Plasma processing apparatus and plasma processing method

Abstract

The circumferential uniformity of plasma processing is improved by minimizing the circumferential deviation of the microwave electric field intensity at the outer circumferential part of the wafer. In the plasma processing device, TE11 mode microwaves are coaxially introduced into a processing chamber through a circular waveguide tube, a 90-degree phase difference plate of the microwaves is arranged from the upper part in the circular waveguide tube, and a 180-degree phase difference plate is arranged below the 90-degree phase difference plate. In the plasma processing device, a 180-degree phase difference plate is further connected with a rotation driving mechanism. In the plasma processing device, a detector for detecting the deviation of the electric field intensity in the circumferential direction is further connected below the 180-degree phase difference plate, and the plasma processing device is provided with a control unit for adjusting the rotation angle of the 180-degree phase difference plate so as to minimize the variation of the axial symmetry of the electric field intensity detected by the detector.

Description

Technical Field

[0001] The present invention relates to a plasma processing apparatus and a plasma processing method for processing a substrate-shaped sample such as a semiconductor wafer arranged in a processing chamber using plasma formed in a vacuum container such as etching. Background Art

[0002] The structure of semiconductor devices is becoming increasingly miniaturized and complex in order to achieve both improved computing power and low power consumption. As a result of the complication of the manufacturing process and the high-difficulty processing required, the manufacturing cost of semiconductor devices increases. In order to reduce manufacturing costs, it is sought to increase the number of high-quality semiconductor devices manufactured from a semiconductor wafer (hereinafter also referred to as a unit or wafer) to improve mass production. In order to increase the number of semiconductor devices obtained from a wafer, it is necessary to ensure good process uniformity within the wafer surface. In particular, since a large number of semiconductor devices can be obtained at the periphery of the wafer, it is important to ensure good process uniformity in the circumferential direction in order to uniformly process the periphery of the wafer.

[0003] In the manufacture of semiconductor devices, plasma treatments such as plasma etching, plasma CVD (Chemical Vapor Deposition), and plasma ashing are widely used. In the generation of plasma, various methods are known, such as ICP (Inductively Coupled Plasma), CCP (Capacitively Coupled Plasma), ECR (Electron Cyclotron Resonance), and surface wave excitation plasma, as methods of applying DC voltage between electrodes and using high-frequency power to generate plasma.

[0004] In a plasma processing device using microwaves, in order to generate plasma that is uniform in the circumferential direction relative to the central axis of the wafer, microwaves are often introduced from the central axis of the processed wafer to the direction of the processed surface of the processed wafer. However, depending on the mode in which microwaves propagate in the waveguide, the electric field distribution is not necessarily axisymmetric. For example, in the fundamental mode of microwaves propagating inside a circular waveguide, that is, the TE11 mode, the electric field distribution of microwaves is non-axisymmetric. In such a case, in order to make the electric field distribution axisymmetric, it is effective to rotate the polarization plane to form a circularly polarized wave.

[0005] The structure of Patent Document 1 is a structure in which a microwave rotating generator (dielectric plate) is provided inside a circular waveguide in order to make the electric field distribution inside the circular waveguide axially symmetrical.

[0006] Patent Document 2 shows a structure in which a plurality of short stubs are provided inside a circular waveguide and the amount of the short stubs inserted is controlled. The axial symmetry of the electric field distribution inside the circular waveguide can be improved by the amount of the short stubs inserted. The axial symmetry of the electric field distribution can be ensured by adjusting the amount of the short stubs inserted.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2010-50046

[0010] Patent Document 2: JP-A-2003-110312

[0011] Non-patent literature

[0012] Non-patent document 1: Microwave Circuit (authored by Kunihiro Suetsu and Shuichi Hayashi, Ohmsha, 1958) Summary of the invention

[0013] Problems to be solved by the invention

[0014] In a plasma processing device that generates plasma using a high-frequency electric field such as microwaves, as described in Patent Document 1 and Non-Patent Document 1, a microwave rotary generator and a 90-degree phase difference plate composed of a dielectric plate are shown as a means of forming a circularly polarized wave. In this method, when the reflected wave from the outlet of the waveguide is small, an axisymmetric electric field distribution can be expected. However, when the reflected wave coming back from the processing chamber is large, the electric field vibration direction of the microwave incident on the microwave rotary generator and the 90-degree phase difference plate will deviate from the direction envisioned during the design, and sometimes the axisymmetry of the electric field distribution will be destroyed. For example, in a plasma processing device, depending on the conditions used in the processing, sometimes the microwave is not completely absorbed by the plasma and returns to the waveguide. In order to ensure the axisymmetry of the electric field distribution under various discharge conditions, it is necessary to dynamically control the electric field distribution.

[0015] As a method of dynamically controlling, there is a method of using a short stub described in Patent Document 2. As a problem of the method of changing the insertion amount of the short stub, it can be cited that a driving mechanism is required according to the number of short stubs, and the control method becomes complicated. In addition, if a short stub and a driving mechanism are provided, the structure will protrude to the outside of the circular waveguide by the length of the short stub, and the footprint of the device will increase.

[0016] An object of the present invention is to provide a technique for minimizing the circumferential deviation of microwave electric field intensity at the periphery of a wafer, thereby improving the circumferential uniformity of plasma processing.

[0017] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0018] Means for solving problems

[0019] The outline of the representative aspects of the present invention will be briefly described as follows.

[0020] According to one embodiment, a plasma processing device coaxially introduces a microwave of a TE11 mode into a processing chamber via a circular waveguide tube, in which a 90° phase difference plate of a microwave is arranged from the top in the circular waveguide tube, and a 180° phase difference plate is arranged below it. In addition, a rotation drive mechanism is connected to the 180° phase difference plate. Furthermore, a detector (measuring unit) for detecting the deviation of the circumferential electric field intensity is connected below the 180° phase difference plate, having: a control unit, which adjusts the rotation angle of the 180° phase difference plate so that the variation of the axial symmetry of the electric field intensity detected by the detector is suppressed to a minimum.

[0021] Effects of the Invention

[0022] The circumferential deviation of the microwave electric field intensity at the periphery of the wafer is minimized, thereby improving the circumferential uniformity of the plasma treatment, thereby increasing the number of high-quality semiconductor devices manufactured from one semiconductor wafer, thereby improving the mass productivity of semiconductor devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view of an etching device according to a first embodiment of the present invention.

[0024] Figure 2 It is a cross-sectional view of a 90° phase difference plate and a circular waveguide.

[0025] Figure 3 This is a diagram showing the effect of the 90° phase difference plate.

[0026] Figure 4 It is a cross-sectional view of a 180° phase difference plate and a circular waveguide.

[0027] Figure 5 This is a diagram showing the effect of a 180° phase difference plate.

[0028] Figure 6 This is a diagram showing the effect of a 180° phase difference plate.

[0029] Figure 7 This is an enlarged cross-sectional view from the automatic matching device to the circular waveguide.

[0030] Figure 8 It is a cross-sectional view of a plasma processing apparatus provided with a circularly polarized wave detector according to a second embodiment of the present invention.

[0031] Fig. 9This is an enlarged cross-sectional view of a circularly polarized wave detector. DETAILED DESCRIPTION

[0032] The following is an explanation of the embodiments of the present invention using the accompanying drawings. However, in the following description, the same components are marked with the same reference numerals, and repeated descriptions are sometimes omitted. In addition, in order to make the description clearer, the accompanying drawings are sometimes schematically shown compared with the actual mode, but this is only an example and does not limit the interpretation of the present invention.

[0033] Example 1

[0034] exist Figure 1 FIG. 2 is a cross-sectional view of an etching device according to a first embodiment of the present invention. Figure 1 In the etching device, i.e., the plasma processing device 100, microwaves are oscillated from a microwave source 1, and are transmitted from an isolator 2, an automatic matching device 3, and a rectangular waveguide tube 4 to a circular waveguide tube 5 via a circular-rectangular converter 6. In this embodiment, microwaves of 2.45 GHz commonly used in industry are used. The isolator 2 is used to protect the microwave source 1 from the reflected waves of the microwaves. The automatic matching device 3 is used to adjust the load impedance, suppress the reflected waves, and thus efficiently supply the microwaves. In order to facilitate the handling of the microwave propagation phenomenon, the size of the waveguide cross section is specified so that only the TE10 mode of the fundamental mode is propagated in the rectangular waveguide tube 4, and only the TE11 mode of the fundamental mode is propagated in the circular waveguide tube 5. A 90-degree phase difference plate 7 and a 180-degree phase difference plate 9 connected to a rotation drive mechanism 8 are provided in the circular waveguide tube 5. The microwave introduced into the circular waveguide 5 propagates to the 90° phase difference plate 7, the 180° phase difference plate 9 and the cavity 10, and is introduced into the roughly cylindrical plasma processing chamber 13 (also called a processing container) through the microwave introduction window 11 and the shower plate 12. The circular waveguide 5 is arranged symmetrically with respect to the plasma processing chamber 13.

[0035] A conductor is used as a material reflecting microwaves in the cavity 10. As the material of the cavity 10, aluminum is used, for example.

[0036] In order to protect the side wall of the plasma processing chamber 13 from plasma, an inner cylinder 14 is provided inside the side wall of the plasma processing chamber 13. Quartz is used as a material with high plasma resistance for the inner cylinder 14 located near the plasma. Alternatively, yttrium oxide, aluminum oxide, yttrium fluoride, aluminum fluoride, aluminum nitride, etc. can be used as a material with high plasma resistance.

[0037] Quartz is used as a material that transmits microwaves as the material of the microwave introduction window 11 and the shower plate 12. Alternatively, other dielectric materials may be used as long as they are materials that transmit microwaves. Alternatively, yttrium oxide, aluminum oxide, yttrium fluoride, aluminum fluoride, aluminum nitride, etc. may be used as materials with high plasma resistance.

[0038] Gas is supplied from a gas supply unit 15 between the microwave introduction window 11 and the shower plate 12. The gas supply unit 15 includes a function of supplying a desired flow rate through a mass flow controller. In addition, the type of gas used is appropriately selected according to the film to be processed, and a plurality of gas types are supplied in combination at a given flow rate.

[0039] The shower plate 12 is provided with a plurality of gas supply holes, and the gas is supplied to the plasma processing chamber 13 through the gas supply holes. The supplied gas is evacuated by the turbomolecular pump 17 through the conductance control valve 16 .

[0040] A substrate stage and high-frequency electrode 19 for mounting a substrate 18 to be processed is provided at the lower part of the plasma processing chamber 13, and an insulating plate 29 is provided at the lower part thereof, and a bias power is supplied to the substrate stage and high-frequency electrode 19 from a bias power supply 20 via an automatic matching device 21. The substrate 18 to be processed is a semiconductor wafer as a substrate-shaped sample. The central axis of the circular waveguide 5 coincides with the central axis of the plasma processing chamber 13. Furthermore, the central axis of the plasma processing chamber 13 is arranged axially symmetrically so that the central axis of the substrate stage and high-frequency electrode 19 coincides with the central axis of the semiconductor wafer mounted on the substrate stage and high-frequency electrode 19.

[0041] The bias power is adjusted to control the energy of the ions incident on the substrate 18 to be processed so that the desired etching can be performed. The substrate stage and high-frequency electrode 19 is provided with an adsorption mechanism and a temperature adjustment unit for the substrate 18 to be processed (not shown). In order to perform the desired etching, the temperature of the substrate 18 to be processed is adjusted as needed.

[0042] In order to protect the outer periphery of the substrate stage and high-frequency electrode 19 from plasma, a susceptor 22 and a stage cover 23 are provided. Quartz is used as a material with high plasma resistance for the susceptor 22 and the stage cover 23. Plasma 24 is generated in the plasma processing chamber 13 by microwaves supplied from the microwave source 1, and the ions and radicals generated thereby are irradiated to the substrate 18 to be processed, thereby performing etching.

[0043] Next, the detailed structure and effect of the circular waveguide 5 are described. Figure 2 The detailed structure of the 90° phase difference plate 7 will be described. Figure 2 It is a top cross-sectional view of the circular waveguide 5 and the 90° phase difference plate 7. Consider the following situation: the microwave of the TE11 mode is introduced with the electric field vibration direction 30 in the y-axis direction in the figure, and propagates from the surface of the paper to the back surface. The 90° phase difference plate 7 is set at an angle of 45° rotated relative to the vibration direction of the electric field. Here, the y' axis is defined as the axis of the direction of the 90° phase difference plate 7, and the x' axis is defined as the axis in the direction perpendicular to the y' axis. The 90° phase difference plate 7 uses quartz as a dielectric material that transmits microwaves.

[0044] exist Figure 3 A graph showing the effect of a 90° phase difference plate is shown. Figure 3 (A) is the cross-sectional view of the circular waveguide on the x'-z plane. Figure 3 (B) is a cross-sectional view of the circular waveguide on the y'-z plane. Figure 3 In (A) and (B), the curve in the circular waveguide 5 represents the wave. Figure 3 (A) shows a wave with amplitude in the x' direction. Figure 3 (B) shows a wave with amplitude in the y' direction. Microwaves with amplitude in the y-axis direction can be expressed as a superposition of waves with equal amplitude and the same phase introduced in the x' and y' directions. If the microwave passes through the 90° phase difference plate 7, the phase difference between the wave with amplitude in the x' direction and the wave with amplitude in the y' direction becomes 90°. This is because the phase of the wave with amplitude in the y' direction lags by 90° when passing through the 90° phase difference plate 7.

[0045] This result means that a circularly polarized wave is formed. In addition, the height H1 of the 90° phase difference plate 7 needs to be set to an appropriate value so that the phase difference between the x' component wave and the y' component wave becomes 90°.

[0046] The height H1 of the 90° phase difference plate 7 is expressed by the following formula (1).

[0047] H1=λg / (4(√ε r -1)) (1)

[0048] Here, λg represents the wavelength of microwaves in a circular waveguide in a vacuum, and ε r is the dielectric constant of the 90° phase difference plate 7. For example, the wavelength in the tube for a microwave with a frequency of 2.45 GHz is 203 mm. If the dielectric constant of quartz is set to 3.8, H1 becomes 53.5 mm.

[0049] If the above is summarized, in the absence of reflection from plasma, a circularly polarized wave can be formed by using a 90° phase difference plate 7, and microwaves can be uniformly introduced in the circumferential direction. In the present embodiment, a rectangular parallelepiped-shaped phase difference plate is shown as a 90° phase difference plate 7, but as long as the purpose is to form a 90° phase difference, it may not necessarily be a rectangular parallelepiped shape. In addition, the 90° phase difference plate 7 partially reflects the microwaves at its end face, and sometimes the angle used to form a 90° phase difference deviates from 45°. That is, the angle at which the 90° phase difference plate 7 is set is not necessarily limited to an angle of 45° relative to the direction of electric field vibration, and the reflection coefficient of the microwaves corresponding to the 90° phase difference plate 7 is appropriately set to the optimal angle.

[0050] As in this embodiment, when the 90° phase difference plate 7 is arranged at 45° counterclockwise relative to the vibration direction of the electric field (refer to Figure 2 ), forming a left-handed circularly polarized wave.

[0051] Next, use Figure 4 The detailed structure of the 180° phase difference plate 9 connected to the rotation drive mechanism 8 will be described. Figure 4 It is a top cross-sectional view of a circular waveguide in the peripheral portion of a 180° phase difference plate 9. The circular waveguide 5 has a double structure (5-1, 5-2), consisting of an inner waveguide 5-1 and an outer waveguide 5-2 covering its outer periphery. The inner waveguide 5-1 supports the 180° phase difference plate 9, and the inner waveguide 5-1 and the 180° phase difference plate 9 can be rotated in the θ direction as a whole through the actuator 25 of the rotation drive mechanism 8. In addition, the rotation angle of the 180° phase difference plate 9 is monitored at any time by an encoder not shown in the figure. As the material of the 180° phase difference plate 9, for example, quartz is used as a material that transmits microwaves.

[0052] For example, the actuator 25 of the rotation drive mechanism 8 is an electromagnetic motor, and the connection portion with the inner waveguide 5-1 is a gear or belt structure. Alternatively, the actuator 25 may be an ultrasonic motor.

[0053] like Figure 4 As shown in FIG. 1 , the 180° phase difference plate 9 is inserted at an angle of θ relative to the x-axis. Here, the axis in the θ direction is defined as the x" axis, and the axis perpendicular to the x" axis is defined as the y" axis. Figure 5 The effect when the left-handed circularly polarized wave generated in the 90° phase difference plate 7 is incident on the 180° phase difference plate 9 will be described.

[0054] Figure 5 (A) is a cross-sectional view of a circular waveguide in the y"-z plane. Figure 5 (B) is a cross-sectional view of the circular waveguide in the x”-z plane. As a result of the microwave having amplitude on the x” axis being delayed by 180° in phase, a phase difference of 180° is generated between the wave of the x” component and the wave of the y” component at the exit of the 180° phase difference plate 9. Since the incident wave to the 180° phase difference plate 9 is a circularly polarized wave having a phase difference of 90°, as a result, the phase difference of the wave having electric field components on the x” axis and the y” axis becomes 90°+180°=270°. That is, this means that it is converted into a right-handed circularly polarized wave. The height H2 of the 180° phase difference plate needs to be set to an appropriate value so that the phase difference between the wave of the x” component and the wave of the y” component becomes 180°. The height H2 of the 180° phase difference plate 9 is expressed by the following formula (2).

[0055] H2=λg / (2(√ε r -1)) (2)

[0056] The 180° phase difference plate 9 has an effect of reversing the polarization direction of circularly polarized waves.

[0057] Furthermore, use Figure 6 This is to illustrate the effect of the 180° phase difference plate 9 in rotating the polarization plane of the linear polarized wave. Figure 6 As shown in FIG. 1 , consider the case where the insertion direction of the 180° phase difference plate 9 is set to the x-axis, and a linearly polarized wave having an electric field vibration direction 34 is incident in a direction at an angle α relative to the x-axis. At this time, by using the 180° phase difference plate 9 to retard the phase of the component wave in the x-axis direction, the microwave passing through the 180° phase difference plate 9 is converted into a linearly polarized wave having an electric field vibration direction 35 in a direction at an angle -α relative to the x-axis. That is, it means that if the rotation angle of the 180° phase difference plate 9 is adjusted, the angle of the polarization plane of the linearly polarized wave can be adjusted.

[0058] If the above is summarized, the 180° phase difference plate 9 has the effect of reversing the rotation direction of the incident circularly polarized wave. In addition, the 180° phase difference plate 9 has the effect of rotating the polarization plane of the incident linearly polarized wave. In the absence of a reflected wave from the outlet of the circular waveguide 5, the linearly polarized wave incident on the 90° phase difference plate 7 is converted into a left-handed circularly polarized wave, and is converted into a right-handed circularly polarized wave by the 180° phase difference plate 9.

[0059] Next, use Figure 7 The following describes the case where a reflected wave occurs from the outlet of the circular waveguide 5 . Figure 7 It is an enlarged cross-sectional view from the automatic matching device 3 to the exit of the circular waveguide 5. In the case of reflected waves, for example, it is assumed that the microwave supplied to the plasma processing chamber 13 is not absorbed by the plasma 24 and is reflected, or reflected by the wall of the plasma processing chamber 13. The reflected wave RW (RWx: x-axis component of the reflected wave RW, RWy: y-axis component of the reflected wave RW) propagates in the opposite path to the incident wave such as the circular waveguide 5, the 180-degree phase difference plate 9, the 90-degree phase difference plate 7, and the circular-rectangular converter 6. The microwave electric field in the circular waveguide 5 can be transmitted in two independent axes ( Figure 7 On the other hand, the rectangular waveguide 4 has a 1-axis direction ( Figure 7The electric field vibration direction of the circular waveguide 5 is the z-axis. That is, in the process of the wave propagating in the circular waveguide 5 being transmitted to the rectangular waveguide 4, one degree of freedom of the vibration direction of the electric field is lost. The TE11 mode having an electric field vibration direction in the y-axis direction corresponds to the electric field vibration direction 40 of the TE10 mode of the rectangular waveguide 4, and therefore can be propagated to the automatic matcher 3. On the other hand, the electromagnetic wave of the TE11 mode having an electric field vibration direction in the x-axis direction in the circular waveguide 5 cannot propagate in the rectangular portion of the circular-rectangular converter 6 and is reflected, and then incident on the 90-degree phase difference plate 7. That is, the microwave incident on the 90° phase difference plate 7 adds the wave of the TE11 mode having an electric field vibration direction in the y-axis direction and the reflected wave RW (RWx) in the circular-rectangular converter 6. As a result, in the case of incident reflected wave RW from the outlet of the circular waveguide 5, the axial symmetry of the circularly polarized wave is destroyed in the 90-degree phase difference plate 7.

[0060] As mentioned above, the rotation angle of the 180-degree phase difference plate 9 can be used to adjust the angle of the polarization plane of the linearly polarized wave, and therefore, the angle of the polarization plane of the microwave re-reflected in the circular-rectangular converter 6 can be adjusted. That is, the polarization plane of the wave incident on the 90° phase difference plate 7 is controlled, and as a result, the circumferential deviation of the electric field can be minimized. For example, if the 180° phase difference plate 9 is rotated during plasma processing, the circumferential deviation of the time-averaged electric field can be minimized. Alternatively, by adjusting the 180° phase difference plate 9 to the optimal angle corresponding to the processing conditions used in the plasma processing, the circumferential deviation of the electric field can be reduced.

[0061] In order to control the optimal angle, it is necessary to measure the circumferential deviation of the electric field. As an indirect measurement method, for example, the reflection coefficient and phase of the load can be monitored in the microwave automatic matcher 3, the reflection coefficient at the exit of the circular waveguide 5 can be estimated, and the rotation angle of the 180° phase difference plate can be adjusted according to the reflection coefficient. As a direct measurement method, an electric field measurement unit can also be set in the circular waveguide 5.

[0062] According to the plasma processing apparatus or plasma processing method involved in the first embodiment, the circumferential deviation of the microwave electric field intensity at the periphery of the wafer is minimized, and the circumferential uniformity of the plasma processing can be improved. As a result, the number of high-quality semiconductor devices manufactured from one semiconductor wafer can be increased, and thus the mass productivity of semiconductor devices can be improved.

[0063] Example 2

[0064] exist Figure 8 A cross-sectional view showing a plasma processing apparatus (etching apparatus) according to a second embodiment of the present invention. Figure 8 FIG. 2 is a cross-sectional view of a plasma processing device 100a in which a circular polarization wave detector 26 is provided. Figure 8As shown in the figure, the circular polarization wave detector 26 is arranged on the downstream side (exit side of the circular waveguide 5) of the 180° phase difference plate 9. By monitoring the state of the circular polarization wave by using the circular polarization wave detector 26, the optimal angle of the 180° phase difference plate 9 can be controlled. The circular polarization wave detector 26 can be regarded as a measurement unit for measuring the circumferential electric field in the circular waveguide 5.

[0065] use Fig. 9 A specific example of the circular polarization wave detector 26 is described below. In order to form the circular polarization wave detector 26, electric field detectors 27 are provided at a plurality of locations in the circular waveguide 5, and the circumferential deviation of the electric field is monitored by relative comparison of the electric fields determined and measured by a plurality of electric field detectors 27. As the electric field detector 27, for example, a mineral detector is used. With regard to the location where the electric field detector 27 is provided, at least three locations are provided on the circumference of the circular waveguide 5. In addition, in order to detect circularly polarized waves, it is necessary that the positions of the individual electric field detectors 27 are not linearly symmetrical. The measured value of the electric field detector 27 is input to the control unit (also referred to as the control unit) 28 for calculation processing. Based on the calculation processing, the control unit 28 sends a control signal for controlling the rotation angle of the 180° phase difference plate 9 to the rotation drive mechanism 8. Thus, the control unit 28 controls the rotation angle of the 180° phase difference plate 9 to minimize the circumferential deviation of the electric field. In addition, after utilizing Figure 8 as well as Fig. 9 In the plasma processing method of the plasma processing device, the angle of the 180-degree phase difference plate 9 is adjusted by the control unit 28 so as to minimize the circumferential deviation of the electric field measured by the circularly polarized wave detector 26 (or the electric field detector 27) as the measuring unit.

[0066] According to the plasma processing apparatus or the plasma processing method involved in the second embodiment, the same effects as those of the first embodiment can be obtained.

[0067] As mentioned above, the invention made by the inventors of the present invention has been specifically described based on the embodiments, but the present invention is not limited to the above-mentioned embodiment and embodiments, and various modifications are possible.

[0068] Industrial Applicability

[0069] The present invention can be applied to a plasma processing device for processing a sample on a substrate such as a semiconductor wafer by etching or the like.

[0070] Description of Reference Numerals

[0071] 1 Microwave source

[0072] 2 Isolator

[0073] 3 Automatic Matcher

[0074] 4 Rectangular waveguide

[0075] 5 Circular waveguide

[0076] 5-1 Inner waveguide

[0077] 5-2 Outer waveguide

[0078] 6 Circle to rectangle conversion machine

[0079] 7 90° phase difference plate

[0080] 8 Rotation drive mechanism

[0081] 9 180° phase difference plate

[0082] 10 Cavity

[0083] 11 Microwave introduction window

[0084] 12 Shower Panel

[0085] 13 Plasma treatment chamber

[0086] 14 Inner tube

[0087] 15 Gas supply unit

[0088] 16 Conductance control valve

[0089] 17 Turbomolecular pump

[0090] 18. Processed substrate

[0091] 19 Substrate carrier and high frequency electrode

[0092] 20 Bias power supply

[0093] 21 Automatic Matcher

[0094] 22 Base

[0095] 23 Stage cover

[0096] 24 Plasma

[0097] 25 Actuator

[0098] 26 Circular Polarization Wave Detector

[0099] 27 Electric field detector

[0100] 28 Control Department

[0101] 29 Insulation board

[0102] 30 Electric field vibration direction of TE11 mode

[0103] 34 Vibration direction of the electric field of microwave incident on the 180° phase difference plate

[0104] 35 Vibration direction of the electric field of microwaves passing through a 180° phase difference plate

[0105] 40 Electric field vibration direction of TE10 mode

[0106] 100, 100a: plasma processing device (etching device).

Claims

1. A plasma processing device, characterized in that: In a roughly cylindrical processing container, microwaves are provided as a matching device, a rectangular waveguide, and a connection between the rectangular waveguide and the circular waveguide. The circular waveguide is arranged symmetrically with respect to the processing container. A 90-degree phase difference plate and a 180-degree phase difference plate are provided in the circular waveguide.

2. The plasma processing device according to claim 1, characterized in that: The 180-degree phase difference plate is connected to a rotation driving mechanism.

3. The plasma processing device according to claim 1 or 2, characterized in that: A measuring unit for measuring the circumferential electric field in the circular waveguide is provided below the 180-degree phase difference plate.

4. The plasma processing device according to claim 3, characterized in that: The plasma processing apparatus further includes: a control unit that adjusts the angle of the 180-degree phase difference plate so as to minimize the circumferential deviation of the electric field measured by the measuring unit.

5. A plasma processing method, using the plasma processing device according to claim 3, characterized in that: The angle of the 180-degree phase difference plate is adjusted so as to minimize the circumferential deviation of the electric field measured by the measuring unit.

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