JP2008198541A - Plasma processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing device in which a plasma processing can be carried out efficiently. <P>SOLUTION: The plasma processing device 1 is provided with an impressing electrode 2, a pallet (a first electrode) 4 on which a workpiece 100 is mounted and has a function as a counter electrode of the impressing electrode 2 as well, a gas supplying means 11 for supplying a plasma processing gas and a first circuit (a power source) for impressing a voltage between the impressing electrode 2 and the pallet 4. On a bottom surface 63 of a table 6 on which the pallet 4 is mounted, there is arranged an oscillator 9 which has a power adjustment means 85 for adjusting an amount of voltage to be impressed between the impressing electrode 2 and the pallet 4 and controlling means for controlling the operation of the power adjustment means 70, and when a processing surface 110 of the workpiece 100 is processed while the pallet 4 and the workpiece 100 are integrally oscillated by the oscillator 9, the power adjustment means 85 is made to work by the controlling means 70. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus for plasma processing a workpiece.

2. Description of the Related Art Plasma processing apparatuses that generate plasma, process the surface of a substrate (workpiece), which is an object to be processed (plasma processing), and perform surface modification of the substrate are known.
Such a plasma processing apparatus has a pair of electrodes that are vertically opposed to each other via a substrate, and supplies a predetermined gas to a gap between one electrode of the pair of electrodes and the substrate. However, a voltage is applied between the pair of electrodes to cause discharge, thereby generating plasma. In the generated plasma, electrons accelerated by an electric field collide with gas molecules to generate active species such as excited molecules, radical atoms, positive ions, and negative ions. A part of these active species undergoes various reactions on or near the surface of the substrate, so that the surface of the substrate is modified (for example, see Patent Document 1).

  By the way, in order to efficiently perform plasma processing on the surface of the substrate without depending on changes in the temperature of the atmosphere during the plasma processing, active species involved in surface modification are allowed to stay near the surface of the substrate for a long time. In other words, it is important to contact the substrate surface for a long time. However, the active species generated between the pair of electrodes diffuses between the electrodes and in the chamber, so that it is difficult for the active species to stay locally for a long time near the surface of the substrate. The actual situation is that the improvement of this has not been sufficiently achieved.

Japanese Patent Laid-Open No. 7-85997

  The objective of this invention is providing the plasma processing apparatus which can perform a plasma processing efficiently.

Such an object is achieved by the present invention described below.
The plasma processing apparatus of the present invention includes a first electrode and a second electrode arranged so as to face each other with a workpiece interposed therebetween,
Gas supply means for supplying a gas for generating plasma on the surface to be processed of the workpiece;
A power supply unit that applies a voltage between the first electrode and the second electrode so as to activate the gas supplied by the gas supply means to generate plasma;
A plasma processing apparatus for processing the surface to be processed with plasma generated by the operation of the gas supply means and the power supply unit,
A vibrator that generates a vibration wave in a plasma generation region where the plasma is generated by vibrating at least one of the first electrode, the second electrode, and the workpiece;
Power adjusting means for adjusting the magnitude of the voltage applied between the first electrode and the second electrode;
Control means for controlling the operation of the power adjustment means,
The control means is configured to operate the power adjustment means to adjust the magnitude of the voltage applied between the first electrode and the second electrode.

  In the plasma processing apparatus having such a configuration, by generating the vibration wave by the vibrator, the chance of collision between the electron accelerated by the electric field and the constituent material of the gas increases, and the activation efficiency of the gas is improved. . Furthermore, by adjusting the magnitude of the voltage applied between the first electrode and the second electrode, the plasma density in the plasma generation region is set to a magnitude that allows efficient plasma processing. Can do.

In the plasma processing apparatus of the present invention, distance detection means for detecting a distance between the surface to be processed of the workpiece and the surface facing the first electrode or the second electrode facing the surface to be processed;
Moving means for defining a separation distance between the surface to be processed of the workpiece and the facing surface by moving the first electrode or the second electrode;
Prior to processing the surface to be processed of the workpiece, based on the information from the distance detection means, the control means operates the moving means to adjust the separation distance, whereby the separation distance is set. It is preferable that the magnitude is set such that a standing wave is generated between the surface to be processed of the workpiece and the facing surface.
Thereby, a standing wave can be generated between the surface to be processed and the facing surface, and plasma can be unevenly distributed in a region corresponding to a node of the standing wave.

In the plasma processing apparatus of the present invention, it is preferable that the standing wave is generated between the surface to be processed of the workpiece and the facing surface in a direction substantially orthogonal to the surface to be processed of the workpiece.
In the plasma processing apparatus of the present invention, it is preferable that the control means performs control so that the node of the standing wave is positioned on a surface to be processed of the workpiece.
As a result, the active species generated in the plasma receives a force due to the acoustic radiation pressure (standing wave), moves to the vicinity of the surface to be processed of the workpiece, and is captured at this position. Accordingly, the active species stays in the vicinity of the surface to be processed of the workpiece for a long time and reacts sufficiently with the surface to be processed. As a result, good plasma treatment can be efficiently performed on the surface to be processed.

The plasma processing apparatus of the present invention includes sound pressure detecting means for detecting a change in sound pressure between the surface to be processed of the workpiece and the opposite surface during processing of the surface to be processed of the workpiece by the plasma. ,
The control means obtains the magnitude of positional deviation of the node of the standing wave from the processing surface based on the amount of change in the sound pressure detected by the sound pressure detection means,
It is preferable that the density of the plasma on the surface to be processed is kept constant by operating the power adjusting means according to the magnitude of the positional deviation.
Thereby, the plasma processing of the surface to be processed can be performed more efficiently, and the uniform plasma processing can be performed over the entire surface to be processed.

In the plasma processing apparatus of the present invention, during the processing of the surface to be processed of the workpiece by the plasma, temperature detection means for detecting a temperature change in the region where the plasma is generated, and the thickness of the workpiece by the plasma A thickness detecting means for detecting a change,
The control unit is configured to detect a positional deviation of the node of the standing wave from the surface to be processed based on the temperature change and the thickness change detected by the temperature detection unit and the thickness detection unit, respectively. For the size of
It is preferable that the plasma density on the surface to be processed is kept constant by operating the power adjusting means in accordance with the magnitude of the displacement.
Thereby, the plasma processing of the surface to be processed can be performed more efficiently, and the uniform plasma processing can be performed over the entire surface to be processed.

In the plasma processing apparatus of the present invention, it is preferable that the frequency of the standing wave is set within a range of 1 × 10 ⁵ to 1 × 10 ⁸ Hz.
As a result, a larger acoustic radiation pressure can be obtained in the standing wave generated between the surface to be processed and the opposite surface, and this force causes the active species generated in the plasma to move near the surface to be processed. You can stay for a long time.

In the plasma processing apparatus of the present invention, it is preferable to generate a standing wave between the surface to be processed and the facing surface after generating plasma between the surface to be processed and the facing surface.
As a result, plasma is generated prior to the formation of gas density due to standing waves. As a result, active species are continuously supplied to the surface to be processed, and plasma processing of the surface to be processed can be performed more smoothly.

In the plasma processing apparatus of the present invention, the workpiece is placed on the first electrode,
It is preferable that the first electrode and the workpiece are vibrated integrally by the vibrator.
With such a configuration, it is possible to increase the chance of collision between the electron accelerated by the electric field and the constituent material of the gas.

In the plasma processing apparatus of the present invention,
The workpiece is placed on the first electrode;
Preferably, the second electrode is vibrated by the vibrator.
With such a configuration, it is possible to increase the chance of collision between the electron accelerated by the electric field and the constituent material of the gas.

In the plasma processing apparatus of the present invention, the gas supply means includes at least one nozzle that is provided through the second electrode and jets the gas between the second electrode and the workpiece. Is preferred.
In the gas supply means having such a configuration, gas is ejected from the second electrode side to the workpiece side by the nozzle, so that active species generated in the plasma ride on this gas flow toward the workpiece side. Flowing. For this reason, there is a concern that the active species may diffuse to the edge side of the workpiece after hitting the surface to be processed. On the other hand, according to the present invention, active species are trapped near the surface of the workpiece, so even if the gas supply means has such a configuration, the active species stays near the surface of the workpiece for a long time. Can be efficiently performed.

Hereinafter, a plasma processing apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
FIG. 1 is a cross-sectional view (partially including a block diagram) schematically showing a first embodiment of a plasma processing apparatus of the present invention, and FIG. 2 is a diagram showing an application electrode and a workpiece provided in the plasma processing apparatus shown in FIG. FIG. 3 is a block diagram showing a circuit configuration of the plasma processing apparatus shown in FIG. 1, and FIG. 4 is a diagram showing a workpiece covered by the plasma processing apparatus shown in FIG. It is a flowchart of the processing operation with respect to a processing surface. In the following description, the upper side in FIGS. 1 and 2 is referred to as “upper” and the lower side is referred to as “lower”.

  As shown in FIG. 1, the plasma processing apparatus 1 is an apparatus that generates plasma and plasma-processes a processing target (surface) 110 of a workpiece (substrate) 100, for example, a processing target, using the plasma. Application electrode 2 and pallet (first electrode) 4 disposed so as to face each other through workpiece 100, dielectric layer 3 disposed on the surface of application electrode 2 on the side facing workpiece 100, and pallet 4 between the application electrode 2 and the pallet 4, the table 6 that supports 4, the vibrator 9 that is disposed on the surface of the table 6 opposite to the pallet 4 and vibrates by applying a voltage. A first circuit (power supply unit) 8 for applying a voltage, a second circuit 10 for applying a voltage to the vibrator 9, a gas supply means 11 for supplying a gas for generating plasma, a dielectric layer 3, Separation distance from pallet 4 A moving means 5 for defining a, and a distance detecting means 53 for detecting the distance between the dielectric layer 3 and the pallet 4.

Hereinafter, the configuration of each part of the plasma processing apparatus 1 will be described.
The material of the pallet 4 is not particularly limited as long as the pallet 4 can function as an electrode. For example, a simple metal such as copper, aluminum, iron, silver, stainless steel, and the like. Examples include conductive materials having good conductivity, such as various alloys such as steel, brass, and aluminum alloys, intermetallic compounds, and various carbon materials. Moreover, the pallet 4 may be comprised with the laminated body which laminated | stacked two or more layers each comprised from a different electroconductive material.

In the workpiece 100, the processing target surface 110 exposed in the recess 41 is processed by the plasma processing apparatus 1 of the present invention while being accommodated in the recess 41.
The workpiece 100 is not particularly limited. For example, various glasses such as quartz glass and non-alkali glass, various ceramics such as alumina, silica, and titania, various semiconductor materials such as silicon, gallium arsenide, and ITO, and Examples include substrates made of various plastics (resin materials) such as polyethylene, polypropylene, polystyrene, polycarbonate, polyethylene terephthalate, polytetrafluoroethylene, polyimide, liquid crystal polymer, phenol resin, epoxy resin, and acrylic resin. It is done.

Examples of the shape of the workpiece 100 include a plate shape (substrate), a layer shape, and a film shape. As such a workpiece | work 100, the display panel used for a liquid crystal display device, an organic electroluminescent display device, etc., a glass chip, a semiconductor chip, a ceramic chip etc. are mentioned, for example.
Further, the shape of the workpiece 100 (the shape in plan view) is not limited to a rectangular shape, and may be, for example, a circular shape or an elliptical shape.
Although the thickness of the workpiece | work 100 is not specifically limited, Usually, it is preferable that it is about 0.3-1.2 mm, and it is more preferable that it is about 0.5-0.7 mm.

The table 6 supports and fixes the pallet 4.
The table 6 has a concave portion 61 opened on the upper surface thereof, and the pallet 4 is fixed in the horizontal direction in the concave portion 61 and is integrated with the vibration of the table 6 in the vertical direction (by a vibrator 9 described later). It is inserted (inserted) in such a way that it can vibrate in the vibration direction. In this case, the depth of the recess 61 is preferably equal to the thickness of the pallet 4. That is, it is preferable that the upper surface 62 of the table 6 and the upper surface 42 of the pallet 4 inserted into the recess 61 are configured as a flat surface (continuous surface) having substantially no step. Thus, when plasma processing is performed by the plasma processing apparatus 1, the distance between the lower surface of the dielectric layer 3 and the upper surface 62 of the table 6 and the distance between the lower surface of the dielectric layer 3 and the upper surface 42 of the pallet 4 are made equal. Thus, a standing wave to be described later can be reliably generated between them, so that the workpiece 100 can be uniformly and satisfactorily subjected to plasma treatment.
The constituent material of the table 6 is not particularly limited, but various insulating materials are preferably used. For example, various glasses such as quartz glass and alkali-free glass, various ceramics such as silicon dioxide and silicon nitride, polyethylene terephthalate And various plastics (resin materials) such as polyimide.

In the present embodiment, the vibrator 9 is disposed on the lower surface of the table 6 (on the surface opposite to the side on which the pallet 4 is placed) while being connected to the second circuit 10. The configuration of the vibrator 9 and the second circuit 10 will be described in detail later.
The application electrode 2 functions as a counter electrode of the pallet 4 and generates an electric field between the application electrode 2 and the pallet 4 via the workpiece 100 and the dielectric layer 3.
In this embodiment, the application electrode 2 has a substantially rectangular plate shape so that the lower surface (the surface facing the workpiece 100 via the dielectric layer 3) is a flat surface and corresponds to the shape of the pallet 4. The lower surface of the application electrode 2 (the surface facing the workpiece 100) and the surface to be processed 110 of the workpiece 100 are installed so as to be substantially parallel.
In this embodiment, the application electrode 2 and the pallet 4 described above constitute a pair of parallel plate electrodes.

The constituent material of the application electrode 2 is not particularly limited as long as the application electrode 2 can exhibit the function as an electrode, as in the case of the pallet 4. For example, copper, aluminum, iron, Examples thereof include materials having good conductivity such as simple metals such as silver, various alloys such as stainless steel, brass and aluminum alloys, intermetallic compounds, and various carbon materials.
Moreover, the application electrode 2 may be comprised by the laminated body which laminated | stacked two or more layers comprised by the different electroconductive material. Further, the conductive material constituting the application electrode 2 may be the same as or different from the constituent material of the pallet 4.

Note that the planar shape of the application electrode 2 is not limited to the above-described square shape, and may be, for example, a circle, an ellipse, or other irregular shapes. There may be a plurality of application electrodes 2.
The dielectric layer 3 is disposed (bonded) on the lower surface of the application electrode 2 (the surface facing the workpiece 100).
In the present embodiment, the application electrode 2 and the dielectric layer 3 constitute a second electrode, and the lower surface of the dielectric layer 3 forms the facing surface 30 facing the surface 110 to be processed of the workpiece 100. Constitute.

By providing this dielectric layer 3, it is possible to prevent arc discharge from occurring when a voltage is applied between the application electrode 2 and the pallet 4 to generate plasma, and a good (uniform) glow discharge is generated. Can be generated. As a result, good plasma can be generated between the application electrode 2 and the pallet 4.
The constituent material of the dielectric layer 3 is not particularly limited as long as the dielectric layer 3 can function as a dielectric. For example, polytetrafluoroethylene, polyethylene terephthalate, etc. Examples thereof include various plastics (resin material), various glasses such as quartz glass, and inorganic oxides. Examples of the inorganic oxide include metal oxides such as Al ₂ O ₃ , SiO ₂ , ZrO ₂ , and TiO ₂ , and composite oxides such as BaTiO ₃ (barium titanate).

In addition, by using a dielectric having a relative dielectric constant of 10 or more at 25 ° C. as a constituent material of the dielectric layer 3, it is possible to generate a high-density plasma at a low voltage, and the processing efficiency of the plasma processing is further improved. The advantage of improvement is also obtained.
Moreover, the upper limit of the relative dielectric constant of the dielectric layer 3 is not particularly limited, but those having a relative dielectric constant of about 10 to 100 are preferable. The dielectric having a relative dielectric constant of 10 or more corresponds to a metal oxide such as ZrO ₂ or TiO ₂ or a composite oxide such as BaTiO ₃ .

Although the thickness of the dielectric material layer 3 is not specifically limited, It is preferable that it is about 0.01-4.0 mm, and it is more preferable that it is about 1.0-2.0 mm. If the dielectric layer 3 is too thick, a high voltage may be required to generate plasma (desired discharge). If it is too thin, dielectric breakdown occurs during voltage application and arc discharge occurs. There is a fear.
In the present invention, the arrangement of the dielectric layer 3 may be omitted. In this case, the application electrode 2 forms a second electrode, and the lower surface of the application electrode 2 forms an opposing surface that faces the surface 110 to be processed.

The gas supply unit 11 supplies a gas for generating plasma between the application electrode 2 and the workpiece 100.
In the present embodiment, this gas supply means corresponds to the seven nozzles (gas ejection pipes) 16 provided through the application electrode 2 and the dielectric layer 3 (second electrode), and the nozzles 16. A gas supply pipe 12 having a provided branch pipe 121 is connected to the upstream end side of the gas supply pipe 12, filled with a predetermined gas (processing gas + carrier gas), and supplied between the application electrode 2 and the workpiece 100. A gas cylinder (gas supply source) 13 and a regulator (flow rate adjusting means) 14 for adjusting the flow rate of the gas supplied from the gas cylinder 13.

The regulator 14 is disposed downstream of the gas cylinder 13 (on the nozzle 16 side). Further, on the downstream side of the regulator 14 of the gas supply pipe 12, a valve 15 (flow path opening / closing means) 15 that opens and closes the flow path in the gas supply pipe 12 is provided. Controls whether gas is supplied to the side. The gas supply pipe 12 is divided into a plurality of branch pipes 121 on the downstream side of the valve 15, and the downstream ends of the branch pipes 121 are connected to the corresponding nozzles 16.
The number of nozzles 16 is not limited to seven as in the present embodiment, and it is sufficient that at least one nozzle is provided, and the number may be more than seven or less.

  In the gas supply means 11 having such a configuration, when the gas is sent from the gas cylinder 13 with the valve 15 opened, the gas flows in the gas supply pipe 12 and the flow rate is adjusted by the regulator 14. The current is diverted to 121. Thereafter, each nozzle 16 is ejected (supplied) between the application electrode 2 (dielectric layer 3) and the workpiece 100. According to the gas supply means 11 having such a configuration, that is, the gas is supplied between the application electrode 2 and the workpiece 100 by the plurality of nozzles 16 provided penetrating the application electrode 2 and the dielectric layer 3. Thus, the gas can be supplied more uniformly between the application electrode 2 and the workpiece 100. As a result, plasma can be efficiently generated between them, and the plasma treatment for the workpiece 100 can be performed more uniformly and satisfactorily.

The gas supplied between the application electrode 2 and the workpiece 100 is not particularly limited. For example, a processing gas such as O ₂ gas (a gas that mainly contributes to plasma processing) and a carrier gas such as He gas are used. A mixed gas consisting of is preferably used. In the present specification, the “carrier gas” refers to a gas introduced for starting discharge and maintaining discharge.
In the present embodiment, the gas cylinder 13 is filled with a mixed gas (processing gas + carrier gas), but the processing gas and the carrier gas are filled in different gas cylinders, and the gas supply pipe 12 is in the middle. A configuration in which these are mixed at a predetermined mixing ratio may be employed.
Further, the processing gas is not limited to the O ₂ gas as described above as long as it is a gas that generates plasma by applying a voltage (discharge) between the application electrode 2 and the pallet 4. Various gases can be used.

As the other processing gas, for example, the following gas can be used.
For example, in the plasma processing aiming to make the surface 110 of the workpiece 100 water repellent (liquid repellent), CF ₄ , C ₂ F ₆ , C ₃ F ₆ , CClF ₃ , SF _6, etc. are used as processing gases. The fluorine atom-containing compound gas is used.
Further, in the plasma treatment for the purpose of making the surface 110 to be treated hydrophilic (lyophilic), oxygen gas-containing compounds such as O ₃ , H ₂ O, and air, and nitrogen such as N ₂ and NH ₃ are used as treatment gases. Those containing one or both of an atom-containing compound and a sulfur atom-containing compound such as SO ₂ and SO ₃ are used. Thereby, hydrophilic functional groups, such as a carbonyl group, a hydroxyl group, an amino group, are formed in the to-be-processed surface 110 of the workpiece | work 100, surface energy can be made high and a hydrophilic surface can be obtained. Alternatively, a hydrophilic polymer film can be deposited (formed) using a polymerizable monomer having a hydrophilic group such as acrylic acid or methacrylic acid.

Further, in the plasma treatment for the purpose of adding an electrical and optical function to the surface 110 to be processed of the workpiece 100, a metal oxide thin film such as SiO ₂ , TiO ₂ , SnO ₂ or the like is used as the surface 110 to be processed of the workpiece 100. In order to form a film, a material containing a metal metal-hydrogen compound such as Si, Ti, or Sn, a metal-halogen compound, a metal alkoxide (organometallic compound), or the like is used.

Further, for example, a halogen-based gas is used in plasma processing for the purpose of etching processing or dicing processing, and for example, oxygen-based gas is used for plasma processing for the purpose of resist processing or removal of organic contamination. In plasma processing for the purpose of surface cleaning and surface modification, for example, an inert gas such as Ar or N ₂ is used as a processing gas, and surface cleaning or surface modification is performed with plasma of the inert gas.

Further, the carrier gas is not limited to He gas. In addition, for example, a rare gas such as Ne, Ar, or Xe, N ₂ gas, or the like can be used, and these may be used alone or in combination of two or more. But it can also be used.
Note that the ratio (mixing ratio) of the processing gas in the mixed gas varies depending on the type of plasma processing, but if the processing gas ratio is too large, it is difficult to generate plasma (discharge) or the efficiency of the plasma processing. For example, the ratio of the processing gas in the mixed gas is preferably about 1 to 10%, more preferably about 5 to 10%.
The flow rate of the gas to be supplied is appropriately determined according to the type of gas, the purpose of the plasma treatment, the degree of treatment, etc., and is not particularly limited, but it is usually preferably about 30 SCCM to 3 SLM.

  A predetermined gas is supplied between the dielectric layer 3 and the workpiece 100 (gap) using the gas supply means 11, and a predetermined voltage, for example, a high-frequency voltage (voltage) is applied between the application electrode 2 and the pallet 4. ) Is applied, an electric field is generated between the application electrode 2 and the pallet 4, that is, between the dielectric layer 3 and the workpiece 100, thereby generating a discharge, that is, a glow discharge (barrier discharge). By this discharge, the supplied gas is activated (ionization, ionization, excitation, etc.), and plasma is generated. And the to-be-processed surface 110 of the workpiece | work 100 is processed (plasma process) by the active species 20, such as the excited molecule, radical atom, positive ion, and negative ion which arose in this plasma.

The moving means 5 defines a separation distance between the dielectric layer 3 and the pallet 4, that is, a separation distance between the facing surface 30 and the surface to be processed 110.
Examples of the moving means 5 include those using a cylinder such as an air cylinder or a hydraulic cylinder, and those using an actuator such as a motor and a piezoelectric element. In this embodiment, FIG. 1 and FIG. As shown in FIG. 4, a cylinder 50 is used as the moving means 5.

In this embodiment, the table 6 is supported via two cylinders 50 that operate in conjunction with each other.
The cylinder 50 includes a cylinder body 51 and a piston 52 that is positioned on the upper end side of the cylinder 50 and can be expanded and contracted with respect to the cylinder body 51. The cylinder body 51 is grounded and fixed at the lower end side, and the piston 52 is fixed to the table 6 at the upper end side. By setting it as this structure, the cylinder 50 can adjust the length by extending / contracting the piston 52 by hydraulic pressure or air pressure, respectively.
Therefore, the to-be-processed surface 110 can be moved with respect to the opposing surface 30 by extending and contracting the two cylinders 50 having such a configuration. Thereby, the separation distance between the processing target surface 110 and the facing surface 30 can be adjusted (defined) to a desired size.

A distance detecting means 53 is provided on the upper surface 42 side of the pallet 4.
The distance detection unit 53 has a function of detecting a separation distance between the processing target surface 110 and the facing surface 30.
In this embodiment, the distance detection unit 53 is provided such that the detection unit (not shown) of the distance detection unit 53, the upper surface 42 of the pallet 4, and the processing target surface 110 of the workpiece 100 form a flat surface. It has been. With such a configuration, the separation distance between the processing target surface 110 and the facing surface 30 can be reliably measured.

  Such a distance detection means 53 is not particularly limited, but, for example, a laser that irradiates the facing surface 30 with a laser beam and measures the reflected light to detect a separation distance between the processing surface 110 and the facing surface 30. A displacement meter or the like can be used. According to the distance detecting means constituted by the laser displacement meter, the separation distance between the surface to be processed 110 and the facing surface 30 can be detected relatively easily and reliably.

  Such a cylinder 50 and the distance detection means 53 are each connected to the control means 70 mentioned later, as shown in FIG. Such a control means 70 operates the cylinder 50 on the basis of the measurement value (information) detected by the distance detection means 53, and thereby the desired separation distance between the processing target surface 110 and the facing surface 30 is obtained. The interval (size) can be set.

The distance between the dielectric layer 3 and the workpiece 100 (the distance between the facing surface 30 and the surface to be processed 110) includes the output of a high-frequency power source 82 described later, the type of plasma treatment applied to the workpiece 100, the thickness of the workpiece 100, and the like. However, it is usually preferably set to about 0.3 to 2 mm, more preferably about 0.3 to 1 mm. Thereby, a necessary and sufficient electric field can be generated between the dielectric layer 3 and the workpiece 100.
Note that the distance between the dielectric layer 3 and the workpiece 100 is one of the important conditions for performing a uniform and appropriate plasma treatment on the surface to be processed 110 (including the type of gas, the flow rate, the applied voltage, etc.). This is also an important condition for generating a standing wave, which will be described later, between the dielectric layer 3 and the workpiece 100 and positioning a node of the standing wave on the surface 110 to be processed.

  In the present embodiment, as shown in FIG. 1, a high frequency power source (power source unit) 82 is connected to the application electrode 2 via a conducting wire (cable) 81, and impedance matching is performed in the middle of the conducting wire 81. A matching box (matching unit) 84 is provided. The pallet 4 is connected to a high-frequency power source 82 through a conductive wire 81 and a switch 83 that switches between a conductive state and a non-conductive state. Furthermore, a power adjusting means 85 is connected to the high frequency power source 82.

A first circuit (power supply unit) for applying a voltage (high-frequency voltage) between the application electrode 2 and the pallet 4 by the conducting wire 81, the high-frequency power source 82, the switch 83, the matching box 84, and the power adjusting means 85. 8 is configured. A part of the first circuit 8, that is, the conductive wire 81 on the pallet 4 side is grounded.
When the switch 83 is closed, the pallet 4 is grounded through conduction of the conductive wire 81, whereby a high frequency voltage (voltage) can be applied between the pallet 4 and the application electrode 2, and when the switch 83 is opened. The conducting wire 81 is in a non-conducting state (cut-off state), no voltage is applied between the pallet 4 and the applying electrode 2, and no plasma is generated.

  The power adjusting means 85 adjusts the magnitude of the power supplied to the high frequency power supply 82, thereby adjusting the magnitude of the voltage applied between the application electrode 2 and the pallet 4, that is, the application electrode 2. It has a function of adjusting the magnitude of energy supplied between it and the pallet 4. By adopting the configuration including the power adjusting means 85, the amount of plasma generated between the application electrode 2 and the pallet 4 can be adjusted, so that the intensity of the plasma treatment for the workpiece 100 can be adjusted.

As shown in FIGS. 1 and 3, the power adjusting means 85 is connected to a control means 70 described later. The power adjustment means 85 is operated by the control means 70, and the magnitude of the voltage applied between the application electrode 2 and the pallet 4 by the high frequency power supply 82 can be adjusted.
Although not shown, the first circuit 8 may include a power frequency adjusting means (circuit) for changing the frequency of the high frequency power source 82. Thereby, the processing conditions of the plasma processing with respect to the workpiece | work 100 can be adjusted more accurately.

The frequency of the high-frequency power source 82 is not particularly limited, but is preferably about 10 to 50 MHz, and more preferably about 10 to 40 MHz.
When plasma processing is performed on the workpiece 100, the high frequency power supply 82 is activated, the switch 83 is closed, and a voltage is applied between the pallet 4 and the application electrode 2. At this time, an electric field is generated between the pallet 4 and the application electrode 2, and when gas is supplied from the gas supply means 11, discharge is generated and plasma is generated by activating this gas. .

  Since the impedance matching is performed by configuring the first circuit 8 to include the matching box 84 as in the present embodiment, the magnitude of the voltage applied between the application electrode 2 and the pallet 4 is large. When the thickness is constant, the strength of the electric field generated between the pallet 4 and the application electrode 2 is kept constant. As a result, the density of the plasma generated between them is also kept constant.

The plasma processing apparatus of the present invention includes a vibrator 9 that generates a vibration wave between the surface to be processed 110 and the facing surface 30, that is, in the plasma generation region. Hereinafter, the vibrator 9 will be described in detail.
In the present embodiment, the vibrator 9 is disposed on the lower surface 63 of the table 6, that is, on the lower side of the pallet 4 via the table 6 while being connected to the second circuit 10.

The vibrator 9 vibrates when power is supplied from the second circuit 10 to vibrate the application electrode 2 and the workpiece 100 integrally, and a vibration wave is generated between the surface to be processed 110 and the facing surface 30. (Sound wave) is generated.
In this embodiment, the vibrator 9 includes a pair of electrodes 92 and 93 and a piezoelectric body 91 provided between the pair of electrodes 92 and 93 so as to be in contact with both of them. An electrode 92 that is an upper electrode is joined to the lower surface 63 of the table 6.

The piezoelectric body 91 is made of a piezoelectric material and is formed in a plate shape. With such a configuration, when a voltage is applied between the pair of electrodes 92 and 93, the function as a deformable diaphragm can be reliably exhibited.
The piezoelectric material is not particularly limited, and for example, quartz (SiO ₂ ), barium titanate (BaTiO), lead titanate (PbTiO ₃ ), lead zirconate titanate (Pb (Zr, Ti) O ₃ ), Lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti) O ₃ ), lithium niobate (LiNbO ₃ ), lead metaniobate (PbNb ₂ O ₆ ), PZT (solid solution of lead zirconate and lead titanate) ), Piezoelectric polymer films such as polyvinylidene fluoride (PVDF), and zinc oxide (ZnO). By configuring the piezoelectric body 91 with such a piezoelectric substance, the piezoelectric body 91 can be suitably deformed when a voltage is applied between the pair of electrodes 92 and 93, and the piezoelectric body 91 can be used as a vibration plate. The function of can be demonstrated reliably.

In the present embodiment, the piezoelectric body 91 has a substantially rectangular plate shape. The shape (shape in plan view) of the piezoelectric body 91 is not limited to a rectangular shape, and may be, for example, a circular shape or an elliptical shape.
The thickness of the piezoelectric body 91 is not particularly limited, but is preferably about 0.01 to 4.0 mm, and more preferably about 0.1 to 2.0 mm.

In addition, the pair of electrodes 92 and 93 can have the same configuration as the application electrode 2 described above.
One electrode 92 of the pair of electrodes is connected to the AC power source 102 via frequency adjusting means (regulator) 74 that adjusts the frequency of the conductor (cable) 101 and the high frequency power source 102, that is, the frequency of the vibrator 9. The other electrode 93 is connected to the AC power source 102 via the conductive wire 101 and the switch 103 that switches between the conductive state and the non-conductive state, whereby the second electrode 93 for applying an AC voltage to the vibrator 9 is connected. A circuit 10 is configured.
When the switch 103 is closed, the conducting wire 101 becomes conductive, and an AC voltage can be applied between the electrodes 92 and 93. When the switch 103 is opened, the conducting wire 101 becomes non-conductive (cut-off state), and the electrodes 92 and 93 No voltage is applied between them.

  When the vibrator 9 is vibrated, the AC power source 102 and the frequency adjusting unit 74 are operated, the switch 103 is closed, and an AC voltage is applied to the piezoelectric body 91. At this time, the piezoelectric body 91 expands and contracts (deforms) up and down at a predetermined frequency by the piezoelectric effect, and by following the deformation, the electrode 92, the table 6, the pallet 4, and the workpiece 100 disposed on the upper side thereof. Vibrates up and down. Thus, when a gas is supplied between the workpiece 100 and the dielectric layer 3 in a state where the pallet 4 and the workpiece 100 vibrate integrally, the space between the dielectric layer 3 and the workpiece 100 also vibrates. Therefore, the chance of collision between the electron accelerated by the electric field and the constituent material of the gas increases, and the activation efficiency of the gas is improved. As a result, the plasma processing of the processing target surface 110 can be performed efficiently.

  Then, by adjusting the frequency of the high-frequency power source 102 by the frequency adjusting means 74, that is, by adjusting the frequency of the vibrator 9, a periodic roughness (sound wave) is formed in the space between the dielectric layer 3 and the workpiece 100. ) Can be generated at a desired frequency. This sound wave (traveling wave) travels in a direction substantially orthogonal to the surface 110 to be processed and is reflected by the facing surface 30 to generate a reflected wave. Therefore, when the distance between the facing surface 30 and the surface to be processed 110 is adjusted by the moving means 5, the reflected wave and the traveling wave are overlapped, and the space between the surface to be processed 110 and the facing surface 30 is shown in FIG. As shown, a standing wave W substantially perpendicular to the surface to be processed 110 is generated.

Here, in the standing wave W, sound pressure nodes W _{1 and} antinodes W ₂ are alternately present at intervals of ¼ wavelength with respect to the propagation direction of the sound wave, and the position of the node W ₁ is a change in density. It is a stable place with little or no change in density.
In general, when a minute object that is sufficiently smaller than the wavelength of a sound wave is introduced into the sound field of such a standing wave W, the object moves from the sound pressure antinode W ₂ toward the node W ₁ (acoustic radiation pressure). subjected to a force) according to a phenomenon that is observed is known that is trapped in position (region) corresponding to a node W ₁ of the sound pressure.
Therefore, when plasma is generated between the processing target surface 110 where such a standing wave is generated and the facing surface 30, the plasma (active species 20) can be unevenly distributed in a region corresponding to the node W _1. It becomes like this.

On the other hand, a constant that is an integer multiple of the wavelength of the standing wave is n, the frequency of the sound wave is f [Hz], the speed of the sound wave (in the air, 273 K, 1 atm) is C ₀ [m / sec], and faces the surface 110 to be processed. When the separation distance (gap) from the surface 30 is L [mm] and the gas temperature (that is, the temperature in the region where the plasma is generated) is T [K], the period n satisfies the relationship of the following formula 1. Therefore, the positions of the nodes W _{1 and the} antinodes W ₂ of the standing wave W are changed by appropriately setting at least one parameter among the frequency f, the separation distance L, and the gas temperature T, for example. That is, by setting the parameters appropriately, it is possible to move the positions of the nodes W ₁ and ventral W ₂ at an arbitrary position.
f = nC ₀ / 2L · √ (T / 273) · 10 ³ (1)

Therefore, in a state in which plasma is generated between the workpiece 100 and the electrode 2, so that the position of the section W ₁ of the workpiece 100 side, coincides with the treatment surface 110 of the workpiece 100, the frequency f, the distance L And at least one parameter of the gas temperature T is set to generate the standing wave W. As a result, the active species 20 generated in the plasma receives a force due to the acoustic radiation pressure (standing wave) and moves to the vicinity of the surface 110 to be processed of the workpiece 100 (position of the node W ₁ of the standing wave W). Captured at this position. Therefore, the active species 20 stays in the vicinity of the surface 110 to be processed of the workpiece 100 for a long time and reacts sufficiently with the surface 110 to be processed. As a result, it is possible to efficiently perform a good plasma process on the surface 110 to be processed.

Of these parameters, the gas temperature T is a parameter that varies during the processing of the surface to be processed 110. Therefore, by appropriately setting the frequency f or the separation distance L between the surface to be processed 110 and the facing surface 30. The node W ₁ can be positioned on the processing surface 110 relatively easily and reliably.
As described above, the setting (adjustment) of the separation distance between the processing surface 110 and the facing surface 30 can be performed by controlling the operation of the moving unit 5 by the control unit 70 described later.

Moreover, it is preferable to set the frequency of the standing wave W generated between the workpiece 100 and the applied electrode 2 between about 1 × 10 ⁵ to 1 × 10 ⁸ Hz, and 1 × 10 ^{5 to} 5 × 10 ^7. It is more preferable to set between about Hz. By setting the frequency within such a range, it is possible to obtain a larger acoustic radiation pressure in the standing wave generated between the surface to be processed and the opposing surface, and this force generates the activity generated in the plasma. seeds, position (with the surface to be processed) of section w ₁ can be made to stay a long time in the near.
In the present embodiment, the vibrator 9 is provided so as to overlap almost the entire workpiece 100. With this configuration, the active species 20 can be uniformly captured by the force of the acoustic radiation pressure as described above over the entire surface to be processed 110 of the workpiece 100, so that the plasma processing of the surface to be processed 110 can be performed uniformly and efficiently. It can be performed.

The operation for generating the standing wave W is preferably performed after the operation for generating plasma between the workpiece 100 and the application electrode 2. By generating the standing wave W after the plasma is generated, the plasma is generated before the air density due to the standing wave W is formed. As a result, the active species 20 is continuously supplied to the surface 110 to be processed, and the plasma processing of the surface 110 to be processed can be performed more smoothly.
Although not shown, the second circuit 10 may include a power adjustment unit for the AC power source 102. Thereby, the generation conditions of the standing wave W can be adjusted as needed.

  Further, in this embodiment, the vibrator 9 is disposed on the lower surface 63 of the table 6, but may be disposed on the upper surface 42 of the pallet 4, and may be disposed on both the lower surface 63 and the upper surface 42. You may make it do. However, if the vibrator 9 is disposed on the upper surface 42 of the pallet 4, the surface of the vibrator 9 may be exposed to the active species 20, and it is difficult to maintain the vibration characteristics. Therefore, it is preferable to arrange the vibrator 9 on the lower surface of the pallet 4 as in this embodiment.

By the way, as shown in the above formula 1, the magnitude of the constant n is the frequency f of the sound wave (vibration wave) and the region where the plasma is generated (hereinafter sometimes simply referred to as “plasma generation region”). The temperature varies according to the temperature T and the size of the separation distance L between the surface to be processed 110 and the facing surface 30.
Further, the temperature T and the separation distance L change as the plasma processing of the surface 110 to be processed proceeds. That is, the temperature T tends to increase as the plasma processing of the surface 110 to be processed proceeds, and the separation distance L varies depending on the type of plasma processing described above, but in the case of etching processing, dicing processing, or the like, for example. In the case of plasma treatment or the like for the purpose of adding a hydrophilic treatment, a liquid repellency treatment, and an electrical or optical function, the treatment applied to the treatment surface 110 is increased by the amount of the removal of the treatment surface 110. It becomes smaller by the thickness of the component.

For this reason, even if the node W _{1 of the} standing wave W is positioned on the surface 110 to be processed at the start of the plasma processing, the node W of the standing wave W varies with changes in the temperature T and the separation distance L. The position of ₁ will be displaced from the surface 110 to be processed. As a result, the number of active species present in the vicinity of the surface 110 to be processed is reduced due to a decrease in the density of the plasma. As a result, the processing efficiency of the processing target surface 110 is lowered. In order to prevent such a decrease in processing efficiency, the plasma processing apparatus 1 of the present invention is provided with a power adjusting means 85.

The power adjustment means 85 is configured to adjust the magnitude of the voltage applied between the application electrode 2 and the pallet 4 by the operation of the high-frequency power source 82. Thereby, the plasma concentration (density) of the entire plasma generation region can be adjusted. As a result, even if the node W _{1 of the} standing wave W is displaced from the processing surface 110, the power adjustment means 85 is operated to increase the plasma concentration (density) in the entire plasma generation region. The plasma density on the processing surface 110 can be kept constant. It should be noted that the magnitude of the positional deviation of the node W ₁ from the processing surface 110 and the magnitude of the voltage applied between the application electrode 2 and the pallet 4 in order to keep the plasma density on the processing surface 110 constant. The relationship can be obtained experimentally in advance.

By the plasma treatment thickness variation in the temperature rise and the treatment surface 110 by the proceeds in accordance with the positional deviation from the treatment surface 110 of the section W _1, by adjusting the concentration of plasma in the entire plasma generation region The plasma processing apparatus 1 of the present embodiment is configured as follows so that the plasma density on the processing target surface 110 is kept constant. That is, the plasma processing apparatus 1 of the present embodiment includes a power adjustment unit 85 and a sound pressure detection unit 73 that measures the positions of the nodes W ₁ and the antinodes W ₂ of the standing wave W, as shown in FIGS. And a control means 70 for controlling the operation of the power adjustment means 85. Further, the plasma processing apparatus 1 includes a temperature detection unit 71 that detects a temperature change in a region where plasma is generated, and a thickness detection unit that detects a change in thickness that occurs during processing of the processing target surface 110 by the plasma. 72 and an operation unit 75 for inputting an instruction to start plasma processing or the like.

The sound pressure detecting means 73 is movable between the surface to be processed 110 and the opposing surface 30 of the workpiece 100 in the X direction shown in FIG. 1 (a direction substantially perpendicular to the longitudinal direction of the surface to be processed 110). It is provided as such. Such sounds while moving the pressure detecting means 73 to measure the change amount of the sound pressure, based on the amount of change, the positions of the nodes W ₁ of the standing wave W can be reliably detected. That is, it is possible to determine reliably the position size of the deviation from the treatment surface 110 of the section W ₁ of the standing wave W.
Such a sound pressure detecting means 73 can be constituted by, for example, a sound pressure gauge that includes a piezoelectric element as a sensor and converts vibration of the piezoelectric element into an electric signal.

Further, in the present embodiment, the temperature detecting means 71 is provided on the facing surface 30 side of the dielectric layer 3. With this configuration, the temperature in the region between the surface to be processed 110 and the facing surface 30, that is, the temperature in the plasma generation region can be reliably measured, and the temperature in the plasma generation region generated during processing of the surface to be processed 110. A change can be reliably detected.
Such a temperature detection means 71 can be comprised with a thermocouple, a platinum resistance temperature detector, a thermistor, an infrared thermography, etc., for example. For example, according to the temperature detection means constituted by a thermocouple, a temperature change in the plasma generation region can be detected relatively easily with a simple configuration.

  A thickness detecting means 72 is provided so as to be connected to the matching box 84. This thickness detection means 72 is based on a history of changes in current or phase difference, etc., that occur because the matching box 84 matches the magnitude of impedance so that the plasma density in the plasma generation region is constant. In addition, a change in thickness that occurs during processing of the processing surface 110 is indirectly detected. By providing such a thickness detecting means 72, it is possible to detect a change in the thickness of the workpiece 100 on the surface to be processed 110, and therefore, a change in the size of the separation distance L between the surface to be processed 110 and the facing surface 30. Can be reliably detected. Note that the relationship between the history of changes in current, voltage, phase difference, and the like, and the change in thickness that occurs during processing of the processing target surface 110 can be experimentally determined in advance.

Since the temperature detecting means 71 and the thickness detecting means 72 can detect the temperature change in the plasma generation region and the change in the size of the separation distance L, respectively, based on these detection results, it is possible to determine the position of the section W ₁ of the standing waves W. That is, even by such a method, it is possible to reliably detect the magnitude of the positional deviation of the node W ₁ of the standing wave W from the processing surface 110.

The control means 70 is connected to the power adjustment means 85 and controls the operation of the power adjustment means 85 to adjust the amount of plasma generated in the plasma generation region. Thereby, the plasma density on the processing target surface 110 can be kept constant.
The control means 70 is connected to a sound pressure detection means 73, a temperature detection means 71, a thickness detection means 72, a distance detection means 53, and the like, and these measurement results (detection results) are input as needed.
The control means 70 includes, for example, a microcomputer (CPU), a sound pressure detection means 73, a temperature detection means 71, a thickness detection means 72, a memory that temporarily records (stores) measured values of the distance detection means 53, and It is composed of a time clock for generating a time signal indicating time.

  Such a control means 70 operates the power adjustment means 85 based on the measured value (output signal) measured by the sound pressure detection means 73, thereby applying a voltage applied between the application electrode 2 and the pallet 4. The size of can be changed. The magnitude of the voltage may be changed based on the measured values measured by the temperature detecting means 71 and the thickness detecting means 72 instead of the measured values measured by the sound pressure detecting means 73. However, the magnitude of the voltage may be changed on the basis of the measured values measured by both of them.

Thus, the control means 70 can change the magnitude of the voltage applied between the application electrode 2 and the pallet 4. Thereby, as the plasma processing of the surface to be processed 110 proceeds, even if the temperature T increases or the thickness of the workpiece 100 on the surface to be processed 110 changes, the node W ₁ of the standing wave W changes. Even if the position moves from the surface 110 to be processed, the plasma density on the surface 110 to be processed can be kept constant. As a result, the plasma processing of the processing target surface 110 can be performed more efficiently, and uniform plasma processing can be performed over the entire processing target surface 110.

  As the operation unit 75, for example, a touch panel including a keyboard, a liquid crystal display panel, an EL display panel, or the like can be used. In this case, the operation unit 75 displays display means (notification) for displaying (notifying) various types of information. (Means) may also be used. The information input from the operation unit 75 includes, for example, the type of processing gas used for plasma processing, the processing gas supply amount, the operating conditions of the first circuit 8, the vibration frequency of the vibrator 9, and information on the workpiece (thickness, width). Etc.).

Next, the operation (operation) of the above-described plasma processing apparatus 1 of the present invention will be described based on the flowchart shown in FIG. In the figure, S indicates each step of the flow. In the following, a case where the positional deviation of the node W ₁ of the standing wave W from the processing surface 110 is detected based on the measurement value (output signal) by the sound pressure detection means 73 will be described as a representative.
[1] First, after placing the surface to be processed 110 of the workpiece 100 on the pallet 4 (first electrode), the moving surface 5 is operated, whereby the surface to be processed 110 and the facing surface 30 are moved. of the distance L, the section _{W 1} of the standing wave W is set to be positioned on the treatment surface 110 (step S1).
Incidentally, the distance L is detected measurement values by the distance detection means 53 based on the (information), the control unit 70, the size sections W ₁ of the standing wave W is positioned at the treatment surface 110 (operator Is set by operating the moving means 5 until it reaches a magnitude determined from the vibration frequency of the vibrator 9 input to the operation unit 75.

[2] Next, by the operation of the first circuit 8, the high-frequency power source 82 is operated and the switch 83 is closed. Further, the valve 15 is opened by the operation of the gas supply means 11, and the gas is sent from the gas cylinder 13 while adjusting the flow rate of the gas with the regulator 14.
As a result, the gas delivered from the gas cylinder 13 flows through the gas supply pipe 12, is divided into each branch pipe 121, and is ejected (supplied) between the dielectric layer 3 and the workpiece 100 from each nozzle 16. On the other hand, by the operation of the high frequency power source 82, a high frequency voltage is applied between the application electrode 2 and the pallet 4, and an electric field is generated between them. At this time, the voltage applied between the application electrode 2 and the pallet 4 is set to a magnitude that provides a plasma concentration that improves the processing efficiency on the processing target surface 110.

Here, the gas flowing between the application electrode 2 and the workpiece 100 is activated by discharge between the portion where the electric field is generated, that is, between the surface to be processed 110 and the opposing surface 30, and plasma is generated. To do. Thereby, the plasma processing is performed on the processing target surface 110 of the workpiece 100 (step S2).
At this time, the AC power source 102 and the frequency adjusting means 74 are operated, and the switch 103 is closed. The frequency adjusting unit 74 is controlled by the control unit 70 so that the vibrator 9 vibrates at the magnitude of the frequency input to the operation unit 75.

As a result, the vibrator 9 vibrates at a predetermined frequency, and a standing wave W in which the position of the node W ₁ is located on the processing surface 110 is generated between the processing surface 110 and the facing surface 30. As a result, the active species 20 generated in the plasma receives a force due to the acoustic radiation pressure (standing wave) and moves to the vicinity of the surface 110 to be processed of the workpiece 100 (position of the node W ₁ of the standing wave W). , Captured at this position. Therefore, the active species 20 stays in the vicinity of the surface 110 to be processed of the workpiece 100 for a long time and reacts sufficiently with the surface 110 to be processed. As a result, good plasma processing is efficiently performed on the surface 110 to be processed.

[3] Next, due to the progress of the plasma processing on the surface 110 to be processed, the temperature T and the thickness of the workpiece 100 on the surface 110 to be processed change, so that the node W of the standing wave W is changed. It is determined whether ₁ is moving from the surface 110 to be processed. That is, it is determined whether the position deviation from the treatment surface 110 of the section W ₁ of the standing wave W is generated (step S3).
In step S3, in a case where the movement from the treatment surface 110 of the section _{W 1} is not recognized ( "NO" in step S3), and returns to step S2, and continues the plasma treatment of the surface to be processed 110.

On the other hand, when the movement of the node W ₁ from the surface to be processed 110 is recognized in Step S3 (“YES” in Step S3), the power is set so that the plasma density on the surface to be processed 110 is kept constant. By operating the adjustment means 85, the magnitude of the voltage applied between the application electrode 2 and the pallet 4 is changed (step S4). In this way, the plasma processing on the processing target surface 110 is continued in a state where the plasma density on the processing target surface 110 is kept constant (step S5).

[4] Next, it is determined whether or not the thickness of the workpiece 100 on the processing surface 110 has changed to a target size as the processing of the processing surface 110 with plasma proceeds (step). S6).
In step S6, when the thickness of the workpiece 100 on the surface 110 to be processed has not changed to the target size (“NO” in step S6), the process returns to step S2 to continue the plasma processing on the surface 110 to be processed. To do.
On the other hand, in step S6, when the thickness of the workpiece 100 on the processing target surface 110 has changed to the target size (“YES” in step S6), the plasma processing is terminated and the present flow is terminated.

  In the gas supply means 11 having the configuration as described in the present embodiment, since the gas is ejected from the application electrode 2 side to the workpiece 100 side by the nozzle 16, the active species 20 generated in the plasma It rides on the gas flow and flows toward the work 100 side. For this reason, there is a concern that the active species 20 may diffuse to the edge side of the table 6 (workpiece 100) after hitting the surface 110 to be processed.

However, in this embodiment, the vibrator 9 is disposed on the lower surface 63 of the table 6, and the node W ₁ on the workpiece 100 side is positioned between the surface to be processed 110 and the facing surface 30. Since the standing wave W is configured to be generated, the active species 20 is captured in the vicinity of the surface 110 to be processed. Therefore, the active species 20 stays in the vicinity of the surface to be processed 110 of the workpiece 100 for a long time, and good plasma processing can be efficiently performed on the surface to be processed 110 of the workpiece 100.
That is, the present invention is particularly effective when applied to the gas supply means 11 having such a configuration.

Second Embodiment
FIG. 5 is a cross-sectional view (including a partial block diagram) schematically showing a second embodiment of the plasma processing apparatus of the present invention. Hereinafter, the second embodiment shown in FIG. 5 will be described, but the description will focus on the points different from the first embodiment, and the description of the same matters will be omitted.
The second embodiment shown in FIG. 5 is the same as the first embodiment except for the configuration of the gas supply means 11. That is, the gas supply means 11 does not have the nozzle 16 and the branch pipe 121, and the gas supply pipe 12 is installed so that the downstream end side thereof is located between the application electrode 2 and the workpiece 100.

In the gas supply means 11 having such a configuration, a predetermined gas is sent out from the gas cylinder 13 with the valve 15 opened, and this gas flows through the gas supply pipe 12 and the flow rate is adjusted by the regulator 14. Thereafter, the gas is introduced (supplied) between the application electrode 2 (dielectric layer 3) and the workpiece 100 from a gas outlet formed at the downstream end of the gas supply pipe 12.
Also in the second embodiment, the same operation and effect as the first embodiment can be obtained.

<Third Embodiment>
FIG. 6 is a cross-sectional view (including a partial block diagram) schematically showing a third embodiment of the plasma processing apparatus of the present invention. Hereinafter, the third embodiment shown in FIG. 6 will be described, but the description will focus on the points different from the first embodiment, and the description of the same matters will be omitted.
The third embodiment shown in FIG. 6 differs in the configuration of the application electrode 2 and the nozzle 16 except that the vibrator 9 is provided on the application electrode 2 side instead of being provided on the workpiece 100 side. The main configuration is substantially the same as that of the first embodiment.

In the plasma processing apparatus 1 of the present embodiment, as shown in FIG. 6, the lower surface 22 of the application electrode 2 is smaller than the surface to be processed 110, and the nozzle 16 includes the application electrode 2 and a dielectric. One is formed so as to penetrate the layer 3, and the vibrator 9 is formed so as to cover a part of the outer peripheral surface of the application electrode 2 via an insulator 94.
The distance detecting means 53 is provided on the facing surface 30 side of the dielectric layer 3 instead of being provided on the upper surface 42 side of the pallet 4. Thereby, even when the lower surface 22 of the application electrode 2 is smaller than the surface to be processed 110 as in the present embodiment, the separation distance between the surface to be processed 110 and the facing surface 30 is ensured. Can be detected.

In the plasma processing apparatus 1 having such a configuration, when the application electrode 2 or the workpiece 100 is scanned, the processing target 110 of the workpiece 100 is subjected to plasma processing while changing the positional relationship with each other.
Further, when scanning the application electrode 2 or the workpiece 100, the position of the sound pressure detecting means 73 is changed so as to be positioned between the application electrode 2 and the workpiece 100 as shown in FIG.

Also in the third embodiment, the same operation and effect as in the first embodiment can be obtained.
In the plasma processing apparatus 1 according to the present embodiment, the plasma generation region is smaller than that in the first embodiment. Therefore, since the region where the standing wave is generated is also reduced, the standing wave can be generated relatively easily and stably between the surface to be processed 110 and the facing surface 30 by the vibrator 9.

As described above, the plasma processing apparatus of the present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these embodiments, and the configuration of each unit is an arbitrary configuration having the same function. Can be replaced. Moreover, other arbitrary structures and processes may be added.
Further, the present invention may be a combination of any two or more configurations (features) of the above embodiments.

In the first and second embodiments, the positional relationship between the pallet 4 and the application electrode 2 with respect to the longitudinal direction of the pallet 4 is fixed, but at least one of the table 6 and the application electrode 2 is used. Further, a moving means that is movable in the longitudinal direction of the pallet 4 may be provided so that the pallet 4 and the application electrode 2 move relatively. Thereby, the workpiece | work 100 with a larger area can be efficiently plasma-processed.
Furthermore, a plurality of workpieces 100 in the form of small pieces may be placed on the pallet 4 for processing, and in this case, the plurality of workpieces 100 can be subjected to plasma processing collectively. As a result, it contributes to the improvement of productivity.

In each of the above embodiments, the case where the pallet 4 and the workpiece 100 are vibrated integrally and the case where the application electrode 2 is vibrated have been described. However, the present invention is not limited to such a case. 2 or at least one of the workpieces 100 may be vibrated. For example, the workpiece 100 may be vibrated alone, or all of the pallet 4, the application electrode 2, and the workpiece 100 are vibrated. It may be.
Furthermore, the voltage applied between the application electrode 2 and the pallet 4 is not limited to a high-frequency voltage, and may be a pulse wave or a microwave, for example.

  Note that, as in each of the above-described embodiments, the pallet 4 may not be provided with the function of the counter electrode, and an electrode serving as the counter electrode of the application electrode 2 may be separately provided. In this case, the counter electrode may be bonded to the lower surface of the pallet 4, and the vibrator 9 may be disposed on the lower surface of the counter electrode via an insulator. The vibrator may be disposed on the upper surface of the counter electrode via the insulator. 9 may be provided, and the upper surface of the vibrator 9 may be bonded to the lower surface of the pallet 4. In the former case, when the piezoelectric body 91 of the vibrator 9 expands and contracts, the insulator, the counter electrode, the pallet 4 and the work 100 arranged on the upper side vibrate, and a sound wave (standing wave) is generated above the work 100. appear. On the other hand, in the latter case, when the piezoelectric body 91 of the vibrator 9 expands and contracts, the pallet 4 and the workpiece 100 arranged on the upper side vibrate, and a sound wave is generated above the workpiece 100.

It is sectional drawing which shows typically 1st Embodiment of the plasma processing apparatus of this invention. It is a schematic diagram which shows the state in which the standing wave has generate | occur | produced between the application electrode with which the plasma processing apparatus shown in FIG. It is a block diagram which shows the circuit structure of the plasma processing apparatus shown in FIG. It is a flowchart of the processing operation with respect to the to-be-processed surface of the workpiece | work by the plasma processing apparatus shown in FIG. It is sectional drawing which shows typically 2nd Embodiment of the plasma processing apparatus of this invention. It is sectional drawing which shows typically 3rd Embodiment of the plasma processing apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Plasma processing apparatus 2 ... Applied electrode 22 ... Lower surface 20 ... Active species 3 ... Dielectric layer 30 ... Opposite surface 4 ... Pallet 41 ... Recess 42 ... Upper surface 5 ... Moving means 50 ... ... Cylinder 51 ... Cylinder body 52 ... Piston 53 ... Distance detection means 6 ... Table 61 ... Recess 62 ... Upper surface 63 ... Lower surface 70 ... Control means 71 ... Temperature detection means 72 ... Thickness detection Means 73 …… Sound thickness detection means 74 …… Frequency adjustment means 75 …… Operation section 8 …… First circuit 81 …… Conductor 82 …… High frequency power supply 83 …… Switch 84 …… Matching box 85 …… Power adjustment means DESCRIPTION OF SYMBOLS 9 ... Vibrator 91 ... Piezoelectric body 92, 93 ... Electrode 94 ... Insulator 10 ... 2nd circuit 101 ... Conductor 102 ... AC power supply 103 ... Switch 1 DESCRIPTION OF SYMBOLS 1 ... Gas supply means 12 ... Gas supply pipe 121 ... Branch pipe 13 ... Gas cylinder 14 ... Regulator 15 ... Valve 16 ... Nozzle 100 ... Workpiece 110 ... Surface to be processed

Claims (11)

A first electrode and a second electrode arranged to face each other across the workpiece;
Gas supply means for supplying a gas for generating plasma on the surface to be processed of the workpiece;
A power supply unit that applies a voltage between the first electrode and the second electrode so as to activate the gas supplied by the gas supply means to generate plasma;
A plasma processing apparatus for processing the surface to be processed with plasma generated by the operation of the gas supply means and the power supply unit,
A vibrator that generates a vibration wave in a plasma generation region where the plasma is generated by vibrating at least one of the first electrode, the second electrode, and the workpiece;
Power adjusting means for adjusting the magnitude of the voltage applied between the first electrode and the second electrode;
Control means for controlling the operation of the power adjustment means,
The plasma processing apparatus, wherein the control means operates the power adjustment means to adjust the magnitude of the voltage applied between the first electrode and the second electrode. Distance detecting means for detecting a distance between a surface to be processed of the workpiece and the surface of the first electrode or the second electrode facing the surface to be processed;
Moving means for defining a separation distance between the surface to be processed of the workpiece and the facing surface by moving the first electrode or the second electrode;
Prior to processing the surface to be processed of the workpiece, based on the information from the distance detection means, the control means operates the moving means to adjust the separation distance, whereby the separation distance is set. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is set to a magnitude at which a standing wave is generated between a surface to be processed of the workpiece and the facing surface.   The plasma processing apparatus according to claim 2, wherein the standing wave is generated between the surface to be processed of the workpiece and the facing surface in a direction substantially orthogonal to the surface to be processed of the workpiece.   The plasma processing apparatus according to claim 2, wherein the control unit controls the node of the standing wave to be positioned on a surface to be processed of the workpiece. Sound pressure detecting means for detecting a change in sound pressure between the surface to be processed of the workpiece and the facing surface during processing of the surface to be processed of the workpiece by the plasma;
The control means obtains the magnitude of positional deviation of the node of the standing wave from the processing surface based on the amount of change in the sound pressure detected by the sound pressure detection means,
The plasma processing apparatus according to claim 4, wherein the plasma density on the surface to be processed is maintained constant by operating the power adjusting unit according to the magnitude of the positional deviation. Temperature detecting means for detecting a temperature change in a region where the plasma is generated during processing of the workpiece surface by the plasma, and a thickness detecting means for detecting a change in the thickness of the work by the plasma And
The control unit is configured to detect a positional deviation of the node of the standing wave from the surface to be processed based on the temperature change and the thickness change detected by the temperature detection unit and the thickness detection unit, respectively. For the size of
The plasma processing apparatus according to claim 4, wherein the plasma density on the surface to be processed is kept constant by operating the power adjusting unit according to the magnitude of the positional deviation. The plasma processing apparatus according to claim 2, wherein the standing wave has a frequency set in a range of 1 × 10 ⁵ to 1 × 10 ⁸ Hz.   8. The plasma processing apparatus according to claim 2, wherein a standing wave is generated between the surface to be processed and the facing surface after generating plasma between the surface to be processed and the facing surface. . The workpiece is placed on the first electrode;
The plasma processing apparatus according to claim 1, wherein the first electrode and the workpiece are vibrated integrally by the vibrator. The workpiece is placed on the first electrode;
The plasma processing apparatus according to claim 1, wherein the second electrode is vibrated by the vibrator.   The plasma according to claim 9 or 10, wherein the gas supply means includes at least one nozzle that is provided through the second electrode and ejects the gas between the second electrode and the workpiece. Processing equipment.

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