JP2007227069A - Method and device for generating plasma, and workpiece treatment device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform an efficient plasma treatment while obtaining a stable plume in each of a plurality of plasma generating nozzles in treatment of a plurality of workpieces or a large-area workpiece in a plasma generating device used for workpiece treatment such as modification of a substrate, which comprises the plurality of plasma generating nozzles provided on a waveguide. <P>SOLUTION: A CPU 901 of an entire control part 90 measures and monitors the gas flow rate supplied from a treatment gas supply source 921 to each plasma generating nozzle 31 by a flow sensor 961, and a memory 903 stores plasma output characteristics such as sizes or shapes of plume and plasma temperatures corresponding to respective levels of the gas flow rate. The CPU reads the characteristics and performs feedback control of each flow control valve 923 so as to attain a desired characteristic. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

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, thereby generating 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. A plasma processing apparatus is disclosed in which high-density plasma can be obtained under normal pressure by radiating a workpiece to be processed from a nozzle.
JP 2003-197397 A

  However, in the above-described prior art, only a single plasma generation nozzle is shown. When processing a large-area workpiece or a plurality of workpieces to be processed, how to use a plurality of plasma generation nozzles? It cannot be imagined whether a stable plume can be obtained.

  An object of the present invention is to provide a plasma generation method and apparatus capable of obtaining a stable plume for a plurality of workpieces or workpieces having a large area, and capable of performing plasma treatment efficiently, and the same. It is to provide a work processing apparatus to be used.

  The plasma generator according to the present invention generates a microwave that generates microwaves, a waveguide that propagates the microwaves, a gas that receives the microwaves, and generates plasma based on the energy of the microwaves. A plasma generation device comprising a plasma generation unit attached to the waveguide, wherein a plurality of the plasma generation nozzles are attached to the waveguide, Measuring means for measuring the characteristics of the gas supplied from the supply source to each plasma generating nozzle; storage means for storing in advance plasma output characteristics corresponding to the characteristics of each gas in each plasma generating nozzle; The plasma output characteristic corresponding to the measurement result of the measurement means is read from the storage means, and based on the read result, the Characterized in that it comprises a control means for controlling at least one of the microwave generating unit and the gas supply source.

  Further, the plasma generation method of the present invention propagates the microwave generated by the microwave generation means through the waveguide, receives the microwave by the plasma generation nozzle, and generates plasmaized gas. In the plasma generation method to be released, a plurality of the plasma generation nozzles are arranged and attached to the waveguide of the plasma generation unit, and plasma output characteristics corresponding to the characteristics of each gas in each plasma generation nozzle are stored in advance. Each of the plasma generation nozzles is monitored by measuring the characteristics of the gas supplied from the gas supply source to each plasma generation nozzle and reading the plasma output characteristics corresponding to the measurement results. It is characterized by.

  According to the above configuration, in the plasma generating apparatus that can be used for workpiece processing such as substrate modification, a plurality of plasma generating nozzles are arranged and attached to the waveguide. When dealing with large-area workpieces, etc., measure the characteristics of the gas supplied from the gas supply source to each plasma generation nozzle, such as the flow rate, flow velocity, type, and mixing ratio, using a measuring device. To do. On the other hand, the storage means stores the plasma output characteristics corresponding to the characteristics of each gas in each plasma generating nozzle. For example, at a certain flow rate, the plume size and shape are changed, and the plasma temperature is determined. Measurement results on the manufacturer side, such as whether or not, are stored in advance. If there are a plurality of types of plasma generating nozzle shapes, the storage means stores the plasma output characteristics corresponding to the types. Then, the control means reads out the plasma output characteristic corresponding to the measurement result of the measurement means from the storage means, and performs feedback control of at least one of the microwave generation means and the gas supply source based on the read result. . For example, the flow rate is increased when the plume is increased, and the flow rate is decreased when the plasma temperature is increased.

  Therefore, a stable plume can be obtained with each of the plurality of plasma generating nozzles, and plasma processing can be performed uniformly and efficiently on the plurality of workpieces to be processed and workpieces having a large area.

  Furthermore, in the plasma generating apparatus of the present invention, the gas characteristic is a gas flow rate, and the control unit is configured such that the flow rate of the gas supplied to the at least one plasma generation nozzle by the measuring unit is a predetermined value. The microwave generating means is stopped when it is measured that

  According to the above configuration, the control means is configured so that the flow rate of the gas supplied to all the plasma generation nozzles exceeds a predetermined value and the gas supply from the gas supply source is normally performed by the measurement means. If it is measured, the microwave is generated by the microwave generating means, and the flow rate of the gas supplied to at least one plasma generating nozzle becomes a predetermined value or less, and the gas from the gas supply source When it is measured that the supply of power is stopped, an interlock operation is performed to stop the microwave generation means.

  Therefore, it is possible to prevent the plasma generating nozzle from becoming an abnormally high temperature.

  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 generation unit including the plurality of plasma generation nozzles in the waveguide includes the moving unit that relatively moves the plasma generation unit and the workpiece, and conveys the workpiece to be processed. On the other hand, in the work processing apparatus that continuously irradiates the work with plasma and applies predetermined processing continuously, the plasma output characteristic is monitored by the measuring means, and the control means is the microwave generating means based on the measurement result By using the above-described plasma generator that feedback-controls at least one of the gas supply source and the gas supply source, a workpiece processing apparatus that can stably and efficiently process a workpiece can be realized.

  As described above, the plasma generation method and apparatus of the present invention is a plasma generation apparatus that can be used for workpiece processing, such as substrate modification, and a plurality of plasma generation nozzles are arranged and attached to a waveguide. In dealing with a plurality of workpieces and large-area workpieces, the characteristics of the gas supplied from the gas supply source to each plasma generation nozzle, such as flow rate, flow rate, type, and mixing ratio, While the measurement means measures and monitors each, the storage means shows the plasma output characteristics corresponding to the characteristics of each gas in each plasma generating nozzle, for example, the plume size and shape at a certain flow rate. The measurement results on the manufacturer side, such as how much the temperature of the plasma is, are stored in advance, and the control means measures the measurement results of the measurement means. Reads the corresponding plasma output characteristic from the storage means, on the basis of the read-out result, feedback control of the at least one of said microwave generating means and the gas source.

  Therefore, a stable plume can be obtained with each of the plurality of plasma generating nozzles, and plasma processing can be performed uniformly and efficiently on the plurality of workpieces to be processed and workpieces having a large area.

  In addition, as described above, the workpiece processing apparatus of the present invention includes a moving unit that moves the workpiece and the plasma generating nozzle relative to each other on a plane that intersects the plasma irradiation direction. While performing the relative movement, the workpiece is irradiated with plasma to give a predetermined treatment.

  Therefore, by using the plasma generator that monitors the plasma output characteristics and performs feedback control based on the measurement result, a workpiece processing apparatus that can stably and efficiently process the workpiece is realized. Can do.

  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 generation unit PU (plasma generation apparatus) that generates plasma and irradiates the workpiece W, which is an object to be processed, 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 which conveys. 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 normal temperature and pressure using microwaves. In general, the waveguide 10 propagates microwaves, and one end side of the waveguide 10 ( Microwave generator 20 arranged on the left side to generate microwaves of a predetermined wavelength, plasma generator 30 provided on waveguide 10, and arranged on the other end side (right side) of waveguide 10 to reflect microwaves The sliding short 40 to be performed, the circulator 50 for separating the reflected microwaves from the microwaves emitted to the waveguide 10 so as not to return to the microwave generator 20, and the dummy load 60 for absorbing the reflected microwaves separated by the circulator 50. In addition, a stub tuner 70 for matching impedance between the waveguide 10 and the plasma generation nozzle 31 is provided. The conveying means C includes a conveying roller 80 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 sliding short 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 being conveyed by the conveying roller 80. 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 (internal conductor), a nozzle body 33 (external 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-like member having a diameter of about 1 to 5 mm. The upper end 321 side of the center conductor 32 is a lower plate 13B of the third waveguide piece 13. While vertically penetrating and projecting into the waveguide space 130 by a predetermined length (this projecting portion is referred to as a receiving antenna unit 320), the lower end 322 is substantially flush with the lower end edge 331 of the nozzle body 33. 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 sliding short 40 is provided for optimizing the coupling state between the central conductor 32 provided in each plasma generation nozzle 31 and the microwave propagated inside the waveguide 10. The third wave guide piece 13 is connected to the right end of the third waveguide piece 13 so that the standing wave pattern can be adjusted by changing the microwave reflection position. Therefore, when a standing wave is not used, a dummy load having a radio wave absorption function is attached instead of the sliding short 40.

  FIG. 7 is a perspective view showing the internal structure of the sliding short 40. As shown in FIG. 7, the sliding short 40 includes a housing structure having a rectangular cross section similar to that of the waveguide 10, and a housing portion 41 having a hollow space 410 made of the same material as the waveguide 10. A cylindrical reflecting block 42 housed in the hollow space 410, a rectangular block 43 that is integrally attached to the base end of the reflecting block 42 and slides in the left-right direction in the hollow space 410, and A moving mechanism 44 assembled to the rectangular block 43 and an adjusting knob 46 directly connected to the reflecting block 42 via a shaft 45 are provided.

  The reflection block 42 is a cylindrical body that extends in the left-right direction so that a tip surface 421 serving as a microwave reflection surface faces the waveguide space 130 of the third waveguide piece 13. The reflection block 42 may have a prismatic shape similar to that of the rectangular block 43. The moving mechanism 44 is a mechanism for propelling or retreating the rectangular block 43 and the reflecting block 42 integrated with the rectangular block 43 in the left-right direction by rotating the adjusting knob 46. 42 is movable in the left-right direction while being guided by the rectangular block 43 in the hollow space 410. The standing wave pattern is optimized by adjusting the position of the tip surface 421 by the movement of the reflection block 42. It is desirable to automate the rotation operation of the adjusting knob 46 using a stepping motor or the like.

  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.

  FIG. 8 is a top view of the plasma generation unit PU for explaining the operation of the circulator 50. As shown, the first port 51 of the circulator 50 has a first waveguide piece 11, the second port 52 has a second waveguide piece 12, and the third port 53 has a dummy load 60. It is connected. Then, the microwave generated from the microwave transmission antenna 22 of the microwave generator 20 travels from the first port 51 to the second waveguide piece 12 via the second port 52 as indicated by an arrow a. On the other hand, the reflected microwave incident from the second waveguide piece 12 side is deflected from the second port 52 toward the third port 53 and incident on the dummy load 60 as indicated by the arrow b. .

  The dummy load 60 is a water-cooled (or air-cooled) radio wave absorber that absorbs the reflected microwave and converts it into heat. The dummy load 60 is provided with a cooling water circulation port 61 for circulating cooling water therein so that heat generated by heat conversion of the reflected microwaves is exchanged with the cooling water. It has become.

  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. FIG. 9 is a perspective side view showing an installation state of the stub tuner 70. As shown in the figure, the three stub tuner units 70 </ b> A to 70 </ b> C have the same structure, a stub 71 protruding into the waveguide space 120 of the second waveguide piece 12, and an operation rod 72 directly connected to the stub 71. And a moving mechanism 73 for moving the stub 71 up and down in the vertical direction, and an outer jacket 74 for holding these mechanisms.

  In the stub 71 provided in each of the stub tuner units 70 </ b> A to 70 </ b> C, the protruding length into the waveguide space 120 can be adjusted independently by each operation rod 72. The protruding lengths of the stubs 71 are determined by searching for a point where the power consumption by the central conductor 32 is maximized (a point where the reflected microwave is minimized) while monitoring the microwave power. Such impedance matching is executed in conjunction with the sliding short 40 as necessary. The operation of the stub tuner 70 is preferably automated using a stepping motor or the like.

  The conveyance means C includes a plurality of conveyance rollers 80 arranged along a predetermined conveyance path, and the conveyance roller 80 is driven by a driving means (not shown), 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.

  Next, an electrical configuration of the work processing apparatus S according to the present embodiment will be described. FIG. 10 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 its peripheral circuits, and the like. The overall control unit 90 as a control means, a microwave output control unit 91 including an output interface, a drive circuit, and the like, a gas flow rate control. Unit 92, a conveyance control unit 93, a display unit, an operation panel, and the like, an operation unit 95 for supplying a predetermined operation signal to the overall control unit 90, and a sensor including an input interface, an analog / digital converter, and the like An input unit 96, 97, sensors 961, 971, a drive motor 931, and a flow control valve 923 are provided.

  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 generating nozzle 31 is adjusted.

  The conveyance control unit 93 controls the operation of the drive motor 931 that rotationally drives the conveyance roller 80, and controls the start / stop of conveyance of the workpiece W, the conveyance speed, and the like.

  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 is monitored, and the microwave output control unit 91, the gas flow rate control unit 92, and the conveyance control unit 93 are controlled based on a predetermined sequence. Control the operation.

  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. Thereby, a plurality of works W are processed continuously.

  At this time, the CPU 901 as the control means is provided for each of the plurality of plasma generation nozzles 31 and monitors the measurement result of the flow rate sensor 961 as the measurement means. In the memory 903 as the storage means, the manufacturer Based on the control program stored in the memory 902 so as to read out the plasma output characteristics such as the plume size and shape corresponding to the flow rate measured and stored in advance, and the temperature of the plasma. Then, the opening degree of the flow control valve 923 is adjusted. For example, the flow rate is increased when the plume P is increased, and the flow rate is decreased when the plasma temperature is increased. Further, when the height is different due to electronic parts being mounted on the workpiece W, the height of the plume P from each plasma generating nozzle 31 can be changed.

  Furthermore, the CPU 901 causes the flow rate of the gas supplied to all the plasma generation nozzles to exceed the predetermined value by the flow rate sensors 961, and the gas supply from the processing gas supply source 921 is normally performed. If it is measured, the microwave output control unit 91 generates microwaves, and the flow rate of the gas supplied to at least one plasma generation nozzle is equal to or lower than a predetermined value. When it is measured that the supply of gas from the gas supply source 921 is stopped, the microwave output control unit 91 performs an interlock operation for stopping the generation of microwaves.

  FIG. 11 is a cross-sectional view showing an example of the configuration of the flow sensor 961. The flow sensor 961 of this example protrudes into the gas supply pipe 922 and has a baffle plate (hinge) 9611 having a predetermined area with respect to the cross section of the flow path, and the baffle plate 9611 so as to be perpendicular to the flow path direction. A sensor main body 9612 that biases and outputs a voltage corresponding to an inclination angle by the gas flow is configured. The CPU 901 can detect the flow rate of the processing gas from the output voltage of the sensor body 9612.

Note that the output voltage of the sensor main body 9612 can be used as it is for control even if the actual flow rate of how many cm ³ / sec is not required. For example, the actual numerical value can be converted by displaying the flow rate on the operation unit 95 or the like. If necessary, a conversion table of the output voltage of the sensor main body 9612 and the flow rate corresponding to the output voltage may be stored in the memory 903 and read out. It goes without saying that other configurations may be used for the flow rate sensor 961, such as a heat source and a temperature sensor that form a pair are arranged in the gas supply pipe 922, and the flow rate is obtained from a temperature drop due to cooling of the gas flow.

  If there are a plurality of types of plasma generating nozzles 31, the memory 903 stores the plasma output characteristics corresponding to the types. In addition, the parameters for obtaining the plasma output characteristics are not limited to the flow rate, and other characteristics such as the flow rate, type, and mixing ratio of the processing gas may be used. When used in any combination, a table of plasma output characteristics corresponding to each parameter or the combination is stored in the memory 903. Furthermore, the CPU 901 may perform feedback control of the microwave output control unit 91 based on the characteristics of the processing gas, and may perform feedback control of the microwave output control unit 91 and the flow rate control valve 923 together. May be.

  FIG. 12 is a flowchart for explaining the operation of adjusting the plasma output characteristics as described above by the CPU 901. In step S1, the flow rate control valve 923 is opened until the flow rate of the processing gas detected by the flow rate sensor 961 reaches a predetermined flow rate, and in step S2, the processing gas is supplied to all the plasma generating nozzles to be lit. If there is a nozzle that is not supplied, an error is displayed on the display means of the operation unit 95 in step S3, the process is terminated, and the plasma generating nozzle to be lit by plasma is terminated. When all the processing gases are supplied, in step S4, microwaves are generated from the microwave generation unit 20 via the microwave output control unit 91, and plasma ignition is performed.

  In step S5, the flow rate of the gas supplied to all plasma generating nozzles to be plasma-lit is measured by the flow rate sensors 961, and the measurement result is stored in the memory 903 in step S6. In step S7, it is determined whether or not the desired characteristics are obtained. If the desired characteristics are not obtained, it is further determined in step S8 whether any of the plasma generation nozzles has stopped supplying gas. If any one of them is stopped, generation of microwaves is performed in step S9. An interlock operation for stopping is performed, and display is performed on the display means of the operation unit 95 in step S3.

  On the other hand, when the gas supply is not stopped in step S8, the opening of the flow control valve 923 is adjusted in step S10, and then the process proceeds to step S11, and the desired characteristics are obtained in step S7. If it is, the process proceeds directly to step S11. In step S11, it is determined whether or not the operation is finished. If not finished, the process returns to step S5, and if finished, the process is finished.

  According to the workpiece processing apparatus S described above, the workpiece W is transported by the workpiece transport means C, and the plasmaized gas from the plasma generating nozzles 31 arranged and attached to the waveguide 10 is supplied to the workpiece W. Since it can radiate | emit with respect to a workpiece | work, a plasma processing can be continuously performed with respect to several to-be-processed workpiece | work, and a plasma processing can be efficiently performed also about the workpiece | work of a large area. Therefore, it is possible to provide the work processing apparatus S or the plasma generation apparatus PU that is superior in plasma processing workability to various types of workpieces as compared with batch processing type work processing apparatuses. Moreover, since plasma can be generated at an external temperature and pressure, a vacuum chamber or the like is not required, and the equipment configuration can be simplified.

  Further, the microwave generated from the microwave generator 20 is received by the central conductor 32 provided in each plasma generation nozzle 31, and the gas generated from each plasma generation nozzle 31 based on the energy of the microwave is converted into plasma. Therefore, the transmission system of the energy held by the microwave to each plasma generating nozzle 31 can be simplified. Therefore, simplification of the device configuration, cost reduction, and the like can be achieved.

  Further, since the plasma generation unit 30 in which the plurality of plasma generation nozzles 31 are arranged in a line has a width that substantially matches the size t in the width direction orthogonal to the conveyance direction of the flat workpiece W, By simply passing the workpiece W through the plasma generating unit 30 only once by the conveying means C, the processing of the entire surface can be completed, and the plasma processing efficiency for the plate-shaped workpiece can be remarkably improved. In addition, plasmaized gas can be radiated to the workpiece W being conveyed at the same timing, and uniform surface treatment or the like can be performed.

  Furthermore, since the overall control unit 90 monitors the flow rate of the processing gas to each plasma generating nozzle 31 and feedback-controls the flow rate so that the plasma output characteristic obtained from each flow rate becomes a desired characteristic. A stable plume can be obtained with each of the plasma generating nozzles 31 and plasma processing can be performed uniformly and efficiently on the plurality of workpieces and workpieces having a large area. Further, when the flow rate of the gas supplied to at least one plasma generation nozzle becomes a predetermined value or less, an interlock operation for stopping the microwave output control unit 91 is performed, so that the central conductor 32 of the plasma generation nozzle 31 is abnormal. Can be prevented from becoming too hot and burning.

The work processing apparatus S according to the embodiment of the present invention has been described above, but the present invention is not limited to this, and for example, the following embodiment can be taken.
(1) In the above embodiment, an example in which a plurality of plasma generating nozzles 31 are arranged in a line is shown. However, the nozzle arrangement may be appropriately determined according to the shape of the workpiece W, the power of microwave power, and the like. The plurality of rows of plasma generating nozzles 31 may be arranged in a matrix or in a staggered arrangement in the conveyance direction of the workpiece W.
(2) In the above-described embodiment, the transport unit C that transports the workpiece W is used as the moving unit. As the transport unit C, a mode in which the workpiece W is mounted on the upper surface of the transport roller 80 and transported is exemplified. In addition to this, for example, a form in which the work W is nipped between the upper and lower transport rollers and transported, a form in which the work is stored in a predetermined basket or the like without using the transport roller, and the basket or the like is transported by a line conveyor or the like, or a robot hand For example, the workpiece W may be gripped and conveyed to the plasma generation unit 30 by using a method such as that described above. Alternatively, the moving means may be configured to move the plasma generating nozzle 31 side. That is, the workpiece W and the plasma generation nozzle 31 may be relatively moved on a plane (X, Y plane) intersecting with the plasma irradiation direction (Z direction).
(3) In the above embodiment, a magnetron that generates a microwave of 2.45 GHz is illustrated as a microwave generation source. However, various high-frequency power sources other than the magnetron can be used, and a microwave having a wavelength different from 2.45 GHz. A wave may be used.
(4) In order to measure the microwave power in the waveguide 10, it is desirable to install a power meter at an appropriate position of the waveguide 10. For example, in order to know the ratio of the reflected microwave power to the microwave power emitted from the microwave transmission antenna 22 of the microwave generator 20, a power meter is provided between the circulator 50 and the second waveguide piece 12. Can be interposed.
(5) In the above embodiment, a hinge switch having a baffle plate (hinge) 9611 and a sensor main body 9612 is used as the flow rate sensor 961, but the rotation is applied to the windmill whose rotational speed changes according to the flow rate. A combination of sensors to be detected and a magnet that is displaced according to the flow rate can be used in combination with a Hall element that detects the displacement, etc., taking into account the required measurement accuracy and sensor cost, What is necessary is just to select suitably.

  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 see-through | perspective perspective view which shows the internal structure of a sliding short. It is a top view of the plasma generation unit for demonstrating the effect | action of a circulator. It is a see-through | perspective side view which shows the installation condition of a stub tuner. It is a block diagram which shows the control system of a workpiece processing apparatus. It is sectional drawing which shows one structural example of a flow sensor. It is a flowchart for demonstrating the adjustment operation of the plasma output characteristic by CPU.

Explanation of symbols

10 Waveguide 20 Microwave generator (microwave generator)
30 Plasma generator 31 Plasma generator nozzle 32 Central conductor (internal conductor)
33 Nozzle body (external conductor)
34 Nozzle holder 344 Gas supply hole (gas supply part)
40 Sliding short 50 Circulator 60 Dummy load 70 Stub tuner 80 Conveying roller 90 Overall control unit 901 CPU
902, 903 Memory 91 Microwave output control unit 92 Gas flow rate control unit 921 Process gas supply source 922 Gas supply pipe 923 Flow control valve 93 Transfer control unit 931 Drive motor 95 Operation unit 96, 97 Sensor input unit 961 Flow rate sensor 9611 Baffle plate 9612 Sensor body 971 Speed sensor S Work processing unit PU Plasma generation unit (plasma generator)
C Conveying means W Workpiece

Claims (5)

A microwave generating means for generating a microwave; a waveguide for propagating the microwave; and a plasma generating nozzle for receiving and generating a plasma gas based on the energy of the microwave. In a plasma generator configured to include a plasma generator attached to a waveguide,
A plurality of the plasma generating nozzles are arranged and attached to the waveguide,
Measuring means for measuring the characteristics of the gas supplied from the gas supply source to each plasma generating nozzle;
Storage means for storing in advance plasma output characteristics corresponding to the characteristics of each gas in each plasma generating nozzle;
Control means for reading out the plasma output characteristic corresponding to the measurement result of the measurement means from the storage means and controlling at least one of the microwave generation means and the gas supply source based on the read result. A plasma generating apparatus.   The characteristic of the gas is a flow rate of the gas, and when the control unit measures that the flow rate of the gas supplied to the at least one plasma generation nozzle is a predetermined value or less by the measurement unit, 2. The plasma generating apparatus according to claim 1, wherein the microwave generating means is stopped.   3. The plasma generating apparatus according to claim 1, wherein the gas characteristic is at least one of a gas flow rate, a flow velocity, a kind, and a mixing ratio.   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. In the plasma generation method in which the microwave generated by the microwave generation means propagates through the waveguide, the microwave is received by the plasma generation nozzle, and the plasmaized gas is generated and released.
A plurality of the plasma generation nozzles are arranged and attached to the waveguide of the plasma generation unit,
The plasma output characteristics corresponding to the characteristics of each gas in each plasma generating nozzle are stored in advance,
Measure the characteristics of the gas supplied from the gas supply source to each plasma generation nozzle,
A plasma generation method characterized in that the plasma output characteristics of each plasma generation nozzle are monitored by reading out the plasma output characteristics corresponding to the measurement result.

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