JP5703688B2 - Microwave plasma processing apparatus and microwave plasma processing method - Google Patents

Description

  The present invention relates to a microwave plasma processing apparatus including a chamber that performs processing in an internal space, and a microwave plasma processing method that generates a plasma by introducing a microwave into the chamber and executes a predetermined process. In particular, the present invention relates to a microwave plasma processing apparatus and a microwave plasma processing method for introducing a microwave through a coaxial waveguide.

Chemical vapor deposition (CVD) is a technology for depositing reaction products in the form of a film on the surface of an object to be processed by vapor phase growth in a high-temperature atmosphere using a processing gas that does not react at room temperature. It is widely used for manufacturing, surface modification and coating of metals and ceramics.
Recently, as a surface coating of plastic containers in low-pressure plasma CVD, it is also applied to improve gas barrier properties.

Plasma CVD is a method for growing thin films using plasma. Basically, it is generated by dissociating and combining gases containing a processing gas under a reduced pressure with electric energy of a high electric field. This is a method of depositing the processed material on the processing object by chemical reaction in the gas phase or on the processing object.
The plasma state is realized by glow discharge, corona discharge, arc discharge, etc. For example, as a method of glow discharge, a method using direct current glow discharge, a method using high frequency glow discharge (high frequency plasma CVD). Further, a method using microwave discharge (microwave plasma CVD) is known.

  Among these, the microwave plasma CVD can greatly simplify the configuration of the apparatus, and the degree of decompression in the apparatus is such that when the inner surface of the plastic container is processed, the microwave discharge is only in the plastic container. Therefore, it is not necessary to maintain the entire apparatus in a high vacuum, which is excellent in terms of ease of operation and productivity.

By the way, in microwave plasma CVD, a microwave generated by a microwave oscillator or the like is sent to a chamber in which an object to be processed is stored via a hollow waveguide or a coaxial waveguide.
Here, the hollow waveguide is a metal tube having a rectangular or circular cross section. Since the inside of the tube is hollow, the microwave propagates in a TE mode (Transverse Electric mode) or a TM mode (Transverse Magnetic mode).
On the other hand, the coaxial waveguide has a tubular outer conductor and a rod-like or tubular inner conductor arranged coaxially. With this configuration, the microwave propagates in a TEM mode (Transverse Electromagnetic mode).

Further, when the hollow waveguide and the coaxial waveguide are connected, a coaxial waveguide converter is used.
The coaxial waveguide converter switches, for example, a TE mode microwave propagated by a hollow rectangular waveguide to a TEM mode microwave and sends the microwave to the coaxial waveguide.

A technique for propagating microwaves to the chamber using these hollow waveguide, coaxial waveguide converter, and coaxial waveguide has been proposed.
For example, a cylindrical container with the top and bottom surfaces sealed, an inner conductor of a coaxial waveguide inserted from the center of the top surface into the cylindrical container, and the center of the bottom surface of the cylindrical container And a gas supply pipe inserted into the cylindrical container from the portion, and the internal conductor and the gas supply pipe are arranged on the same axis (for example, Patent Document 1, 2).

  According to this technique, since the coaxial resonator is constituted by the inner conductor, the gas supply pipe, and the cylindrical container, it is possible to reduce the loss of the coupling of the microwave energy to the coaxial resonator. Moreover, the distribution of the electromagnetic field in the cylindrical container by the microwave energy can be made uniform in a stable state at all times. Thereby, the plasma intensity of the source gas in the cylindrical container can be made uniform, and a thin film having a uniform thickness can be formed on the inner surface of the plastic container.

JP 2006-152418 A JP 2007-217717 A

However, the techniques described in Patent Documents 1 and 2 described above have the following problems.
For example, when the object to be processed is a bottle, a gas nozzle for supplying a reaction gas to the inside of the bottle is installed inside the chamber. This gas nozzle is connected to the central axis of the inner conductor of the coaxial waveguide. When extended, only one was installed on this extension shaft.
For this reason, only one bottle can be placed in the chamber, and a plurality of bottles cannot be processed simultaneously.

  In addition, when only one gas nozzle is installed on the extended axis when the central axis of the inner conductor of the coaxial waveguide is extended, between the inner conductor and the gas supply pipe (the bottle is placed upside down). When it was, plasma was generated only at the bottom of the bottle). Thereby, a thin film was formed only on the bottom surface of the bottle, which was a problem.

  The present invention has been considered in view of the above circumstances, and it is an object of the present invention to provide a microwave plasma processing apparatus capable of processing a plurality of bottles and capable of forming a high-quality thin film on the entire inner surface of the bottle. To do.

In order to achieve this object, a microwave plasma processing apparatus of the present invention includes a coaxial waveguide that supplies a microwave to a chamber, a gas nozzle that supplies a source gas into the chamber, and a base on which the chamber is mounted. The coaxial waveguide has an inner conductor , the inner conductor is inserted into the chamber through the through hole in the top plate portion of the chamber, and the gas nozzle is inserted into the chamber through the through hole in the base. to be erected, is disposed at a position deviated from the central axis of the inner conductor, the distal end of the inner conductor, is a configuration in which from the front end of the gas nozzle was positioned below.
The microwave plasma processing apparatus of the present invention includes a coaxial waveguide that supplies a microwave to the chamber, a gas nozzle that supplies a source gas to the inside of the chamber, and a base on which the chamber is mounted, and is coaxial. The waveguide has an inner conductor, the inner conductor is inserted from the through hole of the base toward the inside of the chamber, and the gas nozzle is inserted through the through hole of the base and deviated from the central axis of the inner conductor. The tip of the inner conductor is positioned at a position close to the height of the tip of the gas nozzle or above the tip of the gas nozzle.

The microwave plasma processing method of the present invention is a microwave plasma processing method for performing a predetermined process on an object placed in a chamber, and the chamber is passed through a through hole of a base on which the chamber is placed. A process of supplying a source gas into the chamber from a gas nozzle that is erected inside and disposed at a position shifted from the central axis of the chamber, and is inserted into the chamber through a through hole in the top plate portion of the chamber, Plasma is generated by supplying microwaves into the chamber through a coaxial waveguide having an inner conductor located on the central axis of the chamber, the tip of which is located below the tip of the gas nozzle. And a step of causing the
The microwave plasma processing method of the present invention is a microwave plasma processing method for performing a predetermined process on an object placed in a chamber, and is inserted through a through hole of a base on which the chamber is placed. The step of supplying the raw material gas into the chamber from the gas nozzle arranged at a position shifted from the central axis of the chamber, and the insertion from the through hole of the base toward the inside of the chamber, and the central nozzle of the chamber Microwave is supplied into the chamber through a coaxial waveguide having an inner conductor, the tip of which is close to the height of the tip of the gas nozzle, or above the tip of the gas nozzle. And a step of generating plasma.

According to the microwave plasma processing apparatus and the microwave plasma processing method of the present invention, since the gas nozzle is disposed at a position displaced from the central axis of the internal conductor, a plurality of the gas nozzles can be disposed. Thereby, a plurality of film forming processes on the bottle can be performed simultaneously.
Moreover, since the gas nozzle is disposed at a position shifted from the central axis of the inner conductor, the length of the inner conductor can be freely selected. And by increasing the length of the inner conductor, a good quality thin film can be formed on the entire inner surface of the bottle.

It is front sectional drawing which shows the structure of the microwave plasma processing apparatus in 1st embodiment of this invention. In 1st embodiment, it is an upper surface sectional view showing composition of a chamber part, (i) is a figure showing composition of a chamber which can store two bottles, (ii) stores three bottles The figure which shows the structure of a possible chamber, (iii) is a figure which shows the structure of the chamber which can accommodate four bottles. In 1st embodiment, it is a top surface sectional view showing composition of a chamber in which fewer bottles were stored to a chamber which can process a plurality of bottles. In 1st embodiment, it is upper surface sectional drawing which shows the structure of the chamber which can accommodate the bottle whose cross-sectional shape of a trunk | drum is a square. In 1st embodiment, it is top surface sectional drawing which shows the structure of the chamber which can accommodate two bottles with the cross-sectional shape of a trunk | drum, Comprising: (i) is on the extension line | wire of the longitudinal direction of the trunk | drum cross section of a bottle. The configuration in which the bottle is arranged so that the central axis of the chamber is located, and (ii) shows the configuration in which the bottle is arranged so that the central axis of the chamber is located on the extension line in the short direction of the body section of the bottle. In 1st embodiment, it is upper surface sectional drawing which shows the structure of the chamber which can accommodate four bottles where the cross-sectional shape of a trunk | drum is a rectangle, (i) is on the extension line | wire of the longitudinal direction of the trunk | drum cross section of a bottle. The configuration in which the bottle is arranged so that the central axis of the chamber is located, and (ii) shows the configuration in which the bottle is arranged so that the central axis of the chamber is located on the extension line in the short direction of the body section of the bottle. In 1st embodiment, it is a flowchart which shows operation | movement of the microwave plasma processing apparatus of this invention. In 1st embodiment, it is a graph which shows the film thickness distribution of the bottle inner surface when the length of an internal conductor is changed. In 1st embodiment, it is an analysis figure which shows the electric field distribution in a chamber when the length of an internal conductor is changed. In 1st embodiment, it is an analysis figure which shows the electric field distribution in a chamber when changing the internal diameter of a high chamber. It is front sectional drawing which shows the structure of the microwave plasma processing apparatus in 2nd embodiment of this invention. In 2nd embodiment, it is an analysis figure which shows the electric field distribution in a chamber when the length of an internal conductor is changed. It is front sectional drawing which shows the structure of the microwave plasma processing apparatus in 3rd embodiment of this invention. It is an analysis figure which shows the electric field distribution in the chamber in the microwave plasma processing apparatus shown in FIG.

  Hereinafter, preferred embodiments of a microwave plasma processing apparatus and a microwave plasma processing method according to the present invention will be described with reference to the drawings.

[First embodiment]
First, a first embodiment of a microwave plasma processing apparatus and a microwave plasma processing method of the present invention will be described with reference to FIG.
This figure is a front sectional view showing the configuration of the microwave plasma processing apparatus of the present embodiment.

(1) Overall Configuration As shown in the figure, the microwave plasma processing apparatus 1a includes a processing chamber 10a and a waveguide 20a.
The processing chamber 10a includes a chamber 11a, a gas nozzle 12, and a base 13a.
The chamber 11a is formed in a substantially cylindrical shape, and is placed on the upper surface 13-1 of the base 13a so that the two circular surfaces of the cylindrical shape become the upper surface and the lower surface, respectively.
The shape of the chamber 11a is not particularly required to be a cylinder, and may be a rectangle or the like according to equipment specifications.

The gas nozzle 12 is a pipe-shaped member for sending processing gas into the bottle. The gas nozzle 12 is erected through a through hole 13-2 formed in the base 13a in the vertical direction.
The bottle is placed in an inverted state on the upper surface 13-1 of the base 13a. Further, the bottle is placed such that the gas nozzle 12 is positioned on the central axis thereof. For this reason, the same number of bottles as the gas nozzles 12 can be placed at the maximum.

The arrangement of these gas nozzles 12 and bottles is shown in FIGS.
(I)-(iii) is sectional drawing when the microwave plasma processing apparatus 1a is seen from upper direction (about (iii), it is II sectional drawing of FIG. 1).
As shown in (i) to (iii) of the figure, a plurality of gas nozzles 12 are provided. For example, two lines are provided in the same figure (i), three lines are provided in the same figure (ii), and four lines are provided in the same figure (iii).
The plurality of gas nozzles 12 are arranged at positions shifted from the central axis 11-1 of the chamber 11a. Further, the plurality of gas nozzles 12 are arranged in rotational symmetry with the central axis 11-1 of the chamber 11a as an axis of symmetry.

The bottle is placed in an inverted state at a position where the gas nozzle 12 is provided. For this reason, a plurality of bottles can be placed inside the chamber 11a. And the several bottle is arrange | positioned by the rotational symmetry which makes the central axis 11-1 of the chamber 11a a symmetry axis similarly to the gas nozzle 12. FIG.
By arranging in this way, the gas nozzle 12 and the bottle have the same distance from the inner conductor 23a-2 (described later) of the coaxial waveguide 23a. Thereby, the electric field distribution around the bottle becomes equal, and the film thickness of the thin film formed on the bottle can be made uniform.

The base 13a is a basic part of the microwave plasma processing apparatus 1a.
The base 13a is provided with an exhaust part 13-3 which is a through hole drilled in the vertical direction. Further, a vacuum pump (not shown) is connected to the exhaust part 13-3. By operating this vacuum pump, the air inside the chamber 11a can be exhausted through the exhaust unit 13-3, and the inside of the chamber 11a can be lowered to a predetermined degree of vacuum. Note that the predetermined degree of vacuum is a degree of vacuum at which the raw material gas is turned into plasma by the supplied microwave energy.

The waveguide unit 20a includes a hollow waveguide 21, a coaxial waveguide converter 22, and a coaxial waveguide 23a.
The hollow waveguide 21 is a cylindrical waveguide having a rectangular or circular cross section. One end of the hollow waveguide 21 is connected to a microwave oscillator, an impedance matching unit, an isolator (none of which is shown), and the other end is connected to a coaxial waveguide converter 22. Yes.

The microwave oscillator generates and outputs a microwave at a predetermined oscillation frequency (for example, 2.45 GHz) using, for example, a magnetron.
The impedance matching unit adjusts the impedance with the load. As this impedance matching device, for example, there are a sleeving tuner and an E-H tuner.

The coaxial waveguide converter 22 has a hollow waveguide side connection portion 22-1 and a coaxial waveguide side connection portion 22-2.
The hollow waveguide side connection portion 22-1 is connected to the hollow waveguide 21 and receives microwaves from the hollow waveguide 21.
The coaxial waveguide side connection portion 22-2 is connected to the coaxial waveguide 23a, and sends a microwave to the coaxial waveguide 23a.
In this coaxial waveguide converter 22, the microwave transmission mode sent from the hollow waveguide 21 is converted from the TE mode or TM mode to the TEM mode and sent to the coaxial waveguide 23a.

The coaxial waveguide 23a connects the coaxial waveguide converter 22 and the top plate portion 11a-2 of the chamber 11a, and the microwave transmitted from the coaxial waveguide converter 22 is supplied to the chamber 11a. Supply to the inside of.
The coaxial waveguide 23a has an outer conductor 23a-1 and an inner conductor 23a-2.
The outer conductor 23a-1 is formed in a cylindrical shape, and connects between the coaxial waveguide side connection portion 22-2 of the coaxial waveguide converter 22 and the top plate portion 11a-2 of the chamber 11a. As a result, the inner hollow portion of the coaxial waveguide converter 22 and the inner hollow portion of the chamber 11a communicate with each other via the inner hollow portion of the outer conductor 23a-1 and the through hole 11a-3 of the top plate portion 11a-2. .

A vacuum partition wall 23-3 is provided inside the outer conductor 23a-1.
The vacuum partition wall 23-3 is a partition wall that protects the vacuum state from reaching the microwave oscillator (not shown) when the chamber 11a is in a vacuum state (depressurized state). Further, the vacuum partition wall 23-3 sends the microwave propagated through the hollow waveguide 21 and the coaxial waveguide converter 22 to the chamber 11a while maintaining the vacuum state of the chamber 11a.

The inner conductor 23a-2 is formed in a rod shape or a cylindrical shape, and is disposed coaxially with the outer conductor 23a-1 inside the outer conductor 23a-1.
In addition, one end of the inner conductor 23a-2 is connected to the inner wall surface of the coaxial waveguide converter 22, and the other end is a through hole formed in the center of the top plate portion 11a-2 of the chamber 11a. It passes through 11a-3 and reaches the inside of the chamber 11a.

Thus, only one inner conductor 23a-2 is provided for one chamber 11a.
The length of the internal conductor 23a-2 will be described later in "(2-1) The length of the internal conductor and the relationship between the internal conductor and the gas nozzle".
Further, as shown in FIGS. 2 (i) to (iii), the inner conductor 23a-2 is desirably arranged coaxially with the central axis 11-1 of the chamber 11a.

(2) Detailed Configuration Next, a detailed configuration of the microwave plasma processing apparatus will be described.
(2-1) The length of the inner conductor and the relationship between the inner conductor and the gas nozzle As shown in FIGS. 1 and 2, the central axes of the inner conductor 23 a-2 and the gas nozzle 12 are not located on a straight line. As shown in FIG. Here, since the internal conductor 23a-2 is disposed on the central axis 11-1 of the chamber 11a, the gas nozzle 12 is disposed at a position shifted from the central axis 11-1. Thereby, since the gas nozzle 12 and the bottle do not exist in the center of the base 13a, the internal conductor 23a-2 can be made longer than before.

The length L (see FIG. 1) of the inner conductor 23a-2 in the chamber is preferably a length determined by the following equation.
L = (λ / 2) × n + α (Formula 1)
Note that λ is a microwave wavelength in vacuum, n is an integer of 1 or more, and α is a length to be added in design.
As will be described later in Example 1, a strong electric field portion is generated around λ / 2 (≈60 mm) around the inner conductor 23a-2.
Furthermore, the positional relationship between the tip of the inner conductor 23a-2 and the tip of the gas nozzle 12 is important, and it is desirable that the tip of the inner conductor 23a-2 has a length that is positioned at least below the tip of the gas nozzle 12. In particular, when the inner conductor 23a-2 is lengthened until the tip of the inner conductor 23a-2 contacts the upper surface 13-1 of the base 13a, the electric field around the gas nozzle 12 becomes stronger. In addition, since the concentration of the electric field near the base of the gas nozzle 12 becomes strong, plasma is emitted from the entire bottle, and the film thickness particularly at the top of the bottle increases.

On the other hand, when the tip of the inner conductor 23a-2 is located above the tip of the gas nozzle 12, the electric field around the gas nozzle 12 and the electric field concentration near the root are weakened, and plasma does not emit light around the bottle. For this reason, no film is formed on the upper part of the bottle (closer to the mouth).
The gas nozzle 12 after being displaced from the central axis of the internal conductor 23a-2 is arranged so that the central axis of the gas nozzle 12 is parallel to the central axis of the internal conductor 23a-2. That is, the direction in which the gas nozzle 12 is displaced is a direction orthogonal to the central axis of the inner conductor 23a-2, and the gas nozzle 12 is not rotated or rotated in any direction.
Further, the inventor conducted an experiment on the relationship between the length of the inner conductor 23a-2 and the film thickness. The contents of this experiment will be described later as (Example 1).

(2-2) Number of Gas Nozzles and Bottles As shown in FIGS. 1 and 2 (i) to (iii), the inner conductor 23a-2 and the gas nozzle 12 are arranged so as not to overlap with each other. It is. Thereby, the number of gas nozzles 12 can be increased and the number of bottles can be increased.
For example, when the gas nozzle 12 and the internal conductor 23a-2 are on the same axis, since only one gas nozzle 12 can be arranged, only one bottle can be arranged. That is, the number of bottles that can be formed in one film formation process is one.
On the other hand, as described above, the gas nozzle 12 of the present embodiment is arranged so as to be shifted from the central axis of the internal conductor 23a-2. Therefore, a plurality of gas nozzles 12 can be arranged, and accordingly, a plurality of bottles can be arranged. Thereby, a thin film can be formed simultaneously on a plurality of bottles by a single film forming process.

As shown in FIG. 2 (i), in the microwave plasma processing apparatus 1a in which two gas nozzles 12 are arranged, only one bottle is placed as shown in FIG. It is also possible to perform a film treatment. Even in this case, stable plasma emission occurs.
Further, as shown in FIG. 2 (ii), in the microwave plasma processing apparatus 1a in which three gas nozzles 12 are arranged, as shown in FIG. 3 (ii), two (or only one) bottles are mounted. It is also possible to perform film formation processing.

  Furthermore, as shown in FIG. 2 (iii), in the microwave plasma processing apparatus 1a in which four gas nozzles 12 are arranged, as shown in FIG. 3 (iii), two bottles (or one or three) are used. It is also possible to perform a film formation process by mounting.

(2-3) Bottle shape and core In FIGS. 1 and 2 (i) to (iii), a bottle having a circular cross-sectional shape of the body is placed inside the chamber 11a. .
However, the cross-sectional shape of the body of the bottle that is the object of film formation by the microwave plasma processing apparatus 1a of the present embodiment is not limited to a circle, and may be, for example, a square or a flat shape.

Here, when the cross-sectional shape of the bottle body is circular or square, the distance between the side surface of the bottle and the inner wall 11-5 of the chamber 11a should be substantially the same as shown in FIGS. Is desirable. That is, a better and more uniform thin film can be formed when the inner wall 11-5 of the chamber 11a has a shape similar to the shape of the bottle.
On the other hand, when a bottle having a flat cross-sectional shape of the body portion is placed, as shown in FIGS. 5 and 6, the inner wall 11-5 of the chamber 11a and the bottle cross-sectional longitudinal side surface are separated from each other. .
Therefore, the core 11-6 is attached to a portion of the inner wall 11-5 facing the bottle cross-section longitudinal side surface. As a result, the distance between the bottle cross-section long side surface and the core 11-6 is substantially the same as the distance between the bottle cross-section short side surface and the inner wall 11-5 of the chamber 11a, and a strong electric field portion is generated around the gas nozzle 12. It is possible to form a high-quality and uniform thin film with a uniform film thickness on the entire bottle.
The core 11-6 is disclosed in "Plasma deposition apparatus and plasma deposition method" described in JP-A-2005-290507.

The core 11-6, as shown in FIGS. 5 (i), (ii), FIGS. 6 (i), (ii), is the most spaced part between the side surface of the bottle and the inner wall 11-5 of the chamber 11a. It is preferable to provide in.
5 (i) and (ii) show the configuration of the microwave plasma processing apparatus 1a provided with two gas nozzles 12, and FIGS. 6 (i) and (ii) show the microwave plasma provided with four gas nozzles 12. FIG. It is the structure of the processing apparatus 1a.

(2-4) Inner Diameter of Chamber The inner diameter of the chamber 11a refers to the diameter of the internal space of the chamber 11a. When processing a plurality of bottles, the diameter of the internal space corresponding to each one bottle is used. Specifically, the length D shown in FIG.
The electric field distribution varies depending on the inner diameter of the chamber 11a.
For example, when the inner diameter is small, the electric field concentrates on the inner conductor 23 a-2, and no strong electric field portion is generated around the gas nozzle 12. On the other hand, when the inner diameter is large, the electric field concentrates around the gas nozzle 12.
For this reason, the inner diameter of the chamber 11a is preferably large, but if it becomes larger than necessary, the distance between the bottle and the chamber wall becomes wide, leading to deterioration of the film quality. Preferably, the bottle and the chamber wall are about 5 to 50 mm.

(2-5) Length of Gas Nozzle The length of the gas nozzle 12 is as described in “A plasma supply gas supply member used for forming a deposited film by the plasma CVD method and the gas supply member described in JP-A-2005-68471”. It is disclosed in “Method for Forming Deposition Film”.

That is, it is desirable that the length N of the gas nozzle 12 is a length determined by the following equation.
N = (λ / 2) × n + α (Formula 2)
Note that λ is a microwave wavelength in vacuum, n is an integer of 1 or more, and α is a length to be added in design.
From Equation 2, it can be seen that, for example, when the microwave frequency is 2.45 GHz, a strong electric field portion is generated around the gas nozzle 12 every λ / 2 (≈60 mm).

(2-6) Length of Hollow Waveguide The hollow waveguide 21 has a length corresponding to the wavelength of the microwave because it propagates the microwave inside.
Thereby, a strong electric field portion can be generated around the gas nozzle 12 for each λg / 2 of the in-tube wavelength of the hollow waveguide 21. For example, when a rectangular waveguide having a hollow cross section of 96 mm × 27 mm is used, λg / 2≈79 mm.

(2-7) Length of coaxial waveguide Since the coaxial waveguide 23a propagates the microwave inside, the length is set according to the wavelength of the microwave.
Thereby, a strong electric field portion can be generated around the gas nozzle 12 for every λg / 2 (≈60 mm) of the in-tube wavelength of the coaxial waveguide 23a.

(3) Microwave Plasma Processing Method Next, an operation procedure (microwave plasma processing method) of the microwave plasma processing apparatus will be described with reference to FIG.

As a preparatory stage, a plurality of gas nozzles 12 are erected on the upper surface 13-1 of the base 13a at positions shifted from the central axis of the inner conductor 23a-2 of the coaxial waveguide 23a. In each of the positions where the gas nozzles 12 are erected, the bottles are placed upside down with their mouths down (bottle placing step, step 10).
Next, the top plate 11a-2 is placed so as to close the upper opening of the chamber 11a, and the chamber 11a is sealed.
Subsequently, a vacuum pump (not shown) is operated to reduce the pressure inside the chamber 11a (in-chamber vacuum processing step, step 11).
Further, the inside of the bottle is decompressed (in-bottle vacuum processing step, step 12).
When the pressure is reduced, the processing gas is introduced into the bottle through the gas nozzle 12 (processing gas introduction step, step 13).

When a predetermined amount of processing gas is supplied, the microwave output from a microwave oscillator (not shown) is then converted into a hollow waveguide 21, a coaxial waveguide converter 22, It propagates through the coaxial waveguide 23a and is introduced into the chamber 11a (microwave introduction process, step 14).
The microwave introduced into the chamber 11a brings the processing gas into a high energy state and a plasma state. The plasma processing gas acts on the inner surface of the bottle and deposits to form a coating film (deposition process, step 15).

(4) Examples Next, examples of the microwave plasma processing apparatus will be described.
(Example 1)
The inventor conducted an experiment on the relationship between the length of the inner conductor 23a-2 and the film thickness.
As the apparatus, a microwave plasma processing apparatus 1a having the structure shown in FIG. 1 was used. The number of bottles to be stored was four.
The internal conductors 23a-2 were prepared with lengths of 30 mm, 170 mm, 260 mm, and 271 mm, respectively. Each length represents the length of the portion “L” shown in FIG. 1, that is, the length from the top surface 11-4 of the chamber 11a to the tip of the internal conductor 23a-2. Further, “271 mm” is the length when the tip of the internal conductor 23a-2 contacts the upper surface 13-1 of the base 13a.

  Each time the inner conductors 23a-2 having different lengths were attached, the film forming process of the bottle was performed. Under the operation procedure of the microwave plasma processing apparatus described above, a reactive gas (oxygen 30 sccm, hexamethyldisiloxane (HMDSO) 3 sccm) necessary for vapor deposition is introduced, and a predetermined pressure (in-bottle vacuum 8 Pa or less, processing) When the room (outside of the bottle) had a degree of vacuum of about 3000 Pa, a microwave of 2.45 GHz was introduced and plasma deposition was performed for 6 seconds.

And after the film-forming process, the top-plate part 11a-2 of the chamber 11a was opened, the bottle was taken out, and the film thickness was measured for every predetermined height from the bottom part of the bottle.
Measurements were made at 15 mm, 45 mm, 75 mm, 105 mm, 135 mm, and 165 mm heights from the bottom of the PET bottle, and the Si amount in the film at each measurement site was measured using a fluorescent X-ray apparatus manufactured by Rigaku Corporation. The film thickness distribution was measured by converting the calibration curve into the film thickness.

The measurement results are shown in FIG.
In the figure, the horizontal axis represents the height [mm] from the bottom of the bottle, and the vertical axis represents the film thickness [nm].
As shown in the figure, it was found that the longer the inner conductor 23a-2 is, the longer the film thickness of the bottle is. In particular, the increase in film thickness was significant at the top of the bottle.

Further, when the length of the inner conductor 23a-2 was 271 mm, that is, when the tip of the inner conductor 23a-2 was in contact with the upper surface 13-1 of the base 13a, the film thickness was the thickest.
Furthermore, when the tip of the inner conductor 23a-2 is positioned below the bottom surface of the bottle, specifically, when the length of the inner conductor 23a-2 is 270 mm to 90 mm (in FIG. 8, 260 mm and 170 mm). In the case), a thin film having a sufficient film thickness was formed over the entire bottle.

On the other hand, when the tip of the inner conductor 23a-2 is located above the bottom surface of the bottle, specifically, when the length of the inner conductor 23a-2 is 90 mm or less (in FIG. 8, the case of 30 mm). ), A thin film was formed at the bottom of the bottle, but almost no thin film was formed at the top.
The experiment was also performed on the inner conductor 23a-2 having a length of 20 mm under the above-described conditions. However, in this case, no plasma emission occurred and no film was formed.

The inventor also analyzed the relationship between the length of the inner conductor 23a-2 and the electric field distribution inside the chamber 11a.
The analysis means that a dedicated simulation program is started by a personal computer, a predetermined condition is input, and the electric field distribution inside the chamber 11a is examined.

The analysis conditions were as follows.
(conditions)
Length of inner conductor 23a-2: 20mm, 80mm, 140mm, 200mm, 260mm, 271mm
Inner diameter of chamber 11a: 80φ
The height of the chamber 11a: 271 mm
Length of gas nozzle 12: 185mm
Pitch between each gas nozzle 12: 80 mm
Number of bottles: 4
In addition, between each of 20 mm, 80 mm, 140 mm, 200 mm, and 260 mm is λ / 2 (≈60 mm).

The result of this analysis is shown in FIG.
As shown in the figure, a strong electric field portion was generated every λ / 2 (≈60 mm) of the length of the internal conductor 23a-2.
When the tip of the inner conductor 23a-2 is positioned below the tip of the gas nozzle 12, for example, when the length of the inner conductor 23a-2 is 260 mm or 200 mm, around the inner conductor 23a-2, A strong electric field was generated. In addition, as the length of the inner conductor 23a-2 is longer, the electric field around the gas nozzle 12 tends to become stronger. Finally, when the length of the inner conductor 23a-2 is 271 mm (the inner conductor 23a-2 When the tip is in contact with the upper surface 13-1 of the base 13a), the electric field around the gas nozzle 12 was strong. In particular, since the electric field concentration in the vicinity of the base of the gas nozzle 12 became strong, the plasma emission in the entire bottle was confirmed.

  Furthermore, when the tip of the inner conductor 23a-2 is located above the tip of the gas nozzle 12, for example, when the length of the inner conductor 23a-2 is 80 mm or 20 mm, the periphery of the gas nozzle 12 is almost strong. The generation of the electric field is no longer seen. For this reason, at 80 mm, light was emitted only from the bottom of the bottle, and at 20 mm, plasma emission was not possible.

(Example 2)
The inventor analyzed the relationship between the inner diameter of the chamber 11a and the electric field distribution.
The analysis conditions were as follows.
(conditions)
Inner diameter of chamber 11a: 80φ, 70φ, 60φ
The height of the chamber 11a: 271 mm
Length of gas nozzle 12: 185mm
Pitch between each gas nozzle 12: 80 mm
Number of bottles: 4
Length of inner conductor 23a-2: 271mm

Under this condition, the electric field distribution inside the chamber 11a was analyzed for each of the diameters 80φ, 70φ, and 60φ of the inner wall of the chamber 11a.
The results are shown in FIGS. 10 (i-1) to (i-3).
10 (i-1) to (i-3) are analysis diagrams showing the electric field distribution inside the chamber 11a when performed under the above-described conditions.

As shown in FIGS. 10 (i-1) to (i-3), when the inner diameter D decreases, the electric field concentrates on the inner conductor 23a-2, and a strong electric field portion does not occur around the gas nozzle 12. It was.
On the other hand, when the inner diameter D increases, the electric field concentrates around the gas nozzle 12.
For this reason, it has been found that the larger inner diameter D is better. However, when the inner diameter D is increased more than necessary, the electric field does not concentrate around the gas nozzle 12 and the film thickness distribution is non-uniform due to plasma emission failure. Become.

[Second Embodiment]
Next, a second embodiment of the microwave plasma processing apparatus and the microwave plasma processing method of the present invention will be described with reference to FIG.
This figure is a front sectional view showing the configuration of the microwave plasma processing apparatus of the present embodiment.
The present embodiment is different from the first embodiment in the position of the waveguide portion with respect to the chamber. That is, in the first embodiment, the waveguide portion is attached above the top plate portion of the chamber, whereas in this embodiment, the waveguide portion is attached below the base. Other components are the same as those in the first embodiment.
Therefore, in FIG. 11, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

(1) Basic Configuration As shown in FIG. 11, the microwave plasma processing apparatus 1b includes a processing chamber 10b and a waveguide portion 20b.
Here, the processing chamber 10b includes a chamber 11b, a gas nozzle 12, and a base 13b.
The top plate portion 11b-2 is placed on the upper surface of the chamber 11b. The top plate portion 11b-2 does not have a through-hole that is formed in the top plate portion 11a-2 of the first embodiment. This is because the inner conductor 23b-2 of the coaxial waveguide 23b passes from the base 13b, not from the top plate portion 11b-2.

A through hole (center through hole) 13-4 is formed in the center of the base 13b in the vertical direction. The inner conductor 23b-2 is passed through the central through hole 13-4.
The base 13b has a plurality of through holes 13-2 in addition to the central through hole 13-4. These through-holes 13-2 are drilled at rotationally symmetric positions with the central through-hole 13-4 as the axis of symmetry. The gas nozzle 12 is passed through these through holes 13-2.

The waveguide 20b has a hollow waveguide 21, a coaxial waveguide converter 22, and a coaxial waveguide 23b.
The coaxial waveguide 23b connects the coaxial waveguide converter 22 and the base 13b, and the microwave transmitted from the coaxial waveguide converter 22 is transmitted through the central through hole of the base 13b. It supplies to the inside of the chamber 11b via 13-4.
The coaxial waveguide 23b has an outer conductor 23b-1 and an inner conductor 23b-2.
The outer conductor 23b-1 is formed in a cylindrical shape, and connects between the coaxial waveguide side connection portion 22-2 of the coaxial waveguide converter 22 and the base 13b. Thereby, the inner hollow part of the coaxial waveguide converter 22 and the inner hollow part of the chamber 11b communicate with each other through the inner hollow part of the outer conductor 23b-1 and the central through hole 13-4 of the base 13b.

  The inner conductor 23b-2 is formed in a rod shape or a cylindrical shape, and is disposed coaxially with the outer conductor 23b-1 inside the outer conductor 23b-1. Further, one end of the inner conductor 23b-2 is connected to the inner wall surface of the coaxial waveguide converter 22, and the other end passes through the central through hole 13-4 of the base 13b and passes through the inside of the chamber 11b. Has reached.

As described above, the microwave plasma processing apparatus 1b of the present embodiment attaches the coaxial waveguide 23b to the bottom of the base 13b, and coaxially guides it from the central through hole 13-4 of the base 13b toward the inside of the chamber 11b. The inner conductor 23b-2 of the wave tube 23b is passed.
Thereby, the electric field strength around the gas nozzle 12 can be increased, and a high-quality and homogeneous thin film can be formed inside the bottle.

Prior to the filing of the present application, the microwave plasma processing apparatus has passed a gas nozzle through a through hole formed in the center of the base. And the internal conductor was passed through the through-hole drilled in the center of the top plate part.
With this configuration, a strong electric field strength cannot be generated around the gas nozzle, and a desired film forming process cannot be performed.
Therefore, in the microwave plasma processing apparatus 1b of the present embodiment, the position of the gas nozzle 12 is aligned with the central axis 11-1 of the chamber 11b so that the central axis of the gas nozzle 12 and the central axis of the internal conductor 23b-2 are not aligned. Arranged from the position. Thereby, since the gas nozzle 12 and the bottle are no longer arranged at the center of the base 13b, the internal conductor 23b-2 can be arranged here.
Therefore, the inner conductor 23b-2 and the gas nozzle 12 are arranged closer to each other, and the inner conductor 23b-2 is also present near the base of the gas nozzle 12, so that a strong electric field strength is generated around the gas nozzle 12. Can be generated.

(2) Detailed Configuration Next, a detailed configuration of the microwave plasma processing apparatus will be described.
(2-1) Length of Internal Conductor As shown in FIG. 11, the internal conductor 23b-2 and the gas nozzle 12 are arranged so as to be shifted so that their central axes are not positioned on a straight line. Here, since the internal conductor 23b-2 is disposed on the central axis 11-1 of the chamber 11b, the gas nozzle 12 is disposed at a position shifted from the central axis 11-1. Thereby, since the gas nozzle 12 and the bottle do not exist in the center of the base 13b, the internal conductor 23b-2 can be arranged in the center of the base 13b.
The length L of the internal conductor 23b-2 is preferably set to the length determined by the following equation, as in the first embodiment.
L = (λ / 2) × n + α (Formula 3)
Note that λ is a microwave wavelength in vacuum, n is an integer of 1 or more, and α is a length to be added in design.
As will be described later in the embodiment, a strong electric field portion is generated every λ / 2 (≈60 mm) around the inner conductor 23b-2.

  Furthermore, the positional relationship between the tip of the internal conductor 23b-2 and the tip of the gas nozzle 12 is important, and it is desirable that the tip of the internal conductor 23b-2 be at least near or above the tip of the gas nozzle 12. In particular, when the internal conductor 23b-2 is lengthened until the tip of the internal conductor 23b-2 contacts the top surface 11-4 of the chamber 11b, the electric field around the gas nozzle 12 becomes strong. Moreover, since the electric field concentration near the base of the gas nozzle 12 becomes strong, plasma is generated in the entire bottle, and in particular, the thickness of the upper part of the bottle increases.

On the other hand, when the tip of the inner conductor 23b-2 is located below the tip of the gas nozzle 12, the electric field around the gas nozzle 12 and the electric field concentration near the root are weakened, and plasma does not emit light around the bottle. Therefore, no film is formed on the upper part of the bottle.
In addition, the inventor experimented about the relationship between the length of this internal conductor 23b-2, and a film thickness. The contents of this experiment will be described later in the following (3) Example.
Moreover, since the microwave plasma processing method of this embodiment is the same as the microwave plasma processing method of 1st embodiment, description here is abbreviate | omitted.

(3) Example The inventor analyzed the length of the internal conductor 23b-2.
(conditions)
Length of internal conductor 23b-2: 30mm, 90mm, 150mm, 162mm, 210mm, 271mm
Inner diameter of chamber 11b: 80φ
The height of the chamber 11b: 271 mm
Length of gas nozzle 12: 185mm
Pitch between each gas nozzle 12: 80 mm
Number of bottles: 4
In addition, between each of 30 mm, 90 mm, 150 mm, 210 mm, and 271 mm is λ / 2 (≈60 mm). 162 mm is the case where the tip of the internal conductor 23b-2 and the tip of the gas nozzle 12 are at the same height.

The result of this analysis is shown in FIG.
From the analysis results shown in FIG.
When the tip of the internal conductor 23b-2 inserted from the central through hole 13-4 of the base 13b is brought into contact with the top surface 11-4 of the chamber 11b (in the case of “271 mm” in FIG. 12), the periphery of the gas nozzle 12 The electric field strength of became stronger. In particular, the electric field concentration at the base of the gas nozzle 12 became stronger.
Further, as far as this embodiment is concerned, even when the tip of the gas nozzle 12 and the tip of the internal conductor 23b-2 are at the same height from the bottom (in the case of "162 mm" in the figure), the internal conductor 23b- Under the influence of the electric field concentration of 2, the electric field concentration around and at the base of the gas nozzle 12 became stronger. This is presumably because the electric field was exchanged between the tip of the gas nozzle 12 and the tip of the internal conductor 23b-2.
Thus, when the internal conductor 23b-2 was introduced from the center of the bottom surface of the chamber 11b, it was advantageous to concentrate the electric field at the base of the gas nozzle 12.
However, when the tip of the inner conductor 23b-2 is positioned below the tip of the gas nozzle 12, the electric field concentration around the gas nozzle 12 is weakened.

From the results of the first embodiment and the second embodiment, when the waveguide unit is attached above the top plate of the chamber, the gas nozzle is installed so that the bottle is placed upside down on the upper surface of the base inside the chamber. However, even if the gas nozzle is installed so that the bottle is placed on the top surface, it can be seen that the tip of the inner conductor is preferably located below the tip of the gas nozzle.
Similarly, when the waveguide is attached below the base, the tip of the inner conductor should be positioned above the tip of the gas nozzle, regardless of the position of the gas nozzle. The reaching length is preferred.

[Third embodiment]
Next, a third embodiment of the microwave plasma processing apparatus and the microwave plasma processing method of the present invention will be described with reference to FIG.
This figure is a front sectional view showing the configuration of the microwave plasma processing apparatus of the present embodiment.
This embodiment differs from the first embodiment in the configuration inside the chamber. That is, in the first embodiment, the bottle is placed upside down on the upper surface of the base inside the chamber, whereas in this embodiment, the bottle is engaged not only with the upper surface of the base inside the chamber but also with the top surface. Drooped. Other components are the same as those in the first embodiment.
Therefore, in FIG. 13, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 13, the microwave plasma processing apparatus 1c includes a processing chamber 10c and a waveguide 20c.
Here, the processing chamber 10c includes a chamber 11c, gas nozzles 12 (12-1, 12-2), and a base 13c.
A top plate portion 11c-2 is placed on the upper surface of the chamber 11c. A through hole (central through hole) 11c-3 is formed in the center of the top plate portion 11c-2. The inner conductor 23c-2 of the coaxial waveguide 23c is passed through the central through hole 11c-3.
In addition to the central through hole 11c-3, a plurality of through holes 11-7 are formed in the top plate portion 11c-2. These through holes 11-7 are formed at positions that are rotationally symmetric with respect to the central through hole 11c-3. A gas nozzle 12-2 is passed through these through holes 11-7.

The gas nozzle 12 is erected through the through-hole 13-2 drilled in the base 13c (gas nozzle 12-1) and erected through the through-hole 11-7 of the top plate portion 11c-2 ( Gas nozzle 12-2).
There are bottles that are placed in an inverted state on the upper surface 13-1 of the base 13c, and bottles that are screwed into the top surface 11-4 of the top plate portion 11c-2 to hang down. . These bottles are attached so that the gas nozzles 12-1 and 12-2 are positioned on the central axis. For this reason, the bottle can be attached by the same number as the gas nozzles 12-1 and 12-2 at the maximum.

The arrangement of the gas nozzles 12-1, 12-2 and the bottle can be the same as the arrangement shown in FIGS.
That is, the plurality of gas nozzles 12-1 and 12-2 are arranged at positions shifted from the central axis 11-1 of the chamber 11c. The plurality of gas nozzles 12-1 and 12-2 are arranged in rotational symmetry with the central axis 11-1 of the chamber 11 c as an axis of symmetry.
Further, the plurality of bottles are arranged in rotational symmetry with the central axis 11-1 of the chamber 11c as the axis of symmetry, like the gas nozzles 12-1 and 12-2.

The waveguide section 20c includes a hollow waveguide 21, a coaxial waveguide converter 22, and a coaxial waveguide 23c.
The coaxial waveguide 23c has an outer conductor 23c-1 and an inner conductor 23c-2.
One end of the inner conductor 23c-2 is connected to the inner wall surface of the coaxial waveguide converter 22, and the other end passes through the central through hole 11c-3 of the top plate portion 11c-2, Reached inside.

The length L of the internal conductor 23c-2 is preferably set to the length defined by the following equation, as in the first and second embodiments.
L = (λ / 2) × n + α (Formula 4)
Note that λ is a microwave wavelength in vacuum, n is an integer of 1 or more, and α is a length to be added in design.
As will be described later in the embodiment, a strong electric field portion is generated every λ / 2 (≈60 mm) around the inner conductor 23c-2.

  Furthermore, the positional relationship between the tip of the internal conductor 23c-2 and the tip of the gas nozzle 12-1 is important, and the tip of the internal conductor 23c-2 is at least below the tip of the gas nozzle 12-1 standing on the base 13c. In particular, when the internal conductor 23c-2 is lengthened until the tip of the internal conductor 23c-2 contacts the upper surface 13-1 of the base 13c, the electric field around the gas nozzle 12 is reduced. Become stronger. Moreover, since the electric field concentration near the base of the gas nozzle 12 becomes strong, plasma is generated in the entire bottle, and in particular, the thickness of the upper part of the bottle increases.

On the other hand, when the tip of the inner conductor 23c-2 is located above the tip of the gas nozzle 12-1, the electric field around the gas nozzle 12 and the electric field concentration near the root are weakened, and plasma is emitted around the bottle. Disappear. Therefore, no film is formed on the upper part of the bottle.
In addition, the inventors analyzed the electric field distribution inside the chamber 11c in such a configuration.
(conditions)
Length of inner conductor 23c-2: 542mm
Inner diameter of chamber 11c: 80φ
The height of the chamber 11c: 542mm
Length of gas nozzles 12-1, 12-2: 185mm
Pitch between each gas nozzle 12: 80 mm
Number of bottles: 8

The result of this analysis is shown in FIG.
As shown in the figure, when the tip of the internal conductor 23c-2 reaches the upper surface 13-1 of the base 13c, the electric field around the gas nozzles 12-1 and 12-2 was strong. In particular, since the electric field concentration in the vicinity of the base of both the gas nozzles 12-1 and 12-2 became strong, plasma was emitted from the entire bottle.

  In addition, since the microwave plasma processing method of this embodiment is the same as the microwave plasma processing method of 1st embodiment, description here is abbreviate | omitted.

  As described above, according to the microwave plasma processing apparatus and the microwave plasma processing method of the present embodiment, since the central axis of the inner conductor of the coaxial waveguide and the central axis of the gas nozzle are shifted, the inner conductor Can be extended to a position below the tip of the gas nozzle. Thereby, the microwave propagates in the height direction of the bottle even after the plasma emission, and the plasma emission in the whole bottle becomes possible.

Further, by arranging the gas nozzle and the bottle on the circumference centering on the inner conductor, it becomes possible to simultaneously perform the film forming process on a plurality of bottles with a single microwave power source.
Furthermore, it is possible to form a film on a larger number of bottles by allowing the bottles to be mounted so as to hang on the top surface of the chamber as well as being placed on the upper surface of the base.

The preferred embodiments of the microwave plasma processing apparatus and the microwave plasma processing method of the present invention have been described above. However, the microwave plasma processing apparatus and the microwave plasma processing method of the present invention are limited only to the above-described embodiments. It goes without saying that various modifications can be made within the scope of the present invention.
For example, in each of the above-described embodiments, the bottle is cited as the processing target of the microwave plasma processing apparatus. However, the processing target is not limited to the bottle, and various plastic containers may be the target.
The bottle includes, for example, a biaxial stretch blow molded bottle formed from polyester such as polyethylene terephthalate.

  INDUSTRIAL APPLICABILITY The present invention can be used for an apparatus or an apparatus that introduces a microwave into a chamber by a coaxial waveguide and executes a predetermined process on a processing target.

DESCRIPTION OF SYMBOLS 1a-1c Microwave plasma processing apparatus 10a-10c Processing chamber 11a-11c Chamber 11a-2-11c-2 Top plate part 11a-3 Through-hole 11-4 Top surface 11-5 Inner wall 11-6 Core 12 (12- 1, 12-2) Gas nozzles 13a to 13c Base 13-1 Upper surface 20a to 20c Waveguide portion 21 Hollow waveguide 22 Coaxial waveguide converter 23a to 23c Coaxial waveguide 23a-2 to 23c-2 Inner conductor

Claims (10)

A coaxial waveguide for supplying microwaves to the chamber;
A gas nozzle for supplying a raw material gas into the chamber;
A base on which the chamber is placed;
The coaxial waveguide has an inner conductor;
The inner conductor is inserted into the chamber through a through hole in the top plate of the chamber;
The gas nozzle is erected in the chamber through the through hole of the base, and is disposed at a position shifted from the central axis of the internal conductor ;
The microwave plasma processing apparatus , wherein a tip of the inner conductor is positioned below a tip of the gas nozzle . The tip of the inner conductor reached the upper surface of the base
The microwave plasma processing apparatus according to claim 1. A coaxial waveguide for supplying microwaves to the chamber;
A gas nozzle for supplying a raw material gas into the chamber;
A base on which the chamber is placed;
The coaxial waveguide has an inner conductor;
The inner conductor is inserted from the through hole of the base toward the inside of the chamber,
The gas nozzle is inserted through the through hole of the base, and is disposed at a position shifted from the central axis of the inner conductor,
The tip of the inner conductor is located at a height close to the tip of the gas nozzle or above the tip of the gas nozzle.
A microwave plasma processing apparatus. The inner conductor had a length reaching the top surface of the chamber
The microwave plasma processing apparatus according to claim 3. Provided with a plurality of gas nozzles
The microwave plasma processing apparatus according to any one of claims 1 to 4, wherein the apparatus is a microwave plasma processing apparatus. The plurality of gas nozzles are rotationally symmetric with respect to the central axis of the inner conductor.
The microwave plasma processing apparatus according to claim 5. A plurality of the gas nozzles
One or more gas nozzles inserted from the through hole of the base toward the inside of the chamber;
One or more gas nozzles inserted from the through hole in the top plate portion of the chamber toward the inside of the chamber.
The microwave plasma processing apparatus according to claim 5 or 6, wherein the apparatus is a microwave plasma processing apparatus. A core was provided on the inner wall of the chamber.
The microwave plasma processing apparatus according to any one of claims 1 to 7, wherein A microwave plasma processing method for performing predetermined processing on an object placed in a chamber,
Supplying a source gas into the chamber from a gas nozzle that is erected inside the chamber through a through-hole of a base on which the chamber is placed, and is disposed at a position displaced from the central axis of the chamber;
An internal conductor that is inserted into the chamber through a through-hole in the top plate portion of the chamber and is disposed on the central axis of the chamber, the tip of which is located below the tip of the gas nozzle And a step of generating a plasma by supplying a microwave into the chamber via a coaxial waveguide having a conductor.
The microwave plasma processing method characterized by the above-mentioned. A microwave plasma processing method for performing predetermined processing on an object placed in a chamber,
Supplying a source gas into the chamber from a gas nozzle that is inserted through a through-hole of a base on which the chamber is placed and disposed at a position displaced from the central axis of the chamber;
The inner conductor is inserted from the through hole of the base toward the inside of the chamber and is disposed on the central axis of the chamber, and the tip is close to the height of the tip of the gas nozzle, or the And a step of generating a plasma by supplying a microwave into the chamber via a coaxial waveguide having the inner conductor positioned above the tip of the gas nozzle.
The microwave plasma processing method characterized by the above-mentioned.