JP3774142B2 - Plasma generator and plasma processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma generation apparatus and a plasma processing apparatus, and more particularly to a plasma generation apparatus capable of forming plasma having an arbitrary distribution inside a vacuum chamber and a plasma processing apparatus such as an etching apparatus equipped with the plasma generation apparatus.
[0002]
[Prior art]
Plasma processing such as dry etching, ashing, thin film deposition, or surface modification using plasma is widely used in various industrial fields such as a semiconductor manufacturing apparatus and a liquid crystal display manufacturing apparatus.
[0003]
As a typical apparatus for performing such plasma processing, there is a “microwave excitation type” plasma processing apparatus that excites plasma by microwaves.
[0004]
FIG. 12 is a schematic diagram showing the structure of a microwave excitation type plasma processing apparatus. This apparatus includes a processing chamber 102, a transmission window 104 made of a flat dielectric plate provided on the upper surface of the processing chamber 102, a slot antenna 106 provided outside the transmission window 104, and a slot antenna 106. A microwave waveguide 108 for introducing a microwave and a stage 112 for mounting and holding an object W such as a semiconductor wafer in a processing space 110 below the transmission window 104 are provided.
[0005]
The processing chamber 102 can maintain a reduced pressure atmosphere formed by an evacuation system (not shown), and a gas introduction pipe 114 for introducing a processing gas into the processing space 110 is connected to a side surface of the chamber 102.
[0006]
For example, when performing an etching process on the surface of the workpiece W using this plasma processing apparatus, first, the workpiece W is placed on the stage 112 with the surface facing upward. . Next, after the processing space 110 is decompressed by a vacuum exhaust system (not shown), an etching gas as a processing gas is introduced into the processing space 110 from the gas introduction pipe 114. Thereafter, a microwave is introduced from the microwave waveguide 108 to the slot antenna 106 in a state where an atmosphere of a processing gas is formed in the processing space 110.
[0007]
The microwave introduced into the radial line slot antenna 106 is radiated from the lower surface of the slot antenna 106 toward the transmission window 104, passes through the transmission window 104, and is radiated to the processing space 110. A plasma of a processing gas is formed in the processing space 110 by the microwave energy radiated to the processing space 110. When the electron density in the plasma generated in this way becomes higher than the density (cutoff density) that can shield the microwaves transmitted through the transmission window 104, the microwaves enter the processing space 110 from the lower surface of the transmission window 104 by a certain distance. (Skin Depth) Reflected until d enters, and a microwave standing wave is formed between the reflection surface of the microwave and the lower surface of the slot antenna 106.
[0008]
Then, the reflection surface of the microwave becomes a plasma excitation surface, and stable plasma is excited on this plasma excitation surface. The active species and decomposed species formed by the stable plasma excited on the plasma excitation surface diffuse and fly to the surface of the workpiece W, so that plasma processing such as etching proceeds.
[0009]
By the way, since the area of semiconductor wafers and glass substrates for liquid crystal displays that are to be processed W is increasing year by year, a plasma generating apparatus having a high density and a uniform density over a large area is required for plasma processing of these. It is said that.
[0010]
In some cases, the surface of the workpiece W having a complicated three-dimensional shape may be uniformly plasma-treated, or conversely, only a part of the workpiece W may be plasma-treated.
[0011]
In response to these requirements, in the case of the conventional plasma processing apparatus as illustrated in FIG. 12, the distribution of the plasma formed in the processing space 110 is reduced by devising the distribution of the microwave introduced from the slot antenna 106. Attempts have been made to optimize.
[0012]
For example, as the slot antenna 106, a “radial line slot antenna” in which a large number of slots are distributed over the entire lower surface thereof may be used. By radiating the microwave introduced from the microwave waveguide 108 through these many slots, the microwave can be radiated almost uniformly into the processing space 110, so that the plasma of the processing gas is made uniform. Therefore, it should be possible to perform a uniform plasma treatment on the surface of the workpiece W.
[0013]
However, even with such a plasma processing apparatus, the surface of the workpiece W may not be uniformly plasma processed. For example, when the pressure in the processing space 110 is set to about 40 Pa (Pascal) or less, electrons in the plasma are lost due to diffusion near the side wall of the processing chamber 102, thereby reducing the electron density and the microwave. Insufficient shielding. For this reason, the standing wave of the microwave is not formed well, and the density of the plasma excited in this portion may be reduced. As a result, as compared with the central portion of the workpiece W, the ion current incident on the peripheral portion of the workpiece W is reduced, and “unevenness” occurs in the plasma processing on the surface of the workpiece W.
[0014]
In order to solve such a problem, Japanese Patent Laid-Open No. 2001-167900 proposes to form a uniform plasma by providing a distribution in the “thickness” and “dielectric constant” of the transmission window 104. ing.
[0015]
[Problems to be solved by the invention]
However, all of these conventional plasma processing apparatuses are based on the idea of using plasma formed in the range of the skin depth d in the vicinity of the transmission window 104 that substantially constitutes a part of the wall surface of the chamber 102. Is.
[0016]
In the case of high-frequency plasma, the skin depth d is only a few millimeters to a few centimeters, and electron acceleration occurs only in the immediate vicinity of the transmission window 104. Therefore, the active species, decomposed species, reactive species, and the like formed by this plasma are recombined with other charged particles and reactive species before they diffuse in the processing space 110 and fly to the surface of the workpiece W. Or inactivation. Further, among these active species and the like, those having a short lifetime may be inactivated before reaching the surface of the workpiece W.
[0017]
Furthermore, in these conventional plasma processing apparatuses, the plasma is generated only in the vicinity of the transmission window, that is, the wall surface of the chamber, and since the distance from the plasma to the workpiece W is large, the distribution is locally strong. It was also difficult to meet the demand for plasma processing.
[0018]
The present invention has been made on the basis of recognition of such a problem, and its purpose is to generate plasma capable of forming plasma having a desired intensity distribution in the immediate vicinity of an object to be processed based on a different idea from the conventional one. An apparatus and a plasma processing apparatus including the same are provided.
[0019]
[Means for Solving the Problems]
  In order to achieve the above object, a first plasma generator of the present invention comprises:
  A vacuum chamber capable of maintaining an atmosphere reduced in pressure than the atmosphere;
  A transmission window for introducing microwaves from outside to inside of the vacuum chamber;
  A waveguide that is provided in the chamber, guides the microwave introduced through the transmission window, and emits the microwave in the chamber;
  With
  The waveguide has a dielectric and a metal coating layer covering a part of the periphery of the dielectric,
Emitting the microwave from a portion not covered by the coating layer;
  The plasma can be generated by the microwave emitted from the waveguide.
[0020]
According to the above configuration, it is possible to generate plasma by guiding and emitting a microwave to an arbitrary location inside the chamber by the waveguide.
[0021]
  The second plasma generator of the present invention is
  A vacuum chamber capable of maintaining an atmosphere reduced in pressure than the atmosphere;
  A waveguide that protrudes toward the inside of the chamber, guides the microwave introduced from the outside of the chamber, and emits the microwave in the chamber;
  With
  The waveguide has a dielectric and a metal coating layer covering a part of the periphery of the dielectric,
Emitting the microwave from a portion not covered by the coating layer;
  The plasma can be generated by the microwave emitted from the waveguide.
[0022]
Even in the above-described configuration, it is possible to generate plasma by guiding a microwave to an arbitrary place inside the chamber by the waveguide projecting toward the inside of the chamber.
[0025]
Further, when the waveguide is made of a dielectric, it is easy to realize microwave guiding and emission.
[0026]
If the waveguide further includes a metal coating layer covering a part of the periphery of the dielectric, and the microwave is emitted from a portion not covered by the coating layer, Microwaves can be guided with low loss and emitted with high intensity at a desired position to generate plasma.
[0027]
On the other hand, the first plasma processing apparatus of the present invention is
One of the above plasma generators is provided, and plasma processing of an object to be processed can be performed by plasma generated by microwaves emitted from the waveguide.
[0028]
  The second plasma processing apparatus of the present invention is
  A vacuum chamber capable of holding an object to be processed and maintaining an atmosphere depressurized from the atmosphere;
  A waveguide that projects from the wall surface of the chamber toward the object to be processed, guides the microwave introduced from the outside of the transmission chamber, and emits it in the vicinity of the object to be processed;
  With
  The waveguide has a dielectric and a metal coating layer covering a part of the periphery of the dielectric,
Emitting the microwave from a portion not covered by the coating layer;
  The plasma can be generated by the microwave emitted from the waveguide.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to specific examples.
[0030]
FIG. 1 is a conceptual diagram for explaining a basic configuration of a main part of a plasma generator according to an embodiment of the present invention.
[0031]
That is, the plasma generator of the present invention includes a chamber 2, a microwave transmission window 4 provided on any wall surface of the chamber 2, and a waveguide provided inside the chamber 2 for guiding the microwave M. 6. As will be described later in detail, the transmission window 4 and the waveguide 6 may be formed as a single unit or separately.
[0032]
The chamber 2 can maintain a reduced pressure atmosphere formed by an evacuation system via an exhaust port 18, and a gas introduction pipe 14 for introducing an atmospheric gas is connected to the inside of the chamber 2. Further, as will be described in detail later, a plasma processing apparatus can be configured by providing a stage (not shown) for placing and holding an object to be processed such as a semiconductor wafer in the chamber 2.
[0033]
As will be described in detail later, the transmission window 4 can be made of a dielectric material such as alumina, for example, and serves to transmit the microwave M supplied from the outside into the chamber while maintaining the hermeticity of the chamber 2. Have.
[0034]
The waveguide 6 has a role of guiding and emitting the microwave M introduced into the chamber through the transmission window 4. That is, the microwave M is supplied from the outside through a microwave waveguide (not shown), and is introduced into the waveguide 6 through the transmission window 4. The microwave excited inside the waveguide 6 through the transmission window 4 leaks from the surface of the waveguide 6, ionizes the gas by electron acceleration in the space near the surface, and generates the plasma P of the atmospheric gas. Generate.
[0035]
That is, according to the present invention, the microwave M introduced into the chamber 2 from the transmission window 4 is guided by the waveguide 6 and emitted from the surface thereof, so that at any place inside the chamber 2, Plasma P can be formed. That is, by devising the shape of the waveguide 6, a desired plasma distribution can be formed inside the chamber 2.
[0036]
For example, if the shape of the waveguide 6 is devised and a microwave is guided from the transmission window 4 to the workpiece W, plasma is generated in the very vicinity of the workpiece W, and extremely high efficiency plasma processing is performed. Can be applied.
[0037]
Further, by devising the shape of the waveguide 6, it becomes possible to generate uniform and powerful plasma over a large area, or only a specific part of the object to be processed is subjected to plasma processing locally. You can also.
[0038]
Here, since the high-density plasma formed around the waveguide 6 reflects the microwave M almost 100%, boundary conditions similar to metal are formed for the microwave. That is, the electromagnetic field inside the waveguide 6 has the same spatial distribution as the electromagnetic field inside the waveguide or resonator made of the same type of metal wall. Therefore, the spatial distribution of the electromagnetic field inside the waveguide 6 can be analyzed by approximating that in such a metal wall waveguide or resonator.
[0039]
The shape of the waveguide 6 shown in FIG. 1 is conceptual only, and as will be described in detail later, the shape can be variously deformed depending on the required distribution of plasma P. it can.
[0040]
The material constituting the waveguide 6 is preferably a material that transmits the microwave M with low loss and has durability against the plasma P of the generated atmospheric gas. Examples of the material include dielectrics such as quartz, alumina, sapphire, and aluminum nitride. These dielectrics have a low power factor with respect to microwaves, good heat resistance, are not easily sputtered or etched by plasma, and have a low possibility of contamination inside the chamber 2 even if etched.
[0041]
According to the present invention, the waveguide 6 is provided in the chamber 2 and does not need to maintain a vacuum tightly. That is, in the case of a conventional plasma processing apparatus as illustrated in FIG. 12, the transmission window 104 that transmits microwaves has a role of ensuring airtightness for maintaining a vacuum at the same time as transmitting microwaves. Accordingly, there are practical limitations on the shape, position, thickness, and the like.
[0042]
On the other hand, according to the present invention, the transmission window 4 and the waveguide 6 can be provided separately. That is, the waveguide 6 does not need the role of a vacuum seal, and its shape, size, position, material, etc. can be freely determined, and a desired plasma distribution can be formed inside the chamber 2. Becomes easy.
[0043]
Here, the material of the transmission window 4 needs to transmit microwaves with low loss and maintain the airtightness of the chamber 2 while partitioning the waveguide space 4 and the vacuum chamber 2. As such a material, a dielectric such as quartz, alumina, or sapphire can be used. These dielectrics have a low power factor for microwaves, have mechanical strength that can withstand the pressure difference between vacuum and atmospheric pressure, have good heat resistance, and even when sputtered or etched by plasma, There is also a low risk of contamination of the workpiece in the chamber.
[0044]
In this way, similar materials can be used for the transmissive window 4 and the waveguide 6, but in the present invention, the transmissive window 4 and the waveguide 6 are formed of the same material. Alternatively, it may be formed of different materials.
[0045]
And in this invention, you may comprise the transmission window 4 and the waveguide 6 as integral. In this case, for example, the transmission window 4 and the waveguide 6 may be integrally formed from the same material from the beginning, or after the transmission window 4 and the waveguide 6 are formed of the same or different materials, Both may be joined together.
[0046]
FIG. 2 is a conceptual diagram showing a first specific example of the plasma generator of the present invention. In this figure, the same elements as those described above with reference to FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0047]
In the case of the plasma generator of this specific example, a ring-shaped waveguide 6A is provided inside the chamber 2. The ring-shaped waveguide 6A can be formed of a dielectric and has a substantially rectangular vertical cross section.
[0048]
A transmission window 4 made of a dielectric is provided on the wall surface of the chamber 2, and the microwave M is introduced into the ring-shaped waveguide 6 </ b> A through the transmission window 4. The introduced microwave M is guided through the ring-shaped waveguide 6A and leaks from the surface thereof, thereby generating plasma in the vicinity of the waveguide 6A.
[0049]
Here, only one transmission window 4 may be provided, or a plurality of transmission windows 4 may be provided. Further, the opening shape is not limited to the circular shape as illustrated, and various shapes can be used.
[0050]
For example, a part of the microwave M introduced through the transmission window 4 propagates through the ring-shaped waveguide 6A to one side (for example, clockwise), and the remaining part of the microwave M is a ring-shaped waveguide. When 6A propagates in the opposite direction (for example, counterclockwise), a standing wave is formed inside the ring-shaped waveguide 6A due to the interference of the microwaves propagating in the opposite directions. Such standing waves leak out around the ring-shaped waveguide 6A, so that plasma can be generated therearound.
[0051]
On the other hand, when an action as a directional coupler is added to the transmission window 4, a traveling wave of microwaves can be excited inside the ring-shaped waveguide 6A. That is, by appropriately adjusting the shape, number, size, arrangement relationship, and the like of the transmission window 4, the microwave is propagated in the ring-shaped waveguide 6A only in one direction (for example, clockwise). Can be introduced. In this way, a wave field of microwave traveling waves can be formed in the ring-shaped waveguide 6A. Furthermore, if the size of the ring-shaped waveguide 6A is set so that the microwave traveling wave formed in this way resonates, the microwave traveling wave is resonated to generate high-strength plasma. can do. Specifically, the pipe length in the circumferential direction of the ring-shaped waveguide 6A may be made substantially equal to an integral multiple of the wavelength of the traveling wave of the microwave propagating through the inside.
[0052]
Thus, when the ring-shaped waveguide 6A satisfies the resonance condition of the microwave traveling wave, the microwave component input from the transmission window 4 to the ring-shaped waveguide 6A is the role of the “spring” of the pendulum type timepiece. Have That is, it has a role of compensating for a loss component that is emitted into the vacuum chamber 2 and contributes to the formation of plasma among the traveling waves propagating through the ring-shaped waveguide 6A that is a resonator. Thus, in the ring-shaped waveguide 6A, a wave field is always formed by a traveling wave of a microwave having a constant intensity, and a uniform and high-intensity plasma can be generated therearound.
[0053]
Therefore, for example, if the workpiece W is arranged under the ring-shaped waveguide 6, a plasma processing apparatus capable of high-efficiency and uniform plasma processing can be configured.
[0054]
In the present invention, the vertical cross-sectional shape of the ring-shaped waveguide is not limited to a substantially rectangular shape. For example, as illustrated in FIG. 3, a substantially semicircular vertical cross-sectional shape may be provided, and various other shapes may be provided.
[0055]
FIG. 4 is a conceptual diagram showing a third specific example of the plasma generator of the present invention. With respect to this figure, elements similar to those described above with reference to FIGS. 1 to 3 are marked with the same reference numerals and not described in detail.
[0056]
In this specific example, a ring-shaped waveguide body 6 </ b> C is provided along the cylindrical wall surface of the substantially cylindrical chamber 2. This ring-shaped waveguide 6C can also be formed of a dielectric and has a substantially rectangular vertical cross section.
[0057]
Then, the microwave M is introduced into the ring-shaped waveguide 6C from the outside through the transmission window 4 provided on the cylindrical wall surface of the chamber 2, and a wave field such as a standing wave, a traveling wave, and a resonant traveling wave is formed. The Also in this specific example, only one transmission window 4 may be provided, or a plurality of transmission windows 4 may be provided.
[0058]
As described above, by providing the ring-shaped waveguide 6 </ b> C along the side wall surface of the chamber 2, uniform and strong plasma can be generated near the outer periphery of the chamber 2. Therefore, for example, uniform and rapid plasma processing can be performed on the side surface of the substantially cylindrical workpiece W.
[0059]
In this specific example, the vertical cross-sectional shape of the ring-shaped waveguide 6 is not limited to a substantially rectangular shape. For example, a substantially semicircular vertical cross-sectional shape may be given as illustrated in FIG. Various shapes can be given.
[0060]
FIG. 6 is a conceptual diagram showing a fifth specific example of the plasma generator of the present invention. Also in this figure, the same elements as those described above with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0061]
In the case of this specific example, a rod-shaped waveguide 6E is provided along the upper wall surface of the substantially cylindrical chamber 2. This rod-shaped waveguide 6E can also be formed of a dielectric.
[0062]
Then, the microwave M is guided from the outside to the rod-shaped waveguide 6E through the transmission window 4 provided on the cylindrical wall surface of the chamber 2, and plasma is formed around the microwave by the leaked microwave. Is done. At this time, for example, the introduced microwave can be resonated by appropriately setting the shape and size of the rod-shaped waveguide 6E, the attachment position of the transmission window 4, the opening shape, and the size.
[0063]
Such a rod-shaped waveguide is relatively easy to analyze the wave field of the microwaves excited inside, and it is easy to design a plasma with a predetermined distribution in the chamber. There are also advantages.
[0064]
For example, FIG. 7 is a schematic diagram showing an example of a plasma generator in which a plurality of such rod-shaped waveguides are arranged. In this way, a plurality of rod-shaped waveguides 6E are arranged in a direction perpendicular to the circumferential wall surface, and microwaves are introduced into each of them from the transmission window 4, thereby generating uniform and high-intensity plasma in the chamber 2. It is easy to form.
[0065]
Still further, such a rod-shaped waveguide need not be linear.
[0066]
For example, FIG. 8 is a schematic diagram showing an example of a plasma generating apparatus provided with a bent rod-shaped waveguide. That is, in the case of this example, a plurality of rod-shaped waveguides 6F bent substantially at right angles are arranged from the upper surface of the chamber 2 to the side wall surface. Then, a microwave is introduced into each waveguide 6 </ b> F through the transmission window 4 provided on the upper surface of the chamber, and plasma with a predetermined distribution is formed in the chamber 2.
[0067]
FIG. 9 is a schematic diagram showing a plasma generator according to a further modification of the present invention. Also in this figure, the same elements as those described above with reference to FIGS. 1 to 8 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0068]
In the case of this specific example, the waveguide 6G includes a dielectric 65 that opens in a horn shape, and a metal coating layer 66 that covers the side surface thereof. The microwave M introduced from the transmission window 4 is guided through the dielectric 65, but does not leak out around the dielectric 65 by the metal coating layer 66 therearound. That is, the microwave is guided in a state of being confined inside the metal coating layer 66, and is emitted at the open end on the lower surface of the waveguide 6G where the metal coating layer 66 is not provided. Therefore, strong intensity plasma can be generated in the vicinity of the open end.
[0069]
Thus, by providing a metal coating layer on a part of the waveguide, it is possible to guide the microwave in a confined state without leaking, and to emit the microwave at a desired position in the chamber. As a result, strong plasma can be generated.
[0070]
The horn shape as illustrated in FIG. 9 is preferable in that uniform plasma can be formed on the substantially circular workpiece W.
[0071]
However, such a metal coating layer can be similarly applied to waveguides of all shapes, and by appropriately covering the periphery of the waveguide with a metal coating layer, the loss of microwaves can be prevented and the chamber can be prevented. It is possible to guide efficiently to a predetermined position in the inside.
[0072]
FIG. 10 is a schematic diagram showing a plasma generator according to a further modification of the present invention. Also in this figure, the same elements as those described above with reference to FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0073]
In the case of this specific example, the waveguide 6H also has a metal coating layer 66 that covers its side surface, and a dielectric that guides microwaves is provided therein. The microwave M introduced from the transmission window 4 is guided in a state of being confined in the waveguide 6H, and is emitted from the open end below the microwave M to generate strong plasma in the vicinity thereof.
[0074]
Therefore, extremely strong plasma can be locally formed in the chamber 2 using such a waveguide 6H, and spot plasma processing can be performed. Furthermore, by providing a mechanism for relatively moving the waveguide 6H and the workpiece W, it is possible to scan the workpiece W by plasma processing.
[0075]
Furthermore, as illustrated in FIG. 11, an emission portion 68 made of a dielectric or the like may be provided at the tip of such a waveguide 6H. In this way, the microwave introduced from the transmission window 4 can be guided with high efficiency while preventing loss in the waveguide 6H, and can be emitted to the surroundings with a predetermined distribution in the emission portion 68. . Therefore, a desired distribution of plasma can be formed at a desired location in the chamber 2 in accordance with the shape and size of the emission portion 68.
[0076]
The embodiments of the present invention have been described with reference to specific examples. However, the present invention is not limited to these specific examples.
[0077]
For example, elements such as a waveguide, a transmission window, or a microwave power source and a waveguide mechanism provided outside the chamber used in the present invention are appropriately modified by those skilled in the art based on the spirit of the present invention. It is included in the range.
[0078]
Further, the shape and size of the chamber, or the positional relationship with the waveguide and the transmission window are not limited to those shown in the drawings, and can be appropriately determined in consideration of the contents and conditions of the plasma treatment.
[0079]
Furthermore, in the above-described specific examples, only the main configuration of the plasma generation unit has been described. However, the present invention includes all plasma processing apparatuses having such a plasma generation unit, for example, an etching apparatus and an ashing apparatus. Any plasma processing apparatus realized as a thin film deposition apparatus, a surface treatment apparatus, a plasma doping apparatus, and the like is included in the scope of the present invention.
[0080]
【The invention's effect】
As described above in detail, according to the present invention, the microwave introduced through the transmission window can be guided by the waveguide and emitted to an arbitrary location in the chamber to generate plasma.
[0081]
Therefore, for example, it is possible to easily form a uniform plasma with a large area, or conversely form a strong plasma locally.
[0082]
As a result, plasma processing such as etching, ashing, thin film deposition, surface modification or plasma doping can be carried out uniformly and quickly on large-area semiconductor wafers, liquid crystal display substrates, etc. It is also possible to perform local plasma processing on the object to be processed, which has a great industrial advantage.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram for explaining a basic configuration of a main part of a plasma generating apparatus according to an embodiment of the invention.
FIG. 2 is a conceptual diagram showing a first specific example of the plasma generator of the present invention.
FIG. 3 is a conceptual diagram showing a second specific example of the plasma generator of the present invention.
FIG. 4 is a conceptual diagram showing a third specific example of the plasma generator of the present invention.
FIG. 5 is a conceptual diagram showing a fourth specific example of the plasma generator of the present invention.
FIG. 6 is a conceptual diagram showing a fifth specific example of the plasma generator of the present invention.
FIG. 7 is a schematic diagram showing an example of a plasma generator in which a plurality of rod-shaped waveguides are arranged.
FIG. 8 is a schematic diagram showing an example of a plasma generator provided with a bent rod-shaped waveguide.
FIG. 9 is a schematic diagram showing a plasma generator according to a further modification of the present invention.
FIG. 10 is a schematic diagram showing a plasma generator according to a further modification of the present invention.
FIG. 11 is a schematic diagram showing a specific example in which an emission portion 68 made of a dielectric or the like is provided at the tip of a waveguide 6H.
FIG. 12 is a schematic diagram showing the structure of a microwave excitation type plasma processing apparatus.
[Explanation of symbols]
2 chambers
4 Transmission windows
6 Waveguide
6A-6D Ring-shaped waveguide
6E, 6F Rod-shaped waveguide
14 Gas introduction pipe
18 Exhaust vent
61 Antenna
62 Dielectric
63 Metal coating layer
65 Dielectric
66 Metal coating layer
68 Release part
96 stages
102 chambers
102 processing chamber
104 Transmission window
106 slot antenna
108 Microwave waveguide
110 processing space
112 stages
M microwave
P Plasma
W Workpiece
d Skin depth

Claims (8)

A vacuum chamber capable of maintaining an atmosphere reduced in pressure than the atmosphere;
A transmission window for introducing microwaves from outside to inside of the vacuum chamber;
A waveguide that is provided in the chamber, guides the microwave introduced through the transmission window, and emits the microwave in the chamber;
With
The waveguide has a dielectric and a metal coating layer covering a part of the periphery of the dielectric,
Emitting the microwave from a portion not covered by the coating layer;
A plasma generator capable of generating plasma by microwaves emitted from the waveguide. A vacuum chamber capable of maintaining an atmosphere reduced in pressure than the atmosphere;
A waveguide that protrudes toward the inside of the chamber, guides a microwave introduced from the outside of the chamber, and emits the microwave in the chamber;
With
The waveguide has a dielectric and a metal coating layer covering a part of the periphery of the dielectric,
Emitting the microwave from a portion not covered by the coating layer;
A plasma generator capable of generating plasma by microwaves emitted from the waveguide. The dielectric is formed to open in a horn shape,
  3. The plasma generating apparatus according to claim 1, wherein the metal coating layer covers an outer side surface and an inner side surface of the horn, and does not cover a tip of the horn. The dielectric is provided extending into the chamber;
  3. The plasma generating apparatus according to claim 1, wherein the metal coating layer covers a side surface of the dielectric and does not cover a front end thereof. 4. 2. The dielectric according to claim 1, further comprising: a waveguide part whose side surface is covered with the metal coating layer; and an emission part which is provided at a tip of the dielectric part and whose side surface is not covered with the metal coating layer. Or the plasma generator of 2. The plasma generator according to claim 1, wherein the dielectric is one selected from the group consisting of quartz, alumina, sapphire, and aluminum nitride. The plasma generator according to any one of claims 1 to 6, comprising:
A plasma processing apparatus characterized in that plasma processing of an object to be processed can be performed by plasma generated by microwaves emitted from the waveguide. A vacuum chamber capable of holding an object to be processed and maintaining an atmosphere depressurized from the atmosphere;
A waveguide that projects from the wall surface of the chamber toward the object to be processed, guides the microwave introduced from the outside of the transmission chamber, and emits it in the vicinity of the object to be processed;
With
The waveguide has a dielectric and a metal coating layer covering a part of the periphery of the dielectric,
Emitting the microwave from a portion not covered by the coating layer;
A plasma processing apparatus characterized in that plasma can be generated by microwaves emitted from the waveguide.

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