JP2010103455A - Plasma processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a plasma processing apparatus capable of uniformly performing plasma processing such as deposition for a semiconductor or a workpiece having a low resistance value such as conductivity, even in a condition that a gas pressure of a reaction gas is high. <P>SOLUTION: The plasma processing apparatus includes: a plasma generator for generating plasma in a gap between a first electrode 12 and a grounded second electrode 10; a power supply 14 for applying power to the first electrode; and a gas supply source 16 for supplying a reaction gas to the gap between the first electrode and the second electrode. The plasma processing apparatus irradiates the member to be treated which is arranged so that a plasma flow jetting direction from the plasma generator may be substantially perpendicular to the surface to be treated, with the plasma flow obtained by making the reaction gas plasma by circulating the reaction gas in the gap between the first electrode and the second electrode while the power is applied to the first electrode by the power supply. In the plasma processing apparatus, the minimum gap dimension of the gap between the first electrode and the surface to be treated is larger than the minimum gap dimension of the gap between the first electrode and the second electrode in the vicinity of a jetting portion for jetting the plasma flow in the plasma generator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus.

Conventionally, techniques using plasma include a technique for forming a film on the surface of a member to be processed, and a technique for processing the surface of the member to be processed. As a plasma processing apparatus using plasma, for example, there is a plasma processing apparatus that forms a thin film under a relatively high pressure of 10 Torr or more. As such a technique, in order to form a uniform plasma under a high pressure in the vicinity of atmospheric pressure, a sample substrate grounded to ground is arranged between two electrodes facing each other, and a reactive gas is provided with a porous electrode. There is disclosed a technique in which film formation is performed by spraying toward a sample substrate and applying high-frequency power between two electrodes to excite plasma between the electrode and the sample substrate (see, for example, Patent Document 1). And in this patent document 1, the technique of obtaining a silicon film on the sample substrate which has a resistivity of 10 ¹¹ Ω · cm or more as the sample substrate is disclosed.

Japanese Patent Laid-Open No. 2-73797

  However, according to the above conventional technique, when there is a low resistance film or base material such as a semiconductor or a conductive film in a state where the reaction gas pressure is high, a porous substrate functioning as a high frequency electrode and a substrate grounded to the ground There is a problem that the electric field distribution is easily disturbed, and when this electric field distribution is disturbed, plasma is generated non-uniformly and uniform film formation cannot be performed.

  The present invention has been made in view of the above, and plasma processing such as film formation is uniformly applied to a member to be processed having a low resistance value, such as a semiconductor or conductivity, even under a high gas pressure of a reaction gas. It is an object of the present invention to obtain a plasma processing apparatus that can be used.

  In order to solve the above-described problems and achieve the object, a plasma processing apparatus according to the present invention includes a plasma generator for generating plasma in a gap between a first electrode and a grounded second electrode, and the first electrode. A power source that applies power to the first electrode, and a gas supply source that supplies a reactive gas to a gap between the first electrode and the second electrode, and the first electrode is configured to apply power to the first electrode by the power source. A plasma flow in which the reaction gas is converted into plasma by circulating the reaction gas through the gap between the first electrode and the second electrode in a state where an electric field is generated in the gap between the second electrode and the second electrode. A plasma processing apparatus for irradiating a member to be processed disposed such that a jet direction of a plasma flow from the plasma generator is substantially perpendicular to a surface to be processed, the gap between the first electrode and the surface to be processed The minimum gap dimension is It in serial plasma generator is greater than the minimum gap dimension of the gap between the first electrode and the second electrode of the jet vicinity for ejecting said plasma flow, characterized by.

  According to this invention, even if the member to be processed is made of a material having a low resistivity such as a semiconductor or a conductive substrate, the member to be processed can be uniformly irradiated with a plasma flow. There is an effect that the plasma treatment can be uniformly applied to the member.

FIG. 1 is a schematic diagram showing a basic configuration of a plasma processing apparatus according to a first embodiment of the present invention. FIG. 2-1 is a schematic diagram for explaining a state of a plasma flow blown out from a gas outlet when VS> VG in the plasma processing apparatus. FIG. 2B is a schematic diagram for explaining the state of the plasma flow blown out from the gas outlet when VS ≦ VG in the plasma processing apparatus. FIG. 3 is a schematic diagram illustrating another configuration example of the plasma processing apparatus according to the first exemplary embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a configuration example of another plasma processing apparatus according to the first embodiment of the present invention. FIG. 5-1 is a cross-sectional view of a principal part showing a schematic configuration of the plasma processing apparatus according to the second embodiment of the present invention. FIG. 5-2 is a plan view of the plasma generator of the plasma processing apparatus according to the second exemplary embodiment of the present invention viewed from the direction of arrow A in FIG. FIG. 5-3 is a plan view of the plasma generator of the plasma processing apparatus according to the second exemplary embodiment of the present invention, viewed from the direction of arrow B in FIG. 5-1. FIG. 6 is a cross-sectional view of a main part showing a schematic configuration of the plasma processing apparatus according to the third embodiment of the present invention. FIG. 7 is a schematic diagram showing a schematic configuration of the plasma processing apparatus according to the fourth embodiment of the present invention. FIG. 8 is a schematic diagram showing the configuration of the plasma processing apparatus according to the fifth embodiment of the present invention. FIG. 9 is a schematic diagram showing the configuration of the plasma processing apparatus according to the sixth embodiment of the present invention. FIG. 10 is a schematic diagram showing the configuration of the plasma processing apparatus according to the seventh embodiment of the present invention.

  Embodiments of a plasma processing apparatus according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings. In the following drawings, the same or similar parts are denoted by the same or similar reference numerals.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing a basic configuration of a plasma processing apparatus according to a first embodiment of the present invention. As shown in FIG. 1, the plasma processing apparatus includes a cylindrical ground electrode 10 (corresponding to the second electrode in the claims) having a hollow central portion in the diameter direction, and a substantially central portion in the hollow portion of the ground electrode 10. A cylindrical voltage electrode 12 (corresponding to the first electrode in the claims) disposed opposite to the ground electrode 10, a power supply 14 for applying power to the voltage electrode 12, and a gap between the ground electrode 10 and the voltage electrode 12. A substrate that is grounded and holds the substrate 20 so that the surface to be processed of the substrate 20 that is a member to be processed is substantially perpendicular to the axial direction of the voltage electrode 12 and the ground electrode 10. A stand 18 is provided.

    Here, the ground electrode 10, the voltage electrode 12, and the power source 14 constitute a plasma generator that generates plasma. The gap between the ground electrode 10 and the voltage electrode 12 is a flow path for the reaction gas supplied from the gas supply unit 16, and the gas supply unit 16 side of the gap between the ground electrode 10 and the voltage electrode 12 introduces gas. It becomes the opening 22, and the substrate 20 side becomes the gas outlet 24.

  In the plasma processing apparatus according to the present embodiment, the voltage electrode 12 and the ground electrode are applied in a state where electric power is applied to the voltage electrode 12 by the power source 14 to generate a discharge in the gap between the voltage electrode 12 and the ground electrode 10. The plasma flow, which is a gas flow including plasma generated by exciting the reaction gas into the gap between the plasma generator 10 and the plasma gas, is ejected from the plasma generator so that the direction of jetting of the plasma flow is substantially perpendicular to the surface to be processed. It irradiates the board | substrate 20 arrange | positioned so that it may become.

  The inner peripheral surface of the ground electrode 10 has different inner diameters in the central axis direction of the ground electrode 10. The inner peripheral surface of the ground electrode 10 has an inclined portion near the central portion in the central axis direction, and the inner diameter of the region of the gas inlet 22 (gas inflow side) in the central axis direction is the gas outlet 24 (gas The inner diameter of the region on the outflow side). As a result, the gap between the ground electrode 10 and the voltage electrode 12 is narrower in the region downstream of the gas flow channel than in the region upstream of the gas flow channel. Pressure increases. Of the gap between the ground electrode 10 and the voltage electrode 12, the region on the gas outflow side in the central axis direction of the ground electrode 10 (the region where the gap between the ground electrode 10 and the voltage electrode 12 is narrow) Become.

The ground electrode 10 has an inner peripheral surface facing the voltage electrode 12 covered with an insulating film 28 along the inner peripheral surface. The role of the insulating film 28 is to prevent arcing between the ground electrode 10 and the voltage electrode 12. When an arc is generated between the ground electrode 10 and the voltage electrode 12, the electrode may be dissolved and impurities may be mixed into the plasma flow. As such an insulating film 28, for example, a silicon oxide (SiO ₂ ) film or an aluminum oxide (Al ₂ O ₃ ) film is suitable. It should be noted that this insulating film is always necessary when a discharge gas is generated between the ground electrode 10 and the voltage electrode 12 with a high-frequency current such as 13.56 MHz using a reaction gas that hardly generates an arc, for example, helium (He) gas. Absent. Here, an example is shown in which the surface of the ground electrode 10 facing the voltage electrode 12 is covered with an insulating film 28, but at least one of the ground electrode 10 and the voltage electrode 12 is insulated on the surface facing the other electrode. It suffices if the film is coated, and both electrodes may be coated with an insulating film.

  Then, grounding is performed so that the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is larger than the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12 (VS> VG). Electrode 10 and voltage electrode 12 are arranged. The electric field distribution varies depending on the resistivity of the neighboring objects. For this reason, when there is a material having high conductivity (low resistance) in the vicinity of the voltage electrode 12 and the ground electrode 10 in a state where the reaction gas pressure is relatively high, for example, the substrate 20 has a low resistance such as a semiconductor or a conductive film. When made of materials or when a film of these materials is formed, the electric field distribution between the voltage electrode 12 and the ground electrode 10 tends to be disturbed.

  If the electric field distribution is disturbed, plasma is generated non-uniformly and a uniform plasma treatment cannot be performed. When the substrate 20 is made of a low-resistance material such as a semiconductor or a conductive film, or when a film of these materials is formed, an electric field between the voltage electrode 12 and the ground electrode 10 in the vicinity of the gas ejection port 24. Is bent toward the substrate side, and the plasma flow is concentrated and blown out in the region immediately below the voltage electrode 12 due to this influence. In this case, uniform film formation cannot be performed.

  However, by increasing VS as compared with VG, the substrate 20 is a semiconductor substrate or a conductive substrate, or even when a film of these materials is formed on the substrate 20 or the like. The influence of the electric field disturbance can be prevented, the plasma flow can be uniformly irradiated from the gas ejection port 24 to the substrate, and uniform film formation and processing can be performed.

  FIG. 2A is a schematic diagram for explaining a state of the plasma flow 30 blown out from the gas outlet 24 when VS> VG. FIG. 2B is a schematic diagram for explaining the state of the plasma flow 30 blown out from the gas outlet 24 when VS ≦ VG. Plasma is generated in a narrow gap (a downstream area of the gas flow path) of the gap between the ground electrode 10 and the voltage electrode 12, and the plasma flow is caused by the flow of the reaction gas introduced from the gas inlet 22. 30 is irradiated onto the substrate 20.

For example, when a semiconductor substrate having a resistivity of 10 ⁴ Ω · cm or less is used as the substrate 20, when VS is VG or less, the plasma flow 30 is concentrated in a region immediately below the voltage electrode 12 as shown in FIG. And blown out. On the other hand, when VS is made larger than VG, as shown in FIG. 2A, the plasma flow 30 is uniformly irradiated in a shape reflecting a tapered nozzle shape formed on the inner surface of the ground electrode 10. Therefore, uniform film formation and processing can be performed on the substrate 20. FIGS. 2-1 and 2-2 show the case where the inner surface of the ground electrode 10 has a tapered nozzle shape on the downstream side of the gas flow path, but the straight nozzle shape as shown in FIG. The same applies to the case of having.

  Further, the ground electrode 10 is disposed so as to protrude in the direction of the substrate 20 (surface to be processed) with respect to the voltage electrode 12 in the central axis direction, and the inner peripheral surface (insulating film) of the protruding portion of the ground electrode 10 28) serves as a guide when the plasma flow generated by the plasma generator 26 is blown out.

  The gas pressure at the gas outlet 24 when the gas supply unit 16 supplies the reaction gas to the gap between the ground electrode 10 and the voltage electrode 12 is, for example, in the range of 20 Torr to 760 Torr. When the gas pressure at the gas outlet 24 is within this pressure range, the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12 is about 0.5 mm to 3 mm, and between the ground electrode 10 and the voltage electrode 12. Discharge occurs stably. On the other hand, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is preferably a distance of about 4 mm to 10 mm.

  In the plasma generation unit 26, the film is formed on the substrate 20 on at least one of the surface of the ground electrode 10 facing the voltage electrode 12 and the surface of the voltage electrode 12 facing the ground electrode 10. It is preferable that a material having substantially the same composition as the coating is coated. Thereby, it is possible to minimize the mixing of impurities into the film formed on the substrate 20. This is very effective when a high-purity thin film is obtained on the surface of the substrate 20. In addition, the material coated on the facing surface as described above can be decomposed by plasma and deposited on the substrate 20, and the use of a highly toxic material gas or the like can be reduced.

  In FIG. 1, the substrate table 18 that holds the substrate 20 is grounded. However, as shown in FIG. 3, a DC voltage is applied to the substrate table 18 by the DC voltage source 32 and an AC voltage is generated from the AC voltage source 34. It is also possible to control the flow of the plasma flow blown out from the gas outlet 24 by the application of.

A processing example in the plasma processing apparatus having such a configuration will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating a configuration of another plasma processing apparatus according to the first embodiment. In the plasma processing apparatus of FIG. 4, a substrate table 18 containing a part of a plasma generator and a heater H is disposed in a vacuum vessel 36. On the substrate table 18, a non-alkali glass substrate having a transparent conductive film made of an indium tin oxide film formed on the surface thereof is placed as the substrate 20. The resistivity of the transparent conductive film is approximately 2.0 × 10 ⁻⁴ Ω · cm. Further, the substrate 20 is heated to, for example, about 300 ° C. by the heater H placed on the substrate table 18.

  The substrate 20 is disposed on the substrate table 18 with the surface on which the transparent conductive film is formed facing upward so that the plasma flow is blown onto the surface on which the transparent conductive film is formed. The plasma generator is disposed with the gas outlet 24 facing the substrate 20 so that a plasma flow is blown to the surface of the substrate 20 on which the transparent conductive film is formed. A vacuum pump 38 and a pressure adjustment valve 40 capable of adjusting conductance are connected to the vacuum vessel 36 via a suction pipe 42, and the pressure in the vacuum vessel 36 can be controlled. Further, the voltage electrode 12 and the ground electrode 10 are insulated by an insulator 28a.

  A high frequency power having a frequency of 13.56 MHz whose voltage waveform is a sine wave is applied to the voltage electrode 12 by the power source 14. The voltage waveform may be an impulse wave or a square wave in addition to a sine wave, or may be a voltage waveform modulated at another frequency. The frequency of the voltage may be any frequency between 10 KHz and 200 MHz. Here, 300 W of power at a frequency of 13.56 MHz is applied to the voltage electrode 12. The minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 and the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12 are VS = 5.0 mm and VG = 2.0 mm, respectively. And

The reaction gas supplied from the gas supply unit 16 to the plasma generator includes a composition ratio of 98.9 Vol% helium (He) gas, 0.1 Vol% monosilane (SiH ₄ ) gas, and 1.0 Vol% hydrogen (H ₂ ) gas. The flow rate ratio is adjusted so that the total gas pressure becomes 500 Torr. Note that the purity of each gas is preferably 99.99% or more in order to form a high-purity silicon film.

  Under the conditions as described above, when the reaction gas is supplied from the gas supply unit 16 to the plasma generator and the power is applied to the voltage electrode 12 by the power source 14, the plasma is excited in the narrow gap between the voltage electrode 12 and the ground electrode 10. The Then, the plasma flow containing the plasma is sprayed onto the substrate 20 by the flow of the reactive gas. When a plasma flow was blown on the substrate 20 for about 30 minutes by such a film forming process, a uniform silicon film having a film thickness of about 30 nm could be obtained on the surface of the substrate 20. Even when the gas pressure was relatively high, such as 500 Torr, the substrate 20 was not damaged by the arc.

  Therefore, according to the plasma processing apparatus of this embodiment, it is possible to generate a plasma flow uniformly even in a high pressure region or a substrate having a conductive film layer on the surface. It is possible to form a uniform silicon film on the substrate 20.

  As described above, in the plasma processing apparatus according to the first embodiment, the minimum gap dimension VS between the voltage electrode 12 and the surface to be processed of the substrate 20 is equal to the minimum gap between the ground electrode 10 and the voltage electrode 12. It is larger than the dimension VG (VS> VG). Thus, by increasing VS as compared with VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with a plasma flow from the gas outlet 24.

  Therefore, according to the plasma processing apparatus according to the first exemplary embodiment, even when the substrate 20 is a semiconductor substrate or a conductive substrate under a relatively high pressure of, for example, 10 Torr or more, the surface of the substrate 20 is uniform. Thin film deposition and processing are possible. And since the thin film obtained by the plasma processing apparatus concerning Embodiment 1 is a uniform and high quality thin film, it is excellent in durability.

  In the above description, the cylindrical ground electrode 10 whose center region in the diametric direction is a hollow portion, and the cylindrical ground electrode 10 disposed in a substantially central portion in the hollow portion of the ground electrode 10 so as to face the ground electrode 10. Although described in relation to the voltage electrode 12 and the substrate 20 disposed so that the surface to be processed is substantially perpendicular to the axial direction of the voltage electrode 12 and the ground electrode 10, the present invention is not limited to this and the plasma is not limited to this. It only needs to be in a form that can be generated. For example, the ground electrode 10 may be a triangular cylinder shape or a square cylinder shape, and the voltage electrode 12 may be a triangular prism shape or a quadrangular prism shape. Alternatively, the ground electrode 10 and the voltage electrode 12 may be flat and the voltage electrode 12 may be sandwiched between the two ground electrodes 10.

Embodiment 2. FIG.
FIG. 5A is a cross-sectional view of a principal part illustrating a schematic configuration of the plasma processing apparatus according to the second embodiment. In FIG. 5A, the power supply 14 and the gas supply unit 16 are omitted. FIG. 5-2 is a plan view of the plasma generator of the plasma processing apparatus according to the second embodiment when viewed from the direction of arrow A in FIG. 5-1, and FIG. 5-3 is the plasma processing according to the second embodiment. It is the top view which looked at the plasma generator of the apparatus from the direction of arrow B in FIGS.

  As shown in FIG. 5A, the plasma generator of the plasma processing apparatus according to the second exemplary embodiment basically includes a plurality of electrode structures (plasma generators) having the basic configuration described in the first exemplary embodiment arranged in an array. It has the structure made. As described above, by arranging a plurality of electrode structures (plasma generators) in the form of an array in the first embodiment, a large area is obtained even at a pressure close to atmospheric pressure under a relatively high pressure of, for example, 10 Torr or more. It is possible to spray a plasma flow onto the substrate 20 at once.

  In the plasma generator according to the second embodiment, the ground electrode 10 is attached to the voltage electrode 12 in which, for example, metallic cylindrical protrusions 12a are arranged in an array via an insulator 44, for example, an aluminum oxide spacer. The voltage electrode 12 is provided with a gas inlet 22. The ground electrode 10 is configured such that a taper-shaped nozzle having a shape along the cylindrical protrusion 12a of the voltage electrode 12 is formed in advance on a metallic disk, and the cylindrical protrusion 12a is disposed in the nozzle. As the ground electrode 10, for example, SUS, copper, brass, or silicon plate is used.

  Also in the plasma processing apparatus according to the second embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is larger than the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12. The ground electrode 10 and the voltage electrode 12 are arranged so as to be large (VS> VG). Thus, by increasing VS as compared with VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with a plasma flow from the gas outlet 24.

  The surface (metal surface) of the voltage electrode 12 facing the ground electrode 10 may be coated with an insulator such as ceramics. Thereby, generation | occurrence | production of the arc discharge between the ground electrode 10 and the voltage electrode 12 can be prevented. Further, the surface of the ground electrode 10 facing the voltage electrode 12 may be coated with an insulator such as ceramics. That is, it is only necessary that the surface of at least one of the ground electrode 10 and the voltage electrode 12 facing the other electrode is covered with the insulating film. Thereby, generation | occurrence | production of the arc discharge between the ground electrode 10 and the voltage electrode 12 can be prevented.

  As described above, also in the plasma processing apparatus according to the second embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is the minimum gap dimension of the gap between the ground electrode 10 and the voltage electrode 12. The ground electrode 10 and the voltage electrode 12 are arranged so as to be larger than VG (VS> VG). In this way, by increasing VS compared to VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is irradiated with a plasma flow uniformly from the gas ejection port 24, and uniform film formation is achieved. And processing is possible.

  Further, in the plasma processing apparatus according to the second embodiment, by arranging a plurality of plasma generators in an array, even at a pressure close to atmospheric pressure, for example, under a relatively high pressure of 10 Torr or more. It is possible to spray a plasma flow onto the large area substrate 20 in a lump, and it is possible to efficiently form a film with a large area and to perform processing.

  Therefore, according to the plasma processing apparatus according to the second embodiment, even when the substrate 20 is a semiconductor substrate or a conductive substrate under a relatively high pressure of, for example, 10 Torr or more, the surface of the substrate 20 having a large area is applied. Thus, uniform thin film formation and processing can be efficiently carried out collectively.

Embodiment 3 FIG.
In the third embodiment, a modified example of the plasma processing apparatus according to the second embodiment will be described by taking a silicon film as an example. FIG. 6 is a main part sectional view showing a schematic configuration of the plasma processing apparatus according to the third embodiment. In FIG. 6, only characteristic portions are shown, and the power source 14 and the gas supply unit 16 are omitted.

  As shown in FIG. 6, the plasma generator of the plasma processing apparatus according to the third embodiment has a configuration in which a plurality of basic electrode structures (plasma generators) are arranged in an array as in the second embodiment. Have In this way, by arranging a plurality of basic electrode structures (plasma generators) in an array, the substrate 20 having a large area can be collectively collected even at a pressure close to atmospheric pressure under a relatively high pressure of, for example, 10 Torr or more. It is possible to spray a plasma flow.

  In the plasma generator according to the third embodiment, the ground electrode 10 is attached to the voltage electrode 12 in which, for example, metallic cylindrical protrusions 12a are arranged in an array via an insulator 44. The voltage electrode 12 is provided with a gas inlet 22 and a gas flow path 48. The surface of the cylindrical protrusion 12 a, that is, the surface facing the ground electrode 10 is covered with a silicon film 46. By covering the surface of the cylindrical protrusion 12a with the silicon film 46, impurities resulting from the decomposition of the voltage electrode 12 taken into the film to be formed can be reduced. Further, the silicon film 46 can be decomposed by plasma and deposited on the substrate 20, and the use of a highly toxic reactive gas or the like for film formation can be reduced. Further, the voltage electrode 12 itself may be formed of silicon.

  Further, the plasma generator according to the third embodiment includes a cooling mechanism for the voltage electrode 12 and can cool the voltage electrode 12 via a heat radiating plate 50 provided on the top of the voltage electrode 12. Yes. For example, the heat radiating plate 50 is cooled using an external refrigerant such as a chiller, and the heat generated in the voltage electrode 12 is cooled by the heat radiating plate 50 during plasma generation by using helium gas having high thermal conductivity as a reaction gas. Can be absorbed using the reaction gas.

  When a silicon film is formed, the decomposition rate of silicon is faster as the temperature of silicon is lower. For this reason, by cooling the voltage electrode 12, the density of silicon decomposition products increases, and the film formation rate can be improved. The deposition rate and crystallinity on the substrate 20 can be controlled by heating the substrate table 18. In addition, by cooling the voltage electrode 12, it is possible to suppress the emission of electrons from the voltage electrode 12 due to heat and to make it difficult for arc discharge to occur. Although an example in which the voltage electrode 12 is cooled is shown here, the ground electrode 10 may be cooled, and in this case, the same effect can be obtained.

  The ground electrode 10 is configured such that a taper-shaped nozzle having a shape along the cylindrical protrusion 12a of the voltage electrode 12 is formed in advance on a metallic disk, and the cylindrical protrusion 12a is disposed in the nozzle. The ground electrode 10 is also covered with the silicon film 46, and the same effect as that of the voltage electrode 12 can be obtained. The ground electrode 10 itself may be formed of silicon.

  Also in the plasma processing apparatus according to the third embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is larger than the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12. The ground electrode 10 and the voltage electrode 12 are arranged so as to be large (VS> VG). Thus, by increasing VS as compared with VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with a plasma flow from the gas outlet 24.

In the plasma generating apparatus according to the third embodiment having the above configuration, a silicon film was formed. As the substrate 20, an alkali-free glass substrate on which a transparent conductive film made of an indium tin oxide film is formed is placed. The resistivity of the transparent conductive film is approximately 2.0 × 10 ⁻⁴ Ω · cm. As a reaction gas supplied from the gas supply unit 16 to the plasma generator, the flow rate ratio is adjusted so that the composition ratio of helium (He) gas 50 Vol% and hydrogen (H ₂ ) gas 50 Vol%, and the total gas pressure is 840 Torr. The flow rate was set to be This pressure may be the upstream pressure of the gas flow path. The temperature of the heat sink 50 was set to 15 ° C.

  When 300 W high frequency power of 13.56 MHz is applied to the voltage electrode 12, hydrogen radicals decomposed by the plasma decompose the silicon film of the voltage electrode 12 and the ground electrode 10, and the decomposed silicon is a substrate on which a plasma flow is blown. 20 is deposited as a silicon film. A uniform silicon film could be obtained on the substrate 20 by such plasma treatment.

  Here, in the plasma generator according to the present embodiment, since the voltage electrode 12 is cooled, the silicon decomposition rate is high, and the silicon film is formed at a higher film formation rate than when the voltage electrode 12 is not cooled. Film formation was possible. In addition, the emission of electrons from the voltage electrode 12 due to heat was suppressed by cooling the voltage electrode 12, and the occurrence of arc discharge could be prevented. Even when the gas pressure was relatively high, such as 840 Torr, the substrate 20 was not damaged by arc discharge.

  As described above, also in the plasma processing apparatus according to the third embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is the minimum gap dimension of the gap between the ground electrode 10 and the voltage electrode 12. The ground electrode 10 and the voltage electrode 12 are arranged so as to be larger than VG (VS> VG). As a result, even when the total gas pressure is as high as 840 Torr and the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with the plasma flow from the gas outlet 24 and the substrate surface is evenly distributed. Surface treatment is possible.

  Further, in the plasma processing apparatus according to the third embodiment, by arranging a plurality of plasma generators in an array, even at a pressure close to atmospheric pressure, for example, under a relatively high pressure of 10 Torr or more. It is possible to spray a plasma flow on the large-area substrate 20 at once.

  Therefore, according to the plasma processing apparatus according to the third embodiment, even when the substrate 20 is a semiconductor substrate or a conductive substrate under a relatively high pressure of, for example, 10 Torr or more, the surface of the substrate 20 having a large area is applied. Thus, a uniform thin film can be formed and processed at once.

  In addition, since the plasma processing apparatus according to the third embodiment includes a cooling mechanism for the voltage electrode 12, it is possible to improve the film formation rate when forming a silicon film or the like, and to achieve efficient formation. Film processing is possible. Further, by cooling the voltage electrode 12, it is possible to suppress the emission of electrons from the voltage electrode 12 due to heat, to suppress the occurrence of arc discharge, and to form a high-purity thin film.

  Further, in the plasma processing apparatus according to the third embodiment, since the surfaces of the ground electrode 10 and the voltage electrode 12 are covered with the silicon film 46, it is caused by the decomposition of the voltage electrode 12 taken into the film to be formed. Impurities can be reduced, and a high-purity thin film can be formed. Further, the silicon film 46 can be decomposed and deposited on the substrate 20, and the use of a highly toxic reactive gas or the like can be reduced.

Embodiment 4 FIG.
In Embodiment 4, another surface treatment method using plasma, which is different from the formation of a thin film over a substrate, will be described. FIG. 7 is a schematic diagram illustrating a schematic configuration of the plasma processing apparatus according to the fourth embodiment. The configuration of the plasma processing apparatus according to the fourth embodiment is substantially the same as the configuration shown in FIG. 4 of the first embodiment, but without using the vacuum vessel 36, the plasma generator, the substrate stage 18, and the substrate 20 are used. Is installed in the atmosphere. In addition, a pressure gauge 52 is installed near the gas inlet 22 in the ground electrode 10.

  Also in the plasma processing apparatus according to the fourth embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is larger than the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12. The ground electrode 10 and the voltage electrode 12 are arranged so as to be large (VS> VG). Thus, by increasing VS as compared with VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with a plasma flow from the gas outlet 24.

The pressure of the reaction gas supplied to the plasma generator is set to be slightly positive compared to the atmospheric pressure that is the pressure of the external atmosphere. In this way, by setting the pressure of the gas sent to the plasma generator to a positive pressure from the atmospheric pressure, the atmosphere can be prevented from being mixed into the plasma generator, and contamination from the atmosphere can be prevented. The flow rate of the reaction gas supplied to the plasma generator is set such that the pressure is 840 Torr at a composition ratio of 99.0 Vol% helium (He) gas and 1.0 Vol% hydrogen (H ₂ ) gas, for example. This pressure may be displayed on the pressure gauge 52 installed in the upstream portion of the nozzle. To the voltage electrode 12, 300 high frequency power of 13.56 MHz is applied by the power source 14.

Under the above conditions, when the reactive gas is supplied from the gas supply unit 16 to the plasma generator and the high frequency power is applied to the voltage electrode 12 by the power source 14, the plasma is excited in the narrow gap between the voltage electrode 12 and the ground electrode 10. Then, hydrogen radicals are generated by this plasma. A plasma flow containing hydrogen radicals is blown onto the substrate 20 by the flow of the reaction gas. For example, when a copper plate is used as the substrate 20, when the copper plate is irradiated with a plasma flow containing hydrogen radicals, an oxide such as copper oxide (Cu ₂ O) on the surface of the copper plate can be removed.

  As described above, also in the plasma processing apparatus according to the fourth embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is the minimum gap dimension of the gap between the ground electrode 10 and the voltage electrode 12. The ground electrode 10 and the voltage electrode 12 are arranged so as to be larger than VG (VS> VG). As a result, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly surface-treated in an atmosphere open to the atmosphere by irradiating the substrate with a plasma flow uniformly from the gas outlet 24. It is possible.

Embodiment 5 FIG.
FIG. 8 is a schematic diagram illustrating a configuration of a plasma processing apparatus according to the fifth embodiment. In the plasma processing apparatus according to the fifth embodiment, the minimum distance of the gap between the ground electrode 10 and the surface to be processed of the substrate 20 in the electrode structure (plasma generator) shown in FIG. It has a structure that is set smaller than the minimum gap dimension VS of the gap with the surface to be processed. That is, the ground electrode 10 protrudes toward the surface to be processed on the substrate 20 side with respect to the voltage electrode 12, and the protrusion dimension S of the ground electrode 10 with respect to the voltage electrode 12 is the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12. (S> VG).

  There are two advantages of having the above structure. The first advantage is that when a flexible substrate that is easily bent is used as the substrate 20, the distance between the voltage electrode 12 and the surface to be processed of the substrate 20 is likely to vary. However, when the projecting dimension S of the ground electrode 10 with respect to the voltage electrode 12 is larger than the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12 (S> VG), the substrate 20 is bent and the ground electrode 10 is bent. Even when in contact with the substrate, the distance VS between the voltage electrode 12 and the substrate 20 can always be larger than VG.

  The second advantage is that the leakage of the electric field to the outside of the ground electrode 10 can be reduced as much as possible, the ions generated in the plasma can be collected on the ground electrode 10, and plasma irradiation mainly based on radical species is possible. Become. Thereby, even if the integrated circuit is formed on the substrate 20, it is possible to suppress problems such as electrostatic breakdown of the integrated circuit due to ion damage or the like.

  As described above, in the plasma processing apparatus according to the fifth embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is the minimum gap of the gap between the ground electrode 10 and the voltage electrode 12. It is larger than the dimension VG (VS> VG). Thus, by increasing VS as compared with VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with the plasma flow from the gas outlet 24.

  Therefore, according to the plasma processing apparatus according to the fifth embodiment, even when the substrate 20 is a semiconductor substrate or a conductive substrate under a relatively high pressure of, for example, 10 Torr or more, the surface of the substrate 20 is uniform. Thin film deposition and processing are possible.

  In the plasma processing apparatus according to the fifth embodiment, the ground electrode 10 protrudes in the direction toward the substrate 20 with respect to the voltage electrode 12, and the protrusion dimension S of the ground electrode 10 with respect to the voltage electrode 12 is equal to the voltage of the ground electrode 10. It is larger than the minimum gap dimension VG of the gap with the electrode 12 (S> VG). Thereby, even when the distance between the voltage electrode 12 and the surface to be processed of the substrate 20 varies, the condition of VS> VG can be reliably maintained. In addition, a uniform thin film can be formed and processed on the surface of the substrate 20 while preventing electrostatic damage to the substrate 20.

Embodiment 6 FIG.
FIG. 9 is a schematic diagram illustrating a configuration of a plasma processing apparatus according to the sixth embodiment. In the plasma processing apparatus according to the sixth embodiment, in the plasma processing apparatus according to the first embodiment, the power source 14 includes a high frequency power source 61 and a DC power source (or pulse power source) 62. That is, the plasma processing apparatus according to the sixth embodiment has a cylindrical ground electrode 10 whose center region in the diametrical direction is a hollow portion, and is opposed to the ground electrode 10 at a substantially central portion in the hollow portion of the ground electrode 10. The cylindrical voltage electrode 12 arranged, a power source 14 for applying power to the voltage electrode 12, a gas supply unit 16 for supplying a reaction gas to the gap between the ground electrode 10 and the voltage electrode 12, and a substrate 20 as a member to be processed. A substrate base 18 is provided which holds the substrate 20 and is electrically grounded so that the surface to be processed is substantially perpendicular to the axial direction of the voltage electrode 12 and the ground electrode 10.

  Further, the inner peripheral surface of the ground electrode 10 has a different inner diameter in the central axis direction of the ground electrode 10. The inner peripheral surface of the ground electrode 10 has an inclined portion near the central portion in the central axis direction, and the inner diameter of the region of the gas inlet 22 (gas inflow side) in the central axis direction is the gas outlet 24 (gas The inner diameter of the region on the outflow side). Of the gap between the ground electrode 10 and the voltage electrode 12, the region on the gas outflow side in the central axis direction of the ground electrode 10 (the region where the gap between the ground electrode 10 and the voltage electrode 12 is narrow) Become.

  Then, grounding is performed so that the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is larger than the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12 (VS> VG). Electrode 10 and voltage electrode 12 are arranged.

  The power source 14 has a configuration in which a high frequency power source 61 as a first power source and a DC power source (or pulse power source) 62 as a second power source are connected to the voltage electrode 12 via a bias tee 63. A high-frequency signal output from the high-frequency power supply 61 whose voltage waveform is a high-frequency waveform and a DC signal output from the DC power supply 62 are applied to the voltage electrode 12 (or a high-frequency signal output from the high-frequency power supply 61 and A voltage waveform signal in which the pulse waveform output from the pulse power supply is superimposed is applied. Here, by connecting the high frequency power source 61 and the DC power source (or pulse power source) 62 to the voltage electrode 12 via the bias tee 63, the high frequency signal flows to the voltage electrode 12 side without flowing to the DC power source 62 side. The bias tee 63 has a function of causing a DC signal (or a signal having a pulse waveform) to flow into the voltage power supply 12 side without flowing into the high frequency power supply 61 side. For example, the bias tee 63 combines the high frequency signal and the DC signal to generate a voltage. It plays the role of supplying to the electrode 12. The high frequency signal output from the high frequency power supply 61 uses, for example, a range of 2 MHz to 400 MHz as the frequency band, and the pulse waveform signal has a longer period than the high frequency signal, for example, a range of several Hz to several KHz.

  By applying DC power or pulse power to the voltage electrode 12, the DC potential of the voltage electrode 12 can be controlled, and the energy of ions incident on the voltage electrode 12 can be controlled. When the power source 14 is composed of only the high frequency power source 61, the voltage electrode 12 has a negative voltage although the value varies depending on the electrode structure and the high frequency power amount. Since this voltage is determined by the amount of high-frequency power and the electrode structure, it is difficult to control the DC potential of the electrode potential of the voltage electrode 12 while fixing the high-frequency power.

Therefore, the energy of ions is controlled by applying DC power or pulse power to the voltage electrode 12. For example, a negative DC potential is increased, and a small amount of argon (He) (He) or hydrogen (H ₂ ) is used as a main gas. By adding Ar), quinocene (Xe), or krypton (Kr) and irradiating the voltage electrode 12 with argon (Ar) ions or the like, it becomes possible to remove foreign matters or oxide films attached to the voltage electrode 12. . Here, since the oxide film and foreign matters are removed by physical action, the atomic weight of the gas should be as large as possible, but considering the economics of the gas, the use of argon (Ar) is appropriate.

  Moreover, when an insulator adheres to the voltage electrode 12, the portion is charged and electric field concentration occurs, so that arc discharge is likely to occur. Since the arc discharge damages the voltage electrode 12, it is necessary to avoid the arc discharge as much as possible. Therefore, by applying a voltage having a pulse waveform to the voltage electrode 12 and inverting the potential of the voltage electrode 12, an effect of removing partial charging of the voltage electrode 12 and making arc generation difficult to occur is produced. For example, in a repetitive pulse at 100 kHz, by applying +100 V to the voltage electrode 12 for a time duty ratio of about 0.3, there is an effect of suppressing arc generation.

  As described above, in the plasma processing apparatus according to the sixth embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is the minimum gap of the gap between the ground electrode 10 and the voltage electrode 12. It is larger than the dimension VG (VS> VG). Thus, by increasing VS as compared with VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with the plasma flow from the gas outlet 24.

  Therefore, according to the plasma processing apparatus according to the sixth embodiment, even when the substrate 20 is a semiconductor substrate or a conductive substrate under a relatively high pressure of, for example, 10 Torr or more, it is uniform with respect to the surface of the substrate 20. Thin film deposition and processing are possible.

  Further, the plasma processing apparatus according to the sixth embodiment has a configuration in which the high-frequency power source 61 and the DC power source or the pulse power source 62 are connected to the voltage electrode 12 through the bias tee 63 as the power source 14. A signal obtained by combining the signal and the DC signal (or a signal obtained by combining the high-frequency signal and the pulse signal) can be applied to the voltage electrode 12. As a result, the DC potential of the voltage electrode 12 can be controlled, the energy of ions incident on the voltage electrode 12 can be controlled, and foreign matters or oxide films attached to the voltage electrode 12 can be removed by ions. Is possible.

Embodiment 7
FIG. 10 is a schematic diagram illustrating a configuration of a plasma processing apparatus according to the seventh embodiment. The plasma processing apparatus according to the seventh embodiment has a configuration in which the substrate 20 and the substrate base 18 are electrically insulated from each other in the plasma processing apparatus according to the first embodiment. That is, the plasma processing apparatus according to the seventh embodiment has a cylindrical ground electrode 10 whose central region in the diametrical direction is a hollow portion, and is opposed to the ground electrode 10 at a substantially central portion in the hollow portion of the ground electrode 10. The cylindrical voltage electrode 12 arranged, a power source 14 for applying power to the voltage electrode 12, a gas supply unit 16 for supplying a reaction gas to the gap between the ground electrode 10 and the voltage electrode 12, and a substrate 20 as a member to be processed. A substrate base 18 made of a metal material that holds the substrate 20 so that the surface to be processed is substantially perpendicular to the axial direction of the voltage electrode 12 and the ground electrode 10 and is electrically grounded; An insulator 71 is provided between the substrate base 18 and the substrate 20 so as to be electrically insulated from each other. A heater H is built in the substrate base 18.

  Further, the inner peripheral surface of the ground electrode 10 has a different inner diameter in the central axis direction of the ground electrode 10. The inner peripheral surface of the ground electrode 10 has an inclined portion near the central portion in the central axis direction, and the inner diameter of the region of the gas inlet 22 (gas inflow side) in the central axis direction is the gas outlet 24 (gas The inner diameter of the region on the outflow side). Of the gap between the ground electrode 10 and the voltage electrode 12, the region on the gas outflow side in the central axis direction of the ground electrode 10 (the region where the gap between the ground electrode 10 and the voltage electrode 12 is narrow) Become.

  Then, grounding is performed so that the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is larger than the minimum gap dimension VG of the gap between the ground electrode 10 and the voltage electrode 12 (VS> VG). Electrode 10 and voltage electrode 12 are arranged.

  The ground electrode 10, voltage electrode 12, and power source 14 constitute a plasma generator that generates plasma. The gap between the ground electrode 10 and the voltage electrode 12 is a flow path for the reaction gas supplied from the gas supply unit 16, and the gas supply unit 16 side of the gap between the ground electrode 10 and the voltage electrode 12 introduces gas. The opening 22 becomes the gas outlet 24 on the substrate 20 side, and the substrate 20 is irradiated with the plasma flow.

  By installing the insulator 71 between the substrate base 18 and the substrate 20, a capacitance component is generated between the substrate base 18 that is a ground electrode and the substrate 20 on which film formation is performed, and the substrate viewed from the voltage electrode 12. The impedance of the base 18 can be changed. By changing the impedance, the waveform of the voltage and current applied to the substrate 20 can be changed, and the electrical damage to the substrate 20 can be arbitrarily adjusted. Thereby, the electric damage to the board | substrate 20 can be suppressed and the film-forming to the board | substrate 20 can be performed.

  Further, for example, a quartz plate can be used as the insulator 71, and the plate thickness is preferably about 0.5 mm to 3 mm. If the thickness of the insulator 71 is greater than this, a temperature gradient is generated by the insulator 71 when the substrate 20 is heated by the heater H built in the substrate stand 18, so that it is difficult to control the temperature of the substrate 20. It becomes.

  As described above, in the plasma processing apparatus according to the sixth embodiment, the minimum gap dimension VS of the gap between the voltage electrode 12 and the surface to be processed of the substrate 20 is the minimum gap of the gap between the ground electrode 10 and the voltage electrode 12. It is larger than the dimension VG (VS> VG). Thus, by increasing VS as compared with VG, even when the substrate 20 is a semiconductor substrate or a conductive substrate, the substrate is uniformly irradiated with the plasma flow from the gas outlet 24.

  Therefore, according to the plasma processing apparatus according to the sixth embodiment, even when the substrate 20 is a semiconductor substrate or a conductive substrate under a relatively high pressure of, for example, 10 Torr or more, it is uniform with respect to the surface of the substrate 20. Thin film deposition and processing are possible.

  Further, according to the plasma processing apparatus of the seventh embodiment, the substrate base 18 and the substrate 20 are electrically connected by being arranged between the substrate base 18 and the substrate 20 made of an electrically grounded metal material. An insulator 71 is provided for insulation. As a result, the impedance of the substrate base 18 viewed from the voltage electrode 12 can be changed, the waveform of the voltage and current applied to the substrate 20 can be changed, and the electrical damage to the substrate 20 is adjusted to form a film. It becomes possible.

  As described above, the plasma processing apparatus according to the present invention is used when performing plasma processing such as film formation on a target member having a low resistance value such as a semiconductor or conductivity under the condition that the gas pressure of the reaction gas is high. Useful.

DESCRIPTION OF SYMBOLS 10 Ground electrode 12 Voltage electrode 12a Cylindrical protrusion 14 Power supply 16 Gas supply part 18 Substrate stand 20 Substrate 22 Gas inlet 24 Gas jet 26 Plasma generating part 28 Insulating film 28a Insulator 30 Plasma flow 32 DC voltage source 34 AC Voltage source 36 Vacuum vessel 38 Vacuum pump 40 Pressure regulating valve 42 Suction tube 44 Insulator 46 Silicon film 48 Gas flow path 50 Heat sink 52 Pressure gauge 61 High frequency power supply 62 DC power supply (pulse power supply)
63 Bias tee 71 Insulator

Claims (11)

A plasma generator for generating plasma in a gap between the first electrode and the grounded second electrode; a power source for applying electric power to the first electrode; and a reactive gas in the gap between the first electrode and the second electrode. A gas supply source for supplying the electric power to the first electrode by the power source to generate an electric field in the gap between the first electrode and the second electrode. A plasma flow in which the reaction gas is converted into plasma by circulating the reaction gas through a gap between two electrodes is arranged so that the direction of ejection of the plasma flow from the plasma generator is substantially perpendicular to the surface to be processed. A plasma processing apparatus for irradiating the processed member,
The minimum gap size of the gap between the first electrode and the surface to be processed is smaller than the minimum gap size of the gap between the first electrode and the second electrode in the vicinity of the jetting portion for jetting the plasma flow in the plasma generator. Being big,
A plasma processing apparatus. An insulating film is coated on a surface of at least one of the first electrode and the second electrode facing the other electrode;
The plasma processing apparatus according to claim 1. Irradiating the surface to be processed with the plasma flow to form a film containing the component of the reactive gas on the surface to be processed;
The plasma processing apparatus according to claim 1. The surface of at least one of the first electrode and the second electrode facing the other electrode is coated with a material having substantially the same composition as the film to be formed,
The plasma processing apparatus according to claim 3. A plurality of the plasma generators, simultaneously irradiating the plasma flow from the plurality of plasma generators to the surface to be processed;
The plasma processing apparatus according to claim 1. Cooling at least one of the first electrode and the second electrode;
The plasma processing apparatus according to claim 1. The gas pressure of the reaction gas flowing through the gap between the first electrode and the second electrode is greater than the outside air pressure outside the gap between the first electrode and the second electrode;
The plasma processing apparatus according to claim 1. The plasma generator and the member to be processed are disposed in the atmosphere, and the plasma flow is irradiated from the plasma generator to the surface to be processed in the air atmosphere;
The plasma processing apparatus according to claim 7. The second electrode protrudes in the direction of the surface to be processed with respect to the first electrode, and the protrusion dimension of the second electrode with respect to the first electrode is the minimum gap of the gap between the first electrode and the second electrode Be larger than the dimensions,
The plasma processing apparatus according to claim 1. The power source includes a first power source that outputs power having a high-frequency waveform as a voltage waveform, and a second power source that outputs power having a pulse waveform whose cycle is longer than that of the high-frequency waveform as a DC power or a voltage waveform.
The plasma processing apparatus according to claim 1. An insulator is disposed on an electrically grounded holding member that holds the member to be processed such that a jet direction of the plasma flow from the plasma generator is substantially perpendicular to the surface to be processed. Being held through,
The plasma processing apparatus according to claim 1.