Plasma Processing Equipment

Abstract

In order to make it possible to improve the uniformity of plasma within a processing chamber of a plasma processing device, this plasma processing device comprises: a sample chamber 0112 that comprises, in the interior thereof, a sample stage where a substrate 0113 under processing is placed; a magnetic field production means 0116 that produces a magnetic field in the interior of the sample chamber; a microwave power source 0101 that produces microwave power; microwave power conveyance parts 0103, 0106 that convey the microwave power; and a microwave three-dimensional circuit part that supplies the conveyed microwave power to the interior of a processing chamber via a dielectric window, wherein the microwave three-dimensional circuit part is configured comprising a branch circuit 0202 that causes the microwave power which was conveyed by the microwave power conveyance parts to branch in a plurality of azimuth angle directions, a ring resonator 0201 that causes the microwave power, which the branch circuit has caused to branch in the plurality of azimuth angle directions, to resonate, and a coaxial passage part 0110 that supplies the microwave power, which the ring resonator has cause to resonate, into the interior of the processing chamber via the dielectric window.

Description

[Technical field]

[0001] The present invention relates to a plasma processing apparatus that generates plasma by using the interaction between microwaves and a static magnetic field, and more particularly to an apparatus that configures a static magnetic field and a microwave three-dimensional circuit system so that the propagation direction of the microwave in a plasma processing chamber is approximately perpendicular to the direction of the static magnetic field and the direction of the microwave electric field is approximately perpendicular to the direction of the static magnetic field, and that optimizes the microwave three-dimensional circuit system from the viewpoint of plasma density distribution in the processing chamber. [Background technology]

[0002] Plasma processing equipment is used in the production of semiconductor integrated circuit elements. The miniaturization of elements has progressed to improve element performance and reduce costs. Previously, two-dimensional miniaturization of elements increased the number of elements that could be manufactured from a single substrate, reducing the manufacturing cost per element, while improving performance through miniaturization effects such as shortening wiring length. However, as the dimensions of semiconductor elements reach the nanometer order, which is close to the dimensions of atoms, the difficulty of two-dimensional miniaturization increases significantly, and measures such as the application of new materials and three-dimensional element structures are being taken. These structural changes have increased the difficulty of manufacturing and the number of manufacturing processes, making the increase in manufacturing costs a serious problem.

[0003] If minute foreign objects or contaminants adhere to semiconductor integrated circuit elements during manufacturing, it can cause fatal defects, so semiconductor integrated circuit elements are manufactured in clean rooms where foreign objects and contaminants are eliminated and temperature and humidity are optimally controlled. As elements become finer, the cleanliness of the clean rooms required for manufacturing becomes higher, and the construction and maintenance of clean rooms requires huge costs. For this reason, there is a demand for efficient use of clean room space in production. From this perspective, there is a strong demand for miniaturization and cost reduction in semiconductor manufacturing equipment.

[0004] The in-plane uniformity of the plasma processing on the substrate to be processed is also important. In the manufacture of semiconductor integrated circuit elements, disk-shaped silicon wafers with a diameter of 300 mm are often used as the substrate to be processed. Many semiconductor integrated circuit elements are often created on these silicon wafers, but if the in-plane uniformity of the plasma processing is poor, the number of good products that meet the specifications that can be obtained from a single silicon wafer may be reduced. Similarly, the stability of the plasma processing for each substrate to be processed is also important. If the quality of the plasma processing is not stable, for example if the quality changes over time, the proportion of good products may similarly decrease.

[0005] Among plasma processing devices that generate plasma by electromagnetic waves, devices that use microwaves with a frequency of about several GHz, typically 2.45 GHz, are widely used. In particular, there is a device that uses the Electron Cyclotron Resonance (hereinafter referred to as ECR) phenomenon that occurs when microwaves are combined with a static magnetic field, and this device has excellent features such as being able to generate plasma relatively stably even under conditions where plasma generation is usually difficult, such as extremely low pressure, and being able to control the distribution of plasma by the distribution of the static magnetic field.

[0006] A phenomenon known as the interaction between microwaves and a static magnetic field is Upper Hybrid Resonance (UHR). This is a phenomenon in which microwaves (called X-waves) that propagate in a direction perpendicular to the static magnetic field and whose microwave electric field is perpendicular to the static magnetic field resonate with electrons in the plasma, causing the microwave energy to be strongly absorbed by the electrons. It is known that UHR occurs with a static magnetic field that is weaker than ECR. There are few publicly known examples of plasma processing equipment that actively utilizes this phenomenon, but the following inventions are examples of conventional technology. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-110047 A Summary of the Invention [Problem to be solved by the invention]

[0008] In Patent Document 1, a static magnetic field is applied approximately parallel to the central axis of a substantially cylindrical processing chamber, and microwaves are input from the side. Furthermore, the electric field of the microwaves is approximately perpendicular to the central axis of the processing chamber. These measures excite X-waves in the plasma in the processing chamber, and UHR is utilized. Furthermore, an electrode for placing a substrate to be processed is provided on one side of the processing chamber that is approximately perpendicular to the static magnetic field, and an earth electrode (called an opposing earth) is provided on the other side. This allows the RF bias described below to be efficiently applied to the substrate to be processed. Compared to devices using ECR, resonance can be caused by a weak static magnetic field, so there are advantages such as reduced power consumption by electromagnets for generating a static magnetic field, and the electromagnets can be made smaller, increasing the freedom of placement.

[0009] Furthermore, in Patent Document 1, the opposing earth is supported by multiple pillars, and microwaves are efficiently input into the processing chamber by a three-dimensional microwave circuit system that includes a structure for suppressing microwave reflection caused by discontinuous parts such as these pillars.

[0010] In plasma processing equipment using microwaves, magnetrons are widely used as microwave oscillators, but recently oscillators using solid-state elements have also come into use. Oscillators using solid-state elements have the advantage that the oscillation frequency and output are more stable than magnetrons, and various modulations can be easily applied. In addition, rectangular waveguides, circular waveguides, coaxial lines, etc. are used to transmit microwave power. In addition, isolators to protect the microwave oscillator and automatic matching devices to prevent impedance mismatch with the load are often used in combination.

[0011] In addition, the quality of plasma processing can be improved by applying RF bias power to the substrate to be processed. For example, in the case of plasma etching, a DC bias voltage caused by the mass difference between ions and electrons is generated in the substrate to be processed by RF bias with a frequency of about 400 kHz to 13.56 MHz, and this DC bias voltage attracts ions in the plasma, thereby improving the verticality of the processed shape and the processing speed, thereby improving the quality of plasma processing.

[0012] Generally, when there is a discontinuity in the transmission path of microwaves, reflected waves are generated. In the structure for injecting microwaves into a plasma processing chamber, for example, when a circular waveguide is expanded in a step-like manner, reflected waves are generated due to this. If the structure for realizing the optimal electromagnetic field distribution in the plasma processing chamber from the viewpoint of plasma uniformity becomes complicated, microwave power may not be efficiently transmitted into the processing chamber due to the influence of reflected waves generated at each part. Therefore, it is desirable to simplify the structure as much as possible, but it is often difficult to achieve a desirable electromagnetic field. As a countermeasure, the above-mentioned matching box is used, but if the degree of mismatch with the load is too large, it may be difficult to secure a wide matching range corresponding to this, and a large standing wave may occur between the matching box and the load, which may cause abnormal discharge and power loss.

[0013] It was found that when the embodiment disclosed in Patent Document 1 is applied, depending on the plasma generation conditions, the plasma may be excessively localized near the side wall of the processing chamber, resulting in a low plasma density near the substrate to be processed. The inventors investigated the cause of this and found that the proportion of the intended microwave propagation mode is low, and the proportion of higher modes with multiple changes in the azimuth angle may be high. The intended microwave propagation mode had a number of changes in the azimuth angle (referred to as m) of 1, but it was found that high-order modes such as m=5 may occur frequently due to the influence of multiple supports used to hold the opposing earth.

[0014] In order to further improve the uniformity of plasma density inside the plasma processing chamber, it is necessary to increase the proportion of the m=1 mode and reduce the proportion of higher modes with larger m by devising a structure for the microwave three-dimensional circuit.

[0015] The present invention provides a plasma processing apparatus that solves the above-mentioned problems of the conventional technology and makes it possible to further improve the uniformity of plasma in a processing chamber. [Means for solving the problem]

[0016] In order to solve the above problems, the present invention provides The apparatus includes a processing chamber in which a substrate to be processed is subjected to plasma processing, a high-frequency power source which supplies high-frequency microwave power for generating plasma via a waveguide, a magnetic field forming means which forms a magnetic field within the processing chamber, a sample stage on which the substrate to be processed is placed, a circular waveguide which transmits the microwaves transmitted from the waveguide to a plurality of rectangular waveguides, a ring-shaped resonator which resonates the microwaves transmitted from the plurality of rectangular waveguides, an earth disposed below the plurality of rectangular waveguides, a cylindrical dielectric window disposed below the earth, and a coaxial line section which supplies the high-frequency power resonated by the resonator to the processing chamber via the dielectric window. Configured. Effect of the Invention

[0017] According to the present invention, by using the microwave three-dimensional circuit of the above configuration, it becomes possible to excite microwaves of m=1 in the coaxial line and in the plasma processing chamber, and it becomes possible to further improve the uniformity of the plasma in the processing chamber compared to the conventional technology. [Brief description of the drawings]

[0018] [Figure 1] 1 is a front cross-sectional view showing a schematic configuration of a microwave plasma etching apparatus according to a conventional technology. [Diagram 2] 1 is a front cross-sectional view showing a schematic configuration of a microwave plasma etching apparatus according to an embodiment of the present invention. [Figure 3A] 1 is a vertical cross-sectional view showing a microwave three-dimensional circuit of a microwave plasma etching apparatus according to an embodiment of the present invention. [Figure 3B] 1 is a plan view of a microwave three-dimensional circuit of a microwave plasma etching apparatus according to an embodiment of the present invention. [Figure 4A] 3 is a front cross-sectional view of a ring resonator showing an electric field distribution in the ring resonator of the microwave plasma etching apparatus according to the embodiment of the present invention. FIG. [Figure 4B]4B is a cross-sectional view of the ring resonator taken along the arrows MM in FIG. 4A, illustrating an electric field distribution in the ring resonator of the microwave plasma etching apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention relates to a plasma processing apparatus that has a substantially cylindrical plasma processing chamber and generates plasma by inputting microwave power from the side of the plasma processing chamber. The apparatus has a problem that the proportion of microwave power that travels in the radial direction of the microwaves is small, and the generated plasma is excessively localized near the inner wall of the side, resulting in low plasma density near the central axis of the plasma processing chamber. This problem is solved by a configuration in which microwaves are input into the processing chamber using a ring resonator that resonates in a mode with an azimuthal direction dependency m value of 1 in order to suppress the azimuthal propagation of the microwaves and increase the radial propagation component, thereby realizing a plasma processing apparatus that makes it possible to further improve the uniformity of plasma in the plasma processing chamber.

[0020] In addition, in the plasma processing apparatus of the conventional technology described above, depending on the plasma generation conditions, the plasma may be excessively localized near the side wall of the processing chamber, resulting in a low plasma density near the substrate to be processed. In response to this, the present invention has made it possible to increase the proportion of the m=1 mode by devising a structure for the microwave three-dimensional circuit, thereby making it possible to reduce the proportion of higher modes with a large m. As a result, the present invention has realized a plasma processing apparatus that solves the problems in the conventional technology and makes it possible to further improve the uniformity of the plasma in the processing chamber.

[0021] The configuration of a plasma processing apparatus according to the prior art disclosed in the embodiment of Patent Document 1 will be described with reference to FIG. 1. This prior art is a plasma processing apparatus 100 for performing an etching process. A microwave having a frequency of 2.45 GHz generated by a microwave source 0101 is transmitted to a circular waveguide 0106 via an isolator and an automatic matching device 0102 (not shown), a rectangular waveguide 0103, and a circular-to-rectangle converter 0104 that also serves as a corner for changing the transmission direction by 90 degrees. A circular polarized wave generator 0105 is loaded in the circular waveguide 0106. The circular polarized wave generator 0105 has a function of converting a microwave incident as a linearly polarized wave into a circularly polarized wave. By circularly polarizing the microwave, it is possible to generate a plasma that is uniform in the azimuth direction. The microwave is further transmitted to a coaxial line 0110 via an enlarged portion 0107. The microwave electric field distribution in the coaxial line 0110 is typically indicated by arrows.

[0022] Below the expanded portion 0107 is an opposing earth 0109 fixed to the outside via multiple supports 0108. Below the opposing earth 0109, inside the coaxial line 0110, is a cylindrical microwave introduction window 0111. The material of the microwave introduction window should desirably have low microwave loss, be plasma resistant, and be unlikely to adversely affect the plasma processing, and quartz is used.

[0023] A ring-shaped alignment member 0119 is disposed on the inner periphery of the expanded portion 0107 at a portion where it contacts the ceiling wall and the side wall.

[0024] The area surrounding the opposing earth 0109 and the microwave introduction window 0111 constitutes the plasma processing chamber 0112. Inside the plasma processing chamber, there is a substrate electrode 0114 on which a substrate 0113 to be processed having a diameter of 300 mm is placed. An RF power supply 0115 is connected to the substrate electrode 0114 via an automatic matching box 0117, and an RF bias can be applied to the substrate 0113 to be processed. The RF power supply 0115 has an oscillation frequency of 400 kHz. Furthermore, a multi-stage solenoid coil 0116 equipped with a yoke is provided around these mechanisms, and a static magnetic field can be applied inside the plasma processing chamber 0112.

[0025] The substrate 0113 to be processed is disk-shaped, and the apparatus is basically axially symmetrical with the central axis of the substrate 0113 to be processed. That is, the base electrode 0114, the coaxial line 0110, the opposing earth 0109, the enlarged portion 0107, the circular waveguide 0106, and the solenoid coil 0116 are arranged coaxially with the central axis of the approximately cylindrical plasma processing chamber 0112.

[0026] In addition, a gas supply system and a vacuum exhaust system (not shown) are connected to the plasma processing chamber 0112, and a processing gas can be supplied and exhausted at a predetermined flow rate while maintaining a predetermined pressure.

[0027] The opposing earth 0109 needs to be fixed to the external structure, and also has a built-in temperature adjustment mechanism for cooling, etc., and a gas supply mechanism from the opposing earth part, and is fixed to the outside with multiple supports 0108. Flow paths for the coolant and gas are provided inside the supports 0108. Furthermore, the opposing earth 0109 is electrically connected to the outside by the supports 0108, which stabilizes the potential.

[0028] 1, it was found that the plasma generated in the plasma processing chamber 0112 was excessively localized mainly near the inner surface of the microwave introduction window 0111, and the density near the central axis of the processing chamber was sometimes low. As a result, the processing speed of the plasma etching process performed on the substrate 0113 to be processed was sometimes slow.

[0029] The inventors investigated the cause of this and found that it was because the input microwaves mainly traveled in the azimuth direction, with a small proportion of components traveling in the radial direction. Furthermore, it was found that the main reason the microwaves travel in the azimuth direction is due to the multiple supports 0108 that hold the opposing earth 0109. The supports 0108 support the opposing earth 0109 from the sides in the radial direction, and it was found that this influence excites a component with a large azimuth-direction dependency m.

[0030] Generally, microwaves propagate as plane waves in a boundaryless vacuum at the speed of light, and the wavelength in the direction of wave travel is the speed of light divided by the frequency. When a perfect conductor surface is present in space, microwaves are reflected so as to satisfy the boundary condition that the electric field vector is perpendicular to the perfect conductor surface. In a three-dimensional microwave circuit system composed of a waveguide, etc., the inner wall of the waveguide can be analyzed as a perfect conductor, and the electromagnetic field distribution is determined by the superposition of each wave as it repeatedly reflects off the inner wall to satisfy the boundary condition.

[0031] In the ring resonator, the microwave electromagnetic field inside is determined by repeated reflections on the inner walls in the same way as above. The direction of wave propagation can be evaluated by a wave vector, which can be considered in a cylindrical coordinate system (r, θ, z), and has components in the radial (r), azimuth (θ), and height (z) directions. 110 In a mode ring resonator, the wave vector has a z-component of zero, and propagates in the radial and azimuth directions, but not in the height direction. The azimuth dependence m indicates that there are m wavelengths of waves in one azimuth revolution (360 degrees), and when m=1, there is a change of one period in the azimuth direction.

[0032] Based on the above considerations, we have studied the structure of a microwave three-dimensional circuit that excites a component with a small azimuth-angle dependence m in the processing chamber. However, considering that the lowest mode of the circular waveguide 0106 used to input microwaves into the plasma processing chamber 0112 is m=1, we have studied a structure that excites a microwave electromagnetic field with m=1 in the processing chamber.

[0033] The configuration of a plasma processing apparatus 200 according to this embodiment based on the results of this study is shown in FIG. 2, and a partial detailed configuration thereof will be described with reference to FIGS. 3A to 4B.

[0034] The configuration of the plasma processing apparatus 200 according to this embodiment shown in Fig. 2 differs from the conventional plasma processing apparatus 100 shown in Fig. 1 in that it includes a branch circuit 0202 for inputting microwave power to the plasma processing chamber 0112, a ring resonator 0201, a coaxial line 0110, and a facing earth 0203 having a convex portion 0204 formed in the center. The matching rod 0302, matching ridge 0303, and phase adjustment means 0304 that form the branch circuit 0202 will be described with reference to Figs. 3A and 3B. Other components with the same part numbers as those in Fig. 1 are the same as those in the conventional plasma processing apparatus 100 described in Fig. 1, and descriptions of the components common to this embodiment will be omitted.

[0035] 2, microwaves circularly polarized by the circular polarizer 0105 and transmitted through the circular waveguide 0106 are branched by a branch circuit 0202 formed on the upper surface 0204 of the convex portion of the counter earth 0203 directly below the circular waveguide 0106, and excite a ring resonator 0201 formed around the side surface 0205 of the convex portion of the counter earth 0203. A coaxial line 0110 is further connected to the ring resonator 0201, and the microwaves are input into the plasma processing chamber 0112 through a microwave introduction window 0111.

[0036] The branch circuit 0202 and its surroundings will be described in detail with reference to Figures 3A and 3B. Figure 3A is a side cross-sectional view, and Figure 3B is a plan view. The branch circuit 0202 has a role of transmitting microwaves transmitted from the circular waveguide 0106 to the ring resonator 0201, and is composed of a rectangular waveguide 0301 branched into six by a phase adjustment means 0304, a matching rod (first matching section) 0302 that suppresses reflected waves at the branching section between the circular waveguide 0106 and the rectangular waveguide 0301, and a matching ridge (second matching section) 0303 that suppresses reflections from the connection surface with the ring resonator 0201, etc.

[0037] The rectangular waveguide 0301 is arranged by being branched at equal intervals of 60 degrees in the azimuth direction by six phase adjustment means 0304, and the microwave power is branched in six directions, but the number of branches may be an integer of 3 or more. 10 The dimensions are designed to operate in mode.

[0038] The matching rod 0302 has a cylindrical shape arranged coaxially with the circular waveguide 0106, and by optimizing its diameter and height, it is possible to suppress reflected waves at the connection surfaces between the circular waveguide 0106 and the multiple rectangular waveguides 0301. Similarly, the matching ridge 0303 can suppress reflected waves caused by discontinuous surfaces after the rectangular waveguide 0301 by adjusting its position, height, and width.

[0039] By optimally adjusting the shape parameters of the matching rod 0302 and the matching ridge 0303, it is possible to efficiently transmit the microwave power incident from the circular waveguide 0106 to the inside of the processing chamber. However, if microwave reflection is tolerable, the matching rod 0302 and the matching ridge 0303 may be omitted.

[0040] In addition, a microwave introduction window 0111 as described in Figure 2 is attached to the inner side of the coaxial line 0110 connected to the ring resonator 0201, and the bottom surface of the coaxial line 0110 is closed. However, in Figure 3A, the microwave introduction window 0111 is omitted, and the bottom surface of the coaxial line 0110 is shown in an open state.

[0041] Generally, only electromagnetic fields that satisfy the boundary conditions can exist inside a resonator. Therefore, a desired electromagnetic field can be obtained by using a resonator that resonates with the desired electromagnetic field. In this embodiment, the electric field distribution (TM 110 A ring resonator 0201 that resonates in a certain mode (called m mode) is used. This makes it possible to obtain an electromagnetic field that satisfies the desired m=1.

[0042] FIG. 4A shows a longitudinal section, and FIG. 4B shows an MM cross-sectional view of FIG. 4A. 110 The mode is the lowest TE10 The mode can be considered as a ring-shaped bend of a rectangular waveguide with a length of one wavelength operating in the mode.

[0043] As shown in Figure 4B, the electric field vector also changes in one revolution in the azimuth direction, resulting in mode m = 1. The wave vector, which indicates the direction of wave travel, only has azimuth and radial components, and does not have a component parallel to the central axis.

[0044] Therefore, TM 110 The resonance condition of the mode ring resonator does not depend on the dimension parallel to the central axis (H in FIG. 4A), but only on the inner radius (a in FIG. 4A) and the outer radius (b in FIG. 4A) of the ring. Since a circularly polarized wave is supplied to the circular waveguide, the electromagnetic field in the ring resonator 0201 shown in FIG. 4A and FIG. 4B rotates in time in the azimuth direction.

[0045] TM 110 Taking into account the boundary conditions, a ring resonator that resonates in the mode satisfies the following equation (Equation 1): The dimensions of the ring resonator can be found by solving this equation (Equation 1).

[0046]

number

[0047] A coaxial line 0110 is connected to the bottom of the ring resonator 0201, and the coaxial line 0110 is excited by microwaves adjusted to the m=1 mode in the ring resonator 0201. In the configuration disclosed in the above-mentioned Patent Document 1, there are multiple supports near the microwave entrance surface of the coaxial line section to maintain the opposing earth, which causes a large m wave. In this embodiment, there is no structure that is discontinuous in the azimuth direction on the path from the coaxial line to the plasma processing chamber, and the m=1 distribution in the ring resonator is maintained to excite the coaxial line. There is also no structure that is discontinuous in the azimuth direction inside the plasma processing chamber, and microwaves can be introduced into the processing chamber with a distribution of m=1 through the microwave introduction window.

[0048] According to this embodiment, by using the microwave three-dimensional circuit having the configuration described above, it becomes possible to excite microwaves of m=1 in the coaxial line and in the plasma processing chamber, so that it becomes possible to further improve the uniformity of the plasma density inside the plasma processing chamber.

[0049] The invention made by the present inventor has been specifically described above based on the embodiments, but it goes without saying that the present invention is not limited to the above embodiments and can be modified in various ways without departing from the gist of the invention. For example, the above embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the configurations described. In addition, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0050] 0101...microwave source, 0102...automatic matching box, 0103...rectangular waveguide, 0104...circular-to-rectangular converter, 0105...circularly polarized wave generator, 0106...circular waveguide, 0107...expansion section, 0108...support, 0109...counter earth, 0110...coaxial line, 0111...microwave introduction window, 0112...plasma processing chamber, 0113...substrate to be processed, 0114...substrate electrode, 0115...RF power supply, 0116...solenoid coil, 0201...ring resonator, 0202...branch circuit, 0203...counter earth, 0204...convex section, 0301...six-branched rectangular waveguide, 0302...matching rod, 0303...matching ridge, 0304...phase adjustment means.

Claims

1. a processing chamber in which a substrate to be processed is subjected to plasma processing; a high frequency power source that supplies high frequency microwave power for generating plasma via a waveguide; a magnetic field forming means for forming a magnetic field within the processing chamber; a sample stage on which the substrate to be processed is placed; a circular waveguide that transmits the microwaves transmitted from the waveguide to a plurality of rectangular waveguides; a ring-shaped resonator that resonates the microwaves transmitted from the plurality of rectangular waveguides; a ground disposed below the plurality of rectangular waveguides; a cylindrical dielectric window disposed below the earth; a coaxial line section for supplying the high frequency power resonated by the resonator to the processing chamber through the dielectric window.

2. 2. The plasma processing apparatus according to claim 1, The earth has a protruding portion, The plasma processing apparatus according to claim 1, wherein the resonator is disposed so as to surround the protrusion.

3. 2. The plasma processing apparatus according to claim 1, 2. A plasma processing apparatus comprising: a first phase adjusting means for adjusting a phase of a first rectangular waveguide;

4. 2. The plasma processing apparatus according to claim 1, a first matching section for suppressing reflected waves at a connection between the circular waveguide and the plurality of rectangular waveguides, and a second matching section for suppressing reflected waves caused by discontinuous surfaces in a transmission path from the plurality of rectangular waveguides to the processing chamber.

5. 2. The plasma processing apparatus according to claim 1, The plasma processing apparatus, wherein the resonator resonates the microwaves transmitted from the plurality of rectangular waveguides with an electric field distribution of a TM 110 mode.

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