Magnet Configuration for a Plasma Source for Executing Plasma Processing

Abstract

To improve the etching depth and / or etching homogeneity obtained on the substrate, according to the invention the plasma source comprises one or more individual electrodes or one or more magnets which generate a magnetic field in the vicinity of the electrodes, the magnetic field being on the front or rear side.

Description

Technical Field

[0001] The present invention generally relates to plasma sources, and more particularly to plasma sources having a magnetic configuration.

Background Art

[0002] On the one hand, an electric glow discharge formed by passing a current through a gas such as a defined low-pressure argon or another rare gas by applying a sufficiently high voltage between a cathode and an anode can be used for plasma generation. On the other hand, plasma generation of a gas or gas mixture in the form of a low-pressure plasma can be achieved by the interaction of high-energy electrons, which are provided by an electron source and accelerated to an energy defined by a suitable electrode, with the gas. Such an electron source can be, for example, a cathode vacuum arc evaporator consisting of a suitably shielded arc cathode and an arc anode that receives arc electrons. For gas-plasma generation, these arc electrons are extracted using suitable electrodes and accelerated to high energy. The gas-plasma thus generated can be used for various plasma treatments of a substrate. For example, the inert gas ions (e.g., argon ions) thus generated are useful for ion cleaning of the substrate. Compounds excited and, if necessary, decomposed in the plasma, as well as atomized molecules of gases and gas mixtures, can be used for thermochemical treatment of the substrate or even for coating deposition. It is important to adjust local plasma generation in a manner defined with respect to the treatment objective, using suitable electrodes, with respect to the form, configuration, and operating parameters. One objective is to design the electrodes in such a way that they do not protrude into the treatment space in an obstructive manner, that the electrodes can be applied with a high power density, and that they are as easy as possible to maintain. Furthermore, an object of the present invention is to generate a gas-plasma such that a plasma is formed at the electrodes and can be adjusted in time and location by a suitable magnetic field at at least one electrode introduced into the treatment chamber, whereby the local and temporary plasma distribution in the treatment chamber can be adjusted.

Summary of the Invention

Means for Solving the Problem

[0003] The present invention relates to a vacuum chamber for performing plasma processing, comprising a plasma processing area surrounded by a chamber wall of the vacuum chamber and a plasma source. Here, the plasma source includes at least one cathode configured in the vacuum chamber for cathode vacuum arc evaporation using an arc anode connected to the vacuum chamber, and at least one electrode configured in the vacuum chamber. A shield may be configured in front of the cathode, the electrode having a working surface for collecting electrons emitted from the cathode, the working surface being a two-dimensional surface for collecting electrons emitted from the cathode. The two-dimensional surface has a first orthogonal extension and a second orthogonal extension with respect to the surface normal, the first orthogonal extension being perpendicular to the second orthogonal extension, and the length ratio of the first orthogonal extension to the second orthogonal extension being between 0.1 and 1. A magnet for generating a magnetic field acting on the working surface of the electrode is configured in, or on, or in and on the vacuum chamber.

[0004] Generally, the magnet may include a front-side magnet and / or a rear-side magnet. The front-side magnet is configured in the area of the working surface to generate a front-side magnetic field, and the rear-side magnet is configured behind the working surface to generate a rear-side magnetic field. The magnet according to the present invention may be designed as a magnetic circuit, i.e., as a coil or a plurality of magnets. The magnetic circuit surrounds the working surface or is configured in front of the working surface. Particularly preferably, the electrode according to the present invention comprises the entire magnetic system including a front-side magnetic circuit and a rear-side magnetic circuit.

[0005] In one embodiment of the present invention, any number of electrodes and cathodes may be configured in the vacuum chamber. In this case, the magnet may be configured at each electrode or only at a subset of the plurality of electrodes. Here, the rear-side and / or front-side magnets may be configured at the electrodes.

[0006] According to the present invention, at least one magnet for generating a magnetic field is configured on an electrode in a vacuum chamber. Here, a first electrode and a second electrode may exist. Here, the first electrode may be affected by a first front magnetic field, and the second electrode may be affected by a second front magnetic field. In one embodiment of the present invention, it is also conceivable that the first electrode has a first rear magnetic field and the second electrode has a second rear magnetic field. In the case of a plurality of electrodes, a part of the electrodes (or the first electrode) has a rear magnetic field, and another part of the electrodes (or the second electrode) has a front magnetic field. If there are several electrodes, these may preferably be connected to a common power supply or, of course, to different power supplies (current sources). The magnet on the vacuum chamber according to the present invention can comprise a permanent magnet system and / or an electromagnet. If the magnet comprises an electromagnet, the electromagnet can be designed as an electromagnetic coil coupled to the electrode. If there are a plurality of electrodes, any number of electrodes can have an adjustable magnetic field. The adjustable magnetic field according to the present invention can be adjustable, inter alia, by different currents, a specific magnet configuration, and different polarities. If there are several magnets, the polarity of the magnets, especially the polarity of the rear or front magnets, can be reversible. The electrode according to the present invention can in particular be an evaporator containing at least one metal. All of the measures described above can be used, inter alia, to adjust the homogeneity of the plasma and to influence the homogeneity of the plasma. This is because the discharge can be further modified by the magnetic field at one or more electrodes. Here, by operating a plurality of electrodes each having a single power supply and predetermining and adjusting the current value, the homogeneity can be controlled while maintaining stronger plasma excitation. By adjusting the homogeneity of the plasma, thus, the etching rate and the etching homogeneity can also be adjusted, for example, by the magnetic field according to the present invention. In particular, the etching profile can also be affected by controlling the coil and / or by the configuration of the magnet.

[0007] A general industrial cathode vacuum arc evaporator can be used as an electron source. Before the cathode vacuum arc evaporator used as an electron source (hereinafter simply referred to as an arc evaporator), a shield can be provided in such a form that the cathode vacuum arc evaporator is designed to withstand the heat input from the vacuum arc evaporation. The sizing of one area of such a shield should be larger than the entire area of the cathode vacuum arc evaporator with the surface to be evaporated in order to avoid vaporization of the substrate.

[0008] One or more electron collection electrodes can be used in the form of non-cooled electrodes. However, the use of non-cooled electrodes can lead to limitations on the power that can be applied to the electrodes. For this reason, cooled electrodes, such as water-cooled electrodes, are preferably used.

[0009] One or more general (arc) power supplies capable of providing a voltage up to 100 V and a current up to 400 A can be used as the power supply for the electrodes. Here, depending on the appropriate sizing of the working surface and the operating mode, a current density between 0.1 and 5 A / cm 2 and an output density between 0.25 and 500 W / cm 2 can be achieved at the electrodes.

[0010] A total gas pressure in the range of 0.01 Pa to 5 Pa, preferably a gas pressure in the range of 0.1 Pa to 2 Pa, should be maintained in the chamber during plasma processing. Common gases used as pure gases or gas mixtures depending on the processing purpose are argon, hydrogen, nitrogen, or hydrocarbon gases (e.g., C2H2, acetylene).

[0011] The vacuum chamber according to the present invention can comprise a plurality of electrodes and a plurality of cathodes, in particular both cathode vacuum arc evaporators. Here, some cathodes can have a single shield or several shields. Some cathodes with one shield, in particular cathode vacuum arc evaporators, can advantageously be configured using at least one electrode in the vacuum chamber. In particular, the vacuum chamber can also comprise an equal number of electrodes and cathodes (in particular cathode vacuum arc evaporators), or more electrodes than cathodes (in particular cathode vacuum arc evaporators), or more cathodes (in particular cathode vacuum arc evaporators) than electrodes. Here, the electrodes and cathodes can be configured at different locations (walls, ceiling, floor) in the vacuum chamber. The plasma distribution in the vacuum chamber can be adjusted via both the configuration and the number of electrodes and cathodes (in particular cathode vacuum arc evaporators). Furthermore, for example, an improvement in the etching depth and / or etching homogeneity on a substrate can be achieved in an ion etching process. The use of two or more electrodes allows for the use of different currents on the electrodes and the time-selective application of currents, thus enabling improved control of plasma generation.

[0012] The electron current at the electrode can be adjusted by adjusting the electrode voltage. When the electrode voltage is low, the electron current is low and the plasma activity is low.

[0013] The general maximum electron current at one or more electrodes should be selected to be about 120% of the current of the cathode vacuum arc evaporator. For example, if a cathode vacuum arc evaporator is used as an electron source in a vacuum chamber containing argon at an argon pressure of 0.5 Pa and the cathode vacuum arc evaporator is operated at an arc current of 100 A, the total electrode current should be adjusted to about 120 A. This means that the current at one electrode, or in the case where two or more electrodes are used, the sum of the individual currents at the individual electrodes should be adjusted to a maximum of 120 A. An electrode current that is less than or equal to the arc current is preferred.

[0014] When multiple electrodes (two or more electrodes) are configured along the chamber wall in such a way that they are distributed over the height of the vacuum chamber, each electrode can be operated on a separate power source or on a specific group of power sources so that the electrodes can be switched to operate in parallel at maximum current by operating the electrodes at maximum current or by applying different voltages to different electrodes. The general value of the electrode voltage is in the range of 10V to 50V, and the general electrode current is in the range of 10A to 200A.

[0015] Furthermore, the present invention can be used, for example, to deposit a diamond-like carbon (DLC) coating in order to perform a coating process. When a hydrogenated amorphous carbon (a-C:H) type DLC layer is to be deposited, a mixture of an acetylene (C2H2) gas flow and an argon gas flow should be supplied to the chamber.

[0016] Nearly all coating devices designed to perform a vacuum coating process, such as a physical vapor deposition (PVD) arc evaporation process or a PVD sputtering process, including a high-power impulse magnetron sputtering (HiPIMS) process or a plasma enhanced chemical vapor deposition (PA-CVD) process, can be adapted to perform the plasma treatment process according to the present invention.

[0017] In the configuration according to the present invention, the magnet for generating a magnetic field should be configured in the chamber on the electrode. The magnet can be a front magnet that can be manually controlled so that the magnetic field of the magnet can be changed. However, the front magnet can also be a permanent magnet.

[0018] In the configuration according to the invention, the electron acceleration electrode is not spatially linear in the sense of the relationship between the length of the electrode and the cross-section, which is often rectangular or circular or elliptical. Substantially, a two-dimensional electrode is used. This means that the two-dimensional surface has a first orthogonal extension and a second orthogonal extension with respect to the surface normal, and the first orthogonal extension is perpendicular to the second orthogonal extension. The length ratio of the first orthogonal extension to the second orthogonal extension is between 0.1 and 1. The length ratio of the first orthogonal extension to the second orthogonal extension can also be between 0.2 and 1, in particular between 0.4 and 1, and in particular 1. The working surface is in the range of 5 to 2000 cm 2 and in particular in the range of 25 to 320 cm 2 . The two-dimensional surface can be circular, elliptical, but also rectangular, or have other suitable shapes. When the two-dimensional surface is circular, the first orthogonal extension and the second orthogonal extension correspond in particular to the diameter of the two-dimensional surface. When the two-dimensional surface is rectangular, the first orthogonal extension corresponds to the length of the first edge, and the second orthogonal extension corresponds to the length of the second edge of the two-dimensional surface. When the two-dimensional surface is elliptical, the first orthogonal extension and the second orthogonal extension correspond in particular to the distance from the opposite vertices of the two-dimensional surface. The term two-dimensional also refers, among other things, to the fact that the electrons collide with a substantially flat surface. However, the surface itself can have a certain structure due to the manufacturing or use of the surface. This structuring can occur due to erosion of the electrode when used as a coating source or, for example, by cleaning the electrode via blasting or grinding. The electrode can be eroded by erosion in such a way that the electrode no longer has a smooth or constant structure / edge. Such a structured and eroded electrode is also considered to be substantially flat within the concept of the present invention. The ratio between the maximum depth of the structuring of the two-dimensional surface of the electrode and the smaller orthogonal extension (with respect to the first or second orthogonal extension according to the invention) is at most 0.4, in particular at most 0.3, and in particular at most 0.2. Therefore, the maximum depth of the structuring should always be smaller than the smaller orthogonal extension. In this case, the two-dimensional surface of the electrode preferably has an active magnetic field.

[0019] In the simplest case, a circular electrode having a preferably 100 mm electrode diameter is operated. In this case, the electrode can be attached to the wall of the vacuum chamber and can also be configured at least partially in the chamber wall. When the electrode is configured at least partially in the chamber wall, this has the distinct advantage that the electrode does not protrude significantly into the coating chamber. As explained above, if there are several two-dimensional electrodes, the electrodes can be attached to different chamber walls. For example, if two two-dimensional electrodes are installed, the two two-dimensional electrodes are preferably configured on opposite chamber walls. Of course, it is also possible that several two-dimensional electrodes are adjacent and / or several two-dimensional electrodes are configured on the same chamber wall. In this case, the first and second electrodes preferably have a distance of 20 to 400 mm, specifically 100 to 300 mm, particularly 200 mm when they are operated vertically or side by side on the chamber wall.

[0020] The configuration of the two-dimensional electrodes on the chamber wall has the following particular advantages compared to the state of the art with linear electrodes inside the vacuum chamber. The inside of the vacuum chamber, particularly the plasma treatment area in the center of the vacuum chamber, provides a larger free space. This free space thus enables better use of the chamber. For better use of the chamber, the created free space provides a larger space in the chamber for distributing the substrates to be processed, so that the substrates to be processed can be better distributed in the vacuum chamber. In this way, particularly when the substrates to be processed can be more evenly configured in the chamber, uniform plasma treatment of the surface of the substrates can also be enabled. A further advantage of the configuration according to the invention is that simple cooling of these electrodes according to the invention is possible. The two-dimensional surfaces as present in the electrodes according to the invention are of course much easier and more effective to cool than is possible with linear electrodes. Cooling of the electron-receiving surface can be direct (water flow) or indirect. Indirect is the clamping of a suitable electrode material to a cooling body.

[0021] (Hereinafter, also simply referred to as an evaporator) The material of the cathode of an electron source based on a cathode vacuum arc evaporator can preferably be a metal, especially titanium (Ti), zirconium (Zr) or aluminum (Al). Of course, the material of the cathode can also consist of another suitable element, another suitable alloy or (titanium alloy and / or zirconium alloy and / or aluminum and aluminum alloy), or another suitable metal that is advantageous for the adsorption of hydrogen and / or oxygen. Such characteristics of the cathode of the vacuum arc evaporator can also achieve, among other things, better vacuum quality for performing plasma processes. All possible target materials of the cathode vacuum arc evaporator known from the prior art are suitable as electrode materials. In particular, a carbon target made of an alloy such as pure carbon or a copper-carbon alloy can be used as the electrode material. Conductive evaporator materials such as steel, copper, copper alloy, aluminum, aluminum alloy, or aluminum-titanium, chromium, or vanadium are also suitable as electrode materials.

[0022] In one embodiment of the present invention, a plurality of electrodes can be configured in a vacuum chamber. Here, each electrode preferably comprises a working surface according to the present invention. When the first and second electrodes are present in the vacuum chamber, the second front magnet can be configured in front of the second working surface of the second electrode. The second front magnet can also be configured at least partially adjacent to or around the second working surface. Furthermore, the first front magnet can be configured in front of the first working surface and / or the first front magnet can be configured at least partially adjacent to or around the first working surface.

[0023] The polarity of the magnet or magnetic circuit according to the present invention can be adjusted as desired. In this case, the front and rear magnets (or magnetic circuits) can have the same polarity or opposite polarities. In the case of a plurality of electrodes, the first front magnet can have the same polarity as the second front magnet. Furthermore, it is possible to reverse the first polarity of the first front magnet with respect to the second polarity of the second front magnet. The same applies to the rear magnets. In particular, the magnet can have a changeable polarity.

[0024] In practice, the first electrode and the second electrode can be connected to a common power source, or the first electrode can be connected to a first power source and the second electrode can be connected to a second power source. In particular, the plurality of electrodes can comprise a first group of electrodes connected to the first power source and a second group of electrodes connected to the second power source. When the first electrode and the second electrode are connected to a common power source, the changeable polarities of the first front magnet and / or the second front magnet can be adjusted by reversing or regulating the current applied to the first magnet and / or the second magnet, respectively.

[0025] Throughout all the drawings and throughout the description, unless otherwise specified, the same reference signs designate the same elements, features, and structures. The relative sizes and representations of these elements may be out of scale for clarity, illustrative, or convenience reasons.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0027] The drawings include examples containing one or more embodiments. In this regard, the present invention is not limited to the examples described. For example, one or more features of an embodiment may also be realized in another embodiment or even provided in another type of device.

[0028] Before performing a coating process such as physical vapor deposition (PVD) or coating by diamond-like carbon coating, an arc assist glow discharge process (or an ion etching process) can be performed on one or more substrates. In this case, the ion etching process is used to prepare or adjust the surface, i.e., the substrate surface is heated and etched by ion bombardment. This adjustment improves the bonding between the substrate and the coating. Figure 1 shows a conventional ion etching system. This system comprises a vacuum chamber 1 with evaporators 7 (hereinafter, the term evaporator is an abbreviation for the arc cathode of a cathodic vacuum arc evaporator) configured on both sides of the chamber 1. The evaporator 7 is connected to a DC power supply 8 and can be operated with a voltage of 40 V and a current of up to 300 A. A shutter or shield 12 is connected to the wall of the chamber 1 and is rotatably configured such that the shutter 12 can be rotated so that either the corresponding electrode 7 is shielded or not shielded. A linear electrode 13 is connected to the chamber and is equally spaced from the evaporator 7. The linear electrode 13 can be connected to current sources 11, 14 via switches 15, 16, 17 and has an equal voltage along the electrode 3 in the operating state. The current sources 11, 14 are further connected to the wall of the chamber 1 and can optionally be connected to a rotatable substrate holder 10 via switches 15, 16. A gas such as argon can be introduced into the chamber 1 from a gas source 6 through a valve 5 and an inlet 4. When an arc discharge is ignited, electrons are generated by the evaporator 7 and accelerated towards the linear electrode 13. The electrons excite argon gas atoms and thus generate partially ionized argon atoms, which are deposited on the surface of the substrate 9 to prepare the substrate 9 for coating. This system can be adjusted by the DC power supplies 8, 11, 14 and the rotatable substrate holder 10 only. Thus, this system is characterized by limited ionization, limited adjustability of plasma activation by the linear electrode 13, and limited adjustability of homogeneity in the chamber 1.

[0029] The embodiment according to FIG. 2 shows a schematically represented vacuum-tight chamber 100 and an evaporator 110 provided in the chamber 100 and which can be directly configured on the wall of the chamber 100. Further, a power supply 111 having a negative electrode is provided. This negative electrode of the power supply 111 or power source 111 is connected to the evaporator 110. Thus, in this embodiment, the evaporator 110 is the cathode 110. As represented, the evaporator 110 emits arc electrons which are first partially extracted and accelerated by the electrodes according to the invention and thus excite the working gas - argon (Ar) (often also neon (Ne) or any other suitable gas or gas mixture) and as a result generate a plasma. For this purpose, a positive acceleration voltage enabling an electrode current to the electrodes is applied to the electrodes 120. The control of the electrodes can generally be achieved by voltage or current, or the control of the electrodes can be achieved by the energy consisting of the product of voltage and current. The ions of the plasma then hit the surface of the substrate S which is preferably arranged in a manner such that it is placed in the center of the chamber 100 in order to prepare and activate its surface, for example by cleaning or etching, for a subsequent coating process. Further, a shield 115 is configured to be movable in the chamber 100 of FIG. 2 such that the shield 115 can optionally be arranged between the evaporator 110 and the substrate S. Thus, before the ignition of the cathodic vacuum arc evaporation, the shield 115 can be rotated or otherwise moved in front of the evaporator 110 in order to protect the substrate S from contamination by the evaporator 110 during this process. If there is no cathodic vacuum arc evaporation, the shield can be moved to another suitable position.

[0030] According to FIG. 2, a single electrode 120 is provided. The electrode 120 is connected to the positive electrode of the power supply 121 and thus the electrode 120 is the anode 120. By using different currents and / or different time intervals in the current source 121 of the anode 120, the plasma that can be generated in this system can be affected.

[0031] As shown in FIG. 2, the electrons emitted from the evaporator 110 are guided to the position of the electrode / anode 120 along the first and second electron paths 150. Thus, in turn, the plasma that can be generated in the chamber 100 can be accelerated in the same direction. By the suitable positioning of the first electrode 120 at the desired position, better / easier control of the plasma flow in the chamber 100 is possible, resulting in improved control of the ion impact and the etching of the substrate.

[0032] The embodiment according to FIG. 2a shows a schematically represented vacuum-tight chamber 100 having a structure similar to the chamber 100 according to the embodiment of FIG. 2. However, while the two-dimensional surface of the first electrode 120 according to FIG. 2 is circular, the two-dimensional surface for collecting the electrons emitted from the cathode of the first electrode 120a according to FIG. 2a is rectangular. In this case, the two-dimensional surface for collecting the electrons emitted from the evaporator has a first orthogonal extension and a second orthogonal extension with respect to the surface normal, the first orthogonal extension being perpendicular to the second orthogonal extension, and the length ratio of the first orthogonal extension to the second orthogonal extension being between 0.1 and 1. In the case of the circular electrode 120, the first orthogonal extension and the second orthogonal extension correspond in particular to the diameter of the two-dimensional surface. In the case of the rectangular electrode 120a, the first orthogonal extension corresponds to the length of the first edge, and the second orthogonal extension corresponds to the length of the second edge of the two-dimensional surface.

[0033] The embodiment according to FIG. 2b shows a schematically represented vacuum-tight chamber 100 having a structure similar to that of the chamber 100 in the embodiment according to FIG. 2. However, the embodiment according to FIG. 2b includes a switch device 123 coupled between the first electrode 120 and the power supplies 121, 122. The power supply 121 is configured with its positive electrode on the switch S1 of the switch device 123, and the power supply 122 is configured with its negative electrode on the switch S2 of the switch device 123. When the switch S1 is closed and the switch S2 is open, the electrode 120 can be used as the plasma electrode (i.e., also as the anode) according to the present invention. When the switch S1 is open and the switch S2 is closed, the electrode 120 can be used for the (arc) coating process or the sputtering process (i.e., the target).

[0034] The embodiment according to FIG. 2c shows a schematically represented vacuum-tight chamber 100 having a structure similar to that of the chamber 100 in the embodiment according to FIG. 2. However, the embodiment according to FIG. 2c includes a switch device 123 coupled between the first electrode 120 and the power supply 121. The power supply 121 is configured with its positive electrode on the switch S1 of the switch device 123 and its negative electrode on the switch S2 of the switch device 123. Further, the positive electrode of the power supply 121 is connected to ground via a switch S3, and the negative electrode of the power supply 121 is connected to ground via a switch S4. When the switch S1 is closed, the switch S2 is open, the switch S3 is open, and the switch S4 is closed, the electrode 120 can be used as the plasma electrode according to the present invention. When the switch S1 is open, the switch S2 is closed, the switch S3 is closed, and the switch S4 is open, the electrode 120 can be used for the (arc) coating process or the sputtering process.

[0035] The embodiment according to FIG. 3 shows a schematically represented vacuum-tight chamber 100. In this case, the first electrode 120 and the second electrode 130 are connected to the same power supply 121 or the positive pole of the same power source 121. Accordingly, the first electrode 120 and the second electrode 130 are the first anode 120 and the second anode 130. By using different currents and / or different time intervals in the current source 121 of the anodes 120 and 130, the plasma that can be generated in the present system can be affected.

[0036] Since a common power supply is connected to the first electrode 120 and the second electrode 130, in this configuration, an equal voltage can be applied to the first electrode 120 and the second electrode 130. This current can be applied to both of the electrodes 120, 130 simultaneously and for the same duration.

[0037] The embodiment according to FIG. 4 shows a schematically represented vacuum-tight chamber 100. In the embodiment according to FIG. 4, a first power supply 121 is configured for the first electrode 120, and a second power supply 131 is configured for the second electrode 130. In this case, in particular, since the first power supply can supply a first current to the first electrode 120 and the second power supply can supply a second current to the second electrode 130, the plasma that can be generated in the present system can be affected by using different currents and / or different time intervals in the first power supply 121 and the second power supply 131. Here, the first and second currents can be adjusted independently of each other such that the distribution of the plasma can be shaped by the first and second currents. Here, the first power supply 121 can supply a first current to the first electrode 120 during a first time interval, and the second power supply 131 can supply a second current to the second electrode 130 during a second time interval. The first and second time intervals can be separate or overlapping as desired.

[0038] In the embodiments according to FIGS. 2 to 4, in each case there is a single evaporator 110, whereby a plasma arc is generated using at least one of the anodes 120, 130.

[0039] Examples of plasma sources are schematically represented in FIGS. 3, 4 and 9. In order to be able to better control the flow of electrons in the chamber 100 (i.e., the vacuum chamber according to the invention, hereinafter referred to as the chamber), unlike the case of a device with a linear electrode according to FIG. 1, a plurality of electrodes 120, 130, 140 according to the invention are provided, which have a two-dimensional surface for collecting electrons emitted from the cathode and which can be configured in the chamber. A very important advantage of this configuration is the possibility of arranging the electrodes on one or more walls of the chamber, which thereby enables an improvement in the distribution of the substrates to be processed with plasma in the chamber. As a result, the area in the chamber for plasma processing is better utilized, and as a result, the efficiency can be increased. For example, the vacuum-tight chamber 100 is schematically represented in FIG. 3 or FIG. 4. The evaporator 110 is provided in the chamber 100 and can be configured directly in or on the walls of the chamber 110. The evaporator 110 can contain one or more metals, such as titanium and / or any other metal for evaporation. The negative pole of the power source or power supply is connected to the evaporator 110, thus connecting the evaporator 110 in the form of a cathode. For example, when the evaporator 110 is ignited by a trigger unit, arc electrons accelerated by the electrodes according to the invention are emitted and collide with one or more gases, such as argon (Ar), neon (Ne) or one or more other suitable gases placed in the chamber 110, thus generating plasma. The ions of the plasma then impact the surface of one or more substrates (not shown here) provided in the chamber 100, for example, to prepare the surface of the substrate by cleaning or etching for a subsequent coating process. One or more shields 115 are provided movably in the chamber 100 such that the shield 115 can optionally be arranged between the evaporator 110 and the substrate. Thus, the shield 115 can be rotated or otherwise moved in front of the evaporator to protect the substrate from contamination by the evaporator 110 during this process, before the ignition of the vacuum arc evaporation of the cathode. If there is no cathode vacuum arc evaporation, the shield can be moved to another suitable position.

[0040] According to FIGS. 3 and 4, two electrodes, a first electrode 120 and a second electrode 130, are provided in the chamber 100. The first and second electrodes 120, 130 are connected to the positive pole of at least one power source or current source, thereby connecting the first and second electrodes 120, 130 as the first and second anodes. For example, as shown in FIG. 3, a common power source 121 can be connected to the first electrode 120 and the second electrode 130. In this configuration, an equal voltage can be applied to the first electrode 120 and the second electrode 130. This voltage can be applied to both electrodes 120, 130 simultaneously and for the same duration. Alternatively, according to FIG. 4, the first power source 121 can supply current to the first electrode 120 during a first time interval, and the second power source 131 can supply current to the second electrode 130 during a second time interval. The first and second time intervals can be separate or overlapping as desired. In another embodiment, the first electrode 120 can be connected to the first power source 121, and the second electrode 130 can be connected to the second power source 131. Thus, the first power source 121 can supply a first current to the first electrode 120, and the second power source 131 can supply a second current to the second electrode 130. By using different currents and / or different time intervals, the plasma generated in the system can be affected or controlled or even homogenized.

[0041] As shown in FIGS. 3 and 4, the electrons emitted from the evaporator 110 flow to the positions of the first and second electrodes 120, 130. By the individual suitable positioning of the first electrode 120 and the second electrode 130 at the desired positions, better control of the plasma flow in the chamber 100 is possible, resulting in improved control of ion bombardment and etching of the substrate S. FIG. 9 shows an embodiment in which three individual electrodes, a first electrode 120, a second electrode 130, and a third electrode 140 are provided. Accordingly, corresponding first, second, and third electron paths 160 are created that are directed towards the first, second, and third electrodes 120, 130, 140, respectively, in each case. In the schematic diagrams according to FIGS. 3 and 4, the electrodes 120, 130 are configured on the opposite side of the evaporator 110. However, in the schematic diagram according to FIG. 9, the electrodes 120, 130, 140 are configured on different chamber portions. However, it should be understood that any suitable positioning of the first, second, or optionally the third electrode can affect the electron flow in such a way that improved plasma activation and homogeneity in the chamber can be achieved. Accordingly, any number of electrodes in the chamber can direct the electron flow along the desired path. The evaporator 110 according to FIGS. 3, 4, and 9 can be used with an applied current of 100 A, although of course any other suitable current can be used.

[0042] Figure 5 shows a further embodiment of a chamber 200 in which several evaporators are provided. The chamber 200 comprises a first evaporator 210 and a second evaporator 220 that are connected as cathodes, i.e., connected to the negative pole of a first power source 211 and a second power source 221. The first and second evaporators 210, 220 are provided on the wall of the chamber 200. Alternatively, the first or second evaporator 210, 220 may also be configured on a suitable structure of the wall of the chamber 200 or in the chamber 200. A rotatable or otherwise movable shield 230 is provided near the first and second evaporators 210, 220. The shield 230 may have a size sufficient to shield both evaporators 210, 220. Alternatively, the chamber 200 may comprise a first shield and a second shield, each associated with the first evaporator 210 and the second evaporator 220 (not shown here). Further, a first electrode 240 that is connected as an anode, i.e., connected to the positive pole of a first current source 241, is provided in the chamber 200. As represented by the electron path 260, the electrons emitted from the first evaporator 210 and the electrons emitted from the second evaporator 220 flow towards the first electrode 240. It should be understood that any desired number of evaporators may be used with any desired number of individual electrodes so that the system may comprise a suitable number of evaporators and a suitable number of electrodes.

[0043] The embodiment according to FIG. 6 shows a schematically represented vacuum-tight chamber 200 having a structure similar to that of the chamber 200 according to the embodiment of FIG. 5. However, the embodiment according to FIG. 6 differs from FIG. 5 in that a first electrode 240 and a second electrode 250 are present. In this case, the first electrode 240 and the second electrode 250 are connected to the positive pole of the same power source 241 or the same power supply 241. Accordingly, the first electrode 240 and the second electrode 250 are switched as the first anode 240 and the second anode 250.

[0044] Since a common power source is connected to the first electrode 240 and the second electrode 250, in this configuration, an equal current can be applied to the first electrode 240 and the second electrode 250. This current can be applied simultaneously to both electrodes 240, 250 and for the same duration.

[0045] FIG. 6 shows a further embodiment of a plasma source in which several evaporators are provided therein. Chamber 200 comprises a first evaporator 210 and a second evaporator 220 connected as cathodes. The first and second evaporators 210, 220 can be provided in the wall of chamber 200 or otherwise on chamber 200. Alternatively, the first or second evaporator 210, 220 can be configured on a suitable structure of chamber 200 or within chamber 200. A rotatable or otherwise movable shield 230 is provided near the first and second evaporators 210, 220. The shield 230 can have a size sufficient to shield both evaporators 210, 220. Alternatively, chamber 200 can comprise first and second shields associated with the first evaporator 110 and the second evaporator 220, respectively, in each case. Further, a first electrode 240 and a second electrode 250 are provided in chamber 200, both of which are connected as anodes. As represented by electron path 260, electrons emitted from the first evaporator 210 flow towards the first electrode 240, and electrons emitted from the second evaporator 220 flow towards the second electrode 250. It should be understood that any desired number of evaporators can be used with any desired number of individual electrodes. Thus, for example, the system of FIG. 6 can comprise two evaporators and four individual electrodes such that electrons flow from the first evaporator 210 to two individual electrodes and electrons flow from the second evaporator to two other individual electrodes.

[0046] The embodiment according to FIG. 7 shows a schematically represented vacuum-tight chamber 200 having a structure similar to that of the chamber 200 according to the embodiment of FIG. 6. However, the embodiment according to FIG. 7 differs from FIG. 6 in that a first power source 241 is configured in the first electrode 240 and a second power source 251 is configured in the second electrode 250. Here, in particular, since the first power source can supply a first current to the first electrode 240 and the second power source can supply a second current to the second electrode 250, the plasma that can be generated in this system can be affected by using different currents and / or different time intervals in the first power source 241 and the second power source 251. In this case, the first and second currents can be adjusted independently so that the plasma distribution can be shaped by the first and second currents. Here, the first power source 241 can supply a first current to the first electrode 240 during a first time interval, and the second power source 251 can supply a second current to the second electrode 250 during a second time interval. The first and second time intervals can be separate or overlapping as desired.

[0047] In the embodiments according to FIGS. 5 to 7, in each case, two evaporators 210, 220 are present together with at least one anode 240, 250.

[0048] The embodiment according to FIG. 8 can be used in particularly large systems. By configuring the evaporators 311, 321, 331 and the electrodes 340, 350, 360 along the height of the chamber, that is, along the height of the plasma processing area, several plasma sources can be provided in the chamber, and in each case, the plasma source includes at least one evaporator and one or two or more individual electrodes. Here, each electrode can be supplied by its own power source, or alternatively, a switchable power source can be used simultaneously by several electrodes.

[0049] The chamber 300 of FIG. 8 includes a first evaporator 310, a second evaporator 320, and a third evaporator 330 that are connected as a cathode, that is, connected to the negative electrode of the first power supply 311, the second power supply 321, and the third power supply 331. The first, second, and third evaporators 310, 320, 330 are provided on the same wall of the chamber 300. Alternatively, the first, second, and third evaporators 310, 320, 330 can also be configured on a suitable structure of the wall of the chamber 300 or in the chamber 300. Further, the first, second, and third evaporators 310, 320, 330 can be configured on different walls, the first and third evaporators 310, 330 on one wall, and the second evaporator 320 on another wall, respectively. Three rotatable or otherwise movable shields 334, 332, 333 are provided near the first, second, and third evaporators 310, 320, 330 in each case. Alternatively, the chamber 300 can include a shield having a size sufficient to shield all of the evaporators 310, 320, 330. Further, a first electrode 340, a second electrode 350, and a third electrode 360 that are connected as anodes 340, 350, 360, that is, connected to the first power supply 341, the second power supply 351, and the third power supply 361 at the positive electrode in each case, are provided in the chamber 300. As represented by the electron paths, the electrons emitted from the first evaporator 310, the electrons emitted from the second evaporator 320, and the electrons emitted from the third evaporator 330 flow toward the three anodes 340, 350, 360.

[0050] In the schematic view according to FIG. 8, the electrodes 340, 350, 360 are configured on the opposite side of the evaporators 310, 320, 330. However, it should be understood that any suitable positioning of the first, second, and third electrodes is possible in order to affect the electron flow in such a way that improved plasma activation and homogeneity in the chamber can be achieved. Thus, any number of electrodes in the chamber can direct the electron flow along a desired path. The current applied to the evaporators 310, 320, 330 can be 100 A, but of course any other suitable current can be used.

[0051] Thus, in the embodiment according to FIG. 8, three evaporators 310, 320, 330 are present together with three anodes 340, 350, and 360.

[0052] FIG. 8a shows a further embodiment of a chamber 300 having a structure similar to the chamber in FIG. 8, but the power supplies of the first electrode 340, the second electrode 350, and the third electrode 360 are operated with different energies. In particular, through different energies, the homogeneity of the plasma can be improved, and similarly, the distribution of the plasma can be better controlled by appropriately adjusting the energies in the respective power supplies.

[0053] As can be recognized from FIGS. 4 to 8, the substrate S can be biased negatively or positively, whereby the positive bias must be smaller than the positive bias of the electrode since otherwise all electrons would flow to the substrate. Of course, a properly biased substrate is also suitable for additional plasma control. Furthermore, the working gas and the process gas are supplied to the chambers 100, 200 in the operating state. Here, the working gas is preferably argon (Ar) and hydrogen (H2), and the process gas is preferably nitrogen (N2).

[0054] The embodiment according to FIG. 9 shows a schematically represented vacuum-tight chamber 100 having a structure similar to the chamber 100 according to the embodiment of FIG. 2. However, the embodiment according to FIG. 9 differs from FIG. 2 in that the first electrode 120, the second electrode 130, and the third electrode 140 are present, and the first power source 121 is configured on the first electrode 120, the second power source 131 is configured on the second electrode 130, and the third power source 141 is configured on the third electrode 140. In this case, in particular, the first power source 121 can supply the first energy to the first electrode 120, the second power source 131 can supply the second energy to the second electrode 130, and the third power source 141 can supply the third energy to the third electrode 140. Therefore, the plasma that can be generated in the system can be affected by using different energies and / or different time intervals in the first power source 121, the second power source 131, and the third power source 141. In this case, the first, second, and third energies can be adjusted independently of each other such that the distribution of the plasma can be shaped by the first, second, and third energies.

[0055] FIG. 9 shows an embodiment in which three individual electrodes, the first electrode 120, the second electrode 130, and the third electrode 140, are provided in this way. Accordingly, corresponding first, second, and third electron paths 160 are created that are directed towards the first, second, and third electrodes 120, 130, 140, respectively, in each case. In the schematic view according to FIG. 13, the electrodes 120, 130, 140 are configured on the opposite side of the evaporator 110. However, it should be understood that any suitable positioning of the first, second, or optionally the third electrode can affect the flow of electrons in such a way that improved plasma activation and homogeneity in the chamber can be achieved. Therefore, any number of electrodes in the chamber can direct the electron flow along a desired path.

[0056] The embodiment according to FIG. 9a shows a schematically represented vacuum-tight chamber 100 having a structure similar to that of the chamber 100 according to the embodiment of FIG. 9. However, in the embodiment according to FIG. 9a, the electrodes 120, 130, 140 are not only formed on the chamber wall of the chamber 100. The first electrode 120 is formed on the chamber wall, the second electrode 130 is formed on the chamber ceiling, and the third electrode 140 is formed on the chamber floor. The configuration of the electrodes in the chamber can be adjusted as desired, especially for controlling the plasma distribution.

[0057] Although various exemplary configurations have been illustrated and described within the concept of the present application, other embodiments with any number of evaporators and any number of electrodes will, of course, fall within the scope of protection of the invention claimed herein. Further, the vacuum chamber according to the present invention can be used for an ion-etching process and can be equipped with a plurality of individual electrodes, whereby different currents can be supplied to different electrodes. To operate plasma activation and etching as desired, the same or different currents can be applied to different electrodes and even at different times.

[0058] The electron paths 150, 160, 260, of course, pass near the shields 115, 230, 332, 333, 334 and do not pass through those shields, so the electron paths 150, 160, 260 included in the figure are only schematically represented.

[0059] In FIGS. 2 to 9a, magnets for generating a magnetic field (not shown here) are configured in a vacuum chamber, particularly in the vicinity of the electrodes, or, in the case of a plurality of electrodes, in the vicinity of at least one of the plurality of electrodes. This magnet is particularly preferably configured on the working surface of the electrode. Generally, the magnet may comprise a front magnet and / or a rear magnet. The front magnet is configured in the area of the working surface to generate a front magnetic field, and the rear magnet is configured behind the working surface to generate a rear magnetic field. When there are a plurality of electrodes, the front and / or rear magnets may also be configured on the electrodes or on a subset of the plurality of electrodes. The substrate S can be biased either negatively or positively, and the positive bias should be less than the positive bias of the electrode since otherwise all electrons would flow to the substrate. In the operating state, argon (Ar) and hydrogen (H2) can preferably be supplied as the working gas, and nitrogen (N2) can preferably be supplied as the process gas.

[0060] Next, referring to FIGS. 10 to 12, embodiments are shown in which a magnetic field can be applied to individual electrodes of a vacuum chamber. The electron path can be controlled in a magnetic field that correspondingly affects charged particles in the plasma. More precisely, the diffusion of charged particles is impeded by the magnetic field. As a result, the loss of electrons and ions is reduced and the electron density increases. Generally, to create a magnetic field in the chamber, an electromagnet in the form of a coil is positioned around the chamber from one end to the opposite end. Other conventional systems use a permanent magnet configured under the substrate and moved to generate a magnetic field. However, none of these configurations allow the electron flow to be controlled in such a way that the homogeneity can be adjusted and improved. In the embodiments described herein, the magnetic field is applied to each individual electrode. FIG. 10 shows an embodiment in which the electrode 300 is configured adjacent to or within the electromagnet 302. For example, the electromagnet 302 can be a coil wound around the electrode 30, i.e., configured in the area of the working surface of the electrode. In this case, the magnetic field at the electrode 30 is on the front side. No rear magnetic field is generated.

[0061] Figures 11 to 12 show an embodiment using a rear magnet 320 and a front magnet 310. In Figure 11, the electrode 30 includes an electromagnetic coil 302 provided near or around the electrode 30 (i.e., configured within and / or at least partially adjacent to the area of the working surface). The electromagnetic coil 301 is arranged near the electrode 30 behind the working surface to generate a rear magnetic field as a rear magnet. The electromagnetic coil may or may not include a ferrite core depending on the desired magnetic field strength. As shown in the figure, the two coils 301, 302 are configured such that their coils have the same polarity. In Figure 12, the magnetic field between the electromagnetic coil 301 and the electromagnetic coil 302 has opposite polarities. This change in the polarity of the (rear and front) magnetic field can be achieved by changing the direction of the current passing through the coil 301. Therefore, the magnetic field can be adjusted on a single coil. The diagram in Figure 19 shows an example of the magnetic field strength measured perpendicular to the surface (circular electrode, radius 5 cm, zero point corresponding to the center of the electrode, x-axis radius in cm starting from the center of the electrode) with a coil current of 3 A (y-axis, in mT). The middle curve shows the magnetic field strength of Figure 10 where no rear magnetic field is generated. The upper curve shows the magnetic field strength according to Figure 11 where the magnetic field is generated by coils with equal polarities, and the lower curve shows the magnetic field strength according to Figure 12 where the magnetic field is generated by coils with opposite polarities. In the case of the upper curve, the upper curve is within the negative range from about ±3.2, and therefore the magnetic field has the reverse direction from this radius, so there is a tunnel field. However, in the case of the lower curve, the magnetic field emerging from the working surface has only one direction.

[0062] FIG. 13 shows another embodiment of the present invention. The system shown in FIG. 13 is a vacuum chamber for performing plasma processing using a magnetic field configuration for two electrodes. An evaporator 450 is provided in the chamber and can be directly (at least partially) embedded in the chamber wall or connected to the chamber wall. The negative electrode of a 100 A power source can be connected to the evaporator, connecting the evaporator as a cathode thereto. Thus, when the evaporator is ignited, electrons are emitted, and the electrons collide with argon (Ar) gas introduced into the chamber, thereby generating plasma in that way. Ions in the plasma then impact the surfaces of one or more substrates (not shown) configured in the chamber to be cleaned and / or etched. One or more shields are movably disposed in the chamber in such a form that a shield can be optionally disposed between the evaporator and the substrate. Thus, before the ignition of the cathode vacuum arc evaporator, the shield can be rotated or otherwise moved in front of the evaporator 450 to protect the substrate from contamination. When there is no arc generated by the cathode vacuum arc evaporator, the shield can be moved to an unshielded position. In the chamber according to the present invention, at least one single electrode should be provided in the chamber. However, in FIG. 13, a first electrode 460 and a second electrode 470 are provided, which are connected to the positive electrode of a power supply (also a current source), for example, 80 A, and thus connect the electrodes 460, 470 as anodes. Thus, electrons flow from the evaporator 450 in the direction of the positions of the electrodes 460, 470. This accelerates the generated plasma in the same direction. A first rear magnet 480 and a second rear magnet 490 are configured behind the working surfaces of the electrodes 460, 470 to generate a rear magnetic field. The rear magnetic field can be applied to the electrodes by an electromagnet by configuring an electromagnetic coil behind the working surfaces of the electrodes 460, 470. When using electrodes with a magnetic field, the substrate current increases with substantially the same ion-etching performance, especially doubling, and as a result, the etching of the substrate (substrates) can be improved.

[0063] Although only a single evaporator 450 is shown in FIG. 13, any number of evaporators and also electrodes can be used in the system (as already shown in the description of FIGS. 5 to 8a). For example, larger systems and / or larger chambers may require two or more evaporators to generate a greater number of electrons.

[0064] FIG. 14 shows an embodiment of a chamber 400 having a structure similar to the embodiment according to FIG. 17. In contrast to FIG. 15, the first electrode and the second electrode in FIG. 14 are connected to different power supplies (power supply U1 and power supply U2). As a result, the polarities of the two coils can be controlled and changed independently of each other, which, of course, leads to an improvement in etching homogeneity.

[0065] Here, in the vacuum chamber 400 of FIG. 14, in each case the front magnet (or magnetic circuit) is formed by the first electrode 460 and the second electrode 470. Further, the first rear magnet 480 is formed on the first electrode 460, and the second rear magnet 490 is formed on the second electrode 470. As described above, the rear magnets 480 and 490 are connected to different power supplies (power supply 1 and power supply 2). The front magnet is formed in the vacuum chamber 400 (i.e., under vacuum), while the rear magnets 480 and 490 are formed outside the vacuum chamber 400 (i.e., under atmospheric pressure). It should be understood that the magnet may comprise a permanent magnet. As described above, the vacuum chamber according to the present invention should comprise a magnet configured to generate a magnetic field in or outside the (vacuum) chamber, adjacent to or around the (two-dimensional) working surface of the electrode. In this case, the magnet may comprise a front magnet and / or a rear magnet. Here, in FIG. 15, the front magnet 302 is formed in the area of the working surface 461 to generate a front magnetic field, and the rear magnet 301 is formed behind the working surface 461 to generate a rear magnetic field. Of course, the front magnet may be at least partially formed adjacent to the working surface. Both the front magnet and the rear magnet may be designed as electromagnets, in particular as coils. By using an electromagnet, temporal control of the magnetic field (rear or front, in particular the magnetic field obtained when using both rear and front) becomes possible. Here, the magnetic field can be pulsed, and the intensity of the magnetic field can be adjusted in a substantially the same field direction, and the field direction can also be reversed. By changing the direction of the current in the coil, the polarity of the magnetic field can be adjusted. Particularly preferably, when using the vacuum chamber according to the present invention, a program in which the current in the coil changes therein can be predetermined. In this case, for example, a current of 3 A can be used for the first time interval, and a current of 3 A with the opposite current direction can be used for the second time interval. The first time interval and the second time interval can be the same, but of course, they can also be different. The currents can also be of different intensities. In summary, the magnetic field generated by the coil can be controlled by time, direction, and current.

[0066] The system according to the present invention may also comprise a plurality of front and / or rear magnets, i.e., a front and / or rear magnetic circuit configured in a ring shape. For example, as shown in FIG. 15, the front magnet 302 may be annular or a plurality of front magnets 302 may be configured in a ring shape as a magnetic circuit. For example, the plurality may comprise 20 magnets configured in a specific pattern, with each magnet spaced apart from the others. To generate a front magnetic field, a second plurality of permanent magnets may be configured radially within the first plurality of magnets. The plurality may have a polarity opposite to that of the second plurality. The rear magnet 301 may also be designed as a plurality of magnets configured behind the working surface 461 of the electrode in a pre-determinable structure.

[0067] The annular front magnet 302 according to FIG. 15 has a diameter larger than the circular working surface 461 of the electrode 460. In one embodiment of the present invention, the diameter of the front magnet may be 1.1 to 2 times larger than the diameter of the electrode.

[0068] In principle, the magnetization of the magnet should be generally parallel to the surface normal of the working surface 461. For this purpose, the front magnet 302 may be configured in front of, adjacent to, and around the working surface 461. It is also possible for the magnetic circuit to consist of two magnets, with one pole configured in front of the working surface and one pole configured adjacent to (above or below) the working surface. In particular, the front magnet may also be configured to be movable so that the front magnet can change its position relative to the working surface.

[0069] In summary, the configuration of the magnet(s) is made such that any magnetic field structure (shape and intensity) can be generated at the working surface of the two-dimensional electrode. In this regard, for example, it is possible for the magnetic field strength in the outer area of the working surface to be greater than that in the inner area of the working surface, but the reverse is also possible.

[0070] In general, the magnet according to the invention can be designed at least partially as a permanent magnet, whereby all common magnetic materials such as hard ferrite, alnico (AlNiCo), neodymium iron boron (NdFeB), samarium cobalt (SmCo) etc. can be used as volume material or as plastic bonded magnets. The magnet can be manufactured from a compact or the magnet can be segmented. Preferably, the common magnetic field strength used in the vacuum chamber according to the invention has a magnetic field strength of the vertical component of the magnetic field on the electrode according to the invention between 0.1 and 100 mT, preferably between 1 and 50 mT, in particular between 2 and 20 mT.

[0071] In any of the described embodiments, a substrate holder can be configured in the chamber. The substrate holder preferably comprises a plurality of high-speed steel substrates configured at different heights in the vertical direction. The substrate holder is configured rotatably in the chamber such that the substrate holder plate can be rotated about the central axis of the substrate holder. Furthermore, each vertical configuration of the substrate is rotatable about the individual axis of the substrate. The first electrode and, if present, the second electrode are configured, for example, with a diameter of 100 mm at a pre-determinable vertical position in the chamber. In order to observe the influence on the individual electrodes and the magnetic field during the experiment, measurements can be made at three different heights on the electrodes, namely 210 mm corresponding to the lower end of the second electrode B, 340 mm corresponding to 30 mm above the lower end of the first electrode, and 470 mm corresponding to 60 mm above the upper end of the first electrode A. The etched substrate is a steel body (100Cr6) which was rotated twice in the vacuum chamber.

[0072] Next, in FIG. 17, a chamber similar to the chamber described above is shown, and an additional front magnetic field is applied to the electrodes. The magnetic field of the first electrode 460(A) and the magnetic field of the second electrode 470(B) have opposite polarities. The magnetic field can be used to adjust plasma generation in the vicinity of the first and second electrodes 460, 470, and the adjustment can be achieved by changing the direction of the current applied to each coil. When a current of 80 A is applied to the electrodes, an electrode current of 40 A is applied to the first electrode 460(A), and a current of 40 A is applied to the second electrode 470(B). As can be seen, when the polarities of the magnetic fields applied to the electrodes 460, 470 are directed in opposite directions, the current in the first electrode 460(A) and the current in the second electrode 470(B) remain close to 40 A. However, when the applied magnetic fields have the same polarity, the current in the first electrode reaches approximately 80 A, while the current in the second electrode is close to 0 A. This is because, in this case, the electron current in the second electrode is almost completely shielded.

[0073] The diagram of FIG. 18 and the table of FIG. 20 show the measurements taken at a predetermined height on the device according to 17. The resulting diagram is shown in FIG. 18. The x-axis represents the vertical position above the lower edge (210 mm) of the lower circular electrode B, or, in other words, a pre-determinable height measured in mm, and the y-axis represents the etching depth in nm. It can be seen from the diagram that the substrate provided at a higher vertical position on the substrate holder is etched less strongly than the substrate arranged at a lower position on the substrate holder. The upper line in the diagram shows the embodiment of FIG. 17, and the lower line shows a known system with a linear electrode. According to FIG. 17, in which two single electrodes are operated in parallel, a significantly higher etching rate can be observed due to the faster flow of the substrate in the chamber. However, the homogeneity is not improved, as can be seen from the decrease in the etching depth with the decrease in height. FIG. 19, on the other hand, shows an embodiment in which the homogeneity is improved compared to the state of the art (lower line) by varying the polarity of the magnet over time. The x-axis represents the vertical position above the lower edge (210 mm) of the lower circular electrode B, or, in other words, a pre-determinable height measured in mm, and the y-axis represents the etching depth in nm.

[0074] The first row of the table in Figure 20, labeled "Standard (Stand.)", shows measurements made on a known system with a conventional linear electrode. 80 A was applied to the linear electrode, and the substrate current was measured at 1.9 A. The etching depth for the lower measurement (lower (bot), 210 mm) is 250 nm. The depth at the intermediate measurement (intermediate (mid), 340 mm) is 210 nm, which is 84% of the lower etching depth, and the depth at the upper measurement point (upper (top), 470 mm) is 110 nm, which is 48% of the lower etching depth. The described design with two single electrodes, with only the back magnetic field applied to the electrodes, shows improved etching with an increased substrate current of 3.4 A, but the same problem regarding homogeneity remains. A current of 40 A is applied to each electrode. The etching depth for the lower measurement (lower, 210 mm) is 420 nm. The etching depth at the intermediate measurement (intermediate, 340 mm) is 350 nm (83%), and the depth at the upper measurement (upper, 470 mm) is 180 nm (43%). The next two rows show the results obtained when a magnetic field is applied to the electrodes. When a magnetic field of the same polarity is applied, the current in the first electrode is 75 A and the current in the second electrode is 5 A. The substrate current is at a height of 4.5 A, and the etching depth at the upper measurement (470 mm) is 760 nm. The intermediate measurement (340 mm) is 620 nm (86%), and the lower measurement (340 mm) is 300 nm (39%). When the polarity is changed by reversing the direction of the current applied to the coil, the opposite effect on the etching depth can be observed. The current applied to the first electrode is 49 A and the current applied to the second electrode is 31 A. The substrate current was measured at 4 A. The maximum measured depth in this configuration is found at 640 nm in the lower measurement (210 mm). The intermediate measurement (340 mm) gives 490 nm (76%), and the upper measurement (470 mm) is 240 nm (38%).

[0075] It is desirable to achieve homogeneity in the chamber such that the etching rate is substantially constant over the entire height of the substrate holder. Since the etching profile shows opposite tendencies from top to bottom at the same and opposite polarities of the magnetic field, homogeneity can be achieved by superimposing the etching profiles over a specified time interval. The selected time can be short, such as 1 - 10 rotations of the substrate holder, or longer if necessary. In an example of the configuration according to FIG. 17, 2 / 3 of the process time (e.g., 40 minutes) is used by applying a front magnetic field of the same polarity (as shown by the third row of results in FIG. 20 and the upper curve in FIG. 19), and 1 / 3 of the process time (20 minutes) is used by applying a front magnetic field of the opposite polarity (as shown in the fourth row of results in FIG. 20), and it has been found that good homogeneity can be achieved.

[0076] Although various exemplary configurations have been illustrated and described within the concept of this application, other embodiments with any number of evaporators and any number of electrodes will, of course, fall within the scope of protection of the invention claimed herein. Further, the ion etching system according to the present invention can be equipped with a plurality of individual electrodes, whereby different currents can be supplied to different electrodes. To operate plasma activation and etching as desired, the same or different currents can be applied to different electrodes, and further at different times.

[0077] Although a significant number of embodiments have already been described within the concept of this application, it goes without saying that further variants are possible. For example, the described embodiments can be suitably combined, supplemented, or replaced by equivalent features having the same effect. Accordingly, such other solutions also fall within the scope of protection of the claimed invention.

Claims

1. A vacuum chamber for performing plasma processing, comprising a plasma processing area surrounded by a chamber wall and a plasma source, wherein the plasma source is at least one cathode (110, 210, 220, 310, 320, 330, 450) configured in the vacuum chamber (100, 200, 300, 400) for cathode vacuum arc evaporation using an arc anode connected to the vacuum chamber (100, 200, 300, 400), a shield (115, 230, 332, 333, 334) that can be configured in front of the cathode, at least one electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) configured in the vacuum chamber (100, 200, 300, 400) to increase the homogeneity of the plasma in the vacuum chamber, the electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) comprising a working surface (461) for collecting electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450), and the working surface (461) is a two-dimensional surface for collecting the electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450), the two-dimensional surface having a first orthogonal extension and a second orthogonal extension with respect to the surface normal, the first orthogonal extension being perpendicular to the second orthogonal extension, and the length ratio of the first orthogonal extension to the second orthogonal extension being between 0.1 and 1, at least one magnet (301, 302, 480, 490) for generating a magnetic field acting on the working surface (461) of the electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) is configured inside, or outside, or both inside and outside the vacuum chamber (100, 200, 300, 400), and the polarity of the magnet is varied over time. A vacuum chamber characterized by this.

2. The magnet (301, 302, 480, 490) includes a front magnet (302) or a rear magnet (301, 480, 490), the front magnet (302) is configured in the area of the working surface (461) to generate a front magnetic field, and the rear magnet (301, 480, 490) is configured behind the working surface (461) to generate a rear magnetic field. The vacuum chamber according to claim 1.

3. The front magnet (302) is configured in front of the working surface (461), or the front magnet (302) is configured at least partially adjacent to or around the working surface (461), or the front magnet (302) or the rear magnet (301, 480, 490) is configured in the vacuum chamber (100, 200, 300, 400), or the rear magnet (301, 480, 490) is configured outside the vacuum chamber (100, 200, 300, 400). The vacuum chamber according to claim 2.

4. The front magnet (302) or the rear magnet (301, 480, 490) includes a permanent magnet or an electromagnetic magnet, or the front magnet (302) or the rear magnet (301, 480, 490) is designed as an electromagnetic coil (480, 490) coupled to the electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470). The vacuum chamber according to claim 2 or 3.

5. A first electrode having a first working surface for collecting the electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450), and a second electrode having a second working surface for collecting the electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450) or a plurality of cathodes (110, 210, 220, 310, 320, 330, 450). The vacuum chamber according to any one of claims 1 to 4.

6. A vacuum chamber according to any one of claims 2 to 4, comprising a plurality of electrodes (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470), wherein the front magnet (302) configured in front of the working surface (461) and the rear magnet (301, 480, 490) configured behind the working surface (461) are configured on at least one of the electrodes (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470).

7. The front magnet (302) and the rear magnet (301, 480, 490) are electromagnets, and the vacuum chamber (100, 200, 300, 400) further comprises a current source connected to the rear magnet (301, 480, 490) and the front magnet (302), and the current source is designed such that the flow of current to the rear magnet (301, 480, 490) and the front magnet (302) can be adjusted so that the polarities of the rear magnet and the front magnet can be reversed. A vacuum chamber according to any one of claims 2 to 4 and 6.

8. The plurality of electrodes (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) are connected to a common power source, or the plurality of electrodes (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) include a first group of electrodes (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) connected to a first power source and a second group of electrodes (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) connected to a second power source. The vacuum chamber according to claim 6.

9. A first front magnet for generating a front magnetic field is configured in the area of the first working surface, and a second rear magnet for generating a second rear magnetic field is configured behind the second working surface. The vacuum chamber according to claim 5.

10. A first front magnet for generating a front magnetic field is configured in front of the first working surface, and a second rear magnet for generating a second rear magnetic field is configured behind the second working surface, the vacuum chamber according to claim 5.

11. A first front magnet for generating a front magnetic field is configured adjacent to the first working surface, and a second rear magnet for generating a second rear magnetic field is configured behind the second working surface, the vacuum chamber according to claim 5.

12. A first front magnet for generating a front magnetic field is configured around the first working surface, and a second rear magnet for generating a second rear magnetic field is configured behind the second working surface, the vacuum chamber according to claim 5.

13. The magnetic field strength of the vertical component on the electrodes (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) is between 0.1 mT and 100 mT, the vacuum chamber according to any one of claims 1 to 12.

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