JP2005050776A - Electromagnetic field feeder and plasma device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that an electromagnetic field feeder and a plasma device using it become large in sizes as a whole and expensive in price. <P>SOLUTION: A rectangular/cylindrical circularly polarized wave converter 13 is used that is composed of a first rectangular waveguide part 31 in which one end is connected to the other end of the rectangular waveguide, an opening 14A which is formed on the first side wall of the first rectangular waveguide part 31 and to which one end of the cylindrical waveguide is connected, second and third rectangular waveguide parts 32, 33 in which one-side ends are connected to the second side wall and the third side wall of the first rectangular waveguide part 31 and in which other ends are short-circuited electric-functionally, and a protrusion 34 which is formed in the tube of the first rectangular waveguide part 31, which is protruded from the inner face of a fourth side wall opposed to the first side wall toward the opening 14A, and which has conductivity at least on the surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electromagnetic field supply device and a plasma device, and more particularly to an electromagnetic field supply device that supplies a high-frequency electromagnetic field via a rectangular waveguide and a cylindrical waveguide, and a plasma device using the same.

  In the manufacture of semiconductor elements and flat panel displays, plasma devices are frequently used to perform processing such as formation of insulating films, crystal growth of semiconductor layers, etching, and ashing. As one of the plasma apparatuses, there is a high-frequency plasma apparatus that generates plasma by ionizing, exciting, and dissociating a gas in a processing container by supplying a high-frequency electromagnetic field into the processing container using a slot antenna. Since this high-frequency plasma apparatus can generate high-density plasma at low pressure, efficient plasma processing is possible.

6 and 7 are diagrams showing a configuration example of a conventional electromagnetic field supply device that supplies a high-frequency electromagnetic field to a radial line slot antenna (hereinafter abbreviated as RLSA), which is one of the slot antennas.
A conventional electromagnetic field supply device 110A shown in FIG. 6 includes a high-frequency oscillator 111 that generates a high-frequency electromagnetic field, a rectangular waveguide 112 having one end connected to the high-frequency oscillator 111, and one end at the other end of the rectangular waveguide 112. There is connected a rectangular / cylindrical converter 113 for converting the transmission mode TE ₁₀ of rectangular waveguide to a transmission mode TE ₁₁ of the cylindrical waveguide, one end connected to the other end of the rectangular / cylindrical transducer 113, other A cylindrical waveguide 114 having an end connected to the RLSA 120 and a circular polarization converter 115 provided on the cylindrical waveguide 114 for converting linearly polarized waves into circularly polarized waves are provided.

As the circularly polarized wave converter 115, a structure in which a plurality of pairs of opposing cylindrical protrusions are provided on the inner wall of the cylindrical waveguide 114 at intervals of λ _g / 4 (λ _g is the wavelength in the tube) in the axial direction is used. . These columnar protrusions are arranged in a direction that forms 45 ° with respect to the main direction of the electric field vector of the TE ₁₁ mode high-frequency electromagnetic field introduced from the rectangular / cylindrical converter 113, so that the high-frequency electromagnetic field is converted into an electric field. The vector can be converted into a rotating electromagnetic field that rotates once in one cycle on a plane perpendicular to the axial direction.
By feeding circularly polarized waves to the RLSA 120 using such a circular polarization converter 115, the electric field intensity distribution in the RLSA 120 becomes a distribution that is symmetric with respect to the axis on a time average basis. Can be generated.

  However, some of the high-frequency electromagnetic fields are reflected inside the processing vessel or inside the RLSA 120 and propagate in the reverse direction through the cylindrical waveguide 114 and the rectangular / cylindrical converter 113. This reflected wave is reflected again at the other end of the rectangular waveguide 112 because the modes do not match, and as a result, the axial ratio of circularly polarized waves increases, and the electric field strength distribution (time average) in the RLSA 120 is axially symmetric. As a result, it is a cause of hindering uniform plasma generation. Here, the axial ratio means a value obtained by dividing the maximum value in the electric field intensity distribution on the circular cross section of the circularly polarized wave by the minimum value.

Therefore, as in the electromagnetic field supply device 110B shown in FIG. 7, a load matching unit 116 for circular polarization is provided between the RLSA 120 and the circular polarization converter 115, and the circular polarization converter 115 or the rectangular cylindrical converter is provided. Techniques have been proposed for reducing reflected waves propagating through 113 in the reverse direction. Although not shown, the circularly polarized load matching unit 116 is provided with a plurality of sets of opposing cylindrical protrusions on the inner wall of the cylindrical waveguide 114 at intervals of λ _g / 4 in the axial direction. Further, a plurality of opposing cylindrical protrusions provided at a position rotated 90 ° in the circumferential direction of the cylindrical waveguide 114 is used. By changing the length of the cylindrical protrusions protruding from the inner wall of the cylindrical waveguide 114 in the radial direction and adjusting the reactance of the cylindrical waveguide 114, the power supply side and the load side of the cylindrical waveguide 114 are adjusted. The reflected wave can be reduced by matching the impedance (see, for example, Patent Document 1).

However, the conventional electromagnetic field supply device 110A shown in FIG. 6 requires two parts, a rectangular / cylindrical converter 113 and a circularly polarized wave converter 115, for transmission mode and polarization conversion. Since a certain size or more is necessary to achieve this, there has been a problem that the electromagnetic field supply device 110A and the plasma device using the same increase in size as a whole.
In addition, the circularly polarized load matching unit 116 used in the conventional electromagnetic field supply device 110B shown in FIG. 7 is not a general-purpose product and is expensive. Therefore, the electromagnetic field supply device 110A and a plasma apparatus using the same are used. There was a problem of becoming expensive.

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
Japanese Patent Laid-Open No. 2003-110312

  Therefore, the problem to be solved by the present invention is that the electromagnetic field supply apparatus and the plasma apparatus using the same are increased in size and are expensive in price.

  In order to solve such problems, an electromagnetic field supply device of the present invention includes a high-frequency oscillator that generates a high-frequency electromagnetic field, a rectangular waveguide having one end connected to the high-frequency oscillator, A converter connected to the other end for converting the transmission mode of the rectangular waveguide to the transmission mode of the cylindrical waveguide and converting the linearly polarized wave to the circularly polarized wave, and the cylinder having one end connected to the converter And a converter formed on the first side wall of the first rectangular waveguide section, the first rectangular waveguide section having one end connected to the other end of the rectangular waveguide. And an opening to which one end of the cylindrical waveguide is connected, a second side wall sandwiching the first side wall of the first rectangular waveguide section, and a second side wall having a first end connected to the third side wall. And a third rectangular waveguide section and a fourth side disposed in the tube of the first rectangular waveguide section and facing the first side wall Projecting toward the inner surface in the opening, and characterized by comprising a protrusion having an electrically conductive at least on its surface.

  In the converter, the high-frequency electromagnetic field introduced from the rectangular waveguide to the first rectangular waveguide portion is reflected by the protrusions and branches into the cylindrical waveguide and the second and third rectangular waveguide portions. Will be introduced. The high-frequency electromagnetic field introduced into the second and third rectangular waveguide parts propagates through the rectangular waveguide part, is reflected at the end face, then propagates in the opposite direction, is again reflected by the protrusions, Introduced into a cylindrical waveguide. At this time, a high-frequency electromagnetic field directly introduced from the first rectangular waveguide portion into the cylindrical waveguide and the second rectangular waveguide portion from the first rectangular waveguide portion via the second or third rectangular waveguide portion. Since the direction of each electric field is spatially orthogonal to the high-frequency electromagnetic field introduced into the cylindrical waveguide, a circularly polarized wave is generated in the cylindrical waveguide by shifting the phase of each electric field. The Note that circular polarization with an axial ratio of 1 is generated by setting the magnitudes of the respective electric fields to the same and setting the phase difference to 90 °.

In this electromagnetic field supply device, the other end of the first rectangular waveguide portion may be electrically short-circuited. Or the rectangular waveguide of predetermined length may be connected to the other end of the 1st rectangular waveguide part, and the electromagnetic wave absorber may be arrange | positioned at the end surface of the rectangular waveguide.
The second and third rectangular waveguide portions may be short-circuited electrically at the other end.
The difference between the length of the second rectangular waveguide portion and the length of the third rectangular waveguide portion may be an odd multiple of approximately ¼ of the in-tube wavelength.
The protrusion has a three-dimensional shape having a circular cross section parallel to the fourth side wall of the first rectangular waveguide portion and a cross-sectional area that decreases from the bottom attached to the fourth side wall toward the top. You may be doing.
The above-described electromagnetic field supply apparatus may further include a load matching unit that is provided in the rectangular waveguide and that matches impedance between the power supply side and the load side of the rectangular waveguide.

  The plasma apparatus of the present invention includes a susceptor that is accommodated in a processing container and in which a target object is disposed, and a slot antenna that is disposed to face the susceptor and supplies a high-frequency electromagnetic field to or from the processing container. The electromagnetic field supply device described above is used to supply a high-frequency electromagnetic field to the slot antenna.

In the present invention, using a converter composed of the first to third rectangular waveguide sections and protrusions, the transmission mode is converted from the rectangular waveguide to the cylindrical waveguide, and the linearly polarized wave is converted into the circularly polarized wave. Convert to. This converter is smaller than the rectangular / cylindrical converter 113 and the circular polarization converter 115 having the same function. Therefore, the electromagnetic field supply apparatus and the plasma apparatus using the same can be reduced in size as compared with the conventional one.
In the present invention, the high-frequency electromagnetic field propagating in the reverse direction through the cylindrical waveguide is introduced into the rectangular waveguide without being reflected by the connection portion between the transducer and the rectangular waveguide. A load matcher can be provided in the waveguide. General-purpose products are commercially available as load matching units for rectangular waveguides and are inexpensive. By using such a load matching device, the price of the electromagnetic field supply device and the plasma device using the same can be reduced.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an overall configuration of a high-frequency plasma apparatus according to an embodiment of the present invention.
This plasma apparatus has a bottomed cylindrical processing container 1 having an open top. A susceptor 2 is accommodated inside the processing container 1. On the upper surface (mounting surface) of the susceptor 2, for example, a substrate W such as a semiconductor element, an LCD (liquid crystal display), or an organic EL (electro luminescent panel) is disposed as an object to be processed. A high frequency power source 4 is also connected to the susceptor 2 via a matching box 3.

An exhaust port 5 for vacuum exhaust is provided at the bottom of the processing container 1. A gas introduction nozzle 6 for introducing a gas into the processing container 1 is provided on the side wall of the processing container 1. For example, when the plasma apparatus is used as an etching apparatus, a plasma gas such as Ar and an etching gas such as CF ₄ are introduced from the nozzle 6.
The upper opening of the processing container 1 is closed with a dielectric plate 7 so as not to leak the plasma P generated inside the processing container 1 while introducing a high-frequency electromagnetic field therefrom. A sealing member 8 such as an O-ring is interposed between the upper surface of the side wall of the processing container 1 and the lower surface of the peripheral portion of the dielectric plate 7 to ensure airtightness in the processing container 1.

  An RLSA 20 that supplies a high-frequency electromagnetic field into the processing container 1 is disposed on the top of the dielectric plate 7. The RLSA 20 includes two circular conductor plates 22 and 24 that are parallel to each other to form a radial waveguide 21 and a conductor ring 23 that connects and shields the outer peripheral portions of the two conductor plates 22 and 24. Yes. An opening 25 connected to a cylindrical waveguide 14 of the electromagnetic field supply device 10 to be described later is formed in the central portion of the conductor plate 22 that becomes the upper surface of the radial waveguide 21, and a high frequency is supplied from the opening 25 to the radial waveguide 21. An electromagnetic field is introduced. A bump 27 protruding toward the opening 25 of the conductor plate 22 is provided at the central portion of the conductor plate 24 that is the lower surface of the radial waveguide 21. The bump 27 is formed in a substantially conical shape, and its tip is rounded. The conductor plate 24 is also formed with a plurality of slots 26 for supplying a high-frequency electromagnetic field propagating through the radial waveguide 21 into the processing container 1. These slots 26 constitute a slot antenna.

  The outer peripheries of the RLSA 20 and the dielectric plate 7 are covered with a shield material 9 arranged in an annular shape on the side wall of the processing vessel 1 so that the high frequency electromagnetic field supplied from the RLSA 20 to the inside of the processing vessel 1 does not leak to the outside. It has become.

  The electromagnetic field supply device 10 includes, for example, a high-frequency oscillator 11 that generates a high-frequency electromagnetic field having a predetermined frequency within a range of 0.9 GHz to several tens of GHz, a rectangular waveguide 12 having one end connected to the high-frequency oscillator 11, a rectangular shape A rectangular / cylindrical / circular polarization converter 13 connected to the other end of the waveguide 12, a cylindrical waveguide 14 having one end connected to the converter 13 and the other end connected to the RLSA 20, and a rectangular shape A load matching unit 16 is provided in the waveguide 12 or the cylindrical waveguide 14 and takes impedance matching between the power supply side and the load side.

FIG. 2 is a diagram illustrating a configuration of the rectangular / cylindrical / circular polarization converter 13. In this figure, (a) is a plan view, (b) is a sectional view taken along the line IIb-IIb 'in (a), and (c) is a side view of a part of the configuration. As shown in this figure, the rectangular / cylindrical / circular polarization converter 13 includes first to third rectangular waveguide portions 31 to 33 and a protrusion 34.
The first rectangular waveguide section 31 has one end connected to the other end of the rectangular waveguide 12 and the other end facing the one end is electrically short-circuited. An opening 14A to which one end of the cylindrical waveguide 14 is connected is formed in the wider side wall (first side wall) of the first rectangular waveguide part 31, and the narrower side sandwiching the first side wall is formed. One end of each of the second and third rectangular waveguide portions 32 and 33 is connected to the two side walls (second and third side walls).

The second and third rectangular waveguide sections 32 and 33 are arranged to form a T shape on the same plane when connected to the first rectangular waveguide section 31. You may arrange | position so that a cross may be made. That is, one axial line of the second and third rectangular waveguide portions 32 and 33 is on an extension line of the other axial line, and both axial lines are orthogonal to the axial line of the first rectangular waveguide portion 31. Be placed. The other ends of the second and third rectangular waveguide portions 32 and 33 are electrically short-circuited so as to reflect a high-frequency electromagnetic field. The lengths from one end to the other end of the second and third rectangular waveguide portions 32 and 33 are different from each other. The “length” means the length with respect to the guide wavelength. For example, the difference in length between the two is set to an odd multiple of about 1/4 of the in-tube wavelength λ _g of the rectangular waveguide sections 32 and 33 ((2N + 1) × 1/4 × λ _g (N is an integer of 0 or more)). ).

A protrusion 34 is disposed in the tube of the first rectangular waveguide portion 31. The bottom of the protrusion 34 is attached to a position facing the opening 14 </ b> A on the wider side wall (fourth side wall) facing the first side wall of the first rectangular waveguide part 31. As a result, the protrusion 34 protrudes from the inner surface of the fourth side wall of the first rectangular waveguide portion 31 toward the opening portion 14A.
The protrusion 34 has a three-dimensional shape in which the cross section parallel to the fourth side wall of the first rectangular waveguide portion is circular and the cross sectional area decreases from the bottom toward the top. For example, as shown in FIG. 2C, a combination of a bottom cylinder 34A having a large cross-sectional area perpendicular to the center line and a top cylinder 34B having a small cross-sectional area is used. Moreover, as shown in FIG. 3, you may use the cone shape by which the top part was rounded. The protrusion 34 is also formed of a metal such as aluminum. Since the protrusion 34 only needs to have conductivity on at least the surface, the protrusion 34 may be formed of a light material and covered with a metal film such as an aluminum foil.

An example of the dimensions of each part of the rectangular / cylindrical / circular polarization converter 13 for a frequency of 2.45 GHz is shown below.
First to third rectangular waveguide sections 31 to 33 have a width of 109.2 mm, a height of 54.6 mm,
Length of the second rectangular waveguide portion 32: 147.4 mm;
The length of the third rectangular waveguide portion 33: 110.4 mm.
In this example, the difference between the length of the length of the second rectangular waveguide portion 32 and a third rectangular waveguide section 33 is a 37 mm, and has a substantially 1/4 of the guide wavelength lambda _g.

FIG. 4 is a diagram for explaining the behavior of the high-frequency electromagnetic field introduced into the rectangular / cylindrical / circular polarization converter 13.
The linearly polarized high-frequency electromagnetic field 40 introduced from the rectangular waveguide 12 to the first rectangular waveguide portion 31 is reflected by the protrusion 34, and the cylindrical waveguide 14 and the second and third rectangular waveguides. It branches into the pipe parts 32 and 33 and is introduced. The high-frequency electromagnetic fields 42 and 43 introduced into the second and third rectangular waveguide portions 32 and 33 propagate through the rectangular waveguide portions 32 and 33, respectively, are reflected by the shorted end faces, and then reverse Propagating in the direction, reflected again by the protrusion 34, and introduced into the cylindrical waveguide 14.

The difference between the length of the second rectangular waveguide portion 32 and the length of the third rectangular waveguide portion 33 is set to approximately ¼ of the in-tube wavelength λ _g , whereby the second rectangular waveguide portion. path length difference between the high-frequency electromagnetic field propagating a high-frequency electromagnetic field and a third rectangular waveguide 33 to propagate 32 becomes substantially 1/2 of the guide wavelength lambda _g. As a result, both high-frequency electromagnetic fields have the same phase on the opening 14A and are introduced into the cylindrical waveguide 14 without being canceled out.

Further, the electric field E1 of the high-frequency electromagnetic field 41 introduced directly from the first rectangular waveguide portion 31 to the cylindrical waveguide 14 and the second or third rectangular waveguide from the first rectangular waveguide portion 31. The direction is spatially orthogonal to the combined electric field E2 of the high-frequency electromagnetic fields 42 and 43 introduced into the cylindrical waveguide 14 via the tube portions 32 and 33. Therefore, as described above, the rectangular / cylindrical / circular polarization converter 13 is configured, and the lengths of the second and third rectangular waveguide portions 32 and 33 are adjusted, so that the phase difference between the electric fields E1 and E2 is changed. By making the angle 90 degrees and making the magnitudes of both electric fields the same, a circularly polarized wave having an axial ratio of 1 is generated in the cylindrical waveguide 14.
Thus, by using a rectangular / cylindrical-circular polarization converter 13, converts the transmission mode TE ₁₀ of rectangular waveguide to the transmission mode TE ₁₁ of the cylindrical waveguide, circular polarization and linear polarization Can be converted to

  By using this rectangular / cylindrical / circular polarization converter 13 in the electromagnetic field supply device 10, the rectangular / cylindrical / circular polarization converter 13 converts the linearly polarized high-frequency electromagnetic field generated by the high-frequency oscillator 11 into a circular polarization. It can be converted into a wave and circularly polarized power can be fed to the RLSA 20. As a result, the electric field strength distribution of the radial waveguide 21 of the RLSA 20 is a time-averaged distribution that is symmetric with respect to the axis of the radial waveguide 21. Therefore, a high-frequency electromagnetic field having a symmetric distribution with respect to the axis of the processing container 1 is supplied into the processing container 1 from the plurality of slots 26 formed on the lower surface 24 of the radial waveguide 21 in the time average. Due to the high frequency electromagnetic field, the gas introduced into the processing container 1 is ionized, excited or dissociated to generate the plasma P, so that the plasma P has a time-averaged axially symmetric distribution. By processing the substrate W on the susceptor 2 using this plasma P, uniform processing can be performed on the entire area of the substrate W.

  In addition, the rectangular / cylindrical / circular polarization converter 13 can realize the same functions as those of the rectangular / cylindrical converter 113 and the circular polarization converter 115 that have been used conventionally, with a smaller configuration. Therefore, by using the rectangular / cylindrical / circular polarization converter 13, the electromagnetic field supply apparatus 10 and the plasma apparatus using the same can be reduced in size as compared with the conventional one.

  When the rectangular / cylindrical / circular polarization converter 13 is used, the reflected wave reflected in the processing container 1 or the radial waveguide 21 of the RLSA 20 and propagating in the reverse direction in the cylindrical waveguide 14 is rectangular / Since it is introduced into the rectangular waveguide 12 without being reflected at the connection between the cylindrical / circular polarization converter 13 and the rectangular waveguide 12, a load is applied to the rectangular waveguide 12 as shown in FIG. A matcher 16 can be provided. General-purpose products are commercially available as load matching units for rectangular waveguides and are inexpensive. Therefore, by using the rectangular / cylindrical / circular polarization converter 13 and using an inexpensive rectangular waveguide load matching device, the price of the electromagnetic field supply device 10 and the plasma device using the same can be reduced. .

  In the rectangular / cylindrical / circular polarization converter 13, the second and third rectangular waveguide portions 32 and 33 are connected to one end connected to the first rectangular waveguide portion 31 as shown in FIG. 5. You may make it the other end which opposes slide freely to the axial direction of the rectangular waveguide parts 32 and 33 by the contact type or non-contact type short plunger (movable short circuit) 32A and 33A. The rectangular waveguide portions 32 and 33 may be formed of bellows rectangular waveguides (flexible rectangular waveguides) having bellows whose length in the axial direction can be expanded and contracted on the side walls. Thereby, the length from one end to the other end of the rectangular waveguide portions 32 and 33 can be finely adjusted.

  Further, for example, about 4 to 16 detectors are arranged in the circumferential direction in the middle of the cylindrical waveguide 14, the axial ratio of the circularly polarized waves is measured, and the short plungers 32A and 33A are measured based on the measurement result. The position may be adjusted manually or automatically using a control device. Thereby, the axial ratio of circularly polarized waves can be improved. The axial ratio of circular polarization is preferably a value close to 1. However, the axial ratio of circular polarization may be larger than 1.

The other ends of the second and third rectangular waveguide portions 32 and 33 may have a structure in which the high-frequency electromagnetic field introduced from one end is reflected there. Therefore, the other end does not necessarily have to be short-circuited in terms of electrical function, and may be in an open state, for example, at a high frequency. That is, the inside and the outside of the rectangular waveguide portions 32 and 33 may communicate with each other through the other end, and the other end may be closed with a dielectric.
Further, the electromagnetic field supply apparatus 10 using the rectangular / cylindrical / circular polarization converter 13 can be used not only for the high-frequency plasma apparatus shown in FIG. 1 but also for the microwave supply of the ECR plasma apparatus.

1 is a diagram illustrating an overall configuration of a high-frequency plasma apparatus according to an embodiment of the present invention. It is a figure which shows the structure of a rectangle / cylinder and a circularly polarized wave converter. It is a perspective view which shows the other structural example of the protrusion of a rectangular / cylindrical / circular polarization converter. It is a figure for demonstrating the behavior of the high frequency electromagnetic field introduced into the rectangular / cylindrical / circular polarization converter. It is a figure for demonstrating the modification of a rectangle / cylinder and a circularly polarized wave converter. It is a figure which shows one structural example of the conventional electromagnetic field supply apparatus. It is a figure which shows the other structural example of the conventional electromagnetic field supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Processing container, 2 ... Susceptor, 3 ... Matching box, 4 ... High frequency power supply, 5 ... Exhaust port, 6 ... Gas introduction nozzle, 7 ... Dielectric plate, 8 ... Sealing member, 9 ... Shielding material, 10 ... Electromagnetic Field supply device, 11 ... high frequency oscillator, 12 ... rectangular waveguide, 13 ... rectangular / cylindrical circular polarization converter, 14 ... cylindrical waveguide, 14A ... opening, 16 ... load matching device, 20 ... RLSA (radial) (Line slot antenna), 21 ... radial waveguide, 22,24 ... circular conductor plate, 23 ... conductor ring, 25 ... opening, 26 ... slot, 27 ... bump, 31 ... first rectangular waveguide section, 32 ... first 2 rectangular waveguide portions, 32A ... short plunger (movable short circuit), 33 ... third rectangular waveguide portion, 33A ... short plunger (movable short circuit), 34 ... projection, 34A ... bottom cylinder, 34B ... Top cylinder, 40-43 High-frequency electromagnetic field, E1, E2 ... electric field, P ... plasma, W ... board (object to be processed).

Claims (7)

A high-frequency oscillator that generates a high-frequency electromagnetic field;
A rectangular waveguide having one end connected to the high-frequency oscillator;
A converter that is connected to the other end of the rectangular waveguide, converts the transmission mode of the rectangular waveguide to the transmission mode of the cylindrical waveguide, and converts linearly polarized waves into circularly polarized waves;
A cylindrical waveguide having one end connected to the transducer;
The converter is
A first rectangular waveguide section having one end connected to the other end of the rectangular waveguide;
An opening formed on a first side wall of the first rectangular waveguide portion and connected to the one end of the cylindrical waveguide;
Second and third rectangular waveguide portions each having one end connected to a second sidewall and a third sidewall sandwiching the first sidewall of the first rectangular waveguide portion;
A protrusion disposed in the tube of the first rectangular waveguide section, protruding from the inner surface of the fourth side wall facing the first side wall toward the opening, and having at least a conductive surface. An electromagnetic field supply device comprising the electromagnetic field supply device. The electromagnetic field supply apparatus according to claim 1,
The electromagnetic field supply apparatus according to claim 1, wherein the other end of the first rectangular waveguide section is electrically short-circuited. In the electromagnetic field supply device according to claim 1 or 2,
The electromagnetic field supply device according to claim 2, wherein each of the second and third rectangular waveguide sections is electrically short-circuited at the other end. In the electromagnetic field supply device according to any one of claims 1 to 3,
The electromagnetic field supply apparatus according to claim 1, wherein a difference between the length of the second rectangular waveguide portion and the length of the third rectangular waveguide portion is an odd multiple of approximately ¼ of an in-tube wavelength. In the electromagnetic field supply device according to any one of claims 1 to 4,
The protrusion has a circular cross section parallel to the fourth side wall of the first rectangular waveguide portion, and the cross-sectional area decreases from the bottom attached to the fourth side wall toward the top. An electromagnetic field supply device having a three-dimensional shape. In the electromagnetic field supply device according to any one of claims 1 to 5,
An electromagnetic field supply device, comprising: a load matching unit provided in the rectangular waveguide for matching impedance between a power supply side and a load side of the rectangular waveguide. A susceptor housed inside the processing container and in which the object to be processed is disposed, a slot antenna disposed opposite to the susceptor and supplying a high frequency electromagnetic field to the inside of the processing container, and a high frequency electromagnetic field supplied to the slot antenna In a plasma apparatus comprising an electromagnetic field supply device
The said electromagnetic field supply apparatus is an electromagnetic field supply apparatus described in any one of Claims 1-6, The plasma apparatus characterized by the above-mentioned.

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