JP2015206678A - Probe and method for detecting electric field, and processor using microwave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a probe for detecting an electric field.SOLUTION: A probe 1 which has a coaxial structure includes a coaxial tube 2 and a sensor part. The coaxial tube includes a tip part 2a. The coaxial tube also includes a central conductor 4, a dielectric 5, an outer conductor 6, and an electromagnetic wave absorber 7. The dielectric covers an outer periphery of the central conductor, the outer conductor covers an outer periphery of the dielectric, and the electromagnetic wave absorber covers an outer periphery of the outer conductor. The central conductor is short-circuited by the outer conductor at the tip part of the coaxial tube. The coaxial tube has the sensor part at a position away from the tip part. In the sensor part, a slot which extends in a circumferential direction with respect to a central axis line of the coaxial tube so as to expose the dielectric is formed in the electromagnetic wave absorber and the outer conductor.

Description

  Embodiments described herein relate generally to a probe for detecting an electric field, a method for detecting an electric field, and a processing apparatus using a microwave.

  There is a need for a technique for measuring an electric field in a space where electromagnetic waves propagate. For example, in order to grasp the influence of electromagnetic wave noise around an electronic device, a technique for measuring an electric field is required. In addition, a technique for measuring an electric field in a processing container is also required in a processing apparatus that processes an object to be processed such as a semiconductor substrate accommodated in the processing container by using a microwave.

  In order to meet such a demand, various electric field detection probes have been proposed as described in Patent Documents 1 to 3 below. The probes described in these documents have a coaxial structure. Specifically, these probes have a center conductor, a dielectric covering the outer periphery of the center conductor, an outer conductor covering the outer periphery of the dielectric, and a skin covering the outer periphery of the outer conductor. The center conductor, the dielectric, and the outer conductor are exposed at the tip of the probe, and the tip of the probe constitutes a sensor unit that detects an electric field.

JP 2007-278820 A JP 2012-168079 A JP 2013-44660 A

  In the conventional electric field detection probe described above, an electric field including components in all directions that can propagate from the tip of the coaxial tube into the coaxial tube is detected. Therefore, a conventional electric field detection probe cannot detect an electric field having a specific direction component with high accuracy. Therefore, it is required to be able to detect the electric field of the desired direction component.

  In one aspect, an electric field sensing probe is provided. This probe is a probe having a coaxial structure, and includes a coaxial tube and a sensor unit. The coaxial tube has a tip portion. Further, the coaxial tube has a center conductor, a dielectric, an outer conductor, and an electromagnetic wave absorber. The dielectric covers the outer periphery of the central conductor, the outer conductor covers the outer periphery of the dielectric, and the electromagnetic wave absorber covers the outer periphery of the outer conductor. The center conductor is short-circuited to the outer conductor at the tip of the coaxial tube. The coaxial tube has a sensor portion at a position away from the tip portion. In the sensor unit, a slot that extends in the circumferential direction with respect to the central axis of the coaxial waveguide and exposes the dielectric is formed in the electromagnetic wave absorber and the outer conductor.

  In the electric field detection probe according to one aspect, in the sensor unit, the two end faces of the outer conductor on both sides of the slot face each other, and the electric field of the component in the direction in which the two end faces face each other is mainly detected. Therefore, it is possible to detect the electric field of the desired direction component by matching the direction in which these end faces face each other to the direction of the electric field component to be detected. In addition, since the electromagnetic wave is absorbed by the electromagnetic wave absorber in a region other than the sensor unit, it is possible to suppress the influence of disturbance on the electric field to be detected by the sensor unit.

In one embodiment, the distance from the tip of the coaxial tube to the sensor portion in the longitudinal direction of the coaxial tube is λ _g /4×A−0.1×λ _g or more, λ _g /4×A+0.1×λ _g The distance in the following range, where λ _g is the wavelength of the detected electromagnetic wave in the dielectric, and A is an integer of 1 or more. In the probe of this form, if A is an even number, the intensity of the signal output from the probe increases. If A is an odd number, the current flowing in the probe is small. Therefore, disturbance of the electromagnetic field in the space where the probe is arranged can be suppressed.

  In one form, the slot may expose the entire periphery of the dielectric in the sensor section. According to this form, the intensity of the signal output from the probe increases. On the other hand, in another embodiment, the slot may partially expose the dielectric in the sensor portion. In other words, in the sensor unit, the electromagnetic wave absorber and the outer conductor may be partially removed.

  In one form, the width | variety of the slot in the longitudinal direction of a coaxial tube may be 1 mm or more and 2 mm or less. By setting the slot width to 1 mm or more, it is possible to suppress discharge between the end faces of the outer conductor. Further, by setting the slot width to 2 mm or less, it becomes possible to suppress the detection of the electric field of the direction component other than the intended direction component.

  In another aspect, a method for sensing an electric field is provided. This method includes placing the probe in one of the above-described aspects or various forms in a space where electromagnetic waves are generated.

  In yet another aspect, a processing apparatus for processing an object to be processed using a microwave is provided. This processing apparatus includes a processing container, a holder that supports an object to be processed in the processing container, and means for introducing a microwave into the processing container. In addition, the processing apparatus is a probe of one of the above-described side surfaces or various forms, and further includes the probe provided so that the sensor unit is positioned in the processing container.

  As described above, it is possible to detect an electric field of a desired direction component.

It is a perspective view of the probe concerning one embodiment. It is sectional drawing of the probe which concerns on one Embodiment. It is a figure for demonstrating simulation. It is a graph which shows a simulation result. It is a figure for demonstrating simulation. It is a graph which shows a simulation result. It is a figure which shows the processing apparatus which concerns on one Embodiment. It is a figure which illustrates the composition of high voltage power supply part PS.

  Hereinafter, various embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a perspective view of a probe according to an embodiment. FIG. 2 is a cross-sectional view of a probe according to an embodiment. A probe 1 shown in FIGS. 1 and 2 is a probe for detecting an electric field, which is disposed in a space in which electromagnetic waves propagate. The probe 1 has a coaxial structure, and includes a coaxial tube 2 having a distal end portion 2 a and a sensor unit 3.

  The coaxial tube 2 includes a center conductor 4, a dielectric 5, an outer conductor 6, and an electromagnetic wave absorber 7. The center conductor 4 is made of a conductive material. The center conductor 4 has an elongated cylindrical shape, and extends from the distal end portion 2a in the direction in which the center axis AX of the coaxial tube 2 extends (hereinafter referred to as “axis direction”). The central axis of the central conductor 4 substantially coincides with the central axis AX of the coaxial tube 2.

  The dielectric 5 covers the outer periphery of the center conductor 4. That is, the dielectric 5 has a substantially cylindrical shape, and its inner surface is in contact with the outer peripheral surface of the center conductor 4. The dielectric 5 can be made of a material having a relative dielectric constant of 2.0 to 2.2. For example, the dielectric 5 can be composed of polytetrafluoroethylene or polyethylene.

  The outer conductor 6 is made of a conductive material. The outer conductor 6 covers the outer periphery of the dielectric 5. That is, the outer conductor 6 has a substantially cylindrical shape, and its inner surface is in contact with the outer peripheral surface of the dielectric 5. Further, the outer conductor 6 extends in the direction intersecting the axis AX at the distal end portion 2a. That is, the outer conductor 6 has a closed shape at the tip 2a. The center conductor 4 is short-circuited to the outer conductor 6 at the tip 2a. That is, the center conductor 4 is coupled to the outer conductor 6 at the tip 2a.

  The electromagnetic wave absorber 7 is made of a material that absorbs electromagnetic waves. In one embodiment, the electromagnetic wave absorber 7 is composed of a carbon microcoil (CMC). The electromagnetic wave absorber 7 covers the outer periphery of the outer conductor 6. The electromagnetic wave absorber 7 has a substantially cylindrical shape closed at the front end portion 2a, and covers the outer peripheral surface extending in the axial direction of the outer conductor 6 and the outer surface of the outer conductor 6 at the front end portion 2a. As the electromagnetic wave absorber 7, in addition to the carbon microcoil (CMC), a magnetic loss material (ferrite wave absorber, alloy wave absorber, rare earth magnet compound, etc.) or dielectric loss material (wave absorber, polymer) Material, etc.) can be used.

  The coaxial tube 2 has a sensor portion 3 at a position away from the distal end portion 2a in the axial direction. A slot SL is formed in the sensor unit 3. The slot SL is formed in the electromagnetic wave absorber 7 and the outer conductor 6 so as to extend in the circumferential direction with respect to the axis AX, and the dielectric 5 is exposed. Therefore, the electromagnetic wave absorber 7 has a first portion 7a and a second portion 7b. The first portion 7a extends on the tip end 2a side with respect to the slot SL, and the second portion 7b extends so as to sandwich the slot SL between the first portion 7a and the second portion 7b. doing.

  The outer conductor 6 has a first portion 6a and a second portion 6b. The first portion 6a extends on the tip end 2a side with respect to the slot SL, and the second portion 6b extends so as to sandwich the slot SL between the first portion 6a and the second portion 6b. doing. The outer conductor 6 has an end face 6e and an end face 6f. The end surface 6e is an end surface of the first portion 6a, and the end surface 6f is an end surface of the second portion 6b. The end face 6e and the end face 6f face each other through the slot SL.

  In the probe 1, an electric field between the end face 6e and the end face 6f is detected, and a signal based on the electric field is output. Therefore, in the probe 1, an electric field mainly having a component in the direction in which the end face 6e and the end face 6f face each other, that is, the axial direction is detected. Further, in the probe 1, since the internal coaxial cable structure is covered with the electromagnetic wave absorber 7, it is possible to suppress the influence of disturbance on the electric field to be detected by the sensor unit 3.

  In one embodiment, the slot SL is formed so as to expose the entire circumference of the dielectric 5 in the sensor unit 3. According to this form, the intensity of the signal output from the probe 1 increases. In another embodiment, the slot SL may partially expose the dielectric 5 in the sensor unit 3. That is, the slot SL may be formed by partially removing the outer conductor 6 and the electromagnetic wave absorber 7 in the circumferential direction.

In one embodiment, the distance L1 from the distal end 2d to the slot SL (center position of the slot SL) in the longitudinal direction of the coaxial tube 2, that is, the axial direction, is λ _g /4×A−0.1×λ _g or more. , Λ _g /4×A+0.1×λ _g or less. Here, λ _g is the wavelength of the electromagnetic wave in the dielectric 5, and A is an integer of 1 or more. If A is an even number, the intensity of the signal output from the probe 1 increases. On the other hand, if A is an odd number, the current flowing in the probe 1 becomes small. Therefore, disturbance of the electromagnetic field in the space where the probe 1 is disposed can be suppressed. Note that when the dielectric 5 is made of polytetrafluoroethylene and the frequency of the electromagnetic wave is 5.8 GHz, the relative permittivity of the dielectric 5 is about 2, and thus λ _g is about 37 mm. . In a more detailed example, A is 3 and the distance L1 is about 27 mm.

  In an embodiment, the width L2 of the slot SL in the longitudinal direction of the coaxial tube 2, that is, the axial direction may be 1 mm or more and 2 mm or less. By setting the width of the slot SL to 1 mm or more, it becomes possible to suppress the discharge between the end face 6e and the end face 6f of the outer conductor 6. Further, by setting the width of the slot SL to 2 mm or less, it becomes possible to suppress detection of an electric field of a direction component other than the intended direction component.

  In the method of detecting an electric field using the probe 1 described above, the sensor unit 3 is disposed at a desired position in a space where electromagnetic waves are generated. Further, the longitudinal direction of the probe 1 is made to substantially coincide with the direction of the electric field component to be detected. Thereby, it is possible to detect an electric field of a desired direction component at a desired position. Then, by inputting the signal from the probe 1 to the signal processing apparatus connected to the probe 1, it is possible to measure the electric field strength of the intended direction component.

  Hereinafter, a simulation performed for evaluating the probe 1 will be described. First, as shown in FIG. 3, an electromagnetic wave EM having a frequency of 5.8 GHz is propagated to an input end of a rectangular waveguide at an input power of 1 W, and a state in which the sensor unit 3 of the probe 1 is inserted into the waveguide is simulated. did. The end of the rectangular waveguide was set to a non-reflection end. In this simulation, a current (hereinafter referred to as “probe current”) flowing through the probe 1 when the distance from the tip 2d of the probe 1 to the slot SL is variously changed is obtained.

FIG. 4 is a graph showing simulation results. In FIG. 4, the horizontal axis is the distance L1, and the vertical axis is the probe current. As shown in FIG. 4, as a result of the simulation, the probe current was low when the distance L1 was an odd multiple of λ _g / 4. In addition, the probe current was low when the distance L1 was within a range of approximately ± 10% of λ _g with respect to an odd multiple of λ _g / 4. Therefore, the distance L1 is λ _g /4×A-0.1×λ _g or more, when the distance in the range of λ _g /4×A+0.1×λ _g, it is possible to reduce the probe current It was confirmed that the electromagnetic field in the space in which the probe 1 is arranged is suppressed from being disturbed.

  Next, as shown in FIG. 5A, an electromagnetic wave EM having a frequency of 5.8 GHz is propagated to the input end of the rectangular waveguide at an input power of 1 W, and the longitudinal direction of the rectangular waveguide and the direction of the electric field E are The probe current when the longitudinal direction of the probe 1 was made to coincide with the direction perpendicular to the direction and the probe 1 was moved in the direction D1 in the figure was obtained by simulation. In this simulation, the distance L1 of the probe 1 is set to 15 mm, and the position of the sensor unit 3 is made to coincide with the center level in the height direction of the rectangular waveguide (the height direction in FIG. 5A). . Further, as shown in FIG. 5B, an electromagnetic wave EM having a frequency of 5.8 GHz is propagated to the input end of the rectangular waveguide at an input power of 1 W, and the longitudinal direction of the probe 1 is made to coincide with the direction of the electric field E. Thus, the probe current when the probe 1 was moved in the direction D2 in the figure was obtained by simulation. In this simulation as well, the position of the sensor unit 3 was made to coincide with the center level in the height direction of the rectangular waveguide (the height direction in FIG. 5B).

  FIG. 6 is a graph showing the result of the simulation. The graph showing the result of the simulation described with reference to FIG. 5A is shown in FIG. 6A, and FIG. A graph showing the result of the simulation described above is shown in FIG. In the graph of FIG. 6A, the horizontal axis Y0 is the origin (Y0) of the position in the D1 direction of one of the pair of surfaces of the rectangular waveguide facing in the D1 direction of FIG. = 0 mm) is the position of the sensor unit 3 in the D1 direction, and the vertical axis is the probe current. Note that Y0 being 15 mm indicates that the position of the sensor unit 3 coincides with the position of the one surface of the rectangular waveguide. In the graph of FIG. 6B, Y2 on the horizontal axis is the origin (Y2 = 0 mm) between the center position between the pair of faces of the rectangular waveguide facing in the D2 direction of FIG. Is the position of the sensor unit 3 in the D2 direction, and the vertical axis is the probe current. As shown in FIG. 6A, as a result of the simulation, it was confirmed that the electric field was not detected when the longitudinal direction of the probe 1 was orthogonal to the direction of the electric field E. Further, as shown in FIG. 6B, according to the probe 1, it was confirmed that the electric field was detected when the longitudinal direction of the probe 1 coincided with the direction of the electric field E. From this, it has been confirmed that the probe 1 can detect the electric field in the intended direction.

  Hereinafter, an embodiment of a processing apparatus using microwaves will be described. FIG. 7 is a diagram illustrating a processing apparatus according to an embodiment. A processing apparatus 10 shown in FIG. 7 is an apparatus for performing a heat treatment on an object to be processed (hereinafter also referred to as “wafer W”), and is an example of a processing apparatus that can employ the probe 1.

  The processing apparatus 10 includes a processing container 12, an introduction unit 14, a holder 16, and a rotation driving unit 18. The processing container 12 defines a processing space S. In the processing apparatus 10, the wafer W is heated in the processing space S. The processing container 12 is made of, for example, a metal material. For example, the processing container 12 can be made of aluminum, an aluminum alloy, stainless steel, or the like.

  The processing container 12 includes a side wall portion 12a, a ceiling portion 12b, and a bottom portion 12c. The ceiling part 12b defines the processing space S from above. A plurality of microwave introduction ports 12d are formed in the ceiling portion 12b. The bottom 12c defines the processing space S from below. An exhaust port 12e is formed in the bottom portion 12c. The side wall part 12a defines the processing space S from the side, and is interposed between the ceiling part 12b and the bottom part 12c. A port 12f is formed in the side wall portion 12a. The port 12f is a passage for loading and unloading the wafer W through the port 12f. This port 12f can be opened and closed by a gate valve GV.

  In one example, the side wall portion 12a has a rectangular tube shape. In this example, the processing space S is a cubic space. The inner surface of the side wall portion 12a functions as a microwave reflection surface. For example, the inner surface of the side wall portion 12a and further the inner surfaces of the ceiling portion 12b and the bottom portion 12c are mirror-finished. Thereby, the reflection efficiency of the radiant heat from the wafer W can be improved. Moreover, since the surface area of the inner surface of the processing container 12 is thereby reduced, the absorption of microwaves by the walls of the processing container 12 can be reduced, and the microwave reflection efficiency can be improved. As a result, the heating efficiency of the wafer W is increased.

  A holder 16 is provided in the processing container 12. The holder 16 is configured to support the wafer W. The holder 16 is supported by the shaft 22. The shaft 22 penetrates the bottom 12c and extends in the vertical direction. The upper end portion of the shaft 22 is coupled to the approximate center of the holder 16. Further, the lower end portion of the shaft 22 is coupled to the movable connecting portion 24. The movable connecting portion 24 connects the elevating drive unit 26 and the rotary drive unit 18. The elevating drive unit 26 is configured to displace the shaft 22 up and down in the vertical direction. Further, the rotation drive unit 18 is configured to rotate the shaft 22 around the center axis (that is, the rotation axis) of the shaft 22. The rotation drive unit 18 rotates the shaft 22 so that the holder 16 rotates around the center of the holder 16. Note that a sealing mechanism 12g such as a bellows may be provided at the bottom 12c of the processing container 12 in order to seal the hole through which the shaft 22 passes.

  An exhaust device 28 is connected to the exhaust port 12e of the bottom 12c. The exhaust device 28 has a vacuum pump such as a dry pump. The exhaust device 28 can be connected to the exhaust port 12 e via the pressure adjustment valve 30 and the exhaust pipe 32. The processing apparatus 10 may heat the wafer W under an atmospheric pressure environment. In this case, instead of the vacuum pump, an exhaust facility provided in a facility where the processing apparatus 10 is installed can be used as the exhaust device 28.

The processing apparatus 10 may further include a gas supply mechanism 34. The gas supply mechanism 34 may include a gas source, a flow controller, and a valve. The gas supply mechanism 34 is connected to the inside of the processing container 12 via one or more pipes 36. The gas supply mechanism 34 can supply the gas into the processing container 12 by controlling the flow rate of the gas from the gas source. The gas supply mechanism 34 can supply a gas such as N ₂ , Ar, He, Ne, O ₂ , and H ₂ as a processing gas or a cooling gas.

  In addition, the processing apparatus 10 may further include a current plate 38. The current plate 38 is provided between the holder 16 and the side wall 12a. The rectifying plate 38 is formed with a plurality of through holes 38a extending in the vertical direction. The rectifying plate 38 can be made of, for example, a metal material such as aluminum, an aluminum alloy, or stainless steel.

  The introduction unit 14 introduces the microwave into the processing container 12 through the above-described microwave introduction port 12d. The introduction unit 14 includes one or more microwave units MU and a high voltage power supply unit PS. In the example illustrated in FIG. 7, the introduction unit 14 includes a plurality of microwave units MU.

  The microwave unit MU includes a magnetron 40, a waveguide 41, and a transmission window 42. The magnetron 40 is connected to the high voltage power supply unit PS. FIG. 8 is a diagram illustrating the configuration of the high voltage power supply unit PS. As shown in FIG. 8, the high voltage power supply unit PS includes an AC-DC conversion circuit 51, a switching circuit 52, a switching controller 53, a step-up transformer 54, and a rectifier circuit 55.

  The AC-DC conversion circuit 51 is a circuit that rectifies alternating current (for example, three-phase 200 V alternating current) from a commercial power source and converts it into direct current having a predetermined waveform. The AC-DC conversion circuit 51 is connected to the switching circuit 52. The switching circuit 52 is a circuit that controls on / off of the direct current converted by the AC-DC conversion circuit 51. In the switching circuit 52, a phase shift type PWM (Pulse Width Modulation) control or PAM (Pulse Amplitude Modulation) control is performed by the switching controller 53 to generate a pulsed voltage. The step-up transformer 54 boosts the voltage output from the switching circuit 52 to a voltage having a predetermined magnitude. The rectifier circuit 55 is a circuit that rectifies the voltage boosted by the step-up transformer 54 and supplies the rectified voltage to the magnetron 40.

  The magnetron 40 generates microwaves based on the high voltage applied from the high voltage power supply unit PS. The frequency of this microwave is a frequency of 2.45 GHz or 5.8 GHz, for example. A waveguide 41 is connected to the magnetron 40.

  The waveguide 41 transmits the microwave generated by the magnetron 40 into the processing container 12. The transmission window 42 is fixed to the ceiling portion 12b so as to close the microwave introduction port 12d. The transmission window 42 is made of a dielectric material. For example, the transmission window 42 is made of quartz. The microwave transmitted through the waveguide 41 is introduced into the processing container 12 through the transmission window 42.

  The microwave unit MU further includes a circulator 43, a detector 44, a tuner 45, and a dummy load 46. The circulator 43 guides the microwave from the magnetron 40 toward the processing container 12, while guiding the reflected wave from the processing container 12 to the dummy load 46. The dummy load 46 converts the reflected wave guided from the circulator 43 into heat.

  The detector 44 is for detecting a reflected wave in the waveguide 41. The detector 44 can be constituted by, for example, an impedance monitor, for example, a standing wave monitor. The standing wave monitor detects the electric field of the standing wave in the waveguide 41. Based on the detection result of the standing wave monitor, the reflected wave can be detected. The detector 44 may be constituted by a directional coupler capable of detecting traveling waves and reflected waves.

  The tuner 45 matches the impedance between the magnetron 40 and the processing container 12. Impedance matching by the tuner 45 is performed based on the detection result of the detector 44. For example, the tuner 45 can adjust the impedance by adjusting the amount of protrusion of the conductor plate into the waveguide 41.

  The processing apparatus 10 may further include one or more radiation thermometers RT. The radiation thermometer RT has a light receiving end RTE provided in the vicinity of the wafer W. Further, the radiation thermometer RT has a photodetector and outputs a signal corresponding to the intensity of light received by the light receiving end RTE from the photodetector. Further, the radiation thermometer RT includes a temperature calculation unit that calculates the temperature of the wafer W based on a signal from the photodetector.

  The processing apparatus 10 further includes the probe 1 described above. The probe 1 is provided so that the sensor unit 3 is located in the processing container 12. In the embodiment shown in FIG. 7, the probe 1 passes through the side wall portion 12a, and the sensor unit 3 is disposed in the processing container 12 so that the longitudinal direction of the probe 1 coincides with the horizontal direction. However, the arrangement of the probe 1 can be changed according to the position in the processing container 12 where the electric field is to be detected and the direction of the electric field component to be detected. Further, the number of probes 1 provided in the processing apparatus 10 can be changed according to the number of positions where the electric field should be detected.

  A signal processing device 9 is connected to the probe 1. The signal processing device 9 receives a signal output from the probe 1 and converts the signal into a signal input to the control unit Cnt. For example, the signal processing device 9 may have various units such as an A-D converter.

  Further, the processing apparatus 10 may further include a control unit Cnt. The control unit Cnt can be configured by a computer device, for example. The control unit Cnt controls each unit of the processing device 10. Specifically, the control unit Cnt sends a control signal to each part of the processing apparatus 10 in order to control the gas flow rate, the pressure in the processing container 12, the rotational speed of the holder 16, the exhaust amount of the exhaust apparatus 28, and the like. . Further, the control unit Cnt can adjust the microwave output to be introduced into the processing container 12 in response to a signal from the signal processing device 9 and / or a signal from the radiation thermometer RT. That is, the control unit Cnt can adjust the microwave output introduced into the processing container 12 by receiving a signal corresponding to the electric field in the processing container 12 and / or a signal corresponding to the temperature of the wafer W. It is.

  Although various embodiments have been described above, various modifications can be made without being limited to the above-described embodiments. For example, although the processing apparatus 10 described above is a heat processing apparatus, the probe 1 can be used to detect an electric field in a processing container of an arbitrary processing apparatus that processes an object to be processed using microwaves. Is possible.

  DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Coaxial tube, 2a ... Tip part, 2d ... Tip, 3 ... Sensor part, 4 ... Center conductor, 5 ... Dielectric, 6 ... Outer conductor, 6e, 6f ... End face, 7 ... Electromagnetic wave absorber, SL ... Slot, 9 ... Signal processing device, 10 ... Processing device, 12 ... Processing container, 14 ... Introduction part, 16 ... Holder.

Claims (7)

A coaxial probe for electric field detection,
A coaxial tube having a tip, and
A sensor unit provided in the coaxial tube;
With
The coaxial tube is
A central conductor;
A dielectric covering the outer periphery of the central conductor;
An outer conductor covering the outer periphery of the dielectric;
An electromagnetic wave absorber covering the outer periphery of the outer conductor;
Have
The central conductor is short-circuited to the outer conductor at the tip;
The coaxial tube has a sensor part at a position away from the tip part,
In the sensor unit, a slot is formed in the electromagnetic wave absorber and the outer conductor that extends in a circumferential direction with respect to the central axis of the coaxial waveguide and exposes the dielectric.
probe. The distance from the tip of the coaxial tube to the sensor portion in the longitudinal direction of the coaxial tube is in the range of λ _g /4×A−0.1×λ _g or more and λ _g /4×A+0.1×λ _g or less. The probe according to claim 1, wherein λ _g is a wavelength of the detected electromagnetic wave in the dielectric, and A is an integer of 1 or more.   The probe according to claim 2, wherein A is an odd number.   The probe according to claim 1, wherein the slot exposes the entire circumference of the dielectric in the sensor unit.   The probe according to any one of claims 1 to 4, wherein a width of the slot in a longitudinal direction of the coaxial tube is 1 mm or more and 2 mm or less.   A method for detecting an electric field, comprising disposing the probe according to claim 1 in a space where electromagnetic waves are generated. A processing apparatus for processing an object to be processed using a microwave,
A processing vessel;
A holder for supporting an object to be processed in the processing container;
Means for introducing microwaves into the processing vessel;
The probe according to any one of claims 1 to 5, wherein the probe is provided so that a sensor unit is positioned in the processing container;
A processing apparatus comprising:

Images