JP2007042503A - Atmospheric pressure plasma treatment device and atmospheric pressure plasma treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an atmospheric pressure plasma treatment device in which a cost increase and a complexity of device are avoided and which has no treatment unevenness and has a high speed treatment, and a method of an atmospheric pressure plasma treatment. <P>SOLUTION: An atmospheric pressure plasma treatment device is provided with an electrode unit 1 composed of a voltage impressing electrode 2, a grounding electrode 3 placed facing the above and an insulating part 4 placed between the above electrodes, a workpiece transfer unit 7 which transfers a workpiece 8, a reactive gas supplying means which supplies a reactive gas between the insulating part 4 and the workpiece 8 facing the same and a power source 9 which impresses a voltage. A strong electric field is created and a plasma is generated between the above electrodes 2, 3 and a required treatment is conducted on the workpiece 8. The device is provided also with a projected part 13 with which a strong electric field is created in a specific area of a part of the insulating part 4 facing a voltage impressed electrode and a part facing a grounding electrode and which makes a direction of the strong electric field inclined against a transfer direction 15 of the workpiece 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an atmospheric pressure plasma processing apparatus and an atmospheric pressure plasma processing method. More specifically, the present invention relates to an activity generated in a plasma by generating an electric field by generating an electric field under the atmospheric pressure of a reactive gas or in the vicinity thereof. The present invention relates to an atmospheric pressure plasma processing apparatus and an atmospheric pressure plasma processing method for performing processing such as thin film formation, processing, and surface treatment on various objects to be processed, for example, a silicon substrate, using chemical reactions by seeds.

  In recent years, various atmospheric pressure plasma processing apparatuses and atmospheric pressure plasma processing methods of this type have been proposed. In particular, by performing the treatment at or near atmospheric pressure, it is not necessary to evacuate the inside of the reaction vessel to a high vacuum, and the apparatus configuration can be simplified, so that the manufacturing cost of the plasma processing apparatus can be greatly reduced. There is an advantage.

  The details of the atmospheric pressure plasma processing apparatus and the atmospheric pressure plasma processing method are disclosed in detail in, for example, Japanese Patent No. 3014111 (Patent Document 1). In the above publication, an atmospheric pressure plasma is generated between the electrodes by applying a voltage between the opposing electrodes, and an object to be processed is disposed in the atmospheric pressure plasma generated between the electrodes. . Such a processing method is referred to herein as a direct plasma method. In this direct plasma system, active species are generated very close to the surface of the object to be processed, and the active species can reach the surface of the object to be processed earlier than it is deactivated, so that high-speed processing is possible. . However, on the other hand, since the workpiece is directly exposed to an electric field for generating plasma, there is a problem that the workpiece is damaged when an arc-like discharge is generated between the electrodes.

  In contrast to the direct plasma method, for example, Japanese Patent No. 2537304 (Patent Document 2) discloses a method in which an electric field for generating plasma can be directly performed without contacting an object to be processed. ing. In the above publication, plasma is generated by applying a voltage between opposed electrodes, and an active species generated by the plasma is directed toward an object to be processed disposed outside a discharge region by a gas flow flowing between the electrodes. A desired process is performed by ejecting. Such a processing method is referred to herein as a remote plasma method. In this remote plasma system, the plasma generation position is located away from the object to be processed, and the active species generated in the plasma are transported to the surface of the object to be processed by the gas flow between the electrodes. . From this, the direct plasma system has the advantage that damage to the object to be processed by plasma is not great. However, on the other hand, since many active species are deactivated before reaching the object to be processed from the plasma generation position, the processing speed is slow, and in order to secure a desired processing speed, the number of electrode pairs is increased. I have to. For this reason, when the number of sets of electrodes is increased in order to form a gas flow path between the opposed electrodes, the apparatus cost can be increased and the reaction gas once used for the discharge can be used again for the discharge. Since it is difficult, there are problems such as low utilization efficiency of the reaction gas.

  Japanese Laid-Open Patent Publication No. 2000-306848 (Patent Document 3) discloses a method for realizing processing that has a high processing speed and does not damage an object to be processed with respect to these atmospheric pressure plasma processing.

FIG. 8 is a schematic structural explanatory view showing the schematic structure of the atmospheric pressure plasma processing apparatus disclosed in this publication in a cross-sectional view.
In FIG. 8, in the atmospheric pressure plasma processing apparatus, a voltage application electrode 103 and a ground electrode 104 are installed with an insulator 105 interposed therebetween to form an electrode unit H1, and a sample 108 is installed facing the electrode unit H1. Thus, a gas flow path is formed between the insulator 105 and the sample 108.
In addition, 101 is a high pressure reactive gas supply port, 102 is a reactive gas exhaust port, 106 is a power transmission path open end, 107 is a sample stage, 109 is atmospheric pressure plasma, and 110 is a reactive gas flow direction.

The reactive gas is supplied to the gas flow path, and the atmospheric pressure plasma 109 is generated by applying a voltage between the voltage application electrode 103 and the ground electrode 104, and the active species generated in the atmospheric pressure plasma 109 are generated. The process is performed by Such a processing method is referred to herein as a semi-remote plasma method. According to this semi-remote plasma method, the electric field for generating plasma is not directly exposed to the object to be processed, as in the case of the remote plasma method. Less is. Further, according to the semi-remote plasma method, discharge occurs in the gas flow path between the insulator 105 and the sample 108, and therefore the distance between the plasma and the object to be processed is shorter than that in the remote plasma method. Since there are many active species that reach the substrate without being activated, the processing speed is increased, and in order to further improve the processing speed, a structure in which a plurality of electrodes are arranged and the number of plasmas is increased, the gas flow direction is increased. Since the reaction gas used for plasma discharge at the upstream position can also be used for plasma discharge at the downstream position, the reaction gas utilization efficiency is very high, and the gas cost can be reduced compared to the remote plasma method. Yes.
With this background, research and development on the semi-remote plasma method is ongoing.
Japanese Patent No. 3014111 Japanese Patent No. 2537304 JP 2000-306848 A

On the other hand, regardless of the method described above, plasma at atmospheric pressure or in the vicinity of pressure is likely to be non-uniform. In atmospheric pressure plasma processing using such atmospheric pressure plasma, processing that reflects the plasma distribution is performed. There is a problem that characteristic distribution occurs.
Here, how the discharge develops will be described. First, the applied voltage is increased, and plasma in a state called glow discharge is generated when the electric field intensity exceeds a certain threshold value. This threshold value varies depending on conditions such as the structure of the electrode and the processing gas used. Although this glow discharge is a spatially uniform discharge, since the plasma density is low, the active species density is also low, and therefore the processing speed is slow. Therefore, if the applied voltage is further increased, the plasma can be shaded in the longitudinal direction (long direction) of the electrode unit. If the applied voltage is further increased from that state, a discharge portion with very high luminance is generated in a very small part of the discharge region. Here, this is called filament discharge.

  In the filament discharge, only a part of the discharge region emits a strong light. When the applied voltage is further increased, the filament discharge is generated in the longitudinal direction of the electrode unit at a substantially equal pitch depending on the gas, electrode shape, and applied power. Since such a filament discharge region has a higher plasma density than other glow discharge regions, the active species density is also very high. Therefore, if processing can be performed in the filament discharge region, a large processing speed can be obtained.

  However, as described above, in the case where filament discharges that are arranged at substantially equal pitches in the longitudinal direction of some electrode units are generated, the region where the filament discharge is generated is locally plasma density as described above. Becomes higher. For this reason, the processing speed of the part located immediately under the filament discharge in the workpiece is high, and the processing speed of the part where the filament discharge is not generated is low. As a result, striped processing characteristic distribution perpendicular to the longitudinal direction of the electrode unit is generated by the transport of the workpiece due to the influence of filament discharge arranged in the longitudinal direction of the electrode unit on the workpiece. Become. Furthermore, since it is impossible to control the filament discharge to a desired position, it is difficult to control the processing characteristic distribution that appears due to the filament discharge. Further, when the applied voltage is further increased, the width of the filament discharge can be expanded. Therefore, it is desirable because the processing speed increases as a whole and the uniformity also increases. However, if the applied voltage is increased too much, an arc-like discharge occurs between the electrode and the object to be processed, and the object to be processed is damaged.

Therefore, in the current situation, treatment using filament discharge is avoided, filament discharge is suppressed, and treatment is often performed by glow discharge. However, in the case of processing by glow discharge, the processing speed is slow as described above. Therefore, an increase in the number of electrodes and an increase in applied voltage compensate for a low processing speed, resulting in an increase in apparatus cost and an increase in apparatus complexity. In particular, this problem becomes more prominent if the workpiece becomes larger.
The present invention has been made in view of the above problems, and its purpose is to generate a locally strong electric field, particularly a filament discharge, at a specific position between the voltage application electrode and the ground electrode, and to generate the plasma. By applying it to processing, it is to provide a plasma processing method having no processing characteristic distribution and high processing speed while avoiding cost increase and complexity of the apparatus.

  The present invention relates to at least one electrode unit comprising a voltage application electrode, a ground electrode disposed opposite to the voltage application electrode, and an insulator disposed between the two electrodes, and an insulator of the electrode unit A workpiece conveying means for conveying the workpiece to be opposed to the substrate, a reaction gas supply means for supplying a reaction gas between the insulator and the workpiece to be opposed thereto, and a voltage application for applying a voltage to the electrode unit And generating a plasma by locally forming a strong electric field between the electrodes under the atmospheric pressure of the reaction gas or a pressure in the vicinity thereof, and irradiating the object with the active species generated by the plasma In an atmospheric pressure plasma processing apparatus for performing a desired process on an object to be processed,

  At least the insulator causes the strong electric field to be formed at a specific position on the voltage application electrode side portion and / or the ground electrode side portion, thereby tilting the direction of the strong electric field with respect to the conveyance direction of the workpiece. Provided is an atmospheric pressure plasma processing apparatus comprising one protrusion.

  According to another aspect of the present invention, by applying a voltage to a voltage application electrode and a ground electrode that are disposed to face each other with an insulator interposed therebetween, an atmospheric pressure or a pressure in the vicinity thereof is applied between the two electrodes. In an atmospheric pressure plasma processing method, a plasma is generated by forming an electric field in the presence of a reactive gas, and an active species generated by the plasma is irradiated to the object to be transported to perform a desired process on the object to be processed. ,

  A strong electric field is locally formed at a specific position between the voltage application electrode and the ground electrode by the protrusion formed on the voltage application electrode side portion and / or the ground electrode side portion of the insulator, and this strong electric field It is possible to provide an atmospheric pressure plasma processing method characterized in that the direction is inclined with respect to the conveyance direction of the workpiece.

  According to the present invention, a locally strong electric field is formed at a specific position between the voltage application electrode and the ground electrode on the voltage application electrode side portion and / or the ground electrode side portion of the insulator facing the object to be processed. And a projection that inclines the direction of the strong electric field (direction of electric lines of force) with respect to the conveyance direction of the object to be processed, so that the processing speed of the object to be processed by the plasma generated by the strong electric field is high. The processing range, especially the processing range where the processing speed of the object to be processed by filament discharge is very fast, extends in the longitudinal direction of the electrode unit, and the processing characteristic distribution is small and the processing speed distribution is small without increasing the cost and complication of the apparatus. Enable processing.

In the atmospheric pressure plasma processing apparatus according to the present invention, the insulator of the electrode unit causes a strong electric field to be formed at a specific position on the voltage application electrode side portion and / or the ground electrode side portion. At least one protrusion that inclines the substrate with respect to the conveying direction of the workpiece.
Here, as the protrusion, specifically, a prismatic protrusion (the angle of the tip is preferably 20 to 120 degrees, more preferably 40 to 90 degrees), a cylindrical protrusion, or a hemispherical protrusion. It is mentioned as preferable.

When these protrusions are provided in pairs on the voltage application electrode side portion and the ground electrode side portion of the insulator, the position where a strong electric field is generated is specified by biasing one protrusion sideways. (The tip portion of the protrusion serves as the discharge end of the electric field), and the direction of the strong electric field (direction of the electric lines of force) can be inclined with respect to the opposing direction of both electrode units, thereby both electrode units. Can be arranged perpendicular to the direction of conveyance of the workpiece.
On the other hand, when the protrusion is provided on either the voltage application electrode side portion or the ground electrode side portion of the insulator facing the object to be processed, the position where the strong electric field is generated can be specified. Is normally the same as the opposing direction of both electrode units. Therefore, the longitudinal direction of both electrode units is not relatively perpendicular to the conveying direction of the workpiece, but is perpendicular to the vertical direction. It is preferable to incline.

Here, the degree to which the direction of the strong electric field is inclined relative to the conveyance direction of the workpiece (angle: θ, see FIG. 3) is not particularly limited, but 0 ° <θ ≦ 90 °, preferably 20 ° ≦ θ ≦ 60 °.
Further, the insulator includes a plurality of sets of protrusions facing the voltage application electrode side portion and the ground electrode side portion, and the electrode unit longitudinal direction distance between the tips of the protrusions facing each set is X, and the electrode unit The distance between the tips of adjacent projections in the longitudinal direction is Y, the length of each projection in the direction perpendicular to the longitudinal direction of the electrode unit is Z, the lower end of the voltage application electrode side portion of the insulator and the lower end of the ground electrode side portion If the distance between and is W,
Y> 2X, WZ> [(W-2Z) ² + X ² ] ^1/2
It is preferable that each of the protrusions is arranged at equal intervals in the longitudinal direction of the electrode unit.

In the present invention, plasma generated by a strong electric field is preferably plasma by filament discharge.
In the present invention, a plurality of electrode units are provided so as to overlap each other, and the insulator of each electrode unit includes protrusions on the voltage application electrode side and the ground electrode side, and these protrusions are electrodes of the object to be processed. If all the positions in the longitudinal direction of the unit are distributed and arranged so that the treatment by the filament discharge is performed the same number of times, the uniformity of the treatment on the workpiece can be maintained, and a high-quality treatment can be obtained. desirable.
Hereinafter, Embodiment 1 of the atmospheric pressure plasma processing apparatus of the present invention will be specifically described with reference to the drawings.

[Embodiment 1]
FIG. 1 is a schematic structural explanatory view showing a schematic structure of a first embodiment of an atmospheric pressure plasma processing apparatus according to the present invention in a cross-sectional view, and FIG. 2 is a schematic structure of an insulator in an electrode unit of the first embodiment. It is a schematic structure explanatory drawing which shows this using a bottom view and a cross-sectional view.
In FIG. 1, the atmospheric pressure plasma processing apparatus according to the first embodiment includes an electrode unit 1 including a voltage application electrode 2, a ground electrode 3, and an insulator 4, a transport apparatus 7 for transporting an object 8 to be processed, The gas flow path 6 formed between the electrode unit 1 and the transfer device 7 and a power source 9 are mainly configured.

  The voltage application electrode 2 is connected to the power source 9, and the ground electrode 3 is grounded. An insulator 4 is sandwiched between the voltage application electrode 2 and the ground electrode 3. On the surface of the insulator 4 on the side of the gas flow path 6, a recess that becomes a seed plasma generation region 11 and a plasma restriction region 12 is provided between the opposing surfaces of the voltage application electrode 2 and the ground electrode 3, or opposite to each other. It is provided below the plane. The electrode unit 1, the transfer device 7, and the gas flow path 6 are sufficient for processing the workpiece 8 in the electrode unit longitudinal direction 10 (orientation perpendicular to the paper surface, see FIG. 2). It is continuous and the end may take any form.

The material for the voltage application electrode 2 and the ground electrode 3 is appropriately selected from metal materials, and for example, Al, Cu, brass or the like can be used. As the material of the insulator 4, for example, Al ₂ O ₃ , MgO, TiO ₂ , AlN or the like can be used. If necessary, a device for controlling impedance so as to form a resonance circuit including electrodes and plasma may be inserted into the power source 9 in order to efficiently apply a voltage to the voltage application electrode 2.
Further, by introducing the reaction gas into the gas flow path 6, the reaction gas flows into the gas flow path 6 between the electrode unit 1 and the transfer device 7. The reaction gas preferably contains a rare gas such as He, Ne, or Ar so that the discharge can be easily maintained, and an additive gas is added to the rare gas according to a desired treatment. As the additive gas, for example, an oxidizing gas such as O ₂ , air, water vapor, or the like may be used if processing such as cleaning of the organic matter on the surface of the object to be processed, removal of the resist, or processing of the organic material film is performed. If etching is performed on a silicon material such as Si, SiO ₂ , or SiN, a halogen gas such as CF ₄ , CHF ₃ , or SF ₆ may be used.

  When the reaction gas is introduced into the gas flow path 6 and a voltage is applied between the voltage application electrode 2 and the ground electrode 3, the strongest electric field is generated in the seed plasma generation region 11 surrounded by the insulator 4. Is formed. Furthermore, when the applied voltage is increased and the electric field intensity of the seed plasma generation region 11 exceeds a certain threshold value, plasma is generated in the vicinity of the seed plasma generation region 11. Here, the plasma generated in the seed plasma generation region 11 is referred to as seed plasma. By further increasing the applied voltage from the state where the seed plasma is generated, the plasma expands in the plasma limited region 12. Here, the plasma restriction region 12 is a region surrounded by the insulator 4 on the voltage application electrode 2 side and the insulator 4 on the ground electrode 3 side in the gas flow path 6. A portion excluding the plasma generation region 11 is shown.

  When the applied voltage is further increased, a discharge called a filament discharge having the protrusion 13 as a discharge end appears in a part of the discharge region. By further increasing the applied voltage from there, the filament discharge having the protrusion 13 as a discharge end is periodically arranged in the longitudinal direction of the electrode unit (equally arranged horizontally at the electrode unit 1).

  When the plasma is generated and the additive gas is added to the plasma, the additive gas is excited to generate active species. The larger the voltage applied at this time, the better the processing speed can be improved. However, if the voltage is too large, the electric field between the voltage application electrode 2 and the object 8 to be processed generates a plasma. Therefore, a discharge may occur between the voltage application electrode 2 and the workpiece 8 and the workpiece 8 may be damaged significantly. The value of the applied voltage is the kind of the reaction gas, the composition of the reaction gas, the flow rate of the reaction gas, the distance L between the electrode unit 1 and the workpiece 8, the voltage application electrode 2 and the ground electrode 3 The distance D is appropriately determined according to the required processing capacity and the like.

Further, it is desirable that the processing capability is improved as the distance between the electrode unit 1 and the workpiece 8 is reduced. However, if this is too small, a discharge occurs between the voltage application electrode 2 and the workpiece 8. The value of the distance between the electrode unit 1 and the object to be processed 8 is the electric field strength of the plasma limiting region 12 determined by the electrode structure, the applied voltage, the dimensions of the electrode unit 1, the material of the object to be processed 8, etc. It is changed appropriately according to.
Here, in the first embodiment, the principle of improving the processing capability while avoiding the complexity and cost increase of the apparatus will be described.

As shown in FIG. 2, by providing the protrusions 13 on the voltage application electrode 2 side and the ground electrode 3 side, lines of electric force having the respective protrusions 13 as termination points are formed.
FIG. 3 is a main part structure explanatory view showing the structure of the main part of the insulator in the electrode unit of the first embodiment, and FIG. 4 is a result of performing electromagnetic field analysis on the insulator structure of the first embodiment. FIG. 5 is a detailed basic structure explanatory view for explaining a detailed basic structure of an insulator in the electrode unit according to the first embodiment.

  In the first embodiment, as shown in FIG. 3, assuming that the angle between the straight line connecting the apexes of the protrusions 13 on the opposing electrodes and the electrode unit longitudinal direction 10 is θ, 0 ° <θ <180 It is arranged so as to satisfy ° and θ ≠ 90 °. As a result, the direction of main lines of electric force changes from the conventional direction satisfying θ = 90 ° to the direction satisfying 0 ° <θ <180 ° and θ ≠ 90 °. Therefore, the filament discharge constrained by the main electric lines of force also satisfies 0 ° <θ <180 ° and θ ≠ 90 ° as shown by the arrow 14 in FIG. 13 to connect the protrusion 13 on the ground electrode 3 side.

In the conventional filament discharge, unless it is provided with a mechanism that intentionally creates an electric field distribution, it is unknown where the electrode is generated and it is impossible to control it. In the invention, since the main electric lines of force are generated between the protrusions 13 on the voltage application electrode 2 side and the ground electrode 3 side, the filament discharge may be fixed and generated at a specific position. it can.
Further, in the conventional processing by filament discharge, the processing characteristic distribution is noticeable in a region where the processing speed is low due to glow discharge and a region where the processing speed is high due to filament discharge. In this embodiment, processing is performed with filament discharge having an angle satisfying 0 ° <θ <180 ° and θ ≠ 90 °.

By carrying the object to be processed so as not to be parallel to the filament discharge direction, the treatment range by filament discharge in the direction of the electrode unit longitudinal direction 10 is expanded, and the treatment characteristic distribution is made more uniform than before. Processing is possible. Further, by arranging two or more sets of the voltage application electrode 2 and the ground electrode 3 and setting the number of plasmas to two or more, the entire surface can be uniformly processed in a direction parallel to the electrode unit 1.
Here, FIG. 4 shows the result of examining how the electric field strength distribution changes in the electromagnetic field simulation when the electrode insulator having the shape as in the present invention is used.

  The analysis was performed using the electrode unit in the first embodiment. As a result, a uniform electric field is generated substantially along the electrode insulator in the related art, but by providing the protrusion 13, the electric field contrast is obtained in the longitudinal direction 10 of the electrode unit, and the voltage applying electrode 2 It can be seen that the linear electric field connecting the protrusion 13 on the side and the protrusion 13 on the ground electrode 3 side is strong. That is, the filament discharge generated so as to be restrained by the main electric lines of force of the electric field is 0 ° <θ <180 ° and θ ≠ 90 ° with respect to the longitudinal direction of the electrode unit 1 by providing the protrusion 13. It occurs at a specific position with an angle satisfying.

Further, as shown in FIG. 5, the protrusion 13 has a distance X parallel to the electrode unit longitudinal direction 10 of the protrusion 13 on the opposite electrode, and a distance Y of the adjacent protrusion 13 on the same electrode. When the height of the protrusion 13 is Z and the width of the plasma restriction region 12 is W,
Y> 2X, WZ> {(W-2Z) ² + X ² } ^1/2
It is desirable to satisfy the above relationship and to be arranged at equal intervals in the longitudinal direction of the electrode unit.

When Y = 2X, when viewed from the protrusion 13 on the voltage application electrode 2 side, the two adjacent protrusions 13 on the ground electrode 3 side are equidistant, so that the filament discharge position can be controlled reliably. This is because the contrast of the electric field cannot be obtained. Further, if WZ <{(W−2Z) ² + X ² } ^1/2 , the distance between the protruding portions 13 and the portions without the protruding portions 13 is shorter than the protruding portions 13. This is because the electric field does not have an angle with respect to the workpiece conveyance direction 15 and becomes an electric field perpendicular to the electrode unit longitudinal direction 10 as usual. The actual dimensions as shown in FIG. 5 may be appropriately changed according to various conditions such as gas composition, power supply frequency, applied voltage, and input power.

According to the present invention, processing that is more uniform than in the prior art is possible, and further, processing by filament discharge is possible, so both power efficiency and processing speed are improved. As a result, the apparatus cost and the power cost are increased. Complexity can be avoided.
Here, each dimension in FIG. 5 was set to X = 1 mm, Y = 4 mm, Z = 2 mm, and W = 6 mm, and the etching process was performed. At this time, sin θ = 2/5 ^1/2 (θ: about 63.4 degrees). The gas used is He1SLM, CF ₄ 3%, O ₂ 1%. The applied voltage was 4.8 kV. The power supply is a 13.56 MHz high frequency power supply. Moreover, conveyance of the to-be-processed object was performed perpendicularly with respect to the electrode unit longitudinal direction. In the conventional filament discharge process, a process with a variation of about 70 nm ± 40% can be obtained. In the processing in the first embodiment, it was possible to obtain a more uniform processing than the conventional example of about 70 nm ± 20%.
FIG. 6 is an explanatory view showing another structural example of an insulator in the electrode unit of the atmospheric pressure plasma processing apparatus according to the present invention.

  In the first embodiment, the shape of the protrusion as shown in FIG. 2 is used. However, the same effect can be obtained with the shape of the protrusion 13 as shown in FIG. FIG. 6-a shows the projection 13 changed to a cylindrical projection 13 to eliminate the edge, and FIG. 6-b shows a hemispherical projection 13 added. If there is an edge, the electric field is excessively concentrated and the insulator may be destroyed. When a large voltage is applied, the insulator can be prevented from being damaged by making the shape without an edge. However, since the effect of concentrating the electric field strength is weakened, it may be appropriately changed depending on the applied voltage and gas conditions.

  In the first embodiment, the structure as shown in FIG. 1 is described as the electrode unit. However, the structure is not limited to such a structure. For example, although the seed plasma generation region and the plasma restriction region have shapes as shown in FIG. 1, they may have any shape, and one set of voltage application electrode and ground electrode is arranged. Any number of groups can be arranged. Further, the gas flow path may have any shape as long as a uniform gas can be supplied to the discharge space. As the frequency of the power source, 13.56 MHz was used, but there is no particular limitation, and any frequency may be used. Furthermore, in the first embodiment, the case where the moving direction of the object to be processed and the gas flow direction are the same has been described. However, this may be any direction, and if it is not parallel to the filament discharge direction, the conveyance direction The uniformity can be increased by appropriately changing the angle.

[Embodiment 2]
FIG. 7 is an explanatory view showing still another structural example of the insulator as the second embodiment in the electrode unit of the atmospheric pressure plasma processing apparatus according to the present invention.
FIG. 7 shows an example in which N electrode units as shown in FIG. 1 are used. The second embodiment is characterized in that the voltage application electrode 2 and the ground electrode 3 are alternately arranged, and there are N plasma limiting regions formed between the voltage application electrode 2 and the ground electrode 3. In addition, the configurations of the power source 9 and the transfer device 7 are the same as those shown in FIG.

As shown in FIG. 7, there is a configuration of the electrode unit 1 in which N sets of the voltage application electrode 2 and the ground electrode 3 are possible. At this time, the distance X parallel to the electrode unit longitudinal direction 10 of the protruding portion 13 on the opposite electrode and the distance Y of the protruding portion 13 on the same electrode side have a relationship of Y = NX, By shifting the arrangement of the protrusions 13 by X in the longitudinal direction 10 of the electrode unit for each group, it is possible to perform a process in which any part of the workpiece 8 is always subjected to a single filament discharge process. Using the electrode unit having such a structure, the experiment was performed under the conditions of using gas He1SLM, CF ₄ 3%, O ₂ 1%, applied voltage 4.8 kV, and high frequency power supply frequency 13.56 MHz. As a result, a processing result of about 70 nm ± 5% could be obtained.

  In the second embodiment, the arrangement of the projections 13 in each group is as shown in FIG. 7, but when the workpiece is transported, any portion of the workpiece is treated by filament discharge. As long as the arrangement of the protrusions of each set is experienced the same number of times, the arrangement does not have to be as shown in the second embodiment, and the conditions are appropriately changed depending on the processing conditions. .

BRIEF DESCRIPTION OF THE DRAWINGS It is schematic structure explanatory drawing which shows schematic structure of Embodiment 1 of the atmospheric pressure plasma processing apparatus which concerns on this invention. It is a schematic structure explanatory drawing which shows the schematic structure of an insulator among the electrode units of Embodiment 1 shown in FIG. It is principal part structure explanatory drawing which shows the structure of the principal part of an insulator among the electrode units of this Embodiment 1. FIG. It is explanatory drawing with a photograph which shows an example of the result of having performed electromagnetic field analysis with the insulator structure of this Embodiment 1. FIG. It is a detailed basic structure explanatory drawing explaining the detailed basic structure of an insulator among the electrode units of this Embodiment 1. FIG. It is explanatory drawing which shows the other structural example of an insulator among the electrode units of the atmospheric pressure plasma processing apparatus which concerns on this invention. It is explanatory drawing which shows the further another structural example of an insulator among the electrode units of the atmospheric pressure plasma processing apparatus which concerns on this invention. It is schematic structure explanatory drawing which shows schematic structure of the atmospheric pressure plasma processing apparatus which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode unit 2 Voltage application electrode 3 Ground electrode 4 Insulator 5 The gas flow path side surface 6 of an insulator 6 Gas flow path 7 Processed object conveyance apparatus 8 Processed object 9 Power supply 10 Electrode unit longitudinal direction (In FIG. (Vertical orientation)
11 species plasma discharge region 12 plasma limiting region 13 protrusion 14 electric field direction 15 transport direction

Claims (10)

At least one electrode unit composed of a voltage application electrode, a ground electrode disposed opposite to the voltage application electrode, and an insulator disposed between the two electrodes, and the electrode unit to be opposed to the insulator A workpiece conveying means for conveying the workpiece, a reactive gas supply means for supplying a reactive gas between the insulator and the workpiece to be treated, and a voltage applying means for applying a voltage to the electrode unit. Then, a plasma is generated by forming a strong electric field locally between the two electrodes under the atmospheric pressure of the reaction gas or in the vicinity thereof, and the object to be processed is irradiated with active species generated by the plasma. In an atmospheric pressure plasma processing apparatus for performing a desired processing on a processing object,
At least the insulator causes the strong electric field to be formed at a specific position on the voltage application electrode side portion and / or the ground electrode side portion, thereby tilting the direction of the strong electric field with respect to the conveyance direction of the workpiece. An atmospheric pressure plasma processing apparatus comprising one protrusion.   The atmospheric pressure plasma processing apparatus according to claim 1, wherein the protrusion is a prismatic protrusion.   The atmospheric pressure plasma processing apparatus according to claim 1, wherein the protrusion is a cylindrical protrusion or a hemispherical protrusion. The insulator includes a plurality of sets of protrusions facing the voltage application electrode side portion and the ground electrode side portion, and X is the electrode unit longitudinal direction distance between the tips of the opposing protrusions of each set, and the electrode unit longitudinal direction The distance between the tips of adjacent projections is Y, the length of each projection in the direction perpendicular to the longitudinal direction of the electrode unit is Z, and the lower end of the voltage application electrode side portion and the lower end of the ground electrode side portion of the insulator If the distance between them is W,
Y> 2X, WZ> [(W-2Z) ² + X ² ] ^1/2
The atmospheric pressure plasma processing apparatus according to claim 1, wherein the protrusions are arranged at equal intervals in the longitudinal direction of the electrode unit.   The atmospheric pressure plasma processing apparatus according to any one of claims 1 to 4, wherein the plasma generated by the strong electric field is plasma by filament discharge.   A plurality of electrode units are stacked, and the insulator of each electrode unit has protrusions on the voltage application electrode side and the ground electrode side, and these protrusions are all in the longitudinal direction of the electrode unit of the object to be processed. The atmospheric pressure plasma processing apparatus according to claim 5, wherein the apparatus is distributed and arranged so that the processing by the filament discharge is performed the same number of times. By applying a voltage to a voltage application electrode and a ground electrode arranged opposite to each other through an insulator, an electric field is formed between the electrodes in the presence of a reaction gas at atmospheric pressure or a pressure near it, and plasma is generated. In an atmospheric pressure plasma processing method for performing a desired process on an object to be processed by irradiating the object to be processed with active species generated by this plasma,
A strong electric field is locally formed at a specific position between the voltage application electrode and the ground electrode by the protrusion formed on the voltage application electrode side portion and / or the ground electrode side portion of the insulator, and this strong electric field An atmospheric pressure plasma processing method, wherein a direction is inclined with respect to a conveyance direction of an object to be processed.   The atmospheric pressure plasma processing method according to claim 7, wherein the protrusion is a prismatic protrusion.   The atmospheric pressure plasma processing method according to claim 7, wherein the protrusion is a cylindrical protrusion or a hemispherical protrusion.   The atmospheric pressure plasma processing method according to any one of claims 7 to 9, wherein the plasma generated by the strong electric field is plasma by filament discharge.