JP2014093223A - Plasma processing apparatus and high frequency generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing apparatus with which productivity can be improved.SOLUTION: The plasma processing apparatus is configured to process an object to be processed using plasma, and includes a processing container in which the processing by the plasma is carried out and a plasma generating mechanism which includes a microwave generator (41a) arranged outside the processing container and generating a microwave, and generates the plasma in the processing container using the microwave generated by the microwave generator (41a). The microwave generator (41a) includes a first magnetron (42a) which oscillates a microwave, a second magnetron (42b) provided separately from the first magnetron (42a) and oscillating a microwave, a waveguide (61) propagating the microwave oscillated by the first or second magnetron (42a) or (42b) to the processing container side as a load side, and a switching mechanism switching an oscillation source for the microwave to be propagated to the processing container side from the first magnetron (42a) to the second magnetron (42b).

Description

  The present invention relates to a plasma processing apparatus and a high-frequency generator, and more particularly to a high-frequency generator that generates microwaves and a plasma processing apparatus that generates plasma using microwaves.

  Semiconductor elements such as LSI (Large Scale Integrated Circuits) and MOS (Metal Oxide Semiconductor) transistors, liquid crystal displays (LCDs), organic EL (Electro Luminescence) elements and processing targets, etc. It is manufactured by performing processes such as etching, CVD (Chemical Vapor Deposition), and sputtering. As for processing such as etching, CVD, and sputtering, there are processing methods using plasma as its energy supply source, that is, plasma etching, plasma CVD, plasma sputtering, and the like.

  Here, the technique regarding the plasma processing apparatus which processes using a plasma is disclosed by WO2004 / 068917 (patent document 1). According to Patent Document 1, it is disclosed that a magnetron is used as a high-frequency oscillation source when generating a microwave. A magnetron can be configured at a relatively low cost and can output high power, so that it is effectively used as an oscillation source for generating microwaves.

WO2004 / 068917

  As a high-frequency oscillation source, there is a case where an apparatus composed of a machined product is used. For example, a case where a magnetron is used as shown in Patent Document 1 described above will be described. The magnetron is composed of a machined product such as a filament, an anode vane that constitutes the anode side, a cavity resonance portion, or the like. About the magnetron manufactured by assembling such a machined product, the state of the magnetron changes as it is used as compared with the so-called initial state immediately after assembly. For example, there is a change in the oscillation state caused by the consumption of the surface carbide layer of the thorium tungsten alloy that is a material constituting the filament. When the change in the state of the magnetron is large, there is a possibility of affecting the plasma processing, so that it becomes necessary to replace so-called consumables such as filaments or to replace the magnetron itself. That is, since the magnetron has a so-called lifetime, it must be replaced at a certain timing such as when the lifetime is reached after the start of use.

  Here, if the magnetron reaches the replacement timing, the magnetron is replaced. However, the operation of the plasma processing apparatus must be stopped during the replacement of the magnetron. Of course, during this time, plasma treatment cannot be performed, resulting in production downtime. From the viewpoint of improving production efficiency, such a time is preferably as short as possible.

  In particular, when performing many plasma processes in parallel using a large number of plasma processing apparatuses, if the timing of magnetron replacement in multiple plasma processing apparatuses overlaps, the personnel required for replacement cannot be secured and downtime is long. There is a risk of becoming.

  In one aspect of the present invention, a plasma processing apparatus is a plasma processing apparatus that performs processing on an object to be processed using plasma, and that is disposed outside a processing container that performs processing using plasma inside the plasma processing apparatus. And a plasma generation mechanism for generating plasma in the processing container using the high frequency generated by the high frequency generator. The high-frequency generator is provided separately from the first high-frequency oscillator that oscillates the high frequency and the first high-frequency oscillator, and is oscillated by the second high-frequency oscillator that oscillates the high frequency and the first or second high-frequency oscillator. A waveguide for propagating the high frequency to the processing container side, which is the load side, and a switching mechanism for switching a high frequency oscillation source for propagating to the processing container side from the first high frequency oscillator to the second high frequency oscillator.

  With this configuration, even if the first high-frequency oscillator is unable to oscillate a desired high frequency due to wear of parts due to long-term use, the high-frequency oscillation source is switched to the first high-frequency oscillator by the switching mechanism. The high frequency oscillator can be switched to a second high frequency oscillator provided separately from the first high frequency oscillator, and a desired high frequency can be oscillated by the second high frequency oscillator. Then, the period during which a desired high frequency cannot be oscillated in the high frequency generator can be shortened, and downtime can be reduced. Therefore, in the plasma processing apparatus, the period during which plasma processing cannot be performed can be shortened to improve productivity.

  In the first high-frequency oscillator, there is a case where a so-called initial failure occurs due to a component assembly failure or the like, and an appropriate high-frequency oscillation may not be performed from the beginning of operation. When plasma processing is performed using such a first high-frequency oscillator, there is a possibility that plasma cannot be generated appropriately from the initial stage of operation of the plasma processing apparatus. Even in such a situation, the first high-frequency oscillator and the second high-frequency oscillator can be switched to respond immediately. That is, it is possible to appropriately oscillate the high frequency by switching to the second high frequency oscillator in the initial stage of operation. Further, when the plasma cannot be properly generated using the first high-frequency oscillator, it is possible to easily determine whether or not the cause of the failure to generate the plasma is the high-frequency oscillator.

  The switching mechanism is provided in the waveguide, and switches the path in the waveguide to switch the high-frequency oscillation source to be propagated to the processing container side from the first high-frequency oscillator to the second high-frequency oscillator. You may comprise so that a switching device may be included.

  The switching mechanism includes a reversible circulator that is provided in the waveguide and switches the high-frequency oscillation source that propagates to the processing container side from the first high-frequency oscillator to the second high-frequency oscillator by changing the direction of the magnetic field. You may comprise.

  Further, a determination mechanism for determining the state of the first high-frequency oscillator may be provided, and the switching mechanism may be configured to switch from the first high-frequency oscillator to the second high-frequency oscillator according to the determination result by the determination mechanism.

  Moreover, you may comprise so that the notification mechanism which alert | reports to the effect of switching may be provided in the case of switching by a switching mechanism.

  The high frequency generator may include a cooling mechanism capable of cooling the first and second high frequency oscillators.

  In another aspect of the present invention, the high-frequency generator includes a first high-frequency oscillator that oscillates a high frequency, a second high-frequency oscillator that is provided separately from the first high-frequency oscillator and oscillates a high frequency, and the first or Switching from the first high-frequency oscillator to the second high-frequency oscillator, the waveguide that propagates the high-frequency wave oscillated by the second high-frequency oscillator to the processing container side that is the load side, and the high-frequency oscillation source that propagates to the processing container side Switching mechanism.

  According to such a high frequency generator, even if the first high frequency oscillator cannot oscillate a desired high frequency due to wear of parts due to long-term use, the high frequency oscillation source is switched by the switching mechanism. By switching from one high frequency oscillator to a second high frequency oscillator provided separately from the first high frequency oscillator, a desired high frequency can be oscillated by the second high frequency oscillator. Then, the period during which a desired high frequency cannot be oscillated in the high frequency generator can be shortened, and downtime can be reduced.

  According to such a configuration, even if a situation in which the desired high frequency cannot be oscillated due to wear of parts due to long-term use occurs in the first high frequency oscillator, the high frequency oscillation source is switched to the first high frequency oscillator by the switching mechanism. By switching from the high frequency oscillator to a second high frequency oscillator provided separately from the first high frequency oscillator, a desired high frequency can be oscillated by the second high frequency oscillator. Then, the period during which a desired high frequency cannot be oscillated in the high frequency generator can be shortened, and downtime can be reduced. Therefore, in the plasma processing apparatus, the period during which plasma processing cannot be performed can be shortened to improve productivity.

It is a schematic sectional drawing which shows the principal part of the plasma processing apparatus which concerns on one Embodiment of this invention. It is the schematic which looked at the slot antenna board contained in the plasma processing apparatus shown in FIG. 1 from the direction of arrow II in FIG. It is a schematic diagram which shows the periphery structure of 4E tuner as a matching apparatus contained in a microwave generator. FIG. 2 is a schematic diagram showing a configuration around an oscillation unit included in a microwave generator that oscillates high-frequency microwaves, and a filament voltage from a filament power source and a power from a high-voltage power source are supplied to the first magnetron side. Shows the case. FIG. 3 is a schematic diagram showing a configuration around an oscillation unit included in a microwave generator that oscillates microwaves having a high frequency, and a filament voltage from a filament power source and a power from a high voltage power source are supplied to the second magnetron side. Shows the case. The case where the path | route of a 1st magnetron and a waveguide is connected in a waveguide switching device is shown. The case where the path | route of the 2nd magnetron and a waveguide is connected in a waveguide switching device is shown. It is a figure which shows the structure of a cooling mechanism schematically. It is a flowchart which shows a typical process among the procedures of the process in a plasma processing apparatus. It is the schematic which shows the cooling mechanism contained in the microwave generator with which the plasma processing apparatus which concerns on other embodiment of this invention is equipped. It is the schematic which shows the cooling mechanism contained in the microwave generator with which the plasma processing apparatus which concerns on further another embodiment of this invention is equipped. It is the schematic which shows the waveguide switching device contained in the microwave generator with which the plasma processing apparatus concerning other embodiment of this invention is equipped. It is the schematic which shows the waveguide switching device contained in the microwave generator with which the plasma processing apparatus concerning other embodiment of this invention is equipped. It is the schematic which shows the structure of the periphery of the oscillation part which is contained in the microwave generator with which the plasma processing apparatus which concerns on further another embodiment of this invention is equipped, and oscillates a microwave. It is the schematic which shows the reversible circulator contained in the microwave generator shown in FIG. It is the schematic which shows the reversible circulator contained in the microwave generator shown in FIG. It is the schematic which shows the structure of the electromagnet circuit which controls operation | movement of a reversible circulator. It is a figure which shows the propagation direction of a microwave among the reversible circulators shown in FIGS. It is a figure which shows the propagation direction of a microwave among the reversible circulators shown in FIGS. It is a graph which shows the relationship between the difference of the level of the spectrum of a fundamental wave, and the level of the spectrum of a different frequency, and reflected wave electric power.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a main part of a plasma processing apparatus according to an embodiment of the present invention. 2 is a view of the slot antenna plate included in the plasma processing apparatus shown in FIG. 1 as viewed from the lower side, that is, from the direction of arrow II in FIG. In FIG. 1, some of the members are not hatched for easy understanding. In this embodiment, the vertical direction in FIG. 1 indicated by the direction indicated by arrow II in FIG. 1 or the opposite direction is the vertical direction in the plasma processing apparatus.

  Referring to FIGS. 1 and 2, the plasma processing apparatus 11 performs processing on a target substrate W, which is a target to be processed, using plasma. Specifically, processes such as etching, CVD, and sputtering are performed. As the substrate to be processed W, for example, a silicon substrate used for manufacturing a semiconductor element can be cited.

  The plasma processing apparatus 11 includes a processing container 12 that performs processing on the target substrate W with plasma therein, and a gas supply unit 13 that supplies a gas for plasma excitation and a gas for plasma processing into the processing container 12. A disk-shaped holding table 14 provided in the processing container 12 and holding the substrate W to be processed thereon, a plasma generating mechanism 19 for generating plasma in the processing container 12 using microwaves, and plasma processing And a control unit 15 that controls the operation of the entire apparatus 11. The control unit 15 controls the entire plasma processing apparatus 11 such as the gas flow rate in the gas supply unit 13 and the pressure in the processing container 12.

  The processing container 12 includes a bottom portion 21 located on the lower side of the holding table 14 and a side wall 22 extending upward from the outer periphery of the bottom portion 21. The side wall 22 is substantially cylindrical. An exhaust hole 23 for exhaust is provided in the bottom portion 21 of the processing container 12 so as to penetrate a part thereof. The upper side of the processing container 12 is open, and a lid 24 disposed on the upper side of the processing container 12, a dielectric window 16 described later, and a seal member interposed between the dielectric window 16 and the lid 24. The processing container 12 is configured to be hermetically sealed by the O-ring 25.

  The gas supply unit 13 includes a first gas supply unit 26 that blows gas toward the center of the substrate to be processed W, and a second gas supply unit 27 that blows gas from the outside of the substrate to be processed W. The gas supply hole 30 a that supplies gas in the first gas supply unit 26 is more dielectric than the lower surface 28 of the dielectric window 16 that is the center in the radial direction of the dielectric window 16 and that faces the holding table 14. It is provided at a position retracted inward of the body window 16. The first gas supply unit 26 supplies an inert gas for plasma excitation and a gas for plasma processing while adjusting a flow rate and the like by a gas supply system 29 connected to the first gas supply unit 26. The second gas supply unit 27 is provided with a plurality of gas supply holes 30 b for supplying an inert gas for plasma excitation and a gas for plasma processing in the processing container 12 in a part of the upper side of the side wall 22. Is formed. The plurality of gas supply holes 30b are provided at equal intervals in the circumferential direction. The first gas supply unit 26 and the second gas supply unit 27 are supplied with the same type of inert gas for plasma excitation and gas for plasma processing from the same gas supply source. In addition, according to a request | requirement, control content, etc., another gas can also be supplied from the 1st gas supply part 26 and the 2nd gas supply part 27, and those flow ratios etc. can also be adjusted.

  A high frequency power supply 38 for RF (radio frequency) bias is electrically connected to the electrode in the holding table 14 through the matching unit 39. For example, the high frequency power supply 38 can output a high frequency of 13.56 MHz with a predetermined power (bias power). The matching unit 39 accommodates a matching unit for matching between the impedance on the high-frequency power source 38 side and the impedance on the load side such as an electrode, plasma, and the processing container 12. A blocking capacitor for self-bias generation is included. During the plasma processing, the supply of the bias voltage to the holding table 14 may or may not be performed as necessary.

  The holding table 14 can hold the substrate W to be processed thereon by an electrostatic chuck (not shown). The holding table 14 includes a heater (not shown) for heating and the like, and can be set to a desired temperature by a temperature adjustment mechanism 33 provided inside the holding table 14. The holding base 14 is supported by an insulating cylindrical support portion 31 that extends vertically upward from the lower side of the bottom portion 21. The exhaust hole 23 described above is provided so as to penetrate a part of the bottom portion 21 of the processing container 12 along the outer periphery of the cylindrical support portion 31. An exhaust device (not shown) is connected to the lower side of the annular exhaust hole 23 via an exhaust pipe (not shown). The exhaust device has a vacuum pump such as a turbo molecular pump. The inside of the processing container 12 can be depressurized to a predetermined pressure by the exhaust device.

  The plasma generation mechanism 19 is provided outside the processing container 12 and includes a microwave generator 41a that generates microwaves for plasma excitation. In addition, the plasma generation mechanism 19 includes a dielectric window 16 that is disposed at a position facing the holding table 14 and introduces the microwave generated by the microwave generator 41 a into the processing container 12. The plasma generation mechanism 19 includes a slot antenna plate 17 provided with a plurality of slot holes 20 and disposed above the dielectric window 16 and radiating microwaves to the dielectric window 16. The plasma generation mechanism 19 includes a dielectric member 18 that is disposed above the slot antenna plate 17 and that propagates a microwave introduced by a coaxial waveguide 36 described later in the radial direction.

  The microwave generator 41 a is connected to the upper part of the coaxial waveguide 36 that introduces microwaves via the mode converter 34 and the waveguide 35. For example, the TE mode microwave generated by the microwave generator 41 a passes through the waveguide 35, is converted to the TEM mode by the mode converter 34, and propagates through the coaxial waveguide 36. The detailed configuration of the microwave generator 41a will be described later. The waveguide 35 side with respect to the microwave generator 41a is a load side described later.

  The dielectric window 16 has a substantially disk shape and is made of a dielectric. A part of the lower surface 28 of the dielectric window 16 is provided with an annular recess 37 that is recessed in a tapered shape for facilitating the generation of a standing wave by the introduced microwave. Due to the recess 37, plasma by microwaves can be efficiently generated on the lower side of the dielectric window 16. Specific examples of the material of the dielectric window 16 include quartz and alumina.

  The slot antenna plate 17 has a thin plate shape and a disc shape. As shown in FIG. 2, the plurality of slot holes 20 are provided so that two slot holes 20 form a pair so as to be orthogonal to each other with a predetermined interval therebetween. It is provided at a predetermined interval in the circumferential direction. Also in the radial direction, a plurality of pairs of slot holes 20 are provided at predetermined intervals.

  The microwave generated by the microwave generator 41 a is propagated to the dielectric member 18 through the coaxial waveguide 36. The inside of the dielectric member 18 sandwiched between the cooling jacket 32 and the slot antenna plate 17 which has a circulation path 40 for circulating a refrigerant or the like and adjusts the temperature of the dielectric member 18 or the like faces outward in the radial direction. The microwave spreads radially and is radiated to the dielectric window 16 from a plurality of slot holes 20 provided in the slot antenna plate 17. The microwave transmitted through the dielectric window 16 generates an electric field immediately below the dielectric window 16 and generates plasma in the processing container 12.

  When microwave plasma is generated in the plasma processing apparatus 11, in the region located directly below the lower surface 28 of the dielectric window 16, specifically, about several centimeters below the lower surface 28 of the dielectric window 16, A so-called plasma generation region having a relatively high electron temperature is formed. A so-called plasma diffusion region in which the plasma generated in the plasma generation region is diffused is formed in the region located below. This plasma diffusion region is a region where the electron temperature of plasma is relatively low, and plasma processing is performed in this region. Then, so-called plasma damage is not given to the substrate W to be processed at the time of plasma processing, and since the electron density of plasma is high, efficient plasma processing can be performed.

  The plasma generation mechanism 19 is provided with a dielectric window 16 that transmits a high frequency generated by a magnetron as a high frequency oscillator described later into the processing container 12 and a plurality of slot holes 20. And a radiating slot antenna plate 17. Further, the plasma generated by the plasma generating mechanism 19 is configured to be generated by a radial line slot antenna.

  Here, a specific configuration of the microwave generator 41a included in the plasma generation mechanism 19 provided in the plasma processing apparatus 11 having the above configuration will be described. FIG. 3 is a schematic diagram showing a configuration around a 4E tuner as a matching device included in the microwave generator 41a. FIG. 4 is a schematic diagram showing a configuration around an oscillation unit included in the microwave generator 41a and oscillating microwaves having a high frequency. In FIG. 4, FIG. 5 and the like described later, arrows indicated by dotted lines indicate transmission / reception of control signals.

  1 to 4, a microwave generator 41a includes an oscillation unit 55a that oscillates a high frequency, an isolator 49 connected to the oscillation unit 55a, and a 4E tuner 51 serving as a matching unit connected to the isolator 49. And a directional coupler 54 connected to the 4E tuner 51. The isolator 49 transmits the frequency signal in one direction from the oscillation unit 55a to the 4E tuner 51 side located on the load 50 side. The load 50 here is a member located on the downstream side of the so-called waveguide 35 such as the mode converter 34.

  The 4E tuner 51 includes four movable short-circuit plates (not shown) provided at intervals in the microwave traveling direction, and the movable short-circuit portions 52a, 52b, 52c, 52d, and the movable short-circuit portion 52a. It includes three probes 53a, 53b, and 53c located on the oscillation unit 55a side described later. The three probes 53a, 53b, 53c are provided at a distance of 1/8 of the fundamental frequency λ, that is, λ / 8, in the microwave traveling direction. Further, the arithmetic circuit 53d connected to the three probes 53a, 53b, and 53c calculates the position of the movable short-circuit plate of the movable short-circuit portions 52a to 52d from the voltage values of the three probes 53a to 53c and performs positioning.

  The 4E tuner 51 is provided with a directional coupler 54 on the oscillation unit 55a side with respect to the movable short-circuit unit 52a. The directional coupler 54 is a bidirectional coupler. The directional coupler 54 does not have to face the three probes 53a, 53b, and 53c. Using this directional coupler 54, the traveling wave and reflected wave power signals traveling in the waveguide 35 including the 4E tuner 51 are transmitted to the voltage control circuit 56 provided in the microwave generator 41a. A voltage control signal supplied from the high voltage power supply 43 and a voltage control signal supplied to the filament power supply are transmitted from the voltage control circuit 56 to control the voltages of the high voltage power supply 43 and the filament power supply 44. In other words, the voltage control circuit 56 properly sets the high-voltage power supply 43 and the filament power supply 44 to meet the magnetron specifications described later so that the set power becomes the same as the traveling wave power detected from the directional coupler 54. A current is supplied so as to be a voltage.

  The isolator 49 provided between the oscillating unit 55a and the 4E tuner 51 is configured, for example, by using one terminal of a circulator as a passive element as a dummy load. That is, the first terminal located on the oscillation unit 55a side is connected to the oscillation unit 55a, the second terminal located on the 4E tuner 51 side is connected to the 4E tuner 51, and the remaining third terminal is a dummy load. It is configured by connecting. By doing so, the isolator 49 can transmit the frequency signal in one direction from the oscillation unit 55a to the 4E tuner 51 located on the load 50 side.

  Next, the configuration of the oscillation unit 55a that is included in the microwave generator 41a and oscillates at a high frequency will be described. The microwave generator 41a is provided separately from the first magnetron 42a and the first magnetron 42a as a high-frequency oscillator that oscillates microwaves as a high frequency, and a high-frequency oscillator that similarly oscillates microwaves as a high frequency As a second magnetron 42b. In the case shown in FIG. 4, the first magnetron 42a and the second magnetron 42b are provided at opposing positions. Further, the microwave generator 41a is included in the high-voltage power source 43 that can supply a high voltage to either the first or second magnetron 42a, 42b, and the first magnetron 42a when oscillating a high frequency. And a filament power supply 44 for supplying power to the second cathode electrode 46b included in the second magnetron 42b when oscillating a high frequency.

  A circuit 45 is assembled between the first and second magnetrons 42 a and 42 b and the high-voltage power supply 43. An anode current is supplied from the high voltage power supply 43 side to the first or second magnetron 42a, 42b side via the circuit 45. A filament is incorporated in the circuit 45 in each of the first and second magnetrons 42a and 42b. In the first magnetron 42a, a microwave output to the outside is generated by a first cathode electrode 46a formed of a filament and a first anode electrode 47a formed by supplying an anode current from a high-voltage power supply 43. Generated. Further, in the second magnetron 42b, the micro output to the outside is provided by the second cathode electrode 46b constituted by a filament and the second anode electrode 47b formed by supplying an anode current from the high voltage power source 43. A wave is generated. The above-described filaments on the cathode side constituting the first and second cathode electrodes 46a, 46b, and the anode vanes forming the first and second anode electrodes 47a, 47b on the anode side are machined. It is a machined product manufactured by.

  The microwave generator 41a includes a switching mechanism that switches a microwave oscillation source to be propagated to the processing container 12 side from the first magnetron 42a to the second magnetron 42b. As part of the switching mechanism, the circuit 45 switches the supply destination of the filament voltage supplied from the filament power supply 44 and the supply destination of the power supplied from the high voltage power supply 43 to the first or second magnetron 42a, 42b. For this purpose, a first changeover switch 57a and a second changeover switch 57b are provided.

  Specifically, in the circuit 45, the first changeover switch 57a is connected to the terminal 58a located on the filament power supply 44 side, the terminal 58b located on the first cathode electrode 46a side, or the second cathode electrode 46b side. The terminal 58c that is positioned is switched, and either the terminal 58a and the terminal 58b or the terminal 58a and the terminal 58c are connected. In the circuit 45, for the second changeover switch 57b, a terminal 58d located on the filament power supply 44 side, a terminal 58e located on the first cathode electrode 46 side, or a terminal located on the second cathode electrode 46b side. 58f is switched, and either the terminal 58d and the terminal 58e or the terminal 58d and the terminal 58f are connected. By connecting the terminal 58a and the terminal 58b in the first changeover switch 57a and connecting the terminal 58d and the terminal 58e in the second changeover switch 57b, the filament power supply 44 to the first magnetron 42a side is obtained. Is supplied with the filament voltage and the power from the high-voltage power supply 43. On the other hand, the terminal 58a and the terminal 58c are connected in the first changeover switch 57a, and the terminal 58d and the terminal 58f are connected in the second changeover switch 57b, whereby the second magnetron 42b is connected. The filament voltage from the filament power supply 44 and the power from the high voltage power supply 43 are supplied.

  FIG. 4 shows a case where the filament voltage from the filament power supply 44 and the power from the high voltage power supply 43 are supplied to the first magnetron 42a side. FIG. 5 shows the state in which the filament voltage from the filament power supply 44 and the power from the high voltage power supply 43 are supplied to the second magnetron 42b side.

  The oscillating unit 55a is provided with a switching control circuit 59 for switching the first and second changeover switches 57a and 57b. In response to a control signal from the switching control circuit 59, the first and second change-over switches 57a and 57b switch the terminals for changing the connection state described above.

  Note that a microwave generator control circuit 60 that includes the voltage control circuit 56 described above and controls the entire microwave generator 41a is provided outside the oscillation unit 55a. The microwave generator control circuit 60 controls the electric power supplied from the high voltage power supply 43 and the filament voltage supplied from the filament power supply 44 through the voltage control circuit 56, and controls the control signal oscillated to the switching control circuit 59. I do.

  The oscillation unit 55a includes a first launcher 62a for propagating the high frequency oscillated by the first magnetron 42a to the waveguide 61 connected to the isolator 49, and a second magnetron as part of the switching mechanism. The second launcher 62b that propagates the high-frequency wave oscillated by 42b to the waveguide 61, and the waveguide that is connected to the first launcher 62a and the second launcher 62b and switches the path that propagates to the waveguide 61 side. A tube switch 63a is included. The waveguide 61 is connected to the isolator 49 on the downstream side in the so-called microwave propagation direction. That is, the end of the waveguide 61 is an outlet in the microwave propagation direction in the oscillating portion 55a.

  Here, the configuration of the waveguide switching unit 63a included in the switching mechanism will be described. 6 and 7 are schematic cross-sectional views showing a part of the waveguide switching device 63a. 6 shows a case where the path between the first magnetron 42a and the waveguide 61 is connected, and FIG. 7 shows a case where the path between the second magnetron 42b and the waveguide 61 is connected. 6 and 7 are schematic views corresponding to the case where the waveguide switch 63a is cut and viewed from above.

  Referring to FIGS. 6 and 7, the waveguide switch 63a is provided inside the outer frame body 64a and the outer frame body 64a, and is rotatable around a center 66a when viewed from above. And an internal rotor 65a. The waveguide switch 63a is a so-called rotary type. The outer frame body 64a has a substantially rectangular parallelepiped shape, and when viewed from above, the outer shape is a substantially square shape. Then, openings 67a, 67b, and 67c are provided in a part of three surfaces of the outer frame body 64a. Each of the openings 67a to 67c extends straight from the outer surface side to reach a position where the internal rotor 65a is disposed, and is a path 68a, 68b, 68c through which high frequency propagates. A first launcher 62a is connected to the opening 67a. A second launcher 62b is connected to the opening 67c. The outer shape of the inner rotor 65a is substantially circular when viewed from above. The internal rotor 65a is also provided with a path 68d penetrating from one opening 67d to the other opening 67e. The path 68d is provided so as to bend 90 ° while drawing a gentle arc.

In the state shown in FIG. 6, the position of the opening 67a and the position of the opening 67d are matched, and the position of the opening 67b and the position of the opening 67e are matched. In such a state, it is possible to propagate a high frequency from the opening 67a side to the opening 67b side through the path 68a, the path 68d, and the path 68b sequentially. Further, as shown in FIG. 7, the inner rotor 65a by 90 ° rotation in the direction indicated by arrow _{A 1} in FIG. 6, aligning the position and the opening 67d of the opening 67b, the location and the opening 67e of the opening 67c By adjusting the position, a high frequency can be propagated from the opening 67c side to the opening 67b side through the path 68c, the path 68d, and the path 68b.

  The high frequency oscillated from the first magnetron 42a side is propagated to the path 68a through the first launcher 62a and the opening 67a. The high frequency oscillated from the second magnetron 42b is propagated to the path 68c through the second launcher 62b and the opening 67c. The high frequency propagated from the path 68b is propagated to the waveguide 61 provided on the opening 67b side. The first and second launchers 62a and 62b and the waveguide switching unit 63a constitute a part of the waveguide for propagating microwaves in the oscillation unit 55a.

  The microwave generator 41a includes a determination mechanism 69 that determines the state of the first magnetron 42a. The determination mechanism 69 determines, for example, the replacement timing of the first magnetron 42a. The replacement timing of the first magnetron 42a will be described later.

  The microwave generator 41a includes a notification device 70 as a notification mechanism for notifying that switching is performed when the microwave oscillation source is switched from the first magnetron 42a to the second magnetron 42b. The notification device 70 is notified by sound such as an alarm or voice, or notification by light, vibration, or the like.

  The microwave generator 41a includes a cooling mechanism 71a that cools the first magnetron 42a and the second magnetron 42b. FIG. 8 is a diagram schematically showing the configuration of the cooling mechanism 71a. Referring to FIG. 8, cooling mechanism 71a is water-cooled, that is, cools with cooling water. The cooling mechanism 71a cools in close proximity to the pipe 72a through which cooling water flows, the four valves 73a, 73b, 73c, 73d provided in the middle of the pipe 72a, and the first and second magnetrons 42a, 42b. Two heat exchangers 74a and 74b for performing the above. The pipe 72a is branched into two systems, and cooling water can flow through the heat exchangers 74a and 74b in accordance with opening and closing of the valves 73a to 73d. During cooling, water is allowed to flow from the inlet 75a side of the pipe 72a. And according to the 1st or 2nd magnetron 42a, 42b used as cooling object, the valves 73a-73d are opened and closed, and cooling water is poured into heat exchanger 74a, 74b one by one. Cooling water is discharged from the outlet 75b side. In this way, the first and second magnetrons 42a and 42b are cooled.

  In addition, in order to make heat exchange efficient, it is necessary to transmit heat, and it is desirable that the outer wall portion of the anode electrode of the magnetron and the heat exchanger are in close contact with each other. Therefore, the first magnetron 42a is often supplied integrally with the heat exchanger 74a, and the second magnetron 42b is often supplied integrally with the heat exchanger 74b.

  The microwave generator 41a is configured as described above. The switching mechanism provided in the microwave generator 41a includes first and second changeover switches 57a and 57b, a changeover control circuit 59 for controlling the changeover, a waveguide changer 63a, and first and second launchers. 62a, 62b, etc. are included. Note that the determination mechanism 69, the alarm 70, and the cooling mechanism 71a described above are included in a part of the switching mechanism.

  Next, a processing procedure in the plasma processing apparatus 11 including such a microwave generator 41a will be described. FIG. 9 is a flowchart showing typical steps in the processing procedure in the plasma processing apparatus 11.

  With reference to FIGS. 1-9, plasma processing is started in the plasma processing apparatus 11 (FIG. 9 (A)). The plasma processing will be briefly described. After the substrate W to be processed is held on the holding table 14, the gas supply unit 13 supplies a gas for plasma excitation or a gas for plasma processing into the processing vessel 12, and plasma is generated. Then, plasma processing such as etching is performed. In this case, the first magnetron 42a is used as a high frequency in the microwave generator 41a, that is, a microwave oscillation source. Specifically, the terminal 58a and the terminal 58b are connected by the first changeover switch 57a, and the terminal 58d and the terminal 58e are connected by the second changeover switch 57b. In the waveguide switch 63a, a high frequency can be propagated from the opening 67a side to the opening 67b through the path 68a, the path 68d, and the path 68b sequentially. In the cooling mechanism 71a, the valves 73a and 73b are opened, and the valves 73c and 73d are closed. Then, in the state shown in FIG. 4, plasma is generated using the first magnetron 42 a as a microwave oscillation source, and plasma processing is performed on the substrate W to be processed.

  Thereafter, the determination mechanism 69 determines whether or not the first magnetron 42a has reached the replacement timing. Then, after the predetermined time has elapsed, the determination mechanism 69 detects that the first magnetron 42a has reached the replacement timing (FIG. 9B).

  Here, an example of the determination of the replacement timing in the determination mechanism 69 will be briefly described. The determination mechanism 69 determines the state of the first magnetron 42a based on the fundamental wave component and the different frequency component oscillated from the first magnetron 42a as a high frequency oscillator. A brief description of the different frequency components is as follows. As another frequency characteristic of the high frequency oscillated by the high-frequency oscillator, there is a so-called spurious different frequency component which is not intended in design. This different frequency component is included in the high frequency. This different frequency component tends to increase as the high frequency oscillator is used. The increase in the different frequency component causes a reflected wave in the waveguide and the matching unit through which the high frequency oscillated by the high frequency oscillator propagates. When this reflected wave is caused, the effective power of the first magnetron 42a and the impedance of the load when generating the microwave change, which is not preferable. That is, the timing at which this reflected wave begins to be generated is a measure of the replacement timing of the so-called first magnetron 42a.

  When the determination mechanism 69 determines that the replacement timing of the first magnetron 42a is reached, an alarm is generated by the alarm 70 to notify that the first magnetron 42a has reached the replacement timing (FIG. 9C )). At this time, the determination mechanism 69 notifies the control unit 15 of the plasma processing apparatus 11 that the first magnetron 42a has reached the replacement timing. And the control part 15 stops generation | occurrence | production of the microwave in the 1st magnetron 42a. Specifically, the supply of power from the high-voltage power supply 43 is stopped. Then, the control part 15 transmits the switching permission signal which permits switching the magnetron used as the oscillation source of a microwave. The microwave generator control circuit 60 receives this switching permission signal (FIG. 9D). Moreover, the control part 15 resets a parameter (FIG.9 (E)). The parameter reset means, for example, that the count value of the ON time during which the filament is operating is set to 0 with respect to the timer held in the control unit 15 in the control unit 15.

  After that, the microwave generator control circuit 60 transmits a magnetron switching signal to the switching control circuit 59 (FIG. 9F). Then, internal data is reset (FIG. 9G). The internal data reset means, for example, setting the count value of the filament on-time to 0 in the microwave generator control circuit 60.

When receiving the magnetron switching signal, the switching control circuit 59 switches the microwave oscillation source from the first magnetron 42a to the second magnetron 42b (FIG. 9 (H)). Specifically, the terminal 58a and the terminal 58c are connected by the first changeover switch 57a, and the terminal 58d and the terminal 58f are connected by the second changeover switch 57b. Further, the waveguide switch 63a, the inner rotor 65a by 90 ° rotation in the direction indicated by arrow _{A 1} in FIG. 6, aligning the position and the opening 67d of the opening 67b, the position of the opening 67c and the opening 67e Are adjusted so that a high frequency can be propagated from the opening 67e side to the opening 67b via the path 68c, the path 68d, and the path 68b. In the cooling mechanism 71a, the valves 73a and 73b are closed and the valves 73c and 73d are opened. And it is set as the state shown in FIG.

  After switching to the second magnetron 42b, plasma is generated again using the second magnetron 42b as a microwave oscillation source, and the plasma processing on the substrate W to be processed is continued (FIG. 9I). In this way, the plasma processing is performed on the substrate W to be processed.

  According to such a configuration, even if a situation occurs in the first magnetron 42a in which a desired microwave cannot be oscillated due to wear of parts due to long-term use, the microwave oscillation source is switched by the switching mechanism. By switching from one magnetron 42a to a second magnetron 42b provided separately from the first magnetron 42a, a desired microwave can be oscillated by the second magnetron 42b. Then, a period during which the desired microwave cannot be oscillated in the microwave generator 41a can be shortened, and downtime can be reduced. Therefore, in the plasma processing apparatus 11, the period during which plasma processing cannot be performed can be shortened, and productivity can be improved.

  In addition, it can respond appropriately also in the following cases. In the first magnetron 42a, a so-called initial failure may occur due to an assembly failure of components such as an anode vane or a filament, and appropriate microwave oscillation may not be performed from the beginning of operation. When plasma processing is performed using such a first magnetron 42a, there is a possibility that plasma cannot be generated appropriately from the initial stage of operation of the plasma processing apparatus 11. Even in such a situation, the first magnetron 42a and the second magnetron 42b can be switched to respond immediately. That is, it is possible to appropriately oscillate microwaves using the second magnetron 42b in the initial stage of operation. Further, when the plasma cannot be properly generated using the first magnetron 42a, it is possible to easily determine whether or not the cause of the failure to generate the plasma is the magnetron. In other words, if the plasma can be generated appropriately by switching from the first magnetron 42a to the second magnetron 42b, the cause of the failure to generate the plasma can be specified in the magnetron.

  Here, the switched first magnetron 42a is replaced during maintenance of the entire plasma processing apparatus 11. If the exchange is performed at such timing, the time loss can be greatly reduced.

  In the above embodiment, the cooling mechanism 71a is configured to include four valves as two systems, but is not limited to this, for example, as illustrated in FIG. It is good also as a structure which does not branch a pipe | tube. FIG. 10 is a schematic view showing a cooling mechanism 71b included in a microwave generator provided in a plasma processing apparatus according to another embodiment of the present invention, and corresponds to FIG. Referring to FIG. 10, the cooling mechanism 71b is close to a pipe 72b for flowing cooling water, two valves 73e and 73f provided in the middle of the pipe 72b, and the first and second magnetrons 42a and 42b, respectively. And two heat exchangers 74c and 74d for cooling. The pipe 72b is composed of one system, and cooling water can flow through the heat exchangers 74c and 74d according to the opening and closing of the valves 73e and 73f. You may comprise in this way.

  The cooling mechanism may have the following configuration. FIG. 11 is a schematic view showing a cooling mechanism 71c included in a microwave generator provided in a plasma processing apparatus according to still another embodiment of the present invention, and corresponds to FIG. 8 and FIG. Referring to FIG. 11, the cooling mechanism 71c includes a pipe 72c for flowing cooling water, three valves 73g, 73h, 73i provided in the middle of the pipe 72c, and first and second magnetrons 42a, 42b. Two heat exchangers 74e and 74f that perform cooling in close proximity are provided. The pipe 72c is branched on the upstream side of the valves 73g and 73h, and is configured to join downstream of the heat exchangers 74e and 74f and upstream of the valve 73i. According to opening and closing of the valves 73g, 73h, and 73i, cooling water can be supplied to the respective heat exchangers 74e and 74f. You may comprise in this way.

  In the above-described embodiment, the waveguide switch has a substantially rectangular parallelepiped shape, and the waveguide is switched by rotating the internal rotor by 90 °. The switch is not limited to such a configuration.

  12 and 13 are schematic views showing a waveguide switch included in a microwave generator provided in a plasma processing apparatus according to still another embodiment of the present invention. 12 and 13 correspond to FIGS. 6 and 7 described above.

  Referring to FIGS. 12 and 13, the waveguide switching device 63b is provided inside the outer frame body 64b and the outer frame body 64b, and is rotatable around a center 66b when viewed from above. And an internal rotor 65b. The outer frame body 64b has a substantially hexagonal column shape, and its outer shape is a substantially hexagonal shape when viewed from above. In addition, openings 67f, 67g, and 67h are provided in a part of three surfaces of the outer frame body 64b that are spaced from each other. Each of the openings 67f to 67h extends straight and reaches the position where the internal rotor 65b is disposed from the outer surface side, and becomes a path 68f, 68g, 68h through which high frequency propagates. The outer shape of the inner rotor 65b is substantially circular when viewed from above. The internal rotor 65b is also provided with a path 68i penetrating from one opening 67i to the other opening 67j. The path 68i is provided so as to bend by 120 ° along a gentle arc.

In the state shown in FIG. 12, the position of the opening 67f and the position of the opening 67i are matched, and the position of the opening 67h and the position of the opening 67j are matched. In such a state, it is possible to propagate a high frequency from the opening 67f side to the opening 67h side sequentially through the path 68f, the path 68i, and the path 68h. Further, as shown in FIG. 13, the inner rotor 65b by 120 ° rotation in the direction indicated by arrow _{A 2} in FIG. 10, aligning the position and the opening 67i of the opening 67h, the position and the opening 67j of the opening 67g By adjusting the position, a high frequency can be propagated from the opening 67g side to the opening 67h side via the path 68g, the path 68i, and the path 68h.

  A first launcher 62a is connected to the opening 67f. The high frequency oscillated from the first magnetron 42a is propagated to the path 68f through the first launcher 62a and the opening 67f. A second launcher 62b is connected to the opening 67g. The high frequency oscillated from the second magnetron 42b side is propagated to the path 68g through the second launcher 62b and the opening 67g. The high frequency propagated from the path 68h is propagated to the waveguide 61 provided on the opening 67h side. The first and second launchers 62a and 62b and the waveguide switching device 63b constitute a part of the waveguide in the oscillation unit. Such a configuration may be adopted.

  Of course, as the waveguide switching device, other configurations, for example, a configuration in which a larger number of openings, paths, and the like are provided, or a different rotation angle of the internal rotor may be used. A sensor for completing the positioning may be provided at each opening position of the waveguide switching device, and an interlock circuit may be provided to determine whether or not to output the microwave by oscillating the magnetron.

  In the above embodiment, the rotary waveguide switch is used. However, the present invention is not limited to this, and a waveguide switch including a reversible circulator may be used.

  FIG. 14 is a schematic diagram showing a configuration around an oscillation unit included in a microwave generator provided in a plasma processing apparatus according to still another embodiment of the present invention, which oscillates microwaves. FIG. 14 is a view corresponding to FIGS. 4 and 5 described above. In FIG. 14, members and the like having the same configurations as those in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof is omitted.

  Referring to FIG. 14, an oscillation unit 55b included in a microwave generator 41b included in a plasma processing apparatus according to still another embodiment of the present invention and oscillating microwaves is reversible as a part of a switching mechanism. An expression circulator 63c is included. The reversible circulator 63 c switches the oscillation source of the microwave propagating to the waveguide 61 from the first magnetron 42 a to the second magnetron 42 b by a switching signal from the switching control circuit 59.

  Here, the configuration of the reversible circulator 63c will be described. 15 and 16 are schematic views showing a reversible circulator 63c included in the microwave generator shown in FIG. FIG. 17 is a schematic diagram showing the configuration of an electromagnet circuit that controls the operation of the reversible circulator 63c. 18 and 19 are diagrams showing the propagation direction of the microwave in the reversible circulator 63c shown in FIGS. Reference numerals 78a and 78b in FIGS. 18 and 19 indicate the direction of the magnetic field, that is, the direction of the lines of magnetic force. The reference numeral 78a shown in FIG. 18 indicates that the magnetic field is directed from the front side to the back side of the paper, while the reference numeral 78b illustrated in FIG. 19 indicates that the magnetic field is directed from the back side to the front side of the paper.

  14 to 19, the reversible circulator 63c includes a ferrite 76 at the center thereof and includes three ports 77a, 77b, and 77c provided at intervals of 120 °. The reversible circulator 63c is controlled by an electromagnet circuit 81 in which a DC power source 82, a protective resistor 83, an electromagnet 85 including a pair of coils 84a and 84b, and a changeover switch 86 are incorporated. Specifically, a pair of coils 84 a and 84 b are arranged in the vertical direction of the ferrite 76, and by changing the energization state by the electromagnet circuit 81, the one coil 84 a goes to the other coil 84 b. The direction of the magnetic force line 87 indicated by the dotted line in FIG. 19 can be changed. Specifically, the changeover switch 86 is switched to one terminal, the coil 84a disposed on the upper side of the ferrite 76 is an N pole, and the coil 84b disposed on the lower side of the ferrite 76 is an S pole. Magnetic field lines 87 in the direction indicated by the dotted lines can be generated. Further, the changeover switch 86 is switched to the other terminal so that the coil 84a disposed on the upper side of the ferrite 76 is an S pole and the coil 84b disposed on the lower side of the ferrite 76 is an N pole. Magnetic field lines in the direction opposite to the direction shown can be generated.

  The reversible circulator 63c can change the propagation direction between the ports 77a to 77c in the circulator as a passive element by changing the direction of the magnetic force line 87. Specifically, in the state shown in FIG. 18, that is, the magnetic field line 87 is directed from the coil 84a to the coil 84b, the port 77a is directed to the port 77c, the port 77c is directed to the port 77b, and the port 77b is directed to the port 77a. Thus, the transmission direction can be one direction. On the contrary, in the state shown in FIG. 19, that is, by configuring the magnetic field lines 87 to face from the coil 84b to the coil 84a, transmission is performed from the port 77a to the port 77b, from the port 77c to the port 77a, and from the port 77b to the port 77c. The direction can be one direction.

Using the reversible circulator 63c having such a configuration, it is possible to switch the magnetron serving as a microwave oscillation source. That is, the first magnetron 42a is connected to the port 77a, the second magnetron 42b is connected to the port 77b, and the waveguide 61 is connected to the port 77c. In the electromagnet circuit 81, when the changeover switch 86 is switched so that the magnetic lines of force 87 are generated in the direction from the coil 84a to the coil 84b, microwaves are propagated as indicated by arrows A ₄ and A ₅ in FIG. The In this way, microwaves can be propagated from the first magnetron 42a to the waveguide 61 via the reversible circulator 63c. When the microwave oscillation source is switched from the first magnetron 42a to the second magnetron 42b based on the determination by the determination mechanism described above, a magnetic force line is generated in the direction from the coil 84b to the coil 84a by switching the switch 86. To do. Then, the microwave propagates as indicated by arrows A ₆ and A ₅ in FIG. In this way, microwaves can be propagated from the second magnetron 42b to the waveguide 61 via the reversible circulator 63c. You may comprise in this way.

  When such a reversible circulator is employed, the lines of magnetic force may be strengthened by placing an iron core inside the coils 84a and 84b. In addition, a magnetic sensor such as a semiconductor magnetoresistive element or a Hall element is attached, and the interlock circuit is used to detect whether the direction of magnetic lines of force and the magnitude of the lines of magnetic force can be oscillated to generate microwave output. It may be.

  As described above, according to the above configuration, the period during which plasma treatment cannot be performed can be shortened, and productivity can be improved.

  In the above-described embodiment, in the microwave generator, the determination mechanism, the notification mechanism, and the cooling mechanism are included in the oscillating unit. However, the configuration is not limited thereto, and the determination mechanism, the notification mechanism, and the cooling mechanism are not limited thereto. The mechanism may be configured to be included in, for example, a plasma processing apparatus outside the oscillation unit.

  Further, in the above embodiment, the determination mechanism may not be provided. In this case, for example, the microwave oscillation source may be switched from the first magnetron to the second magnetron at a predetermined timing regardless of the state of the first magnetron. In addition, the notification mechanism may not be provided, and the cooling mechanism is water-cooled in the above embodiment, but may be air-cooled, and may be configured without a cooling mechanism as necessary. Also good.

  In the above-described embodiment, the increase in the different frequency component in the determination mechanism is used as the replacement timing of the magnetron. As such a determination mechanism, for example, the following configuration is provided. That is, although not shown in the drawings, the determination mechanism detects the spectrum level of the fundamental wave component of the microwave and the spectrum level of the component of the different frequency, and the fundamental wave detected by the spectrum level detection unit. A spectrum level comparing unit that compares the spectrum level value of the component and the spectrum level value of the component of the different frequency. The spectrum level detection unit includes a branch unit provided in the middle of the waveguide, an attenuator that is branched from the branch unit and attenuates the input frequency signal, and a frequency signal is input from the attenuator. A band-pass filter, a second band-pass filter that receives a frequency signal from an attenuator, a first detector that detects a frequency that has passed through the first band-pass filter, and a second band-pass filter A second detector for detecting the passed frequency, a first gain adjusting amplifier for amplifying the frequency signal detected by the first detector, and a second for amplifying the frequency signal detected by the second detector. Including a gain adjustment amplifier. The spectrum level comparison unit includes a subtraction circuit that calculates a difference between the frequency amplified by the first gain adjustment amplifier and the frequency amplified by the second gain adjustment amplifier, and the difference value calculated by the subtraction circuit. And a threshold value that is a predetermined value, and a threshold value adjustment unit that adjusts the threshold value to be compared by the comparator.

  The first band-pass filter performs filtering to pass only the frequency band of the fundamental wave component and remove other frequency bands. In the first detector, the component of the fundamental wave that has passed through the first bandpass filter is detected. The fundamental wave component detected by the first detector is amplified by the first gain adjustment amplifier and input to the subtraction circuit. The second band-pass filter performs filtering to pass only the frequency band of the different frequency component and remove the other frequency bands. In the second detector, a component having a different frequency that has passed through the second bandpass filter is detected. The different frequency component detected by the second detector is amplified by the second gain adjustment amplifier and input to the subtraction circuit. The subtraction circuit calculates the difference between the spectrum level of the amplified fundamental wave and the spectrum level of the different frequency. The calculated difference is input to the comparator. In addition, a threshold value that is a comparison target of the difference adjusted by the threshold value adjustment unit is also input to the comparator. The comparator compares the difference value with the threshold value, and determines the state of the magnetron based on the comparison result. This determination result is input to the alarm and notified.

  FIG. 20 is a graph showing the relationship between the difference between the spectrum level of the fundamental wave and the spectrum level of the different frequency and the reflected wave power. The generation of this reflected wave power is undesirable. Referring to FIG. 20, if the difference in spectrum level is 40.0 dBm or more, the value of the reflected wave power is 0 (W). That is, no reflected wave power is generated. On the other hand, if the difference in spectrum level is smaller than 40.0 dBm, reflected wave power is generated. Here, if the difference in spectrum level is 40 dBm or more, it can be understood that no reflected wave power is generated. Therefore, in this embodiment, 40.0 dBm is set as the threshold value. Then, at the timing when this difference becomes smaller than 40.0 dBm, an alarm device generates an alarm sound. This timing is a measure of the replacement timing of the magnetron.

  In addition, as a determination mechanism, for example, the initial frequency of the fundamental wave and the current frequency of the fundamental wave are detected, and the detected initial frequency of the fundamental wave is compared with the current frequency of the fundamental wave. The timing may be determined. Further, the initial efficiency of the magnetron and the current efficiency of the magnetron may be detected, and the initial efficiency of the detected magnetron and the current efficiency of the magnetron may be compared to determine the replacement timing. Furthermore, the replacement timing may be determined using the accumulated usage time of the magnetron.

  The internal data to be reset includes, for example, magnetron integration usage time, filament power on / off count, filament power supply time, filament power supply time integration value, etc. Can be mentioned.

  In the above embodiment, the magnetron is used as the high-frequency oscillator. However, the present invention is not limited to this, and the present invention can be applied to the case where another high-frequency oscillator is used.

  In the above embodiment, the plasma processing is performed by the microwave using the radial line slot antenna. However, the plasma processing is not limited to this, and a comb-shaped antenna unit is provided and plasma is generated by the microwave. A plasma processing apparatus or a plasma processing apparatus that generates plasma by emitting microwaves from a slot may be used.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  DESCRIPTION OF SYMBOLS 11 Plasma processing apparatus, 12 Processing container, 13, 26, 27 Gas supply part, 14 Holding stand, 15 Control part, 16 Dielectric window, 17 Slot antenna plate, 18 Dielectric member, 19 Plasma generating mechanism, 20 Slot hole, 21 bottom part, 22 side wall, 23 exhaust hole, 24 lid part, 25 O-ring, 28 bottom surface, 29 gas supply system, 30a, 30b gas supply hole, 31 cylindrical support part, 32 cooling jacket, 33 temperature adjustment mechanism, 34 mode Converter, 35, 61 waveguide, 36 coaxial waveguide, 37 recess, 38 high frequency power supply, 39 matching unit, 40 circuit, 41a, 41b microwave generator, 42a, 42b magnetron, 43 high voltage power supply, 44 filament Power supply, 45 circuit, 46a, 46b cathode electrode, 47a, 47b anode electrode, 4 9 isolator, 50 load, 514E tuner, 52a, 52b, 52c, 52d movable short circuit, 53a, 53b, 53c probe, 53d arithmetic circuit, 54 directional coupler, 55a, 55b oscillator, 56 voltage control circuit, 57a 57b, 86 selector switch, 58a, 58b, 58c, 58d, 58e, 58f terminal, 59 switching control circuit, 60 microwave generator control circuit, 62a, 62b launcher, 63a, 63b waveguide switch, 63c reversible type Circulator, 64a, 64b outer frame, 65a, 65b inner rotor, 66a, 66b center, 67a, 67b, 67c, 67d, 67e, 67f, 67g, 67h, 67i, 67j opening, 68a, 68b, 68c, 68d, 68e 68f, 68g, 68h , 68i path, 69 judgment mechanism, 70 alarm, 71a, 71b, 71c cooling mechanism, 72a, 72b, 72c pipe, 73a, 73b, 73c, 73d, 73e, 73f, 73g, 73h, 73i valve, 74a, 74b, 74c, 74d, 74e, 74f Heat exchanger, 75a inlet, 75b outlet, 76 ferrite, 77a, 77b, 77c port, 78a, 78b code, 81 electromagnet circuit, 82 DC power supply, 83 protection resistance, 84a, 84b coil, 85 Electromagnet, 87 magnetic field lines.

Claims (7)

A plasma processing apparatus for processing an object to be processed using plasma,
A processing vessel for processing with plasma inside,
A high-frequency generator that is arranged outside the processing vessel and generates a high frequency, and includes a plasma generation mechanism that generates plasma in the processing vessel using the high-frequency generated by the high-frequency generator,
The high-frequency generator is provided separately from the first high-frequency oscillator that oscillates a high frequency, the second high-frequency oscillator that oscillates a high frequency, and the first or second high-frequency oscillator. A waveguide for propagating the oscillated high frequency to the processing vessel side serving as a load side, and a switching mechanism for switching a high frequency oscillation source for propagating to the processing vessel side from the first high frequency oscillator to the second high frequency oscillator And a plasma processing apparatus. The switching mechanism is provided in the waveguide, and switches a path in the waveguide to switch a high-frequency oscillation source that propagates to the processing container side from the first high-frequency oscillator to the second high-frequency oscillator. The plasma processing apparatus according to claim 1, comprising a waveguide switching device for switching. The switching mechanism is provided in the waveguide and is a reversible type that switches a high-frequency oscillation source that propagates to the processing container side from the first high-frequency oscillator to the second high-frequency oscillator by changing the direction of a magnetic field. The plasma processing apparatus according to claim 1, comprising a circulator. A determination mechanism for determining the state of the first high-frequency oscillator;
The plasma processing apparatus according to claim 1, wherein the switching mechanism switches from the first high-frequency oscillator to the second high-frequency oscillator in accordance with a determination result by the determination mechanism. The plasma processing apparatus according to any one of claims 1 to 4, further comprising a notification mechanism for notifying that switching is performed when switching is performed by the switching mechanism. The plasma processing apparatus according to claim 1, wherein the high-frequency generator includes a cooling mechanism capable of cooling the first and second high-frequency oscillators. A first high-frequency oscillator that oscillates a high frequency, a second high-frequency oscillator that is provided separately from the first high-frequency oscillator, and that loads the high-frequency oscillated by the first or second high-frequency oscillator A high-frequency generation comprising: a waveguide propagating toward the processing vessel as a side; and a switching mechanism for switching a high-frequency oscillation source propagating toward the processing vessel from the first high-frequency oscillator to the second high-frequency oscillator vessel.

Images