JP2008147106A - Plasma processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing device with a comparatively simple structure, regardless of a processing surface shape of a work, and capable of carrying out a plasma treatment in accordance with its shape. <P>SOLUTION: The plasma processing device 1 includes a work mounting part 21 mounting a work, a first electrode 2, and a second electrode 3 of a cylindrical shape placed in the opposite side of the first electrode 2 of the work mounting part 21, mounted to be faced to a processing surface 11 of a work 10 the outer peripheral surface of which is faced to the work mounting part 21, and capable of rotating a center axis as a rotation axis, and processes the processing surface 11 by generated plasma. The second electrode 3 contains a part changing a width of an effective electrode region 31a along a peripheral direction on its outer peripheral surface. The second electrode 3 is structured to change a width of the effective electrode region 31 facing to the processing surface 11 by rotating the center axis as a rotation axis. <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 and perform plasma processing on the surface of a workpiece that is an object to be processed are known.
Such a plasma processing apparatus has electrodes arranged opposite to each other, and supplies a predetermined gas into a gap formed between a pair of electrodes while applying a voltage between these electrodes. This generates a discharge and generates 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. When these active species are supplied to the surface of the workpiece, various reactions occur on or near the surface of the workpiece due to a part of the active species, and the surface (treated surface) of the workpiece is decomposed and removed. Yes.

  For example, Patent Document 1 includes a first electrode 102 and a second electrode 103 each formed in a cylindrical shape as shown in FIG. 5, while applying a voltage between the electrodes 102 and 103 facing each other. There has been proposed a plasma processing apparatus that applies plasma processing to the processing surfaces of the workpieces 110 and 110 ′ by passing the workpieces 110 and 110 ′ between the electrodes 102 and 103 in a state where a processing gas for generating plasma is supplied. Yes.

In such a plasma processing apparatus, since processing is performed in a state in which almost the entire electrodes 102 and 103 are covered with the surface of the workpiece, when the plasma processing is performed on the surface of the workpiece 110 having a wide width, the electrodes 102 and 103 facing each other. In a state as shown in FIG. 5A, the workpiece 110 is moved in the direction of the arrow in the drawing to treat the surface of the workpiece 110, and the surface of the workpiece 110 ′ having a narrow width is further removed. In the case of performing the plasma processing, the surface of the workpiece 110 ′ is processed by moving the workpiece 110 ′ in the direction of the arrow in the state in which the electrodes 102 and 103 are arranged at the positions as shown in FIG. .
As described above, the processing is performed in a state in which almost the entire electrodes 102 and 103 are covered with the surface of the workpiece, thereby realizing an improvement in the quality of the processing surface of the workpiece and an improvement in the processing speed.

However, the plasma processing apparatus described in Patent Document 1 has a problem that it takes time to align the electrodes 102 and 103 in accordance with the shape of the workpiece. In particular, in order to align the electrodes 102 and 103 with respect to a workpiece having a curved surface such as a circular workpiece, it is necessary to align the electrodes 102 and 103 over time as the workpiece moves. Yes, it is extremely difficult.
Further, as shown in FIG. 5, the electrodes 102 and 103 are arranged so as to be inclined with respect to the longitudinal direction of the workpiece. , 103 is inevitably generated, and as a result, the power supplied to the electrodes 102, 103 is wasted.

JP 2003-22899 A

  An object of the present invention is to provide a plasma processing apparatus capable of performing plasma processing in accordance with a shape of a workpiece with a relatively simple configuration regardless of the shape of a processing surface of a workpiece.

Such an object is achieved by the present invention described below.
The plasma processing apparatus of the present invention, a work installation unit for installing a work,
A first electrode;
It is located on the side opposite to the first electrode of the workpiece installation section, and is installed so that the outer peripheral surface faces the processing surface of the workpiece installed in the workpiece installation section, and is rotatable about the central axis as a rotation axis A cylindrical second electrode;
Gas supply means for supplying a processing gas for generating plasma in a gap between the second electrode and the workpiece;
A power supply circuit having a power supply for applying a high frequency voltage between the first electrode and the second electrode so that the processing gas supplied to the gap is turned into plasma,
A plasma processing apparatus for processing a processing surface of the workpiece with generated plasma,
The second electrode has a portion in which the width of the effective electrode region is changed along the circumferential direction on the outer peripheral surface,
The width of the effective electrode region facing the processing surface of the workpiece is changed by rotating the central axis of the second electrode as a rotation axis.
Thereby, it is possible to perform plasma processing corresponding to the shape of the workpiece with a relatively simple configuration regardless of the shape of the workpiece processing surface.

In the plasma processing apparatus of the present invention, the second electrode is configured so that the width of the effective electrode region facing the processing surface of the workpiece gradually decreases or gradually increases as the central axis rotates in one direction. Preferably it is.
Thereby, the width of the effective electrode region changes continuously.
In the plasma processing apparatus of the present invention, when the second electrode is rotated, the center of the width of the effective electrode region facing the processing surface of the workpiece is displaced in the rotation axis direction of the second electrode. Preferably not.

In the plasma processing apparatus of the present invention, it is preferable that the center of the width of the effective electrode region facing the processing surface of the workpiece corresponds to the center of the width of the processing surface of the workpiece.
Thus, the second electrode can be positioned so that the width of the effective electrode region facing the workpiece processing surface corresponds to the width of the workpiece processing surface.

In the plasma processing apparatus of the present invention, the second electrode is configured such that, on the outer peripheral surface, the effective electrode region protrudes from a portion other than the effective electrode region, whereby the distance to the processing surface is reduced. It is preferable that
Thereby, plasma can be generated preferentially in the effective electrode region.
In the plasma processing apparatus of the present invention, it is preferable that the second electrode is configured such that, on the outer peripheral surface, the effective electrode region has higher conductivity than a portion other than the effective electrode region.
Thereby, plasma can be generated preferentially in the effective electrode region.
The plasma processing apparatus of the present invention preferably has a control means for controlling the rotation of the second electrode.
Thereby, the width | variety of the effective electrode area | region which faces the process surface of a workpiece | work can be adjusted with a control means.

In the plasma processing apparatus of the present invention, the control means rotates the second electrode so that the width of the effective electrode region facing the processing surface of the workpiece corresponds to the width of the processing surface of the workpiece. It is preferable to control.
Thereby, the processing surface can be plasma-treated corresponding to the width.

In the plasma processing apparatus of the present invention, when processing the workpiece whose width of the processing surface of the workpiece changes relative to the second electrode,
While the second electrode is rotated by the control means, the width of the effective electrode area facing the processing surface of the workpiece is made to correspond to the width of the processing surface of the workpiece, and the processing surface of the workpiece is processed. It is preferable.
Thereby, it is possible to perform plasma processing corresponding to the width of the processing surface even on a processing surface having a curved portion such as a circular shape, and plasma processing can be performed on almost the entire processing surface.

In the plasma processing apparatus of the present invention, the power density between the first electrode and the second electrode, which is generated by changing the width of the effective electrode region facing the processing surface of the workpiece. It is preferable to adjust a relative moving speed of the workpiece with respect to the second electrode so as to reduce a change in size.
Thereby, it is suppressed that a difference arises in the processing rate of a processing surface, As a result, the processing nonuniformity of a processing surface is relieved.

In the plasma processing apparatus of the present invention, the power density between the first electrode and the second electrode, which is generated by changing the width of the effective electrode region facing the processing surface of the workpiece. It is preferable to adjust the magnitude of electric power applied between the first electrode and the second electrode by the power supply circuit so as to reduce the change in magnitude.
Thereby, it is suppressed that a difference arises in the processing rate of a processing surface, As a result, the processing nonuniformity of a processing surface is relieved.

In the plasma processing apparatus of the present invention, it is preferable that the gas supply means has a gas adjusting means capable of changing a supply amount of the processing gas supplied per unit time.
In the plasma processing apparatus of the present invention, it is preferable that the gas adjusting unit changes a supply amount of the processing gas according to a width of the effective electrode region facing the processing surface of the workpiece.
Thereby, plasma can be reliably generated between the processing surface and the effective electrode region without supplying an excessive amount of processing gas. As a result, it is possible to reduce the amount of processing gas that is wasted.

Hereinafter, the plasma processing apparatus of the present invention will be described in detail based on the illustrated preferred embodiments.
<First Embodiment>
First, a first embodiment of the plasma processing apparatus of the present invention will be described.
FIG. 1 is a perspective view (including a partial block diagram) schematically showing a first embodiment of a plasma processing apparatus of the present invention, and FIG. 2 is a configuration of a second electrode provided in the plasma processing apparatus shown in FIG. FIG. 3 is a perspective view (including a partial block diagram) schematically showing a case where a wide workpiece is processed by the plasma processing apparatus of the first embodiment. is there. In the following description, the upper side in FIGS. 1 and 3 is referred to as “upper” and the lower side is referred to as “lower”.
A plasma processing apparatus 1 shown in FIG. 1 performs various plasma processes such as an etching process, an ashing process, a hydrophilic process, a water repellent process, and a film forming process on a workpiece 10.
Hereinafter, an example of an etching process in which the plasma processing apparatus 1 performs plasma processing on the processing surface 11 of the workpiece 10 and decomposes and removes the processing surface 11 will be described.

  A plasma processing apparatus 1 shown in FIG. 1 is a plasma processing apparatus that performs etching on a workpiece by the action of generated atmospheric pressure (normal pressure) plasma. The first electrode supports and conveys the workpiece 10. 2, a second electrode 3 installed above the first electrode 2 via the work 10, a power supply circuit 4 for applying a voltage between the first electrode 2 and the second electrode 3, A gas supply unit (gas supply means) 5 for supplying a processing gas is provided between the workpiece 10 and the second electrode 3.

The plasma processing apparatus 1 also includes a control unit 6 that controls the operation of each unit of the plasma processing apparatus 1 and an operation unit (input unit) 7 that performs each operation such as input.
Hereinafter, each part will be described in detail.
Here, prior to the description of the plasma processing apparatus 1, the workpiece 10 to be etched by the plasma processing apparatus 1 will be described.

The workpiece 10 is subjected to etching processing on an upper surface (hereinafter also referred to as “processed surface”) 11 by the plasma processing apparatus 1.
Examples of the material constituting the workpiece 10 include materials that can react with activated atoms (radicals) contained in plasma, which will be described in detail later.
Examples of such a material include silicon-based materials such as Si, SiO ₂ , SiN, and Si ₃ N ₄ , Al, Au, Cr, Cu, Ga, Mo, Nb, Ta, Ti, V, W, and these Examples thereof include various metal materials such as alloys containing metals, organic materials such as polyolefin and polyimide, glass materials such as quartz glass and borosilicate glass, C, and GaAs.

The shape of the workpiece 10 (the shape in plan view) is not particularly limited and is, for example, a rectangle, a square, a circle, an oval, or the like. In this embodiment, the shape is a rectangle as shown in FIG. The case will be described as an example.
Although the thickness of the workpiece | work 10 is not specifically limited, Usually, it is preferable that it is about 0.03-1.2 mm, and it is more preferable that it is about 0.05-0.7 mm.

The first electrode 2 supports the entire lower surface (surface opposite to the processing surface 11 described later) of the workpiece 10 in the workpiece setting portion 21 for setting the workpiece 10 provided on the upper surface. Thereby, an electric field can be applied over the entire workpiece 10.
Further, the first electrode 2 can be moved in the arrow direction in FIG. 1, that is, in the X-axis direction by the operation of a transport means (not shown) connected to the first electrode 2.
The constituent material of the first electrode 2 is not particularly limited as long as it has conductivity and nonmagnetic properties. For example, a simple metal such as copper, aluminum, gold, silver, stainless steel, brass, aluminum Examples thereof include conductive materials having good conductivity such as various alloys such as alloys, intermetallic compounds, and various carbon materials.

On the other hand, the second electrode 3 is disposed to face the first electrode 2 with the work 10 interposed therebetween. In other words, the second electrode 3 is disposed on the opposite side (opposite side) of the first electrode 2 of the work installation portion 21.
A high frequency voltage is applied between the first electrode 2 and the second electrode 3 by a power supply circuit 4 described later. When a high-frequency voltage is applied between these electrodes 2 and 3, gas molecules existing between the workpiece 10 and the second electrode 3 are ionized, and plasma can be generated.
The configuration of the second electrode 3 will be described in detail later.

The power supply circuit 4 applies a high frequency voltage between the first electrode 2 and the second electrode 3. Thereby, an electric field whose direction is reversed at a high frequency is induced in the gap between the first electrode 2 and the second electrode 3.
Such a power supply circuit 4 includes a high frequency power supply 41, a matching box (matching box) 44 that performs impedance matching, a switch 45 that opens and closes the power supply circuit 4, a high frequency power supply 41 and the first electrode 2. And a wiring 43 for connecting the high-frequency power source 41 and the second electrode 3 via a matching unit 44. In addition, a part of the power supply circuit 4, that is, in this embodiment, the wiring 42 on the first electrode 2 side is grounded (grounded).

The frequency of the high-frequency voltage is not particularly limited, but is preferably about 1 kHz to 100 MHz, and more preferably about 10 to 60 MHz. Thereby, plasma can be generated stably.
Moreover, although the output of a high frequency power supply changes with areas of the 1st electrode 2 and the 2nd electrode 3, it is preferable that it is about 10W-10kW, and it is more preferable that it is about 50W-1kW. Thereby, plasma can be generated more stably.

The gas supply unit (gas supply means) 5 has a function of supplying a processing gas between the workpiece 10 and the second electrode 3.
A gas supply unit 5 shown in FIG. 1 includes a nozzle 51 having an opening for ejecting a processing gas at a position where the processing surface 11 of the workpiece 10 and the second electrode 3 face each other, and an upstream side of the nozzle 51. A gas cylinder (gas supply source) 52 that is connected to the end side and supplies and supplies the processing gas, and a regulator that can vary the flow rate (supply amount) of the gas supplied from the gas cylinder 52 per unit time. (Gas adjusting means) 53 and a supply pipe 55 for connecting these parts 51, 52, 53.

The regulator 53 is disposed on the opening side (downstream side) from the gas cylinder 52. Further, between the nozzle 51 and the regulator 53, a valve (flow path opening / closing means) 54 that opens and closes the flow path of the processing gas into the nozzle 51 is provided.
With the valve 54 opened, a processing gas is sent out from the gas cylinder 52. The processing gas flows through the supply pipe 55, and after the flow rate is adjusted by the regulator 53, the processing gas is formed at the downstream end of the supply pipe 55. The gas is introduced (supplied) between the second electrode 3 and the processing surface 11 of the workpiece 10 by being supplied into the nozzle 51 and ejected from the opening from the gas outlet.
The processing gas supplied by the gas supply unit 5 having such a configuration is one in which contained gas molecules are ionized by the action of a high-frequency voltage to generate plasma.

Various gases can be used as the processing gas depending on the processing purpose. In the case of aiming at the dicing process in addition to the purpose of the etching process as in the present embodiment, for example, CF ₄ , C ₂ F ₆ , C ₃ F ₆ , C ₄ F ₈ , CClF ₃ , SF Various halogen-based gases such as a fluorine atom-containing compound gas such as ₆ and a chlorine atom-containing compound gas such as Cl ₂ , BCl ₃ , and CCl ₄ are used.

Further, in the case of other processing purposes, the following processing gases can be used for each purpose.
(A) For the purpose of heating the processing surface 11 of the workpiece 10, for example, N ₂ , O ₂ or the like is used.
(B) For the purpose of making the treated surface 11 of the workpiece 10 water repellent (liquid repellent), for example, the fluorine atom-containing compound gas is used.

(C) When the treatment surface 11 of the workpiece 10 is made hydrophilic (lyophilic), for example, an oxygen atom-containing compound such as O ₃ , H ₂ O, air, or a nitrogen atom such as N ₂ or NH ₃ Sulfur atom-containing compounds such as containing compounds, SO ₂ and SO ₃ are used. Thereby, hydrophilic functional groups, such as a carbonyl group, a hydroxyl group, and an amino group, are formed on the processing surface 11 of the workpiece 10 to increase the surface energy and obtain a hydrophilic surface. Alternatively, a hydrophilic polymer film can be deposited (formed) using a polymerizable monomer having a hydrophilic group such as acrylic acid or methacrylic acid.

(D) When the purpose is to add electrical and optical functions to the processing surface 11 of the workpiece 10, a metal oxide thin film such as SiO ₂ , TiO ₂ , SnO ₂ or the like is formed on the processing surface 11 of the workpiece 10. For this purpose, metal metal-hydrogen compounds, metal-halogen compounds, metal alkoxides (organometallic compounds) such as Si, Ti and Sn are used.
(E) For the purpose of resist treatment or removal of organic contamination, for example, oxygen-based gas is used.

Such a processing gas is generally used by adding a carrier gas to the processing gas. The “carrier gas” refers to a gas introduced for starting discharge and maintaining discharge.
In this case, the gas cylinder 52 may be filled with the processing gas and the carrier gas, or the processing gas and the carrier gas are filled in different gas cylinders, and these are mixed in the supply pipe 55 at a predetermined mixing ratio. It may be configured to be mixed in the above.
As the carrier gas, a rare gas such as He, Ne, Ar, or Xe can be used. These can be used alone or in a mixed form of two or more.

The ratio (mixing ratio) of the processing gas in the gas to which the carrier gas is added varies slightly depending on the purpose of the processing and is not particularly limited. For example, the ratio of the processing gas is about 0.1 to 10%. Is preferable, and about 0.3 to 4% is more preferable. Thereby, discharge is efficiently started, and a desired plasma treatment can be performed with the treatment gas.
The flow rate of the processing gas is appropriately determined according to the type of gas, the purpose of processing, the degree of processing, and the like. Usually, it is preferably about 30 SCCM to 2 SLM. Thereby, the processing surface 11 of the workpiece | work 10 can be efficiently plasma-processed.

The operation unit 7 is used by an operator or the like to perform various operations such as input.
As the operation unit 7, for example, a touch panel provided with a keyboard, a liquid crystal display panel, an EL display panel, or the like can be used. In this case, the operation unit 7 is a display unit that displays (notifies) various types of information. Also serves as (notification means).
The storage unit 8 stores various types of information such as the width of the processing surface 11 of the workpiece 10 input from the operation unit 7, data, arithmetic expressions, tables, programs, and the like (also referred to as recording). There is a medium (also called a recording medium), and this storage medium is rewritable (erasable and rewritable), for example, volatile memory such as RAM, nonvolatile memory such as ROM, EPROM, EEPROM, flash memory, etc. Various non-volatile memories, various semiconductor memories, IC memories, magnetic recording media, optical recording media, magneto-optical recording media, and the like. Control such as writing (storage), rewriting, erasing, and reading in the storage unit 8 is performed by the control unit 6.

Furthermore, the control unit 6 is configured by a computer such as a microcomputer or a personal computer having a calculation unit, a memory, or the like, for example, and a signal (input) from the operation unit 7 is respectively input to the control unit 6. Input as needed. Then, the control unit 6 operates (drives) each part of the plasma processing apparatus 1 according to a preset program based on the signal from the operation unit 7, for example, the operation of the drive source 33, the regulator 53, the transporting unit, and the like. To control each.
In such a plasma processing apparatus 1, the operation of the drive source 33, which will be described later, is performed so that the control unit 6 performs plasma processing on the processing surface 11 in accordance with the width of the workpiece 10 input by the operation unit 7. It is configured to control.

  Now, in the plasma processing apparatus 1 of the present invention, the second electrode 3 is located on the opposite side of the work placement portion 21 from the first electrode 2, and its outer peripheral surface is placed so as to face the work placement portion 21. The cylindrical shape is rotatable around the central axis as a rotation axis. And this 2nd electrode 3 has a part in which the width | variety of the effective electrode area | region 31a is changing along the circumferential direction in the outer peripheral surface, and rotates the 2nd electrode 3 about the center axis | shaft By rotating as the shaft, the width W of the effective electrode region 31a facing the processing surface 11 of the workpiece 10 is changed.

  In the present embodiment, the effective electrode region 31a formed on the outer peripheral surface of the second electrode 3 has a width of the effective electrode region 31a from the outer peripheral surface of the second electrode 3 as shown in FIG. When it is cut and expanded in the width direction at the maximum position, it is constituted by three sides of a side 311, a side 312 and a side 313, and the lengths of the side 312 and the side 313 are equal. That is, the effective electrode region 31 a has an isosceles triangle in which the vertex 314 is located at the center of the width of the second electrode 3.

As shown in FIG. 1, the plasma processing apparatus 1 includes a rotation shaft 32 that can rotate the second electrode 3 and a drive source 33 that drives the rotation shaft 32 to rotate.
One end of the rotation shaft 32 is connected to the end of the second electrode 3, and the central axis thereof is provided so as to coincide with the central axis of the second electrode 3. A drive source 33 is connected to the other end of the rotation shaft 32. Therefore, the second electrode 3 can be rotated with its central axis as a rotation axis by the operation of the drive source 33.

  In the plasma processing apparatus 1 having such a configuration, when the second electrode 3 is rotated in one direction of the central axis, the effective electrode region 31a facing the processing surface 11 of the workpiece 10 is located from the position of the side 311 shown in FIG. It will change to the position of the vertex 314. That is, the width W of the effective electrode region 31a facing the processing surface 11 is gradually decreased or gradually increased from the width of the second electrode 3 to near zero, and continuously changes.

Here, in this embodiment, it arrange | positions so that the center of the width | variety of the processing surface 11 of the rectangular workpiece 10 and the center of the width | variety of the effective electrode area | region 31a may correspond. Furthermore, as described above, the effective electrode region 31a has an isosceles triangle in which the vertex 314 is located at the center of the width of the second electrode 3, and therefore, the width of the effective electrode region 31a facing the processing surface 11 Is located on a line segment connecting the center 315 of the side 311 and the vertex 314. Therefore, even if the second electrode 3 is rotated, the center of the width of the effective electrode region 31 a facing the processing surface 11 is not displaced in the direction of the central axis (rotation axis) of the second electrode 3. .
Therefore, as in the present embodiment, when the processing surface 11 of the workpiece 10 has a rectangular shape and the width of the processing surface 11 is constant, the second electrode 3 is rotated and then stopped at a predetermined position. Then, the second electrode 3 can be positioned so that the width W of the effective electrode region 31 a facing the processing surface 11 of the workpiece 10 corresponds to the width of the processing surface 11 of the workpiece 10.

Therefore, in the state where the width W of the effective electrode region 31 a facing the processing surface 11 of the workpiece 10 corresponds to the width of the processing surface 11 of the workpiece 10, a processing gas is supplied between the processing surface 11 and the second electrode 3. When supplied and a high frequency voltage is applied between the first electrode 2 and the second electrode 3, plasma is generated between the effective electrode region 31 a and the processing surface 11 by the action of the high frequency voltage. The plasma and radicals in the plasma react with the processing surface 11 (work 10) to generate a reaction product. Then, the reaction product is detached from the processing surface 11 by vaporization or the like, so that the workpiece 10 is etched according to the width of the processing surface 11.
That is, since the plasma is preferentially generated between the effective electrode region 31a and the processing surface 11 without generating the plasma between the non-effective electrode region 31b and the processing surface 11, the workpiece 10 is subjected to the processing. Etching is performed corresponding to the width of the surface 11.

  Then, when the workpiece 10 subjected to the etching process corresponding to the width of the processing surface 11 is moved in the X-axis direction in FIG. 1 (that is, a direction substantially perpendicular to the width direction of the workpiece 10), the processing is performed. The surface 11 is subjected to plasma processing in a rectangular shape while maintaining its width. As a result, plasma processing can be performed on the processing surface 11 in accordance with the shape of the processing surface 11 of the workpiece 10.

As described above, according to the plasma processing apparatus 1 of the present invention, the width W of the effective electrode region 31a facing the processing surface 11 can be changed with a relatively simple configuration in which the second electrode 3 is rotated. Therefore, the second electrode 3 can be positioned with respect to the workpiece 10 relatively easily according to the width of the processing surface 11 of the workpiece 10.
Moreover, since it becomes the structure which changes the width W of the effective electrode area | region 31a which faces the process surface 11 according to the width | variety of the workpiece | work 10, the 1st electrode 2 and the effective electrode area | region 31a have faced. Since there is no portion where the processing surface 11 of the workpiece 10 does not exist in the region, it is possible to reliably prevent waste of power.

As described above, the configuration of the second electrode 3 that generates plasma preferentially in the effective electrode region 31a without generating plasma in the non-effective electrode region 31b includes, for example, the following configuration. Can be mentioned.
That is, as the second electrode 3, for example, I) The effective electrode region 31 a protrudes from the non-effective electrode region 31 b, which is the other portion, on the outer peripheral surface thereof. II) that is configured such that the distance to the processing surface 11 is closer, and II) that the effective electrode region 31a is configured to have higher conductivity than the non-effective electrode region 31b on the outer peripheral surface thereof. . With the configuration of I), there is a difference between the separation distance between the effective electrode region 31a and the first electrode 2 and the separation distance between the non-effective electrode region 31b and the first electrode 2. Due to the difference, plasma is preferentially generated in the effective electrode region 31a. Further, with the configuration of II), plasma is preferentially generated in the effective electrode region 31a due to the difference in conductivity between the effective electrode region 31a and the non-effective electrode region 31b.

Specifically, the second electrode 3 having the configuration I) corresponds to a position to be an effective electrode region 31a on the outer peripheral surface of the conductive core material 316 as shown in FIG. 2A, for example. Thus, it can obtain by forming the convex part 317 which has electroconductivity.
Also, the second electrode 3 having the configuration II) corresponds to a position that becomes the ineffective electrode region 31b on the outer peripheral surface of the conductive core material 316, as shown in FIG. 2B, for example. It can be obtained by forming the convex portion 318 made of an insulating material, that is, by exposing the outer peripheral surface of the conductive core material 316 from the effective electrode region 31a.

As the constituent material of the core material 316, the same materials as those described above as the constituent material of the first electrode 2 can be used.
Further, as the constituent material of the convex portion 317, the same materials as those mentioned as the constituent material of the first electrode 2 can be used.
Furthermore, the constituent material of the convex portion 318 is not particularly limited as long as it has insulating properties, but examples thereof include ceramic (alumina), silicon dioxide, silicon nitride, polytetrafluoroethylene, polyethylene terephthalate, and polyimide. An insulating material having excellent insulating properties can be given.

  Moreover, although the height (thickness) of the convex part 317 is suitably set according to the kind of the constituent material of the convex part 317, the constituent material of the core material 316, etc., it is preferable that it is about 1-30 mm, for example. 2 to 12 mm is more preferable. By setting within this range, plasma can be reliably generated in the effective electrode region 31a without generating plasma in the non-effective electrode region 31b.

The thickness of the convex portion 318 is also appropriately set according to the constituent material of the convex portion 318 and the type of the constituent material of the core material 316. For example, the thickness is preferably about 1 to 20 mm, and about 2 to 6 mm. Is more preferable. By setting within this range, plasma can be reliably generated in the effective electrode region 31a without generating plasma in the non-effective electrode region 31b.
In addition, the core material 316 may be comprised with the hollow body, and may be comprised with the solid body.

  Further, the outer peripheral surface of the effective electrode region 31a may be covered with a dielectric layer (not shown) with a thickness within a range where plasma is preferentially generated in the effective electrode region 31a. With this configuration, it is possible to prevent a spark discharge from occurring in the second electrode 3. As a result, it is possible to prevent the plasma processing apparatus 1 from being defective due to the spark discharge.

The material constituting the dielectric layer is preferably a material having a dielectric constant as high as possible. Examples thereof include various ceramic materials such as alumina and zirconia, and various glass materials such as quartz glass and borosilicate glass. It is done.
The thickness of the dielectric layer is not particularly limited, but is preferably about 0.5 to 10 mm, and more preferably about 1 to 3 mm.

Even if the effective electrode region 31a has a shape similar to the above-mentioned isosceles triangle, the above-described operation and effect can be obtained in the same manner. Specifically, both the side 312 and the side 313 may be curved with the same radius of curvature toward the line segment connecting the center 315 and the vertex 314, or the opposite. It may be curved to the side.
In addition, it is preferable that the plasma processing apparatus 1 has a function of driving so that the separation distance between the first electrode 2 and the effective electrode region 31a approaches or separates. By providing the plasma processing apparatus 1 with such a function, the separation distance between the first electrode 2 and the effective electrode region 31a can be set to a desired size, so that regardless of the shape of the second electrode 3 or the like. Plasma can be generated preferentially between the first electrode 2 and the effective electrode region 31 a facing the processing surface 11.

Next, a method for etching the workpiece 10 using the plasma processing apparatus 1 having the above-described configuration will be described.
<1A> First, the operator inputs the width (width) of the processing surface 11 of the workpiece 10 into the operation unit 7. As a result, data such as the width of the processing surface 11 is recorded in the storage unit 8.
<2A> Next, the operator places the workpiece 10 on the workpiece setting portion 21 provided on the first electrode 2 with the processing surface 11 on the upper side, and then moves the plasma processing apparatus 1 on. Operate.

<3A> When the plasma processing apparatus 1 starts operating, the control unit 6 first operates the drive source 33 based on the width data of the workpiece 10 stored in the storage unit 8, as shown in FIG. As described above, the second electrode 3 is rotated so that the width W of the effective electrode region 31 a facing the processing surface 11 of the workpiece 10 corresponds to the width of the processing surface 11 of the workpiece 10. Then, the control means 6 stops the rotation of the second electrode 3 at a position where the width W of the effective electrode region 31 a facing the processing surface 11 corresponds to the width of the processing surface 11 of the workpiece 10.
Here, when processing a workpiece 10 ′ having a wider processing surface 11 ′ than the processing surface 11 of the workpiece 10 shown in FIG. 1, as shown in FIG. 3, the processing surface 11 ′ of the workpiece 10 ′. In order to correspond to this width, the second electrode 3 is rotated and stopped so that the width W of the effective electrode region 31a facing the processing surface 11 is increased.

<4A> Next, the control means 6 operates the high frequency power supply 41 and closes the switch 45. By the operation of the high frequency power supply 41, a high frequency voltage is applied between the first electrode 2 and the second electrode 3 (the effective electrode region 31a facing the processing surface 11), and an electric field is generated between them.
At this time, the control means 6 opens the valve 54, adjusts the gas flow rate by the regulator 53, and sends the processing gas (etching processing gas) from the gas cylinder 52.
Thereby, the processing gas sent from the gas cylinder 52 flows through the supply pipe 55 and flows out from the nozzle 51 opened at a corresponding position between the processing surface 11 of the workpiece 10 and the second electrode 3 at a predetermined flow rate. (Squirt). As a result, the processing gas is introduced (supplied) between the second electrode 3 and the workpiece 10, and plasma is generated by being activated by the discharge.

This plasma is generated between a portion where an electric field is generated, that is, an effective electrode region 31 a facing the processing surface 11 and the workpiece 10. The generated plasma (activated processing gas) comes into contact with the processing surface 11 located in a region facing the effective electrode region 31a, and the processing surface 11 is etched.
At this time, the supply amount of the processing gas is adjusted by the regulator 53 in accordance with the width of the effective electrode region 31a facing the processing surface of the workpiece. That is, as shown in FIG. 1, the regulator 53 sets the supply amount of the processing gas to be small when the width W of the effective electrode region 31a is smaller than that shown in FIG. In this way, by adopting a configuration in which the supply amount of the processing gas is adjusted (changed) according to the width of the effective electrode region 31a, the processing surface 11 and the effective electrode region can be supplied without supplying an excessive amount of the processing gas. Plasma can be reliably generated between 31a. As a result, it is possible to reduce the amount of processing gas that is wasted.

<5A> Next, the control means 6 moves the 1st electrode 2 to the X-axis direction in FIG. 1 by operating a conveyance means. As a result, the workpiece 10 placed on the first electrode 2 also moves in the X-axis direction, that is, in a direction substantially perpendicular to the width direction of the workpiece 10. As a result, in the step <4A>, the plasma generated between the processing surface 11 and the effective electrode region 31a causes the width W of the effective electrode region 31a, that is, the width of the processing surface 11 toward the X-axis direction sequentially. The processing surface 11 is etched by plasma. As described above, by adopting a configuration in which the workpiece 10 is moved by the conveying means, it is possible to perform plasma processing over the entire processing surface 11.
<6A> Next, when the plasma processing is performed on the entire processing surface 11, the control unit 6 stops the operations of the transport unit, the power supply circuit 4, and the gas supply unit 5. Thereafter, the operator removes the workpiece 10 from the workpiece installation unit 21.
Through the steps as described above, the processing surface 11 of the workpiece 10 is etched.

According to the plasma processing apparatus 1, the width W of the effective electrode region 31 a facing the processing surface 11 can be changed with a relatively simple configuration in which the second electrode 3 is rotated. The second electrode 3 can be relatively easily aligned with the width of the processing surface 11 of the workpiece 10.
Moreover, since it becomes the structure which changes the width W of the effective electrode area | region 31a which faces the process surface 11 according to the width | variety of the workpiece | work 10, the 1st electrode 2 and the effective electrode area | region 31a have faced. Since there is no portion where the processing surface 11 of the workpiece 10 does not exist in the region, it is possible to reliably prevent waste of power.
In the present embodiment, the case where almost the entire surface of the workpiece 10 is configured by the processing surface 11 has been described. However, the present invention is not limited to such a case. 11 may be used. Even with the workpiece 10 having such a configuration, the plasma processing can be performed on the processing surface 11 in the same manner as described above.

<Second Embodiment>
Next, a second embodiment of the plasma processing apparatus of the present invention will be described.
FIG. 4 is a perspective view (including a partial block diagram) schematically showing a second embodiment of the plasma processing apparatus of the present invention. In the following description, the upper side in FIG. 4 is referred to as “upper” and the lower side is referred to as “lower”.

Hereinafter, although the second embodiment will be described, the description will focus on the differences from the first embodiment, and the description of the same matters will be omitted.
The plasma processing apparatus of this embodiment is substantially the same as that of the first embodiment except that the second electrode 3 performs a different operation due to the circular shape of the workpiece to be processed.
In the present embodiment, instead of the rectangular workpiece 10, a circular workpiece 10 ″ is placed on the workpiece installation unit 21. Hereinafter, the entire upper surface of the circular workpiece 10 ″, that is, a circle, is mounted. A method of etching the processed surface 11 '' having the shape using the plasma processing apparatus 1 will be described.

<1B> First, the operator inputs, for example, the size of the radius of the processing surface 11 ″ of the workpiece 10 ″ to the operation unit 7. Thereby, data such as the radius of the processing surface 11 ″ is recorded in the storage means 8.
<2B> Next, the operator places the workpiece 10 ″ on the workpiece installation portion 21 provided on the first electrode 2 with the processing surface 11 ″ on the upper side, and then plasma. The processing device 1 is activated.

<3B> When the plasma processing apparatus 1 starts to operate, the control unit 6 first operates the transfer unit, so that the workpiece 10 ″ reaches a position where one end of the processing surface 11 ″ faces the effective electrode region 31a. After moving, stop. Then, the control means 6 operates the drive source 33 so that the vertex 314 faces the position where the width W of the effective electrode region 31a facing the processing surface 11 ″ is near zero, that is, the processing surface 11 ″. At the position, the rotation of the second electrode 3 is stopped.
<4B> Next, the control means 6 operates the power supply circuit 4 and the gas supply unit 5 in the same manner as in the above step <4A> to generate plasma between the apex 314 and the processing surface 11 ''. generate. As a result, one end of the processing surface 11 ″ facing the vertex 314 is etched.

<5B> Next, the control means 6 moves the 1st electrode 2 to the X-axis direction in FIG. 4 by operating a conveyance means. As a result, the workpiece 10 ″ placed on the first electrode 2 also moves in the X-axis direction, that is, in a direction substantially perpendicular to the width direction of the workpiece 10 ″.
Along with this movement, the width of the processing surface 11 facing the second electrode 3 (effective electrode region 31a) is such that the width of the processing surface 11 after facing one end of the processing surface 11 ″ is the diameter. Until it coincides with the diameter, and gradually decreases until the width of the width coincides with the other end.
Therefore, in order to perform plasma processing on the entire surface of the processing surface 11 ″ despite the change of the width of the processing surface 11 ″ facing the effective electrode region 31a, the width of the processing surface 11 ″ is gradually increased or decreased. Accordingly, it is necessary to gradually increase or decrease the width of the effective electrode region 31a so as to correspond to this.

  Therefore, in the plasma generating apparatus 1 of the present embodiment, the control means 6 operates the drive source 33 so that the effective electrode region 31a faces one end of the processing surface 11 ″ and then the processing surface 11 ′ that faces the processing surface 11 ′. Until the width of the second electrode 3 coincides with the diameter of the second electrode 3 in the direction indicated by the arrow A in FIG. 4 so that the width W of the effective electrode region 31a facing the processing surface 11 ″ gradually increases. Is configured to rotate. The control means 6 then treats the processing surface 11 from the time when the width of the processing surface 11 ′ facing the effective electrode region 31a coincides with the diameter until it faces the other end of the processing surface 11 ″. The second electrode 3 is configured to rotate in the direction indicated by the arrow B in FIG. 4 so that the width W of the effective electrode region 31a facing ″ gradually decreases. That is, the control unit 6 is configured to rotate the second electrode 3 so that the width W of the effective electrode region 31a corresponds to the width of the processing surface 11 '' of the workpiece 10 ''.

  With such a configuration, plasma generated between the processing surface 11 ″ and the effective electrode region 31 a is generated corresponding to the width of the processing surface 11 ″. As a result, the processing surface 11 '' can be sequentially etched by plasma in the X-axis direction with the width W of the effective electrode region 31a, that is, the width of the processing surface 11 '', so that the entire processing surface 11 '' can be etched. Plasma treatment can be performed over the entire area.

By the way, when it is set as the structure from which the magnitude | size of the width W of the effective electrode area | region 31a which faces process surface 11 'changes like this embodiment, the 1st electrode 2 and the 2nd electrode 3 (effective electrode area | region 31a). The magnitude of the power density between and changes. When the plasma processing is performed on the surface 11 ″ to be processed in such a state where the power density is changed, unevenness occurs in the etching of the processing surface 11 ″.
Therefore, when the power density between the first electrode 2 and the second electrode 3 changes, it is preferable to reduce the power density. Thereby, it is possible to suppress a difference in the etching rate of the processing surface 11 ″, and as a result, unevenness in etching (processing) of the processing surface 11 ″ is reduced.

  The method for reducing the change in the magnitude of the power density is not particularly limited. For example, a method of adjusting the relative movement speed of the workpiece 10 with respect to the second electrode 3 can be mentioned. Specifically, in the present embodiment, the effective electrode region 31a faces one end portion of the processing surface 11 ″ until the width of the facing processing surface 11 ′ matches the diameter. In addition, when the width W of the effective electrode region 31a facing the processing surface 11 ″ is gradually increased, the moving speed of the workpiece 10 is reduced. Then, the processing surface 11 '' is from the time when the width of the processing surface 11 'facing the effective electrode region 31a coincides with the diameter until it faces the other end of the processing surface 11' '. When the width W of the effective electrode region 31a facing the surface gradually decreases, the moving speed of the workpiece 10 may be accelerated.

  In addition, as a method of reducing the change in the magnitude of the power density, for example, a method of adjusting the magnitude of the power applied between the first electrode 2 and the second electrode 3 by the power supply circuit 4 can be given. It is done. Specifically, in the present embodiment, the effective electrode region 31a faces one end portion of the processing surface 11 ″ until the width of the facing processing surface 11 ′ matches the diameter. In addition, when the width W of the effective electrode region 31a facing the processing surface 11 ″ is gradually increased, the magnitude of the power applied by the high frequency power supply 41 is increased. Then, the processing surface 11 '' is from the time when the width of the processing surface 11 'facing the effective electrode region 31a coincides with the diameter until it faces the other end of the processing surface 11' '. When the width W of the effective electrode region 31a facing the electrode gradually decreases, the power applied by the high-frequency power source 41 may be configured to gradually decrease.

  <6B> Next, when the plasma processing is performed on the entire processing surface 11 ″, the control unit 6 stops the operations of the transport unit, the power supply circuit 4, and the gas supply unit 5. Thereafter, the operator removes the workpiece 10 ″ from the workpiece setting unit 21.

Through the steps as described above, the processing surface 11 '' of the circular workpiece 10 '' is etched.
With the configuration as described above, the plasma processing apparatus 1 of the present embodiment can perform plasma processing on the circular processing surface 11 '', and the plasma processing apparatus 1 of the first embodiment Similar actions and effects can be obtained.
In the present embodiment, the case where the shape of the effective electrode region 31a is an isosceles triangle has been described. However, in addition to such a case, the effective electrode region 31a is formed so as to correspond to the shape of the processing surface 11 '' of the workpiece 10 ''. May be. In the case of such a configuration, by performing the movement of the workpiece 10 ″ and the rotation of the second electrode 3 so that the respective shapes correspond to each other, it is possible to perform plasma processing on the entire processing surface 11 ″. The operations and effects as described above can be obtained in the same manner.
As mentioned above, although the plasma processing apparatus of this invention was demonstrated based on embodiment of illustration, this invention is not limited to this, Each part which comprises a plasma processing apparatus can exhibit the same function. Any configuration can be substituted, or any configuration can be added.

1 is a perspective view schematically showing a first embodiment of a plasma processing apparatus of the present invention. It is a perspective view which shows the structure of the 2nd electrode with which the plasma processing apparatus shown in FIG. 1 is provided. It is a perspective view which shows typically the case where a wide workpiece | work is processed with the plasma processing apparatus of 1st Embodiment. It is a perspective view which shows typically 2nd Embodiment of the plasma processing apparatus of this invention. It is a figure which shows typically the positional relationship of the workpiece | work and electrode at the time of processing a workpiece | work with the conventional plasma processing apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Plasma processing apparatus 2 ... 1st electrode 21 ... Work installation part 3 ... 2nd electrode 31a ... Effective electrode area | region 31b ... Ineffective electrode area | region 311, 312, 313 ... Side 314 ... Vertex 315... Center 316... Core material 317, 318... Projection 32... Rotating shaft 33... Drive source 4 ... Power supply circuit 41 ... High-frequency power supply 42 and 43 ... Wiring 44. ...... Switch 5 ...... Gas supply part 51 ...... Nozzle 52 ...... Gas cylinder 53 ...... Regulator 54 ...... Valve 55 ...... Supply pipe 6 ...... Control means 7 ...... Operating part 8 ...... Storage means 10, 10 ′, 10 "... Work 11, 11 ', 11" ... Processing surface 102 ... 1st electrode 103 ... 2nd electrode 110, 110' ... Work W ... Width

Claims (13)

A work installation section for installing the work;
A first electrode;
It is located on the side opposite to the first electrode of the workpiece installation section, and is installed so that the outer peripheral surface faces the processing surface of the workpiece installed in the workpiece installation section, and is rotatable about the central axis as a rotation axis A cylindrical second electrode;
Gas supply means for supplying a processing gas for generating plasma in a gap between the second electrode and the workpiece;
A power supply circuit having a power supply for applying a high frequency voltage between the first electrode and the second electrode so that the processing gas supplied to the gap is turned into plasma,
A plasma processing apparatus for processing a processing surface of the workpiece with generated plasma,
The second electrode has a portion in which the width of the effective electrode region is changed along the circumferential direction on the outer peripheral surface,
A plasma processing apparatus configured to change the width of the effective electrode region facing the processing surface of the workpiece by rotating the central axis of the second electrode as a rotation axis.   2. The plasma according to claim 1, wherein the second electrode is configured such that a width of the effective electrode region facing the processing surface of the workpiece gradually decreases or gradually increases as the central axis rotates in one direction. Processing equipment.   The center of the width | variety of the said effective electrode area | region which faces the process surface of the said workpiece | work when the said 2nd electrode rotates is not displaced to the rotation axis direction of the said 2nd electrode. Plasma processing equipment.   The plasma processing apparatus according to claim 3, wherein the second electrode has a center of a width of the effective electrode region facing a processing surface of the workpiece corresponding to a center of a width of the processing surface of the workpiece.   The said 2nd electrode is comprised so that the distance with respect to the said processing surface may become near, when the said effective electrode area | region protrudes with respect to parts other than the said effective electrode area | region in the said outer peripheral surface. The plasma processing apparatus according to any one of the above.   6. The plasma processing apparatus according to claim 1, wherein the second electrode is configured such that, on the outer peripheral surface, the effective electrode region has higher conductivity than a portion other than the effective electrode region. .   The plasma processing apparatus according to claim 1, further comprising a control unit that controls rotation of the second electrode.   The said control means controls rotation of the said 2nd electrode so that the width | variety of the said effective electrode area | region which faces the process surface of the said workpiece | work corresponds to the width | variety of the process surface of the said workpiece | work. Plasma processing equipment. When processing the workpiece, the width of the processing surface of the workpiece changes relative to the second electrode,
While the second electrode is rotated by the control means, the width of the effective electrode area facing the processing surface of the workpiece is made to correspond to the width of the processing surface of the workpiece, and the processing surface of the workpiece is processed. The plasma processing apparatus according to claim 8.   To alleviate the change in the power density between the first electrode and the second electrode, which is caused by the change in the width of the effective electrode region facing the processing surface of the workpiece. Furthermore, the plasma processing apparatus of Claim 9 which adjusts the relative moving speed with respect to the said 2nd electrode of the said workpiece | work.   To alleviate the change in the power density between the first electrode and the second electrode, which is caused by the change in the width of the effective electrode region facing the processing surface of the workpiece. Furthermore, the magnitude | size of the electric power applied between the said 1st electrode and the said 2nd electrode by the said power supply circuit is adjusted.   The plasma processing apparatus according to claim 1, wherein the gas supply unit includes a gas adjustment unit that can vary a supply amount of a processing gas supplied per unit time.   The plasma processing apparatus according to claim 12, wherein the gas adjusting unit changes a supply amount of the processing gas according to a width of the effective electrode region facing the processing surface of the workpiece.

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