JP2008053367A - Plasma processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing apparatus capable of effectively and inexpensively performing plasma processing position selectively to a region of different shape on a processing surface of a work using one application electrode. <P>SOLUTION: The plasma processing apparatus 1 for applying plasma processing to a substrate (work) 10 comprises a ground electrode (first electrode) 2 for supporting a substrate 10, an application electrode (second electrode) 3, a power supply circuit 4, and a gas supply (gas supply means) 5. The gas supply 5 has 10 nozzles 510 to 519 for injecting predetermined gas to between the substrate 10 and the application electrode 3. The gas supply 5 is configured to supply plasma gas from a nozzle located at a position corresponding to the processing region among the nozzles 510 to 519, and to supply shield gas from a nozzle located at a position corresponding to a non-processing region side of a boundary part between the processing region and the non-processing region. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus.

2. Description of the Related Art Conventionally, apparatuses that perform plasma processing on the surface of a substrate (workpiece) are known.
Such a plasma processing apparatus performs plasma processing by introducing a plasma gas between electrodes to which a high-frequency voltage is applied to generate plasma and exposing the surface of the substrate to the plasma. The substrate in contact with the plasma reacts with the activated atoms (radicals) in the plasma and the substrate material, and this reactant is detached from the substrate, so that a plasma treatment such as etching that cuts the surface is performed. Is done.
At this time, the amount of processing changes according to the distance between the electrodes, that is, the electric field strength. By utilizing this, an electrode having a desired shape is prepared, and the substrate is processed into a shape reflecting the shape of the electrode by performing plasma treatment on the substrate using this electrode ( For example, see Patent Document 1).

FIG. 10 is a perspective view schematically showing a conventional plasma processing apparatus.
A plasma processing apparatus 100 shown in FIG. 10 is arranged to face a ground electrode 102 that supports a substrate (workpiece) 110 and the ground electrode 102 with the substrate 110 interposed therebetween so as to cover a part of the substrate 110. A power supply circuit 104 having a power supply for applying a high-frequency voltage between the application electrode 103, the ground electrode 102 and the application electrode 103, and a gas supply unit 105 for supplying a predetermined gas between the substrate 110 and the application electrode 103 And have.

In such a plasma processing apparatus 100, when a high-frequency voltage is applied between the ground electrode 102 and the application electrode 103 while supplying the plasma gas _GP for etching between the substrate 110 and the application electrode 103, the substrate 110. Plasma P is generated between the electrode 103 and the application electrode 103. The plasma P reacts with a part of the substrate 110 and forms an indentation 109 by etching.

In such an etching process, it is necessary to prepare the application electrode 103 whose surface facing the substrate 110 has the same shape as the opening of the recess 109. Specifically, when forming a recess having a width wider than the width W _{1 of the} recess 109, it is necessary to prepare an application electrode having a width wider than the width W ₂ of the application electrode 103. As described above, since it is necessary to prepare the dedicated application electrode 103 in accordance with the intended shape after processing, a large number of application electrodes 103 are required, the cost of the application electrode 103 increases, and the desired shape is obtained. It takes time to replace the application electrode 103 every time the change is made. In addition, even if the target shape after processing is the same, if the processing position on the substrate 110 is different, it is necessary to move the application electrode 103 relative to the substrate 110, which reduces the processing efficiency. Invited.

JP 9-31670 A

  An object of the present invention is to provide a plasma processing apparatus that can perform plasma processing that is position-selectively performed on regions of different shapes on a processing surface of a workpiece using one application electrode efficiently and at low cost. There is to do.

Such an object is achieved by the present invention described below.
The plasma processing apparatus of the present invention includes a first electrode that is electrically grounded,
A second electrode disposed opposite to the first electrode via a workpiece;
A power supply circuit comprising a power supply for applying a high-frequency voltage between the first electrode and the second electrode;
Gas supply means for supplying a plasma gas that is ionized by the action of the high-frequency voltage into plasma and a shield gas that is less easily ionized than the plasma gas, respectively, between the workpiece and the second electrode. And
A plasma processing apparatus for selectively performing plasma processing on a processing region of a part of the workpiece by a reaction between the plasma and the workpiece;
The gas supply unit selectively supplies the plasma gas toward the processing region, and supplies the shield gas toward the non-processing region side of the boundary between the processing region and the non-processing region. It is configured.
Thereby, the plasma processing apparatus which can perform the plasma processing which performs position-selectively with respect to the area | region of a different shape on the said process surface of the said workpiece | work using one said 2nd electrode efficiently and at low cost. Is obtained.

In the plasma processing apparatus of the present invention, the gas supply means includes a plurality of nozzles having openings that are opened between the workpiece and the second electrode;
A plasma gas supply source for supplying the plasma gas toward the nozzles;
A shield gas supply source for supplying the shield gas toward the nozzles;
The plasma gas is distributed to the nozzles that are connected to the supply sources and the plurality of nozzles, respectively, and are located at positions corresponding to the processing regions of the plurality of nozzles, and on the non-processing region side of the boundary portion It is preferable to have a gas switching means for distributing the shielding gas to the nozzles located at positions corresponding to.
Accordingly, the plasma gas can be selectively supplied toward the processing region, and the shield gas can be selectively supplied toward the non-processing region side of the boundary. it can.

In the plasma processing apparatus of the present invention, the gas switching means includes a plasma gas supply path for supplying the plasma gas to the nozzles, and
A first valve that is provided in the middle of each plasma gas supply path and opens and closes each plasma gas supply path;
A shield gas supply path for supplying the shield gas to the nozzles;
A second valve that is provided in the middle of each shield gas supply path and opens and closes each shield gas supply path;
The plasma gas is distributed from the plasma gas supply source to the nozzle through the plasma gas supply path in which the first valve is open, and the second gas is supplied from the shield gas supply source. It is preferable that the shield gas is distributed to the nozzles via the shield gas supply path in which the valve is open.
Thereby, since the opening / closing amount of the first valve and the opening / closing amount of the second valve can be controlled independently, the respective flow rates of the plasma gas and the shielding gas supplied from the nozzles are respectively determined. It can be controlled more precisely.

In the plasma processing apparatus of the present invention, the gas switching means temporarily stores the shield gas supplied from the shield gas supply source, and supplies the stored shield gas to each nozzle. Room,
A movable body capable of moving in the shielding gas storage chamber in the arrangement direction of the nozzles;
A plasma gas supply path that is provided in the moving body, communicates with the plasma gas supply source, and through which the plasma gas passes;
The plasma gas supply path is selectively connected to some of the plurality of nozzles by the movement of the moving body, and the plasma gas is distributed to the connected nozzles. Is preferred.
Thereby, the manufacturing cost of the plasma processing apparatus can be significantly reduced.

In the plasma processing apparatus of the present invention, it is preferable that the plurality of nozzles are arranged in parallel to the processing surface of the workpiece.
Accordingly, the selection of the nozzle to which the plasma gas is to be supplied and the selection of the nozzle to which the shield gas is to be supplied can be facilitated, and the plasma processing process can be simplified.

In the plasma processing apparatus of the present invention, it is preferable that each of the nozzles is provided so as to supply the plasma gas or the shield gas along a plane parallel to the processing surface of the workpiece.
As a result, the predetermined gases supplied from the nozzles are distributed at a uniform concentration on the processing surface. As a result, it is possible to perform the plasma processing on the processing region without unevenness and reliably prevent the plasma processing from being performed on the non-processing region.

In the plasma processing apparatus of the present invention, the processing region has a belt-like shape extending along the direction in which the plasma gas is ejected from the nozzle, and is continuous from one end to the other end of the workpiece. preferable.
Thereby, the plasma processing can be performed on the workpiece with a rectangular pattern having higher shape versatility.

In the plasma processing apparatus of the present invention, it is preferable that an inner diameter of each nozzle is 50 μm to 20 mm.
As a result, a sufficient position resolution in the processing region can be ensured, so that even when the area of the processing region is very small, the region can be subjected to plasma processing in a selective and reliable manner.

In the plasma processing apparatus of the present invention, it is preferable that each of the nozzles is made of a ceramic material.
Ceramic materials are extremely low in electrical conductivity, so they can prevent spark discharge reliably, and are excellent in heat resistance and weather resistance. Therefore, even if spark discharge occurs, the quality and deterioration of each nozzle can be prevented. Can do.

In the plasma processing apparatus of the present invention, it is preferable that a flow rate of the plasma gas or a flow rate of the shield gas per nozzle among the plurality of nozzles is 0.1 to 10 slm.
Accordingly, it is possible to reliably perform the plasma processing even on the workpiece having a large area while suppressing wasteful consumption of the plasma gas and the shield gas.

In the plasma processing apparatus of the present invention, it is preferable that a flow rate of the plasma gas per nozzle among the plurality of nozzles is equal to a flow rate of the shield gas per nozzle.
Thereby, for example, when performing the etching process on the processing region, the boundary between the processing region and the non-processing region becomes clear, and the processing accuracy can be increased.

In the plasma processing apparatus of the present invention, it is preferable that the flow rate of the plasma gas per nozzle among the plurality of nozzles is different from the flow rate of the shield gas per nozzle.
Accordingly, plasma processing is selectively performed on the processing area corresponding to the balance between the flow rate of the plasma gas and the flow rate of the shield gas in the processing surface. That is, the shape of the processing region can be adjusted by appropriately setting the difference between the flow rate of the plasma gas and the flow rate of the shield gas.

In the plasma processing apparatus of the present invention, it is preferable that the shield gas is mainly composed of air or nitrogen gas.
Since these gases are difficult to ionize and are very inexpensive, even if they are used in a large amount, it is difficult to cause an increase in plasma processing cost. Therefore, they are preferably used as the shielding gas.
In the plasma processing apparatus of the present invention, the output of the high-frequency voltage is preferably 10 W to 10 kW.
Thereby, plasma can be generated more stably.

In the plasma processing apparatus of the present invention, it is preferable that the first electrode and the second electrode are respectively provided so as to cover the entire workpiece.
Thereby, the plasma treatment can be performed uniformly over the entire workpiece. In addition, since it is not necessary to move the second electrode according to the position of the processing region, the time required for moving the second electrode can be omitted, and the processing time can be shortened.

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 schematically showing a first embodiment of the plasma processing apparatus of the present invention, FIG. 2 is a front view of the plasma processing apparatus shown in FIG. 1 viewed from the direction of arrow A, and FIG. FIG. 4 is a perspective view for explaining an example of a procedure for performing plasma processing using the plasma processing apparatus shown in FIG. 1. In the following description, the upper side in FIG. 2 is referred to as “upper” and the lower side is referred to as “lower”.

A plasma processing apparatus 1 shown in FIG. 1 is a so-called parallel plate type plasma processing apparatus, and performs various plasma processing such as etching processing, ashing processing, hydrophilic processing, and water repellent processing on a substrate (workpiece) 10. Is.
The plasma processing apparatus 1 includes a ground electrode (first electrode) 2 that supports a substrate (work) 10, an application electrode (second electrode) 3, a power supply circuit 4, and a gas supply unit (gas supply means). And 5. Hereinafter, each part will be described in detail. In the following description, a case where etching processing is performed as plasma processing will be described as an example.

The substrate 10 is subjected to plasma processing on the surface facing the application electrode 3 (hereinafter also referred to as “processing surface”) by the plasma processing apparatus 1.
Examples of the material constituting the substrate 10 include a material containing a component that reacts with activated atoms (radicals) contained in plasma, which will be described in detail later, to vaporize the reactant.
Specific examples of such components include Si (silicon), SiO ₂ , SiN, Si ₃ N ₄ silicon compounds, Al (aluminum), W (tungsten), Ti (titanium), Al—Si, and the like. And various organic materials such as polyolefin, polyimide, and the like.
In the case of ashing treatment, examples of the component include various resist materials.

The ground electrode 2 supports the entire lower surface of the substrate 10. Thereby, it can support so that the board | substrate 10 may not deform | transform unintentionally, and since the electric field strength of the whole board | substrate 10 can be made uniform, a plasma process can be performed uniformly throughout the board | substrate 10. FIG.
The ground electrode 2 is electrically grounded through a ground wire 21.
On the other hand, the application electrode 3 is disposed to face the ground electrode 2 with the substrate 10 interposed therebetween.
A high frequency voltage is applied between the ground electrode 2 and the application electrode 3 by a power supply circuit 4 described later. When a high-frequency voltage is applied between the electrodes, gas molecules existing between the substrate 10 and the applied electrode 3 are ionized to generate plasma.

The application electrode 3 is arranged so as to cover the entire substrate 10. Thereby, similarly to the ground electrode 2, the plasma treatment can be performed uniformly over the entire substrate 10. In addition, since it is not necessary to move the application electrode 3 in accordance with the position of the processing region, it is possible to reduce the processing time by omitting the time required to move the application electrode 3.
The ground electrode 2 and the application electrode 3 are made of a conductive material such as copper.
Further, the lower surface and the side surface of the application electrode 3 are each covered with a dielectric layer (not shown). Thereby, it is possible to prevent a spark discharge from occurring in the application electrode 3. As a result, it is possible to prevent a problem from occurring in the plasma processing apparatus 1 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.

The power supply circuit 4 applies a high frequency voltage between the ground electrode 2 and the application electrode 3. As a result, an electric field whose direction is reversed at a high frequency is induced in the gap between the ground electrode 2 and the application electrode 3.
Such a power supply circuit 4 includes a high-frequency power source 41, a wiring 42 that connects the high-frequency power source 41 and the ground electrode 2, a wiring 43 that connects the high-frequency power source 41 and the application electrode 3, and a matching box 44. And a switch 45 for opening and closing the power supply circuit 4.
The gas supply unit 5 supplies a predetermined gas between the substrate 10 and the application electrode 3.

  The gas supply unit 5 shown in FIG. 1 is opened between the substrate 10 and the application electrode 3, and includes ten nozzles 510 to 519 having supply ports (openings) 510a to 519a for ejecting a predetermined gas, A plasma gas supply source 53 that supplies a plasma gas toward each nozzle 510 to 519, a shield gas supply source 54 that supplies a shield gas toward each nozzle 510 to 519, each supply source 53 and 54, and each nozzle 510 To flow rate controllers (gas switching means) 52 for distributing plasma gas or shield gas supplied from the supply sources 53 and 54 to the nozzles 510 to 519, respectively.

In this embodiment, as an example, among the nozzles 510 to 519, the nozzle 514 supplies a plasma gas between the substrate 10 and the application electrode 3, and the remaining nozzles 510 to 513 and the nozzles 515 to 519 include: It is configured to supply shielding gas.
The plasma gas is a gas that generates plasma due to ionization of contained gas molecules by the action of a high-frequency voltage (the action of an electric field). Specific examples of the plasma gas include a mixed gas of a processing gas and a carrier gas such as He (helium) gas and Ar (argon) gas.
Among these, the component of the processing gas varies depending on the type of plasma processing.

For example, when the etching process is performed on the substrate 10, it differs depending on the constituent material of the substrate 10. When the constituent material of the substrate 10 is the above-described silicon-based compound, CF ₄ , CHF ₃ , C ₂ F ₆ , SF ₆ Such a fluorine-based gas, a chlorine-based gas such as CCl _{4, and} the like, and when the constituent material of the substrate 10 is the aforementioned metal material, a chlorine-based gas such as CCl ₄ , Cl ₂ , and BCl ₃ are listed. In the case where the constituent material of the substrate 10 is the organic material described above, an oxygen-based gas such as O ₂ can be used.
In addition, when subjected to a hydrophilic treatment for hydrophilizing the treated surface 11 of the substrate 10, as the process gas, it is possible to use O _{3, H} 2 _O or the like.
Moreover, when performing the water-repellent process which makes the process surface 11 of the board | substrate 10 water-repellent, the above-mentioned fluorine-type gas can be used as process gas.

The ratio (mixing ratio) occupied by the processing gas in the mixed gas is slightly different depending on the type of the processing gas and the carrier gas. For example, the ratio of the processing gas in the mixed gas is set to about 0.1 to 10%. Is preferable, and it is more preferable to set to about 0.5 to 5%.
In the case where plasma gas is supplied from a plurality of nozzles, different types of plasma gas may be supplied from each nozzle.

  On the other hand, the shielding gas is a gas in which contained gas molecules are less likely to be ionized than the plasma gas. A specific shielding gas is preferably a gas mainly composed of air or nitrogen gas. Since these gases are less likely to be ionized than the plasma gas as described above and are very inexpensive, they are preferably used as a shielding gas because they are unlikely to cause an increase in plasma processing cost even when used in large amounts.

As shown in FIG. 2, the nozzle 514 supplies plasma gas by changing the gas components supplied from the nozzles 510 to 519 as described above, whereby a space 61 in which the plasma gas exists at a high concentration is formed. It is formed.
In addition, the nozzles 510 to 513 supply the shielding gas, thereby the space 62 in which the shielding gas exists at a high concentration, and the nozzles 515 to 519 supply the shielding gas, thereby the space 63 in which the shielding gas exists at a high concentration. And are formed.
2 and 4 are virtual lines that schematically show the outlines of the spaces 61, 62, and 63, respectively.

  When a high frequency voltage is applied to the application electrode 3 with an output that does not ionize the plasma gas and does not ionize the shield gas in a state where the gas having different components is selectively filled in this way, Due to the above action, molecules in the plasma gas are ionized to generate plasma P in the space 61. As a result, the region covered with the space 61 of the processing surface 11 of the substrate 10 is processed with activated atoms (radicals) in the plasma P.

On the other hand, since the space 62 and the space 63 are filled with the shielding gas, the generation of plasma is prevented. Thereby, the area | region covered with the space 62 and the space 63 of the process surface 11 of the board | substrate 10 is not processed by a plasma, and can maintain an initial state.
That is, according to the plasma processing apparatus of the present invention, plasma processing can be performed on regions having different shapes with one application electrode 3 by controlling the spaces for supplying the plasma gas and the shield gas, respectively. . Further, plasma processing can be performed on regions at different positions without changing the position of the application electrode 3 with respect to the substrate 10.
The plasma treatment will be described later in detail.

As a material constituting each nozzle 510 to 519, a material having low electrical conductivity is preferable. Thereby, it is possible to prevent a spark discharge from occurring in each of the nozzles 510 to 519. As a result, it is possible to prevent a problem from occurring in the plasma processing apparatus 1.
Specific examples of materials having low electrical conductivity include various ceramic materials such as alumina, zirconia, silicon nitride, and silicon carbide, various resin materials such as polyolefin and polyimide, and plasma treatment includes hydrophilic treatment or water repellency. In the case of performing the treatment, silicon or the like is further included.

Among these, it is preferable that the material which comprises each nozzle 510-519 is a ceramic material. The ceramic material has extremely low electrical conductivity, so it can prevent spark discharge reliably, and it has excellent heat resistance and weather resistance. Therefore, even if spark discharge occurs, the nozzles 510-519 are surely prevented from being altered or deteriorated. can do.
The inner diameters of the nozzles 510 to 519 are each preferably about 50 μm to 20 mm, and more preferably about 300 μm to 3 mm. As a result, a sufficient position resolution in the processing region can be ensured, so that even when the area of the processing region is very small, the region can be subjected to plasma processing in a selective and reliable manner.

  Further, the nozzles 510 to 519 are arranged in parallel to the processing surface 11 of the substrate 10 as shown in FIGS. 1 and 2. As a result, the boundary surfaces of the spaces 61, 62, 63 are perpendicular to the processing surface 11 of the substrate 10. For this reason, each space 61, 62, 63 reliably covers a part of the processing surface 11, and it becomes easy to correspond each space 61, 62, 63 to the processing area of the processing surface 11. As a result, it is possible to easily select the nozzle to which the plasma gas is to be supplied and the nozzle to be supplied with the shield gas, thereby simplifying the plasma processing process.

Further, among the supply ports 510a to 519a, the supply port 514a is provided so as to supply the plasma gas along a plane parallel to the processing surface 11 of the substrate 10, as shown in FIG. Further, the supply ports 510a to 513a and the supply ports 515a to 519a are also provided so as to supply shield gas along a plane parallel to the processing surface 11 of the substrate 10, as shown in FIG. As a result, the predetermined gas supplied from the supply ports 510a to 519a is distributed in the spaces 61, 62, and 63 at a uniform concentration. As a result, the region covered with the space 61 of the processing surface 11 of the substrate 10 can be subjected to the plasma processing without unevenness, and the plasma processing can be reliably prevented from being performed on the region covered with the space 62 and the space 63. .
Therefore, for example, when etching is performed on the substrate 10, variations in the processing amount can be suppressed in the region covered with the space 61.

The flow rate controller 52 is connected to the plasma gas supply source 53 via a pipe 561 and is connected to the shield gas supply source 54 via a pipe 562.
The flow rate controller 52 and the nozzles 510 to 519 are connected to each other via a pipe 55.
As shown in FIG. 3, two systems of pipes 571 and 572 are disposed inside the flow rate controller 52.
Among these, one end of the pipe 571 is connected to the end of the pipe 561 opposite to the plasma gas supply source 53, and the other end of the pipe 571 is branched into two at ten locations inside the flow rate controller 52. The other ends of the branched pipes 571 are connected to the ends of the ten pipes 55 opposite to the nozzles 510 to 519, respectively.

On the other hand, one end of the pipe 572 is connected to the end of the pipe 562 opposite to the gas storage portion 54, and the other end of the pipe 572 branches at ten locations inside the flow rate controller 52, and the branched pipe Each other end of 572 is connected to the other end of each of the nozzles 510 to 519 of the ten pipes 55 together with the other ends of the aforementioned branched pipes 571.
Accordingly, the plasma gas supply path for supplying the plasma gas supplied from the plasma gas supply source 53 to the nozzles 510 to 519 is constituted by the pipe 561, the pipe 571, and the pipe 55.

Further, the pipe 562, the pipe 572, and the pipe 55 constitute a shield gas supply path that supplies the shield gas supplied from the shield gas supply source 54 to the nozzles 510 to 519.
Further, a valve (first valve) 581 is provided in the middle of the pipe 571 branched into ten, and similarly, a valve (second valve) is provided in the middle of the pipe 572 branched into ten. Valve) 582 is provided.

Further, the flow rate controller 52 shown in FIG. 3 includes a control unit 59 that controls the opening / closing amounts of the valves 581 and 582. The ten valves 581 and the ten valves 582 described above are connected to the control unit 59 via wiring 591. As a result, the control unit 59 can independently control the open / close amounts of the valves 581 and 582, so that the flow rates of the plasma gas and the shield gas supplied from the nozzles 510 to 519 are more precisely controlled. can do.
In such a flow rate controller 52, the plasma gas is distributed from the plasma gas supply source 53 to the nozzles 510 to 519 through the plasma gas supply path in which the valve 581 is open. .

  Further, the shield gas is distributed from the shield gas supply source 54 to the nozzles 510 to 519 through the shield gas supply path in which the valve 582 is open. By using the flow rate controller 52 and setting the type and flow rate of the gas distributed to each of the nozzles 510 to 519, the plasma gas and the shield gas can be selectively supplied toward a predetermined region. It becomes easy.

Next, a series of operations of the plasma processing apparatus 1 when the plasma processing apparatus 1 performs plasma processing on the substrate 10 will be described in order.
First, the substrate 10 is placed on the ground electrode 2.
Here, a case will be described as an example in which plasma processing is performed on a region (hereinafter referred to as a “processing region”) 11a to be subjected to plasma processing in the processing surface 11 of the substrate 10 illustrated in FIG.

Next, in the processing surface 11 of the substrate 10, the plasma gas _GP is supplied to the space 61 covering the processing region 11 a and the space covering the region other than the processing region 11 a (hereinafter referred to as “non-processing region”). supplying a shield gas _{G S} 62 and space 63.
Specifically, to operate the gas supply unit 5, between the substrate 10 and the applied electrode 3, a plasma gas _{G P} from the nozzle 514, the shielding gas _{G S} from the nozzles 515 to 519 Metropolitan and the nozzles 510 to 513 Are supplied respectively. Thus, present in the plasma gas G _P is a high concentration in the space 61 shown in FIG. 4, the space 62 and space 63 to cover the non-processing region so that the shield gas G _S is present in high concentrations.

In this case, the flow rate of the plasma gas _{G P} in the nozzle 514, and the flow rate of the shield gas _{G S} in each nozzle 510～513,515～519 each is preferably about 0.1～10Slm, 0.5 to More preferably, it is about 5 slm. Thus, while suppressing wasteful consumption of the plasma gas G _P and shield gas G _S, it can be reliably performed even plasma treatment on a large substrate 10 area.

The flow rate of the plasma gas _{G P} in the nozzle 514 is preferably set to be equal to the flow rate of the shield gas _{G S} in each nozzle 510～513,515～519. Thereby, the gas supplied from each nozzle 510-519 occupies equal volume, respectively. Thus, for example, plasma gas G _P supplied from the nozzle 514, in the vicinity of the plane including the boundary between the nozzle 514 and the nozzle 513 is more reliably prevented its spread by the shield gas G _S supplied from the nozzle 513 The Rukoto.

The plasma gas G _P is in the vicinity of the plane including the boundary between the nozzle 514 and the nozzle 515, and thus be more reliably prevented its spread by the shield gas G _S supplied from the nozzle 515. As a result, the plasma gas G _P, while present in high concentration, especially in the space 61, with most no longer exist in the space 62 and space 63, the shielding gas G _S is present in particularly high concentration in the space 62 and space 63 On the other hand, the space 61 hardly exists.
Therefore, for example, when the etching process is performed on the processing region 11a, the boundary between the processing region 11a and the adjacent non-processing region becomes clear, and the processing accuracy can be increased.

Further, the boundary surface between the space 61 and the space 62 and the boundary surface between the space 61 and the space 63 are parallel to each other as shown in FIG. Thereby, when a high frequency voltage is applied between the ground electrode 2 and the application electrode 3, plasma P is generated in the space 61, and the processing surface 11 is along the direction in which the plasma gas _GP is ejected from the nozzle 514. Thus, the plasma treatment can be performed on the extending belt-like region. This band-like region is continuous from one end of the processing surface 11 to the other end. Thus, since the area | region which performs plasma processing has comprised strip | belt shape, plasma processing can be performed with respect to the board | substrate 10 by the rectangular pattern with the high versatility in a shape.

Next, the power supply circuit 4 is operated, and a high frequency voltage is applied between the ground electrode 2 and the application electrode 3. Thereby, an electric field whose direction is reversed at a high frequency is induced between the ground electrode 2 and the application electrode 3. The molecules in the plasma gas _GP existing in the space 61 are ionized by the energy of the electric field, and the plasma P is generated in the space 61 as shown in FIG.
On the other hand, the shielding gas G _S present in the space 62 and space 63, also by applying a high frequency voltage between the electrodes hardly varies.

As a result, as shown in FIG. 4, the plasma processing is selectively performed with respect to the region covered with the space 61 in the processing surface 11 of the substrate 10, that is, the processing region 11 a.
For example, when etching is performed, activated atoms (radicals) contained in the plasma P react with the processing region 11 a of the substrate 10. Then, when the reaction product is vaporized, the processing region 11a of the substrate 10 is etched, and a recess 9 as shown in FIG. 4 is formed.
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, the plasma P can be generated stably.

The output of the high frequency voltage, the output more ionized plasma gas G _P, and is applied in less than the output of ionized shielding gas G _S. Specifically, the type of (composition) or a plasma gas _{G P} and the shield gas _{G S,} varies depending on the area and the like of the ground electrode 2 and the applied electrode 3 is preferably about 10W~10kW, 100W~1kW More preferred is the degree. Thereby, the plasma P can be generated more stably.

The flow rate of the plasma gas _{G P} in the nozzle 514 may be set to differ from the flow rate of the shield gas _{G S} in each nozzle 510～513,515～519. With such a setting, the plasma gas _{G P} supplied from the nozzle 514, the shield gas _{G S} supplied from each nozzle 510～513,515～519 occupy different volumes respectively. Therefore, among the treated surface 11 of the substrate 10, so that the regioselectively plasma treatment on regions in accordance with the balance between the flow rate of the plasma gas G _P flow rate and the shielding gas G _S is made. That is, the difference between the flow rates of the shield gas G _S of the plasma gas G _P by appropriately setting, it is possible to adjust the shape of the processing region.

  5 to 8 are perspective views for explaining another example of a procedure for performing plasma processing using the plasma processing apparatus shown in FIG. In FIGS. 5 to 8, the application electrode 3 and the power supply circuit 4 are omitted in order to avoid complication of the drawings. 5 to 8 are virtual lines schematically showing the outlines of the spaces 61, 62, and 63, respectively.

For example, when the flow rate of the plasma gas G _P is greater than the flow rate of the shield gas G _S, since the plasma gas G _P occupies a larger volume than the shield gas G _S, as shown in FIG. 5, diverging farther from the supply port 514a Show a tendency to When a high frequency voltage is applied between the electrodes in this state, plasma P is generated in a space 61 as shown in FIG.
As a result, as shown in FIG. 5, the plasma processing is selectively performed with respect to a region having a substantially fan shape in plan view. For example, when an etching process is performed as a plasma treatment, a recess 9 as shown in FIG. 5 can be formed.

On the other hand, for example, when the flow rate of the plasma gas G _P is smaller than the flow rate of the shield gas G _S, since the plasma gas G _P occupies a smaller volume than the shield gas G _S, as shown in FIG. 6, away from the supply port 514a It shows a tendency to converge. When a high frequency voltage is applied between the electrodes in this state, plasma P is generated in a space 61 as shown in FIG.
As a result, as shown in FIG. 6, the plasma processing is performed in a position-selective manner on a region that has a substantially fan shape in plan view. For example, when etching is performed as a plasma treatment, a recess 9 as shown in FIG. 6 can be formed.
Note that, as described above, if the flow rate of the plasma gas G _P is different from the flow rate of the shield gas G _S, the difference in these flow rates, but preferably not more than 5 slm, and more preferably not more than 3 slm. Thereby, it is possible to perform the plasma treatment in a position-selective manner while clearly maintaining the boundary between the region where the plasma treatment is performed and the region where the plasma treatment is not performed.

In the plasma processing apparatus 1 shown in FIG. 4, the plasma gas _GP is supplied from one nozzle 514 among the nozzles 510 to 519, but the plasma gas _GP is supplied from two or more nozzles. It may be.
The plasma processing apparatus 1 shown in Figure 7 consists of three nozzles 513 to 515 so as to supply the plasma gas _{G P,} set from the nozzles 510～512,516～519 to supply shield gas _{G S} Has been. Thereby, it is possible to perform plasma processing in a position-selective manner on a region having a width about three times that of the processing region 11a shown in FIG. For example, when the etching process is performed as the plasma processing, as shown in FIG. 7, the concave portion 9 wider than the concave portion 9 shown in FIG. 3 can be formed.

Note that the plasma processing apparatus of the present invention may supply the plasma gas toward the processing region and supply the shielding gas toward at least the non-processing region side of the boundary between the processing region and the non-processing region.
Specifically, the plasma processing apparatus 1 shown in FIG. 8 supplies the plasma gas _GP from the nozzle 514 located at a position corresponding to the processing region 11b toward the space 61, and the processing region 11b and the non-processing region. from the nozzle 513 and the nozzle 515 Metropolitan in corresponding positions in the non-processing region side of the boundary portion of, and is configured to supply shielding gas G _S towards the space 62 and space 63 respectively. Further, the nozzles 510 to 512 and the nozzles 516 to 519 are set so as not to supply any gas. Also in such a plasma processing apparatus 1, the same operation and effect as the plasma processing apparatus 1 shown in FIG. 3 can be obtained, and the concave portion 9 equivalent to the concave portion 9 shown in FIG. 3 can be formed. Further, there is an advantage that the amount of shield gas G _S can be significantly reduced.

Here, when the substrate 10 is etched by the plasma processing apparatus 1, the plasma processing apparatus 1 obtains data (information) about the height of the processing surface 11 of the substrate 10 (not shown). It is preferable to have.
The height measuring means compares the difference between the shape of the substrate 10 and the target shape based on the data acquired by measurement, and derives a region (processing region) to be etched. And based on the data regarding this area | region, operation | movement of the flow controller 52 is controlled by the control part which is not shown in figure, and the shape of the board | substrate 10 is etched into the target shape.
Specifically, toward the processing region supplying a plasma gas G _P, so as to supply the shield gas G _S toward the untreated region adjacent to this region, the plasma gas G _P and shielding gas flowing through each nozzle the flow rate of G _S may be adjusted by flow controller 52.

<Second Embodiment>
Next, a second embodiment of the plasma processing apparatus of the present invention will be described.
FIG. 9 is a view for explaining the configuration of the gas supply means provided in the second embodiment of the plasma processing apparatus of the present invention.
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 the present embodiment is the same as that of the first embodiment except that the configuration of the flow rate controller is different.
A flow rate controller (gas switching means) 52 shown in FIG. 9 includes a chamber 520 provided therein with a shield gas storage chamber for temporarily storing the shield gas supplied from the shield gas supply source 54, and a shield gas storage chamber. The movable body 60 is movable along the arrangement direction of the nozzles 510 to 519, and a pipe 571 is provided on the movable body 60.

The chamber 520 is a container that can maintain airtightness inside. An opening on the opposite side of each nozzle 510 to 519 of the pipe 55 is opened in the shield gas storage chamber configured by the internal space of the chamber 520.
Further, an opening on the opposite side of the pipe 562 from the shield gas supply source 54 is also opened in the shield gas storage chamber, and a valve 582 is provided in the middle of the pipe 562.

The moving body 60 moves along the arrangement direction of the nozzles 510 to 519 by the moving mechanism 601. The moving mechanism 601 shown in FIG. 9 can move the moving body 60 along the track 603 by pulling the moving body 60 with the wire 602.
This moving body 60 is provided with a part of the pipe 571. One end of the pipe 571 is connected to the end of the pipe 561 opposite to the plasma gas supply source 53, and the other end is branched into three in the moving body 60. The other ends of the branched pipes 572 are connected via pipes 55 connected to three adjacent nozzles (in the present embodiment, the nozzles 513 to 515) of the nozzles 510 to 519, respectively. ing. The connecting portion between the pipe 572 and the pipe 55 is in sliding contact, for example. When the axis of the pipe 572 and the axis of the pipe 55 coincide, the plasma gas flows from the pipe 572 toward the pipe 55. It is sure to flow. Further, when the moving body 60 moves from this state, the pipe 572 and the pipe 55 are reliably separated.
In such a plasma processing apparatus 1, the plasma gas supply path for supplying the plasma gas supplied from the plasma gas supply source 53 to the nozzles 513 to 515 is constituted by the pipe 561, the pipe 571, and the pipe 55.

Further, valves 581, 581, and 581 are respectively provided in the middle of the pipe 571 branched into three.
Furthermore, each valve 581, 581, 581 and valve 582 and the control unit 59 are connected via a wiring 591, and the open / close amount of each valve 581, 581, 581 and valve 582 can be controlled independently. Can do.

In such a plasma processing apparatus 1, the plasma gas supply path is selectively transferred to some of the nozzles 510 to 519 (in the present embodiment, the nozzles 513 to 515) by the movement of the moving body 60. The plasma gas is distributed to the connected nozzles 513 to 515.
The flow controller 52 as described above is effective when the plasma processing apparatus 1 is operated as shown in FIG. 8, for example.
Moreover, since the flow controller 52 has a very simple structure, the manufacturing cost of the plasma processing apparatus 1 can be greatly reduced.

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.
The plasma gas may be supplied from any one of the nozzles 510 to 519, or may be supplied from the nozzle 510 or the nozzle 519. For example, when plasma gas is supplied from the nozzle 510 and shield gas is supplied from the nozzles 511 to 519, such a plasma processing apparatus 1 is used when plasma processing is performed on the edge of the substrate 10. Preferably used. In the case of the plasma processing apparatus 1 shown in FIG. 2, the plasma gas diffuses to the right side of the nozzle 510, but when the right edge of the substrate 10 is processed, the diffused plasma gas is not at all with respect to the substrate 10. This is because there is no adverse effect.
In the above embodiment, the number of nozzles is 10. However, the number of nozzles is not particularly limited, and may be set as appropriate according to the inner diameter of the nozzle and the size of the substrate 10. In addition, since the position resolution of the area | region which supplies gas becomes high, so that there are many nozzles, a process precision can be improved.

1 is a perspective view schematically showing a first embodiment of a plasma processing apparatus of the present invention. It is the front view which looked at the plasma processing apparatus shown in FIG. 1 from the direction of arrow A. It is a figure for demonstrating in detail the structure of the gas supply means shown in FIG. It is a perspective view for demonstrating an example of the procedure which performs a plasma process using the plasma processing apparatus shown in FIG. It is a perspective view for demonstrating the other example of the procedure which performs a plasma process using the plasma processing apparatus shown in FIG. It is a perspective view for demonstrating the other example of the procedure which performs a plasma process using the plasma processing apparatus shown in FIG. It is a perspective view for demonstrating the other example of the procedure which performs a plasma process using the plasma processing apparatus shown in FIG. It is a perspective view for demonstrating the other example of the procedure which performs a plasma process using the plasma processing apparatus shown in FIG. It is a figure for demonstrating the structure of the gas supply means with which 2nd Embodiment of the plasma processing apparatus of this invention is provided. It is a perspective view which shows the conventional plasma processing apparatus typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plasma processing apparatus 2 ... Ground electrode 21 ... Ground wire 3 ... Applied electrode 4 ... Power supply circuit 41 ... High frequency power supply 42, 43 ... Wiring 44 ... Matching device 45 ... Switch 5 ... Gas Supply part 510-519 …… Nozzle 510a-519a …… Supply port 52 …… Flow rate controller 520 …… Chamber 53 …… Plasma gas supply source 54 …… Shield gas supply source 55, 561, 562, 571, 572 …… Piping 581, 582 ... Valve 59 ... Control unit 591 ... Wiring 60 ... Moving body 601 ... Moving mechanism 602 ... Wire 603 ... Track 9 ... Recess 10 ... Substrate (workpiece) 11 ... Processing surface 11a, 11b... Processing regions 61, 62, 63 .. space 100... Plasma processing apparatus 102 .. ground electrode 103... Application electrode 104. Gas supply unit 109 ...... recess 110 ...... substrate (workpiece) P ...... plasma G _P ...... plasma gas G _S ...... shielding gas W _{1, W 2} ...... width

Claims (15)

An electrically grounded first electrode;
A second electrode disposed opposite to the first electrode via a workpiece;
A power supply circuit comprising a power supply for applying a high-frequency voltage between the first electrode and the second electrode;
Gas supply means for supplying a plasma gas that is ionized by the action of the high-frequency voltage into plasma and a shield gas that is less easily ionized than the plasma gas, respectively, between the workpiece and the second electrode. And
A plasma processing apparatus for selectively performing plasma processing on a processing region of a part of the workpiece by a reaction between the plasma and the workpiece;
The gas supply unit selectively supplies the plasma gas toward the processing region, and supplies the shield gas toward the non-processing region side of the boundary between the processing region and the non-processing region. A plasma processing apparatus characterized by being configured. The gas supply means includes a plurality of nozzles having openings that open between the workpiece and the second electrode;
A plasma gas supply source for supplying the plasma gas toward the nozzles;
A shield gas supply source for supplying the shield gas toward the nozzles;
The plasma gas is distributed to the nozzles that are connected to the supply sources and the plurality of nozzles, respectively, and are located at positions corresponding to the processing regions of the plurality of nozzles, and on the non-processing region side of the boundary portion The plasma processing apparatus according to claim 1, further comprising: a gas switching unit that distributes the shielding gas to nozzles located at positions corresponding to. The gas switching means includes a plasma gas supply path for supplying the plasma gas to the nozzles, and
A first valve that is provided in the middle of each plasma gas supply path and opens and closes each plasma gas supply path;
A shield gas supply path for supplying the shield gas to the nozzles;
A second valve that is provided in the middle of each shield gas supply path and opens and closes each shield gas supply path;
The plasma gas is distributed from the plasma gas supply source to the nozzle through the plasma gas supply path in which the first valve is open, and the second gas is supplied from the shield gas supply source. The plasma processing apparatus according to claim 2, wherein the shield gas is distributed to the nozzles through the shield gas supply path in which the valve is open. The gas switching unit temporarily stores the shield gas supplied from the shield gas supply source, and supplies the stored shield gas to the nozzles, respectively.
A movable body movable in the shielding gas storage chamber in the arrangement direction of the nozzles;
A plasma gas supply path that is provided in the moving body, communicates with the plasma gas supply source, and through which the plasma gas passes;
The plasma gas supply path is selectively connected to some of the plurality of nozzles by the movement of the moving body, and the plasma gas is distributed to the connected nozzles. Item 3. The plasma processing apparatus according to Item 2.   The plasma processing apparatus according to claim 2, wherein the plurality of nozzles are arranged in parallel to a processing surface of the workpiece.   6. The plasma processing apparatus according to claim 2, wherein each of the nozzles is provided so as to supply the plasma gas or the shield gas along a plane parallel to a processing surface of the workpiece.   The plasma processing apparatus according to claim 6, wherein the processing region has a strip shape extending along a direction in which the plasma gas is ejected from the nozzle, and is continuous from one end to the other end of the workpiece.   The plasma processing apparatus according to claim 2, wherein each nozzle has an inner diameter of 50 μm to 20 mm.   The plasma processing apparatus according to claim 2, wherein each nozzle is made of a ceramic material.   The plasma processing apparatus according to claim 2, wherein a flow rate of the plasma gas or a flow rate of the shield gas per nozzle among the plurality of nozzles is 0.1 to 10 slm.   The plasma processing apparatus according to claim 2, wherein a flow rate of the plasma gas per nozzle among the plurality of nozzles is equal to a flow rate of the shield gas per nozzle.   The plasma processing apparatus according to claim 2, wherein a flow rate of the plasma gas per nozzle among the plurality of nozzles is different from a flow rate of the shield gas per nozzle.   The plasma processing apparatus according to claim 1, wherein the shield gas is mainly composed of air or nitrogen gas.   The plasma processing apparatus according to claim 1, wherein the output of the high-frequency voltage is 10 W to 10 kW. The plasma processing apparatus according to claim 1, wherein each of the first electrode and the second electrode is provided so as to cover the entire workpiece.

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