Film forming device

Abstract

[Problem] To provide a film-forming device in which an anode part provided with a function for generating a magnetic field is positioned between a cathode part and an object being processed, whereby it is possible to reduce adhesion of particles emitted from a cathode to a magnetic-field-generating part and to efficiently form a vapor-deposited film having few droplets, which are by-product fine particles emitted from the cathode. [Solution] A film-forming device that evaporates a cathode material constituting a cathode using a plasma-generating means for generating plasma by performing arc discharge to form a film by vapor deposition on the surface of an object being processed. The plasma-generating means is provided with a cathode part, an anode part disposed a suitable distance from the cathode part, a magnetic-field-generating part, and a protective member. The magnetic-field-generating part is configured from the anode part or is configured integrally or continuously with the anode part and generates a magnetic field using a current produced through arc discharge. The protective member is configured from a portion of the anode part or is configured independently while being electrically connected to the anode part and is positioned outside a region where the plasma flow descends to protect all or part of the magnetic-field-generating part from adhesion of cathode material.

Description

Technical Field

[0001] The present invention relates to a film forming apparatus, and particularly to an apparatus that generates plasma by arc discharge in a vacuum (for example, 0.0001 to 50 Pa) and vapor-deposits a film of a cathode material on the surface of a workpiece.

Background Art

[0002] Generally, it is known that by generating plasma, a thin film is formed on the surface of a solid material (workpiece), or the surface characteristics of the solid material (workpiece) are improved by ion implantation. Films formed using plasma containing metal ions and / or non-metal ions strengthen the wear resistance and corrosion resistance of the solid surface and are useful as protective films and the like. In particular, carbon films using carbon plasma are known to have high utility value as diamond-like carbon films (DLC films) composed of an amorphous mixture of diamond and graphite structures. Also, metal nitride films such as titanium nitride films and titanium aluminum nitride films formed by introducing nitrogen gas into the atmosphere and evaporating metals or alloys such as titanium (Ti) and titanium aluminum (TiAl) can be used in various applications such as protective films for tools and parts and decoration of other members. Such methods are called vacuum arc evaporation, arc ion plating, arc PVD, cathode arc evaporation, and the like. In general vacuum arc evaporation apparatuses, the vacuum vessel itself often functions as the anode, but the present invention relates to a form in which the anode is independent of the vacuum vessel and is disposed inside the vacuum vessel.

[0003] Incidentally, plasma containing metal ions and nonmetal ions is produced by vacuum arc discharge. Vacuum arc discharge occurs between the cathode and anode, and exists on the surface of the cathode. From the high-temperature cathode point, which is the starting point of the vacuum arc discharge, the cathode material evaporates, and this evaporated cathode material forms the vacuum arc plasma. Furthermore, if one or more reactive gases (nitrogen, oxygen, hydrogen, hydrocarbons, fluorine, silicon, etc.) or inert gases (noble gases) are introduced as the atmospheric gas, these gases are also ionized simultaneously. By using such plasma, surface treatment processes such as thin film formation on solid surfaces and ion implantation were performed. Alternatively, a liquid containing the substance to be reacted could be vaporized and introduced into the process vessel.

[0004] As described above, in a vacuum arc discharge that forms a plasma, constituent particles such as electrons and cathode material evaporation particles (atoms (or molecules)) are emitted from the cathode point, and droplets (also called macroparticles) ranging in size from submicrons to several hundred microns (0.01 to 1000 μm) are simultaneously emitted as by-product fine particles. At this time, electrons emitted from the cathode point collide with the cathode material evaporation particles, causing these particles to ionize and generating metal ions and / or nonmetal ions. Cathode material evaporation particles are ionized by collisions with electrons immediately after being emitted from the cathode point (at a very short distance of about a few mm from the cathode surface), but cathode material evaporation particles that are not ionized (excluding those that are later ionized), introduced gas particles (molecules or atoms), and reaction particles (molecules) become neutral particles (hereinafter sometimes simply referred to as neutral particles) and travel in a straight line in the initial emission direction as particles unaffected by magnetic and electric fields. On the other hand, droplets (by-product particles) are released by sudden boiling at the cathode, but since they do not carry an electric charge, they travel in a straight line unaffected by magnetic and electric fields. However, in surface treatment of solid materials, the adhesion of droplets (by-product particles) to the substrate surface has been a problem. That is, when droplets (by-product particles) adhere to the surface of a solid material, the surface becomes uneven, so the uniformity of the thin film is not maintained, and the product may be considered low quality or defective.

[0005] Therefore, in order to avoid the adhesion of droplets (by-product particles), some inventors of the present invention have proposed a plasma generator configured to separate the plasma flow and droplets (by-product particles) by bending the plasma flow emitted from the plasma generation unit (the plasma flow from the vacuum arc plasma generated at the cathode point toward the anode and / or the workpiece; hereinafter sometimes referred to as the plasma flow) with a curved magnetic field, thereby guiding the plasma flow in a direction away from the plasma generation unit, while guiding the by-product particles in a direction opposite to the plasma generation unit (see Patent Document 1). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2002-008893 [Patent Document 2] Japanese Patent Publication No. 2005-216575

[0007] [Non-Patent Document 1] Andre Anders, “Approaches to rid cathodic arc plasmas of macroand nanoparticles: a review”, Surface and Coatings Technology, 120-121(1999)319-330 [Overview of the project] [Problems that the invention aims to solve]

[0008] In the technology disclosed in the aforementioned Patent Document 1, a roughly T-shaped branching structure was used to direct droplets (by-product particles) in a straight line and bend the plasma flow laterally. As a result of this branching, the droplets (by-product particles) were separated from the plasma flow, and only the plasma flow could reach the solid material. However, droplets (by-product particles) emitted from the plasma generation unit sometimes collided with the side walls of the plasma path through which the plasma was traveling, and the droplets (by-product particles) were reflected by these collisions and mixed into the plasma flow. These droplets (by-product particles) mixed into the plasma flow then adhered to the surface of the solid material, hindering the smoothness of the surface.

[0009] Therefore, some of the inventors of the present invention have devised a configuration having a limiting plate inside the plasma path that restricts the movement of droplets (by-product particles) and an oblique wall that reflects the droplets (by-product particles) that have passed through the limiting plate (see Patent Document 2). In this configuration, the direction of movement of droplets (by-product particles) is restricted by a limiting plate provided near the plasma generation section, and the droplets (by-product particles) that have passed through the limiting plate and are moving in the intended direction are further reflected by the oblique wall and collected by a collection section placed at a desired position. With this configuration, it is possible to avoid the mixing of droplets (by-product particles) into the plasma flow.

[0010] However, when bending the plasma flow using a curved magnetic field as described above, a distance of 500 mm or more is required from the plasma generation unit (cathode unit) to the solid material (workpiece), and it was generally set within the range of 500 mm to 1,000 mm. The reason for this is that in order to bend the plasma flow, it is necessary to arrange multiple magnetic field generators while securing space for the plasma flow, resulting in a longer flow path length. There is also a configuration in which the flow path that also serves as the magnetic field generating coil is S-shaped (see Non-Patent Literature 1), but even in this case, the effective flow path length of the plasma flow is still long. However, when the distance from the plasma generation unit (cathode unit) to the solid material (workpiece) is long, the density (flux) of the evaporated material formed by the arc discharge decreases, thus limiting the film deposition rate. Therefore, in order to improve the film deposition rate, it was necessary to adopt a configuration that could shorten the distance between the plasma generation unit (cathode unit) and the solid material (workpiece).

[0011] Furthermore, in a configuration where the plasma flow path is S-shaped to deliver the plasma to the opposing solid material (workpiece) and shorten the plasma flow path length, droplets (by-product particles) separated from the plasma flow are configured to travel in a straight line, unlike the S-shaped curved plasma flow. However, because the magnetic generation coil is curved to create the S-shaped flow path, a gap is created in the curved portion of the magnetic generation coil, and droplets (by-product particles) travel through this gap towards the opposing solid material (workpiece), potentially adhering to the solid material (workpiece). In addition, when the plasma flow path is formed by a magnetic field generator, particles emitted from the cathode may adhere to the magnetic field generator itself, and because the coil-shaped magnetic field generator has a complex shape, removing (cleaning) these deposits becomes extremely cumbersome.

[0012] The present invention has been made in view of the above points, and its object is to provide a film deposition apparatus that reduces the adhesion of by-product fine particles to the surface of the workpiece, reduces the adhesion of particles emitted from the cathode (including those that have reacted with the atmospheric introduction gas) to the magnetic field generating part itself, and can effectively deposit and form a film. [Means for solving the problem]

[0013] Therefore, the first configuration of the present invention is a film deposition apparatus that includes a plasma generating means for generating plasma by performing an arc discharge between a cathode and an anode connected via a power supply in a vacuum, and for evaporating a cathode material constituting the cathode to deposit a film on the surface of an object to be processed, wherein the plasma generating means comprises a cathode portion, an anode portion arranged at an appropriate distance from the cathode portion, a magnetic field generating portion composed of the anode portion, or configured integrally or continuously with the anode portion, which generates a magnetic field by the self-current of the arc discharge itself, and a protective member composed of a part of the anode portion, or configured independently while being electrically connected to the anode portion, or substituted by a part of the magnetic field generating portion, which is positioned between the magnetic field generating portion and the plasma to protect part or all of the magnetic field generating portion from the cathode material.

[0014] According to the above configuration, the magnetic field generating unit generates a magnetic field by utilizing the current from an arc discharge by the anode (anode or a component integrally or continuously configured therewith) that constitutes the plasma generating means, and can generate a magnetic field for inducing a plasma flow at a position very close to the plasma generating means. A protective member is provided outside the plasma flow induced by this magnetic field generating unit, and by placing this protective member between the cathode and the magnetic field generating unit, the magnetic field generating unit can be protected from particles emitted from the cathode (hereinafter sometimes referred to as emitted material). Protection means protecting the magnetic field generating unit from the adhesion of emitted material. In addition to electrons, emitted material also includes neutral particles (evaporative material) and droplets (by-product fine particles) that do not have an electric charge. Some of the neutral particles, which are evaporative material, become ions through collisions with electrons. Charged particles such as electrons and ions are guided by the magnetic field of the magnetic field generating unit towards the workpiece, but neutral particles and droplets are not affected by the magnetic field and travel in a straight line in the direction from which they are emitted radially. Therefore, if droplets adhere due to the selection of the cathode material, the magnetic field generating unit can be protected by adhering these droplets to the protective member along with neutral particles. Of course, ions that could not be controlled by the magnetic field will also adhere, but this explanation will be omitted from now on. Furthermore, if droplets do not adhere (including conditions in which adhesion is difficult; the same applies hereinafter), the magnetic field generating unit can be protected by causing the droplets to collide with the protective member, and the magnetic field generating unit can be protected by adhering neutral particles to it. However, since droplets do not adhere (or adhere difficult), the magnetic field generating unit will not be adversely affected by droplets even if the degree of protection is insufficient. The purpose of deflecting (reflecting) the impacted droplets with the protective member is solely to prevent them from traveling towards the workpiece. That is, by adjusting the reflective surface of the protective member so that the direction of travel after reflection does not go towards the workpiece, the amount of droplets reaching the workpiece can be reduced.Here, droplets that travel from the cathode to the workpiece from the outset may adhere to the surface of the workpiece. However, if this amount of adhesion is accepted, the amount of droplet adhesion will be reduced compared to when no preventive measures are taken. Furthermore, allowing not only high-energy ions but also neutral particles to reach the surface of the workpiece contributes to the effective deposition and formation of a film.

[0015] The second configuration of the present invention is the configuration of the first described above, wherein the magnetic field generating section is formed in a substantially cylindrical shape around the region in which the plasma flow flows, and the protective member is a water-cooling ring member that is arranged at least one end of the substantially cylindrical magnetic field generating section located on the cathode side or the opposite side, and has a surface area of ​​an appropriate size in the radial direction of the magnetic field generating section and has a hollow portion for introducing cooling water into the interior.

[0016] With the above configuration, the magnetic field generator is made roughly cylindrical, and the plasma flow is guided to flow inside it. By placing a ring-shaped protective member (partially cut and not a perfect ring; preferably has a plane with an appropriate width in a direction approximately perpendicular to the direction of plasma flow; a curved surface is also acceptable; this explanation will be omitted below) on either the cathode side or the opposite side of the magnetic field generator, evaporated particles and droplets can be attached to this protective member, or the magnetic field generator can be protected by reflecting droplets while evaporated particles (meaning those that become deposited material including reaction products with the introduced gas; this explanation will be omitted below) are attached. Basically, by placing the protective member on the cathode side, evaporated particles (neutral particles evaporated from the cathode and subsequently ionized particles) and droplets can be attached (or reflected) before reaching the magnetic field generator. Furthermore, by providing a protective member on the opposite edge, the amount of droplets reaching the workpiece can be reduced by causing droplets adhering to (or reflecting) the protective member as they travel toward the workpiece. In this case, the protective member is electrically connected to the anode and functions as part of the anode, and also functions as part of the plasma generation means. Therefore, by introducing cooling water into the hollow interior, the temperature rise of the anode can be reduced. Note that "approximately cylindrical" refers to an electromagnetic coil wired in a coil shape, but the concept also includes configurations in which non-circumferential members are electrically connected, as well as coil shapes formed continuously in the circumferential direction.

[0017] A third configuration of the present invention is that, in the first configuration, the magnetic field generating unit is formed in a substantially cylindrical shape around the region in which the plasma flow flows, and the protective member is composed of a cylindrical member disposed between the region in which the plasma flow flows and the magnetic field generating unit.

[0018] In the above configuration, since a cylindrical protective member is formed inside the substantially cylindrical magnetic field generating section, the magnetic field generating section is protected from cathode material contained in the plasma flow by the protective member. At this time, the protective member is electrically connected to the magnetic field generating section, so that the cylindrical protective member effectively functions as the anode of the plasma generating means.

[0019] A fourth configuration of the present invention is that, in the third configuration, the protective member has a plurality of through holes.

[0020] In the above configuration, when droplets that do not adhere to the protective member are generated, the protective member prevents bounce (reflection), allowing the droplets to pass through the through-hole. By releasing them outside the plasma flow region, the amount of droplets reaching the workpiece is reduced. Furthermore, the areas that are not penetrated will be subject to the adhesion of evaporated particles (including neutral particles, ions, and reaction particles with the introduced gas), thus reducing the amount of adhesion to the magnetic field generating section.

[0021] Furthermore, the fifth configuration of the present invention is such that, in the third configuration, the protective member is formed such that at least its inner surface is not flat.

[0022] In this configuration, instead of allowing droplets to pass through the through-hole as described above, the amount of droplets reflected back towards the workpiece is reduced by diffuse reflection. Specifically, by processing the inner surface of the protective member to be intentionally uneven rather than flat, the bounce angle (reflection angle) of the droplets is changed, reducing the amount of droplets heading towards the workpiece. On the other hand, since the evaporated particles can adhere to the surface without bouncing back, the magnetic field generating part can be protected.

[0023] The sixth configuration of the present invention is to embody the fifth configuration, and the inner surface of the protection member is provided with a number of standing portions formed by partially making incisions at multiple locations of the protection member, bending a part thereof, and standing it up, a number of through holes formed by perforating appropriate locations, a number of concave portions formed by forming appropriate intervals in a concave shape, a number of protrusions formed by forming appropriate intervals in a convex shape, or a shape selected from a number of annular protrusions continuously protruding in the circumferential direction of a substantially cylindrical shape.

[0024] The above configuration shows a specific example when the inner surface of the protection member is configured not to be flat. When the shape is such that a number of standing portions are provided by partially making incisions at multiple locations, bending a part thereof, and standing it up, the droplets can be suppressed from bouncing back in the forward direction by colliding with the portions standing up by bending. Further, when forming a number of through holes formed by perforating appropriate locations, in addition to passing through the through holes, the bouncing-back direction when colliding with the inner peripheral portion of the through hole can be deflected from the direction toward the object to be processed. When forming a number of concave portions formed by forming appropriate intervals in a concave shape, or when forming a number of protrusions formed by forming appropriate intervals in a convex shape, the droplets are made to collide with these concave portions or protrusions to change the bouncing-back direction, thereby reducing the amount of droplets heading toward the object to be processed. These concave portions and protrusions may be provided regularly or irregularly. When forming protrusions, they may be a number of annular protrusions continuously protruding in the circumferential direction of a substantially cylindrical shape. Since the evaporation particles will adhere in any state, it contributes to protecting the magnetic field generating portion. Needless to say, the surface shape and holes of the protection member are structured such that removal (cleaning) of deposits from the protection member is easy and the function does not deteriorate even after cleaning.

[0025] The seventh configuration of the present invention is that, in each of the above configurations, the magnetic field generating portion is a coil-shaped magnetic field generating portion formed by continuously configuring a conductive material in a spiral shape or formed by continuously configuring a hollow conductive material in a spiral shape.

[0026] According to the above configuration, the magnetic field generating unit functions as part of the anode in the plasma generating means, or is electrically connected to a protective member and generates a magnetic field by passing a current in a spiral manner to generate an arc discharge. The magnetic field generated by this coil-shaped magnetic field generating unit can guide the plasma flow in a predetermined direction inside it.

[0027] Furthermore, if the coil-shaped magnetic field generating section is made of a hollow conductive material, it becomes possible to introduce cooling water into the hollow interior, and by introducing cooling water, the temperature rise of the magnetic field generating section, which functions as an anode, can be cooled by the cooling water.

[0028] The eighth configuration of the present invention is that, in any of the first to sixth configurations, the magnetic field generating unit is composed of a plurality of conductive plate-shaped members arranged at appropriate intervals, the plate-shaped members are arranged in a substantially horseshoe shape with a cut portion in part of the ring, one of the edges on both sides of the cut portion of the plate-shaped member is electrically connected to the other edge of an adjacent plate-shaped member, and the current due to arc discharge flows sequentially through the adjacent plate-shaped members in a substantially spiral manner.

[0029] According to the above configuration, the magnetic field generating unit consists of multiple roughly horseshoe-shaped plate members arranged in a ring. By sequentially electrically connecting the cut edges of the roughly horseshoe-shaped plate members, current can be passed through the multiple plate members in the same circumferential direction, and a magnetic field can be generated by passing the current in a manner approximating a spiral. At this time, since the individual plate members are arranged in a ring with respect to the plasma flow formed on the inside, the surface of the plate members becomes the adhesion surface for evaporated particles and can function as an adhesion surface or reflective surface for droplets. In other words, the plate member located on the cathode side functions as a protective member, protecting the other plate members (part of the magnetic field generating unit) that are placed after it. Note that the plate members do not all have to be the same size, and some can have smaller diameters. This is because, as described above, when the plasma flow is bent and moved, by making the plate members near the bend smaller in diameter than the other plate members, the magnetic flux density at the bend can be increased, thereby reducing the loss of transported ions. Furthermore, by providing a protective member, adhesion of evaporated particles and adhesion or collision of droplets to the plate-shaped member is suppressed. However, by causing evaporated particles and droplets that pass through the protective member to adhere to (or reflect) the plate-shaped member, it is possible to reduce the amount of droplets that reach the workpiece.

[0030] The ninth configuration of the present invention is the eighth configuration, wherein the plate-shaped member is arranged so that its substantially horseshoe-shaped central position is sequentially displaced in an angular direction with respect to the direction in which the plasma flow flows, and the central hole of the magnetic field generating section is made to meander.

[0031] In this configuration, the plasma flow meanders according to the shape of the magnetic field generating section due to the meandering of the central hole of the magnetic field generating section. However, the surface of the plate-like member protrudes in the direction from the cathode towards the workpiece, and functions as an adhesion surface for evaporated particles and an adhesion or reflection surface for droplets. If the degree of this meandering is large, one of the plate-like members will be positioned on the straight line through which evaporated particles and droplets reach the workpiece, thereby at least preventing droplets from reaching the workpiece.

[0032] A tenth configuration of the present invention is the ninth configuration in which a hollow annular water-cooling ring member is arranged at any position from the starting end to the ending end of the plate-shaped member in the magnetic field generating unit. In this configuration, when the plate-shaped member functions as the anode of the plasma generating means, the temperature rise of these plate-shaped members can be reduced.

[0033] In addition, it is preferable that the magnetic field generating unit in each of the above inventions generates a magnetic field with a magnetic flux density in the range of 0.01 to 20 mT. By setting the magnetic flux density within an appropriate range, the direction of flow of the plasma flow can be properly guided. [Effects of the Invention]

[0034] According to the present invention, the magnetic field generating unit for inducing plasma flow generates a magnetic field by an electric current that generates an arc discharge generated by the plasma generating means. This shortens the distance the plasma is induced to flow, and by causing droplets to adhere to the protective member or controlling the direction in which they bounce off the surface of the protective member over that short distance, it is possible to suppress droplets from reaching the workpiece. Furthermore, by causing evaporated particles (and the attached droplets) to adhere to the protective member, it is possible to suppress their adhesion to the magnetic field generating unit itself, eliminating the need for cleaning the attached material. In addition, some neutral particles, in addition to high-energy ions, reach the workpiece, thereby enabling efficient film formation. [Brief explanation of the drawing]

[0035] [Figure 1] This is an explanatory diagram showing the overall layout of the film deposition apparatus. [Figure 2] This is an explanatory diagram showing details of the first embodiment. [Figure 3] This is an explanatory diagram showing details of the second embodiment. Note that Figure 3(b) is a modified example. [Figure 4] This is an explanatory diagram showing another variation of the second embodiment. [Figure 5] This is an explanatory diagram showing the details of the magnetic field generating unit in the third embodiment. [Figure 6] This is an explanatory diagram showing a usage example of the third embodiment. [Figure 7] This is an explanatory diagram showing details of the fourth embodiment. [Figure 8] These are scanning electron microscope images of the experimental results and comparative experiments. [Figure 9] This is an explanatory diagram showing a modified example of the embodiment. [Figure 10] This is an explanatory diagram showing other variations of the embodiment. [Figure 11] This is an explanatory diagram illustrating other variations. [Modes for carrying out the invention]

[0036] The embodiments of the present invention will be described below with reference to the drawings. First, the overall structure of the film deposition apparatus will be given a general overview, and then the details will be explained.

[0037] Figure 1 shows a schematic diagram of a film deposition apparatus. The schematic diagram of the film deposition apparatus according to the present invention comprises a plasma generating means 1, a plasma duct 2 which serves as a transport path for evaporated particles produced by the evaporation of the cathode material by the plasma generating means, and a film deposition chamber 3 for performing film deposition. The plasma generating means 1 includes a cathode section 11 and an anode section 12 provided nearby therein, each connected to an external arc power supply 13 via an insulating introduction terminal 4 to enable arc discharge.

[0038] The cathode section 11 is provided with a cathode 11A made of a film-forming material, and this cathode 11A corresponds to the target (raw material for evaporation). Although the cathode 11A is configured to also serve as the target, the film-forming material that serves as the target may be individually arranged on the surface of the cathode 11A. The constituent material of the cathode 11A, which also serves as the target, is not particularly limited as long as it is a conductive solid, and elements of metals, alloys, elements of inorganic materials, inorganic compounds, etc., can be used. These can be used individually or as mixtures of two or more types. For example, as elements of metal, all typical metals and transition metals can be used. Among them are Al, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Ag, In, Sn, Sb, Hf, Pt, Au, Hg, Pb, Nd, Ta, W, Mo, etc. As alloys or intermetallic compounds, there are TiAl, TiCr, TiSi, AlSi, AlCr, NdFe, etc. In addition, inorganic elements include C (graphite), and inorganic compounds (ceramics) include oxides such as TiO2, ZnO, SnO2, ITO (Indium-Tin-Oxide), In2O3, Cd2SnO4, and CuO. Furthermore, carbides and nitrides such as TiN, TiAlC, TiC, CrN, and TiCN can be mentioned. There are also mixtures of two or more of these. Nonmetallic materials can also be mixed within a range that maintains the conductivity of the cathode 11A (semiconductor or semimetallic), such as B, C, Si, P, Ge, As, Se, Sb, Te, Bi, Po, and At. In addition, atmospheric gases include He, Ar, H2, N2, O2, fluoride gas, hydrocarbon gas, chloride gas, sulfide gas, and mixtures thereof, and gases or liquid vapors containing fluorine, hydrogen, carbon, chlorine, sulfur, boron, phosphorus, etc., may also be introduced.

[0039] The anode 12 can be any conductive material that can withstand temperatures of around 200°C, and its material is not limited. It can be a single metal, alloy, a single inorganic element, or an inorganic compound, and the materials exemplified for the cathode can be appropriately selected and used. These can be used individually or as a mixture of two or more. For example, stainless steel, mild steel, steel, copper, copper alloys, aluminum, aluminum alloys, graphite, etc., can be used.

[0040] A trigger electrode 14 is provided near the cathode 11A described above, and is designed to induce a vacuum arc between the cathode 11 and the anode 12. That is, by temporarily bringing the trigger electrode 14 into contact with the surface of the cathode 11A and then separating it, an electric spark is generated between the cathode 11A and the trigger electrode 14. When an electric spark is generated, the electrical resistance between the cathode 11 and the anode 12 decreases, and a vacuum arc is generated between the two electrodes 11 and 12. In addition, an arc stabilizing magnetic field generator 15 is installed around the cathode 11. This arc stabilizing magnetic field generator 15 is used to stabilize the cathode point of the vacuum arc and the plasma generated by the arc discharge. In the figure, the arc stabilizing magnetic field generator 15 is installed outside the chamber, but it may also be installed inside the chamber or behind the cathode. Multiple generators can also be installed. In other words, a magnetic field should be applied to the cathode surface, or / or the front of the cathode, that stabilizes the cathode point and arc discharge and efficiently transports the plasma flow.

[0041] The region that serves as the transport path for evaporated particles is formed inside the anode portion 12, which is formed in a substantially cylindrical shape. As will be described in detail later, a magnetic field generating section 21 using an electromagnet is provided on the outer circumference of the substantially cylindrical anode portion 12, which generates an induced magnetic field that guides the charged particles generated by the evaporation of the film-forming material in a predetermined direction. This induced magnetic field is oriented along the central axis of the substantially cylindrical anode portion 12.

[0042] The induction of charged particles in the transport path region is linear from the cathode section 11 along the central axis of the substantially cylindrical anode section 12, and the charged particles are supplied to the workpiece A inside the film deposition chamber 3 located at the front. Because this transport path is linear, the distance from the cathode section 11 to the workpiece A can be shortened.

[0043] The film deposition chamber 3 has an opening on the side facing the plasma generating means 1, and is equipped with a workpiece holding means 32 inside for holding workpieces A, B, ..., H. By intermittently rotating this workpiece holding means 31, multiple workpieces A to H can be sequentially brought facing the plasma generating means 1 and subjected to film deposition processing.

[0044] In vacuum arc discharges that form plasma flows, droplets are simultaneously emitted from the cathode point along with electrons and evaporated cathode material particles. At this time, the evaporated cathode material particles collide with electrons emitted from the cathode point, causing the material to ionize and generating metal ions and / or nonmetal ions. Evaporated cathode material particles are ionized by collisions with electrons immediately after being emitted from the cathode point. Neutral particles such as evaporated cathode material particles that are not ionized (excluding those that are subsequently ionized), introduced gas particles, and reaction particles are unaffected by magnetic and electric fields and travel in a straight line in the initial emission direction. On the other hand, droplets are emitted by bumping at the cathode, but since they also have no charge, they travel in a straight line unaffected by magnetic and electric fields.

[0045] <First Embodiment> Herein, a first embodiment of the present invention will be described. Figure 2 shows the configuration of the plasma generating means 1 of this embodiment. As shown in this figure, the anode side of the plasma generating means 1 is configured to include a protective member 5 and an electromagnetic coil (magnetic field generating unit) 21 electrically connected to the protective member 5. The electromagnetic coil 21 is connected to the positive electrode side of the arc power supply and enables arc discharge between the cathode unit 11 and the protective member 5.

[0046] The protective member 5 is formed in a generally cylindrical shape from a conductive material, and can be made of non-magnetic materials such as stainless steel, copper, or a copper alloy. An electromagnetic coil 21 is provided so as to be wrapped around the periphery of this generally cylindrical protective member 5. The protective member 5 and the electromagnetic coil 21 are electrically connected by a connecting portion 51 at the end edge away from the cathode portion 11. The end of the electromagnetic coil 21 furthest from the connecting portion 51 is provided to be connected to the positive electrode side of the arc power supply. The protective member 5 and the electromagnetic coil 21, which are made of conductive material, are provided in a non-contact state so that they do not conduct electricity.

[0047] With the above configuration, when an arc discharge occurs, electrons generated from the cathode 11A (indicated by dashed arrows in the figure; the same applies hereafter) move to the protective member 5, which is made of a conductive material, as shown by the dashed arrows. These electrons then move to the electromagnetic coil 21 via the connection part 51, and move sequentially along the coil, eventually moving to the positive electrode side of the arc power supply via the power supply connection part 16. As a result, current flows through the electromagnetic coil, and the electromagnetic coil 21 can generate a magnetic field.

[0048] In this case, the arc discharge occurs between the cathode 11 and the protective member 5, and the arc plasma X is induced by the magnetic field generated by the electromagnetic coil 21 and flows along the central axis of the protective member 5. Therefore, although the anode 12 is formed by the entire protective member 5 and the electromagnetic coil 21, the anode that contributes to the generation of the arc discharge is formed by a localized part of the protective member 5. In this embodiment, the protective member 5 functions as the anode.

[0049] Furthermore, the protective member 5 functions to protect the electromagnetic coil (magnetic field generating unit) 21. Specifically, the protective member 5 is positioned on the inner circumference side of the electromagnetic coil 21, and since the arc plasma X flows inside the protective member 5, the protective member 5 is positioned between the plasma flow and the electromagnetic coil 21. Evaporated particles and droplets contained in the emitted material are also emitted, but the particles that did not ionize (neutral particles) and droplets are emitted linearly without being affected by the magnetic field from the electromagnetic coil stone 21. Therefore, regardless of the plasma flow (transport path of evaporated particles), they are emitted in a direction perpendicular to the central axis of the electromagnetic coil 21 (direction of the arrow in the figure). The protective member 5 protects the electromagnetic coil 21 from the neutral particles and droplets emitted in this way. Naturally, since the electromagnetic coil 21 is located outside the protective member 5, it is possible to prevent evaporated particles other than neutral particles (particles reacting with the introduced gas) and ions that were not strongly affected by the magnetic field from adhering to the electromagnetic coil 21.

[0050] Neutral particles and droplets among the cathode emissions that reach the inner surface of the protective member 5 will adhere to the inner surface of the protective member 5, just as they adhere during film formation. Therefore, except for those emitted along the central axis of the electromagnetic coil 21, i.e., those emitted at an angle can be removed by adhering them to the protective member 5. This prevents adhesion to the magnetic field generating unit itself. In addition, by adhering droplets to the protective member 5, the amount of droplets and other materials reaching the workpiece can be reduced. The method for removing droplets generated during DLC ​​film formation (droplets that do not adhere) will be described later.

[0051] As described above, the entire anode is composed of a protective member 5 and an electromagnetic coil 21. In other words, the local anode functions with the protective member 5, while simultaneously generating a magnetic field by passing current through the electromagnetic coil 21. This configuration significantly shortens the distance from the cathode 11 to the workpiece, thereby reducing the density reduction of evaporated material formed by arc discharge and improving the film deposition rate.

[0052] <Second Embodiment> A second embodiment of the present invention, as shown in Figure 3(a), is configured in which an annular protective member 6 and an end annular member 7 are arranged at both ends of the electromagnetic coil 21 (the cathode side and the opposite end), having a predetermined wall thickness while having an appropriate difference in dimensions between the outer diameter and the inner diameter. As the protective member 6 is annular as described above, it has a surface with a predetermined area in the radial direction of the electromagnetic coil 21 and a surface with a predetermined area in the circumferential direction on the inner diameter side. Moreover, the inside of the annular structure is formed with an inner diameter sufficient to allow the arc plasma X to pass through. The protective member 6 protects the electromagnetic coil 21 by receiving the adhesion of evaporated particles and droplets with the two types of surfaces described above, and also suppresses the arrival of droplets on the workpiece. By forming a large surface area, it contributes to preventing evaporated particles and droplets from adhering to the electromagnetic coil 21.

[0053] In other words, one of the protective members 6 positioned on the cathode side has its surface facing the cathode 11 and its inner circumferential surface positioned on the cathode 11 side of the electromagnetic coil 21. This allows evaporated particles and droplets to adhere to the protective member 6 before they reach the electromagnetic coil 21, thereby suppressing their arrival at the electromagnetic coil 21.

[0054] On the other hand, the terminal annular member 7, located on the opposite side from the cathode, is subject to the adhesion of evaporated particles and droplets that have passed through the electromagnetic coil 21. Since this terminal annular member 7 also has a surface and an inner surface (especially the inner surface) facing the cathode 11, by deliberately allowing the adhesion of droplets, it prevents the passage of droplets emitted in that direction and suppresses their arrival at the workpiece.

[0055] In this configuration, the protective member 6 and the end ring member 7 are made of conductive material, and the connection part 52 between the protective member 6 on the cathode side and the electromagnetic coil 21, and the connection part 51 between the end ring member 7 on the opposite side of the cathode and the electromagnetic coil 21 are both made of conductive material. This allows the end ring member 7, located on the opposite side of the cathode, to function as the anode during arc discharge. In this case, electrons generated from the cathode 11A mainly move to the protective member 6, which is made of conductive material, as shown by the dashed arrows. These electrons then move to the electromagnetic coil 21 via the connection part 52, and sequentially move along the coil, causing current to flow in the electromagnetic coil 21, which in turn generates a magnetic field. Of course, some electrons reach the electromagnetic coil 21, but they flow through the electromagnetic coil 21 and ultimately flow from the end ring member 7 to the positive electrode of the power supply. Furthermore, if the protective member 6 and the end ring member 7 are made of a non-conductive material, or if the connecting parts 51 and 52 are made of a non-conductive material, electrons generated from the cathode 11A will move along the electromagnetic coil 21, mainly starting from the cathode end of the electromagnetic coil 21, and similarly, current will flow through the electromagnetic coil 21. In this case, it is preferable to connect the positive electrode of the power supply (power supply connection part 16) to the position furthest from the cathode 11 of the electromagnetic coil 21.

[0056] Incidentally, in the above configuration, evaporated particles (including reactive particles of the introduced gas) and droplets may pass between the protective member 6 and the end ring member 7 (see arrow Y in the figure). These types of evaporated particles and droplets may adhere to a part of the electromagnetic coil 21. To prevent this, it is conceivable to make the inner diameter of the protective member 6 located on the cathode side smaller.

[0057] Furthermore, when using graphite or the like as the cathode material (when forming a DLC film), droplets do not adhere to the protective member 6, the end ring member 7, and the electromagnetic coil 21, but instead bounce (reflect) after impact. Therefore, the protective member 6 and the end ring member 7 can be provided to control the direction of the droplets so that they do not travel toward the workpiece. In other words, droplets containing graphite material are reflected by the protective member 6 and the end ring member 7, and guided in a direction different from the direction of the workpiece. At this time, droplets that do not collide with the protective member 6 and pass through are reflected by the surface of the electromagnetic coil 21 or pass through the gaps in the electromagnetic coil 21, and as a result are guided toward a direction other than the direction of the workpiece. In this case, the protective member 6 on the cathode side may be omitted. However, since evaporated particles will adhere, it is preferable to provide the protective member 6 on the cathode side to prevent these evaporated particles from adhering to the electromagnetic coil 21.

[0058] In this embodiment, the annular portion 71 of the terminal ring member 7, which functions as the anode, is made hollow, and by introducing cooling water into this hollow interior 71, the anode side can be cooled (it is made a water-cooled ring member). This cooling structure prevents the temperature of the anode side from rising during arc discharge. If the protective member 6 on the cathode side is to function as the anode, a hollow interior 61 may be provided in the protective member 6 to cool it in the same way. Of course, regardless of whether they function as anodes or not, both 6 and 7 may have hollow interiors 61 and 71, and both 6 and 7 may be configured to be water-cooled.

[0059] <Variation> In the second embodiment described above, the following modifications are possible. As shown in Figure 3(b), a substantially cylindrical protective member 5 is provided with an annular protective member 6 attached to one end (or both ends), and a hollow interior 61 is formed in the annular portion, thereby enabling water cooling. In this case as well, the substantially cylindrical protective member 5 functions as an anode, but it can absorb heat due to its connection with the annular protective member 6.

[0060] Naturally, a substantially annular end ring member 7 (see Figure 3(a)) may also be placed on the opposite side to cool the anode side. Furthermore, in order to suppress the temperature rise of the electromagnetic coil 21, the electromagnetic coil 21 may be made of a hollow member and cooling water may be introduced inside it.

[0061] Another variation, as shown in Figure 4, involves a substantially cylindrical protective member 5 with protective members 6 and end ring members 7 integrally attached to both ends. Integral means not only integrally molded but also integrated by physical joining, etc. When configured integrally in this way, the electromagnetic coil 21 can be protected by the substantially cylindrical protective member 5 and the protective member 6 installed on the cathode side. When the end ring member 7 and the electromagnetic coil 21 are joined by a joint 51 made of conductive material, and the protective member 6 and the electromagnetic coil 21 are joined by a joint 52 made of non-conductive material, electrons generated from the cathode 11A move in the same way as in the first practical configuration. That is, they move from the end ring member 7 to the electromagnetic coil 21 and then move along the electromagnetic coil 21, thereby generating current (electron current of vacuum arc discharge). In this case, the area including the electromagnetic coil 21 functions as the anode. At this time, the connection to the positive electrode of the power supply (power supply connection part 16) is made close to the cathode of the electromagnetic coil 21. Conversely, if the connection portion 52 of the protective member 6 is made of a conductive material and the connection portion 51 of the opposite end ring member 7 is made of a non-conductive material, the flow of current (electron current) will be reversed, and the end of the electromagnetic coil 21 furthest from the cathode portion 11 will function as the power supply connection portion 16.

[0062] According to this embodiment, while the anode side is configured to facilitate arc discharge, the temperature rise of the anode (especially the protective member 6) due to the arc discharge can be reduced, thereby contributing to the efficient generation of arc plasma.

[0063] <Third Embodiment> A third embodiment of the present invention involves forming a substantially helical shape using plate-shaped members instead of the electromagnetic coil 21 in the magnetic field generating section. That is, the electromagnetic coil 21 is made of a conductive material in a coil shape (helical shape), but a substantially helical shape is formed by arranging a plurality of conductive plate-shaped members in parallel and connecting them sequentially via conductive material.

[0064] Let me explain in detail. Figure 5 shows the magnetic field generating section of this embodiment. Note that Figure 5(a) is an exploded perspective view, and (b) is a perspective view showing the whole. As shown in these figures, the individual conductive plate-like members 80a to 80e (five are shown in the figure, but the number is arbitrary) that constitute the magnetic field generating section 8 are roughly horseshoe-shaped (can also be described as C-shaped) with a part of the annular section cut off, and two edges 82a to 82e and 83a to 83e are formed on both sides of the cut section 81a to 81e. All of these plate-like members 80a to 80e are the same shape and are arranged in a sequential parallel state to make electrical contact between adjacent plate-like members 80a to 80e. Stainless steel, copper, copper alloy, aluminum, aluminum alloy, graphite, etc. can be used as the conductive plate material.

[0065] Here, the parallel plate-shaped members 80a to 80e sequentially change the position of their cut portions 81a to 81e at a predetermined angle between adjacent members. This angle adjustment also changes the positions of the edges 82a to 82e and 83a to 83e located on both sides of the cut portions 81a to 81e. For example, in the relationship between the first-priority plate-shaped member 80a and the second-priority plate-shaped member 80b, one edge 82b of the second-priority plate-shaped member 80b faces the other edge 83a of the first-priority plate-shaped member 80a. By joining these opposing edges 83a and 82b with the fastening member 9, the adjacent members 80a and 80b can be electrically connected. The fastening member 9 is composed of a cylindrical conductive portion 93 made of a conductive material, in addition to a typical bolt 91 and nut 92. The conductive portion 93 is positioned between two adjacent plate-shaped members 80a and 80b, thereby electrically connecting them while creating an appropriate gap between them.

[0066] In this way, by connecting all the plate-shaped members 80a to 80e with the fastening member 9, a substantially cylindrical magnetic field generating section 8 can be constructed as a whole, as shown in Figure 5(b). A plasma flow can be made to flow along the inside (central hole) of this substantially annular magnetic field generating section 8. At this time, the current flow is in the same direction in the circumferential direction of each plate-shaped member 80a to 80e, and passes through two types of adjacent edges 82a to 82e and 83a to 83e in an opposing state, sequentially moving to the next priority plate-shaped member 80a to 80e, resulting in a substantially helical shape. By flowing the current in such a substantially helical shape, a magnetic field similar to that of an electromagnetic coil can be generated, and a plasma flow can be guided in the direction along the central axis of the magnetic field generating section 8. Reference numeral 51 in the figure indicates a connection part to a protective member, and reference numeral 84 indicates a connection part for connecting to the positive electrode side of the arc power supply.

[0067] When using the magnetic field generating unit 8 with the above configuration, it can be protected using the protective member 5 (see Figure 6(a)) or the annular protective member 6 (see Figure 6(b)), as shown in Figure 6. Note that in Figure 6, the number of plate-shaped members 80a to 80k has been increased to show the shape of the magnetic field generating unit 8, and the dimensional ratio has not been taken into consideration.

[0068] As shown in Figure 6(a), when using the protective member 5, a connection portion 51 for connecting to the protective member 5 is connected to one end of the plate-shaped member 80k, and the other end of the plate-shaped member 80a is provided to be connected to the positive electrode of the arc power supply.

[0069] Furthermore, as shown in Figure 6(b), when using an annular protective member 6 similar to that of the second embodiment, the protective member 6 should be positioned on the cathode side. However, similar members (end annular member) 7 and (intermediate annular member) 7A may also be installed at the end (opposite side from the cathode) and intermediate positions of the magnetic field generating unit 8, respectively. When these types of annular members 6, 7, and 7A are installed, the inside of the annular portion can be made hollow to allow the introduction of cooling water. In this case, the protection of the magnetic field generating unit 8 from evaporated particles and droplets by the protective member 6 is provided by the surface of the annular portion, but it is easily conceivable that evaporated particles and droplets that pass through the protective member 6 will also adhere to the plate-shaped members 80a to 80k. A cooling mechanism may be provided for any of 80a to 80k.

[0070] However, even if evaporated particles and droplets adhere to these plate-like members 80a to 80k, since these plate-like members 80a to 80k are integrated by the fastening member 9 (see Figure 5), they can be easily separated by releasing the fastening member 9, and the process of removing (cleaning) the adhering material from the separated individual plate-like members 80a to 80k can also be easily carried out. For example, the removal can be done mechanically using a lathe or by shot blasting. Chemical removal using chemicals is also easily performed. Furthermore, the cylindrical protective member 5 shown in Figure 6(a) can also be easily cleaned by removing it from the magnetic field generating unit 8. Since each component is made up of small parts, ultrasonic cleaning of these components is also easy.

[0071] <Fourth Embodiment> The fourth embodiment uses the substantially horseshoe-shaped plate members 80a to 80k described above, but the positions of the plate members 80a to 80k are sequentially displaced in the radial direction of the central hole. This state is shown in Figure 7.

[0072] As shown in Figure 7(a), each plate-shaped member 80a to 80k is similarly shaped like a horseshoe, and, as in the third embodiment, adjacent members are electrically connected to each other by fastening members 9. Therefore, the entire structure can conduct current in a roughly spiral manner. Then, each plate-shaped member 80a to 80k is sequentially displaced in the radial direction.

[0073] In terms of displacement, for example, when using 11 plate-like members 80a to 80k as shown in the figure, the plate-like members are arranged so that they rise radially from the first-rank plate-like member 80a to the next-rank plate-like member 80b, and this is repeated sequentially, with the sixth-rank plate-like member 80f located in the middle as the apex, and the plate-like members from the seventh-rank plate-like member 80g to the final-rank plate-like member 80k are arranged to descend sequentially. By changing the height of each plate-like member 80a to 80k in this way, the central hole of the magnetic field generating unit 8 meanders, and as a result, the transport path of the deposited particles can be considered to be meandering. In this case, by making the height of the first-rank plate-like member 80a and the final-rank plate-like member 80k the same, the entry and exit positions of the transport path of the deposited particles will be the same as when all the plate-like members 80a to 80k are aligned in a straight line.

[0074] In this way, by causing the central hole of the magnetic field generating section 8, through which the current flows in a roughly spiral shape, to meander, the resulting magnetic field causes the flow of the arc plasma X (plasma flow) to meander. In contrast, neutral particles and droplets move in a linear fashion, so the neutral particles and droplets emitted from the cathode 11A collide with the surfaces of the individual plate-like members 80a to 80k. If the material is one to which droplets adhere, they will adhere to the surfaces of these plate-like members 80a to 80k. If the material is one to which droplets bounce (reflect), they will bounce off the surface of the plate-like members 80a to 80k and recede, preventing them from advancing toward the workpiece.

[0075] Furthermore, the first-priority plate-shaped member 80a receives the most collisions from neutral particles and droplets, and those that pass through it collide with the second-priority plate-shaped member 80b. As a result, collisions from droplets are concentrated on the plate-shaped members 80a to 80f located in the first half of the entire magnetic field generating unit 8. In particular, depending on the state of individual displacement, if the central hole of the intermediate plate-shaped member 80f does not overlap with the central hole of the first-priority plate-shaped member 80a, then neutral particles and droplets will not reach the plate-shaped members 80g to 80k thereafter. Therefore, in this embodiment, the magnetic field generating unit 8 can be protected by a part of the magnetic field generating unit 8 (the first half 80a to 80f) from the other part (the second half 80g to 80k). This makes it possible to recover the attached neutral particles and droplets by periodically replacing the plate-shaped members 80a to 80f in the first half.

[0076] In the configuration shown in Figure 7(a) above, no protective member made of a different material from the magnetic field generating unit 8 is provided, but a part of the magnetic field generating unit 8 (plate-shaped members 80a to 80f arranged on the cathode side) functions as a protective member (is used as a substitute for a protective member). In this configuration, the first-priority plate-shaped member 80a can function as the anode. In this case, by providing the connection part 84 to the arc power supply on the last-priority plate-shaped member 80k, the magnetic field generating unit 8 can generate a magnetic field by the self-current (electron current) of the arc discharge itself.

[0077] Furthermore, to cool the anode, an annular protective member 6 may be placed on the cathode side, as shown in Figure 7(b). In this case, annular members (end annular member) 7 and (intermediate annular member) 7A of the same configuration may also be provided at intermediate and end positions (opposite the cathode side), and cooling water may be introduced into these annular portions. In particular, since the temperature rise is significant in the parts where the plasma flow refracts, it is preferable to provide them at three locations (see figure) that correspond to these parts.

[0078] According to this embodiment, the magnetic field generating unit 8 can function as a positive electrode while also functioning as a protective member through a portion of it. Furthermore, although the plasma flow will meander due to the magnetic field generated by the magnetic field generating unit 8, the distance required for this meandering is minimal. As a result, the distance from the cathode unit 11 to the workpiece can be shortened. This reduces the decrease in density of the evaporated material formed by the arc discharge and improves the film deposition rate.

[0079] <Example of experiment> Here, an experiment was conducted to confirm the film deposition state when using a magnetic field generator with a horseshoe-shaped plate member as shown in Figure 7(a). The experimental conditions were as follows: Titanium (Ti) was used as the cathode material, and 15 horseshoe-shaped plate members made of oxygen-free copper were used as the anode. The inner diameter was set to 100 mm near the center and gradually increased to 150 mm at both ends, with the plates arranged in a range of 100 mm to 150 mm. The magnetic flux density of the entire magnetic field generator using the horseshoe shape was approximately 6 mT. The arc current was set to 110 A. N2 was used as the atmospheric gas, and the introduction flow rate was set to 30 sccm. The chamber pressure (film deposition pressure) was set to 0.3 Pa, and the film thickness to be deposited was adjusted to approximately 1.8 μm. The distance between the cathode and the workpiece in the apparatus was approximately 350 mm.

[0080] The surface of the TiN film deposited under the above conditions was observed using a scanning electron microscope. The results are shown in Figure 8(a). For comparison, the surface of the film deposited to the same thickness using a cylindrical anode that does not generate a magnetic field was also observed using a scanning electron microscope, and the results are shown in Figure 8(b). As is clear from the comparison of these two figures (scanning electron microscope images), it was found that there is a significant difference in the state of droplet adhesion on the surface of films deposited to the same thickness.

[0081] <Variation> Next, a modified example of the above-described embodiment will be explained. Figure 9 shows a modified example of the protective member 5 in the first embodiment. Figure 9(a) is a vertical cross-sectional view, and (b) is a side view. As shown in this figure, in this modified example, a plurality of protrusions 152 are provided on the inner surface 150B of the cylindrical main body portion 150 of the protective member 105, making the inner surface 150B non-flat. Non-flat means that, compared to the outer surface 150A, the presence of the protrusions 152 clearly creates an uneven surface.

[0082] This protective member 105 is intended for use when using graphite or the like as a cathode material, such as when forming a DLC film, and droplets emitted from the cathode do not adhere to the protective member 105 but bounce off (reflect) them. In other words, when the inner surface 150B is smooth, droplets that collide with the surface are expected to reflect and head towards the workpiece. However, when multiple protrusions 152 are formed on this inner surface 150B, the likelihood of droplets colliding with one of these protrusions 152 becomes very high. As a result, the reflection angle of droplets that collide with a protrusion 152 is greatly changed, thus reducing the proportion that heads towards the workpiece. In particular, when colliding with a protrusion 152, it is common for the droplet to collide with the surface on the cathode side, so it is expected that the droplet will reflect in the backward direction.

[0083] Alternatively, instead of such protrusions 152, the inner surface 150B may be made uneven by forming a concave portion. Furthermore, the protective member 105 can be used as a connection portion 151 to a magnetic field generating portion (electromagnetic coil, etc.) arranged around the outside of the main body portion 150 by forming an overhang (flange portion) at one end of the main body portion 150. In addition, the thickness of the annular portion of this overhang (flange portion) may be increased, and the inside of the annular portion may be made hollow to allow the introduction of cooling water.

[0084] Another variation is the protective member 205 with the configuration shown in Figure 10(a). In this variation, the projection 252 provided on the inner surface 250B of the main body 250 is annular. Even with this configuration, the reflection direction of the droplets impacting the inner surface 250B can be changed. The illustrated example is annular, but it may also be helical. Furthermore, it may be constructed as a concave annular shape instead of a protruding annular shape. The flange portion 251 is the same as in the above-mentioned variation.

[0085] Furthermore, another modified example is the protective member 305 with the configuration shown in Figure 10(b). In this modified example, the main body portion 350 is provided with a plurality of through holes 353. These through holes 353 are formed in an elongated shape along the generatrix direction of the cylindrical main body portion 350, but they may also be short in shape, circular, or other shapes. Here, they are exemplified as elongated through holes. When this type of through hole 353 is formed, droplets that would collide with the inner surface 350B of the protective member body 350 will pass through without collision, and as a result they will not be reflected by the inner surface 350B, thus preventing them from moving in the direction of the workpiece.

[0086] Naturally, it is conceivable that droplets may collide with and reflect off the inner surface 350B where the through-holes 353 are not provided. However, by increasing the proportion of the through-hole area provided by this type of through-hole 353, the probability of such reflection can be reduced. Furthermore, the aforementioned protrusions 152 or the like may be separately formed on this inner surface 350B.

[0087] Furthermore, the flange portion 351 in this modified example can also be used as a connection point for an electromagnetic coil or the like, or it can be configured to allow cooling water to be introduced into the annular portion, similar to the modified example described above.

[0088] <Summary> As described above, in the embodiments and modifications shown, according to these forms, the magnetic field generating units 21 and 8 for inducing plasma flow generate a magnetic field by the current produced by the arc discharge generated by the plasma generating means. Therefore, compared to configuring them individually, the configuration from the cathode unit 11 to the film deposition chamber 3 can be miniaturized, and the positional relationship can be shortened. In this short distance, droplets can be made to adhere to the protective members 5 and 6 and the end ring member 7, or the direction in which they bounce off the surfaces of the protective members 5, 105, 205, and 305 can be controlled, thereby suppressing at least the droplets from reaching the film deposition chamber 3.

[0089] While embodiments and modifications of the present invention are as described above, these embodiments and modifications are merely examples of the present invention and do not imply that the present invention is limited thereto. Therefore, elements in the above embodiments and modifications can be modified, and other elements can be added.

[0090] For example, when using a cylindrical protective member 5 and an annular protective member 6 with an end annular member 7, the configuration may be modified as shown in Figure 11. Note that Figure 11 is shown as a vertical cross-sectional view. As shown in this figure, the inner diameters of the annular protective member 6 and the end annular member 7 may be made smaller than the inner diameter of the cylindrical protective member 5, thereby reducing the proportion of droplets adhering to the inner surface of the cylindrical protective member 5. In such a configuration, the collision of droplets with the cylindrical protective member 5 can be reduced (Figure 11(a)), and droplets that pass through the cylindrical protective member 5 and head towards the workpiece can be further eliminated (Figures 11(a), (b)). Furthermore, the inner surface of these cylindrical protective members 5 may be provided with the protrusions 152, 252 as described in the modified example above. Furthermore, as shown in Figure 11(a), when using an annular protective member 6, if the protective member 6 is not to function as an anode (and power supply connection part 16), it is electrically disconnected from the cylindrical protective member 5 or the electromagnetic coil 21, specifically by separating them or insulating them. In addition, if the protective member 6 is made of a non-conductive material, the cylindrical protective member and the annular protective member 6 may be physically connected.

[0091] These protective components are easily removable from the anode and, compared to a coiled structure, have a simpler overall structure, making it easy to remove deposited material. For example, they can be removed mechanically using a lathe or shot blasting. Chemical removal using chemicals is also easy. Of course, if the material is not to be removed, the shape of the coiled structure shown in Figures 3 and 4 may be bent as shown in Figure 7.

[0092] Furthermore, when depositing an electrical insulating film, an anode screen may be provided between the anode and the plasma. Details of the anode screen configuration are described in detail in Japanese Patent Publication No. 5-247630, so the figures are omitted here, but in this case, the anode screen is configured to have a large number of small-diameter holes. By providing an anode screen in this way, most of the electrical insulating film material deposited during film formation is deposited on the anode screen, and only the material that leaks out through the small-diameter holes of the anode screen is deposited on the anode. At this time, the electrical insulating film material will not be deposited in the areas shaded by the holes other than the small-diameter holes, thus preventing the anode from being covered with the electrical insulating film material. Even when an anode screen is provided, the arc current (electron current of vacuum arc discharge) can pass through the small-diameter holes and flow to the anode, thus ensuring a stable path for the arc current. As this type of anode screen, a perforated metal made of stainless steel can be used, but other materials may also be used. When using a conductive material, if it is to function as part of the anode until the electrical insulating film material is deposited, it will be electrically connected to the anode of the above configuration described above. [Explanation of symbols]

[0093] 1. Plasma generating means 2 Plasma duct 3 Film formation chamber 4. Insulated introduction terminal 5,6,7,105,205,305 Protective components 8. Magnetic field generation unit 9 Fastening member 11 Cathode 11A cathode 12 Anode section 13 Arc power supply 14 Trigger electrodes 15 Arc-stabilized magnetic field generator 16 Power connection section 21 Electromagnetic coil 51, 52 Connection part 61, 71 Inside of the annular portion of the protective member (hollow interior) 80a, 80b, 80c, 80d, 80e, 80f, 80g, 80k Plate-shaped member 81a,81b,81c,81d,81e Cutting section 82a, 82b, 82c, 82d, 82e Ends of plate-shaped members 83a, 83b, 83c, 83d, 83e The other end of the plate-shaped member 84 Connection part 91 volts 92 Nuts 93 Conductive section 150, 250, 350 Cylindrical main body of protective member 150A Protective member, outer surface of the main body 150B, 250B, 350B Inner surface of the main body of the protective member 151, 251, 351 Flange section (connecting section) 152 Protrusion 252 Projection (ring-shaped) 353 Through hole X Arc Plasma

Claims

1. A film deposition apparatus comprising a plasma generating means for generating plasma by performing an arc discharge between a cathode and an anode connected via a power supply in a vacuum, and for evaporating the cathode material constituting the cathode to deposit a film on the surface of an object to be processed, The plasma generating means is Power supply and The cathode part, an anode portion is arranged at an appropriate distance from the cathode portion, A magnetic field generating unit that generates an inductive magnetic field that guides charged particles generated by the evaporation of the cathode material in a predetermined direction, A protective member that protects part or all of the magnetic field generating section from the cathode material. Equipped with, The magnetic field generating unit is composed of the anode unit, or is composed integrally or continuously with the anode unit, and is electrically connected to the positive electrode of the power supply, and generates a magnetic field by the self-current of the arc discharge itself. The protective member is composed of a part of the anode portion, or is independently configured while being electrically connected to the anode portion, or is substituted by a part of the magnetic field generating portion electrically connected to the positive electrode of the power supply, and is positioned between the magnetic field generating portion and the plasma to protect part or all of the magnetic field generating portion from the cathode material. A film deposition apparatus characterized in that the anode is made to function by all or part of the magnetic field generating unit and the protective member.

2. The magnetic field generating section is formed in a substantially cylindrical shape around the region where the plasma flow is occurring. The film deposition apparatus according to claim 1, wherein the protective member is disposed at at least one end of the magnetic field generating portion, which is formed in a substantially cylindrical shape, on the cathode side or the opposite side, and is composed of a water-cooling ring member having a surface area of ​​an appropriate size in the radial direction of the magnetic field generating portion and a hollow portion for introducing cooling water into the interior.

3. The magnetic field generating section is formed in a substantially cylindrical shape around the region where the plasma flow is occurring. The film deposition apparatus according to claim 1, wherein the protective member is composed of a cylindrical member disposed between the region where the plasma flow occurs and the magnetic field generating unit.

4. The film-forming apparatus according to claim 3, wherein the protective member has a plurality of through holes.

5. The film-forming apparatus according to claim 3, wherein the protective member is formed such that at least its inner surface is not flat.

6. The film-forming apparatus according to claim 5, wherein the inner surface of the protective member has a shape selected from among a number of upright portions formed by partially cutting and bending a portion of the protective member at multiple locations, a number of through holes formed by drilling at appropriate locations, a number of concave portions formed at appropriate intervals in a concave shape, a number of protrusions formed at appropriate intervals in a convex shape, or a number of annular protrusions that continuously protrude in the circumferential direction in a substantially cylindrical shape.

7. The film deposition apparatus according to any one of claims 1 to 6, wherein the magnetic field generating unit is a coil-shaped magnetic field generating unit composed of a conductive material continuously arranged in a spiral, or a hollow conductive material continuously arranged in a spiral.

8. The magnetic field generating unit is composed of a plurality of conductive plate-like members arranged at appropriate intervals, the plate-like members are arranged in a substantially horseshoe shape with a cut portion in part of a ring, one of the edges on both sides of the cut portion of the plate-like member is electrically connected to the other edge of an adjacent plate-like member, and the current due to arc discharge is configured to flow sequentially through adjacent plate-like members in a substantially spiral manner, according to any one of claims 1 to 6.

9. The film deposition apparatus according to claim 8, wherein the plate-shaped members are arranged so that their substantially horseshoe-shaped central positions are sequentially displaced in an angular direction with respect to the direction in which the plasma flow flows, and the central hole of the magnetic field generating section is made to meander.

10. The film deposition apparatus according to claim 9, wherein the magnetic field generating unit is configured such that a hollow annular water-cooling ring member is positioned at any location from the starting end to the ending end of the plate-shaped member.

11. The film deposition apparatus according to any one of claims 1 to 6, wherein the magnetic field generating unit generates a magnetic field with a magnetic flux density in the range of 0.01 to 20 mT.

Images