JP2009070735A - Electromagnetic wave plasma generator, its generating method, its surface treatment apparatus, and its surface treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for generating the electromagnetic wave plasma, which is generated with a small negative bias voltage value and is uniformly propagated into a member to be processed having an internal shape with a high aspect ratio like a pipe; and to provide a generator using such a method. <P>SOLUTION: The electromagnetic wave plasma generator includes a chamber 10 having a gas feed section 40, a gas exhaust section 41 and an electromagnetic wave supply section 22, and a bias-applying means 30 for applying a bias voltage to a member being processed 3, and generates the plasma at a hollow part 5 of the member being processed 3. An electromagnetic wave plasma generator 101 is used where the electromagnetic wave supply section 22 is arranged at a position facing the inside of the chamber 10, while the member to be processed 3 is arranged within the chamber 10, and at least one or more plasma guiding means 1 are provided for guiding a generation area of the plasma generated within the chamber 10 toward the inside of the hollow part 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic wave plasma generation apparatus, a generation method thereof, a surface treatment apparatus thereof, and a surface treatment method thereof.

  In recent years, in the semiconductor industry, an environment with an extremely high degree of cleanness has been demanded as the wiring density has been increased. In order to obtain such an environment with a high degree of cleanliness, the surfaces of members such as metal parts and metal pipes constituting the semiconductor manufacturing apparatus are required to be clean. One of the methods for cleaning the surface of members such as metal parts and metal pipes is to use a plasma method. By generating plasma with high density and subjecting the surface of the member to plasma treatment, it can be made clean. Furthermore, a thin film having high corrosion resistance can be formed on the surface of the member by subjecting the surface of the member to plasma treatment together with the reaction gas. Therefore, the needs for the plasma method are increasing.

  In particular, since metal pipes used in semiconductor devices often use corrosive gas, there is a high demand for protecting the inside of the pipes with a corrosion-resistant thin film. However, it has been difficult to form a corrosion-resistant thin film by generating plasma uniformly on the inner surface of the metal pipe. Furthermore, it has been more difficult to uniformly plasma-treat the surface of a member having a complicated shape. Therefore, there has been a demand for means for generating plasma in accordance with the internal shape of such a metal pipe.

  Patent Document 1 discloses an example in which plasma processing is performed on a member to be processed made of a conductive material by controlling plasma using electromagnetic waves. Since this member to be processed has a deep depth and a narrow opening, it has an internal shape with a high aspect ratio. By adjusting the negative bias voltage and the electromagnetic wave of 2.45 GHz even for the member to be processed having such an internal shape, the inner surface plasma is generated and maintained by superimposing the plasma seeds existing along the internal shape. It is possible.

However, there is a problem that the inner surface plasma is not uniform along the depth direction, and the inner surface of the member to be processed cannot be uniformly plasma processed.
Since electromagnetic waves cannot be propagated and entered without being reflected inside the member to be processed, sufficient electromagnetic wave power cannot be introduced into the interior, resulting in non-uniform distribution of electric field strength and non-uniform distribution of inner surface plasma. It is. In addition, when the opposite side of the member to be processed is open, the electromagnetic wave forms a standing wave in the depth direction inside the member to be processed, resulting in a non-uniform distribution of the electric field strength and a non-uniform distribution of the inner surface plasma. This is because.

Furthermore, even if the negative bias voltage is increased, the inner surface plasma may not be completely ignited.
When the negative bias voltage applied to the target gradually increases to reach a certain voltage value, the inner surface plasma is ignited and maintained throughout the member to be processed, but the electromagnetic field is unevenly distributed. In addition, when there is no means for guiding the plasma inside the member to be processed, the electromagnetic wave for generating the inner surface plasma cannot be uniformly propagated and entered inside the member to be processed.
JP 2004-47207 A

  The present invention has been made in view of the above circumstances, and generates electromagnetic wave plasma with a small negative bias voltage value, and uniformly distributes the electromagnetic wave plasma inside a member to be processed having a high aspect ratio internal shape such as a pipe. An object of the present invention is to provide a method of generating electromagnetic wave plasma to be propagated and a generating apparatus therefor.

In order to achieve the above object, the present invention employs the following configuration. That is,
An electromagnetic wave plasma generator according to the present invention includes a chamber provided with a gas supply unit, a gas discharge unit, and an electromagnetic wave supply unit, and bias applying means for applying a bias voltage to a member to be processed, and has at least one opening. An electromagnetic wave plasma generator for generating plasma inside a hollow part of a member to be processed having a hollow part, wherein the electromagnetic wave supply part is arranged at a desired position in the chamber, and the member to be processed is At least one or more plasma guiding means is provided for guiding a plasma generation region generated in the chamber into the hollow portion while being disposed in the chamber.

  In the electromagnetic wave plasma generator of the present invention, it is preferable that the electromagnetic wave supply unit is disposed at a position where the opening of the member to be processed is desired.

  In the electromagnetic wave plasma generator of the present invention, it is preferable that the plasma induction means is a linear conductor disposed in the hollow portion of the member to be processed.

  In the electromagnetic wave plasma generator of the present invention, it is preferable that the plasma induction means is an insulating thin film applied to the outer surface of the member to be processed.

  In the electromagnetic wave plasma generator of the present invention, the insulating thin film is preferably a silica coat.

  In the electromagnetic wave plasma generator of the present invention, it is preferable that the linear conductor is disposed coaxially with the central axis of the hollow portion.

  In the electromagnetic wave plasma generator of the present invention, when another opening is provided in the hollow portion, one end side of the linear conductor is disposed inside the hollow portion, and the linear conductor The other end side is disposed so as to protrude from the other opening, and the protruding length is an integral multiple of 1/4 of the wavelength of the electromagnetic wave propagating from the inside of the member to be processed to the outside. Is preferred.

  In the electromagnetic wave plasma generator of the present invention, when another opening is provided in the hollow portion, it is preferable that an electromagnetic wave absorbing member is disposed in the other opening.

  In the electromagnetic wave plasma generator of the present invention, the electromagnetic wave supply unit is connected to the dielectric for supplying the electromagnetic wave into the chamber via the dielectric, and the dielectric disposed at a desired position in the chamber. Preferably, it is made of a coaxial cable or a waveguide.

  In the electromagnetic wave plasma generator of the present invention, the linear conductor is preferably connected to the dielectric.

  In the electromagnetic wave plasma generator of the present invention, the dielectric is provided inside a flange portion disposed at a desired position in the chamber, and the flange portion passes through the dielectric and is coaxial with the flange portion. A coaxial inner conductor forming a line is provided, the linear conductor is connected to one end of the coaxial inner conductor, and a coaxial cable or waveguide is connected to the other end of the coaxial inner conductor. It is preferable.

  The electromagnetic wave plasma generation method of the present invention includes at least one opening using a chamber provided with a gas supply unit, a gas discharge unit, and an electromagnetic wave supply unit, and bias applying means for applying a bias voltage to a member to be processed. An electromagnetic wave plasma generation method for generating electromagnetic wave plasma inside a hollow part of a member to be processed having a hollow part, wherein the electromagnetic wave supply part is disposed at a desired position in the chamber, and the member to be processed is the chamber And a plasma generation region generated in the chamber is guided into the hollow portion by plasma guiding means.

  An electromagnetic wave plasma surface treatment apparatus according to the present invention is characterized in that the electromagnetic wave plasma generator according to any one of the preceding aspects is provided with a supply means for a reactive gas for surface treatment of nitriding, cleaning or plasma CVD. .

  The electromagnetic wave plasma surface treatment method of the present invention is the electromagnetic wave plasma generation method described above, wherein an electromagnetic wave plasma is generated while supplying a reactive gas for surface treatment of nitridation, cleaning or plasma CVD into the chamber, and a member to be treated It is characterized by surface-treating the inner wall surface.

  According to the above configuration, an electromagnetic wave plasma generation method of generating electromagnetic wave plasma with a small negative bias voltage value and uniformly propagating the electromagnetic wave plasma inside a member to be processed having a high aspect ratio internal shape such as a pipe, and The generating device can be provided.

Hereinafter, modes for carrying out the present invention will be described.
(Embodiment 1)
FIG. 1 is a schematic cross-sectional view showing an example of an electromagnetic wave plasma generator according to an embodiment of the present invention.
An electromagnetic wave plasma generator 101 according to an embodiment of the present invention includes a member to be processed 3 and a linear conductor 7 in a chamber 10 provided with a gas supply unit 40, a gas discharge unit 41, and an electromagnetic wave supply unit 22. The plasma induction means 1 is provided.
The electromagnetic wave supply unit 22 is provided with a dielectric 51.

  The member to be processed 3 is a pipe-like member to be processed 18 having a hollow portion 5 that is opened, and is disposed so as to be galvanically insulated from the chamber via a dielectric 51. In addition, as a material of the to-be-processed member 3, what is necessary is just an electroconductive material, For example, a metal or an alloy material etc. can be mentioned, SUS etc. can be used.

The linear conductor 7 has a longitudinal direction parallel to the longitudinal direction of the pipe-shaped member 18 and is arranged inside the hollow portion 5 without being in contact with the inner wall surface 5c of the hollow portion 5 that is opened. ing.
Thus, by arranging the linear conductor 7 in accordance with the internal shape of the pipe-shaped member 18, electromagnetic wave plasma can be formed in accordance with the internal shape of the pipe-shaped member 18. The inner wall surface 5c of the hollow part 5 of the pipe-shaped member 18 can be plasma-treated.
In addition, when the linear conductor 7 is in contact with the inner wall surface 5c, the distribution of electromagnetic wave plasma is not uniform, which is not preferable.
In addition, as a material of the linear conductor 7, a tungsten wire (W line) etc. can be used, for example.

Moreover, the linear conductor 7 is arrange | positioned so that it may become a coaxial structure inside the hollow part 5 of the pipe-shaped to-be-processed member 18. FIG.
The coaxial structure refers to a structure in which the linear conductor 7 is disposed at the position serving as the central axis of the hollow portion 5. By arranging in this manner, reflection of electromagnetic waves that propagate and enter the hollow portion 5 is reduced. The electromagnetic wave plasma can be uniformly distributed inside the pipe-shaped member 18.

Further, the other end side 7b of the linear conductor 7 is ¼ of the wavelength of the electromagnetic wave radiated from the electromagnetic wave supply unit 22 to the outside from the other opening 5b of the hollow part 5 of the pipe-shaped member 18. The antenna unit 2 is arranged so as to protrude by a length that is an integral multiple of.
When the antenna portion 2 is arranged so as to protrude by a length that is an integral multiple of 1/4 of the wavelength of the electromagnetic wave propagating from the inside of the member to be processed to the outside, another opening portion 5b of the hollow portion 5 is provided. Reflection does not occur when electromagnetic waves reach. This is because the electromagnetic wave propagating through the hollow portion 5 is completely radiated out of the hollow portion 5. As a result, electromagnetic waves can be propagated uniformly and longer than before along the central axis direction of the hollow portion 5, and electromagnetic wave plasma can be generated uniformly.

  Even when the antenna unit 2 is not provided, the same effect as that when the antenna unit 2 is provided can be obtained when the other end side 7b of the linear conductor 7 is extended sufficiently long. Specifically, when the electromagnetic wave is propagated along the linear conductor 7 for a long time, the linear conductor 7 has a resistance, so that it can be completely absorbed while the power of the electromagnetic wave is attenuated, Reflection does not occur at the other opening 5b of the hollow portion 5, and the electromagnetic wave can be completely radiated to the outside substantially. As a result, the electromagnetic wave can be prevented from forming a standing wave along the longitudinal direction of the hollow portion 5, and the electromagnetic wave plasma can be generated uniformly.

The pipe-shaped target member 18 is connected to a bias applying means 30 disposed outside the chamber 10 by a wiring 32. By operating the bias applying means 30, a negative bias voltage can be applied to the pipe-shaped member 18. Therefore, by operating the bias applying means 30, a negative bias can be applied to the pipe-shaped member 18, and the generated electromagnetic wave plasma can be uniformly distributed in the depth direction of the pipe-shaped member 18.
In particular, an electromagnetic wave radiated from the electromagnetic wave supply unit 22 toward the pipe-shaped member 18 is directed from the opening 5a of the hollow portion 5 to another opening 5b along the boundary between the sheath region and the plasma phase. By applying a negative bias voltage to the pipe-shaped member 18 during propagation, the uniformity of the electromagnetic wave plasma generated along the electromagnetic wave can be enhanced.

The electromagnetic wave supply unit 22 includes a dielectric 51 disposed at a desired position in the chamber 10, and a coaxial cable 60 connected to the dielectric 51 in order to supply an electromagnetic wave into the chamber 10 via the dielectric 51. Has been.
The dielectric 51 is configured to be inserted into a hole 11 provided in the chamber 10. A seal portion 55 is inserted between the dielectric 51 and the chamber 10, and the dielectric 51 is fixed to the chamber 10 by the support portion 64, whereby the decompressed state in the chamber 10 is maintained. .

The coaxial cable 60 is connected to the electromagnetic wave supply source 20. The coaxial cable 60 includes a linear inner conductor 62, an insulator surrounding the inner conductor 62, and an outer conductor 63 surrounding the insulator. The electromagnetic wave generated from the electromagnetic wave supply source 20 propagates between the inner conductor portion 62 and the outer conductor portion 63 in the coaxial cable 60, and the tip of the external antenna portion 57 connected to the coaxial cable 60 by the connector portion 53. Therefore, the pipe-shaped workpiece 18 is radiated through the dielectric 51.
A waveguide may be used instead of the coaxial cable 60.

Since the electromagnetic wave supply unit 22 includes a dielectric 51 made of a dielectric material that hardly absorbs electromagnetic waves, the electromagnetic wave supply unit 22 is directed toward the member 3 to be processed disposed in the chamber 10 in a reduced pressure state. Electromagnetic waves can be propagated without attenuating power.
In addition, as a material of the dielectric 51, quartz glass etc. can be mentioned.

Further, the gas concentration can be adjusted by adjusting the valves of the gas supply port 40 and the gas discharge port 41 after the inside of the chamber 10 is depressurized.
Further, the gas supply unit 40 is provided with a reaction gas supply unit 42 for nitriding, cleaning, or plasma CVD surface treatment so that a reaction gas for nitriding, cleaning, or plasma CVD can be supplied into the chamber 10. Examples of the reactive gas for plasma CVD include SiH ₄ and O ₂ , tetraethoxysilane (TEOS) and O _{3, and the} like. When these reaction gases are used, plasma can be generated inside the hollow portion 5 in which the pipe-shaped member 18 is opened, and a thin film can be formed on the inner wall surface 5c by the principle of plasma CVD. . For example, a SiO ₂ or diamond-like carbon (DLC) film can be formed.
In addition, when an inert gas such as Ar is used, the inner wall surface 5c of the hollow portion 5 of the pipe-shaped member 18 can be cleaned by plasma surface treatment.

(Embodiment 2)
FIG. 2 is a schematic cross-sectional view showing another example of the electromagnetic wave plasma generator according to the embodiment of the present invention.
The electromagnetic wave plasma generator 102 according to the embodiment of the present invention is an electromagnetic wave absorber made of a ceramic cloth, instead of providing the antenna part 2 on the other end 7b of the linear conductor 7 used as the plasma guiding means 1. The structure is the same as that of the electromagnetic wave plasma generator 101 shown in FIG. 1 except that the member 70 is disposed on the other opening 5b side of the hollow portion 5 of the pipe-shaped member 18 to be processed. In addition, about the member same as Embodiment 1, it attaches | subjects and shows the same code | symbol.

When the electromagnetic wave absorbing member 70 is disposed in the other opening 5b of the hollow portion 5 of the pipe-shaped member 18, the electromagnetic wave is absorbed by the electromagnetic wave absorbing member 70, and thus the other opening 5 b of the hollow portion 5. When electromagnetic waves reach the antenna, no reflection occurs, it is possible to prevent a standing wave from being formed, only a traveling wave can be formed, and an effect similar to the case where the antenna unit 2 is provided can be obtained.
As a material of the electromagnetic wave absorbing member 70, carbon, C / C composite, or the like can be used in addition to ceramic cloth.
In FIG. 2, the electromagnetic wave absorbing member 70 is disposed above a space from another opening 5 b of the hollow portion 5. However, the electromagnetic wave absorbing member 70 may be disposed in contact with the opening 5 b.
In the embodiment of the present invention, the other end portion 7b of the linear conductor 7 is not the antenna portion 2, but the other end portion 7b of the linear conductor 7 is the antenna portion 2, Thus, the electromagnetic wave absorbing member 70 may be disposed. This is because both have the same effect of preventing reflection of electromagnetic waves.

(Embodiment 3)
FIG. 3 is a schematic cross-sectional view showing still another example of the electromagnetic wave plasma generator according to the embodiment of the present invention.
The electromagnetic wave plasma generating apparatus 103 according to the embodiment of the present invention includes a linear conductor 7 as the plasma guiding means 1 and an insulating thin film 12 formed on the outer surface 18c of the pipe-shaped member 18 to be processed. The configuration is the same as that of the electromagnetic wave plasma generator 101 shown in FIG. In addition, about the member same as Embodiment 1, it attaches | subjects and shows the same code | symbol.

When the insulating thin film 12 is provided on the outer surface 18c of the pipe-shaped member 18 to be processed, since no direct current bias is applied to the plasma sheath in contact with the insulating thin film 12, electromagnetic waves are not propagated along the outer surface 18c. Plasma cannot be formed on the insulating thin film 12. Therefore, the electromagnetic wave is substantially absorbed only inside the pipe-shaped member 18. Therefore, compared with the case where the insulating thin film 12 is not provided, the density of the plasma formed inside the pipe-shaped member 18 can be increased.
Examples of the material for the insulating thin film 12 include silica. For example, a thin film made of a silica coating layer is formed on the outer surface 18 c of the pipe-shaped member 18 by a CVD method or the like to form the insulating thin film 12.

(Embodiment 4)
FIG. 4 is a schematic cross-sectional view showing still another example of the electromagnetic wave plasma generator according to the embodiment of the present invention.
The electromagnetic wave plasma generating apparatus 104 according to the embodiment of the present invention is the electromagnetic wave plasma shown in FIG. 1 except that two linear conductors 7 connected to the ground part 14 are used as the plasma guiding means 1. The configuration is the same as that of the generator 101. Further, a valve-shaped member 19 is used as the member 3 to be processed. In addition, about the member same as Embodiment 1, it attaches | subjects and shows the same code | symbol.

  In the valve-shaped member 19, the hollow portion 5 is branched at the branch portion 15, and is bent in opposite directions in the horizontal direction. The other openings 5 b of the hollow portion 5 are sub-hollow portions 16 and 17. By providing a mechanism that opens and closes the branch portion 15 (not shown), the flow of fluid such as gas and water flowing in from the sub hollow portions 16 and 17 can be controlled.

As shown in FIG. 4, the valve-shaped member 19 is disposed with the opening 5 a of the hollow portion 5 facing the electromagnetic wave supply unit 22.
In the sub hollow portion 16, the one end side 7 a of the linear conductor 7 has a longitudinal direction parallel to the longitudinal direction of the sub hollow portion 16 and is not in contact with the inner wall surface 16 c of the sub hollow portion 16. These are disposed inside the sub-hollow part 16 and arranged so as to have a coaxial structure.
Further, the other end 7b of the linear conductor 7 is a length that is an integral multiple of 1/4 of the wavelength of the electromagnetic wave radiated from the electromagnetic wave supply unit 22 to the outside from the sub-hollow part 16 of the valve-shaped member 19. The antenna unit 2 is arranged so as to protrude.
Further, the antenna unit 2 is connected to the ground unit 14.
The other of the two linear conductors 7 is also arranged in the sub-hollow portion 17 with the same configuration.

An electromagnetic wave radiated from the electromagnetic wave supply unit 22 toward the valve-shaped member 19 enters from the opening 5 a of the hollow portion 5. The incident electromagnetic wave is branched into the sub-hollow portions 16 and 17 at the branching portion 15, and along the plasma guiding means 1 composed of the linear conductors 7 disposed inside the sub-hollow portions 16 and 17, a valve shape. It is emitted outside the member 19 to be processed. Along with this electromagnetic wave, the electromagnetic wave plasma is also formed along the internal shape of the hollow portion 5 and the sub hollow portions 16 and 17.
As described above, even if the valve-shaped member 19 has a complicated shape, the electromagnetic wave plasma can be formed along the internal shape by using the plasma guiding means 1 made of the linear conductor 7. The plasma surface treatment of the inner wall surfaces 16c and 17c can be performed.

  In the electromagnetic wave plasma generation method of the present embodiment, an example of the valve-shaped member 19 in which another opening 5b of the hollow portion 5 is formed as two sub-hollow portions 16 and 17 is shown. Even in the case of a member to be processed in which a plurality of sub-hollow parts exist in another opening 5b, electromagnetic waves can be transmitted from the opening 5a of the hollow part 5 by introducing the linear conductor 7 into each sub-hollow part. It can guide to the sub hollow part provided in another opening part 5b, and can plasma-process the internal surface of a sub hollow part easily and uniformly.

(Embodiment 5)
FIG. 5 is a schematic cross-sectional view showing still another example of the electromagnetic wave plasma generator according to the embodiment of the present invention.
The electromagnetic wave plasma generator 105 according to the embodiment of the present invention uses the pipe-shaped member 18 as the member to be processed 3 and the electromagnetic wave plasma shown in FIG. The configuration is the same as that of the generator 101. Further, the same members as those of the first embodiment are indicated by the same reference numerals.

The electromagnetic wave supply unit 22 is configured by inserting a flange portion 50 into a hole portion 11 provided in the chamber 10. Since the flange portion 50 is inserted into the chamber 10 without any gap and measures are taken to prevent vacuum leakage, the decompressed state in the chamber 10 is maintained.
Moreover, the pipe-shaped to-be-processed member 18 is arrange | positioned on the flange part 50 through the insulating ring part 56, and electrical insulation is ensured.

  The flange portion 50 is formed by surrounding a coaxial inner conductor portion 59 with a dielectric 51 and further surrounding the dielectric 51 with an outer casing of SUS. Further, the coaxial cable 60 is formed such that the inner conductor portion 62 is surrounded by an insulator and the insulator is surrounded by the outer conductor portion 63. The coaxial cable 60 is connected to the electromagnetic wave supply source 20. A coaxial cable 60 is connected to the outside of the chamber 10 of the flange portion 50, and the coaxial inner conductor portion 59 of the flange portion 50 and the inner conductor portion 62 of the coaxial cable 60 are connected. Further, one end side 7 a of the linear conductor 7 is connected to the coaxial inner conductor portion 59 on the inside of the chamber 10 of the flange portion 50.

  The flange portion 50 is provided with a coaxial inner conductor portion 59 through the dielectric 51. In other words, the dielectric 51 is provided between the flange portion 50 and the coaxial inner conductor portion 59, and a direct current can flow between the inner conductor portion 62 of the coaxial cable 60 and the plasma induction means 1. It has become. The electromagnetic wave generated by the electromagnetic wave supply source 20 propagates between the inner conductor portion 62 and the outer conductor portion 63 of the coaxial cable 60 and is propagated to the dielectric 51 inside the flange portion 50, and from there, a linear conductor 7 and is radiated into the hollow portion 5 of the pipe-shaped member 18.

The electromagnetic wave radiated in this way propagates inside the hollow portion 5 coaxially with the linear conductor 7. Further, since the antenna portion 2 is provided in the other opening 5 b of the hollow portion 5, it is radiated to the outside of the hollow portion 5 without being reflected by the other opening 5 b of the hollow portion 5. For this reason, an electromagnetic wave can be formed uniformly along the internal shape of the hollow part of the pipe-shaped member 18, and an electromagnetic wave plasma can be formed uniformly along the electromagnetic wave.
A waveguide may be used instead of the coaxial cable 60.

  The linear conductor 7 is preferably connected to the dielectric 51 inside the flange portion 50. The linear conductor 7 is disposed on the central axis of the hollow portion 5 of the pipe-shaped member 18 and also disposed on the central axis of the electromagnetic wave supply unit 22, so that electromagnetic waves can be more uniformly induced. Because.

(Embodiment 6)
Next, an example of the electromagnetic wave plasma generation method according to the embodiment of the present invention will be described using the electromagnetic wave plasma generator 101.
As described above, the electromagnetic wave plasma generator 101 is configured to apply a bias voltage to the chamber 10 provided with the gas supply unit 40, the gas discharge unit 41, and the electromagnetic wave supply unit 22, and the pipe-shaped target member 18. Means 30 are provided. The electromagnetic wave supply unit 22 includes a dielectric 35 and a coaxial cable 60 connected to the electromagnetic wave supply source 20, and the dielectric 51 is disposed at a desired position in the chamber 10. A pipe-shaped member 18 having a hollow portion 5 having at least one opening 5 a is disposed inside the chamber 10 with the opening 5 a facing the electromagnetic wave supply portion 22.
After reducing the pressure inside the chamber 10 and flowing Ar gas from the gas supply unit 40 at a flow rate of 40 sccm, the valve of the gas discharge unit 41 is adjusted to keep the amount of gas in the chamber 10 constant, The initial plasma is formed in the proximity region of the electromagnetic wave supply unit 22 with a constant value. Thereafter, an electromagnetic wave having a frequency of 100 MHz to 100 GHz is radiated from the electromagnetic wave supply unit 22, and then a negative bias voltage is gradually applied to the pipe-shaped member 18. The linear conductor 7 which is the plasma induction means 1 induces the plasma generation region generated in the chamber 10 into the hollow portion 5, and when the negative bias voltage is reached, the entire plasma is ignited. By igniting the entire surface of the plasma, the inside of the pipe-shaped member 18 can be uniformly subjected to plasma surface treatment.

  Further, by providing the insulating thin film 12 on the outer surface 18c of the pipe-shaped member 18 as the plasma guiding means 1, electromagnetic wave plasma can be induced inside the pipe-shaped member 18 and the pipe-shaped member The inside of the processing member 18 can be uniformly plasma processed.

(Embodiment 7)
Next, an example of the electromagnetic wave plasma surface treatment apparatus according to the embodiment of the present invention will be described using the electromagnetic wave plasma generator 101.
As shown in FIG. 1, an electromagnetic wave plasma surface treatment apparatus according to an embodiment of the present invention includes a gas supply unit 40 provided with a reaction gas supply means 42 for nitriding, cleaning, or plasma CVD surface treatment. Yes.
Therefore, a predetermined reaction gas for surface treatment can be introduced into the chamber 10 from the supply means 42 via the gas supply unit 40, and the inner wall surface 18c of the pipe-shaped member 18 is subjected to the predetermined reaction for surface treatment. Plasma surface treatment can be performed with gas.

(Embodiment 8)
Next, an example of the electromagnetic wave plasma surface treatment method according to the embodiment of the present invention will be described using the electromagnetic wave plasma generator 101.
As described in the sixth embodiment, the surface treatment reaction gas is introduced from the supply means 42 into the chamber 10 through the gas supply unit 40 in a state where the electromagnetic wave plasma is entirely ignited inside the pipe-shaped member 18. The inner wall surface 18c of the pipe-shaped member 18 is subjected to plasma surface treatment with this surface treatment reaction gas. For example, when a surface treatment reaction gas for plasma CVD is used, a thin film having a uniform thickness can be formed on the inner wall surface 18c of the member 18 to be processed by the plasma CVD method.
Hereinafter, effects of the embodiment of the present invention will be described.

  In the electromagnetic wave plasma generating apparatus 101 according to the embodiment of the present invention, the plasma guiding means 1 has the longitudinal direction parallel to the longitudinal direction of the pipe-shaped member 18 and is not in contact with the inner wall surface 5c of the hollow portion 5. Are disposed inside the hollow portion 5 and arranged so as to have a coaxial structure inside the hollow portion 5 of the pipe-shaped member 18. Electromagnetic wave plasma can be formed around the body 7 along the internal shape of the hollow portion 5.

  In the electromagnetic wave plasma generator 101 according to the embodiment of the present invention, the other end side 7b of the linear conductor 7 is connected to the electromagnetic wave supply unit from the other opening 5b of the hollow portion 5 of the pipe-shaped member 18 to the outside. Since the antenna portion 2 is arranged so as to protrude by a length that is an integral multiple of 1/4 of the wavelength of the electromagnetic wave radiated from 22, when the electromagnetic wave reaches another opening 5 b of the hollow portion 5. , No reflection can occur. As a result, the electromagnetic wave can be prevented from forming a standing wave along the axial direction of the hollow portion 5, and the electromagnetic wave plasma can be generated uniformly.

  In the electromagnetic wave plasma generating apparatus 102 according to the embodiment of the present invention, the electromagnetic wave absorbing member 70 is disposed on the other opening 5b side of the hollow portion 5 of the pipe-shaped member 18, so that another opening of the hollow portion 5 is provided. When electromagnetic waves reach the part 5b, reflection can be prevented. As a result, the electromagnetic wave can be prevented from forming a standing wave along the axial direction of the hollow portion 5, and the electromagnetic wave plasma can be generated uniformly.

  In the electromagnetic wave plasma generator 103 according to the embodiment of the present invention, the insulating thin film 12 is provided on the outer surface 18c of the pipe-shaped member 18 so that the electromagnetic wave reaches the other opening 5b of the hollow portion 5. In this case, reflection can be prevented. As a result, the electromagnetic wave can be prevented from forming a standing wave along the axial direction of the hollow portion 5, and the electromagnetic wave plasma can be generated uniformly.

  In the electromagnetic wave plasma generators 101 to 105 according to the embodiment of the present invention, the pipe-shaped member 18 is connected to the bias applying means 30 provided outside the chamber 10 via the wiring 32. A negative bias voltage can be applied to the pipe-shaped member 18 and the electromagnetic wave plasma can be expanded.

  In the electromagnetic wave plasma generators 101 to 105 according to the embodiment of the present invention, since the electromagnetic wave supply unit 22 includes the dielectric 51, the electromagnetic wave is transmitted through the dielectric 51 to the target member 3 in the chamber 10. It can be easily introduced inside.

  In the electromagnetic wave plasma generator 105 according to the embodiment of the present invention, a flange portion 50 having a coaxial inner conductor portion 59 penetrating a dielectric 51 is disposed in the electromagnetic wave supply portion 22, and an electromagnetic wave is provided outside the chamber of the flange portion 50. Since the plasma guiding means 1 is connected to the inside of the chamber of the flange portion 50, the electromagnetic wave generated by the electromagnetic wave supply source 20 is transmitted through the dielectric 51 to the flange portion. The electromagnetic wave can be propagated in the chamber 10 by being guided by the 50 coaxial inner conductor portions 59, and accordingly, electromagnetic wave plasma can be generated.

  Since the method for generating electromagnetic wave plasma according to the embodiment of the present invention allows the antenna unit 2 to function as a surface wave antenna, the electromagnetic wave is reflected when the electromagnetic wave reaches another opening 5b of the hollow portion 5. It is possible to prevent the electromagnetic wave from forming a standing wave along the axial direction of the hollow portion 5, and to generate the electromagnetic wave plasma more uniformly.

  In the method of generating electromagnetic wave plasma according to the embodiment of the present invention, the electromagnetic wave reaches the opening 5b by disposing the electromagnetic wave absorbing member 70 in another opening 5b of the hollow part 5 of the pipe-shaped member 18. At this time, reflection of electromagnetic waves can be prevented, electromagnetic waves can be prevented from forming standing waves in the member to be treated 3, and electromagnetic wave plasma can be generated more uniformly.

  In the method for generating electromagnetic wave plasma according to the embodiment of the present invention, when the negative bias voltage is direct current, the insulating thin film 12 is provided on the outer surface 18c of the pipe-shaped member 18 so that the plasma phase is changed to the pipe-shaped member. 18 can be confined inside and plasma can be induced.

  Since the method for generating electromagnetic wave plasma according to the embodiment of the present invention is configured to apply a negative bias voltage to the pipe-shaped member 18, plasma generated along the electromagnetic wave can be strengthened.

  Since the electromagnetic wave plasma generation method according to the embodiment of the present invention is configured such that electromagnetic waves are emitted from the electromagnetic wave supply unit 22 toward the pipe-shaped member 18 via the dielectric 51, it is easy and efficient. In addition, electromagnetic wave plasma can be generated inside the pipe-shaped member 18.

  Since the method for generating electromagnetic wave plasma according to the embodiment of the present invention generates plasma by electromagnetic waves, the plasma surface treatment can be performed at low cost with high energy efficiency compared to a magnetron method or the like.

  The electromagnetic wave plasma generation method according to the embodiment of the present invention can be applied to individual sub-hollows even in the case of the valve-shaped member 19 in which two sub-hollow parts 16 and 17 are present in another opening 5 b of the hollow part 5. By arranging the plasma guiding means 1 in the parts 16 and 17, the electromagnetic wave can be guided from the opening 5a of the hollow part 5 to the sub-hollow parts 16 and 17 provided in the other opening part 5b. In addition, the inner surfaces of the sub-hollow portions 16 and 17 can be plasma treated uniformly.

  Since the plasma surface treatment apparatus according to the embodiment of the present invention is configured to attach the surface treatment gas supply unit 42 to the electromagnetic wave plasma generators 101 to 105, the surface treatment gas can be easily supplied. Even in the case of the pipe member to be processed 18 having a high aspect shape or the valve member to be processed 19 having a complicated piping shape, it is possible to easily and uniformly plasma-treat the inner surface thereof.

The plasma surface treatment method according to an embodiment of the present invention is a method of forming a film by supplying a reactive gas for surface treatment using the electromagnetic wave plasma generation method described above. Even in the member 18 or in the valve-shaped member 19 having a complicated piping shape, electromagnetic wave plasma can be generated easily and uniformly, and the inner surface can be plasma-treated.
Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited only to these examples.

Example 1
An experiment was conducted to confirm whether plasma could be uniformly formed in the pipe along the internal shape, using the processing target member made of SUS having the valve shape shown in FIG.
No coating treatment is performed on the outer surface of the member to be processed. This member to be processed is placed in the chamber, and as shown in FIG. 4, the opened hollow portion is placed on the dielectric that is the electromagnetic wave supply portion, and the tungsten wire that is the plasma induction means is placed in the sub hollow portion. (W line) was inserted so as not to contact the inner wall, and was fixed to a grounding member arranged at a position 3 cm from the other end side of the sub hollow portion.
After reducing the pressure in the chamber and allowing Ar gas to flow in from the gas supply unit at a flow rate of 40 sccm, the valve in the gas discharge unit is adjusted so that the amount of gas in the chamber is constant and the pressure in the chamber is 93 Pa. Plasma was formed in the vicinity of the supply port. Thereafter, an electromagnetic wave having a frequency of 2.5 GHz and a wavelength of 12 cm (in vacuum) was radiated from the electromagnetic wave supply unit, and then the bias voltage applied to the member to be processed was changed from 0V to −100V.
When a bias voltage of −66 V was applied, the entire plasma was ignited, and light emission from the fine observation hole provided on the side surface of the pipe could be confirmed.

(Example 2)
An experiment was conducted to confirm whether plasma could be uniformly formed in the pipe along the internal shape, using the processing target member made of SUS having the valve shape shown in FIG.
A silica coating treatment was performed on the outer surface of the member to be treated. This member to be treated was placed in the chamber, and as shown in FIG. 4, the opened hollow part was placed on a dielectric that was an electromagnetic wave supply part. However, unlike Example 1, no tungsten wire (W line) as a plasma guiding means was disposed in the sub-hollow portion.
After reducing the pressure in the chamber and allowing Ar gas to flow in from the gas supply unit at a flow rate of 40 sccm, the valve in the gas discharge unit is adjusted so that the amount of gas in the chamber is constant and the pressure in the chamber is 93 Pa. Plasma was formed in the vicinity of the supply port. Thereafter, an electromagnetic wave having a frequency of 2.5 GHz and a wavelength of 12 cm (in vacuum) was radiated from the electromagnetic wave supply unit, and then the bias voltage applied to the member to be processed was changed from 0V to −100V.
When a bias voltage of −83 V was applied, the entire plasma was ignited, and light emission from the fine observation hole provided on the side surface of the pipe could be confirmed.

(Comparative Example 1)
An experiment was conducted to confirm whether plasma could be uniformly formed in the pipe along the internal shape, using the processing target member made of SUS having the valve shape shown in FIG.
No coating treatment is performed on the outer surface of the member to be processed. This member to be treated was placed in the chamber, and as shown in FIG. 4, the opened hollow part was placed on a dielectric that was an electromagnetic wave supply part. However, unlike Example 1, no tungsten wire (W line) as a plasma guiding means was disposed in the sub-hollow portion.
After reducing the pressure in the chamber and allowing Ar gas to flow in from the gas supply unit at a flow rate of 40 sccm, the valve in the gas discharge unit is adjusted so that the amount of gas in the chamber is constant and the pressure in the chamber is 93 Pa. Plasma was formed in the vicinity of the supply port. Thereafter, an electromagnetic wave having a frequency of 2.5 GHz and a wavelength of 12 cm (in vacuum) was radiated from the electromagnetic wave supply unit, and then the bias voltage applied to the member to be processed was changed from 0V to −100V.
Even when the bias voltage was set to −100 V, the plasma was not ignited on the entire surface, and light emission from the fine observation hole provided on the side surface of the pipe could not be confirmed.
Table 1 shows the experimental conditions and experimental results of Examples 1 and 2 and Comparative Example 1.

(Example 3)
Whether or not plasma can be uniformly formed in the pipe along the internal shape using a SUS treated pipe (1/4 inch pipe) with a 1/4 inch diameter and 100 mm long pipe shape An experiment to confirm was conducted.
A silica coating treatment was performed on the outer surface of the member to be treated. This member to be processed is placed in the chamber, and as shown in FIG. 3, the opening of the opened hollow portion is placed on the dielectric that is the electromagnetic wave supply unit, and another opening of the opened hollow portion is placed. Inserted a tungsten wire (W wire) as plasma guiding means so as not to contact the inner wall. Moreover, this W line | wire was arrange | positioned so that it might protrude outside about 3 cm from another opening part of the opened hollow part.
After reducing the pressure in the chamber and allowing Ar gas to flow in from the gas supply unit at a flow rate of 40 sccm, the valve in the gas discharge unit is adjusted so that the amount of gas in the chamber is constant and the pressure in the chamber is 93 Pa. Plasma was formed in the vicinity of the supply port. Thereafter, an electromagnetic wave having a frequency of 2.5 GHz and a wavelength of 12 cm (in vacuum) was radiated from the electromagnetic wave supply unit, and then the bias voltage applied to the member to be processed was changed from 0V to −50V.
When a bias voltage of −46 V was applied, the entire plasma was ignited, and light emission from a fine observation hole provided on the side surface of the pipe could be confirmed.

(Comparative Example 2)
An experiment was conducted to confirm whether plasma could be uniformly formed in the pipe along the internal shape using a member to be processed made of SUS having a pipe-like shape having a 1/4 inch diameter and a length of 100 mm.
No coating treatment was performed on the outer surface of the member to be treated. Further, as in Example 3, the member to be processed was placed in the chamber, and the opened hollow part was placed on the dielectric serving as the electromagnetic wave supply part. The wire (W line) was not arranged.
After reducing the pressure in the chamber and allowing Ar gas to flow in from the gas supply unit at a flow rate of 40 sccm, the valve in the gas discharge unit is adjusted so that the amount of gas in the chamber is constant and the pressure in the chamber is 93 Pa. Plasma was formed in the vicinity of the supply port. Thereafter, an electromagnetic wave having a frequency of 2.5 GHz and a wavelength of 12 cm (in vacuum) was radiated from the electromagnetic wave supply unit, and then the bias voltage applied to the member to be processed was changed from 0V to −50V.
Even when the bias voltage was set to −50 V, the plasma was not ignited on the entire surface, and light emission from the fine observation hole provided on the side surface of the pipe could not be confirmed.
The experimental conditions and experimental results of Example 3 and Comparative Example 2 are shown in Table 2 above.

Example 4
Using an object to be processed made of SUS having a pipe shape with a 1/4 inch diameter and a length of 100 mm, the power of electromagnetic waves necessary to uniformly form plasma in the pipe along the internal shape An experiment was conducted to confirm how much difference there was between the case where the portion 2 was formed and the case where the portion 2 was not formed.
A silica coating treatment was performed on the outer surface of the member to be treated. This member to be processed is placed in the chamber, and as shown in FIG. 3, the opening of the opened hollow portion is placed on the dielectric that is the electromagnetic wave supply unit, and another opening of the opened hollow portion is placed. Inserted a tungsten wire (W wire) as plasma guiding means so as not to contact the inner wall. Moreover, this W line | wire was arrange | positioned so that it might protrude outside about 3 cm from another opening part of the opened hollow part.
After reducing the pressure in the chamber and allowing Ar gas to flow from the gas supply unit at a flow rate of 20 sccm, the valve of the gas discharge unit is adjusted so that the amount of gas in the chamber is constant and the pressure in the chamber is 32 Pa. Plasma was formed in the vicinity of the supply port. Thereafter, an electromagnetic wave with a frequency of 2.5 GHz and a wavelength of 12 cm (in a vacuum) was radiated from the electromagnetic wave supply unit with a power of 100 W, and then the bias voltage applied to the member to be processed was changed from 0V to −54V. Thereafter, the power of the electromagnetic wave was changed from 100 W to 300 W.
When the electromagnetic wave power was 300 W, the plasma was completely ignited, and light emission from the fine observation hole provided on the side surface of the pipe could be confirmed.

(Example 5)
Silica coating treatment was performed on the outer surface of the member to be treated made of SUS having a pipe-like shape with a 1/4 inch diameter and a length of 100 mm. Further, as in Example 4, this member to be processed was placed in the chamber, and the opened hollow part was placed on the dielectric that was the electromagnetic wave supply part. The wire (W line) was not arranged.
After reducing the pressure in the chamber and allowing Ar gas to flow from the gas supply unit at a flow rate of 20 sccm, the valve of the gas discharge unit is adjusted so that the amount of gas in the chamber is constant and the pressure in the chamber is 32 Pa. Plasma was formed in the vicinity of the supply port. Thereafter, an electromagnetic wave with a frequency of 2.5 GHz and a wavelength of 12 cm (in a vacuum) was radiated from the electromagnetic wave supply unit with a power of 100 W, and then the bias voltage applied to the member to be processed was changed from 0V to −54V. Thereafter, the power of the electromagnetic wave was changed from 100 W to 300 W.
Even when the power of the electromagnetic wave was set to 300 W, the plasma was not ignited on the entire surface, and light emission from the fine observation hole provided on the side surface of the pipe could not be confirmed.
Further, when the electromagnetic wave power was increased to 500 W, the plasma was completely ignited, and light emission from the fine observation hole provided on the side surface of the pipe could be confirmed.
Table 3 shows the experimental conditions and experimental results of Example 4 and Example 5.

  The present invention relates to an electromagnetic wave plasma generator and a generation method thereof. By using the generator and the generation method, the surface of the pipe-shaped pipe having a high aspect ratio can be cleaned with a gas. It can be coated with a corrosion-resistant thin film. Therefore, it can be used in the semiconductor industry using corrosive gas.

It is a cross-sectional schematic diagram which shows an example of the electromagnetic wave plasma generator which is embodiment of this invention. It is a cross-sectional schematic diagram which shows an example of the electromagnetic wave plasma generator which is embodiment of this invention. It is a cross-sectional schematic diagram which shows an example of the electromagnetic wave plasma generator which is embodiment of this invention. It is a cross-sectional schematic diagram which shows an example of the electromagnetic wave plasma generator which is embodiment of this invention. It is a cross-sectional schematic diagram which shows an example of the electromagnetic wave plasma generator which is embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plasma guidance means 1a ... One end side, 1b ... Other end side, 2 ... Antenna part, 3 ... Member to be processed, 3a ... One end side, 3b ... Other end side, 5 ... Hollow part, 5a ... Opening part, 5b ... another opening, 7 ... linear conductor, 7a ... one end side, 7b ... other end side, 10 ... chamber, 11 ... hole, 12 ... insulating thin film, 14 ... grounding part, 15 ... branching part, DESCRIPTION OF SYMBOLS 16, 17 ... Sub hollow part, 18 ... Pipe-shaped to-be-processed member, 19 ... Valve-shaped to-be-processed member, 20 ... Electromagnetic wave supply source, 22 ... Electromagnetic wave supply part, 30 ... Bias application means, 32 ... Wiring, 40 ... Gas supply , 41 ... Gas discharge part, 42 ... Reaction gas supply part, 50 ... Flange part, 51 ... Dielectric, 53 ... Connector part, 55 ... Seal part, 56 ... Insulating ring part, 57 ... External antenna part, 59 ... Coaxial Inner conductor part, 60 ... coaxial cable, 62 ... inner conductor part, 63 ... outer conductor , 64 ... support portion, 70 ... electromagnetic wave absorbing member, 101, 102 ... electromagnetic wave plasma generator.

Claims (14)

A chamber having a gas supply unit, a gas discharge unit, and an electromagnetic wave supply unit, and bias applying means for applying a bias voltage to a member to be processed, and having a hollow portion having at least one opening An electromagnetic wave plasma generator for generating plasma inside a hollow part of a member,
The electromagnetic wave supply unit is disposed at a desired position in the chamber, and the member to be processed is disposed in the chamber.
An electromagnetic wave plasma generator comprising at least one plasma guiding means for guiding a plasma generation region generated in the chamber into the hollow portion.   The electromagnetic wave plasma generator according to claim 1, wherein the electromagnetic wave supply unit is disposed at a position where the opening of the member to be processed is desired.   3. The electromagnetic wave plasma generator according to claim 1, wherein the plasma guiding means is a linear conductor disposed in the hollow portion of the member to be processed.   The electromagnetic wave plasma generator according to any one of claims 1 to 3, wherein the plasma guiding means is an insulating thin film applied to an outer surface of the member to be processed.   5. The electromagnetic wave plasma generator according to claim 4, wherein the insulating thin film is a silica coat.   The electromagnetic wave plasma generator according to any one of claims 1 to 5, wherein the linear conductor is disposed coaxially with a central axis of the hollow portion. In the case where another opening is provided in the hollow portion,
One end side of the linear conductor is disposed inside the hollow portion,
The other end of the linear conductor is arranged to protrude from the other opening, and the protruding length is an integral multiple of 1/4 of the wavelength of the electromagnetic wave propagating from the inside of the member to be processed to the outside. The electromagnetic wave plasma generator according to any one of claims 1 to 6, characterized in that In the case where another opening is provided in the hollow portion,
The electromagnetic wave plasma generating apparatus according to claim 1, wherein an electromagnetic wave absorbing member is disposed in the another opening.   The electromagnetic wave supply unit includes a dielectric disposed at a desired position in the chamber, and a coaxial cable or a waveguide connected to the dielectric for supplying electromagnetic waves into the chamber via the dielectric. The electromagnetic wave plasma generator according to any one of claims 1 to 8, characterized by comprising:   The electromagnetic wave plasma generator according to claim 9, wherein the linear conductor is connected to the dielectric. The dielectric is provided inside a flange portion disposed at a desired position in the chamber;
The flange portion is provided with a coaxial inner conductor portion that penetrates the dielectric and forms a coaxial line with the flange portion,
The linear conductor is connected to one end side of the coaxial inner conductor portion,
11. The electromagnetic wave plasma generating apparatus according to claim 9, wherein a coaxial cable or a waveguide is connected to the other end side of the coaxial inner conductor portion. Using a chamber provided with a gas supply unit, a gas discharge unit and an electromagnetic wave supply unit, and a bias application means for applying a bias voltage to the member to be processed,
An electromagnetic wave plasma generating method for generating electromagnetic wave plasma inside a hollow portion of a member to be processed having a hollow portion having at least one opening,
The electromagnetic wave supply unit is disposed at a desired position in the chamber, and the member to be processed is disposed in the chamber.
A method for generating electromagnetic wave plasma, wherein a plasma generation region generated in the chamber is guided into the hollow portion by a plasma guiding means.   11. The electromagnetic wave plasma surface treatment characterized in that the electromagnetic wave plasma generator according to claim 1 is provided with means for supplying a reactive gas for nitriding, cleaning or plasma CVD surface treatment. apparatus. The method for generating electromagnetic plasma according to claim 12,
An electromagnetic wave plasma surface treatment method comprising: generating electromagnetic wave plasma to surface-treat the inner wall surface of a member to be treated while supplying a reaction gas for nitriding, cleaning or plasma CVD surface treatment into the chamber.

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