Plasma treatment device and plasma treatment method

Abstract

A plasma treatment device for subjecting the surface of a workpiece that is a tool to a plasma treatment using plasma, said plasma treatment device comprising: a vacuum container that forms a vacuum chamber; a stage that is installed in the vacuum chamber; an insulating container that is disposed on the stage and forms a treatment chamber in which the workpiece is accommodated; and an antenna that is disposed on the periphery of the insulating container in the vacuum chamber and generates plasma in the treatment chamber.

Description

Plasma processing apparatus and plasma processing method

[0001] The present invention relates to a plasma processing apparatus and a plasma processing method for processing the surface of a tool using plasma.

[0002] Conventionally, there have been so-called coated tools, in which a coating treatment (coating treatment) is applied to the surface of a substrate made of tool steel or cemented carbide to impart additional properties such as wear resistance and heat resistance to the substrate in addition to its inherent properties. With use, such tools reach the end of their service life as the coating formed on the surface wears and peels off. While such used tools have traditionally been discarded without being reused, in recent years, they have been recycled by thoroughly removing (de-coating) the coating from the surface of used tools and then coating them again.

[0003] A known example of an apparatus for removing coatings from tool surfaces using plasma is the plasma processing apparatus disclosed in Patent Document 1. As shown in Figures 7 and 8, this plasma processing apparatus is configured to place a number of drills, which are the workpieces, on a disk-shaped stage installed in a vacuum chamber, introduce argon gas into the vacuum chamber, generate inductively coupled plasma within the vacuum chamber using an antenna installed outside the vacuum chamber, and apply a bias voltage to the stage, causing positive ions in the plasma to be incident on the coatings on the drill surfaces, thereby removing the coatings. In this plasma processing apparatus, the stage rotates around its own axis, and multiple small stages arranged circumferentially within the stage also rotate around their own axes, so that the coatings on the multiple drills placed on the stage can be removed uniformly.

[0004] Japanese Patent Application Publication No. 2023-004296

[0005] However, when using the plasma processing apparatus described in the aforementioned Patent Document 1 to simultaneously plasma-treat a large number of heavy tools, such as hobs, the stage structure must be made stronger and more complex than when plasma-treating lightweight drills, which increases the cost of the apparatus and the likelihood of malfunctions. Furthermore, since the volume of the workpiece is larger than that of a drill, it is difficult to cool the tools that have accumulated heat during plasma processing. In the above-mentioned apparatus, it is difficult to employ a cooling structure, such as water cooling, for the stage with a complex rotation mechanism, and cooling by heat dissipation or the like cannot be expected. These issues apply not only to apparatuses that remove coatings from tools using plasma, but also to apparatuses that deposit coatings on tools using similar mechanisms.

[0006] The present invention has been made to solve such problems, and its main objective is to provide a plasma processing apparatus that uses plasma to process the surface of a tool, and that can efficiently suppress the temperature rise of the tool during plasma processing, even for heavy tools such as hobs, with an inexpensive configuration, and that can perform film removal processing and film formation processing uniformly.

[0007] That is, the plasma processing apparatus of the present invention uses plasma to perform plasma processing on the surface of a workpiece, which is a tool, and is characterized by comprising a vacuum container forming a vacuum chamber, a stage installed within the vacuum chamber, an insulating container placed on the stage and forming a processing chamber for accommodating the workpiece, and an antenna placed around the insulating container within the vacuum chamber and for generating plasma within the processing chamber.

[0008] In this way, a small processing chamber isolated by an insulating container is formed above the stage in the vacuum chamber, and tools are housed in the processing chamber while plasma is generated and plasma processing is performed. This allows a larger ratio of the number of antennas generating plasma to the number of tools to be processed, thereby enabling uniform plasma processing of the objects to be processed without rotating the stage. In addition, since there is no need to provide a rotation mechanism on the stage, the structure can be simplified, and a cooling structure such as water cooling can be formed within the stage, for example, making it possible to efficiently suppress the temperature rise of the tools during plasma processing.

[0009] Furthermore, the plasma processing apparatus is for plasma processing the surfaces of a plurality of workpieces at once, and preferably includes a plurality of insulating containers and a plurality of antennas disposed around each of the insulating containers. In this way, the ratio of the number of antennas to the number of insulating containers and tools can be increased, and the workpieces can be subjected to more uniform plasma processing.

[0010] In addition, it is preferable that the plurality of insulating containers are individually provided for each of the plurality of workpieces in the plasma processing apparatus, which further increases the ratio of the number of antennas to the number of tools, thereby enabling more uniform plasma processing of the workpieces.

[0011] Furthermore, the plasma processing apparatus preferably includes a gas supply mechanism for supplying a plasma generating gas into the insulating container, the gas supply mechanism preferably including a gas source and a gas pipe having an upstream end connected to the gas source through which the plasma generating gas flows and a downstream end opening into the insulating container. In this manner, plasma can be generated only within the processing chamber without generating plasma within the vacuum chamber, thereby increasing the plasma intensity within the processing chamber.

[0012] In addition, it is preferable that the plasma processing apparatus has a cooling passage formed in the stage through which a cooling fluid flows, so that the stage can be cooled by the cooling fluid, thereby cooling the workpiece placed on the stage.

[0013] In addition, in the plasma processing apparatus, it is preferable that the insulating container has a shape that opens downward, the workpiece is attached in contact with the stage, and the insulating container is placed on the stage so as to cover the workpiece. In this way, the workpiece is attached in contact with the stage that is cooled by a cooling fluid, so that heat can be efficiently removed from the workpiece.

[0014] Furthermore, in the plasma processing apparatus, it is preferable that the insulating container has a shape that opens downward, the stage has a communication hole that connects the processing chamber and the vacuum chamber, and the vacuum chamber and the processing chamber are evacuated by a common vacuum exhaust device. In this way, the vacuum chamber and the processing chamber can be evacuated at the same time by a single vacuum exhaust device, thereby simplifying the device configuration.

[0015] In addition, it is preferable that the plasma processing apparatus further includes an aperture adjustment plate that is disposed on the rear side of the stage and has through holes formed therein at positions corresponding to the communication holes of the stage, and that the aperture adjustment plate is moved relative to the stage to adjust the aperture of the communication hole formed in the stage. In this way, it is possible to adjust the degree of overlap between the communication holes of the stage and the through holes of the aperture adjustment plate, for example by rotating the aperture adjustment plate, thereby adjusting the aperture of the communication hole and thereby adjusting the pressure in the processing chamber.

[0016] In addition, in the plasma processing apparatus, it is preferable that the stage has a circular shape in a plan view, and the aperture of the communication hole of the stage is adjusted by rotating the aperture adjustment plate around the center of the stage as a rotation axis, thereby making it possible to easily adjust the pressure in the processing chamber by simply rotating the aperture adjustment plate.

[0017] In a specific embodiment of the plasma processing apparatus, the antenna is disposed so as to surround the side circumferential surface of the insulating container, and by disposing the antenna so as to surround the processing chamber, the distribution of plasma within the processing chamber can be made uniform, thereby reducing unevenness in the plasma processing of the tool.

[0018] Furthermore, in the plasma processing apparatus, it is preferable that the processing chamber formed by the insulating container is divided into a plasma generation chamber around which the antenna is arranged to generate plasma, and a plasma processing chamber that houses the workpiece and performs plasma processing on the workpiece. By dividing the processing chamber into a plasma generation chamber and a plasma processing chamber, it is possible to prevent, for example, coatings removed from tools by plasma processing from adhering to and contaminating the walls of the plasma generation chamber. This reduces the decrease in the intensity of the generated plasma compared to when plasma generation and plasma processing are performed simultaneously in the same space within the processing chamber, allowing for stable plasma processing.

[0019] In this case, it is preferable that the antenna is disposed so as to surround only the plasma generation chamber without surrounding the plasma processing chamber, and the object to be processed is accommodated in the plasma processing chamber. In this way, by preventing the plasma generation space and the plasma processing space from overlapping, the decrease in the intensity of the generated plasma can be further suppressed, and more stable plasma processing can be achieved.

[0020] The plasma processing method of the present invention is a method for plasma processing the surface of a workpiece, which is a tool placed on a stage installed in a vacuum chamber formed by a vacuum container, using plasma, and is characterized in that an insulating container forming a processing chamber that contains the workpiece is placed on the stage, and plasma is generated in the processing chamber by an antenna arranged around the insulating container in the vacuum chamber, thereby plasma processing the surface of the workpiece.

[0021] Such a plasma processing method can achieve the same effects as the plasma processing apparatus of the present invention described above.

[0022] According to the present invention configured in this manner, in a plasma processing apparatus that uses plasma to process the surface of a tool, even if the tool is heavy, such as a hob, it is possible to efficiently suppress the temperature rise of the tool during plasma processing with an inexpensive configuration, and to perform film removal processing and film formation processing uniformly.

[0023] FIG. 1 is a cross-sectional view schematically showing the configuration of a plasma processing apparatus according to one embodiment of the present invention; FIG. 2 is a top view schematically showing the configuration of the plasma processing apparatus according to the same embodiment; FIG. 3 is a top view schematically showing the configuration of a stage according to the same embodiment; FIG. 4 is a view explaining an opening adjustment mechanism according to the same embodiment; FIG. 5 is a view explaining an opening adjustment mechanism according to the same embodiment; FIG. 6 is a cross-sectional view schematically showing the configuration of a plasma processing apparatus according to another embodiment; FIG. 7 is a cross-sectional view schematically showing the configuration of a conventional plasma processing apparatus; and FIG. 8 is a top view schematically showing the configuration of a conventional plasma processing apparatus.

[0024] A plasma processing apparatus 100 according to one embodiment of the present invention will be described below with reference to the drawings.

[0025] <Apparatus Configuration> The plasma processing apparatus 100 of this embodiment removes a hard coating formed on the surface of a tool T by plasma processing using inductively coupled plasma.

[0026] 1 and 2 , the plasma processing apparatus 100 includes a vacuum vessel 1 forming a vacuum chamber 1s, an antenna 2 provided in the vacuum chamber 1s, a high-frequency power supply 3 for applying high-frequency waves to the antenna 2, a gas supply mechanism 4 for supplying plasma generating gas to the vacuum chamber 1s, a stage 5 installed in the vacuum chamber 1s, and a bias power supply 6 for applying a bias voltage to the stage 5. In the plasma processing apparatus 100 configured as described above, a number of tools T as workpieces are placed on the stage 5, and by supplying plasma generating gas to the vacuum chamber 1s and applying a high-frequency current to the antenna 2, an inductive electric field is generated within the vacuum chamber 1s, generating inductively coupled plasma. Then, by applying a bias voltage to the stage 5 from the bias power supply 6, positive ions in the plasma are incident on the coatings on the surfaces of the tools T, thereby enabling the surfaces of a number of tools T to be simultaneously delaminated.

[0027] The tool T to be processed by the plasma processing apparatus 100 of this embodiment is a so-called coated tool, which is a tool having a film (also called a coating film) formed on the surface of a substrate made of tool steel or cemented carbide, specifically a hob. Note that the tool T to be processed is not limited to a hob, and may be another tool such as a drill.

[0028] The vacuum vessel 1 is a metal vessel. The vacuum vessel 1 is electrically grounded, and the vacuum chamber 1s therein is evacuated by a vacuum pumping device V.

[0029] The gas supply mechanism 4 includes a gas source (not shown) and a gas pipe 41 connected to the gas source and equipped with a flow rate regulator (not shown), and supplies a plasma generating gas with a regulated flow rate into the vacuum vessel 1 through the gas pipe 41. The gas pipe 41 penetrates the side wall (here, the upper wall) of the vacuum vessel 1, and its downstream end 41a opens into the vacuum chamber 1s. The gap between the gas pipe 41 and the bottom wall is sealed with an insulating sealing member.

[0030] The plasma generating gas is, for example, a rare gas such as argon gas, a halogen gas, or a mixture thereof, and may be changed appropriately depending on the material of the coating to be removed.

[0031] One end of the antenna 2, which is the power supply end, is connected to the high frequency power supply 3 via a matching box 31 equipped with a matching circuit, and the other end, which is the terminal end, is grounded via the matching box 31. Both ends of the antenna 2 penetrate the side walls of the vacuum vessel 1. An insulating member is provided at the penetration portion of the vacuum vessel 1 where the antenna 2 penetrates, and this penetration portion is vacuum sealed by, for example, packing.

[0032] The material of the antenna 2 is, for example, but not limited to, copper, aluminum, an alloy of these, stainless steel, etc. The antenna 2 may be hollow and a refrigerant such as cooling water may be passed through it to cool the antenna 2.

[0033] The high frequency power supply 3 can supply a high frequency current to the antenna 2 via a matching circuit. The frequency of the high frequency is, for example, a common 13.56 MHz, but is not limited to this and may be changed as appropriate.

[0034] 2 and 3, the stage 5 is made of metal and has a generally circular disk shape, and includes a circular tool placement surface 51 on which a plurality of tools T are placed and which holds the tools T. The tool placement surface 51 is provided with a plurality of (eight in this example) holding portions 52 arranged concentrically and at equal intervals, each holding a tool T in an upright state with its rotation axis aligned vertically.

[0035] A metal shaft 5s is connected to the center of the axis on the underside of the stage 5. This shaft 5s passes through the bottom wall of the vacuum vessel 1. The space between the shaft 5s and the bottom wall is sealed by an insulating sealing member.

[0036] The bias power supply 6 is connected to the shaft 5s and applies a bias voltage to the stage 5 via the shaft 5s. The bias voltage may be, for example, but is not limited to, a negative DC voltage. This bias voltage controls the energy of positive ions in the plasma when they strike the coating on the surface of the tool T, thereby controlling the rate at which the coating is removed.

[0037] Thus, the plasma processing apparatus 100 of this embodiment is provided with an insulating container 7 that is disposed on a stage 5 and forms a processing chamber 7s on the stage 5 for accommodating a tool T as an object to be processed, and the antenna 2 is disposed around the insulating container 7, and an inductively coupled plasma is generated in the processing chamber 7s formed by the insulating container 7. That is, in the plasma processing apparatus 100 of this embodiment, a smaller processing chamber 7s is formed across a space within the vacuum chamber 1s formed by the vacuum container 1.

[0038] The insulating container 7 in this embodiment is hollow and opens downward, with an opening formed at the bottom. The insulating container 7 is placed on the tool mounting surface 51 with the openings facing each other, and the inner wall surface of the insulating container 7 and the tool mounting surface 51 form a processing chamber 7s having a substantially circular cross section. That is, a tool T is attached to the tool mounting surface 51 of the stage 5 in contact with the tool T via a holder 52, and the insulating container 7 is placed on the tool mounting surface 51 so as to cover the tool T. It is preferable, but not limited to, that the gap between the bottom of the placed insulating container 7 and the tool mounting surface 51 of the stage 5 be hermetically sealed with a seal member.

[0039] The insulating container 7 is made of a material, partly or entirely, that is insulating and allows the high-frequency magnetic field generated by the antenna 2 to pass through into the processing chamber 7s, and is made of, for example, ceramics such as alumina, silicon carbide, silicon nitride, etc., inorganic materials such as quartz glass, non-alkali glass, etc.

[0040] The gas pipe 41 of the gas supply mechanism 4 described above penetrates the side wall (here, the upper wall) of the insulating container 7, and its downstream end 41 a opens into the processing chamber 7 s, so that the plasma generating gas supplied from the gas source is directly introduced into the processing chamber 7 s.

[0041] Furthermore, in the region R of the tool mounting surface 51 covered by the insulating container 7 (i.e., the region R forming the processing chamber 7s), a communication hole 5h is formed that penetrates the stage 5 in the thickness direction and connects the processing chamber 7s to the vacuum chamber 1s. That is, one end of this communication hole 5h opens to the processing chamber 7s and the other end opens to the vacuum chamber 1s. As shown in FIG. 3 , a plurality of communication holes 5h are formed in the region R, and more specifically, they are formed in a concentric pattern at equal intervals around the holding portion 52. By connecting the vacuum chamber 1s and the processing chamber 7s through the communication holes 5h in this manner, the vacuum chamber 1s and the processing chamber 7s are evacuated by a common vacuum exhaust device V.

[0042] The antenna 2 is arranged to surround the side circumferential surface of the insulating container 7. More specifically, the antenna 2 is arranged to surround the side circumferential surface of the tool T standing on the tool placing surface 51 from the upper end to the lower end via the insulating container 7.

[0043] In this embodiment, a plurality of insulating containers 7 are arranged concentrically at equal intervals on the stage 5, and each insulating container 7 is individually arranged for each of the plurality of tools T. In other words, one insulating container 7 is arranged for one tool T.

[0044] The plasma processing apparatus 100 of this embodiment includes a plurality of antennas 2, each of which is individually disposed around a respective one of a plurality of insulating containers 7. Some or all of the plurality of antennas 2 may be connected to a common high-frequency power supply 3, or all of the antennas 2 may be connected to different high-frequency power supplies 3.

[0045] With this configuration, when a high frequency is applied to each antenna 2 from the high frequency power supply 3, the high frequency magnetic field generated from each antenna 2 is supplied to the processing chamber 7s through the side wall of each insulating container 7. As a result, an inductive electric field is generated in each processing chamber 7s, generating inductively coupled plasma, and coatings are removed from the tools T placed in each processing chamber 7s.

[0046] Furthermore, the plasma processing apparatus 100 of this embodiment is provided with a cooling mechanism 8 that cools the workpiece, that is, the tool T. This cooling mechanism 8 cools the tool mounting surface 51 of the stage 5, thereby cooling the tool T that is placed in contact with the tool mounting surface 51.

[0047] Specifically, the cooling mechanism 8 includes a cooling passage 81 formed in the stage 5 and a fluid distribution mechanism (not shown), such as a chiller, that circulates a cooling fluid, such as water, through the cooling passage 81. By flowing the cooling fluid through the cooling passage 81 using the fluid distribution mechanism, the temperature of the entire stage 5 is lowered, and the entire tool mounting surface 51 becomes a cooled surface. As shown in FIG. 1 , the cooling passage 81 is formed inside the stage 5 in a direction parallel to the tool mounting surface 51. Note that this cooling passage 81 is also formed inside the shaft 5s, allowing the cooling fluid to circulate inside and outside the vacuum chamber 1s.

[0048] Furthermore, the plasma processing apparatus 100 of this embodiment is equipped with an aperture adjustment mechanism 9 that adjusts the aperture of the communication hole 5h formed in the stage 5. This aperture adjustment mechanism 9 is arranged in contact with the flat back surface of the stage 5 and includes an aperture adjustment plate 91 that is rotatable about the center (center of gravity) of the stage 5, and an actuator 92 that rotates the aperture adjustment plate 91. The operation of this aperture adjustment mechanism 9 is controlled by a control unit (not shown).

[0049] The aperture adjustment plate 91 has an annular shape surrounding the shaft 5s and has through holes (referred to as adjustment holes 91h) formed therein that penetrate the plate in its thickness direction. The aperture adjustment plate 91 has a plurality of adjustment holes 91h formed therein, and the plurality of adjustment holes 91h are formed to have the same arrangement pattern (hole arrangement) as the plurality of communication holes 5h formed in the stage 5. In other words, in a certain aspect, the positions of the plurality of communication holes 5h formed in the stage 5 and the positions of the plurality of adjustment holes 91h formed in the aperture adjustment plate 91 are configured to coincide with each other.

[0050] The actuator 92 includes a drive wheel that contacts the side surface of the opening adjustment plate 91 and a motor (not shown) that rotates the drive wheel. By rotating the motor forward or backward to rotate the drive wheel, the opening adjustment plate 91 rotates forward or backward around the center of the stage 5 as the rotation axis.

[0051] Specifically, the aperture adjustment plate 91 is rotationally driven by an actuator 92, and is rotatably movable between (a) a fully open position, (b) an intermediate position, and (c) a fully closed position, as shown in Figures 4 and 5. (a) The fully open position is a position where all of the communication holes 5h formed in the stage 5 and all of the adjustment holes 91h formed in the aperture adjustment plate 91 are aligned. (b) The intermediate position is a position where some areas of the communication holes 5h formed in the stage 5 face the adjustment holes 91h formed in the aperture adjustment plate 91, and the remaining areas are blocked by the plate surface of the aperture adjustment plate 91. (c) The fully closed position is a position where all of the communication holes 5h formed in the stage 5 are blocked by the plate surface of the aperture adjustment plate 91.

[0052] <Effects of this embodiment> According to the plasma processing apparatus 100 of this embodiment configured as described above, a small processing chamber 7s isolated by an insulating container 7 is formed above the stage 5 in the vacuum chamber 1s, and the tool T is housed in the processing chamber 7s, and plasma is generated to perform plasma processing. This allows a large ratio of the number of antennas 2 generating plasma to the number of tools T to be processed, and therefore allows uniform plasma processing of the workpieces without rotating the stage 5. Furthermore, since a rotation mechanism is not required for the stage 5, the structure can be simplified, and a cooling structure such as water cooling can be formed within the stage 5, for example, and the temperature rise of the tool T during plasma processing can be efficiently suppressed.

[0053] <Other Modified Embodiments> The present invention is not limited to the above-described embodiments. For example, the plasma processing apparatus 100 in the above-described embodiments functions as a film removal apparatus that removes a coating from the tool T using plasma, but the present invention is not limited to this. In other embodiments, the plasma processing apparatus 100 may function as a film formation apparatus that forms a coating on the surface of the tool T using plasma. In this case, for example, a sputtering target may be provided inside the insulating container 7, and a bias voltage may be applied to the sputtering target.

[0054] In the above embodiment, the stage 5 has a circular shape, but this is not limiting. In other embodiments, the stage 5 may have a shape other than a circle, such as a rectangular shape. In still other embodiments, the insulating container 7 and the tools T do not have to be concentrically arranged on the stage 5, and they do not have to be arranged at equal intervals. In still other embodiments, plasma processing may be performed in which multiple tools T are housed in a single insulating container 7.

[0055] Furthermore, the communication hole 5h formed in the stage 5 does not have to be formed so as to penetrate through in the thickness direction, as long as one end opens to the processing chamber 7s and the other end opens to the vacuum chamber 1s. For example, the other end of the communication hole 5h may be formed so as to open to the side peripheral surface of the stage 5.

[0056] In another embodiment, the antenna 2 does not have to be provided individually for each of the multiple insulating containers 7. For example, one antenna 2 may be provided for the multiple insulating containers 7. In another embodiment, the antenna 2 may be provided inside the insulating container 7 rather than outside the insulating container 7.

[0057] In still another embodiment, the plasma processing apparatus 100 does not necessarily have to include the cooling mechanism 8 and the opening degree adjusting mechanism 9 .

[0058] Furthermore, in the above embodiment, the antenna 2 is disposed around the side surface of the tool placed on the tool mounting surface 51 from top to bottom via the insulating container 7, and plasma generation and plasma processing (film removal or film formation) are simultaneously performed in the processing chamber 7s. However, this is not limited to this. In other embodiments, as shown in FIG. 6 , the processing chamber 7s formed by the insulating container 7 may be divided into a plasma generation chamber 7s1 where plasma is generated and a plasma processing chamber 7s2 where plasma processing is performed. In this case, the plasma generation chamber 7s1 and the plasma processing chamber 7s2 are adjacent and spatially connected, and the plasma generation chamber 7s1 is preferably formed upstream of the plasma processing chamber 7s2. That is, the downstream end 41a of the gas pipe 41 of the gas supply mechanism 4 preferably opens into the plasma generation chamber 7s1, and the end of the communication hole 5h formed in the stage 5 preferably opens into the plasma processing chamber 7s2. Furthermore, the plasma generation chamber 7s1 and the plasma processing chamber 7s2 are preferably partially separated by the inner wall of the insulating container 7. The antenna 2 is preferably disposed so as to surround only the plasma generation chamber 7s1 without surrounding the plasma processing chamber 7s2, and the tool T is preferably housed within the plasma processing chamber 7s2.

[0059] In the above embodiment, the plasma processing is performed using inductively coupled plasma, but this is not limiting. In other embodiments, the plasma processing may be performed using plasma generated by other methods, such as capacitively coupled plasma. That is, in other embodiments, the plasma source does not have to be configured using the antenna 2 and the high-frequency power supply 3.

[0060] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0061] According to the present invention, in a plasma processing apparatus that uses plasma to process the surface of a tool, even if the tool is heavy, such as a hob, the temperature rise of the tool during plasma processing can be efficiently suppressed with an inexpensive configuration, and film removal processing and film formation processing can be performed uniformly.

[0062] REFERENCE SIGNS LIST 100: Plasma processing apparatus 1: Vacuum vessel 1s: Vacuum chamber 2: Antenna 5: Stage 7: Insulating vessel 7s: Processing chamber T: Tool

Claims

1. A plasma processing apparatus for plasma processing the surface of a workpiece, which is a tool, using plasma, comprising: a vacuum vessel forming a vacuum chamber; a stage installed within the vacuum chamber; an insulating vessel arranged on the stage to form a processing chamber for accommodating the workpiece; and an antenna arranged around the insulating vessel within the vacuum chamber to generate plasma within the processing chamber.

2. A plasma processing apparatus according to claim 1, which performs plasma processing on the surfaces of a plurality of workpieces at once, and which comprises a plurality of insulating containers and a plurality of antennas arranged around each of the insulating containers.

3. The plasma processing apparatus according to claim 2, wherein the plurality of insulating containers are individually provided for each of the plurality of objects to be processed.

4. A plasma processing apparatus according to claim 1, further comprising a gas supply mechanism for supplying a plasma generating gas into the insulating container, the gas supply mechanism comprising: a gas source; and a gas pipe having an upstream end connected to the gas source through which the plasma generating gas flows and a downstream end opening into the insulating container.

5. The plasma processing apparatus according to claim 1, wherein a cooling flow path through which a cooling fluid flows is formed within said stage.

6. The plasma processing apparatus according to claim 5, wherein the insulating container has a shape that opens downward, the object to be processed is attached in contact with the stage, and the insulating container is placed on the stage so as to cover the object to be processed.

7. The plasma processing apparatus according to claim 1, wherein the insulating container has a shape that opens downward, the stage is formed with a communication hole that connects the processing chamber and the vacuum chamber, and the vacuum chamber and the processing chamber are evacuated by a common vacuum exhaust device.

8. A plasma processing apparatus as described in claim 7, wherein the stage is plate-shaped, the communicating holes are formed in the stage so as to penetrate in the thickness direction, and the apparatus further comprises an aperture adjustment plate disposed on the rear side of the stage and having through holes formed in positions corresponding to the through holes of the stage, and the aperture of the communicating holes formed in the stage is adjusted by moving the aperture adjustment plate relative to the stage.

9. A plasma processing apparatus according to claim 8, wherein the stage has a circular shape in a plan view, and the opening of the communication hole of the stage is adjusted by rotating the opening adjustment plate around the center of the stage as a rotation axis.

10. A plasma processing apparatus according to claim 1, wherein said antenna is disposed so as to surround the side periphery of said insulating container.

11. The plasma processing apparatus according to claim 1, wherein the processing chamber formed by the insulating container is divided into a plasma generation chamber around which the antenna is arranged to generate plasma, and a plasma processing chamber that contains the object to be processed and in which plasma processing is performed on the object to be processed.

12. The plasma processing apparatus according to claim 11, wherein the antenna is disposed so as to surround only the plasma generation chamber without surrounding the plasma processing chamber, and the object to be processed is accommodated in the plasma processing chamber.

13. A method for plasma processing the surface of a workpiece, which is a tool placed on a stage installed in a vacuum chamber formed by a vacuum container, using plasma, comprising: placing an insulating container forming a processing chamber for accommodating the workpiece on the stage; generating plasma in the processing chamber by an antenna arranged around the insulating container within the vacuum chamber, and plasma processing the surface of the workpiece.

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