JP2004111385A - Plasma treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the distortion of an electrode by Coulomb force, in a plasma treatment device composed by arranging a pair of long electrodes in parallel with each other. <P>SOLUTION: This plasma treatment device S1 is provided with an electrode holder 30 for supporting the pair of long electrodes 20. In the electrode holder 30, a plurality of pull bolts 35 (close distortion prevention means) are mounted in the lengthwise direction of the electrodes 20 by being separated from one another. The head part of each pull bolt 35 is hooked on a rigid plate 33 through a bolt holder 36, and the leg part thereof is screwed into the electrode 20. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a plasma processing apparatus, and in particular, has a pair of parallel long electrodes, and introduces a processing gas from between one longitudinal side edges of these electrodes to between opposite surfaces to generate plasma. This plasma is generated, and this plasma is blown out of the electrode from between the other long side edges and applied to the object to be processed, and surface treatment such as thin film formation, etching, surface modification, removal of organic contaminants, water repellency or hydrophilicity is performed. The present invention relates to a remote-type plasma processing apparatus for performing the following.

2. Description of the Related Art A remote-type plasma processing apparatus that performs a surface treatment by introducing a processing gas between a pair of electrodes and causing a glow discharge to blow a plasma flow to an object to be processed outside the electrodes is known (for example, see Patent Document 1). . A plasma processing apparatus using a parallel plate electrode in which two flat plates are arranged in parallel is also known (see Patent Document 2).

JP-A-11-251304 JP-A-7-85997

In a remote type plasma processing apparatus using long parallel plate electrodes, a plasma flow is blown out from between the long side edges of these electrodes, so that surface treatment for the length of the electrodes can be performed at a time. Speed can be improved. However, due to the Coulomb force caused by the applied electric field, the electrodes may be deformed and deformed such that the electrodes approach each other, for example, at an intermediate portion in the longitudinal direction. This phenomenon becomes more conspicuous as the electrode becomes longer, for example, 50 cm or more.

歪 Also, strain deformation can occur due to the difference in thermal expansion when the electrode is heated by the current. That is, usually, the internal temperature of the electrode is higher in the portion closer to the other electrode than in the portion closer to the back surface. A difference is generated in thermal expansion according to the temperature difference, which appears as distortion. Also, distortion may occur due to the difference in the coefficient of thermal expansion between the metal forming the electrode and the solid dielectric layer coated on the metal electrode by thermal spraying or the like.

Further, also in the electrode manufacturing process, the blast treatment when coating the solid dielectric layer on the surface of the electrode by thermal spraying or the like, the difference in the coefficient of thermal expansion between the electrode and the thermal spray material, and the surface other than the dielectric coating surface In some cases, distortion and deformation of the electrode may occur due to heat or the like when polishing is performed as a positioning reference surface.

変 形 If there is such a deformation, the plasma flow cannot be blown out uniformly along the longitudinal direction of the electrode, and the uniformity of the surface treatment is impaired.

In order to solve the above problems, the present invention arranges a pair of long electrodes in parallel, applies an electric field between the electrodes, and applies a processing gas to the first long side edge of the electrodes. In a plasma processing apparatus which is introduced between the opposing surfaces from between each other and blows out from between the second longitudinal side edges, a distortion preventing mechanism for preventing each electrode from being distorted in the arrangement direction is provided. I do.
Accordingly, it is possible to prevent the electrodes from being distorted due to the Coulomb force or the difference in thermal expansion when an electric field is applied, and to prevent the gap between the electrodes from becoming uneven. Therefore, the plasma flow can be uniformly blown out along the longitudinal direction of the electrode, and a uniform surface treatment can be performed.
Here, it is desirable that each electrode extends linearly.

It is preferable that the distortion prevention mechanism includes an approach distortion prevention unit that prevents each electrode from being distorted so as to approach the other electrode.
As a result, it is possible to reliably prevent the electrodes from being distorted so as to approach each other by Coulomb force.

It is preferable that a plurality of the approach strain prevention means are provided apart from each other in the longitudinal direction of the electrode.
Thereby, the distortion of the electrode can be more reliably prevented.

A rigid member is provided on the back of each electrode opposite to the other electrode, and the approach strain preventing means includes a bolt (head) whose head is hooked on the rigid member and whose leg is screwed into the electrode. (Screw member).
Thereby, the configuration of the approach distortion preventing means can be simplified. Further, the position where the strain prevention force works can be easily adjusted by the screwing amount of the bolt.

The strain prevention mechanism includes approach strain prevention means for preventing each electrode from being distorted so as to approach the other electrode, and separation strain prevention means for preventing each electrode from being distorted away from the other electrode. It is desirable.
Thereby, the distortion of the electrode can be more reliably prevented.

A plurality of approaching means for bringing each electrode closer to the other electrode side and a plurality of separating means for separating each electrode are provided apart from each other in the longitudinal direction of the electrode, and the approaching means prevents the separation of the electrodes by preventing the separation distortion. It is preferable that the separating means also serves as the approach distortion preventing means by preventing approach of the electrode.
This makes it possible to correct even if distortion occurs in the electrode manufacturing process or the like, and to adjust the distance between the electrodes to be uniform along the longitudinal direction. Therefore, the flow of the plasma can be reliably made uniform in the longitudinal direction, and the surface treatment can be performed uniformly. In addition, it is possible to make the gas flow easier by increasing the distance between the electrodes, or to facilitate the discharge by reducing the distance between the electrodes. Furthermore, the number of components can be reduced by the approaching means also serving as the separation strain preventing means and the separating means also serving as the approaching strain preventing means. The approaching means and the separating means constitute a "strain correction mechanism for each electrode" or a "spacing adjustment mechanism between the electrodes".

A rigid member is provided on the back of each electrode opposite to the other electrode, and the approaching means, that is, the separating strain preventing means is screwed into the rigid member and abutted against the rear surface of the electrode to fix the electrode. A pulling bolt including a pushing bolt (a pushing screw member), wherein the separating means, ie, the approach strain preventing means, has a head hooked on the rigid member and a leg screwed into the electrode to pull the electrode toward the rigid member. (Pull screw member).
Thereby, the structure of the approaching means and the separating means can be simplified. Further, by adjusting the screwing amount of these push-pull bolts, it is possible to easily correct the distortion of each electrode and adjust the interval between the electrodes. Further, the position at which the strain prevention force works can be easily adjusted by the screwing amount of these push-pull bolts.

The present invention also provides a pair of elongated electrodes arranged in parallel, applies an electric field between the electrodes, and causes the processing gas to flow from between the first longitudinal side edges of the electrodes to the facing surface. A plasma processing apparatus which is introduced between the second longitudinal side edges and blows out from between the second longitudinal side edges; a plurality of approaching means which are arranged apart from each other in the longitudinal direction of the electrode and bring each electrode closer to the other electrode side; And a separating means for separating each electrode from the other electrode.
Thus, even if a distortion occurs in the electrode manufacturing process or the like, the distortion can be corrected by a plurality of approaching means and a plurality of separating means, and the distance between the electrodes is adjusted to be uniform along the longitudinal direction. can do. Therefore, the flow of the plasma can be made uniform in the longitudinal direction, and the surface treatment can be performed uniformly. In addition, it is possible to make the gas flow easier by increasing the distance between the electrodes, or to facilitate the discharge by reducing the distance between the electrodes.

The access means desirably prevents each electrode from being distorted away from the other electrode.
This can prevent the gap between the electrodes from becoming non-uniform due to a difference in thermal expansion or the like when an electric field is applied, and secure uniform processing.

Preferably, the separating means prevents each electrode from being distorted so as to approach the other electrode.
This can prevent the gap between the electrodes from becoming non-uniform due to the Coulomb force, the difference in thermal expansion, and the like when an electric field is applied. Therefore, the plasma flow can be reliably and uniformly blown along the longitudinal direction of the electrode, and the surface treatment can be surely and uniformly performed.

A rigid member is provided on the back of each electrode opposite to the other electrode, and the access means is screwed into the rigid member and pressed against the back of the electrode to push the electrode. The separating means includes a pull bolt (pull screw member) having a head hooked on the rigid member and a leg screwed into the electrode to pull the electrode toward the rigid member. Is desirable.
Thereby, the structure of the approaching means and the separating means can be simplified. Further, by adjusting the screwing amount of these push-pull bolts, it is possible to easily correct the distortion of each electrode and adjust the interval between the electrodes.

A holder for supporting the pair of electrodes, the holder having the rigid members provided on the backs of the electrodes, and a connection reinforcing member for connecting and integrating the rigid members to reinforce them; Is desirable.
This makes it possible to reinforce the pair of rigid members so that they are not deformed, and thus it is possible to reliably prevent or correct the distortion of each electrode or to adjust the distance between the electrodes.

A gas introducing device for introducing a processing gas from a processing gas source to a processing gas receiving portion of the pair of electrodes, wherein the gas introducing device faces approximately half of the processing gas flow each other along the longitudinal direction. And a pair of uniformized paths that gradually leak out of the road from the substantially full length area of the peripheral side while flowing so as to form a plurality of elongated paths each extending in the longitudinal direction and communicating with one or more communication paths for each step. A step equalizing chamber is formed, and the first stage equalizing chamber forms an off-road space of the pair of equalizing paths, and each communication path is substantially the same as the step equalizing chambers before and after to be communicated. It is desirable that a slit-like shape or a plurality of spots covering the entire length region is formed, and that the final-stage homogenization chamber be continuous over substantially the entire length of the processing gas receiving portion of the pair of electrodes.
As a result, the processing gas can be introduced between the electrodes in a state where the processing gas is made uniform in the longitudinal direction of the electrodes, and the blown-out plasma flow can be made uniform without fail, and thus the plasma surface treatment can be made surely and uniformly. The communication passage may have a plurality of spots (pores) arranged at short intervals over substantially the entire length of the equalization chamber at the front and rear stages to be communicated.

The gas introduction device is configured such that members forming the pair of equalizing paths are housed in the elongated device main body along the parallel direction so as to bridge in the parallel direction. The inside of the device main body on the opposite side of the electrode with respect to the electrode is provided as the first-stage homogenizing chamber, and the inside of the device main body on the electrode side is provided as the second-stage and final-stage homogenizing chamber. Furthermore, it is desirable that the gaps on both sides of the apparatus main body and the uniformizing path constituting member along the direction in which the electrodes face each other are narrowed and provided as the communication paths.

The members constituting the pair of equalization paths include a pair of pipes extending in the same direction as the apparatus main body, and one end of one pipe and the other end of the other pipe serve as inlets for processing gas, respectively. It is desirable that a leak hole communicating with the first-stage homogenization chamber is formed in substantially the entire length of the pipe wall. The flow path cross-sectional area of the uniformizing path may be gradually reduced along the gas flow direction.

It is desirable that the processing gas be repeatedly split and merged, bend a plurality of times, and then be guided to the uniformizing path.
It is desirable that the gas introduction device and an electrode holder that supports the pair of electrodes be integrally connected.

INDUSTRIAL APPLICABILITY The present invention is applied to, for example, a normal pressure plasma process performed in an environment of approximately normal pressure (pressure near atmospheric pressure). Substantially normal pressure in the present invention refers to a range of 1.333 × 10 ^{4 to} 10.664 × 10 ⁴ Pa. In particular, the range of 9.331 × 10 ^{4 to} 10.297 × 10 ⁴ Pa is preferable because the pressure can be easily adjusted and the device configuration can be simplified.

According to the present invention, by preventing or correcting the distortion of the long electrode, it is possible to prevent the gap between the electrodes from becoming uneven. As a result, the plasma flow can be uniformly blown out along the longitudinal direction of the electrode, so that a uniform surface treatment can be performed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a remote type plasma processing apparatus S1 according to the present embodiment. The plasma processing apparatus S1 includes a mounting table 2 on which a large-area work (substrate, workpiece) W is mounted, and a plasma nozzle head 10 which is positioned on the mounting table 2 and supported by a mount (not shown). , A processing gas source 60, and a pulse power supply 1 (electric field applying means). A moving mechanism 3 is connected to the mounting table 2. As shown by the arrow in FIG. 1, the mounting table 2 and thus the work W are relatively moved in the front-rear direction (left and right in FIG. 1) by the moving mechanism 3. The mounting table 2 may be fixed, and the head 10 may be connected to the moving mechanism 3 so as to be movable.

The power supply 1 outputs, for example, a pulsed voltage to the electrode 20 described later. It is desirable that the rise time and / or fall time of this pulse be 10 μs or less, the electric field strength be 10 to 1000 kV / cm, and the frequency be 0.5 kHz or more.

The process gas source 60, the process gas in accordance with the processing contents (CF _4, etc.) are stored. It may be stored in a liquid phase and vaporized by an appropriate amount. A tube means 62 extends from the processing gas source 60. The tube means 62 has one common tube 63 connected to the processing gas source 60, and four (plural) branch tubes 64 branched from the common tube 63. The branch tube 64 extends so as to occupy most of the length of the tube means 62. The cross-sectional area of the flow passage of each branch tube 64 is a quarter of that of the common tube 63. Therefore, each of the branch tubes 64 can be made thinner, and the drawing can be facilitated. The branch tubes 64 are merged two by two, and the merge tube 65 extends therefrom. The cross-sectional area of the flow passage of each tube 65 is twice as large as that of the branch tube 64. These tubes 65 extend to the plasma nozzle head 10.

The plasma nozzle head 10 will be described in detail.
As shown in FIGS. 1 and 2, the nozzle head 10 includes a pair of long electrodes 20, an electrode holder 30 for holding the long electrodes 20, and a processing gas introducing device 11 disposed thereon. ing.

The gas introduction device 11 will be described.
As shown in FIGS. 1 to 3, the introduction device 11 includes a device main body 12 that is elongated in the left-right direction, and an inner pipe unit 40 (uniform path constituent member) housed in the device main body 12. . The apparatus main body 12 includes a main body 13 in the shape of an elongated container having an upper surface opened, a cap plate 14 fitted into and closing the upper surface opening of the main body 13, and a top plate superimposed on the cap plate 14. 15.

１〜 As shown in FIGS. 1 to 3 and FIG. 4A, a pair of end pieces 16 are provided on the left and right ends on the upper surface of the top plate 15, and a center piece 17 is provided at the center. Between each end piece 16 and the center piece 17, two upper pipes 51, 52 extending left and right are arranged back and forth two by two. The left and right rear upper pipes 51 are arranged in a straight line with each other with the center piece 17 interposed therebetween, and the front upper pipes 52 are arranged in a straight line with each other.

ガ ス The left and right end pieces 16 are formed with gas ports 16a connected to the rear upper pipe 51, respectively. One tube 65 of the tube means 62 is connected to the left port 16a, and the other tube 65 is connected to the right port 16a. As a result, the processing gas from the gas source 60 is guided from each port 16a into the upper pipe 51, and flows toward the center piece 17.

As shown in FIG. 4A, the center piece 17 is formed with a communication hole 17a for connecting the insides of the four upper pipes 51 and 52 to each other. As a result, the processing gases from the two rear upper pipes 51 are merged at the hole 17a, then diverted into the two front upper pipes 52, and flow toward the left and right ends.

よ う As shown in FIG. 2, a pair of end blocks 18 are provided on the left and right end plates of the main body 13. Each end block 18 is abutted on the lower surface of the end piece 16. As shown in FIGS. 1 and 3 to 5, the left and right end pieces 16 and the end block 18 are formed with a bent path 12 a extending from the upper pipe 52. That is, as shown in FIG. 3 and FIG. 4A, each end piece 16 has a path 16 b linearly continuous with the inside of the front upper pipe 52, and extends downward from this path 16 b to reach the lower surface of the end piece 16. A path 16c is formed. As shown in FIGS. 3 and 4B, an oval recess extending in the front-rear direction is formed on the upper surface of each end block 18, and the path 12 b is formed by the oval recess and the lower surface of the end piece 16. Is formed. The road 16c is connected to the front end of the road 12b. As shown in FIGS. 3 and 4B and 4C, each end block 18 has a path 18b extending downward from the rear end of the path 12b. As shown in FIGS. 3 and 5A, the left end block 18 is formed with a path 18c extending forward from the lower end of the path 18b. On the other hand, the right end block 18 is formed with a path 18c 'extending rearward from the lower end of the path 18b. As described later, these left and right paths 18c, 18c 'are respectively connected to pipes 41, 42 in front and behind the inner pipe unit 40.

The inner pipe unit 40 will be described.
As shown in FIG. 1, FIG. 3, and FIG. 5A, the unit 40 includes two inner pipes (uniform paths) 41, 42 extending left and right and arranged in front of each other, and the inner pipes 41, 42. Holding plates 43 and 44 for sandwiching 42 from above and below. Left and right ends of the inner pipes 41 and 42 are supported by left and right end plates of the main body 13. As shown in FIGS. 3 and 5A, the left end of the front inner pipe 41 is connected to the path 18c of the left end block 18, and the right end is closed. As shown in FIG. 5A, the right end of the rear inner pipe 42 continues to the path 18c 'of the right end block 18, and the left end is closed.

As shown in FIG. 1, FIG. 3 and FIG. 5A, small leak holes 41a and 42b penetrating from the inner peripheral surface to the outer peripheral surface are formed on the upper portions of the inner pipes 41 and 42 in the circumferential direction. , 42 are formed at short intervals over substantially the entire length area.

上下 As shown in FIG. 1, the upper and lower sandwiching plates 43, 44 straddle the front and rear inner pipes 41, 42, respectively. These holding plates 43 and 44 are connected by bolts 45 passed between the inner pipes 41 and 42, and thus hold the inner pipes 41 and 42. As shown in FIGS. 1, 3, and 4 (c), the upper sandwiching plate 43 has a large number of leak holes 43 a connected to the holes 41 a, 42 a of the inner pipes 41, 42. These leak holes 43a are opened on the upper surface of the holding plate 43.

As shown in FIGS. 1 and 3, between the cap plate 14 of the apparatus main body 12 and the upper holding plate 43, an elongated upper chamber (first-stage uniform chamber) 11a is formed on the left and right. The hole 43a of the holding plate 43 and the leak holes 41a and 42a of the inner pipes 41 and 42 are connected to the chamber 11a.

As shown in FIG. 1, FIG. 4 (c), and FIG. 5 (a), gaps 11c (slit-shaped communication passages) are formed between the front and rear side walls of the main body 13 and the inner pipes 41, 42, respectively. Have been. The gap 11c has the same thickness and is very narrow over the entire length of the inner pipes 4 and 42.

As shown in FIGS. 1, 3 and 5 (b), between the lower holding plate 44 and the bottom plate of the main body 13, a lower left and right elongated lower chamber (uniformization of the second and final stages). A chamber 11b is formed. The lower chamber 11b is connected to the upper chamber 11a via a gap 11c.
The communication path connecting the upper and lower chambers 11a and 11b may be a number of spot-like pores spaced apart in the left-right longitudinal direction instead of the slit shape.

As shown in FIGS. 1 and 5 (b), an introduction hole 13a is formed at the center of the bottom plate of the main body 13 in the width direction (front-rear direction) so as to extend over the entire left and right direction. The introduction hole 13a becomes wider on the upper surface of the bottom plate of the main body 13, and becomes narrower toward the lower surface.

Next, the electrode 20 of the plasma nozzle head 10 will be described.
As shown in FIGS. 1 and 3, the electrode 20 has a prismatic shape, and extends linearly and elongated in the left-right direction (the direction orthogonal to the paper surface of FIG. 1). The electrode 20 is made of, for example, a conductive material such as stainless steel. The pulse power supply 1 is connected to one (for example, rear) electrode 20, and the other (for example, front) electrode 20 is grounded.

、 As shown in FIGS. 1, 3, and 6, the pair of electrodes 20 are arranged in front of and behind each other at a small interval (for example, 2 mm) in parallel with each other. A plasma space 20a is formed between the opposing surfaces of the electrodes 30. The plasma generating space 20a has the same thickness over the entire length of the electrode 20. As described later, the processing gas is introduced into the space 20a from between the upper longitudinal edges (first longitudinal edges) of the electrode 20. Between the first longitudinal side edges is a processing gas receiving portion 20y in the shape of a left and right elongated slit. A pulse electric field is applied by the pulse power supply 1 to the plasma-forming space 20a between the electrodes. The processing gas is turned into plasma (activation, radicalization, ionization) in this electric field. Between the lower longitudinal side edges (second longitudinal side edges) of the electrodes 20, there are left and right narrow slit-shaped blowout holes 20 x (process gas blowout portions) for blowing the process gas plasmatized in the space 20 a downward. Has become.

The solid dielectric layer 21 is coated on the opposed surface and the lower surface of the electrode 20 by sandblasting and then spraying a dielectric such as ceramic. The back surface (outer surface) and the upper surface of the electrode 20 opposite to the opposing surface are polished so as to be flat and perpendicular to each other. Further, inside the electrode 20, cooling refrigerant reciprocating paths 20b and 20c are formed.

Next, the electrode holder 30 of the plasma nozzle head 10 will be described.
As shown in FIGS. 1 to 3, the electrode holder 30 includes a pair of front and rear insulating covers 31 provided on each electrode 20, a pair of front and rear side plates 33 attached to each insulating cover 31, and these members 31, The upper plate 33 extends between the upper surfaces of the upper plate 33 and extends in the left-right direction. The insulating cover 31 is made of an insulating resin such as polytetrafluoroethylene and has an upper piece 31x and a vertical piece 31y and is formed in an inverted L-shaped cross section. The upper pieces 31x of the pair of insulating covers 31 are opposed to each other via a narrow gap 31a at equal intervals over the entire length region. The gap 31a is continuous with the processing gas receiving portion 20y of the electrode 20 and the space 20a between the electrodes.

The polished surface of the electrode 20 at the right angle is exactly flush with the lower surface of the upper portion 31x of the insulating cover 31 and the inner surface of the vertical portion 31y (the surface facing the front-rear center of the head 10). Is attached. As shown in FIGS. 2 and 3, end plates 31 z are integrally provided at both ends in the longitudinal direction of the insulating cover 31, and the end plates 31 z are addressed to both end surfaces of the electrode 20. ing. As shown in FIG. 1, an elongated plate-shaped support member 37 is fixed to the lower end surface of the vertical piece portion 31y by bolting. The support member 37 slightly protrudes inward from the vertical piece 31y, and the outer corner of the lower end of the electrode 20 is placed and supported on this protruding portion.

The upper plate 32 (connection reinforcing member, reinforcing plate) is made of a rigid material such as steel. A slit 32a is formed in the upper plate 32 along the longitudinal direction facing left and right. The upper end of the slit 32a is continuous with the introduction hole 13a of the processing gas introduction device 11, and the lower end is continuous with the gap 31a between the pair of insulating covers 31 and the interelectrode space 20a.

As shown in FIGS. 1 and 2, the side plate 33 (a rigid member, a rigid plate) is formed in a long plate shape by a rigid material such as a steel material, and extends straight in the left-right direction while turning the width direction up and down. . The side plate 33 is addressed to the outer side surface (rear surface) of the vertical piece 31y of the insulating cover 31, and the upper edge thereof is abutted against the upper plate 32 and is bolted. Thus, the pair of front and rear side plates 33 is connected and integrated via the upper plate 32, and is reinforced so as not to be relatively deformed.

電極 The electrode holder 30 of the plasma nozzle head 10 is provided with a distortion correcting mechanism for correcting the original distortion generated in the manufacturing stage of the electrode 20 and the like, and a distortion preventing mechanism for preventing the distortion generated by applying an electric field. The distortion correcting mechanism includes a plurality of separating means 35 and 36 for separating the electrode 20 from the other electrode, and a plurality of approach means 34 for making the electrode 20 approach. The strain prevention mechanism includes a plurality of approach strain prevention means 35 and 36 for preventing the electrode 20 from being distorted so as to approach the other electrode, and a plurality of separated strain prevention means for preventing the electrode 20 from being distorted away from the other electrode. 34. The separating means and the approaching strain preventing means are constituted by the same members 35 and 36, and the approaching means and the approaching strain preventing means are constituted by the same member 34. Further, the distortion correcting mechanism (a plurality of separating means and a plurality of approaching means) also constitutes an interval adjusting mechanism for adjusting an interval between the pair of electrodes 20.

Specifically, as shown in FIGS. 1, 2 and 6, a plurality of electrode pushing bolts 34 and electrode pulling bolts 35 are provided on the side plate 33 so as to be separated from each other in the longitudinal direction. The push bolt 34 (approaching means of the distortion correcting mechanism (or the gap adjusting mechanism) and separating / distorting preventing means of the distortion preventing mechanism) is screwed into the screw hole 33a of the side plate 33 and penetrates the same. Of the recess 31c. As a result, it abuts on the back surface of the electrode 20 via the insulating cover 31. By further screwing the push bolt 34, the electrode 20 can be pushed through the insulating cover 31.

As shown in FIGS. 1 and 6, the side plate 33 and the insulating cover 31 are provided with a plurality of accommodation holes 33b, 31b separated from each other in the longitudinal direction. A stepped tubular pull bolt holder 36 is accommodated in these accommodation holes 33b and 31b. A flange 36 a is provided at an outer end of the bolt holder 36, and the flange 36 a contacts a step 33 c of the receiving hole 33 b of the side plate 33. The bolt holder 36 has a large-diameter hole 36b formed on the outer end side along the central axis thereof, and a small-diameter hole 36c formed on the inner end side. A pull bolt 35 is inserted into these holes 36b and 36c. The head of the pull bolt 35 abuts a step between the holes 36b and 36c, and the legs are screwed into the screw holes 20d of the electrode 20 through the small-diameter holes 36c.

When the electrode 20 is distorted in the manufacturing process or the like and a gap is formed between the electrode 20 and the cover vertical piece 31y, if the draw bolt 35 is screwed tightly, the electrode 20 is pulled to hit the cover vertical piece 31y (the other side). Away from the electrode 20). When the electrode 20 is distorted by Coulomb force or the like so as to approach the other electrode 20 side, the head of the pull bolt 35 is caught by the step between the holes 36b and 36c of the bolt holder 36, and furthermore, The flange 36a is hooked on the step 33c of the side plate 33. (Consequently, the head of the pull bolt 35 is hooked on the side plate 33 via the bolt holder 36.) This prevents the electrode 20 from approaching (distorting) to the other electrode 20 side. .
The pull bolt 35 and the holder 36 constitute "separating means of a distortion correcting mechanism (or an interval adjusting mechanism)" and also constitute "approaching distortion inhibiting means of a distortion inhibiting mechanism".

The operation of the plasma processing apparatus S1 configured as described above will be described.
The processing gas from the gas source 60 passes through the common tube 63, is divided into four by the branch tube 64, and then merges two by two and flows through the two tubes 65. After passing through these tubes 65, they are introduced into the left and right ports 16a of the nozzle head 10 and flow through the left and right rear upper pipes 51 toward the center of the device 11, respectively. Then, after merging into one in the communication hole 17 a of the center piece 17, the flow is divided into approximately half, guided to the left and right front upper pipes 52, and flows toward the left and right ends. Furthermore, it is bent at right angles a plurality of times on the left and right bending paths 12a. As described above, the processing gas flow can be leveled by repeating the branching, merging, and bending.

(4) The processing gas flows after passing through the left and right bent paths 12a are sent into the inner pipes 41 and 42, respectively. The processing gas entering the left end of the front inner pipe 41 from the left bent path 12a flows to the right inside the pipe 41, passes through the leak holes 41a, 43a arranged in this flow direction, and passes through the upper chamber 11a (uniform path). Gradually leaks out). Similarly, the processing gas that has entered the right end of the rear inner pipe 42 from the right bent path 12a flows through the pipe 42 to the left, passes through the leak holes 42a, 43a, and passes through the upper chamber 11a (outside the uniform path). Leaks gradually to. At this time, in each of the pipes 42, the flow rate and the flow velocity of the processing gas gradually change along the flow. However, the above-mentioned tendency is canceled by mutually flowing the processing gas through the two pipes 42. Can be. Thereby, the processing gas can be substantially uniformly introduced into the upper chamber 11a in the left-right direction. Since the upper chamber 11a has a sufficiently large volume, the processing gas can be temporarily set to a static pressure in the chamber 11a.

(4) Further, the processing gas flows from the entire length of the upper chamber 11a to the lower chamber 11b through the narrow gap 11c. At this time, a pressure loss occurs in the gap 11c, and the gas having a high pressure tends to flow into a lower pressure. Thereby, the gas flow can be sent to the lower chamber 11b with more uniformity in the left-right direction. The processing gas becomes static pressure again in the chamber 11a. Then, the pair of electrodes 20 is received in the receiving portion 20y between the upper longitudinal side edges of the pair of electrodes 20 through the introduction hole 13a, the slit 32a, and the gap 31a sequentially from the chamber 11b. Thus, the processing gas can be uniformly introduced into the plasma-forming space 20a between the electrodes 20 along the left-right longitudinal direction.

On the other hand, the pulse voltage from the pulse power supply 1 is applied between the electrodes 20, and a pulse electric field is formed in the space 20a. As a result, glow discharge occurs in the space 20a, and the processing gas is turned into plasma. Since the processing gas is made uniform in the left-right direction, the plasma can also be made uniform in the left-right direction. The uniform plasma flow is blown onto the work W from the blowout holes 20x, so that the upper surface of the work W can be subjected to a uniform surface treatment.

 In addition, even if Coulomb attraction acts between the long electrodes 20 due to the applied electric field, the head of the pull bolt 35 screwed into the electrode 20 is caught on the side plate 33 via the bolt holder 36, so that each electrode 20 is connected to the other side. Can be prevented from being pulled toward the electrode 20. Also, inside the long electrode 20, the portion on the other electrode side becomes hotter than the portion near the back surface, or approaches the other electrode due to the difference in the coefficient of thermal expansion with the solid dielectric layer 21. Even in the case of distortion, similarly to the above, the distortion in the approaching direction can be prevented by the pull bolt 35. On the other hand, when the long electrode 20 is to be distorted so as to move away from the other electrode due to the difference in thermal expansion or the like, the push bolt 34 is pressed from the back via the insulating cover 31, and thus, in the separation direction. Distortion can be prevented. Thus, the long electrodes 20 can be kept straight, and the distance between the electrodes 20, that is, the thickness of the plasma space 20a can be kept uniform. As a result, the plasma flow can be more reliably and uniformly blown along the longitudinal direction of the electrode 20, and a uniform surface treatment can be performed more reliably.

In the plasma nozzle head 10, even if the electrode 20 is distorted by the thermal spraying process of the solid dielectric layer 21 or the polishing process of the reference surface in the manufacturing process of the electrode 20, the push-pull bolts 34 and 35 are adjusted to adjust the push-pull bolts 34 and 35. The distortion of the electrode 20 can be corrected and the electrode 20 can be straightened. As a result, the thickness of the plasma generating space 20a can be reliably made uniform. As a result, the blown plasma flow can be more reliably made uniform, and a more uniform surface treatment can be performed. Further, the thickness of the space 20a can be increased to facilitate gas flow, and the thickness of the space 20a can be reduced to facilitate glow discharge.

The present invention is not limited to the above embodiment, and various modifications are possible.
For example, the electrode 20 has a prismatic shape (thick plate shape) in the above embodiment, but may be formed in a thin plate shape. This makes it possible to reduce the overall size and weight of the nozzle head 10. Even if the electrode 20 has a thin plate shape, the pull bolt 35 (blocking means) can resist Coulomb force and prevent distortion.
The length of the electrode 20 in the longitudinal direction may be set according to the size of the work W. Here, the longer the electrode 20 is made to be 50 cm, 80 cm, and 110 cm, the greater the generated Coulomb force, so the number of pull bolts 35 may be set according to the Coulomb force.
The approach distortion preventing means may be a stopper provided on the electrode holder so as to be hooked on the electrode.
The separating means as the distortion correcting means (or the distance adjusting mechanism) may be provided separately from the approaching strain preventing means, or the approaching means may be provided separately from the separating distortion preventing means.
In the above embodiment, the processing gas is converted into plasma by glow discharge, but may be formed by arc discharge or the like. Although a pulse power supply is used as the electric field applying means, a high-frequency power supply such as a resonance power supply may be used.
The present invention can be applied not only to normal pressure, but also to plasma processing under reduced pressure, and can be applied not only to glow discharge but also to plasma processing by corona discharge or creeping discharge. The present invention can be widely applied to various plasma treatments such as surface modification and ashing.

FIG. 7 is a side step cross-sectional view illustrating the plasma processing apparatus according to the embodiment of the present invention along the line II in FIG. 6. FIG. 3 is a perspective view of a plasma nozzle head of the plasma processing apparatus. FIG. 3 is a front sectional view of the plasma nozzle head taken along a line III-III in FIG. 1. (A) is a sectional plan view of the processing gas introduction device of the plasma nozzle head taken along the line IVA-IVA of FIG. 1, and (b) is a processing of the plasma nozzle head taken along the line IVB-IVB of FIG. 1. FIG. 4 is a plan cross-sectional view of the gas introducing device, and FIG. 4C is a plan cross-sectional view of the processing gas introducing device of the plasma nozzle head taken along line IVC-IVC in FIG. 1. (A) is a plane sectional view of the processing gas introduction device of the plasma nozzle head along the line VA-VA of FIG. 1, and (b) is a processing of the plasma nozzle head along the line VB-VB of FIG. 1. It is a plane sectional view of a gas introduction device. FIG. 6 is a plan sectional view of the electrode holder of the plasma nozzle head, taken along line VI-VI of FIG. 1.

Explanation of reference numerals

W Work (object to be processed)
S1 Plasma processing device 1 Pulse power supply (electric field applying means)
Reference Signs List 10 Plasma nozzle head 11 Processing gas introduction device 11a Upper chamber (first-stage homogenization chamber)
11b Lower chamber (second and final stage equalization chamber)
11c Clearance (communication passage)
20 Long electrode 20a Plasma conversion space (space between opposing surfaces of electrodes)
20x blowout hole (process gas blowout part)
20y Process gas receiving portion 30 Electrode holder 32 Upper plate (connection reinforcing member)
33 Side plate (rigid member)
34 Push bolt (approaching means, separating strain prevention means)
35 Pull bolt (component of separation means and approach strain prevention means)
36 Pull bolt holder (component of separation means and approach strain prevention means)
41, 42 Inner pipe (uniform path)
60 Processing gas source

Claims (13)

A pair of long electrodes are arranged in parallel, an electric field is applied between the electrodes, and a processing gas is introduced between the first longitudinal side edges of the electrodes and between the opposing surfaces. In a plasma processing apparatus that blows out from between the longitudinal side edges of
A plasma processing apparatus comprising a distortion preventing mechanism for preventing each electrode from being distorted in the arrangement direction. 2. The plasma processing apparatus according to claim 1, wherein the distortion prevention mechanism includes an approach distortion prevention unit that prevents each electrode from being distorted so as to approach the other electrode. 3. The plasma processing apparatus according to claim 2, wherein a plurality of the approach strain preventing means are provided apart from each other in a longitudinal direction of the electrode. A rigid member is provided on the back of each electrode opposite to the other electrode,
The plasma processing apparatus according to claim 2, wherein the approach distortion preventing means includes a bolt having a head hooked on the rigid member and a leg screwed into the electrode. 5. The strain prevention mechanism includes approach strain prevention means for preventing each electrode from being distorted so as to approach the other electrode, and separation strain prevention means for preventing each electrode from being distorted away from the other electrode. The plasma processing apparatus according to claim 1, wherein: A plurality of approaching means for bringing each electrode closer to the other electrode side, and a plurality of separating means for keeping away from each other are provided in the longitudinal direction of the electrodes, respectively.
The approach means also serves as the separation strain prevention means by preventing separation of the electrodes,
6. The plasma processing apparatus according to claim 5, wherein said separating means also serves as said approach distortion preventing means by preventing approach of the electrode. A rigid member is provided on the back of each electrode opposite to the other electrode,
The approaching means, i.e., the separation strain preventing means, includes a push bolt screwed into the rigid member and pressed against the back surface of the electrode to push the electrode.
The separation means, i.e., the approach strain preventing means, includes a pull bolt which has a head hooked to the rigid member and a leg screwed into the electrode to pull the electrode toward the rigid member. 7. The plasma processing apparatus according to 6. A pair of long electrodes are arranged in parallel, an electric field is applied between the electrodes, and a processing gas is introduced between the first longitudinal side edges of the electrodes and between the opposing surfaces. In a plasma processing apparatus that blows out from between the two longitudinal side edges,
A plurality of approaching means that are arranged apart from each other in the longitudinal direction of the electrode and bring each electrode closer to the other electrode side;
A plurality of separation means arranged apart from each other in the longitudinal direction, and separating each electrode from the other electrode;
A plasma processing apparatus comprising: 9. The plasma processing apparatus according to claim 8, wherein said approaching means prevents each electrode from being distorted so as to move away from the other electrode. 10. The plasma processing apparatus according to claim 8, wherein the separating unit prevents each electrode from being distorted so as to approach the other electrode. A rigid member is provided on the back of each electrode opposite to the other electrode,
The access means includes a push bolt screwed into the rigid member and pressed against the back surface of the electrode to push the electrode;
11. The method according to claim 8, wherein the separating means includes a pull bolt having a head hooked on the rigid member and a leg screwed into the electrode to pull the electrode toward the rigid member. A plasma processing apparatus according to any one of the above. A holder for supporting the pair of electrodes, the holder having the rigid members provided on the backs of the electrodes, and a connection reinforcing member for connecting and integrating the rigid members to reinforce them; The plasma processing apparatus according to claim 4, 7, or 11, wherein A gas introduction device that guides a processing gas from a processing gas source to a processing gas receiving portion of the pair of electrodes,
In this gas introduction device, a pair of uniformized paths that gradually leak out of the road from substantially the entire length area of the peripheral side while flowing approximately half of the processing gas flow so as to face each other along the longitudinal direction, A plurality of stages of uniform chambers each having an elongated shape along the longitudinal direction and communicating with one or more communication paths for each stage are formed,
The first-stage equalization chamber forms an off-road space of the pair of equalization paths,
Each communication passage has a slit shape or a plurality of spot shapes covering substantially the entire length of the equalization chamber of the stage before and after the communication,
The plasma processing apparatus according to any one of claims 1 to 12, wherein the homogenization chamber at the last stage extends over substantially the entire length of the processing gas receiving portion of the pair of electrodes.

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