JP2010087049A - Plasma processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing apparatus that accurately positions a work on a mounting surface of a mounting portion, easily removes the work from the mounting portion after plasma processing, and prevents the work from being broken and the mounting surface from being damaged. <P>SOLUTION: The plasma processing apparatus 1 has a lower electrode 22 having the mounting surface 221 and the lower electrode is provided with a pin (projection) 61 capable of freely projecting from the mounting surface 221, the pin 61 moving into a projection state wherein its tip surface 611 projects from the mounting surface 221 or into a storage state wherein the tip surface 611 is matched in level with the mounting surface 221. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus.

As one method of processing the surface of a material, a processing gas containing a reactive gas is supplied between electrodes to which a high-frequency voltage is applied, a radical based on the reactive gas is generated, and generated by a radical reaction between the radical and the workpiece. A so-called plasma chemical machining (hereinafter, abbreviated as “plasma CVM”) is known in which processing is performed by removing the generated product.
In such a plasma CVM, a method is known in which plasma is generated by applying a high frequency between a pair of electrodes in a state where the workpiece is positioned on a mounting table provided between the pair of electrodes, and the workpiece is plasma-treated. It has been. In this processing method, after the workpiece is placed on the mounting table, the plasma processing is performed after performing precise positioning using the positioning mechanism.

The positioning mechanism described in Patent Literature 1 is open to the stage 1 including an indication surface 1c that supports the workpiece W, a plurality of pins 1e that are provided on the indication surface 1c and that position the workpiece W, and the indication surface 1c. And a plurality of ejection holes 1d for ejecting gas to the workpiece W.
In such a positioning mechanism described in Patent Document 1, since the workpiece W can be positioned using a plurality of pins 1e, the workpiece W can be accurately placed at a predetermined position.

However, in the positioning mechanism described in Patent Document 1, the plasma state in the region corresponding to the ejection hole 1d on the surface to be processed of the workpiece W (the region where the metal as an electrode does not exist immediately below) and the other regions (the electrode directly below) As a result, the plasma state in the region where the metal exists is different. Further, the plasma state in the region near the pin 1e on the surface to be processed of the workpiece W is different from the plasma state in other regions.
Therefore, the positioning mechanism described in Patent Document 1 cannot perform stable plasma processing on the entire surface of the workpiece W to be processed.

JP 2004-31799 A

  The object of the present invention is to accurately position the workpiece on the mounting surface of the mounting portion, and at the time of plasma processing, stable plasma processing can be performed on the entire surface of the workpiece to be processed. It is an object of the present invention to provide a plasma processing apparatus that can easily remove a workpiece from the mounting portion after the plasma processing and can prevent breakage of the workpiece and damage of the mounting surface.

Such an object is achieved by the present invention described below.
The plasma processing apparatus of the present invention comprises an upper electrode and a lower electrode arranged to face each other,
A mounting portion including a mounting surface for mounting the workpiece so that a workpiece having a processing surface is positioned between the upper electrode and the lower electrode;
Protrusions provided on the mounting portion, and protruding and retracting from the mounting surface,
A processing gas supply means for supplying a processing gas to the surface to be processed;
Energization means for energizing between the upper electrode and the lower electrode,
The protrusion is characterized in that the tip surface thereof moves between a protruding state in which it protrudes from the mounting surface and a housing state that matches the mounting surface.

  As a result, the workpiece can be accurately positioned on the mounting surface of the mounting portion, and at the time of plasma processing, stable plasma processing can be performed on the entire surface to be processed of the workpiece. After the processing, it is possible to provide a plasma processing apparatus that can easily remove the workpiece from the mounting portion and prevent the workpiece from being damaged and the mounting surface from being damaged.

In the plasma processing apparatus of the present invention, it is preferable that the projection has a function as a positioning projection for positioning the workpiece by bringing the workpiece into contact with a side surface in the protruding state.
As a result, the workpiece can be accurately positioned.
In the plasma processing apparatus of the present invention, the protrusion is moved from the accommodation state to the protruding state in a state where the workpiece is placed on the placement surface, so that the lower surface of the workpiece is at the tip thereof. It is preferable to have a function as a separation protrusion that separates the pressed portion of the workpiece from the placement surface.
Thereby, a workpiece | work can be lifted from a mounting surface, and removal of a workpiece | work becomes easy. Further, sliding between the workpiece and the mounting surface is prevented, and damage to the workpiece, damage to the mounting surface (generation of scratches), and the like can be prevented.

In the plasma processing apparatus of the present invention, a plurality of the protrusions are provided,
A plurality of the protrusions, in the protruding state, in a state where the workpiece is placed on the placement surface, and a positioning protrusion that positions the workpiece by contacting the workpiece to the side surface thereof, A separation protrusion for pressing the lower surface of the workpiece at the tip thereof and moving the pressed portion of the workpiece away from the placement surface by moving from the accommodated state to the protruding state; Preferably it is.
Accordingly, the workpiece can be accurately positioned, and the workpiece can be easily removed by lifting the workpiece from the placement surface. Further, when the workpiece is removed, sliding between the workpiece and the mounting surface is prevented, and damage to the workpiece, damage to the mounting surface (generation of scratches), and the like can be prevented.

In the plasma processing apparatus of the present invention, it is preferable that each of the protrusions functions as both a positioning protrusion and a separation protrusion.
Thereby, it is possible to select whether each protrusion functions as a positioning protrusion or as a separation protrusion for each protrusion. Therefore, it is possible to have more patterns of which projections function as positioning projections and which projections function as separation projections among a plurality of projections, regardless of the size, shape, etc. of the workpiece, The workpiece can be positioned and removed easily and accurately.

In the plasma processing apparatus of the present invention, it is preferable that the plasma processing of the workpiece is performed with the protrusions in the accommodated state.
Thereby, since the whole area of the surface to be processed of the workpiece can be processed with plasma in a desired state, a uniform and stable plasma processing can be performed on the entire area of the surface to be processed.
In the plasma processing apparatus of the present invention, it is preferable that the protrusion has the same dielectric constant as that of the mounting portion.
As a result, the entire area of the workpiece surface to be processed can be plasma-processed by stable plasma.

Hereinafter, a plasma processing apparatus of the present invention will be described in detail based on embodiments shown in the accompanying drawings.
1 is a diagram (cross-sectional view, side view, block diagram) showing a preferred embodiment of the plasma processing apparatus of the present invention, FIG. 2 is a perspective view of a lower electrode provided in the plasma processing apparatus shown in FIG. 2 is a cross-sectional view for explaining the movement when the pin shown in FIG. 2 functions as a positioning pin, FIG. 4 is a cross-sectional view for explaining the movement when the pin shown in FIG. 2 functions as a floating pin, and FIG. It is the top view which simulated the condition where the workpiece | work 10 was mounted in the mounting surface. In the following description, three directions orthogonal to each other in FIG. 1 are defined as an x-axis direction, a y-axis direction, and a z-axis direction. Among these, the processing target surface 101 of the workpiece 10 is an xy plane, and the normal direction of the processing target surface 101 is a z-axis direction. Hereinafter, the corresponding directions are the same in other drawings. Further, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

The plasma processing apparatus 1 shown in FIG. 1 includes an upper electrode 21 and a lower electrode 22 that are arranged to face each other, a processing gas supply means 3, an energizing means 4, a moving means 5, a positioning / separating means 6, and a control means 7. And have.
In the plasma processing apparatus 1, the processing surface of the workpiece 10 (effective processing area of the workpiece 10) is processed by the processing gas supply unit 3 with the workpiece (wafer) 10 mounted on the upper surface (mounting surface) 221 of the lower electrode 22. ) While supplying the processing gas to 101, the energizing means 4 energizes between the upper electrode 21 and the lower electrode 22 to activate the processing gas to generate plasma, and the plasma generation region S ( This is an apparatus for subjecting the surface to be treated 101 to plasma treatment locally and continuously by the plasma by moving the workpiece 10 relative to the area 10 immediately below the upper electrode 21 by the moving means 5.

In the present specification, “local” means that the plasma generation region S is sufficiently smaller than the entire surface to be processed 101 in plan view of the workpiece 10, and at least one of the upper electrode 21 and the workpiece 10 is set to the other. It means that the plasma treatment of the entire surface 101 to be treated cannot be performed unless it is relatively moved.
In addition, the term “continuous” in the present specification means not only the case where plasma is constantly generated in the plasma generation region S from the start to the end of the plasma processing for one workpiece 10, but also the plasma processing. There is a case in which no plasma is generated in the plasma generation region S from the start to the end, but there is a state (standby state) that can be generated at any time if it is to be generated.

  In addition, “plasma treatment” in the specification of the present application includes planarization processing, convex processing, bevel processing, etching processing for forming a hole penetrating or recessed in the thickness direction, a desired planar view shape, and the like. Etching process (molding process) for removing unnecessary portions, surface modification for imparting desired characteristics to the surface 101 (for example, water repellency, imparting hydrophilicity, modification by heat treatment, oxide film, etc. Formation), and general processing using plasma, such as ashing processing for removing a resist layer or the like formed on the surface 101 to be processed. Hereinafter, for the convenience of explanation, the planarization processing of the processing target surface 101 will be described as a representative.

  Also, the workpiece (wafer) 10 is not particularly limited, and examples thereof include various glasses such as quartz glass and alkali-free glass, crystalline materials such as quartz, various ceramics such as alumina, silica, and titania, silicon, gallium arsenide. Consists of dielectric materials such as various semiconductor materials such as diamond, carbon-based materials such as diamond, graphite, polyethylene, polystyrene, polycarbonate, polyethylene terephthalate, liquid crystal polymer, phenolic resin, acrylic resin, etc. Is mentioned.

As shown in FIG. 1, a lower electrode 22 is provided on an NC stage (first moving means 51 to be described later), and an upper electrode 21 is provided above the lower electrode 22.
The upper electrode 21 has a columnar shape such as a columnar shape or a quadrangular prism shape. The upper electrode 21 is connected to a high-frequency power source 41 (described later) via a conducting wire 42. Note that the shape of the upper electrode 21 can be appropriately set according to the shape of the workpiece 10 and the like, and may be, for example, a truncated cone, a quadrangular prism, or a flat plate.

Although it does not specifically limit as a constituent material of the upper electrode 21, For example, various metals, such as iron, nickel, copper, silver, or the alloy or intermetallic compound containing at least 1 sort (s) of these, Furthermore, these metals Oxides, nitrides, carbides, and the like. Among these, examples of the alloy include stainless steel, brass, and aluminum-based alloy.
The upper electrode 21 as described above is covered with a dielectric portion 24 having a lower portion made of a dielectric material.

  The dielectric portion 24 has a quadrangular prism shape. A concave portion 241 opening on the upper surface is formed, and the lower portion of the upper electrode 21 is inserted into the concave portion 241. Thus, during the plasma processing, the metal or the like that is an electrode is not exposed between the upper electrode 21 and the lower electrode 22, so that an electric field can be uniformly generated between the upper electrode 21 and the lower electrode 22. Further, since the upper electrode 21 is covered with the dielectric portion 24, an increase in impedance can be prevented, and a desired discharge can be generated at a relatively low voltage, and plasma can be generated reliably. The shape of the dielectric portion 24 is not particularly limited, for example, a truncated cone, a columnar shape, a plate shape, or the like.

  Examples of the constituent material of the dielectric portion 24 include various plastics such as polytetrafluoroethylene and polyethylene terephthalate, crystalline materials such as quartz, various glasses such as quartz glass and alkali-free glass, and inorganic oxides. Can be mentioned. Examples of the inorganic oxide include oxide ceramics such as alumina, silica, titania, and zirconia, nitride ceramics such as silicon nitride, aluminum nitride, and titanium nitride, barium titanate, strontium titanate, PZT, PLZT, and PLLZT. And other ferroelectric materials.

The lower electrode 22 is provided on the NC stage as described above, and is disposed opposite to the upper electrode 21. In the present embodiment, the lower electrode 22 is a flat plate having a rectangular shape in plan view, but the shape of the lower electrode 22 is not particularly limited. For example, even if the shape in plan view is square, circular, or the like. Good.
The upper surface 221 of the lower electrode 22 constitutes a placement surface on which the workpiece 10 is placed (hereinafter also referred to as “placement surface 221”). In other words, the lower electrode 22 has a function as a placement portion on which the workpiece is placed. In addition, the lower electrode 22 is directly grounded via the lead wire 42 and has a function as a ground electrode. Thereby, charging of the lower electrode 22 can be prevented, and an electric field can be reliably generated between the upper electrode 21 and the lower electrode 22.

As the constituent material of the lower electrode 22, the same materials as those exemplified as the constituent material of the upper electrode 21 can be used.
As shown in FIG. 2, the lower electrode 22 is formed with a plurality of holes 222 that open to the mounting surface 221 and extend in the z-axis direction. The plurality of holes 222 are formed in a grid pattern, that is, regularly. As the plurality of holes 222 are regularly formed (that is, a plurality of pins 61 to be described later are regularly arranged), the shape in plan view is a square shape, a circular shape, or an irregular shape. Even a workpiece 10 having a simple shape (planar shape) can be easily positioned and removed.

In the present embodiment, the internal space of each hole 222 has a cylindrical shape, but may have a quadrangular prism shape, a triangular prism shape, or an elliptical shape.
A pin (projection) 61 is inserted into each of the plurality of holes 222. Thus, by inserting the pin 61 into each hole 222, the pin 61 can be displaced (protrusable) with respect to the lower electrode 22 with a simple configuration.

  The pitch p between adjacent holes 222 (that is, the pitch between adjacent pins 61) p is not particularly limited, but is preferably about 5 to 30 mm, and more preferably about 10 to 25 mm. By setting the pitch p in such a range, the number of pins 61 can be relatively reduced, and the pins 61 that come into contact with the side surfaces of the workpiece 10 can be relatively positioned when positioning the workpiece 10 as described later. Many numbers can be secured.

Such a pin 61 constitutes the positioning / separating means 6 together with the pin moving means 62 for moving the pin 61 and the pin moving means control device 63. Hereinafter, the positioning / separating means 6 will be described.
First, the pins 61 inserted into the holes 222 will be described. Since each of the plurality of pins 61 has the same configuration, only one pin 61 will be described as a representative, and the other pins 61 will be described as follows. Description is omitted.

  The pin 61 has a solid cylindrical shape. The tip surface 611 of the pin 61 is a flat surface that is orthogonal to the axial direction of the pin 61. Such a pin 61 has a diameter equal to or slightly smaller than the diameter of the hole 222, and is inserted into the hole 222 without a gap. That is, the pin 61 is inserted into the hole 222 so that a gap is not substantially formed between the outer peripheral surface of the pin 61 and the inner peripheral surface of the hole 222.

  Although it does not specifically limit as a diameter of the pin 61, It is preferable that it is about 1-15 mm, and it is more preferable that it is about 5-10 mm. By setting the diameter of the pin 61 in such a range, the mechanical strength of the pin 61 can be sufficient to achieve the function of the pin 61, and the workpiece 10 is placed on the mounting surface 221. An appropriate number of pins 61 can be arranged on the lower electrode 22 for positioning.

Further, the pin 61 is slidable (movable and displaced) with respect to the hole 222, and the tip end surface of the pin 61 is slid with the inner peripheral surface of the hole 222 by driving the pin moving means 62. 611 moves from the mounting surface 221 to a protruding state, and the distal end surface 611 moves to an accommodation state in which the mounting surface 221 matches (is flush with) the mounting surface 221.
Such a pin 61 functions as a positioning pin (positioning protrusion) for accurately positioning the mounting position of the workpiece 10 with respect to the mounting surface 221 and mounts the workpiece 10 mounted on the mounting surface 221. It has both functions of a function as a floating pin (separation protrusion) that floats (separates) from the mounting surface 221. Whether the pin 61 functions as a positioning pin or a floating pin is appropriately determined depending on the shape, size, mounting position, and the like of the workpiece mounted on the mounting surface 221.

Although all the pins 61 preferably have both functions as positioning pins and floating pins, some of the pins 61 function as positioning pins and floating pins. Only one of the functions may be provided.
When the pin 61 functions as a positioning pin, the pin 61 moves as follows.
First, as shown in FIG. 3A, the pin 61 moves to a protruding state in which the tip surface 611 protrudes from the mounting surface 221 by driving the pin moving means 62. In this state, the workpiece 10 is placed on the placement surface 221. At this time, the workpiece 10 is brought into contact with the side surface of the pin 61 as shown in FIG. Positioning with respect to the ten placement surfaces 221 is performed. Thereby, the workpiece | work 10 can be positioned easily and reliably.

  After the positioning is completed, as shown in FIG. 3C, the tip end surface 611 is moved to the accommodation state in which the mounting surface 221 coincides with the driving of the pin moving means 62. The plasma treatment is performed. As described above, when the pins 61 functioning as positioning pins are placed in the accommodated state during the plasma processing, the entire processing target surface 101 of the workpiece 10 can be subjected to plasma processing with stable plasma.

  Specifically, although it depends on the protrusion amount of the pin 61, the strength of the applied voltage (RF power), etc., the plasma processing of the workpiece 10 is performed while the pin 61 functioning as a positioning pin is left in the protruding state. Then, unstable plasma is generated between the pin 61 and the upper electrode 21, and the portion around the pin 61 in the protruding state of the processing target surface 101 is subjected to plasma processing by the unstable plasma. It will be. Therefore, uniform and stable plasma processing cannot be performed on the entire surface 101 to be processed.

  Note that the length of the pin 61 in the protruding state (the length of the protruding portion in the z-axis direction) is preferably longer than the thickness of the workpiece 10. More specifically, when the thickness of the workpiece 10 is d, the length of the pin 61 is preferably about 2d to 4d. As a result, when the workpiece 10 is placed on the placement surface 221, the workpiece 10 can be accurately brought into contact with the side surface of the pin 61.

On the other hand, when the pin 61 functions as a floating pin, the pin 61 moves as follows.
For example, when the plasma processing on the workpiece 10 is completed and the workpiece 10 is removed from the placement surface 221, the area of the lower surface of the workpiece 10 is driven by driving the pin moving means 62 as shown in FIGS. 4 (a) and 4 (b). The pin 61 contained therein is moved from the accommodated state to the protruding state. Then, the front end surface 611 of the pin 61 presses the lower surface of the work 10, and the lower surface of the work 10 is lifted (separated) from the placement surface 221 as shown in FIG. In this state, as shown in FIG. 4C, by removing the workpiece 10 from the placement surface 221, the workpiece 10 can be easily removed, and no unnecessary force (stress) is generated in the workpiece 10. The work 10 is prevented from being damaged. Further, since most of the workpiece 10 is separated from the placement surface 221, damage (occurrence of scratches or the like) of the placement surface 221 due to sliding friction with the workpiece 10 is prevented.

Such a pin 61 preferably has the same dielectric constant as that of the lower electrode 22. Thereby, since the electrical characteristics are the same in the entire region of the lower electrode 22 including the pin 61, the entire region of the surface to be processed 101 of the workpiece 10 can be plasma-processed by stable plasma.
Specifically, when the dielectric constant of the pin 61 is different from the dielectric constant of the lower electrode 22, an area corresponding to the pin 61 on the surface 101 to be processed (an area where the pin 61 exists immediately below) and an area other than that area. Although the plasma processing may be uneven in the region where the mounting surface 221 of the lower electrode 22 is present immediately below, if the dielectric constant of the pin 61 is the same as the dielectric constant of the lower electrode 22, Since both the region corresponding to the pin 61 of 101 and the other region can be subjected to plasma processing with desired plasma, uniform and stable plasma processing over the entire surface 101 (desired) Plasma treatment) can be performed.

The constituent material of the pin 61 is not particularly limited, but is preferably the same constituent material as the constituent material of the lower electrode 22. Thereby, the dielectric constant of the pin 61 can be easily made the same as the dielectric constant of the lower electrode 22.
The pin moving means 62 is not particularly limited as long as the pin 61 can be moved between the protruding state and the accommodated state. For example, the pin moving means 62 may include a solenoid whose movable core is connected to the pin 61, and may be configured to move the pin 61 between the protruding state and the accommodated state by changing the movable core by driving the solenoid. Good. According to such a configuration, the pin 61 can be moved with a relatively simple configuration.

  The pin moving means 62 has a plurality of solenoids (as many as the number of pins 61) provided so as to correspond to the respective pins 61, and the pin moving means control device 63 causes the plurality of solenoids to be set. Each can be driven independently. Since the plurality of solenoids can be driven independently, it is possible to select whether the plurality of pins 61 function as positioning pins or floating pins, respectively. For this reason, it is possible to have more patterns of which pins 61 of the plurality of pins 61 function as positioning pins and which pins 61 function as floating pins, depending on the size, shape, and the like of the workpiece 10. In addition, the workpiece 10 can be positioned and removed easily and accurately.

  The processing gas supply means 3 is directed to a gas cylinder (gas supply source) 31 filled with a predetermined gas, a mass flow controller (flow rate adjustment means) 32 for adjusting the flow rate of the gas supplied from the gas cylinder 31, and the plasma generation region S. A nozzle 33 that ejects the processing gas, a processing gas supply channel 34 that connects the nozzle 33 and the gas cylinder 31, and a valve that opens and closes the channel in the processing gas supply channel 34 on the downstream end side from the mass flow controller 32. (Electromagnetic valve) 35. The mass flow controller 32 and the valve 35 are electrically connected to the control means 7, respectively, and their operation is controlled by the control means 7.

  Such a processing gas supply means 3 sends out the processing gas from the gas cylinder 31 with the valve 35 opened, and adjusts the flow rate of the processing gas by the mass flow controller 32. Then, the processing gas whose flow rate is adjusted is introduced (supplied) from the nozzle 33 to the plasma generation region S via the processing gas supply channel 34. Further, the processing gas supply means 3 stops the supply of the processing gas to the plasma generation region S by closing the valve 35.

Examples of the processing gas filled in the gas cylinder 31 include fluorine atom-containing compound gases such as CF ₄ , C ₂ F ₆ , C ₃ F ₆ , C ₄ F ₈ , CClF ₃ , SF ₆ , Cl ₂ , BCl ₃ , Various halogen-based gases such as a chlorine atom-containing compound gas such as CCl ₄ are used.
Further, as the processing gas, a mixed gas composed of the processing gas and the carrier gas is generally used. The “carrier gas” refers to a gas introduced for starting discharge and maintaining discharge.

In this case, the gas cylinder 31 may be filled with a mixed gas (processing gas + carrier gas), or the processing gas and the carrier gas may be filled in different gas cylinders, and the middle of the processing gas supply channel 34. A configuration in which these are mixed at a predetermined mixing ratio may be employed.
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. Further, O ₂ may be mixed with the mixed gas in order to promote dissociation of the processing gas.

  The nozzle 33 is installed so that the tip portion thereof faces the plasma generation region S. As a result, the processing gas can be smoothly supplied to the surface to be processed 101. The shape, arrangement position, number, and the like of the nozzle 33 are not particularly limited as long as the processing gas can be supplied to the processing target surface 101. For example, the nozzle 33 may be installed in the vicinity of the upper electrode 21. Further, the nozzle 33 may be configured to move (follow) with the movement of the plasma generation region S.

  Note that the processed processing gas supplied to the processing surface 101 by the processing gas supply unit 3 and subjected to the plasma processing in the plasma generation region S is preferably exhausted by an exhaust unit (not shown). ing. The exhaust means is not particularly limited, and examples thereof include a suction nozzle and a fan that exhausts the gas in the chamber when the upper electrode 21 and the lower electrode 22 are installed in the chamber.

  The energization means 4 includes a high-frequency power source 41 that applies a high-frequency voltage between the upper electrode 21 and the lower electrode 22, and a conductive wire 42 that conducts the upper electrode 21, the high-frequency power source 41, and the lower electrode 22. Further, the high frequency power supply 41 has a power adjusting unit (not shown) whose operation is controlled by the control means 7, so that the magnitude (power value) of the supplied power can be changed by the control of the control means 7. It has become. Although not shown, a matching circuit (impedance matching circuit) for the supplied power, a frequency adjusting means (circuit) for changing the frequency of the high frequency power supply 41, and a maximum value (amplitude) of the applied voltage of the high frequency power supply 41 are changed. Voltage adjustment means (circuit) and the like are installed as necessary. Thereby, the processing conditions of the plasma processing with respect to the workpiece | work 10 can be adjusted suitably.

When plasma processing is performed on the workpiece 10, the high frequency power supply 41 is activated and a high frequency voltage is applied between the upper electrode 21 and the lower electrode 22. As a result, an electric field is generated between the upper electrode 21 and the lower electrode 22, and when the processing gas is supplied to the processing surface 101 by the processing gas supply means 3, a discharge is generated and plasma is generated in the plasma generation region S. appear.
The frequency of the high frequency applied between the upper electrode 21 and the lower electrode 22 is not particularly limited, but is preferably 10 to 70 MHz. The high frequency RF power is not particularly limited, but is preferably 10 to 150 W.

The moving unit 5 includes a first moving unit 51 that relatively moves the upper electrode 21 and the lower electrode 22 (workpiece 10) two-dimensionally in the x-axis direction and the y-axis direction, and the upper electrode 21 and the lower electrode 22. (Work 10) and second moving means 52 that moves relatively in the z-axis direction.
As the first moving means 51, an NC (numerical control) stage moving device for moving the lower electrode 22 in the x-axis direction and the y-axis direction is used. The first moving means 51 moves the lower electrode 22 in the x-axis direction and the y-axis direction when the workpiece 10 is subjected to plasma processing, so that the processing target surface 101 of the workpiece 10 is two-dimensional with respect to the upper electrode 21. It is the moving means which moves automatically.
Such first moving means 51 is configured to be able to adjust the moving speed (that is, the relative moving speed between the upper electrode 21 and the workpiece 10), the stop time, and the like. The operation of the first moving means 51 is controlled by an NC (Numerical Control) control device 15.

On the other hand, as the second moving means 52, a moving device that moves the upper electrode 21 in the z-axis direction (does not move in the x-axis direction and the y-axis direction) is used. The second moving means 52 can adjust the gap distance between the upper electrode 21 and the surface to be processed 101 (in other words, the distance between the upper electrode 21 and the lower electrode 22). The operation of the second moving unit 52 is controlled by the control unit 7.
By the moving means 5 configured as described above, the upper electrode 21 is positioned at an arbitrary position (coordinates) in the three-dimensional space of xyz relative to the workpiece 10 in the space above the surface 101 to be processed. It becomes possible to move.

  The moving means 5 is not limited to that of the present embodiment, and any of the first moving means 51 and the second moving means 52 is responsible for movement in the x-axis direction, the y-axis direction, and the z-axis direction. Good. For example, the first moving means 51 may be responsible for the movement of the lower electrode 22 in the z-axis direction, and the second moving means 52 may be responsible for the movement of the upper electrode 21 in the x-axis direction and the y-axis direction. Further, the first moving means 51 may be responsible for moving the lower electrode 22 in all directions (x-axis direction, y-axis direction and z-axis direction). Conversely, the second moving means 52 has the same configuration. It may be.

Next, the circuit configuration of the plasma processing apparatus 1 will be described.
As shown in FIG. 1, the plasma processing apparatus 1 has an operation unit (input means) 11 that performs various operations such as input, a storage means 12, and a control that controls the overall operation (drive) of the plasma processing apparatus 1. Means 7, target shape data input unit 13, surface measuring instrument 14, NC control device 15 for controlling the operation of the first moving means 51 by NC control, and workpiece shape data input unit 16 for inputting the shape of the workpiece 10. And.

As the operation unit 11, for example, a touch panel including a keyboard, a liquid crystal display panel, an EL display panel, or the like can be used. In this case, the operation unit 11 displays (notifies) various kinds of information. It may also serve as a notification means).
The target shape data input unit 13 is a means for inputting target shape data indicating the target shape of the surface 101 of the workpiece 10. The target shape data is input from the target shape data input unit 13 to the control means 7.

  The surface measuring instrument 14 is a shape that indicates the shape of the processing target surface 101 of the workpiece 10 based on the shape of the processing target surface 101 of the workpiece 10, in particular, the detection unit that detects the presence / absence and level of unevenness and the detection result. And a data creation unit that creates data (concave and convex profile). The shape data of the surface to be processed 101 (data relating to the position (xyz coordinate) of each part of the surface to be processed 101) is input from the surface measuring instrument 14 to the control means 7.

  The workpiece shape data input unit 16 is a means for inputting the shape of the workpiece 10 before plasma processing (particularly the shape in plan view, and “shape” includes size). For example, the workpiece shape data input unit 16 may be configured to input the shape of the workpiece 10 every time a different workpiece 10 is subjected to plasma processing, or is frequently used in advance in the storage unit 12. A plurality of shapes of the workpiece 10 may be stored and selected from these. The latter is preferable from the viewpoint of simplification of work.

The storage means 12 has a recording medium, and on this recording medium, target shape data indicating the target shape of the processing target surface 101 input by the target shape data input unit 13, the target measured by the surface measuring instrument 14. The shape of the processing surface 101, the shapes of the plurality of workpieces 10, the shape of the workpiece 10 input or selected by the workpiece shape data input unit 16, and the like are stored.
Examples of the recording medium include RAM, ROM, flash memory, IC memory, HD (hard disk), and the like. Control such as writing (storage), rewriting, erasing, and reading in the storage unit 12 is performed by the control unit 7.

  The NC control device 15 is composed of, for example, a CPU or a computer such as a microcomputer or personal computer equipped with the CPU, and the NC control device 15 includes a plan program (movement pattern of the lower electrode 22) created by the control means 7. And data on the moving speed) and the like are input. The NC control device 15 controls the operation of the first moving unit 51 by NC control according to a preset program based on the corrected machining plan program or the like input from the control unit 7.

The control means 7 is composed of, for example, a CPU or a computer such as a microcomputer or personal computer equipped with the CPU. A signal from the operation unit 11, a target shape data input unit 13, data from the surface measuring instrument 14, data from the workpiece shape data input unit 16, and the like are input to the control unit 7.
The control means 7 creates a machining program for flattening the surface to be processed 101 based on the signal from the operation unit 11, data from the target shape data input unit 13 and the surface measuring instrument 14, and the like. Accordingly, the operation of each part of the plasma processing apparatus 1, for example, the operation of the processing gas supply means 3, the energizing means 4, the moving means 5, the positioning / separating means 6 and the like is controlled.

Next, the operation of the plasma processing apparatus 1 will be described.
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First, the operator uses the workpiece shape data input unit 16 to select the same shape data as the shape of the workpiece 10 to be plasma processed from the shape data of the plurality of workpieces 10 stored in the storage unit 12 in advance. When the same shape data is not stored in the storage unit 12, for example, the operator may directly input the shape, or the closest shape data may be selected from a plurality of stored shape data. The selected shape data may be corrected.

<2>
When the shape data of the workpiece 10 is input by the workpiece shape data input unit 16, the control unit 7 places the workpiece 10 so that the entire surface of the workpiece 10 (processing surface 101) is included in the placement surface 221. The situation of placing on the placement surface 221 is simulated, and among the plurality of pins 61, the pin 61 located on the outer side of the workpiece 10 and closest thereto is selected as a positioning pin.

At this time, preferably, in order to more reliably position the workpiece 10, the control means 7 and a pin 61 that abuts a predetermined side (one side surface) of the workpiece 10 and a side (side surface) adjacent to the one side. ) Are selected.
More preferably, the control means 7 selects a plurality of pins 61 that contact the predetermined one side, and also selects a plurality of pins 61 that contact a side (side surface) adjacent to the one side. Thereby, the workpiece 10 can be positioned more accurately.

  For example, FIG. 5A schematically shows a situation where the control means 7 simulates the situation where the work 10 is placed on the placement surface 221. In this case, the control means 7 61a and 61b are selected as the pins 61 that contact the side 103 of the workpiece 10, and 61c and 61d are selected as the pins 61 that contact the side 104 adjacent to the side 103.

<3>
Next, the control means 7 simulates a state in which the sides 103 and 104 of the workpiece 10 are brought into contact with the pins 61a to 61d selected as the positioning pins in the above <2>, and is included in the back surface 102 of the workpiece 10. A pin 61 that functions as a floating pin is selected from the plurality of pins 61.

  The pin 61 selected as the floating pin may be any pin included in the back surface 102 of the workpiece 10, but is preferably the pin 61 located at the edge of the workpiece 10 (for example, FIG. 5B). Inner pins 61e, 61f). Thereby, since the other site | part can be lifted from the mounting surface 221 with a part of outer periphery of the workpiece | work 10 contacting the mounting surface 221, the workpiece | work 10 is stabilized also in the floating state. Therefore, the workpiece 10 can be removed more easily.

  As described above, each pin 61 has the functions of both a positioning pin and a floating pin, and the control means 7 selects whether each pin 61 functions as a positioning pin or as a floating pin. . For this reason, it is possible to have more patterns of which pins 61 of the plurality of pins 61 function as positioning pins and which pins 61 function as floating pins, depending on the size, shape, and the like of the workpiece 10. The workpiece 10 can be positioned and removed easily and accurately.

<4>
Next, the control means 7 transmits a signal (command) for setting the pin 61 selected as the positioning pin to the protruding state and setting the other pins 61 to the accommodated state to the pin moving means control device 63 to control the pin moving means. The device 63 drives the corresponding solenoid (pin moving means 62) to execute the command. As a result, only the pin 61 selected as the positioning pin is in the protruding state.

After the pin 61 selected as the positioning pin is in the protruding state, the workpiece 10 is placed on the mounting surface 221 from a predetermined direction, and the side surface of the workpiece 61 is brought into contact with the side surface of each protruding pin 61. Perform positioning.
After the positioning of the workpiece 10 is completed, the control means 7 sends a signal (command) for setting the pin 61 selected as the positioning pin (that is, the protruding pin 61) to the accommodation state to the pin moving means control device 63. Then, the pin moving means control device 63 drives the corresponding solenoid (pin moving means 62) to execute the command.

<5>
Next, the control unit 7 controls the operation of the processing gas supply unit 3, the energization unit 4 and the moving unit 5 based on the created machining program, and performs plasma processing on the surface 101 to be processed of the workpiece 10.
Specifically, the control means 7 operates the high frequency power supply 41 at the frequency and size set in the machining program and opens the valve 35. Then, the mass flow controller 32 adjusts the gas flow rate to the amount set in the machining program, and the process gas is sent out from the gas cylinder 31. As a result, the processing gas flows through the processing gas supply channel 34 and is ejected from the nozzle 33. The ejected processing gas is supplied to the processing surface 101. On the other hand, by the operation of the high frequency power supply 41, a high frequency voltage is applied between the upper electrode 21 and the lower electrode 22, and an electric field is generated in the plasma generation region S.

The processing gas that has flowed into the plasma generation region S is activated by the discharge, and plasma is generated. Then, the generated plasma (activated gas) locally contacts the surface to be processed 101 of the workpiece 10, and plasma processing is performed on the contacted portion.
Next, the control means 7 moves the lower electrode 22 by the first moving means 51 (NC control device 15) based on the movement pattern and movement speed of the lower electrode 22 set in the machining program, and is set in the program. The upper electrode 21 is moved by the second moving means 52 based on the movement pattern of the lower electrode 22. As a result, the plasma generation region S and the workpiece 10 (surface to be processed 101) move relative to each other, and the distance between the upper electrode 21 and the lower electrode 22 changes based on the machining program. Plasma treatment is performed locally and continuously. As a result, the processing target surface 101 is flattened.

  Here, as described above, when the plasma processing is performed, all the pins 61 are in the accommodated state. That is, the front end surfaces 611 of all the pins 61 coincide with the placement surface 221 (become flush with each other). Therefore, assuming that the lower surface of the workpiece 10 is a flat surface, no gap is formed between the lower surface of the workpiece 10 and the mounting surface 221 when the workpiece 10 is mounted on the mounting surface 221. It will be. Thereby, since the whole area of the processing target surface 101 of the workpiece 10 can be processed with plasma in a desired state, a uniform and stable plasma processing can be performed on the entire processing target surface 101.

  For example, when the workpiece 10 is subjected to plasma processing, if one pin 61 included in the lower surface of the workpiece 10 is located further below the housed state, the tip surface 611 of the pin 61 and the workpiece An air gap is formed between the lower surface of 10. Then, due to the influence of the gap, the state of the plasma when the region corresponding to the gap on the surface 101 to be processed passes through the plasma generation region S changes from the desired state, and the portion is subjected to the plasma treatment. In some cases, the etching rate may decrease. Due to such a problem, a desired plasma process may not be performed on the entire surface 101 to be processed.

<6>
When the plasma processing on the workpiece 10 is completed, the control means 7 transmits a signal (command) for causing the pin 61 selected as the floating pin in <3> to be in the protruding state to the pin moving means control device 63 to move the pin. The means control device 63 drives the corresponding solenoid (pin moving means 62) so as to execute the command. As a result, the lower surface of the workpiece 10 is pressed by the pin 61 and is separated from the placement surface 221.

<7>
Finally, the workpiece 10 separated from the placement surface 221 is removed from the placement surface 221 by, for example, an operator or a robot arm. At this time, the workpiece 10 can be easily removed from the placement surface 221 by utilizing a gap formed between the workpiece 10 and the placement surface 221. As a result, damage (breakage) of the workpiece 10 when the workpiece 10 is removed from the placement surface 221 and damage (breakage) of the placement surface 221 due to sliding between the workpiece 10 and the placement surface 221 are prevented. .

The plasma processing apparatus of the present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these embodiments, and the configuration of each part is replaced with an arbitrary configuration having the same function. can do. Moreover, other arbitrary structures and processes may be added.
In the above-described embodiment, the form using the solenoid as the moving means for moving the pin between the protruding state and the moving state has been described. However, the moving means is not particularly limited as long as the pin can be moved to the above state. For example, it may be one using a motor, one using a hydraulic cylinder or a pneumatic cylinder, or the like.
Moreover, although embodiment mentioned above demonstrated the form in which the pin was inserted in the hole, it is not limited to this, For example, the form in which the pin is engaged in the hole may be sufficient. In this case, for example, by rotating the pin in the axial direction by a motor or the like, the pin can be moved between the protruding state and the accommodated state.

It is a figure (sectional view, side view, block diagram) showing a preferred embodiment of the plasma processing apparatus of the present invention. It is a perspective view of the lower electrode with which the plasma processing apparatus shown in FIG. 1 is provided. It is sectional drawing explaining the movement when the pin shown in FIG. 2 functions as a positioning pin. It is sectional drawing explaining the movement at the time of the pin shown in FIG. 2 functioning as a floating pin. It is the top view which simulated the situation where the workpiece | work 10 was mounted in the mounting surface.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Plasma processing apparatus 11 ... Operation part 12 ... Memory | storage means 13 ... Target shape data input part 14 ... Surface measuring device 15 ... NC controller 16 ... Work shape data input part 21 ... Upper electrode 22 ... Lower electrode 221 ... Upper surface (mounting surface) 222 ... Hole 24 ... Dielectric part 241 ... Recess 3 ... Process gas supply means 31 ... Gas cylinder (gas supply source) 32 ... Mass flow controller (flow rate) Adjustment means) 33 …… Nozzle 34 …… Processing gas supply flow path 35 …… Valve 4 …… Energization means 41 …… High frequency power supply 42 …… Conductor 5 …… Moving means 51 …… First moving means 52 …… Second Moving means 6 …… Positioning / separating means 61, 61a to 61f …… Pin 611 …… Tip surface 62 …… Pin moving means 63 …… Pin moving means controller 7 …… Control means 10 …… Workpiece 101 …… Processed surface 102 …… Back surface 103, 104 …… Side (side surface) S …… Plasma generation region

Claims (7)

An upper electrode and a lower electrode arranged opposite to each other;
A mounting portion including a mounting surface for mounting the workpiece so that a workpiece having a processing surface is positioned between the upper electrode and the lower electrode;
Protrusions provided on the mounting portion, and protruding and retracting from the mounting surface,
A processing gas supply means for supplying a processing gas to the surface to be processed;
Energization means for energizing between the upper electrode and the lower electrode,
The plasma processing apparatus, wherein the protrusion moves between a protruding state in which a front end surface thereof protrudes from the mounting surface and an accommodation state in which the protrusion matches the mounting surface.   The plasma processing apparatus according to claim 1, wherein the protrusion has a function as a positioning protrusion that positions the work by abutting the work against a side surface of the protrusion in the protruding state.   In the state where the workpiece is placed on the placement surface, the protrusion moves from the accommodated state to the protruding state, thereby pressing the lower surface of the workpiece at the tip thereof, The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus has a function as a separation protrusion that separates the pressed portion from the placement surface. A plurality of the protrusions are provided,
A plurality of the protrusions, in the protruding state, in a state where the workpiece is placed on the placement surface, and a positioning protrusion that positions the workpiece by contacting the workpiece to the side surface thereof, A separation protrusion for pressing the lower surface of the workpiece at the tip thereof and moving the pressed portion of the workpiece away from the placement surface by moving from the accommodated state to the protruding state; The plasma processing apparatus according to claim 1.   The plasma processing apparatus according to claim 4, wherein each of the protrusions functions as both a positioning protrusion and a separation protrusion.   The plasma processing apparatus according to claim 1, wherein the workpiece plasma processing is performed with the protrusions in the housed state.   The plasma processing apparatus according to claim 1, wherein the protrusion has the same dielectric constant as that of the mounting portion.

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