KR102322816B1 - Plasma processing apparatus - Google Patents

Abstract

[Problem] Stabilize plasma discharge even when processing a workpiece containing an insulating material.
[Solutions] In the plasma processing apparatus, an opening 11 is formed at one end, a cylindrical electrode 10 into which a process gas is introduced, and an RF power source 15 for applying a voltage to the cylindrical electrode 10 . and a rotary table 3 as a conveying unit for conveying the workpiece W and passing the work W through the lower portion of the opening 11 , and an electromagnetic induction member 17 disposed between the opening 11 and the rotary table 3 . do.

Description

Plasma processing apparatus {PLASMA PROCESSING APPARATUS}

The present invention relates to a plasma processing apparatus.

In the manufacturing process of various products, such as a semiconductor device, a liquid crystal display, or an optical disk, thin films, such as an optical film, may be formed into a film, for example on a workpiece|work, such as a wafer and a glass substrate. A thin film can be created by repeating film formation for forming a film of a metal or the like on a work, and film processing such as etching, oxidation or nitriding on the formed film.

Although film formation and film processing can be performed by various methods, there is one using plasma as one of them. In film-forming, an inert gas is introduce|transduced into the vacuum container in which the target is arrange|positioned, and a DC voltage is applied. Plasma-formed inert gas ions are made to collide with a target, and the material which has been beaten out from the target is deposited on the work to form a film. In the film treatment, a process gas is introduced into a vacuum container in which an electrode is disposed, and a high-frequency voltage is applied to the electrode. The film treatment is performed by making plasma-ized process gas ions collide with the film on the work.

A plasma processing apparatus in which a rotary table is attached to the inside of one vacuum container and a plurality of film-forming units and film-processing units are arranged in the circumferential direction above the rotary table so that such film formation and film processing can be performed continuously There is (for example, refer to patent document 1). An optical film or the like is formed by carrying the work while holding it on a rotary table and passing it directly under the film forming unit and the film processing unit.

In a plasma processing apparatus using a rotary table, a cylindrical electrode (hereinafter, referred to as a "tubular electrode") having a closed upper end and an opening at the lower end may be used as a film processing unit. In such a film processing unit, the cylindrical electrode serves as the anode, and the rotary table positioned below the opening of the cylindrical electrode serves as the cathode. Plasma is generated by introducing a process gas into the cylindrical electrode and applying a high-frequency voltage. Electrons included in the generated plasma flow into the rotating table, which is a cathode. By passing the work held on the rotary table under the opening of the cylindrical electrode, ions contained in the plasma collide with the work, and the film treatment is performed.

Patent Document 1: Japanese Patent Laid-Open No. 2002-256428

The work conveyed to the rotary table may contain an insulating material. When the work including the insulator is positioned under the cylindrical electrode, the insulator is included in the cathode. As a result, it becomes difficult for electrons of the plasma to flow to the cathode side, the plasma becomes unstable, and there is a fear that the film treatment may not be performed properly.

Here, the RF power supply which applies a high frequency voltage to the cylindrical electrode is connected to the cylindrical electrode and a vacuum container via a matching box. Even in a state in which the workpiece is positioned under the cylindrical electrode, the plasma can be stabilized by matching the impedance of the input side and the output side by means of a matching box.

However, in order to improve the processing efficiency, as many workpieces as possible are placed on the rotary table. When the gap between the workpieces becomes narrow, the state in which the insulator is not contained and the state in which the cathode is contained are drastically changed. In this case, there is a possibility that the adjustment of the impedance in the matching box does not match the time. As a result, the plasma discharge becomes unstable, and there is a fear that the quality of the film treatment is affected.

In order to solve the above problems, the present invention provides a plasma processing apparatus capable of improving processing efficiency without being influenced by the state of the workpiece by stabilizing plasma discharge even when processing a workpiece containing an insulating material. aim to do

In order to achieve the above object, in the plasma processing apparatus of the present invention, an opening is formed at one end of a cylindrical electrode into which a process gas is introduced; A carrying portion that passes under the opening portion, and an electromagnetic induction member disposed between the opening portion and the carrying portion are provided.

The electromagnetic induction member may be a ring-shaped member having a hole in the center.

The electromagnetic induction member may be a plate-shaped member that traverses a central portion of the opening portion in a direction orthogonal to the transport direction of the transport unit.

The conveying unit has a rotary table disposed in a vacuum container to hold and circulately convey a work, the cylindrical electrode is disposed above a holding position of the work of the rotary table, and the plasma processing apparatus includes the electromagnetic induction A support member for supporting the member between the opening and the rotary table may be further provided.

The support member is installed upright from the bottom near the outer periphery of the vacuum vessel and extends just below the cylindrical electrode, and an outer support for supporting the electromagnetic induction member between the rotary table and the cylindrical electrode You may make it include a member.

It is installed standing up inside the vacuum container, and the tip portion further includes a post penetrating the center of the rotary table, the rotary table is rotatably supported on the post through a rolling bearing, and the support member includes: , an inner support member attached to the post and extending just below the cylindrical electrode to support the electromagnetic induction member between the rotary table and the cylindrical electrode.

The electromagnetic induction member may be connected to the tip of the cylindrical electrode via an insulating material.

The electromagnetic induction member may cover an area of 50% to 85% of the opening.

The electromagnetic induction member may contain a conductive member and an etching inhibitor, antioxidant or nitridation inhibitor coated on the conductive member.

By disposing the electromagnetic induction member between the opening of the cylindrical electrode and the conveying part of the work, the electrons generated in the plasma can be induced to the electromagnetic inducing member without affecting the property or conveying state of the work conveyed by the conveying unit, Plasma discharge can be stabilized. By stabilizing the plasma discharge, ions, radicals, etc. generated in the plasma reach the workpiece stably. As a result, it is possible to provide a plasma processing apparatus capable of improving processing efficiency and providing products with stable quality.

1 is a plan view schematically showing the configuration of a plasma processing apparatus according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 .
FIG. 3 is a cross-sectional view taken along line BB of FIG. 1 , and is a view of the membrane processing unit viewed from the center of the rotary table.
4 is a plan view of the membrane processing unit.
5 is a graph showing test results.
6 is a plan view of a film processing unit of a plasma processing apparatus according to another embodiment of the present invention.
7 is a view of the film processing unit of the plasma processing apparatus according to another embodiment of the present invention as viewed from the center of the rotary table.

[Configuration]

EMBODIMENT OF THE INVENTION Embodiment of this invention is described concretely with reference to drawings.

As shown in Figs. 1 and 2, the plasma processing apparatus has a chamber 1 having a substantially cylindrical shape. An exhaust part 2 is provided in the chamber 1, so that the inside of the chamber 1 can be exhausted by vacuum. That is, the chamber 1 functions as a vacuum container. A hollow rotating shaft 3b penetrates the bottom of the chamber 1 and is erected inside the chamber 1 . A substantially circular rotary table 3 is attached to the rotary shaft 3b. A drive mechanism (not shown) is connected to the rotation shaft 3b. By driving the drive mechanism, the rotary table 3 rotates about the rotary shaft 3b. An immovable post 3c is arranged inside the hollow rotating shaft 3b. The post 3c is fixed to a base (not shown) provided outside the chamber 1 , penetrates the bottom of the chamber 1 , and is erected inside the chamber 1 . An opening is formed in the center of the rotary table 3 . The post 3c passes through the opening of the rotary table 3 , and the tip is positioned between the upper surface of the rotary table 3 and the upper surface of the chamber 1 . Here, the tip of the post 3c may be in contact with the upper surface of the chamber 1 . A ball bearing 3d is disposed between the opening of the rotary table 3 and the post 3c. That is, the rotary table 3 is rotatably supported by the post 3c via the ball bearing 3d.

Since the chamber 1, the rotary table 3, and the rotary shaft 3b act as a cathode in the plasma processing apparatus, they may be constituted of a conductive metal member with low electrical resistance. The rotary table 3 may be made of, for example, a metal such as aluminum, stainless steel, or copper. In addition, as the rotary table 3, what sprayed aluminum oxide on the surface of the plate-shaped member of stainless steel may be used. Although aluminum oxide is an insulator, in the case of high-frequency plasma, if the thickness of aluminum oxide is within a range where impedance matching is obtained in the matching box, plasma can be formed. When the aluminum oxide is thermally sprayed in this way, the rotary table 3 is difficult to be etched by plasma, and the etched particles are prevented from adhering to the work W or the inner wall of the chamber 1, and particles can be reduced.

A plurality of holding portions 3a for holding the work W are provided on the upper surface of the rotary table 3 . The plurality of holding portions 3a are provided at equal intervals along the circumferential direction of the rotary table 3 . When the rotary table 3 rotates, the work W held by the holding portion 3a moves in the circumferential direction of the rotary table 3 . In other words, on the surface of the rotary table 3, a conveyance path (hereinafter referred to as a "conveyance path P") which is a circular movement trajectory of the work W is formed. The holding part 3a can be set as the tray which arrange|positions the workpiece|work W, for example. When the tray is, for example, of a type capable of arranging two workpieces W, as shown in FIG. 3 , the gap between the two workpieces W disposed on the same tray is equal to that of the workpieces disposed on different trays. It becomes narrower than the gap between (W).

Hereinafter, simply referred to as "the circumferential direction" means "the circumferential direction of the rotary table 3", and simply referred to as "radial direction" means "radial direction of the rotary table 3". Moreover, in this embodiment, although the flat board|substrate is used as an example of the workpiece|work W, the kind, shape, and material of the workpiece|work W to which plasma processing is performed are not limited to a specific thing. For example, you may use a curved board|substrate which has a recessed part or a convex part at the center. In addition, those containing a conductive material such as metal or carbon, those containing an insulating material such as glass or rubber, or those containing a semiconductor such as silicon may be used.

Above the rotary table 3, a unit (hereinafter, referred to as a “processing unit”) for processing each process in the plasma processing apparatus is provided. The respective processing units are disposed adjacent to each other at a predetermined distance from each other along the conveyance path P of the workpiece W formed on the surface of the rotary table 3 . The process of each process is made|formed by the workpiece|work W hold|maintained by the holding|maintenance part 3a passing under each processing unit.

In the example of FIG. 1 , seven processing units 4a to 4g are arranged along the conveyance path P on the rotary table 3 . In the present embodiment, the processing units 4a , 4b , 4c , 4d , 4f , and 4g are film-forming units that perform a film-forming process on the work W . The processing unit 4e is a film processing unit that processes the film formed on the work W by the film forming unit. In this embodiment, the film-forming unit demonstrates assuming that sputtering is performed. In addition, the film processing unit 4e is demonstrated on the assumption that post-oxidation is performed. Here, the post-oxidation is a process for oxidizing the metal film by introducing oxygen ions or the like generated by plasma into the metal film formed by the film forming unit. Between the processing unit 4a and the processing unit 4g, an unprocessed workpiece W is brought into the chamber 1 from the outside, and the processed workpiece W is transported out of the chamber 1 . A load lock unit 5 is provided. In addition, in this embodiment, let the conveyance direction of the workpiece|work W be the direction toward the processing unit 4g from the position of the processing unit 4a in a clockwise direction in FIG. Of course, this is an example, and the conveyance direction, the kind of processing unit, the arrangement order, and the number are not limited to a specific thing, and can be determined suitably.

The structural example of the processing unit 4a which is a film-forming unit is shown in FIG. The other film-forming units 4b, 4c, 4d, 4f, and 4g may be configured in the same manner as the film-forming unit 4a, but other structures may be applied. As shown in FIG. 2, the film-forming unit 4a is equipped with the target 6 adhered to the upper surface inside the chamber 1 as a sputtering source. The target 6 is a plate-shaped member made of a material to be deposited on the work W. The target 6 is provided in the position opposite to the work W, when the work W passes under the film-forming unit 4a. A DC power supply 7 for applying a DC voltage to the target 6 is connected to the target 6 . Further, a sputtering gas introduction unit 8 for introducing a sputtering gas into the interior of the chamber 1 is provided in the vicinity of the portion where the target 6 is attached on the upper surface of the chamber 1 . As the sputtering gas, an inert gas such as argon can be used. A barrier rib 9 for reducing the outflow of plasma is provided around the target 6 . In this case, as the power source, well-known ones such as a DC pulse power supply and an RF power supply can be applied.

The structural example of the film|membrane processing unit 4e is shown in FIG.2 and FIG.3. The film processing unit 4e is provided with an electrode (hereinafter, referred to as a “cylindrical electrode”) 10 installed on the upper surface of the chamber 1 and formed in a cylindrical shape. The cylindrical electrode 10 has an angular cylindrical shape, has an opening 11 at one end, and is closed at the other end. The cylindrical electrode 10 penetrates through a through hole formed in the upper surface of the chamber 1 , and the end of the opening 11 side is located inside the chamber 1 , and the closed end is located outside the chamber 1 . are placed The cylindrical electrode 10 is supported on the periphery of the through hole of the chamber 1 via an insulating material. The opening 11 of the cylindrical electrode 10 is arrange|positioned at the position facing the conveyance path P formed on the turn table 3 . That is, the rotary table 3 passes just below the opening part 11 while circulatingly conveying the workpiece|work W as a conveyance part. And the position just below the opening part 11 becomes the passage position of the workpiece|work W. As shown in FIG.

As shown in FIG. 1 , the cylindrical electrode 10 has a sectoral shape extending outward from the center side in the radial direction of the rotary table 3 when viewed from above. The fan shape as used herein means the shape of the fan side part of the fan. The opening 11 of the cylindrical electrode 10 is similarly sector-shaped. The speed at which the workpiece W held on the rotary table 3 passes under the opening 11 becomes slower toward the center in the radial direction of the rotary table 3, and becomes faster toward the outside. Therefore, if the opening 11 is a simple rectangle or a square, a difference occurs in the time for the workpiece W to pass just below the opening 11 from the center side and the outside in the radial direction. By expanding the diameter of the opening 11 from the center side to the outside in the radial direction, the time for the workpiece W to pass through the opening 11 can be made constant, and the plasma treatment described later can be made uniform. . However, a rectangle or a square may be sufficient as long as the difference in passing time does not become a problem on a product.

As described above, the cylindrical electrode 10 penetrates the through hole of the chamber 1 , and a part thereof is exposed to the outside of the chamber 1 . A portion of the cylindrical electrode 10 exposed to the outside of the chamber 1 is covered with an external shield 12 as shown in FIG. 2 . The space inside the chamber 1 is kept airtight by the outer shield 12 . The periphery of the portion located inside the chamber 1 of the cylindrical electrode 10 is covered by the inner shield 13 .

The inner shield 13 has an angular cylindrical shape coaxial with the cylindrical electrode 10 , and is supported on the upper surface inside the chamber 1 . Each side surface of the cylinder of the inner shield 13 is provided substantially parallel to each side surface of the cylinder electrode 10 . The lower end of the inner shield 13 is at the same height as the opening 11 of the cylindrical electrode 10, but at the lower end of the inner shield 13, a flange extending parallel to the upper surface of the rotary table 3 ( 14) is provided. The flange 14 suppresses the plasma generated inside the cylindrical electrode 10 from flowing out of the inner shield 13 . The workpiece W conveyed by the rotary table 3 passes through the gap between the rotary table 3 and the flange 14 , and is carried in directly under the opening 11 of the cylindrical electrode 10 , and again the rotary table It passes through the gap between (3) and the flange 14, and is carried out just below the opening part 11 of the cylindrical electrode 10. As shown in FIG.

An RF power supply 15 for applying a high-frequency voltage is connected to the cylindrical electrode 10 . A matching box 21 as a matching circuit is connected in series to the output side of the RF power source 15 . The RF power supply 15 is also connected to the chamber 1 . A cylindrical electrode 10 is an anode, and a rotary table 3 installed standing up from the chamber 1 acts as a cathode. The matching box 21 stabilizes the plasma discharge by matching the impedances of the input side and the output side. In addition, the chamber 1 and the rotary table 3 are grounded. The inner shield 13 with flange 14 is also grounded.

In addition, a process gas introduction part 16 is connected to the cylindrical electrode 10 , and a process gas is introduced into the cylindrical electrode 10 from an external process gas supply source through the process gas introduction part 16 . The process gas can be appropriately changed according to the purpose of the film treatment. For example, in the case of etching, an inert gas such as argon can be used as the etching gas. Oxygen can be used when performing oxidation treatment or post-oxidation treatment. When nitriding is performed, nitrogen can be used. The RF power source 15 and the process gas introduction unit 16 are connected together to the cylindrical electrode 10 through a through hole formed in the outer shield 12 .

An electromagnetic induction member 17 is provided between the opening 11 of the cylindrical electrode 10 and the rotary table 3 . An example of the electromagnetic induction member 17 is shown in FIG. The electromagnetic induction member 17 is a ring-shaped member having a hole portion 17a in the center. The external shape of the electromagnetic induction member 17 and the shape of the central hole 17a are both sector-shaped, similar to the opening 11 of the tubular electrode 10 . The outer shape of the electromagnetic induction member 17 is slightly smaller than the opening 11 . When the electromagnetic induction member 17 is provided between the opening 11 of the tubular electrode 10 and the turn table 3, the electromagnetic induction member 17 empties the center of the opening 11, and It is arranged so as to substantially cover the outer edge portion. However, since the outer shape of the electromagnetic induction member 17 is slightly smaller than that of the opening 11 , a gap is formed between the cylindrical electrode 10 and the electromagnetic induction member 17 as shown in FIG. 4 .

In addition, since the electromagnetic induction member 17 only needs to vacate the center of the opening part 11 and cover the periphery, the outer shape of the electromagnetic induction member 17 may be made larger than the opening part 11. As shown in FIG. In this case, the electromagnetic induction member 17 is shaped to cover the outer edge of the opening 11 without a gap.

The electromagnetic induction member 17 acts as an auxiliary electrode of the rotary table 3 serving as a cathode. That is, a plasma discharge is generated between the cylindrical electrode 10 and the rotary table 3 serving as a cathode, and plasma is formed in the vicinity of the cathode, that is, directly above the rotary table 3 . Then, the work W is processed by passing the work W under the plasma generated in this way. However, when the work W is insulating and the portion of the rotary table 3 facing the cylindrical electrode 10 is covered with the insulating work W, the plasma discharge becomes unstable, so that the treatment cannot be performed properly. There is a fear that there will be no Therefore, even in this case, the electromagnetic induction member 17 induces the electrons contained in the plasma generated inside the cylindrical electrode 10, and finally the plasma to the workpiece W passing under the hole 17a. to reach The radial width of the hole 17a may be larger than the radial width of the work W so that the plasma reaches the entire work W. As shown in FIG. The circumferential width of the hole 17a may be smaller than the circumferential width of the work W because the entirety of the work W can be plasma-processed by moving in the conveying direction.

When the electromagnetic induction member 17 is provided between the opening 11 of the cylindrical electrode 10 and the turn table 3, the electromagnetic induction member 17 covers an area of 50% to 85% of the opening 11. it should be If it is less than 50%, there is a possibility that the plasma is not sufficiently induced by the electromagnetic induction member 17 . When it exceeds 85%, the area covered by the opening becomes large, and it becomes difficult for plasma to reach the work W on the contrary.

As shown in FIG. 4 , when the outer shape of the electromagnetic induction member 17 is slightly smaller than the opening 11 , the area of the electromagnetic induction member 17 is 50% to 85% of the area of the opening 11 . Do it. When the outer shape of the electromagnetic induction member 17 is larger than the opening 11 , the area of the portion positioned under the opening 11 may be 50% to 85% of the area of the opening 11 .

The electromagnetic induction member 17 may be made of a conductive material. Moreover, it is good also as a material with low electrical resistance. Examples of such materials include aluminum, stainless steel or copper. It may be comprised from the same material as the rotary table 3, and may be comprised from a different material. Also, similarly to the case of the rotary table 3 described above, the particle reduction effect can be obtained even when the electromagnetic induction member 17 is thermally sprayed with aluminum oxide as an insulating material, for example, on the surface of a plate-shaped member made of stainless steel. good. The electromagnetic induction member 17 is placed between the cylindrical electrode 10 and the rotary table 3, and thus is subjected to plasma treatment similar to the work W. It is necessary to replace it when the electrical characteristics are changed by plasma treatment and the force of attracting electrons of plasma weakens. Therefore, depending on the content of the plasma treatment, it may be coated with an etching inhibitor, an antioxidant, or an anti-nitriding agent. Accordingly, it is possible to suppress a change in electrical characteristics and reduce the frequency of replacement.

As shown in FIG. 2 , the electromagnetic induction member 17 is fixed by a supporting member so as to be positioned between the opening 11 of the cylindrical electrode 10 and the rotary table 3 . The support member is composed of an outer support member 18 and an inner support member 19 . The outer supporting member 18 fixes the radially outer side of the electromagnetic induction member 17 from the outside of the rotary table 3 . The inner support member 19 extends from the central portion of the rotary table 3 and fixes the radially inner side of the electromagnetic induction member 17 .

The outer support member 18 is composed of a support rod 18a and a mounting bracket 18b provided at the tip of the support rod 18a. The support rod 18a has an inverted L-shape, and the vertical portion thereof is positioned between the outer periphery of the rotary table 3 and the outer peripheral wall of the chamber 1 , and is erected from the bottom of the chamber 1 . The vertical part of the L-shape of the support bar 18a extends upward to such an extent that the horizontal part of the L-shape is positioned above the upper surface of the rotary table 3, that is, the surface on which the workpiece W is arranged. The horizontal portion of the L-shape is located just above the surface of the turn table 3 , and its tip extends toward the center of the turn table 3 , passes under the flange 14 and the inner shield 13 , and passes through the opening 11 ) is right below the At this tip, as shown in Fig. 4, a mounting bracket 18b is provided.

The mounting bracket 18b may be any that can fix the electromagnetic induction member 17, and is not limited to a specific configuration. 4 : is an example which made the mounting bracket 18b a bolt and a nut. In that case, a bolt hole may be formed in the electromagnetic induction member 17 . The mounting bracket 18b may also be a clip which clamps the electromagnetic induction member 17 by the elastic force of a spring.

The inner support member 19 is composed of a support bar 19a and a mounting bracket 19b provided at the tip of the support bar 19a. The support bar 19a is attached to the tip of the post 3c passing through the opening in the center of the rotary table 3 protruding from the upper surface of the rotary table 3 using a fixing bracket such as a bolt. . The support rod 19a extends radially outward of the rotary table 3 toward the position of the film processing unit 4e. The position at which the tip of the support rod 19a reaches may be in the vicinity of the center of the circumferential width of the cylindrical electrode 10 . The support rod 19a passes under the flange 14 and the inner shield 13 and reaches just below the opening 11 .

The mounting bracket 19b at the distal end of the support rod 19a, similarly to the outer support member 18, can fix the electromagnetic induction member 17, and is not limited to a specific configuration. In addition, the inner side support member 19 and the outer side support member 18 may be made into the mounting bracket 19b of a different structure. For example, the inner support member 19 may be a clip, and the outer support member 18 may be a bolt and a nut. When replacing the electromagnetic induction member 17, for example, the upper surface portion of the chamber 1 is lifted with a jack, and the body is put in from the outside of the chamber 1 to perform the replacement operation. The inner support member 19 on the central side of the chamber 1 is difficult to replace. Therefore, the inner support member 19 may be a clip which can be fixed by inserting the electromagnetic induction member 17 so that the attaching operation may be facilitated. In addition, the outer side support member 18, which is relatively easy to work with, may be a bolt and a nut so that it can be firmly fixed. Of course, as long as the electromagnetic induction member 17 can be fixed only by either the inner support member 19 or the outer support member 18, only either one may be provided.

The plasma processing apparatus further includes a control unit 20 . The control unit 20 is constituted by an arithmetic processing device such as a PLC or a CPU. The control unit 20 includes control related to introduction and exhaust of the sputter gas and process gas into the chamber 1 , control of the DC power supply 7 and the RF power supply 15 , and control of the rotation speed of the rotary table 3 , etc. control of At this time, power sources such as the DC power supply 7 and the RF power supply 15 may be configured separately from the basic configuration of the plasma processing apparatus, and may be used by connecting an existing power supply or a separately prepared power supply.

[movement]

The operation of the plasma processing apparatus of the present embodiment and the operation of the electromagnetic induction member 17 will be described. An unprocessed workpiece W is loaded into the chamber 1 from the load lock chamber. The carried-in work W is held by the holding part 3a of the rotary table 3 . The inside of the chamber 1 is evacuated by the exhaust part 2 to be in a vacuum state. By driving the rotary table 3, the workpiece W is circulated along the conveyance path P, and is repeatedly passed under each of the processing units 4a to 4g. That is, as mentioned later, the film|membrane is formed while the workpiece|work W circulates along the circular conveyance path P, and passes under each processing unit 4a-4g several times.

In the film forming unit 4a, sputtering gas is introduced from the sputtering gas introduction unit 8, and a DC voltage is applied from the DC power supply 7 to the sputtering source. The sputtering gas is turned into plasma by the application of a DC voltage, and ions are generated. When the generated ions collide with the target 6 , the material of the target 6 is ejected. A thin film is formed on the work W by depositing the protruding material on the work W passing under the film forming unit 4a. Film formation is performed in the same manner in the other film forming units 4b, 4c, 4d, 4f, and 4g. However, it is not necessarily necessary to form a film by all film forming units. As an example, here, a Si film is formed on the work W by DC sputtering.

The workpiece W formed into a film in the film-forming units 4a-4d is then conveyed by the rotary table 3 on the conveyance path P, and in the film-processing unit 4e, the cylindrical electrode 10 It passes through the position just below the opening 11, that is, the film processing position. As described above, in this embodiment, an example in which post-oxidation is performed in the film processing unit 4e will be described. In the film processing unit 4e , oxygen gas as a process gas is introduced into the cylindrical electrode 10 from the process gas introduction unit 16 , and a high-frequency voltage is applied from the RF power supply 15 to the cylindrical electrode 10 . Oxygen gas is converted into plasma by application of a high-frequency voltage, and electrons, ions, radicals, and the like are generated. Plasma flows from the opening 11 of the cylindrical electrode 10 as the anode to the rotary table 3 as the cathode. When the ions in the plasma collide with the thin film on the work W passing under the opening 11, the thin film is post-oxidized.

Here, when the work W conveyed by the rotary table 3 is located under the opening part 11, the work W itself functions as a cathode. In the case of using the work W including the insulator, if the insulator is included in the cathode, the impedance of the input side increases. As a result, there is a possibility that the flow of plasma to the cathode side is inhibited and the plasma discharge becomes unstable.

As described above, the matching box 21 is connected to the RF power supply 15 . Even in a state in which the workpiece W including the insulator is positioned under the opening 11, if the impedance of the output side is matched with the impedance of the input side by the matching box 21, the plasma can also flow toward the cathode.

However, as shown in FIG. 3 , there are cases in which the workpieces W are conveyed in a state where the gap between them is very narrow or the size of the gap fluctuates. In such a state, the state in which the insulator is not included and the state in which the cathode is included are drastically changed, and the impedance of the input side is also drastically changed. There is a possibility that the matching process in the matching box 21 cannot keep up with the sharp fluctuations.

In this embodiment, the electromagnetic induction member 17 is arrange|positioned between the opening part 11 of the tubular electrode 10 and the turn table 3 . The electromagnetic induction member 17 acts as an auxiliary electrode of the cathode. That is, the electromagnetic induction member 17 is disposed at an intermediate position between the cylindrical electrode 10 and the rotary table 3 and the work W, and generates plasma generated inside the cylindrical electrode 10 on the rotary table 3 . ) to lead to The induced plasma passes through the hole 17a of the electromagnetic induction member 17 and reaches the workpiece W passing under the opening 11 . In addition, since the electromagnetic induction member 17 covers the outer edge of the opening 11 , the area where the workpiece W faces the cylindrical electrode 10 , that is, the area through which electrons of the workpiece W flows is reduced. Accordingly, the influence of the insulator of the work W on the impedance of the input side is also reduced, contributing to stabilization of the plasma discharge. As a result, even if the workpiece W containing the insulator is conveyed in a state in which the matching process in the matching box 21 cannot catch up, it is possible to perform stable plasma processing without affecting the properties of the workpiece W. can

Here, the electromagnetic induction member 17 is an auxiliary of the rotary table 3 as an electrode to the last, and the cylindrical electrode 10 and the rotary table 3 are each an electrode. If the electromagnetic induction member 17 is a cathode, the rotary table 3 is an insulator, and no electric discharge is generated between the cylindrical electrode 10 and the rotary table 3, that is, the rotary table 3 does not function as an electrode. If not, plasma processing such as post-oxidation becomes weak for the following reasons.

(a) Since plasma is formed between the cylindrical electrode 10 and the electromagnetic induction member 17, the plasma moves away from the rotary table 3 compared to the case where the rotary table 3 functions as an electrode. For this reason, it becomes difficult for the plasma to reach the workpiece|work W.

(b) Since no self-bias is applied to the turn table 3, the force to attract ions to the turn table 3 is weakened.

[exam]

In order to verify the relationship between the area in which the electromagnetic induction member 17 covers the opening 11 of the cylindrical electrode 10 and the plasma discharge, post-oxidation treatment was performed in the film processing unit 4e of the plasma processing apparatus. The film processing unit 4e has the same configuration as the above-described embodiment, but the electromagnetic induction member 17 was not provided in the test. The test conditions are as follows.

· Workpiece: Insulative resin substrate

· Rotational speed of the rotary table: 60 rpm

·Process gas: O ₂ 300 sccm 3 Pa

·High frequency power: 13.56 MHz 300 W

Post-oxidation was performed a plurality of times by changing the number of insulating substrates on which the Si film was formed by a film-forming unit conveyed by the rotary table 3 . And the reflected wave power in each test was measured. By changing the number of insulating substrates, the ratio of the conductive material of the rotary table 3 to the insulator of the work W in the cathode is changed. By verifying the relationship between the ratio of the conductive material and the insulator and the reflected wave power, as a result, it is also possible to verify the relationship between the area in which the electromagnetic induction member 17 covers the opening 11 of the cylindrical electrode 10 and the reflected wave power. At this time, DC sputtering of the Si film was performed simultaneously with the post-oxidation. In addition, since the conditions are the same as a well-known thing, they are abbreviate|omitted.

Fig. 5 shows the test results. In a state of three insulating substrates, the area of the conductive material in the cathode is 43%. At this time, the reflected wave power is 60 W with respect to the traveling wave power of 300 W, and a return loss of about 20% is occurring. On the other hand, when the number of insulating substrates decreases, that is, when the area of the conductive material in the cathode increases, the reflected wave power decreases and the return loss also decreases. In the example where there are 2 insulating substrates and the area of the conductive material is 62%, the reflected wave power is 20 W, and in the example where the insulating substrate is 1 sheet and the area of the conductive material is 81%, the reflected wave power is 10 W. .

That is, when the electromagnetic induction member 17 covers 50% of the area of the opening 11 , the influence on the impedance of the insulator is reduced, and effective plasma processing can be performed. In a state in which there are zero insulating substrates, that is, in a state in which the electromagnetic induction member 17 covers 100% of the opening 11, the reflected wave power becomes 0 W, but naturally the plasma does not reach the work W. In order to ensure the path|route of the plasma to the workpiece|work W, it is good to set the upper limit of the area of the electromagnetic induction member 17 with respect to the opening part 11 to 85%.

[effect]

(1) In the plasma processing apparatus of the present embodiment, an opening 11 is formed at one end, a cylindrical electrode 10 into which a process gas is introduced, and a voltage applied while circulating and conveying the workpiece W The cylindrical electrode 10 includes a rotary table 3 serving as a conveying portion for passing under the opening 11 of the tubular electrode 10 , and an electromagnetic induction member 17 disposed between the opening 11 and the rotary table 3 .

By disposing the electromagnetic induction member 17 between the opening 11 of the tubular electrode 10 and the rotary table 3, the electrons generated in the plasma are transferred to the electromagnetic induction member without affecting the properties of the workpiece W or the conveyance state. (17), it is possible to stabilize the plasma discharge. By stabilizing the plasma discharge, ions, radicals, etc. generated in the plasma reach the workpiece W stably. As a result, it is possible to provide a plasma processing apparatus capable of improving the processing efficiency without affecting the properties or conveying state of the workpiece W and stabilizing the quality of the film formed on the workpiece W.

(2) The electromagnetic induction member 17 is a ring-shaped member having a hole 17a in the center. Since the electromagnetic induction member 17 is positioned between the opening 11 and the rotary table 3, the area in which the workpiece W faces the cylindrical electrode 10, that is, the area of the workpiece W through which electrons flow is reduced. . Therefore, even when the workpiece W contains an insulator, the influence on the impedance of the input side is also reduced, contributing to stabilization of the plasma discharge. Also, the plasma induced by the electromagnetic induction member 17 may reach the work W through the hole 17a.

(3) The electromagnetic induction member 17 may cover an area of 50% to 85% of the opening 11 . If it is less than 50%, there is a possibility that electrons generated in the plasma are not sufficiently induced by the electromagnetic induction member 17 . When it exceeds 85%, the area covered by the opening 11 increases, making it difficult for ions, radicals, etc. generated in the plasma to reach the work W on the contrary. By making the area where the electromagnetic induction member 17 covers the opening 11 equal to 50% to 85% of the opening 11, the electrons generated in the plasma can be sufficiently induced, and ions and radicals generated in the plasma can also be removed from the workpiece ( W) can be reached. For this reason, while stabilizing the discharge, it is possible to perform good processing of the workpiece while ensuring the processing efficiency of the workpiece W.

(4) The rotary table 3 is arranged inside the chamber 1 which is a vacuum container, and holds the workpiece|work W on the surface. The cylindrical electrode 10 is disposed above the work W holding position of the rotary table 3 . The plasma processing apparatus is a support member attached to the chamber 1 and supporting the electromagnetic induction member 17 between the opening 11 of the cylindrical electrode 10 and the rotary table 3 , and an inner support member 19 . and the outer support member 18 may be provided. By using the support member, the electromagnetic induction member 17 can be fixed on the rotating table.

(5) The outer support member 18 is erected from the bottom in the vicinity of the outer periphery of the chamber 1 , and extends just below the cylindrical electrode 10 , and is positioned between the rotary table 3 and the cylindrical electrode 10 . The electromagnetic induction member 17 is supported. By providing in the vicinity of the outer periphery of the chamber 1, when replacing the electromagnetic induction member 17, an operation|work becomes easy.

(6) It is erected in the interior of the chamber 1, and the tip portion further includes a post 3c penetrating the center of the rotary table 3 . The rotary table 3 is rotatably supported by the post 3c via the ball bearing 3d which is a bearing. The inner support member 19 is attached to the post 3c and extends just below the cylindrical electrode 10 to support the electromagnetic induction member 17 between the rotary table 3 and the cylindrical electrode 10 . . By attaching the inner support member 19 to the immovable post 3c that supports the rotary table 3 , the electromagnetic induction member 17 can be fixed on the rotary table 3 .

(7) The electromagnetic induction member 17 may contain an electroconductive member and an etching inhibitor, antioxidant, or nitridation inhibitor coated around the electroconductive member. The electromagnetic induction member 17 arranged under the cylindrical electrode 10 is also plasma-treated similarly to the work W, and when the characteristic changes, replacement becomes necessary. By coating with an etching inhibitor, antioxidant, or nitridation inhibitor in accordance with the plasma treatment mode, the change in properties can be suppressed and the replacement frequency can be reduced.

[Other embodiments]

(1) This invention is not limited to embodiment mentioned above. For example, in the above-described embodiment, the shape of the electromagnetic induction member 17 is a ring shape covering the outer edge of the opening 11 of the cylindrical electrode 10, but it is possible to induce plasma electrons to the workpiece W. If it is, it is not limited to this shape. For example, as shown in FIG. 6 , the electromagnetic induction member 17 may be a rectangular plate-shaped member 170 . The width in the circumferential direction of the plate-shaped member 170 may be smaller than the width in the circumferential direction of the opening 11 . In addition, in accordance with the fan-shaped opening 11, the width in the circumferential direction of the plate-shaped member 170 may be made to expand in diameter from the radial center side to the outside. The plate-shaped member 170 is installed so as to cross the radial center of the opening 11 . A radial direction is a direction orthogonal to the conveyance direction of the workpiece|work W by the rotary table 3 . By installing in this way, the plate-shaped member 170 covers the central portion in the radial direction of the opening 11, and both ends of the central portion are opened. Plasma generated inside the cylindrical electrode 10 is guided to the plate-shaped member 170 , passes through both ends of the opening 11 to reach the work W. Thereby, similarly to the above-described embodiment, stable plasma processing can be performed without affecting the properties of the work W. In addition, the radial width of the plate-shaped member 170 may have a width close to the radial width of the opening 11 so as to uniformly induce plasma.

(2) Further, in the above-described embodiment, the electromagnetic induction member 17 is attached to the chamber 1 using the outer support member 18 and the inner support member 19, but as shown in FIG. , the electromagnetic induction member 17 may be attached to the tip of the cylindrical electrode 10 through the insulating material 22 . The electromagnetic induction member 17 is grounded by being electrically connected to the upper surface portion of the chamber 1 or the inner shield 13 . By connecting via the insulating material 22, the cylindrical electrode 10 and the electromagnetic induction member 17 are not electrically connected, so that the electromagnetic induction member 17 can act as an auxiliary electrode on the cathode side. By attaching to the cylindrical electrode 10, since there is no need to separately prepare a supporting member, the number of parts can be reduced.

(3) In the above-mentioned embodiment, although the aspect of attaching the outer side support member 18 and the inner side support member 19 of the electromagnetic induction member 17 to the bottom part of the chamber 1 was demonstrated, it is not limited to a bottom part. Instead, it may be attached to the upper surface or wall surface of the chamber 1, for example.

(4) The trajectory of the circulation conveyance is not limited to the circumference. By the endless conveyance path, the aspect of being circulated conveyed is widely included. For example, a rectangle or an ellipse may be sufficient, and a crank or a meandering path|route may be included. The endless conveyance path may be constituted by, for example, a conveyor or the like.

(5) A bias voltage may be applied to the rotary table 3 . In addition, a magnet may be disposed under the rotary table 3 . Since electrons are trapped by these, plasma is more likely to be formed on the rotary table 3 .

1: chamber, 2: exhaust part, 3: rotary table, 3a: holding part, 3b: rotating shaft, 3c: post, 3d: ball bearing, 4a, 4b, 4c, 4d, 4f, 4g: processing unit (film forming unit) , 4e: processing unit (membrane processing unit), 5: load lock unit, 6: target, 7: DC power supply, 8: sputter gas inlet, 9: partition wall, 10: cylindrical electrode, 11: opening, 12: external shield, 13 : inner shield, 14: flange, 15: RF power source, 16: process gas inlet, 17: electromagnetic induction member, 17a: hole, 18: outer support member, 19: inner support member, 18a, 19a: support rod, 18b , 19b: mounting bracket, 20: control unit, 21: matching box, 22: insulating material, 170: plate-shaped member (electromagnetic induction member), P: conveying path, W: work.

Claims (9)

In the plasma processing apparatus,
A cylindrical electrode having an opening formed at one end to introduce a process gas therein and generate plasma;
a conveying unit passing under the opening of the tubular electrode to which a voltage is applied while circulating conveying the work;
and an electromagnetic induction member disposed between the opening and the conveying unit to cover a part of the opening;
The cylindrical electrode acts as an anode, and the conveying part acts as a cathode,
The electromagnetic induction member acts as an auxiliary electrode of the cathode, induces electrons contained in the plasma generated inside the cylindrical electrode, and reaches the work passing under the opening, ions or radicals generated in the plasma comprising an electromagnetically inducing member;
and the electromagnetic induction member covers a portion of the opening. According to claim 1,
The plasma processing apparatus according to claim 1, wherein the electromagnetic induction member is a ring-shaped member having a hole in its center. According to claim 1,
The plasma processing apparatus according to claim 1, wherein the electromagnetic induction member is a plate-shaped member traversing a central portion of the opening portion in a direction orthogonal to a conveyance direction of the conveying unit. 4. The method according to any one of claims 1 to 3,
The conveying unit has a rotary table for holding and circulating conveying the work,
The rotary table and the cylindrical electrode are disposed in a vacuum vessel,
The cylindrical electrode is disposed above the holding position of the work of the rotary table,
The plasma processing apparatus of claim 1, further comprising a support member for supporting the electromagnetic induction member between the opening and the rotation table. 5. The method of claim 4,
The support member is installed upright from a bottom portion near an outer edge of the vacuum vessel and extends just below the cylindrical electrode, and an outer support for supporting the electromagnetic induction member between the rotary table and the cylindrical electrode A plasma processing apparatus comprising a member. 6. The method of claim 5,
It is installed standing up in the interior of the vacuum container, the tip portion further comprises a post penetrating the center of the rotary table,
The rotary table is rotatably supported on the post through a bearing,
wherein the support member includes an inner support member attached to the post and extending just below the cylindrical electrode to support the electromagnetic induction member between the rotary table and the cylindrical electrode. . 3. The method of claim 1 or 2,
The plasma processing apparatus according to claim 1, wherein the electromagnetic induction member is connected to the tip of the cylindrical electrode through an insulating material. 4. The method according to any one of claims 1 to 3,
The electromagnetic induction member covers an area of 50% to 85% of the opening. 4. The method according to any one of claims 1 to 3,
The plasma processing apparatus according to claim 1, wherein the electromagnetic induction member includes a conductive member and an etching inhibitor, antioxidant or nitridation inhibitor coated on the conductive member.

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