle will be lit in the waveguide, so when the temperature in the waveguide exceeds a predetermined temperature, A ventilation fan may be turned on to prevent plasma lighting.

  Therefore, the ventilation fan can be driven appropriately so that the condensation does not occur.

  The workpiece processing apparatus of the present invention further comprises a moving means for moving the workpiece and the plasma generating nozzle relative to each other on a plane intersecting the plasma irradiation direction in the plasma generating apparatus. And performing a predetermined treatment by irradiating the workpiece with plasma.

  According to the above configuration, the plasma generating apparatus includes the moving unit that relatively moves the workpiece and the plasma generating nozzle on a surface that intersects the plasma irradiation direction, and transports the workpiece to be processed. On the other hand, in the workpiece processing apparatus that continuously irradiates the workpiece with plasma and applies predetermined processing continuously, by using the plasma generator provided with a ventilation means for ventilating the inside of the waveguide, It is possible to realize a work processing apparatus that can suppress the occurrence of defects due to condensation.

  As described above, the plasma generating apparatus of the present invention propagates microwaves from the microwave generating means through the waveguide in order to cope with high-power plasma irradiation, large-area workpiece processing, and the like. In the plasma generator, ventilation means is provided to ventilate the inside of the waveguide.

  Therefore, when the plasma is turned on, the waveguide is heated due to the propagation of heat generated by the plasma generation nozzle, and when the heat is released by turning off the plasma, the inside of the waveguide becomes humid due to ventilation by the ventilation means. It is possible to prevent the occurrence of condensation, and to suppress the occurrence of problems associated with the condensation such as corrosion of the waveguide.

  In addition, as described above, the workpiece processing apparatus of the present invention includes a moving unit that relatively moves the workpiece and the plasma generation nozzle on a plane that intersects the plasma irradiation direction, In the workpiece processing apparatus in which the workpiece is irradiated with plasma and continuously subjected to a predetermined process while being conveyed, the plasma generator described above is provided which has ventilation means for ventilating the inside of the waveguide.

  Therefore, it is possible to realize a work processing apparatus that can suppress the occurrence of defects due to condensation in the waveguide.

  FIG. 1 is a perspective view showing an overall configuration of a work processing apparatus S according to an embodiment of the present invention. The workpiece processing apparatus S includes a plasma generating unit PU (plasma generating apparatus) that generates plasma and irradiates the workpiece W as a workpiece with the plasma, and a predetermined route that passes the workpiece W through the plasma irradiation region. It is comprised from the conveyance means C conveyed by. 2 is a perspective view of the plasma generation unit PU in which the line-of-sight direction is different from that in FIG. 1, and FIG. 3 is a partially transparent side view. 1 to 3, the XX direction is the front-rear direction, the Y-Y direction is the left-right direction, the ZZ direction is the up-down direction, the -X direction is the front direction, the + X direction is the rear direction,- Y will be described as a left direction, + Y direction as a right direction, -Z direction as a downward direction, and + Z direction as an upward direction.

  The plasma generation unit PU is a unit capable of generating plasma at room temperature and normal pressure using microwaves. In general, the waveguide 10 propagates microwaves, and one end side of the waveguide 10. A microwave generator 20 that generates a microwave having a predetermined wavelength disposed on the (left side), a plasma generator 30 provided in the waveguide 10, and a microwave disposed on the other end side (right side) of the waveguide 10 The dummy load 40 to absorb, the circulator 50 that separates the reflected microwave out of the microwave emitted to the waveguide 10 so as not to return to the microwave generator 20, and the dummy load that absorbs the reflected microwave separated by the circulator 50. 60, a stub tuner 70 for matching impedance between the waveguide 10 and the plasma generating nozzle 31, and a blower fan 80 for ventilating the inside of the waveguide 10. Equipped and are configured. The conveying means C includes a conveying roller C1 that is rotationally driven by a driving means (not shown). In the present embodiment, an example in which a flat workpiece W is conveyed by the conveying means C is shown.

  The waveguide 10 is made of a nonmagnetic metal such as aluminum, has a long tubular shape with a rectangular cross section, and propagates the microwave generated by the microwave generator 20 toward the plasma generator 30 in the longitudinal direction thereof. Is. The waveguide 10 is composed of a connected body in which a plurality of divided waveguide pieces are connected to each other by flange portions, and the first conductor on which the microwave generator 20 is mounted in order from one end side. The wave tube piece 11, the second waveguide piece 12 to which the stub tuner 70 is assembled, and the third waveguide piece 13 provided with the plasma generator 30 are connected. A circulator 50 is interposed between the first waveguide piece 11 and the second waveguide piece 12, and a dummy load 40 is connected to the other end side of the third waveguide piece 13.

  The first waveguide piece 11, the second waveguide piece 12, and the third waveguide piece 13 are each formed into a rectangular tube shape using an upper plate, a lower plate, and two side plates made of a metal flat plate. It is assembled and flange plates are attached to both ends thereof. In addition, you may make it use the rectangular waveguide piece formed by extrusion molding, the bending process of a plate-shaped member, etc., or a non-dividing type | mold waveguide irrespective of the assembly of such a flat plate. In addition, the waveguide is not limited to a rectangular cross section, and for example, a waveguide having an elliptical cross section can be used. Furthermore, not only a nonmagnetic metal but a waveguide can be comprised with the various members which have a waveguide effect | action.

  The microwave generator 20 includes, for example, an apparatus main body portion 21 including a microwave generation source such as a magnetron that generates a microwave of 2.45 GHz, and the microwave generated by the apparatus main body portion 21 inside the waveguide 10. And a microwave transmission antenna 22 that emits light to the outside. In the plasma generation unit PU according to the present embodiment, for example, a continuously variable microwave generator 20 that can output microwave energy of 1 W to 3 kW is preferably used.

  As shown in FIG. 3, the microwave generation device 20 has a configuration in which a microwave transmission antenna 22 protrudes from the device main body 21, and is fixed in a mode of being placed on the first waveguide piece 11. Has been. Specifically, the apparatus main body 21 is placed on the upper surface plate 11U of the first waveguide piece 11, and the microwave transmitting antenna 22 is inside the first waveguide piece 11 through the through hole 111 formed in the upper surface plate 11U. The waveguide space 110 is fixed so as to protrude. With this configuration, the microwave of 2.45 GHz, for example, emitted from the microwave transmission antenna 22 is directed from one end side (left side) to the other end side (right side) by the waveguide 10. Propagated.

The plasma generation unit 30 includes eight plasma generation nozzles 31 that are arranged in a row in the left-right direction on the lower surface plate 13B of the third waveguide piece 13 (the surface facing the workpiece to be processed). Configured. The width of the plasma generation unit 30, that is, the arrangement width in the left-right direction of the eight plasma generation nozzles 31 is a width that substantially matches the size t in the width direction orthogonal to the conveying direction of the flat workpiece W. Thereby, the plasma processing can be performed on the entire surface of the workpiece W (the surface facing the lower surface plate 13B) while the workpiece W is conveyed by the conveying roller C1. The arrangement interval of the eight plasma generating nozzles 31 is preferably determined according to the wavelength lambda _G of the microwave propagating through the waveguide 10. For example, it is desirable to arrange the plasma generating nozzles 31 at a ½ pitch and a ¼ pitch of the wavelength λ _{G. When} a microwave of 2.45 GHz is used, since λ _G = 230 mm, 115 mm (λ _G / 2) The plasma generating nozzles 31 may be arranged at a pitch or 57.5 mm (λ _G / 4) pitch.

  4 is an enlarged side view showing two plasma generation nozzles 31 (one plasma generation nozzle 31 is drawn as an exploded view), and FIG. 5 is a cross-sectional view taken along line AA in FIG. The plasma generating nozzle 31 includes a central conductor 32 (inner conductor), a nozzle body 33 (outer conductor), a nozzle holder 34, a seal member 35, and a protective tube 36.

  The center conductor 32 is made of a highly conductive metal such as copper, aluminum, or brass, and is made of a rod-shaped member having a diameter of about 1 to 5 mm. The vertical direction is such that the lower end 322 is substantially flush with the lower end edge 331 of the nozzle body 33 while penetrating and projecting to the waveguide space 130 by a predetermined length (this projecting portion is referred to as a receiving antenna unit 320). Is arranged. Microwave energy (microwave power) is applied to the central conductor 32 when the receiving antenna unit 320 receives the microwave propagating through the waveguide 10. The central conductor 32 is held by a seal member 35 at a substantially intermediate portion in the length direction.

  The nozzle body 33 is a cylindrical body made of a highly conductive metal and having a cylindrical space 332 that houses the central conductor 32. The nozzle holder 34 is also made of a highly conductive metal, and has a relatively large-diameter lower holding space 341 that holds the nozzle body 33 and a relatively small-diameter upper holding space 342 that holds the seal member 35. It is a state. On the other hand, the seal member 35 is made of a heat-resistant resin material such as Teflon (registered trademark) or an insulating member such as ceramic, and has a holding hole 351 for holding the central conductor 32 fixedly on its central axis. It consists of a body.

  The nozzle body 33 is provided in an annularly projecting manner from the upper side, an upper body part 33U fitted in the lower holding space 341 of the nozzle holder 34, an annular recess 33S for holding a gas seal ring 37 described later. A flange portion 33F and a lower body portion 33B protruding from the nozzle holder 34 are provided. In addition, a communication hole 333 for supplying a predetermined processing gas to the cylindrical space 332 is formed in the upper body portion 33U.

  The nozzle body 33 functions as an external conductor disposed around the central conductor 32. The central conductor 32 is a cylindrical space with a predetermined annular space H (insulation interval) secured around it. It is inserted on the central axis of 332. The nozzle body 33 has a nozzle holder such that the outer peripheral portion of the upper body portion 33U is in contact with the inner peripheral wall of the lower holding space 341 of the nozzle holder 34 and the upper end surface of the flange portion 33F is in contact with the lower end edge 343 of the nozzle holder 34. 34 is fitted. The nozzle body 33 is preferably attached to the nozzle holder 34 with a detachable fixing structure using, for example, a plunger or a set screw.

  The nozzle holder 34 includes an upper body portion 34U (corresponding approximately to the position of the upper holding space 342) and a lower surface plate 13B that are closely fitted in a through hole 131 formed in the lower surface plate 13B of the third waveguide piece 13. And a lower body portion 34B (substantially corresponding to the position of the lower holding space 341). A gas supply hole 344 for supplying a processing gas to the annular space H is formed in the outer periphery of the lower body portion 34B. Although not shown, a pipe joint or the like for connecting a terminal portion of a gas supply pipe for supplying a predetermined processing gas is attached to the gas supply hole 344. The gas supply hole 344 and the communication hole 333 of the nozzle body 33 are set so that they are in communication with each other when the nozzle body 33 is fitted into the nozzle holder 34 at a fixed position. A gas seal ring 37 is interposed between the nozzle body 33 and the nozzle holder 34 in order to suppress gas leakage from the abutting portion between the gas supply hole 344 and the communication hole 333.

  A plurality of the gas supply holes 344 and the communication holes 333 may be perforated at equal intervals in the circumferential direction, and are not perforated in the radial direction toward the center. The gas may be perforated in the tangential direction of the outer peripheral surface of the cylindrical space 332 so as to swirl the gas. Further, the gas supply hole 344 and the communication hole 333 are not perpendicular to the central conductor 32, and may be formed obliquely from the upper end 321 side to the lower end 322 side in order to improve the flow of the processing gas. Good.

  The seal member 35 has a lower end edge 352 in contact with an upper end edge 334 of the nozzle body 33 and an upper end edge 353 in contact with an upper end locking portion 345 of the nozzle holder 34 in the upper holding space 342 of the nozzle holder 34. Is retained. That is, the upper holding space 342 is assembled so that the seal member 35 supporting the central conductor 32 is fitted and the lower end edge 352 of the nozzle body 33 is pressed by the upper end edge 334. is there.

  The protective tube 36 (not shown in FIG. 5) is made of a quartz glass pipe or the like having a predetermined length, and has an outer diameter substantially equal to the inner diameter of the cylindrical space 332 of the nozzle body 33. The protective tube 36 has a function of preventing abnormal discharge (arcing) at the lower end edge 331 of the nozzle body 33 and radiating a plume P to be described later normally. The cylindrical space 332 is inserted so as to protrude from the edge 331. Note that the entire protective tube 36 may be accommodated in the cylindrical space 332 so that the tip end thereof coincides with the lower end edge 331 or enters the inner side of the lower end edge 331.

  As a result of the plasma generation nozzle 31 being configured as described above, the nozzle body 33, the nozzle holder 34, and the third waveguide piece 13 (waveguide 10) are in a conductive state (the same potential), Since the central conductor 32 is supported by the insulating seal member 35, it is electrically insulated from these members. Therefore, as shown in FIG. 6, when the microwave is received by the receiving antenna unit 320 of the central conductor 32 and the microwave power is supplied to the central conductor 32 in a state where the waveguide 10 is at the ground potential. An electric field concentration portion is formed in the vicinity of the lower end portion 322 and the lower end edge 331 of the nozzle body 33.

  In this state, when an oxygen-based processing gas such as oxygen gas or air is supplied from the gas supply hole 344 to the annular space H, the processing gas is excited by the microwave power and the lower end of the central conductor 32 is excited. Plasma (ionized gas) is generated near the portion 322. Although this plasma has an electron temperature of tens of thousands of degrees, the gas temperature is a reactive plasma that is close to the outside temperature (a plasma in which the electron temperature indicated by electrons is extremely high compared to the gas temperature indicated by neutral molecules). It is a plasma generated under normal pressure.

  The processing gas thus converted into plasma is radiated from the lower edge 331 of the nozzle body 33 as a plume P by the gas flow provided from the gas supply hole 344. This plume P contains radicals. For example, when an oxygen-based gas is used as the processing gas, oxygen radicals are generated, and the plume P having an organic substance decomposition / removal action, a resist removal action, and the like can be obtained. In the plasma generation unit PU according to the present embodiment, since a plurality of plasma generation nozzles 31 are arranged, it is possible to generate a line-shaped plume P extending in the left-right direction.

  Incidentally, when an inert gas such as argon gas or nitrogen gas is used as the processing gas, the surface cleaning and surface modification of various substrates can be performed. Further, if a compound gas containing fluorine is used, the substrate surface can be modified to a water-repellent surface, and using a compound gas containing a hydrophilic group can modify the substrate surface to a hydrophilic surface. Furthermore, if a compound gas containing a metal element is used, a metal thin film layer can be formed on the substrate.

  The dummy loads 40 and 60 are water-cooled (or air-cooled) radio wave absorbers that absorb microwaves that are not received by the respective plasma generation nozzles 31 and convert them into heat. These dummy loads 40 and 60 are provided with cooling water circulation ports 41 and 61 for circulating cooling water therein, and heat generated by heat conversion of microwaves is exchanged with the cooling water. It has come to be.

  The circulator 50 is composed of, for example, a waveguide-type three-port circulator with a built-in ferrite column. Of the microwaves once propagated toward the plasma generator 30, the plasma generator 30 returns without being consumed. The incoming reflected microwave is directed to the dummy load 60 without returning to the microwave generator 20. By arranging such a circulator 50, the microwave generator 20 is prevented from being overheated by the reflected microwave.

  The stub tuner 70 is for impedance matching between the waveguide 10 and the plasma generation nozzle 31, and has three stub tuners arranged in series on the upper surface plate 12 U of the second waveguide piece 12 at a predetermined interval. Units 70A to 70C are provided. The three stub tuner units 70 </ b> A to 70 </ b> C have the same structure, and as shown in FIG. 3, the stub 71 projecting into the waveguide space 120 of the second waveguide piece 12 is moved up and down in the vertical direction. The power consumption by the conductor 32 is maximized, that is, the reflected microwave is minimized, so that plasma ignition is easily generated.

  The conveying means C includes a plurality of conveying rollers C1 arranged along a predetermined conveying path, and the conveying roller C1 is driven by an unillustrated driving means, so that the workpiece W to be processed is generated by the plasma generation. It is conveyed via the section 30. Here, examples of the workpiece W to be processed include a flat substrate such as a plasma display panel and a semiconductor substrate, a circuit substrate on which electronic components are mounted, and the like. Also, parts or assembled parts that are not flat-shaped can be processed, and in this case, a belt conveyor or the like may be employed instead of the conveying roller.

In the workpiece processing apparatus S configured as described above, it should be noted that in the present embodiment, the dummy load 60 which is substantially one end side of the straight waveguide 10 and the dummy which is the other end side. Ventilation fans 65 and 45 for ventilating the inside of the waveguide 10 are provided at the tip of at least one of the loads 40 (both in the present embodiment). Correspondingly, as shown in the exploded perspective view of FIG. 1, the end plates 62 and 42 covering the tips of the dummy loads 60 and 40 are made of mesh members such as punching metal or wire mesh, has 43, the width of a number of openings thereof, less than 1/2 of a wavelength lambda _G of the microwave is preferably made shorter to 1/8 or less, the leakage of microwave is prevented. The said end plates 62 and 42 and the ventilation fans 65 and 45 comprise a ventilation means. The ventilation fans 65 and 45 may be provided on the inner side (upstream in the microwave propagation direction) side of the dummy loads 60 and 40. However, the ventilation fans 65 and 45 may be provided on the outer side (downstream) side. The influence of the microwaves on the ventilation fans 65 and 45 can be reduced, which is preferable.

  The ventilation fan 65 provided at substantially one end side of the waveguide 10 may be provided at the end portion of the first waveguide piece 11 on which the microwave generator 20 is mounted. However, if a corresponding opening is provided in the cylindrical portion of the waveguide 10, the path of the microwave current traveling in a spiral manner through the straight cylindrical waveguide 10 is interrupted. It is preferably provided on the end plate of the cylindrical waveguide 10. Further, the ventilation direction by the ventilation fans 65 and 45 is preferably such that the ventilation fan 45 is on the suction side and the ventilation fan 65 is on the discharge side. As a result, the air is ventilated through the route of the ventilation fan 45, the dummy load 40, the plasma generator 30, the stub tuner 70, the circulator 50, the dummy load 60, and the ventilation fan 65. The generation nozzle 31 can be cooled.

  With this configuration, in order to cope with high-power plasma irradiation, large-area workpiece processing, and the like, when the microwave from the microwave generator 20 propagates through the waveguide 10, the ventilation is performed. When the inside of the waveguide 10 is ventilated by the fans 65 and 45, when the plasma is turned on, the temperature of the waveguide 10 becomes high due to the propagation of heat generated by the plasma generation nozzle 31, and when the heat is released by the plasma extinguishing. In addition, it is possible to prevent the inside of the waveguide 10 from becoming humid and to cause dew condensation, and it is possible to suppress the occurrence of problems associated with the dew condensation such as corrosion of the waveguide 10.

  Further, for example, when the substantially straight waveguide 10 is vertically disposed and the mesh members are provided at substantially both ends of the straight line, the heated air in the waveguide 10 is moved upward by natural convection. When ventilation is possible by natural convection, such as when new cooling air is dissipated from the mesh member and taken from the mesh member below, ventilation can be performed simply by providing the mesh member. However, by providing the ventilation fans 65 and 45 with the waveguide 10 as a wind tunnel and performing forced ventilation, the natural convection cannot be expected so much as when the waveguide 10 is disposed horizontally, for example. In this case, it is possible to prevent condensation more reliably.

  Furthermore, the cooling is performed by ventilating the waveguide 10 to suppress the plasma lighting in the waveguide 10 as indicated by the reference symbol P ′ in FIG. 6, and the lighting on the plasma generating nozzle 31 side. Can be performed with a higher probability. Accordingly, it is possible to suppress the occurrence of problems due to plasma lighting in the waveguide 10 such as wear of the receiving antenna unit 320 and damage to the seal member 35 that is an insulating support of the receiving antenna 320.

  Next, an electrical configuration of the work processing apparatus S according to the present embodiment will be described. FIG. 7 is a block diagram showing a control system of the work processing apparatus S. This control system includes a CPU (central processing unit) 901 and an overall control unit 90 including its peripheral circuits, a microwave output control unit 91 including an output interface and a drive circuit, a gas flow rate control unit 92, and conveyance control. Unit 93 and fan drive unit 99, a display unit, an operation panel, and the like, an operation unit 95 for giving a predetermined operation signal to the overall control unit 90, and a sensor comprising an input interface, an analog / digital converter, An input unit 96, 97, 98, sensors 961, 971, 981, a drive motor 931, and a flow control valve 923 are configured.

  The microwave output control unit 91 performs ON / OFF control and output intensity control of the microwave output from the microwave generator 20. The microwave output controller 91 generates the 2.45 GHz pulse signal and The operation control of the microwave generation by the apparatus main body 21 is performed.

  The gas flow rate control unit 92 controls the flow rate of the processing gas supplied to each plasma generation nozzle 31 of the plasma generation unit 30. Specifically, the opening degree of the flow rate control valve 923 provided in the gas supply pipe 922 connecting the processing gas supply source 921 such as a gas cylinder and each plasma generation nozzle 31 is adjusted.

  The conveyance control unit 93 controls the operation of the drive motor 931 that rotationally drives the conveyance roller C1, and controls the start / stop of conveyance of the workpiece W, the conveyance speed, and the like. The fan drive unit 99 performs ON / OFF control of the ventilation fans 45 and 65.

  The overall control unit 90 is responsible for overall operation control of the work processing apparatus S. The measurement result of the flow rate sensor 961 input from the sensor input unit 96 according to the operation signal given from the operation unit 95, the sensor The measurement result of the conveyance speed of the workpiece W by the speed sensor 971 input from the input unit 97 and the measurement result of the temperature sensor 981 input from the sensor input unit 98 are monitored, and the microwave output control unit 91 and the gas flow rate control are performed. Operations of the unit 92, the conveyance control unit 93, and the fan drive unit 99 are controlled based on a predetermined sequence.

  Specifically, the CPU 901 starts the conveyance of the workpiece W based on a control program stored in advance in the memory 902, guides the workpiece W to the plasma generation unit 30, and generates a processing gas having a predetermined flow rate for each plasma. Plasma (plume P) is generated by supplying microwave power while being supplied to the nozzle 31, and the plume P is radiated on the surface of the workpiece W while it is being conveyed. The size of the plume P can be controlled by controlling the microwave power and the processing gas flow rate, and the irradiation amount of the plume P can be controlled by controlling the conveyance speed. In this way, a plurality of workpieces W are continuously processed.

  At this time, it should be noted that the CPU 901 as the control means does not always keep the ventilation fans 45 and 65 driven, but as shown in FIG. 1 and FIG. The output from the temperature sensor 981 attached to the side wall 13S of the three waveguide pieces 13 is monitored via the sensor input unit 98, and ON / OFF control of the ventilation fans 45 and 65 is performed according to the detection result. Do. For example, when the temperature exceeds 40 ° C., the ventilation fans 45 and 65 are turned on so that the temperature in the waveguide 10 is not increased so much when the plasma is turned on. Can be difficult. This also makes it possible to suppress plasma lighting in the waveguide 10 as indicated by the reference symbol P ′, which is more likely to occur as the temperature in the waveguide 10 increases.

  As a method for driving the ventilation fans 45 and 65, dew condensation does not occur during the temperature rise, so it may be turned on only after the plasma is extinguished, or when the temperature exceeds 40 ° C. and after the plasma is extinguished. It may be turned ON at a predetermined time. Furthermore, if the humidity is detected and the humidity is very low, the possibility of condensation is small, so the ventilation fan may be kept off. In this manner, the ventilation fans 45 and 65 can be appropriately driven so that the condensation does not occur.

  In JP-A-62-264623, a microwave is propagated through a waveguide, and a microwave transmission window made of quartz or ceramic is provided at the end of the microwave perpendicular to the traveling direction of the microwave. In the microwave plasma processing apparatus in which the opposite side is a chamber to be processed through the microwave transmitting window, the workpiece to be processed is arranged, and the processing gas is supplied, a gas is blown to the center of the microwave transmitting window. It is described that it is attached and cooled. However, this conventional technique cools the microwave emission port and does not cool the waveguide, and condensation in the waveguide, which is the subject of the present invention, still occurs.

  A workpiece processing apparatus and a plasma generation apparatus according to the present invention include an etching processing apparatus and a film forming apparatus for a semiconductor substrate such as a semiconductor wafer, a glass substrate such as a plasma display panel and a cleaning processing apparatus for a printed board, and a sterilization process for medical equipment. The present invention can be suitably applied to an apparatus, a protein decomposition apparatus, and the like.

It is a perspective view which shows the whole structure of the workpiece processing apparatus which concerns on this invention. FIG. 2 is a perspective view of a plasma generation unit with a different line-of-sight direction from FIG. 1. It is a partial see-through | perspective side view of a workpiece | work processing apparatus. It is a side view which expands and shows two plasma generation nozzles (one plasma generation nozzle is drawn as an exploded view). It is the sectional view on the AA line side of FIG. It is a see-through | perspective side view for demonstrating the generation state of the plasma in a plasma generation nozzle. It is a block diagram which shows the control system of a workpiece | work processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Waveguide 20 Microwave generator 30 Plasma generating part 31 Plasma generating nozzle 32 Central conductor 33 Nozzle main body 34 Nozzle holder 344 Gas supply hole 40, 60 Dummy load 41, 61 Cooling water circulation port 42, 62 End plate 43, 63 Opening 45, 65 Ventilation fan 50 Circulator 70 Stub tuner 90 Overall control unit 901 CPU
902 Memory 91 Microwave output control unit 92 Gas flow rate control unit 921 Processing gas supply source 922 Gas supply pipe 923 Flow rate control valve 93 Transport control unit 931 Drive motor 95 Operation units 96, 97, 98 Sensor input unit 981 Temperature sensor 99 Fan drive Part S Work processing unit PU Plasma generation unit C Conveying means C1 Conveying roller W Workpiece

Claims (4)

Microwave generating means for generating a microwave, a waveguide for propagating the microwave, and a microwave attached to the waveguide for receiving the microwave and generating a plasma gas based on the energy. In the plasma generator configured to include a plasma generating nozzle that
A plasma generator comprising a ventilation means for ventilating the inside of the waveguide. The ventilation means is
A mesh member provided on one end side and the other end side of the waveguide, allowing ventilation into the waveguide and preventing leakage of microwaves;
2. The plasma generating apparatus according to claim 1, further comprising a ventilation fan provided on at least one of the one end side and the other end side of the waveguide and having the waveguide as a wind tunnel. A temperature sensor for detecting the temperature of the waveguide or the inside thereof;
The plasma generating apparatus according to claim 2, further comprising a control unit that performs drive control of the ventilation fan in response to a detection result of the temperature sensor.   The plasma generating apparatus according to any one of claims 1 to 3, further comprising a moving unit that relatively moves the workpiece and the plasma generating nozzle on a surface intersecting with the plasma irradiation direction. A workpiece processing apparatus for performing predetermined processing by irradiating the workpiece with plasma while performing smooth movement.

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