Patent Publication Number: US-2023154734-A1

Title: Magnet system, sputtering device and housing cover

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to German Patent Application No. 10 2021 129 523.8, filed on Nov. 12, 2021, the contents of which are fully incorporated herein by reference. 
     TECHNICAL FIELD 
     Various embodiments relate to a magnet system, a sputtering device, and a housing cover. 
     BACKGROUND 
     In general, workpieces or substrates may be processed, e.g., machined, coated, heated, etched, and/or structurally modified. For example, one process for coating a substrate is cathode sputtering (referred to as sputtering), which is of the physical vapor deposition (PVD) type. By means of sputtering (i.e., by means of a sputtering process), for example, one layer or plurality of layers may be deposited on a substrate. For this purpose, a plasma-forming gas may be ionized by means of a cathode, and a material to be deposited (target material) may be sputtered by means of the plasma formed in the process. The atomized target material may then be brought to a substrate on which it may be deposited and form a layer. 
     Modifications of cathode sputtering are sputtering by means of a magnetron, so-called magnetron sputtering, or so-called reactive magnetron sputtering. In this process, the formation of the plasma may be supported by means of a magnetic field. The magnetic field may be generated by a magnet system and penetrate the cathode (then also referred to as magnetron cathode) so that a toroidal plasma channel, a so-called racetrack, may be formed on the surface of the target material (target surface) in which plasma may form. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the exemplary principles of the disclosure. In the following description, various exemplary aspects of the disclosure are described with reference to the following drawings, in which: 
         FIGS.  1 - 3 A  each show a magnet system according to various embodiments in different views; 
         FIG.  3 B  shows a magnet system of the sputtering device; 
         FIG.  4    shows a sputtering device according to various embodiments, and 
         FIGS.  5 - 6    each show a magnet system according to various embodiments in different views; 
         FIG.  7    shows a sputtering device according to various embodiments; 
         FIGS.  8  and  9    each show a housing cover according to different embodiments in different views; 
         FIG.  10    shows a signal transmission chain of the housing cover according to various embodiments in a similar schematic perspective view; 
         FIG.  11    shows a schematic perspective view of the generator side part of the kinetic chain of the housing cover according to various embodiments; and 
         FIG.  12    shows a schematic perspective view of a gear wheel on the drive side of the gear stage according to various embodiments. 
     
    
    
     DESCRIPTION 
     The following detailed description refers to the accompanying drawings that show, by way of illustration, exemplary details and features. 
     With respect to magnetic fields and sputtering, the spatial distribution of the plasma or the associated atomization rate depends very sensitively on the spatial distribution of the magnetic field. Therefore, the magnet system is of particular importance with respect to various process properties, such as process stability, reproducibility, target utilization and homogeneity. Against this background, there is a fundamental need to improve the magnet system, for example to simplify it and/or to reduce disturbing influences. 
     One aspect of various embodiments may be illustratively seen in that an adjustable magnetic field is provided. By adjusting the magnetic field, atomization of the target material may be influenced, for example in such a way that atomization and/or coating may be as uniform as possible. 
     In this respect, it was illustratively recognized that the components used for this purpose for communication (e.g. signal transmission or drive control) as well as power supply (e.g. power generation or power transmission) increase the design complexity of the magnet system, which complicates its maintenance and reduces its reliability. 
     According to various embodiments, a coherent assembly is provided in the form of a housing cover, which comprises a gear stage, a generator and a rotary coupling (e.g., a rotor through-coupling or a rotary union), and optionally a communication interface. This achieves that the components for power supply and optionally for signal transmission are provided as a structural unit, which may be exchanged as a whole. 
     The gear stage and the generator are used for internal power generation, while the communication interface is used for signal transmission to the adjustment device (e.g. having a motor control). In addition to safe functional performance during operation, the housing cover may be removed or replaced as a complete assembly during maintenance without having to influence or change the remaining components of the solenoid system. 
     In the following detailed description, reference is made to the accompanying drawings which form part thereof and in which are shown, for illustrative purposes, specific embodiments in which the invention may be practiced. In this regard, directional terminology such as “top”, “bottom”, “front”, “rear”, “forward”, “rearward”, etc. is used with reference to the orientation of the figure(s) described. Because components of embodiments may be positioned in a number of different orientations, the directional terminology is for illustrative purposes and is not limiting in any way. It is understood that other embodiments may be used and structural or logical changes may be made without departing from the scope of protection. It is understood that the features of the various exemplary embodiments described herein may be combined, unless otherwise specifically indicated. Therefore, the following detailed description is not to be construed in a limiting sense, and the scope of protection is defined by the appended claims. 
     In the context of this description, the terms “connected”, “attached” as well as “coupled” are used to describe both a direct and an indirect connection (e.g. ohmic and/or electrically conductive, e.g. an electrically conductive connection), a direct or indirect connection as well as a direct or indirect coupling. In the figures, identical or similar elements are given identical reference signs where appropriate. 
     According to various embodiments, the term “coupled” or “coupling” may be understood in the sense of a (e.g. mechanical, hydrostatic, thermal and/or electrical), e.g. direct or indirect, connection and/or interaction. For example, a plurality of elements may be coupled together along an interaction chain along which the interaction may be exchanged, e.g., a fluid (then also referred to as fluidically coupled). For example, two coupled elements may exchange an interaction with each other, e.g., a mechanical, hydrostatic, thermal, and/or electrical interaction. A coupling of a plurality of vacuum components (e.g., valves, pumps, chambers, etc.) to each other may have them fluidically coupled to each other. According to various embodiments, “coupled” may be understood in the sense of a mechanical (e.g., bodily or physical) coupling, e.g., by means of direct physical contact. A coupling may be configured to transmit a mechanical interaction (e.g., force, torque, etc.). 
     As used herein, the term “bearing device” means a device (for example, comprising an assembly) configured for bearing (e.g., guided positioning and/or holding) one or more than one component. The bearing device may comprise, for example per component (which is supported by means thereof), one or more than one bearing for supporting (e.g. guided positioning and/or holding) the component. Each bearing of the bearing device may be configured to provide the component with one or more than one degree of freedom (for example, one or more than one translational degree of freedom and/or one or more than one rotational degree of freedom) according to which the component may be moved. Examples of a bearing have: Radial bearing, thrust bearing, radial-axial bearing, linear bearing (also referred to as linear guide). 
     The term “sputtering” refers to the atomization of a material (also referred to as coating material or target material), which is provided as a so-called target, by means of a plasma. The atomized components of the target material are thus separated from each other and may be deposited elsewhere, for example to form a layer. Sputtering may be performed by means of a so-called sputtering device, which may have a magnet system (in which case the sputtering device is also referred to as a magnetron). For sputtering, the magnetron may be placed in a vacuum processing chamber so that sputtering may be performed in a vacuum. To this end, the environmental conditions (the process conditions) within the vacuum processing chamber (e.g., pressure, temperature, gas composition, etc.) may be adjusted or controlled during sputtering. For example, the vacuum processing chamber may be or may be configured to be air-tight, dust-tight, and/or vacuum-tight, such that a gas atmosphere having a predefined composition or pressure (e.g., according to a set point) may be provided within the vacuum processing chamber. For example, an ion-forming gas (process gas) or a gas mixture (e.g., of a process gas and a reactive gas) may be or are provided within the vacuum processing chamber. In a reactive magnetron sputtering process, for example, the atomized material may react with a reactive gas (e.g., comprising oxygen, nitrogen, and/or carbon) and the resulting reaction product (e.g., a dielectric) may be deposited. 
     Sputtering may be performed by means of a so-called tubular magnetron, in which a tubular target (also referred to as a tube target or tubular cathode) containing the target material rotates axially around the magnet system. By adjusting the magnet system or by changing the magnetic field generated with it, the sputtering of the target material and thus the spatial distribution with which the target is ablated may be influenced. 
     The tubular cathode and magnet system may be supported by means of a bearing device (also referred to as a target bearing device) that rotatably supports the tubular cathode relative to the magnet system, for example. The bearing device may have, for example, one or more than one end block, each end block of the bearing device holding an end portion of the tubular cathode and magnet system, respectively. The bearing device (e.g., its one or more than one end block) may further provide a supply of electrical power, rotary motion, and/or cooling fluid to the tubular cathode. 
     According to various embodiments, an end block (then also referred to as a drive end block) of the sputtering device may include a drive train for transmitting rotary motion to the tubular cathode, which may be coupled to a drive, for example. Alternatively or additionally, an end block (also referred to as a media end block) of the sputtering device may be configured to supply and discharge cooling fluid (e.g., a water-based mixture) that may be passed through the cathode. 
     However, exactly one end block (also referred to as a compact end block) may be used, which has the drive train and fluid line and thus provides the functions of a drive end block and a media end block together. For example, the side of the tube target opposite the compact end block may be freely cantilevered (i.e., freely suspended), which is referred to as a cantilever configuration, or supported by means of a bearing block. 
     The magnet system may be multipolar, i.e., have multiple magnetic poles. Of the plurality of magnetic poles, a first magnetic pole (also referred to as an outer pole) may extend along a self-contained path (also referred to as a circulatory path) and a second magnetic pole may be disposed within the area enclosed by the circulatory path (also referred to as an inner pole). The circulatory path may be oval-shaped, for example. Each magnetic pole may have a plurality of pole bodies, e.g., magnets (then also referred to as a row of magnets or a magnet row), lined up in series, each pole body being magnetized or having magnetization. For example, each magnetic pole may have at least 10 (e.g., at least 100) pole bodies, e.g., magnets, per meter. For example, two or more rows of magnets disposed between the end pieces of the magnet system may provide substantially the center region of the magnet system (illustratively one row the inner pole, one row of magnets on each side of the inner pole the outer pole). Generally, the outer pole and the inner pole may be spaced apart from each other and/or may differ from each other in their direction of magnetization and/or in their number of magnets. 
     As used herein, the term “pole body” means a body having or formed from a magnetic material (also referred to as magnet material). For example, the pole body may be adjacent to or part of a magnetic pole. The magnetic material may be, for example, ferromagnetic or ferrimagnetic. The magnet material may comprise or be formed from hard-magnetic magnet material and/or soft-magnetic magnet material. The magnet material may have a magnetic polarization, such as a magnetization, such that a magnetic dipole is provided. 
     For example, the hard-magnetic magnet material may have a coercivity greater than about 500 kiloamperes per meter (kA/m), e.g., greater than about 1000 kA/m. For example, the hard-magnetic magnet material may comprise or be formed from neodymium-iron-boron (Nd 2 Fe 14 B) or samarium-cobalt (SmCo 5  and Sm 2 Co 17 ). More generally, the hard-magnetic magnet material (e.g., the or each permanent magnet) may comprise or be formed from a rare earth magnet material (such as neodymium-iron-boron (NdFeB) or samarium-cobalt (SmCo)), a ferrite magnet material (e.g., a hard ferrite magnet material), a bismanol magnet material, and/or an aluminum-nickel-cobalt magnet material. 
     For example, the soft-magnetic magnet material may have a coercivity of less than about 500 kA/m, e.g., of less than about 100 kA/m, e.g., of less than about 10 kA/m, e.g., of less than about 1 kA/m. The soft-magnetic magnet material may comprise or be formed from, for example, an alloy of iron, nickel, and/or cobalt, steel, a powder material, and/or a soft ferrite (e.g., comprising nickel tin and/or manganese tin). 
     For example, the magnet material or magnetic (e.g., soft-magnetic and/or hard-magnetic) material may have a magnetic permeability of about 10 or more, e.g., about 100 or more, e.g., about 10 3  or more, e.g., about 10 4  or more, e.g., about 10 5  or more. 
     The magnet system, e.g. its so-called magnet bar, may optionally comprise several segments (also referred to as magnet system segment or as magnet system group) arranged one behind the other and/or spatially separated from each other (e.g. multipolar), of which two segments (also referred to as reversing segments or end pieces) are arranged at the end faces (illustratively at the magnet system end) of the magnet system and of which one or more than one optional segment (also referred to as middle piece) is arranged between the end pieces. Reference is made herein by way of example to a magnet system having a plurality of magnet system groups, wherein what is described with respect thereto may also apply to an unsegmented magnet system, or what is described with respect to one magnet system group may apply by analogy to a plurality of magnet system groups, and vice versa. 
     The term “non-magnetic” may be understood to mean substantially magnetically neutral, e.g., also slightly paramagnetic or diamagnetic. For example, the term “non-magnetic” may be understood as having a magnetic permeability of substantially 1, i.e. in a range of about 0.9 to about 1.1. Examples of a non-magnetic material include: Graphite, aluminum, platinum, copper, aluminum, non-magnetic stainless steel, a ceramic (e.g., an oxide). 
       FIG.  1    illustrates a magnet system  100  according to various embodiments in a schematic detailed view, e.g., looking at that direction  101  (also referred to as reference direction  101 ) along which the magnet system  100  is elongated. For example, the magnet system may have a length (extent along the reference direction  101 ) of more than about 0.5 m (meters) and/or less than about 6 m, e.g., in a range from 2 m about to about 5 m and/or more than 3 m. 
     The magnet system  100  may include a plurality of magnets  104  and a carrier  160  configured to support the magnets  104  of the magnet system  100 . The support structure  160  may include at least one (i.e., one or more than one) carriers  102 ,  202  (also referred to as magnet carriers or magnet holders), a first carrier  102  (also referred to as a first magnet carrier/holder or system carrier) of which is configured to support one or more than one magnet system group  150  of the magnet system  100  (e.g., magnets  104  thereof). 
     For example, the magnet system  100  may include one or more than one magnet system group  150  per system support  102 , e.g., multiple magnet system groups  150  per system support  102 . For example, the magnet system  100  may include two magnet system groups  150  (e.g., per system support  102 ) or more, e.g., three magnet system groups  150  or more. Each magnet system group  150  may have a plurality (e.g., three or more) of magnets  104  and may optionally be configured to be adjustable. At least two magnets  104  per magnet system group  150  may differ from each other in their magnetization direction. 
     Each adjustably configured magnet system group  150  may include an adjustment device  150   s  that is, for example, (e.g., partially) disposed between and/or couples the system support  102  and the magnet(s)  104  of the magnet system group  150 . The adjustment device  150   s  may be configured to change a spatial distribution of the magnetic field  120  generated by the magnet system group  150 , for example, by changing a spatial distribution (e.g., position and/or orientation) of the magnet(s)  104  of the magnet system group  150 . For example, the adjustment device  150   s  may be a component of the support structure  160  and configured to change the spatial position and/or orientation of at least one magnet of the magnet system  100 . 
     Exemplary components of the adjustment device  150   s  include: a bearing device  116  (also referred to as a group bearing device) and/or an actuator  106 . The adjustment device  150   s  (e.g., its group bearing device  116  and/or actuator  106 ) may couple the or each magnet  104  of the magnet system group  150  to the system support  102 . The group bearing device  116  may provide the magnets  104  with one or more than one translational degrees of freedom  111 , of which a first translational degree of freedom  111  may be along the reference direction  101  and/or one or more than one second translational degrees of freedom may be transverse to the reference direction  101 . 
     If one or more than one magnet system group  150  of the magnet system  100  is configured to be adjustable, or if the magnet system  100  has one or more than one adjustment device  150   s , the support structure  160  may have, e.g. per magnet system group  150 , a second carrier  202  (also referred to as a second magnet carrier/holder or as a group carrier) which couples the plurality of magnets  104  (cf. also  FIG.  2   ) to each other and/or to the adjustment device  150   s . In that case, the or each group carrier  202  may be magnetic (then providing the so-called return carrier) and the system carrier  102  may be non-magnetic. If the magnet system  100  does not have a group carrier  202 , the system carrier  102  may be magnetic (then providing the so-called return carrier). In some embodiments, the return carrier may be plate-shaped or include at least one plate (then also referred to as a return plate). 
     The actuator  106  may be configured to mechanically move the magnets  104  according to the or each translational degree of freedom  111  (also referred to as actuation). To this end, the actuator  106  may be coupled to the magnet  104  and/or the system support  102  such that when the actuator  106  is actuated, an attitude (i.e., orientation and/or position) of the magnet  104  relative to the system support  102  may be changed, e.g., according to a desired state. 
     To generate the motion, the actuator  106  may include an electromechanical transducer (e.g., an electric motor or piezoelectric actuator). The electromechanical transducer may be configured to generate translational motion (e.g., in the case of a linear electric motor) or to generate rotational motion (e.g., in the case of a rotary electric motor). To transmit motion to the magnets  104 , the actuator  106  may optionally include a gearbox (also referred to as an actuator). 
     To supply electrical power (also referred to as supply power) to the actuator  106  and/or to supply a communication signal to the actuator  106 , the actuator  106  may be coupled to one or more than one electrical line  108 . In principle, the communication signal and the supply power may be supplied together via one line  108 , but need not be. They may also be supplied via separate lines  108 . 
       FIG.  2    illustrates the magnet system  100  according to various embodiments  200  in a schematic perspective view. 
     According to various embodiments, the magnet system  100 , e.g., each of its magnet system groups  150 , may have a plurality of spatially separated magnet rows  204   a ,  204   i  mounted on (e.g., magnetically coupled to) a common group support  202 . Each of the magnet rows  204   a ,  204   i  may comprise a plurality of magnets of the same magnetization direction arranged in series one behind the other. At least the middle magnet row  204   i , which is arranged between two magnets of the outer magnet row  204   a , may be elongated in the reference direction  101 . 
       FIG.  3 A  illustrates a sputtering device  300  according to various embodiments in a schematic side view or cross-sectional view, and  FIG.  3 B  illustrates the magnet system  100  of the sputtering device  300  in a schematic detailed view  300   b.    
     The sputtering device  300  may include a bearing device  350  (also referred to as a target bearing device) for rotatably supporting a tubular target  302  (also referred to as a tube target). The target bearing device  350  may include one or more than one end block  312   a ,  312   b  by means of which the tubular target  302  may be rotatably supported, e.g., about an axis of rotation  311 , and/or fed. To this end, the target bearing device  350  (e.g., each end block  312   a ,  312   b ) may include one or more than one corresponding pivot bearing. Per rotary bearing, for example, a target coupling  301  (e.g., comprising a target connection flange) may be rotatably supported to which the tubular target  302  may be coupled. The axis of rotation  311  may be along reference direction  101 . 
     A first end block  312   a  of the target bearing device  350  may be configured as a drive end block  312   a , i.e., having a drive train  302   a  for rotating the tubular target  302 . A second end block  312   b  of the target bearing device  350  or the first end block  312   a  may be configured as a media end block  312   b , i.e., for supplying and discharging a cooling fluid (e.g., comprising water) and/or for supplying electrical power to the tubular cathode  302 . The cooling fluid may be directed through the tubular target  302 . 
     The drive train  302   a  may be coupled to or include a drive device (e.g., a motor) disposed outside of the drive end block  312   a . By means of the drive train  302   a , torque may be coupled to the tubular target  302  for driving rotational movement of the tubular target  302 . 
     Further, the sputtering device  300  may include the magnet system  100  held by the bearing device  350 , e.g., stationary and/or rotationally fixed relative to a direction of gravity. For example, the magnet system  100  may remain in a fixed orientation with respect to the direction of gravity as the tubular target  302  rotates (around the magnet system  100 ). 
     The bearing device  350  may comprise a rotatably mounted target coupling  301  per end block  312   a ,  312   b  by means of which the tubular target  302  may be coupled, for example, to the drive train  302   a  and/or to the cooling fluid supply (e.g., comprising one or more than one fluid line). For example, the target coupling  301  may include a releasable connection that may allow assembly and disassembly of the tubular target  302 . The target coupling  301  may further be penetrated by a fixed bearing, by means of which the magnet system  100  may be supported. 
     Detail view  300   b  illustrates an exemplary pair of magnet system assemblies  150 , each magnet system assembly comprising an assembly support  202 ; a plurality of magnets  104  coupled together (e.g., magnetically) by the assembly support  202 ; and an electrical actuator  106  configured to adjust the position of the assembly supports  202  and/or the magnets  104  relative to the system support  102  and/or relative to each other in response to the electrical communication signal supplied to the actuator  106 . For example, the actuator  106  includes an electric motor  106   m  and an optional actuating gear  106   g . The actuator  106   g  may couple the motor  106   m  to the group carrier  202 . 
     Further, the magnet system  100  may include an electrical generator  308  configured to supply electrical power (also referred to as supply power) or supply voltage to each of the actuators  106 . To this end, the line  108  may include one or more than one electrical supply lines  108   b  coupling the generator  308  to each of the actuators  106 . 
     Further, the line  108  may include one or more than one communication line  108   a  coupled to one of the end blocks by means of a communication interface. For example, the communication interface of the communication line  108   a  may be used to couple the communication signal from the end block. 
       FIG.  4    illustrates the magnet system  100  according to various embodiments  400  in a schematic side view or cross-sectional view (looking along the reference direction), in which the magnet system  100  includes a longitudinally extending magnet bar  352  (also referred to as a magnet bar). 
     The magnet bar  352  includes the support structure  160  and the plurality of magnets  104 , for example, the system support  102  and a magnet system group  150  or a plurality of magnet system groups  150  arranged in series (along the reference direction  101  or axis of rotation  311 ). 
     As exemplified, the system support  102  may comprise or consist of a sectional support, e.g., having a U-section, e.g., (as shown) a double U-section (also referred to as an H-section), or the like. The U-section (or double U-section) allows for high stability while providing sufficient installation space for one or more than one additional component  402  of the magnet system  100 . 
     Examples of the additional component  402  of the solenoid system  100  have: the actuator  150   s  or at least its actuator  106  and/or at least its group bearing device  116 , an electrical component  450  (e.g., a processor or other circuit, a generator  308 , an inverter, or the like). 
     In some, but not necessarily all, embodiments, the magnet system  100  includes a base frame  414  (also referred to as a bearing frame  414 ) and one or more than one support device  404 . The or each support device  404  may be mounted to the magnet bar  352  (e.g., the system support  102  thereof) and may be mated (e.g., interlocked) with the bearing frame  414  to form a bearing (e.g., floating bearing) for the magnet bar  352 . 
     According to various embodiments, the magnet system  100  comprises a housing  406   g  (illustratively a hollow body) having a housing interior  406   h  in which the magnet bar  352  is disposed, and an optional cold trap  408 . The cold trap  408  may be adjacent to or at least partially (i.e., partially or fully) disposed within the housing interior  406   h  and configured to dry the housing interior  406   h . For example, the cold trap  408  may include one or more than one fluid conduit  408   f , e.g., two or more (e.g., three, four, or more than four) fluid conduits  408   f , by means of which the cooling fluid is supplied to the target. 
     In a particularly simple and cost-effective implementation, the housing  406   g  is tubular (e.g., comprising a housing tube), e.g., having a circular cross-section and/or comprising a round tube. This increases the compactness and/or rigidity of the magnet system  100 . 
       FIG.  5    illustrates the magnet system  100  according to various embodiments  500  in a schematic side view or cross-sectional view, in which the magnet system  100  comprises a (e.g., fluid-tight, e.g., vacuum-tight) chamber  406  (also referred to as a system chamber  406 ) comprising the housing  406   g  and one or more than one cover  406   d  (also referred to as a connector cover  406   d  or housing cover  406   d ). The or each housing cover  406   d  may be configured to close (e.g., fluid-tight, e.g., vacuum-tight) the housing  406   g  end-to-end (e.g., from or in the reference direction  101 ). Optionally, at least one housing cover  406   d  of the system chamber  406  may be configured to supply the or each magnet system group  150  of the magnet system  100  (then also referred to as a supply cover), e.g., with the communication signal and/or with the supply power or supply voltage. To this end, the supply cover  406   d  may include a gear stage, a generator  308 , a communication interface, and/or a rotary coupling (e.g., a rotor through-coupling or a rotary union), as described in more detail below. 
       FIG.  6    illustrates the magnet system  100  according to various embodiments  600  in a schematic side view or cross-sectional view (looking along the reference direction  101 ). Once the system chamber  406  is assembled, the generator  308  may be electrically coupled to each magnet system assembly  150  when disposed within the housing  406   g . Further, the generator  308  may be coupled to the gear stage  804  (see  FIG.  8   ). Examples of components of the gear stage have: a planetary gear, an inner toothed rim, an outer toothed rim, and/or one or more than one other type of gear. 
     Generally, a gear stage herein refers to the wheel pairing between two gear wheels (also referred to as a driving gear wheel and a driven gear wheel) at which the speed or torque changes. Reference is made herein to a gear pair as an exemplary gear pair, it being understood that what is described in this regard may apply by analogy to any other type of gear pair. 
     The gear pair of the gear stage has two (e.g. toothed) gears as gear wheels (also referred to as first gear wheel and second gear wheel  708 ). The first gear may be arranged on the drive side, and the second gear  708  (more generally, a generator gear  708 ) may be arranged on the generator side. For example, the gear stage may include an external ring gear or a gear of a type other than a generator gear  708  that supplies torque to the generator  308 . For example, the gear stage (e.g., having at least 2 gears) may be configured as an internally geared gear stage, as will be described in more detail later. For example, the internally toothed gear stage may include at least 2 gears, one of which is internally toothed and the other of which is externally toothed. 
     When the tubular target  302  is rotated, the rotational motion of the tubular target  302  may be coupled to the generator  308  by means of the gear stage. The generator gear  708  may be coupled to a rotor of the generator  308  (also referred to as the generator rotor), such that the coupled rotational motion is transmitted to the generator rotor. 
     The or each gear stage of the solenoid system  100  may be configured to provide a greater speed on the generator side than is coupled to the gear stage on the drive side. 
       FIG.  7    illustrates the sputtering device  300  according to various embodiments  700  in a schematic circuit diagram. Six actuators  106  of the solenoid system  100  are illustrated here as an example, although their number may also be greater than or less than six. Optionally, the sputtering device  300  may include a control device  806  (for example, for drive control) that generates the communication signal. 
     It may be understood that communication between the control device  806  and an actuator  106  of the solenoid system  100  may be performed by means of the communication signal, for example bidirectionally (i.e., back and forth) or unidirectionally (i.e., only from the control device  806  to the actuator  106 ). In other words, the communication signal may be the carrier of an information transfer between the control device  806  and an actuator  106 . 
     The communication signal may illustratively be an electrical signal by means of which information may be transmitted (also referred to as communication), for example instructions or control data, measurement data, requests and/or responses. The communication by means of the communication signal may be, on a physical level, by means of an exchange of electrical power. The physical level of communication may be by means of physical transmitters. The communication by means of the communication signal may take place, on a logical level, by means of an exchange of information. The logical level of communication may take place by means of data processing, which may be implemented, for example, by means of a processor and/or a program and/or which controls the transmitters. The exchange of electrical power between the transmitters may, for example, be or become modulated according to the information to be transmitted. 
     For example, communication may be message-based (i.e., based on messages) according to a communication protocol (e.g., a network protocol). For example, a fieldbus network protocol may be used as the communication protocol. For example, a USB bus network protocol may be used as the communication protocol (Universal Serial Bus—USB). Of course, another communication protocol may also be used, which may be proprietary, for example. 
     For example, information transmitted from the control device  806  to the actuator  106  may represent the desired state that the actuator  106  is to assume. Information transmitted from an actuator  106  to the control device  806  may represent, for example, the actual state of the actuator  106  or an acknowledgement of receipt. 
     The communication line  108   a  may be coupled to the communication interface  602 . The communication interface  602  may be configured to exchange the communication signal between the control device  806  and one or more than one of the actuators  106 . In other words, the communication interface  602  may be configured to relay the communication signal. This may generally be accomplished using optical coupling, inductive coupling, and/or capacitive coupling. These achieve more reliable communication. Illustratively, optical, inductive, and/or capacitive relaying of the communication signal may provide galvanic isolation between the actuator  106  and the control device  806 . This galvanic isolation inhibits electrical interference during operation of the solenoid system  100 . 
     Optionally, the communication interface  602  may be configured such that the one or more than one communication channel is interrupted (i.e., opened) and established (i.e., closed), e.g., alternately interrupted and established, in time with the rotational movement of the tubular target. This causes the communication to be clocked according to the rotational motion of the target (i.e., in time with the rotational motion). This clocking achieves more reliable communication. Illustratively, interference originating in the rotational motion of the pipe target  302  may thus be systematic, making it easier to filter out. 
     It may be understood that this clocked communication may be implemented at the physical level of communication and/or at the logical level of communication. For example, the resistive, optical, inductive, and/or capacitive coupling may be physically interrupted (i.e., opened) and re-established (i.e., closed), e.g., alternately, in time with the rotational movement of the pipe target. Alternatively or additionally, logical communication (e.g., sending and/or receiving data or entire messages) may be clocked so that this is interrupted and re-established. 
     The generator  308  may be configured to generate the supply voltage during operation (for example, at the target rated speed) of the tubular target  302 . This supply voltage may be applied to all of the actuators  106  or, by means of a multiplexer, may be applied individually to only one of the actuators  106  at a time, which is actuated. When one of the actuators  106  is driven, the actuator  106  may receive corresponding electrical power from the generator  308 , which is applied for adjusting the magnetic field. 
     The magnet system  100  may optionally include one or more than one sensor  816  configured to capture the actual state (also referred to as the process state) of a sputtering process (e.g., coating process) provided by the sputtering device  300  and/or the magnetic field of the magnet system  100 . The control device  806  may be configured to drive the actuators  106  based on the process state. For example, actuating the actuators  106  may be based on a predetermined target state, such as such that a difference between the process state and the target state is reduced. 
     A sensor may be part of a measuring chain, which has a corresponding infrastructure (e.g. processor, storage medium and/or bus system or the like). The measurement chain may be configured to control the corresponding sensor, to process its captured measured variable as an input variable and, based on this, to provide an electrical signal as an output variable that represents the actual state of the input variable at the time of capture. The measurement chain may be or is implemented, for example, by means of the control device  806  (e.g., a programmable logic controller—SBS). 
     Various exemplary implementations of the housing cover  406   g , which facilitates the power supply and/or communication implementation described herein, are discussed below. 
       FIG.  8    illustrates the housing cover  406   d  of the magnet system  100  according to various embodiments  800  in a schematic cross-sectional view. Illustratively, the housing cover provides a cohesive assembly that is configured to provide power and/or electronic communications, and that better accommodates the geometric characteristics of the available installation space, maintenance requirements, and fluidic requirements. 
     Generally, the housing cover  406   d  has a (one-piece or multi-piece) mechanical carrier as the base body  802 , which carries the electronic communication and electrical power supply components. 
     The electrical power supply components include a gear stage  804 , a generator  308 , and a rotary coupling  850  that couples the gear stage  804  (e.g., its generator gear  708 ) to the generator  308 . The electronic communication components include a communication interface  602  and an electrical connector  862  that are coupled together (e.g., electrically conductive). 
     Various exemplary implementations of components of the housing cover  406   g  that facilitate the implementation of the magnet system  100  described herein are discussed below. 
     In an exemplary implementation of the generator  308 , the generator  308  may be elongated and/or extend away from the gear stage  804 . This improves the use of installation space. In an alternative or the exemplary implementation of the generator  308 , the generator  308  may include an additional gear stage  308   s  (compare  FIG.  9   ). This improves the generator efficiency. 
     In an exemplary implementation of the base body  802 , the base body  802  may include a flange  802   p  and a (e.g., peg-shaped) support device  802   v  that extends away from the flange  802   p  and/or is electrically conductive. The support device  802   v  and the flange  802   p  may be, for example, fixedly (e.g., rigidly) and/or electrically conductively coupled to each other. 
     The generator  308  may be fixedly (e.g., rigidly) connected, e.g., with its end face, to the base body  802 , e.g., its flange  802   p . Alternatively or additionally, the communication interface  602  may be fixedly (e.g., rigidly) connected to the base body  802 , e.g., its support device  802   v.    
     The base body  802  (also referred to as the cover base body) is disposed at least partially (e.g., at least its flange  802   p ) between the gear stage  804  and the generator  308 . The rotary coupling  850  allows an exchange of a rotary motion through a through-hole of the base body  802  (e.g., its flange  802   p ). 
     In an exemplary implementation of the electrical connector  862 , it may have one or more than one connector terminal and/or be coupled to one or more than one electrical communication line  108   a . Alternatively or additionally, the electrical terminal  862  may be electrically coupled, preferably ohmically, to the communication interface  602 , e.g., by means of the base body  802  (e.g., its flange  802   p  and/or its support device  802   v ). 
     The gear wheel  718  on the drive side may be supported on the base body  802 , e.g. its support device  802   v , by means of a rotary bearing  851 . Alternatively or additionally, the rotary coupling  850  may have a shaft  850   w  which is supported by means of a pivot bearing  851  on the main body  802 , e.g. its flange  802   p.    
     If the gear stage is internally toothed, its gear wheel  718  on the drive side has an inner toothed rim  718  (see also  FIG.  12   ). The inner toothed rim  718  illustratively provides a recess in which the generator gear  708  may be arranged. This saves installation space. 
       FIG.  9    illustrates the housing cover  406   d  of the magnet system  100  according to various embodiments  900  in a schematic perspective view in which the cover base body  802  includes one or more than one mounting area  904 ,  914 . 
     In an exemplary implementation, the flange  802   p  has one or more than one first mounting area  904 ,  914  (e.g., each having a through-hole). In an alternative implementation or the exemplary implementation, the support device  802   v  has a second mounting region  914  or at least extends through the communication interface  602 . 
     Each first mounting area  904  may be configured to mate with the housing  406   g  such that the lid base body may be mounted (e.g., fluid-tight) to the housing  406   g  (for axial attachment) using the first mounting area  904 . For example, the cover base body  802  may be bolted to the housing  406   g  using mounting screws  904   s  that extend through the through-holes in the cover base body  802 . The cover base body  802 , e.g., its flange  802   p , may further include a sealing surface  1002  facing the generator  308 . The sealing surface  1002  (e.g., having a groove for receiving a seal) may abut an elastomeric seal, for example, received in the groove. 
     The second mounting area  914  may be configured to match the target bearing device  350  such that the lid base body may be mounted to the target bearing device  350  (e.g., fluid-tight) by means of the second mounting area  914 , e.g., secured against rotation with respect thereto. 
     In an exemplary implementation, the communication interface  602  comprises an electrode  602   p  (e.g., comprising an electrically conductive material, e.g., metal), for example in the form of a plate electrode  602   p  and/or implementing a capacitor plate, for capacitive communication. This reduces the need to run a cable to the end block along the communication path and/or to hardwire them together. For example, the electrode  602   p  (also referred to as the communication electrode) may be configured for non-contact communication with the end block. 
     The gear stage  804  is configured to extract the rotational motion of the tubular target  302 . For this purpose, the gear stage  804  may have a torque support  804   d  (e.g., a driver) on the drive side, which is fixedly (e.g., rigidly) coupled to the gear wheel  718  (also referred to as the first gear wheel) of the gear stage  804  on the drive side. For example, the torque support  804   d  may comprise or consist of a pin. 
     The torque support  804   d , e.g. its pin, may be configured to match the target coupling  301  or the target  302  in such a way that they may engage with each other or at least exchange torque with each other during operation. 
     The torque support  804   d , e.g., the pivot thereof, may extend away from the generator  308  and/or the flange  802   p , e.g., past the communication interface  602 . Alternatively or additionally, the torque support  804   d , e.g., the pin thereof, may orbit the communication interface during operation. 
     The torque support  804   d , e.g., the pin thereof, may be spaced from an axis of rotation of the drive side gear wheel  718  of the gear stage  804  by a distance greater than one-half of an extent (e.g., diameter) of the communication interface  602 . Alternatively or additionally, the gear stage  804  may have a larger diameter than the communication interface  602 . This reduces the footprint of the assembly. 
       FIG.  10    illustrates the signal transmission chain of the housing cover  406   d , which includes the communication interface  602  and the electrical connector  862 , according to various embodiments  1000  in a schematic perspective view. 
     In an exemplary implementation of the communication interface  602 , the communication interface  602  may include a plurality of spatially separated (e.g., plate-shaped and/or electrically conductive) electrically conductive segments of an electrode, e.g., the plate electrode. For example, the plate electrode may be provided by means of a segmented and/or disk-shaped plate. 
     In an alternative or the exemplary implementation of the communication interface  602 , the communication interface  602  may include the (and optionally segmented and/or disk-shaped) communication electrode  602   p  (e.g., plate electrode) and a dielectric in which the electrode is embedded. For example, the communication electrode  602   p  may be encapsulated in the dielectric. For example, the communication interface  602  may comprise a fixed, electrically insulated communication disk as a plate electrode, the electrical transmission surface of which is, for example, discontinuous. 
     For example, the communication interface  602  is fixedly (e.g., rigidly) attached to and/or penetrated by the metallic support device  802   v.    
     For example, the electrical connection  862  may be electrically coupled, preferably ohmically coupled, to the communication electrode  602   p  of the communication interface  602 , e.g., by means of the support device  802   v . Alternatively or additionally, one or more than one communication line  108   a  may be electrically coupled, preferably ohmically, to the communication interface  602  (e.g., electrode thereof) by means of the electrical connector  862 . 
       FIG.  11    illustrates the generator side portion of the torque transmission chain of the housing cover  406   d  according to various embodiments  1100  in a schematic perspective view in which it comprises the generator  308 , the generator wheel  708 , and the rotary coupling  850 . Generally, the generator  308  may include an electromechanical converter  308  which includes, for example, a stator (also referred to as a generator stator) and a rotor (also referred to as a generator rotor). 
     The generator stator may be disposed or held stationary with respect to the system support  102  and/or the base body  802 . When the generator rotor is caused to rotate relative to the generator stator, the generator  308  may provide the supply voltage. The generator stator and/or the generator rotor may include a plurality of coils that generate the supply voltage (using induction). The other of the generator stator or generator rotor may include a plurality of magnets that excite the induction. 
     In an exemplary implementation of the generator  308 , it may be configured as a gear generator, i.e., have an additional gear stage  308   s  (also referred to as a generator gear stage) that couples the gear stage  804  (e.g., its generator gear  708 ) to the electromechanical converter  308   w  (e.g., its generator rotor). The generator gear stage  308   s  may be configured to provide a greater speed to the generator rotor than is coupled to the generator gear stage. 
     Alternatively, or in addition to the generator gear stage  308   s , the generator  308  may include a generator clutch. 
       FIG.  12    illustrates the drive-side gear wheel  718  according to various embodiments  1200  in a schematic perspective view, in which the gear wheel  718  has a running disk  1202  that couples the torque support  804   d  (e.g., the driver or pin) to the inner toothed rim  817  and is supported on the base body  802 , e.g., its support device  802   v , by means of the pivot bearing  851 . This reduces the required installation space. 
     The geometric characteristics of the available installation space within the housing  406   g  relate, for example, to the space conditions in the housing  406   g , according to which the generator  308  exerts as few structural restrictions as possible on the magnet bar  352  in terms of size and arrangement. The housing cover  406   d  is configured, for example, such that an inner gear stage  308   s  (e.g., the generator gear stage within the housing tube) and outer gear stage  804  are configured to provide the same position of the generator  308 ; provide reliable power generation based on target rotation; and provide a capacitor disk for communication that covers a large circular area, is water resistant, and is insulating to the outside; and, in the event of maintenance, does not require disassembly of the housing cover  406   g  and/or of the assemblies inside the housing  406   g  is necessary, or that the housing cover  406   d  may be completely replaced. This reduces the user&#39;s effort with respect to assembly and inspection procedures of the magnet system  100 . 
     In the following, various examples are described that relate to what has been described above and what is shown in the figures. 
     Example  1   a  is a housing cover (preferably configured according to any of examples 1 to 14), comprising: a first (e.g. non-magnetic) gear wheel (preferably comprising a recess) and a generator (e.g. comprising a gear stage), a (e.g. non-magnetic) flange, which is penetrated by a through-hole, is arranged between the first gear wheel and the generator and preferably has a sealing surface on a side facing the generator; wherein the generator (e.g. its stator), preferably its stator, is arranged between the first gear wheel and the generator, preferably on its front side, is coupled to the flange, and/or is rod-shaped; a second gear wheel, which is coupled to the first gear wheel (e.g. contacting it) and is preferably arranged in the recess of the first gear wheel; a rotary coupling (e.g. partly arranged in the through-hole), which couples the second gear wheel to the generator or is at least arranged in the recess of the first gear wheel to couple a torque of the second gear wheel to the generator therethrough; wherein the generator extends preferably away from the flange (e.g., in an axial direction) and/or rod-shaped, and a sealing surface, which is preferably arranged on a side facing the generator. at least configured to couple a rotational movement of the second gear wheel to the generator through the through-hole; wherein the generator preferably extends from the flange; an optional supporting device which is fixedly (e.g., rigidly) coupled to the flange and supports the first gear wheel, wherein the first gear wheel is preferably rotatably supported relative to (and/or around) the flange and/or the generator, e.g. by means of the optional supporting device; an optional electrical connection and an optional plate electrode between which said flange and/or said first gear wheel are arranged and which are electrically conductively, e.g. ohmically, connected to each other (for example by means of the optional electrical connection), wherein optionally the electrical connection is surrounded by the sealing surface; wherein the housing cover is preferably provided as a coherent assembly such that it may be mounted on or demounted from a housing as a whole. 
     Example 1 is a magnet system comprising: a (e.g. non-magnetic) housing having a housing interior; a (e.g. non-magnetic) magnet holder arranged in said housing interior and supported by means of said housing, preferably stationary with respect thereto; a (e.g. non-magnetic) housing cover (e.g. the housing cover according to example  1   a ), which together with the housing forms a fluid-tight chamber; wherein the housing cover comprises a gear stage, a generator and a rotary coupling that couples the gear stage to the generator. 
     Example 2 is the magnet system according to example 1, wherein the housing cover comprises a (e.g. non-magnetic) flange which is arranged between the gear stage and the generator, wherein the rotary coupling couples the gear stage and generator together through the flange. 
     Example 3 is the magnet system according to example 2, wherein the housing cover has a pivot bearing by means of which a drive-side gear wheel (e.g. first gear wheel) of the gear stage is coupled to the flange. 
     Example 4 is the magnet system according to any of examples 1 to 3, wherein the gear stage comprises a generator-side gear wheel (e.g., second gear wheel) contacting the drive-side gear wheel and/or the rotary coupling. 
     Example 5 is the magnet system according to example 1 or 4, wherein the housing cover comprises a drive-side drive coupling which is configured to transmit torque to the gear stage and/or which is carried by the gear stage. 
     Example 6 is the magnet system of example 5, wherein a drive side gear wheel of the gear stage is fixedly coupled to the drive coupling; and/or wherein the drive coupling includes a torque support (e.g., carrier) attached to the gear stage (e.g., its drive side gear wheel). 
     Example 7 is the magnet system of example 6, with the torque support extending away from the generator. 
     Example 8 is the magnet system according to example 1 or 7, wherein the gear stage has an inner toothed rim as the drive-side (or first gear wheel) gear wheel, and/or wherein the gear stage has an outer toothed rim as the generator-side (or second gear wheel) gear wheel. 
     Example 9 is the magnet system according to any of examples 1 to 8, wherein the housing cover includes a communication interface that is fixedly coupled to the generator, the gear stage being disposed between the generator and the communication interface. 
     Example 10 is the magnet system according to example 9, wherein the communication interface comprises or consists of a (preferably encapsulated and/or segmented) plate electrode, which is preferably configured to form a capacitive rotary contact; and/or wherein the housing cover comprises an electrical terminal, which is arranged facing the generator (e.g. on a generator facing side of the flange) and is electrically conductively coupled, preferably ohmically, to the communication interface (e.g. its plate electrode). 
     Example 11 is the magnet system according to example 10, where the plate electrode is encapsulated by means of a dielectric (e.g. as part of the communication interface). This improves the service life. 
     Example 12 is the magnet system according to any one of examples 1 to 11, further comprising: an actuator electrically powered by means of the generator and having a control input conductively, preferably ohmically, coupled to the housing cover (e.g. its flange, electrical connection and/or communication interface). 
     Example 13 is the magnet system according to any one of examples 1 to 12, further comprising: at least one magnet coupled to the magnet holder by means of the actuator and disposed in the housing interior, wherein the actuator is configured to change a position of the magnet relative to the magnet holder in response to an electrical communication signal supplied to the control input by means of the rotary coupling. 
     Example 14 is the magnet system according to any of examples 1 to 13, wherein the rotary coupling comprises a rotatably mounted shaft that couples a generator-side gear wheel of the gear stage (e.g., fixedly) to the generator. 
     Example 15 is a sputtering device comprising: a bearing device, preferably comprising one or more than one end block, for rotatably supporting a sputtering target; the magnet system according to any one of examples 1 to 13 being fixedly supported (e.g. relative thereto and/or relative to a gravitational direction) within the sputtering target by means of the bearing device. 
     Example 16 is the sputtering device of example 15, the bearing device further comprising: a fixed bearing supporting the magnet system; and/or a rotary bearing for rotatably supporting the sputtering target. 
     Example 17 is the sputtering device of example 16, the bearing device further comprising: a coupling rotatably supported by the pivot bearing for coupling the sputtering target, the coupling having a through-hole into which the fixed bearing extends.