Online adjustment of magnet bars in a magnetron

Abstract

Disclosed are a control assembly (100) for controlling a magnetic structure (111) of a magnetron sputtering apparatus, an inline sputtering coating apparatus (400) comprising the same, and an associated coating method (500). The assembly (100) comprises an elongated support structure (150), at least one control unit (130) coupled thereto, at least one memory device (140), and at least one actuator (120a-d) for locally adjusting the position and / or orientation of the magnetic structure. An input connector (32) of the control unit (130) is operably connectable to trigger units (432; 433; 434; 440a-c) located away from the assembly. The control unit is configured to load a control input from the memory device, determine a control trajectory for an actuator based on the control input, generate a control signal sequence for the actuator according to the control trajectory, and synchronize the transmission of the control signal sequence to the actuator driver circuit (127) with at least one trigger signal from the trigger unit.

Description

[Technical Field]

[0001] The present invention relates to the field of magnetron sputtering processes, magnetron sputtering equipment, and coatings obtained thereby. More specifically, the present invention relates to a control assembly for a magnetic structure in a magnetron that can be dynamically adjusted. [Background technology]

[0002] Magnetron sputtering is a material layer deposition technique that uses the plasma confinement effect of a magnetic field tunnel to achieve high plasma density and associated sputter deposition rates. Sputter coating equipment has been successfully adapted to meet the industrial need for coating large-area substrates in a short time, and has also achieved good control over film properties such as thickness uniformity. Therefore, many industries, from flat panel display technology (LCD or OLED or touch technology) to low-emission and anti-reflective glass coatings, rely on magnetron sputtering technology during product manufacturing. Continuous sputter coating by in-line deposition systems, where the substrate moves against the sputtering target, offers the advantages of high throughput and flexibility. Complex coating stacks, such as multilayer coatings with varying numbers of coating layers and / or different coating layer compositions, can be reliably sputtered onto a moving substrate that is transported across multiple sputtering targets arranged in the same or different deposition chambers along the coating line.

[0003] It has proven useful to provide a magnetron that can locally tune the magnetic structure without requiring ventilation of the coating apparatus, so that the resulting magnetic field and the imperfections of the resulting plasma racetrack can be more efficiently corrected before and during production campaigns, as well as the erosion profile of the sputter target surface can be compensated for in an automated manner. The primary objective of locally tuning the magnetic structure is to control and improve the uniformity of layer characteristics (e.g., thickness) across the moving substrate.

[0004] Document WO2015 / 167687A1 (SPUTTERING COMPONENTS INC [US]), dated November 5, 2015, discloses a magnetron assembly comprising an elongated support structure, a magnet bar structure movably positioned below the support structure, and a plurality of drive modules having motor-driven actuation mechanisms coupled to the support structure. An electronic controller and a rechargeable battery module are coupled to the support structure and communicate operably with the drive modules. The battery is configured to energize each motor-driven actuation mechanism and the electronic controller and is recharged by a generator module coupled to the support structure.

[0005] Document EP3963620A1 (INTERPANE ENTW UND BERATUNGSGESELLSCHAFT MBH[DE]), dated March 9, 2022, discloses a magnetron assembly comprising multiple magnets mounted on multiple yokes. The actuation mechanism is mounted along an elongated support bar, and a drive module for the actuation mechanism is configured to individually displace the yokes away from and / or toward the elongated support bar. An external controller with a processor, located outside the vacuum chamber, is configured to automatically determine the position of each of the multiple yokes based on parameters defining the coating profile of the substrate. A signal including the determined yoke position is transmitted from the external controller to the magnetron assembly via an optical interface fiber, and a master controller within the magnetron assembly receives the signal from the optical interface fiber and transmits it to multiple slave controllers that operably communicate with the multiple drive modules. A rechargeable battery that operably communicates with the drive modules is configured to power the actuation mechanism, the slave controllers, and the master controller.

[0006] The documents mentioned above state that the tuning rate of the magnetic structure inside the magnetron assembly is still limited, and that rechargeable batteries may need to be replaced periodically due to their finite cycle life.

[0007] Therefore, it is desirable to further reduce the tuning rate limit in online tunable magnet bar assemblies. [Overview of the project]

[0008] While not recognized as a bottleneck in simple sputter coating applications, the inventors have found that the limited amount and rate of data transferred via a dedicated communication interface between the magnet bar assembly and the connected end block (outside the magnet bar assembly) negatively impacts sputter coating applications where complex dynamic tuning of the magnetic structure is desired. Complex tuning patterns may be required to ensure good uniform coating on moving 3D-shaped or curved substrates. Therefore, it is desirable to have a non-conflicting solution that can provide a tuning parameter sequence in a robust and reliable manner without excessive load on the communication interface.

[0009] An object of embodiments of the present invention is to provide a device and method for a magnetron that enables online tuning of a magnet bar at a higher control rate.

[0010] The above objectives are achieved by the assembly, apparatus, and method according to the present invention.

[0011] In a first aspect, the present invention relates to a control assembly for controlling a magnetic structure of a magnetron sputtering apparatus. The assembly is connectable to the end block of the magnetron sputtering apparatus and comprises an elongated support structure having a longitudinal axis. The control assembly coupled to the support structure further comprises at least one control unit, at least one storage device, and at least one actuator for locally adjusting the position and / or orientation of the magnetic structure when operably coupled to at least one actuator. The input connector of at least one control unit is operably connectable to a trigger unit located away from the control assembly. Furthermore, at least one control unit, Loading a control input from at least one storage device, wherein the control input includes a setpoint for at least one actuator, or data necessary for calculating a setpoint for at least one actuator. Based on the loaded control input, determine the control trajectory for at least one actuator, To generate a control signal or control signal sequence for at least one actuator according to a control trajectory, The system is configured to synchronize the transmission of a control signal or control signal sequence to the driver circuit of at least one actuator with at least one trigger signal from a trigger unit.

[0012] The trigger signal, which synchronizes with the control signal transmission, indicates the position of the substrate relative to the magnetic structure.

[0013] Here, the trigger signal indicates the position of the substrate relative to the magnetic structure and means transmitting substrate position information or substrate position data that is embedded in the trigger signal or can be derived from the trigger signal itself. In embodiments of the present invention, this includes providing hints to the substrate position that can be derived from the trigger signal itself or are implied by the trigger signal itself, without the transmission of substrate position information as part of the content of the trigger signal, e.g., substrate position information encoded in the trigger signal, and without the actual explicit transmission of substrate position data by the trigger signal. In the former case, the position information is carried by the trigger signal and can be represented in or converted to a local coordinate system of the magnetic structure. In the latter case, the trigger signal itself, i.e., the entire signal identified as a trigger signal issued by a trigger unit, rather than the content carried by the trigger signal, provides hints about where the substrate can be found at that particular moment without requiring the transmission of substrate position data as an explicit content of the trigger signal. In embodiments of the present invention, hints to the substrate position can be derived from the trigger signal by emitting a trigger signal when the trigger unit responds to the presence of the substrate at a particular position relative to the magnetic structure, and by analyzing the trigger signal when the trigger unit is identified as the source of the trigger signal. For example, a trigger signal may correspond to a message, a trigger unit may be identified within the source field of the message, or a trigger unit as the source of a trigger signal may be essentially represented through the inherent format, duration, variation, or any other suitable signal characteristics of the trigger signal.

[0014] The present invention further relates to a magnetron sputtering apparatus for sputter coating of non-planar substrates, and an in-line vacuum sputtering coating apparatus for generating repeatable and reproducible coating profiles on a moving substrate, the apparatus comprising a control assembly according to a first embodiment.

[0015] In embodiments of the present invention, the magnetron sputtering apparatus is adapted to accept a cylindrical target.

[0016] In yet another aspect, the present invention relates to a method for sputter coating a moving substrate using a magnet bar assembly for a magnetron sputtering apparatus. The magnet bar assembly comprises at least one actuator for locally adjusting the position and / or orientation of the elongated magnetic structure of the magnet bar assembly. This method, A step of storing control inputs in a storage device disposed inside a magnet bar assembly, wherein the control inputs include set points for at least one actuator or data necessary for calculating set points for at least one actuator. The steps include loading control inputs from a memory device to a control unit located inside the magnet bar assembly, The steps include receiving an external trigger signal from a remotely located trigger unit on the magnet bar assembly, The steps include: executing a control program on a control unit to determine a control trajectory for at least one actuator based on the control input; generating a control signal or control signal sequence for at least one actuator according to the control trajectory; and synchronizing the transmission of the control signal or control signal sequence to the driver circuit of at least one actuator with an external trigger signal. The process includes the step of adjusting the position and / or orientation of a magnetic structure while sputter coating a moving substrate by driving at least one actuator according to a control signal or a sequence of control signals.

[0017] An advantage of the embodiments of the present invention is that they provide a robust and reliable tuning parameter sequence without excessive load on the communication interface.

[0018] In an embodiment of the present invention, a control trajectory for each control assembly actuator includes at least one regulated position of the actuator, and typically includes a list of regulated positions of the actuator over an exposure interval associated with the moving substrate to be coated. Similarly, the control unit generates at least one control signal according to the control trajectory for the actuator, and typically generates a control signal sequence according to the control trajectory for the actuator.

[0019] According to some embodiments of the present invention, the support structure may include or consist of a hollow tubular support element, an extruded profile, a bent sheet metal part, or a combination of an extruded profile and curved sheet metal.

[0020] In some embodiments of the present invention, the support structure provides a fluid-tight housing for a magnetic structure, an electronic component including a control unit, a memory device, a driver circuit and associated actuators, and other optional components (e.g., a receiver circuit), and protects them from damage and corrosion. The support structure may be adapted to distribute a coolant fluid over the entire length of the support structure, for example, by means of a fluid-tight duct disposed inside the outer peripheral wall of the support structure.

[0021] According to some embodiments of the present invention, the magnet bar assembly is formed when the magnetic structure is coupled to the control assembly. This coupling may be, for example, an indirect coupling via one or more actuators of the control assembly. In such an embodiment of the present invention, the magnetic structure is directly or indirectly mounted to the control assembly actuator.

[0022] According to some embodiments of the present invention, the magnetic structure may include a magnetic pole piece or a non-magnetic piece as a carrier structure on which an array of magnets is placed. These arrays of magnets may be arranged in rows across the central portion of the longitudinally extending magnetic structure. Preferably, the central row of magnets is located on the sides of the two peripheral rows of magnets, and the orientation of the magnetic poles of the magnets in the central row is opposite to the orientation of the magnetic poles of the magnets in the peripheral rows. The control assembly actuator may be coupled or attached to the magnetic pole piece or the non-magnetic carrier so as to cause local deformation of the magnetic pole piece or the non-magnetic carrier. The gear reduction ratio associated with the control assembly actuator may be advantageously reduced when deforming a non-magnetic carrier or a holding structure for the magnets of the magnetic structure, or when moving, for example, lifting the magnets of the magnetic structure relative to this non-magnetic carrier.

[0023] According to some embodiments of the present invention, the magnetic structure may include a plurality of segments. The segmentation of the magnetic structure may be in the longitudinal direction (e.g., the direction corresponding to the elongation axis of the support structure), the crossing direction (e.g., the direction perpendicular to the elongation axis of the support structure), the diagonal direction, the transverse direction, or any combination thereof. Further, this segmentation may be limited to a specific zone (e.g., end zone, middle zone) of the magnetic structure or may extend to all zones of the magnetic structure. The individual segments of the magnetic structure may be locally actuated by the corresponding actuators of the control assembly.

[0024] According to the same or different embodiments of the present invention, the magnetic structure may be subdivided into a plurality of elongated sections or strips such that each elongated section of the magnetic structure has its own magnetic or non-magnetic carrier on which one of the magnets of the magnet array, e.g., a central magnet or one of the magnets in the peripheral magnet rows, is placed.

[0025] Actuators of a control assembly can act on different sections of a magnetic structure to locally change the position and / or orientation of each within one or more tuning points, for example, along the longitudinal axis of a support structure. For each tuning point, a separate actuator of the control assembly may be provided for each of the different segments of the magnetic structure to locally change the position and / or orientation of the segment. Alternatively, a single actuator of the control assembly may be provided for each of the different segments of the magnetic structure, for example, along the longitudinal axis of a support structure, to locally change the position of the segment, and a hinge system may be coupled to this actuator to further allow tilting movement of the different segments of the magnetic structure relative to each other.

[0026] According to some embodiments of the present invention, at least one control unit comprises a processing unit as a subunit or is operably coupled to a processing unit in a control assembly. The processing unit may be used to perform computational tasks such as applying a conversion function to a loaded setpoint, adjusting a control trajectory, or calculating a setpoint from grid data related to substrate characteristics or type (e.g., topographic substrate data), thereby reducing the computational load on the control unit. More specifically, to enable adjustment of the control trajectory, at least one control unit may be further configured to load a record of one or more process variables related to a magnetron sputtering apparatus from at least one storage device or from a trigger unit via an input connector, and to adjust the control trajectory based on the record of the one or more process variables. This adjustment may be performed directly on the record value as input, or via intermediate calculation results obtained from the record value in combination with summation input data.

[0027] According to some embodiments, some of the electronic components, including control units, memory devices, processing units, and / or driver circuits, may be assembled on the same circuit board or embedded within the same electronic package.

[0028] According to some embodiments of the present invention, the electric components of a control assembly, such as a driver circuit, an electrically driven actuator, at least one control unit, and a memory device, may be energized by a power line, such as a single electric wire or wire bundle, extending between the control assembly and an end block system to which the control assembly can be connected. Preferably, power line modulation technology is also used to enable data exchange between at least one control unit of the control assembly and the end block system. This reduces the amount of wired connections and / or communication interface modules (e.g., transceivers or transmitter / receiver modules) between the control assembly and the end block system.

[0029] In embodiments of the present invention, the trigger unit may be a sensor unit, such as an event-triggered sensor unit, such as a substrate position or speed sensor. In another embodiment of the present invention, the trigger unit may be a part of a deposit chamber, such as a valve in an inlet or outlet slit that can generate a trigger signal when it is switched or reaches a predetermined state, such as an open state. In yet another embodiment of the present invention, the trigger unit may be a part of a substrate transport system, such as a robot arm that carries the substrate, or a position sensor in a motor of the transport system.

[0030] The trigger signal may transmit absolute substrate position data to at least one control unit, or may include data that enables at least one control unit to derive the position of the substrate relative to the control assembly. In some embodiments of the present invention, at least one control unit may be configured to extract substrate position information from the trigger signal. Additionally or alternatively, at least one control unit may be configured to extract source information from the trigger signal, correlate the source information with the position of the moving substrate, or extract the position of the moving substrate from the source information. The trigger signal may correspond to a clearly defined position of the substrate, for example, a homing signal. Additional information, such as substrate speed information and / or current process parameters and equipment settings, may be included in or derived from the trigger signal.

[0031] In embodiments of the present invention, the complexity of the trigger signal can range from interrupt requests, e.g., a single pulse, to signal sequences, e.g., pulse sequences, implementing a predetermined data format, or conforming to a communication protocol.

[0032] At least one control unit may be configured to determine a time reference for the transmission of control signals from board velocity information or board trajectory data, which at least one control unit loads from at least one storage device or extracts from a trigger signal.

[0033] In embodiments of the present invention, at least one control unit may be configured to determine the time interval between transmissions of consecutive control signals based on pre-calculated substrate trajectory data accessible on at least one storage device, or based on one or more received trigger signals. The pre-calculated substrate trajectory defines waypoints (substrate positions) that are combined with substrate velocity information or transit time included in the pre-calculated substrate trajectory or trigger signal.

[0034] In embodiments of the present invention, at least one control unit may synchronize the transmission of a first control signal with a trigger signal, or, in the case of a recursive control sequence, the transmission of any one of the control signals in the sequence. Advantageously, the transmission of multiple control signals is synchronized by the control unit with a trigger signal or a trigger signal sequence. This improves the synchronization between the online adjustment of the magnetic structure and the movement of the substrate. Synchronization by at least one control unit may include determining one or more delays in the transmission of one or more control signals in relation to the control unit's reception of a trigger signal event or trigger signal.

[0035] In embodiments of the present invention, control inputs stored on at least one storage device may be setpoints or lists of setpoints relating to each control assembly actuator. Control inputs, more specifically actuator setpoints, may be organized into a table or table-like data structure, e.g., a lookup table. Metadata or unique identifiers may be associated with each of the tables or table-like data structures stored on at least one storage device, linking the tables or table-like data structures to sputtering process parameters, sputtering equipment parameters, and / or substrate parameters, or specific combinations of ranges of such parameters. At least one control unit may access the control inputs in the tables or table-like data structures based on the metadata or unique identifiers. In particular embodiments of the present invention, at least a portion of the current sputtering process parameters may be encoded in a trigger signal generated by a trigger unit and transmitted by that trigger signal, thereby enabling the control unit to retrieve the appropriate control inputs from at least one storage device.

[0036] In embodiments of the present invention, at least one control unit may apply a transformation to a control input loaded from at least one storage device. The applied transformation optimizes the control trajectory with respect to additional input variables such as substrate-related information (e.g., size, orientation, curvature values ​​and / or topographic mapping) and / or processing conditions. In such embodiments, at least one control unit is configured to extract additional input variables from a trigger signal, extract additional input variables from an external data frame communicated to the control unit, or retrieve additional input variables from at least one storage device if available.

[0037] At least one control unit may compare a trigger signal, a unique identifier obtained from the trigger signal and / or source information, with a corresponding entry in a table-like structure stored on at least one storage device, and retrieve the actuator setpoint associated with the matching entry.

[0038] An advantage of the embodiments of the present invention is that the amount of external data transmitted through a noisy communication link between the control unit of the control assembly and the end block associated with the control assembly can be reduced.

[0039] An advantage of the embodiments of the present invention is that high-frequency signals can be used for communication between components of the control assembly, compared to the low-frequency signals available for communication between the end block and the magnet bar assembly in conventional magnetrons. This enables data exchange at higher transfer rates between electronic components inside the control assembly, for example, between the control unit and the driver circuit, and between the control unit and the memory device. In fact, the support structure can form a protective enclosure for the electronic components of the control assembly, and advantageously, it acts as an electromagnetic Faraday cage against noise interference from the power supply and plasma. Thus, excessive shielding of the wiring between electronic components inside the control assembly is no longer required.

[0040] An advantage of the embodiments of the present invention is that the control signals transmitted to the driver circuits of the actuators in the control assembly are generated by the control unit within the control assembly and propagate only on signaling means located within the control assembly. Communication with external devices, particularly external devices located outside the vacuum chamber of the sputtering apparatus, is not required. Therefore, the control signals related to the local autonomous adjustment of the magnetic structure along the magnet bar no longer need to originate from outside the control assembly, i.e., from the magnet bar, magnetron, end block, or even outside the vacuum chamber, but can be generated inside the magnet bar and distributed in situ. No external information is required to autonomously adjust the magnetic structure.

[0041] A further advantage of the embodiments of the present invention is that control signals can be defined, generated, and transmitted within a large bandwidth within the magnet bar. Furthermore, high-bandwidth communication channels, such as connectors, between the magnet bar and the end block, or between the magnet bar and the outside of the vacuum chamber, are no longer required.

[0042] An advantage of the embodiments of the present invention is that the actuator of the control assembly can regulate the substrate in real time during sputter coating. This makes it possible to uniformly coat a substrate having a curved coating surface.

[0043] An advantage of the embodiments of the present invention is that multiple substrates of different heights (thicknesses) or surface orientations can be sputter coated in parallel, for example, when mounted on a common transport frame or arranged in rows substantially parallel to the length axis of a rotating target.

[0044] An advantage of the embodiments of the present invention is that control inputs, such as actuator setpoints, can be converted in place by the control unit, and / or the control trajectories for the actuators of the control assembly can be adjusted in place by the control unit. This makes it possible to efficiently perform calibration and feedback control operations.

[0045] An advantage of the embodiments of the present invention is that the control trajectory can be easily updated or readjusted under any changes in sputtering process conditions, equipment settings, and / or substrate characteristics. This reduces the time required to adjust the sputtering process for optimization in a new process, to adjust the sputtering process at the start of a new production campaign, or to adapt the sputtering equipment to changes in product or substrate shape during one same production campaign.

[0046] An advantage of the embodiments of the present invention is that the coating layer can be uniformly deposited on a large area of ​​a substrate or workpiece that is non-flat, for example, curved, or has a varying height profile, or is mounted at an angle to the substrate carrier plane or substrate transport direction. Typical width and length dimensions of a large-area (curved) substrate are, for example, 0.15*0.3m 2 , 0.3*0.4m 2 , 1.1*1.3m 2 , 1.5*1.8m 2 , 1.0*3.0m 2 , 2.0*2.0m 2 , 2.0*3.0m 2 , or up to 3.5*6.5m 2 A further advantage of the embodiments of the present invention is that the thickness of the deposited layer on a large-area, non-flat, or inclined substrate can be precisely controlled, for example, to within + / -5%, for example, within + / -3%, or even within + / -1%.

[0047] Specific and preferred embodiments of the present invention are described in the attached independent and dependent claims. Features from the dependent claims may be a combination of features from the independent claims and features from other dependent claims, and are not merely expressly described in the claims.

[0048] For the purpose of summarizing the advantages achieved by the present invention over the prior art, specific purposes and advantages of the present invention are described herein above. Naturally, it will be understood that not all such purposes or advantages can be achieved according to any particular embodiment of the present invention. Accordingly, for example, those skilled in the art will recognize that the present invention can be embodied or implemented in a manner that achieves or optimizes one advantage or group of advantages as taught herein, without necessarily achieving other purposes or advantages as taught or suggested herein.

[0049] The above-described and other embodiments of the present invention will become apparent and clarified by referring to the embodiments described below. [Brief explanation of the drawing]

[0050] Herein, the present invention will be further described with reference to the accompanying drawings, by example.

[0051] [Figure 1] This is a cross-sectional view of a control assembly having a magnetic structure according to one embodiment of the present invention. [Figure 2] This is an enlarged view of the control assembly in Figure 1, showing more detail. [Figure 3] This is an enlarged view of the control assembly in Figure 1, showing more detail. [Figure 4] This is a cross-sectional view of an in-line sputtering coating apparatus equipped with a control assembly according to an embodiment of the present invention. [Figure 5] Steps of a coating method using a control assembly for a magnetron magnetic structure according to an embodiment of the present invention are illustrated. [Figure 6]Steps of a method for updating a control trajectory, which can be used in embodiments of the present invention, are illustrated below.

[0052] The drawings are for illustrative purposes only and are not limiting. In the drawings, some dimensions of elements may be exaggerated for illustrative purposes and may not be drawn to scale. Dimensions and relative dimensions do not necessarily correspond to actual implementation of the invention.

[0053] No reference numeral in a claim should be construed as limiting in scope.

[0054] In different drawings, the same reference numeral refers to the same or similar element. [Modes for carrying out the invention]

[0055] The present invention is described with respect to specific embodiments and specific drawings, but is not limited thereto and is limited only by the claims.

[0056] The terms "first," "second," etc., used in this description and claims are used to distinguish similar elements and are not necessarily used to describe order in any temporal, spatial, sequential, or any other manner. It should be understood that such terms are interchangeable under appropriate circumstances, and that embodiments of the invention described herein may operate in an order other than those described or illustrated herein.

[0057] It should be noted that the term “comprising” as used in the claims should not be construed as being limited to the means enumerated thereafter, nor as excluding other elements or steps. Therefore, it should be interpreted as specifying the presence of the described features, integers, steps, or components as mentioned, but not as excluding the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Accordingly, the scope of the expression “a device comprising means A and B” should not be limited to a device consisting solely of components A and B. It means, with respect to the present invention, that only the relevant components of the device are A and B.

[0058] Throughout this specification, any reference to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in relation to an embodiment is included in at least one embodiment of the present invention. Therefore, the occurrence of the phrase “in one embodiment” or “in an embodiment” in various places throughout this specification does not necessarily refer to the same embodiment. Furthermore, as will be apparent to those skilled in the art from this disclosure, in one or more embodiments, a particular feature, structure, or characteristic may be combined in any preferred manner.

[0059] Similarly, in the description of exemplary embodiments of the present invention, various features of the invention may be summarized in a single embodiment, figure, or description for the purpose of simplifying this disclosure and aiding in the understanding of one or more of the various embodiments of the invention. However, this method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than those explicitly enumerated in each claim. Rather, as reflected in the following claims, the embodiments of the invention are fewer than all the features of a single, aforementioned disclosed embodiment. Thus, the claims following the detailed description are explicitly incorporated into this detailed description, and each claim constitutes a separate embodiment of the invention in itself.

[0060] Furthermore, some embodiments described herein include some features included in other embodiments but do not include other features, and as will be understood by those skilled in the art, combinations of features of different embodiments are within the scope of the present invention and constitute different embodiments.

[0061] Numerous specific details are provided in the description herein. However, it is understood that embodiments of the present invention may be carried out without these specific details. In other instances, well-known methods, structures, and techniques are not described in detail so as not to obscure the understanding of this description.

[0062] In the context of the present invention, the non-flat substrate surface to be coated comprises at least one non-zero principal curvature and the associated directions of the principal curvatures. This also encompasses substrate surfaces or surface parts whose shape changes in discrete steps, for example, which can define a discrete approximation in the direction of the principal curvatures. The backside of the substrate to be coated need not be curved, i.e., it can be flat. Acute or obtuse angles, for example, edges between other flat but in some cases inclined surface parts of the substrate are considered surfaces with localized infinite curvature and also fall within the scope of the present invention. Examples are polyhedral surfaces or meshes made from sets of triangles, quadrilaterals, etc., which can approximate a smooth surface.

[0063] The design of windshields, sunroofs, large display panels, and dashboards in the automotive sector often uses complex shapes featuring non-flat curved surface geometries. Ultra-wide computer screens with curved display areas are also commercially available. These curved or non-flat substrate surfaces, as with conventional flat substrates, are also usually equipped with anti-reflection coatings, protective coatings, etc. The large areas of substrates or workpieces for which a coating layer needs to be deposited uniformly are impressive in these applications, for example, 0.15 * 0.3 m 2 , 0.3 * 0.4 m 2 , 1.1 * 1.3 m 2 , 1.5 * 1.8 m 2 , 1.0 * 3.0 m 2 , 2.0 * 2.0 m 2 , 2.0 * 3.0 m 2 or up to 3.5 * 6.5 m 2 and not only are there strict tolerances for the uniformity of the layer thickness. It is not uncommon for product manufacturers to require magnetron sputtering equipment that can accurately control the deposited layer thickness on the substrate within + / −5% or less, for example, + / −3% or + / −1%. Curved geometries and complex substrate shapes that require a uniform coating make the precise control of the coating layer thickness uniformity in magnetron sputtering equipment even more difficult.

[0064] Historically, sputter coatings for these applications were deposited on flat substrates before the bending process. More recently, the substrate to be coated may be pre-bent and processed, and the coating is then performed on the curved substrate. The uniformity of the coating layer thickness can, in principle, be controlled by local tuning of the magnet bar inside the magnetron. However, the relatively high speed at which the substrate is transported through the deposition chamber of the in-line coater, e.g., on the order of meters per minute, often exceeds the tuning capability of conventional magnetons, where the control data is transmitted through a noisy communication channel that relays the magnet bar assembly to an external control device outside the end block and vacuum chamber. This limits the rate at which the control data can be communicated to the actuator of the tunable magnet bar assembly. Embodiments of the present invention described herein solve the problem of the limited transfer rate of control data that needs to be communicated to the actuator inside the magnet bar assembly.

[0065] Figure 1 shows a cross-sectional view of a control assembly for the magnetic structure of a magnet bar. The control assembly 100 comprises an elongated support structure 150 in the form of a tubular housing, a control unit 130, a memory device 140, and actuators 120a-d for locally adjusting the position and / or orientation of the magnetic structure 110. The control unit 130, the memory device 140, and the actuators 120a-d are disposed inside the elongated support structure 150 and coupled to the support structure 150, for example, so as to have a fixed longitudinal position on the central axis of the tubular support structure.

[0066] The elongated support structure may be provided in many different forms and shapes, but is not limited to, extruded profiles, hollow tubes or pipes, rolled metal sheets, or combinations thereof. The control unit 130, the memory device 140, and one or more of the actuators 120a-d may be securely mounted to mounting plates, for example, screwed into, fastened to the outer or inner wall of the support structure. The outer and inner walls may be arranged to divide the internal volume of the support structure into a plurality of longitudinally extending cavities or compartments. At least some of the compartments are isolated from the fluid path of the coolant fluid and thus protect the electronic components from corrosion and electrically insulate them from high absolute voltages (e.g., above 200V, typically above 300V such as 400V, and up to 1000V under special conditions) when supplying high power to the target of the magnetron sputtering apparatus under sputtering conditions. In this embodiment, the elongated support structure includes at least one such compartment 153. The end pieces 151, 152, for example, end caps or disks, are mounted on each end of the support structure 150 to completely shield the inside of the support structure, which can operate under atmospheric pressure conditions, from the ambient vacuum conditions that typically govern the inside of the deposition chamber containing the magnet bar to which the support structure belongs. When mounted inside the support structure 150, the magnetic structure 110 and the control assembly 100 together form a magnet bar assembly that can be used in a magnetron sputtering apparatus or magnetron sputtering coating system.

[0067] In this embodiment, the magnetic structure 110 includes, for example, pole pieces 113 made of soft iron or other permeable material (e.g., nickel, cobalt, etc.), an inner or central array of magnets 111, e.g., rare-earth permanent magnets, and an outer or peripheral array of magnets 112 surrounding the central array of magnets 111, creating a magnetic racetrack configuration adjacent to the outer circumferential wall of the support structure. Both the inner and outer arrays of magnets are typically mounted on the same side of the pole piece. When the magnet bar assembly is used in conjunction with a sputtering target in a sputtering coating process, the magnetic racetrack configuration causes the formation of a plasma-restricted region, e.g., a plasma racetrack, near the target surface surrounding the magnet bar assembly circumferentially. The magnetic structure 110 may be segmented, for example, including several consecutive segments arranged linearly along the length axis, width axis, or diagonal axis of an elongated support structure. For example, each end and central portion of the magnetic structure may be a segment that facilitates the exchange of ends of different shapes for different target designs, for example, to better fit a dog bone-shaped target. Although shown as a flat structure, the pole pieces may be angled toward their outer rim or curved to better fit the circular cross-sectional shape of the tubular support structure and / or target tube. Alternatively, the radially outward oriented surfaces of the magnets constituting the inner and / or outer arrays of the magnets may have angled or curved surface geometry.

[0068] Actuators 120a to 120d may be located in the same compartment or in different compartments of the support structure, and their respective longitudinal locations are distributed over the length of the support structure 150. Actuators 120a to 120d are preferably electrically driven actuators, for example, electric motors with a linear drive mechanism, or electric motors coupled to a linear drive mechanism, for example, a lead screw. In the control assembly 100 of this embodiment, each actuator comprises, or consists of, an electric motor 121 enclosed by, for example, a motor housing, a gear reduction unit 122 provided, for example, as a gearbox, a gear transmission unit 123, and a linear actuator member 124 (for example, an actuator post or lead screw). The gear transmission unit 123 converts the rotational motion of the output shaft of the gear reduction unit 122 into linear motion of the linear actuator member 124.

[0069] Other types of actuators besides electric motors may be pneumatic or hydraulic actuators. Electric motors as actuators can be energized and controlled through a single wire connection, for example, by using power line modulation. This has the advantage of not requiring bulky battery packs. The available space within the target tube is limited to allow for a compact arrangement for energization. Furthermore, battery packs have a limited cycle life and require periodic replacement. If a production campaign is underway, it will need to be stopped to carry out this replacement.

[0070] In exemplary embodiments of the present invention, the magnetic structure 110 is coupled to a support structure 150 via actuators 120a-d, and the circumferential outer wall of the tubular support structure 150, having end caps 151, 152, forms a protective enclosure for the magnetic structure 110. A connecting piece 126 may be provided on the radially inward oriented surface of the pole piece 113 opposite to the surface of the pole piece supporting the magnet arrays 111, 112, and may be configured to cooperate with the corresponding headpiece 125 of the linear actuator member 124 to fasten the magnetic structure to the actuator, thereby establishing an indirect coupling between the magnetic structure and the support structure. The described method of coupling the magnetic structure and actuator to the elongated support structure ensures that the actuator can act on the magnetic structure to change the position of the magnetic structure at several different locations along the longitudinal axis of the magnetic structure. However, embodiments of the present invention are not limited to this particular type of coupling and can be implemented in many ways.

[0071] In a modification of the above-described embodiment, the pole pieces of the magnetic structure (e.g., soft iron pole pieces) may be separated longitudinally, for example, by cutting along the length of the support structure, resulting in three elongated, for example, equally-width pole piece segments or strips instead of a single one. The central pole piece segment or central strip may then carry the central array of magnet 111 and the end magnets (outermost magnets) of the peripheral array of magnet 112, while the remaining magnets constituting the peripheral array of magnet 112 are placed on the two outer pole piece segments or peripheral strips. The coupling mechanism connecting the three pole piece segments to the support structure (e.g., directly or indirectly via local actuators) may include hinges. Linear motion of local actuators, for example, imparting deformation to the central pole piece segment, can be additionally or selectively converted into variable inclination angles of the peripheral pole pieces and attached magnets. Therefore, the angle between the two legs of a magnetic / plasma racetrack leg can be locally tuned to a smaller angle by rotating the outer pole piece inward and toward each other, thereby decreasing the azimuthal distance between the magnets of the peripheral array attached to the rotating outer pole piece, or it can be adjusted toward a wider angle by tilting the outer pole piece outward and toward each other, thereby increasing the azimuthal distance between the magnets of the peripheral array attached to the rotating outer pole piece.

[0072] Furthermore, the fact that actuators are adapted to locally change the position and / or orientation of the magnetic structure does not preclude the possibility of tuning the magnetic structure as a whole. Overall tuning of the magnetic structure can be achieved via one or more dedicated overall actuators, or preferably by simultaneously driving local actuators to produce an overall change in the position of the magnetic structure (e.g., overall translation along at least one movement axis) and / or an overall change in orientation (e.g., overall rotation around at least one orientation axis).

[0073] Although described in terms of a tubular shape, in different embodiments of the present invention, the support structure may adopt a non-tubular shape. For example, the support structure may include a substantially planar portion as a mounting platform for control units, memory devices, and actuators, and an elongated shaft to which the planar portion can be attached. A protective and insulating sleeve, or a protective and insulating material layer such as paint, can be applied to the mounting components on the support structure, e.g., control units, memory devices, actuators, and magnetic structures coupled to the actuators. In yet another embodiment, the substantially planar mounting platform or plate may be combined with an extruded profile or elongated pipe having a cross-sectional arc segment, e.g., a circular arc segment, to assemble an elongated support structure.

[0074] A control assembly according to an embodiment of the present invention is connectable to an end block of a magnetron sputtering apparatus and includes, for example, connection means for mounting a support structure to at least one end block. Such connection means may include an inner receiving flange or bearing member of the end block cooperating with the end tap of the control assembly. A target may be mounted on the outer support flange of the end block and surround the control assembly circumferentially, and a target mounted on the end block may be attached to the support structure of the control assembly via a countercenter at the opposite end of the target (far from the end block). Furthermore, the control assembly may be connectable to two different end blocks located at each end of the support structure, for example, via end pieces, closing caps, covers or flanges of the support structure, or may be fastened to the support structure.

[0075] Figure 2 is an enlarged view of the mechanical and communication interface 160 of the control assembly 100, which enables connection of the support structure 150 to the end block. The journal of the interface 160 is formed by a shell-shaped end tap or a hollow cylindrical section 20 projecting orthogonally from an inclined region 21 on the outer surface of the end piece 151. The journal may be oriented substantially coaxially with respect to the longitudinal axis of the elongated support structure, for example, the central axis. The shell or cylindrical section 20 includes a slot 22 for aligning the support structure and the magnet bar assembly with respect to the end block, for example, when the journal slides into the bearing element (e.g., bore or bush) of the end block. The shell or cylindrical section houses electrical pins 23 inside, which form part of the electrical connector between the control assembly 100 and the end block. When the control assembly is connected to the end block, the electrical pins are inserted into sockets provided on the end block. Thus, the electrical pins correspond to the male connector component of a plug-and-socket type electrical connector. Nevertheless, female connector components (e.g., sockets) of plug-and-socket type electrical connectors may be provided for the mechanical interface and constitute an alternative embodiment of the present invention. Shielding 25 around the electrical pins 23 may assist in matching the electrical pins, and advantageously, may also include a built-in fluid seal to shield data signals traveling across the interface 160 from ambient coolant fluid, such as water.

[0076] Electrical connectors can be signal connectors in a communication link between an end block and a control assembly, allowing the control unit of the control assembly to communicate with software or hardware modules located within or beyond the end block and exchange data. For this effect, an electrical cable or wire 24 is provided inside the support structure 150 of the control assembly and bridges the distance between the electrical pins 23 and the transceiver module 33 of the control assembly. Additionally or alternatively, electrical connectors can be used as conductors in a power distribution system to transfer power between the end block and the electronic components of the control assembly. For example, actuators of the control unit and / or control assembly may be energized via electrical connectors. Power line communication may be implemented within a power distribution system that includes electrical connectors so that power and data signals can be combined on a single wire / conductor.

[0077] Embodiments of the present invention are not limited to telecommunications links between a control assembly and an end block to which it can be connected. Long-distance communication between the electronic components of the control assembly and, for example, electronic components connected to an end block via a mechanical interface, may be wired or wireless, and, for example, telecommunications signals may be transmitted optically or acoustically as RF signals via capacitive or inductive coupling. Telecommunications links may also be installed between the electronic components of the control assembly and a magnetron sputtering apparatus unit or sensor and / or a coating system including the control assembly. Signal transmitters and / or receivers may be coupled to an elongated support structure alongside the control unit and operably connected to the control unit, while at least one signal transmitter is located at a distance from the control assembly.

[0078] For example, an optical long-range communication link between an end block and a control assembly (e.g., a magnet bar assembly) may comprise an optical signal emitter disposed within or near the end block, combined with an optical fiber cable and optical fiber connector, or an optical receiver within the control assembly. The optical signal may propagate at least partially in a liquid waveguide formed by a coolant, either flowing along a fluid channel inside the support structure or in the space between the outer wall of the support structure and the inner wall of the target tube within the magnetron sputtering apparatus. An optical window may be provided in one or both of the end pieces of the support structure.

[0079] Figure 3 is a detail view of the portion of the control assembly 100 in which the control unit 130 is located. The storage device 140 is mounted near the control unit 130, for example by mounting the storage device and the control unit on the same circuit board 31 or on adjacent circuit boards, and is operably connected to the control unit 130 so that the control unit can access the data stored in the storage device 140. For this effect, electrical wires or signal traces on a printed circuit board may be provided. Driver circuits 127, located in close proximity to each actuator of the assembly, are configured to convert control signals into corresponding drive signals. The drive signals are suitable for driving the electric motors 121 of each actuator in a controlled manner. Thus, each driver circuit 127 functions as a local motor controller. Control signals are generated and output by the control unit 130 and transmitted via interface wires 34 to the respective interface connectors 35 of the driver circuits 127 (for visibility, the actuators in front of the interface wires 34 and interface connectors 35 are not shown in Figure 3). In embodiments of the present invention, the control signals and drive signals are different types of signals. A drive signal, such as a PWM signal, is generated by a driver circuit in response to a control signal, causing an actuator, such as a linear actuator member, to change its current position and / or orientation according to the drive signal. Thus, the drive signal is used to set the new position and / or orientation of the actuator. A feedback loop, such as measuring the current position / orientation of the actuator and comparing it with a target position / orientation to derive a correction signal, may be implemented for this purpose. In contrast to the drive signal, the control signal is simply used to transmit information about the desired new actuator position / orientation to the driver circuit. The control signal may encode the value of the new actuator position / orientation according to a communication protocol or to optimize the transmission of data packages exchanged between components of the same control assembly. Therefore, the control signal is designed to perform tasks specific to the carrier layer, in addition to transmitting control data regarding actuator settings.These tasks may include driver circuit addressing, data encoding, timing of data frame transmission, optimization of transmission over specific interface wires, implementation of specific communication protocols, handshake operations, fault or timeout detection, frame retransmission after fault or timeout detection, and implementation of forward error correction schemes. Separating control and drive by performing these tasks in different units has the advantage of allowing the driver circuit to be designed or provided as a more compact, less complex, and less expensive circuit. Furthermore, the exchange of external data can be managed exclusively and more efficiently by the control unit, which reduces slow data traffic over communication links through mechanical interfaces. In particular, setpoints for actuators are determined or calculated by the control unit according to pre-stored inputs present in a memory device, which also allows for rapid access to corresponding control points for a large number of actuators and magnetic structures. Since this task is performed by the control unit within the magnet bar assembly, there is no need to remotely calculate the control trajectory and transmit it over a communication link. This enables faster tuning of the position and / or orientation of the magnetic structure. As a result, the control assembly can quickly adapt the magnetron's magnetic structure to changes in the sputtering process, for example, enabling online adjustment of the magnet bar in a magnetron sputtering apparatus. Thanks to the online adjustment of the magnetron's magnetic structure, non-planar substrates, such as those curved in one or two dimensions, can be uniformly coated across the entire substrate surface during a continuous coating process, even though the surface distance from the target to the substrate as it moves through the sputter source of the in-line coating equipment is changing. Here, uniform coating refers to applying the coating layer to the surface or surface portion of the substrate material so that the layer properties of the coating layer are uniform across the coated substrate surface or surface portion.The aforementioned layer characteristics include coating layer thickness, optical layer characteristics (e.g., uniform refractive index, reflection coefficient, extinction coefficient, etc. across the coated substrate), electrical layer characteristics (e.g., uniform sheet resistance across the substrate), magnetic layer characteristics (e.g., uniform magnetoresistance or magnetic tunnel resistance across the substrate), mechanical layer characteristics (e.g., uniform roughness, hardness, stress, elasticity, etc. across the substrate), or morphological layer characteristics (e.g., uniform crystal structure, crystal orientation, density, etc. across the substrate).

[0080] External data reaches the input connector 32 of the control unit 130. Here, external data refers to general data, including commands, setpoints, update values, and measurements, which are prepared remotely (e.g., collected, created, ...), i.e., at a certain distance from the control assembly, and transmitted to components of the control assembly via a dedicated communication link. The external data is generated from an external source, such as a trigger unit, sensor unit, hardware or software module, which communicates with components of the control assembly (primarily the control unit) via a dedicated communication link, rather than forming part of the control assembly. Thus, the input connector of the control unit is operably connectable to a trigger unit located away from the control assembly. In this embodiment, the dedicated communication link includes an electrical connector extending through a mechanical interface and a transceiver module 33. In other embodiments of the present invention, the communication link may not be an electrical, e.g., optical or acoustic link, and / or may be implemented in a different way, e.g., supplied through a signal window instead of a mechanical interface.

[0081] The transmitter and / or receiver module 33 is an optional component of the control assembly, not required in all embodiments of the present invention. It may be adapted according to the type of physical signal used for communication, e.g., a transceiver module for electrical signals, an antenna and transmitter / receiver module for radio signals, an optocoupler or photoreceiver module for optical signals, etc. However, it has the advantage of enabling conversion of signal type (e.g., optical to electrical, or vice versa), signal level (e.g., voltage amplitude level), and signal transmission format (e.g., digital or analog transmission format or protocol), depending on the characteristics of the particular communication link and the I / O capabilities of the electronic components inside the control / magnet bar assembly. Data signal conversion by module 33 may be useful when the control unit cannot safely receive or interpret the raw data signal used for transmission over the communication link 160. Furthermore, it may often be beneficial to transmit data only in a predetermined low-frequency band to reduce the risk of erroneous data signals being transmitted over the communication link in the presence of higher-frequency noise, although higher-frequency signals may be used for communication between components of the control assembly that are easily shielded from noise. Noise interference that disrupts data transmission through mechanical interfaces may originate from, but is not limited to, power signals supplied to the sputtering target, arc events, or plasma ring effects. This limits the available bandwidth and speed for external data exchange via the communication link. Therefore, the amount and frequency of external data exchanged and consumed by the control unit should be reduced as much as possible. In conventional magneton systems, transmitting control commands for all actuators via the communication link between the magnet bar assembly and its connected end blocks, and regulating the actuators to new desired positions, can take several seconds. This is too long compared to the time it takes for the substrate to pass through the sputtering source. Furthermore, variable setpoints are often required during this exposure time.

[0082] The storage device preferably includes persistent memory, such as integrated circuit flash memory or other types of non-volatile memory, such that data stored therein is not lost when the storage device is not powered. This minimizes energy consumption and latency caused by rearranging / rewriting data stored in the storage device before it becomes accessible to the control unit during the sputtering process. Alternatively, non-persistent memory, such as volatile memory, can be used as the storage device, and the relevant data can be loaded into the storage device at the start of a particular production campaign or uploaded when the substrate type changes. The data stored in the storage device relates to control inputs for the control unit, i.e., inputs required by the control unit to determine the control trajectory for each actuator and to convert the control trajectory into a control signal sequence that can be verified and interpreted by the driver circuit for each actuator. Additionally, one or more sputtering process parameters, sputtering recipes, magnetron sputtering apparatus configuration parameters, and / or substrate surface-related information can be persistently stored in the storage device and accessed by the control unit to compute setpoint list conversions. It is advantageous that only a limited number of approximate setpoint lists are stored in the memory device, which are then adapted, converted, or manipulated by the control unit to obtain a number of improved setpoint lists, each more accurate considering the specific sputtering process, magnetron equipment configuration, or substrate surface characteristics.

[0083] In embodiments of the present invention, the control assembly includes at least one control unit, which is • Load control inputs from at least one memory device, Based on the control input, determine the control trajectory for at least one actuator, • To generate a control signal sequence for at least one actuator according to the control trajectory, The system is configured to synchronize the transmission of control signal sequences to the driver circuit of at least one actuator with a trigger signal from a remote trigger unit outside the control assembly.

[0084] The control input includes one or more setpoints for at least one actuator, or alternatively, data that enables the calculation of one or more setpoints for at least one actuator. Its simplest form includes a list of several positions on the actuator that need to be restricted, although there is at least one. Here, the restricted positions may be identical to or derived from setpoints. For example, the control unit may be configured to perform a calibration step on the loaded setpoint when determining the restricted positions of the control trajectory. This allows for correction of actuator offsets and / or compensation for drift, sensitivity changes, or actuator mismatches caused by aging, temperature, wear, etc. The values ​​required for the calibration step may also be stored in a memory device. Preferably, the setpoints for actuators are stored as a list or table on the memory device so that the setpoints for a particular actuator can be easily retrieved. The list or table header may include information that enables the identification of each actuator and its corresponding setpoint, as well as optionally any available inputs for calibration.

[0085] Many different lists or tables can be stored on the memory device, each containing actuator setpoints for specific control or tuning scenarios of the magnetic structure. Tuning scenarios can be predefined or user-defined scenarios that can be written to the memory device at various points in time, such as immediately after manufacturing, during the construction of the control assembly, or via a software client or REST-API installed on the control unit. Each scenario may be characterized by a set of parameters, including parameters such as partial gas pressure, composition and / or distribution of the plasma and reaction gas mixture, sputter mode (DC / AC / RF), parameters related to the target material, target thickness and target lifetime (e.g., kWh lifetime), parameters related to the sputter geometry (e.g., shield geometry and aperture, minimum target to substrate distance, target length, anode position), and parameters related to the substrate (substrate material, substrate surface dimensions, substrate curvature). A unique scenario identifier can be assigned or calculated from each parameter combination characterizing the scenario. The control unit may use the unique scenario identifier to determine the list or table of setpoints to load at runtime. In some embodiments of the present invention, the scenario identifier may be a user input or system input of a coater device transmitted via a communication link to a control unit. A software client or application programming interface (API) installed on the control unit may set a pointer to a memory location in a storage device according to the new scenario identifier. Alternatively, the scenario identifier may be communicated as part of a trigger signal dispatched by an external trigger unit to synchronize the transmission of control signals from the control unit to the actuator driver circuit.

[0086] Furthermore, it is possible to add new scenarios or modify existing ones. The former is useful during the development of a new sputter coating process or production campaign, while the latter is useful for updating calibration routines for actuators or correcting slow changes in magnetic field configuration at the target surface due to target erosion, sputter source contamination, etc. Scenarios can also be swapped or dynamically updated during execution, which greatly assists operators in tuning the process and layer thickness uniformity profiles when changing products (different layer stacks or different substrates) at the start of a production campaign or during a production campaign. This significantly reduces the time required to set up in-line coating equipment before starting a new production campaign or when changing products during a production campaign, and avoids the time spent on repeated venting steps in the vacuum deposition chamber.

[0087] For actuators with several degrees of freedom, e.g., different rotation and / or translation axes, each list entry defines a desired value for each control axis of the actuator. A flat substrate coated with a layer of uniform thickness may require only a single entry to the list of restricted positions for each actuator. This list entry generally depends on the actuator's location along the length axis of the elongated support structure, corresponding to the actuator's location along the length axis of the magnetic structure. It may depend on additional factors such as target lifetime, target material, and plasma composition. Conversely, non-flat substrates, e.g., curved or non-constant height profiles, typically require the definition of numerous list entries. For example, target positions may be defined for each vertex, edge, or simplex / polytope of a mesh overlay on the substrate surface, resulting in a 2D array of target positions, and a list of restricted positions for each actuator may be obtained as a selection of individual rows in the 2D array. Nevertheless, the control unit may be configured to insert additional restricted positions when determining the control trajectory, for example, through interpolation between initial restricted positions. This can help the driver circuit move the actuator in a smoother and less robust manner, avoid overshoot or ringing, and prevent extreme acceleration.

[0088] In some embodiments of the present invention, a control unit may be configured to load setpoints for actuators of a control assembly from one or more memory locations in a storage device and to apply transformations to the loaded setpoints. A transformation function may be applied point-by-point to each loaded setpoint. Preferably, a simple transformation function, such as a linear function, is evaluated by the control unit because it is easy to compute and does not require much processing power. The applied transformation function may be stored in the storage device as part of executable code or a runtime library that can be accessed by the control unit or communicated to the control unit via a communication link. Any transformation function applied to a setpoint may accept further parameters as input. This allows the transformation function to consider additional process or equipment parameters, for example, the transformation function may represent a heuristic or pre-measured relationship between the loaded setpoint and the transformed setpoint under a given change in process or equipment parameters.

[0089] For example, a loaded setpoint for an actuator may be associated with a specific process, such as a tungsten sputtering process, while a control unit receives external data through a trigger signal that defines a different process, such as an aluminum sputtering process. The control unit can then apply a scaling transformation to the loaded setpoint, where the scaling factor serves as a further input parameter describing the quantitative change in the setpoint when aluminum is replaced with tungsten as the target material to be sputtered. In this specific case, for example, the expected deposition material distribution can vary significantly depending on the operating pressure of the sputtering process. At relatively high operating pressures, sputtered material particles may undergo many interactions and collisions with the working gas. The scattering of sputtered particles may differ if the working gas contains, for example, argon, nitrogen, or oxygen molecules. Aluminum, being a fairly small and light atom, can deviate significantly from its migration path after gas interactions, while heavier tungsten atoms will be far less affected in their trajectory by similar gas interactions.

[0090] Alternatively or additionally, the loaded setpoint for an actuator may be associated with a specific lifetime of the target material being sputtered, e.g., zero lifetime of the target when it is first mounted, while the control unit receives external data, e.g., a specific amount of kWh of the sputter target currently in use and already eroded, through trigger signals that define different lifetimes of the sputter target, for example. The control unit may then apply alternative or additional scaling transformations to the loaded or already transformed setpoint, where the scaling factor serves as a further input parameter describing the quantitative change of the setpoint when a sputter target with a non-zero lifetime is used. Embodiments of the present invention are not limited to the preceding transformations or simple scaling functions, and instead may use different input parameters and / or more complex functional relationships. This includes the use of transformation tables (e.g., lookup tables) or the application of transformation functions as part of a feedback control algorithm that can be performed by the control unit. Transforming a loaded setpoint is equivalent to adjusting the control trajectory for an actuator in embodiments of the present invention where the loaded setpoint is directly used as the regulated position. In other embodiments of the present invention, the loaded setpoint may be modified to a restricted position after being loaded by the control unit, for example, when performing calibration or feedback control, to enable the generation of a control trajectory. In these cases, the modification can similarly be applied to the restricted position of the generated control trajectory to obtain a tuned control trajectory.

[0091] In some embodiments of the present invention, control inputs loaded from a storage device into a control unit are different from the actuator setpoints, but enable their calculation. In such embodiments, the control unit is additionally configured to derive setpoints for the actuators of the control assembly based on the accessed control inputs. While computationally more intensive, the calculation of setpoints by the control unit, or another processing unit of the control assembly managed through the control unit, improves the flexibility and ease of use for the end user when preparing and writing or rewriting the types of control inputs to the storage device so that they can be accessed by the control unit. One embodiment is the specification of a local sputtering rate at each point on a calculation grid overlaying a curved or non-curved substrate surface to be coated uniformly or according to a predetermined coating profile. As the substrate passes through the sputtering source, the local sputtering rates need to be dynamically adapted, which is fully or at least partially solved by the corresponding adaptation of the regulated positions of the actuators along the support structure of the control assembly. The control unit, or a further processing unit of the control assembly managed through the control unit, may then calculate the actuator setpoint as a function of a predetermined local sputtering rate at each grid point. Additional information regarding the current sputtering process and equipment may be accessed on a storage device or received as external data communicated to the control unit via a communication link, if required to perform or improve setpoint calculations. Another embodiment is the specification of the substrate height at each point on a calculation grid overlaying the curved or non-curved substrate surface to be coated uniformly or according to a predetermined coating profile. As the substrate passes through the sputtering source, the distance between the sputtering source and the substrate surface to be coated changes dynamically, and the local sputtering rate must change accordingly. This can be solved entirely or at least partially by corresponding adaptation of the restricted position of the actuator along the support structure of the control assembly.A control unit, or a further processing unit of a control assembly managed through a control unit, may then calculate actuator setpoints as a function of a predetermined substrate surface height at each grid point. The substrate surface heights at various points on the calculation grid may be taken from or extracted from a CAD profile or a measured surface scan (e.g., optical or mechanical surface scan), which can be written to a storage device. Advantageously, the control unit or processing unit managed by it may calculate the setpoints once for each new sputtering process, product change (e.g., different coating layer properties), and / or substrate change (e.g., different surface profile), store the calculated setpoints in a storage device so that they can be easily accessed by the control unit when sputter coating similar substrates with similar sputtering processes. Furthermore, the calculation of setpoints for new sputtering processes, product changes, and / or substrate changes may be performed in advance while the current process, product, and / or substrate type are still in operation. The calculated setpoints can be exported so that an operator or process engineer is permanently informed of the current and future configurations of the actuators in the control assembly. This allows for the smooth and rapid adaptation of the magnetron sputtering equipment to the modified process, product, and / or substrate without interrupting an ongoing production campaign. Therefore, downtime for the magnetron sputtering equipment and associated coating lines can be reduced, saving operational costs. Similarly, the time required to develop a new sputtering coating process or to tune the magnetron sputtering equipment and associated coating lines at the start of a production campaign can be significantly reduced.

[0092] In certain embodiments of the present invention, the control unit may be equipped with additional local processing capabilities, for example, the control unit may include a coprocessor as a subunit. This allows the control unit to transfer computational tasks to the coprocessor, where they can be performed more efficiently. Computational tasks may include applying conversion functions to actuator setpoints or regulated positions, or online calculation of setpoints based on information loaded from a storage device, such as a substrate height profile or a CAD file.

[0093] The controlled positions of actuators appearing on the control trajectory are converted into a corresponding sequence of control signals, for example, by encoding them and placing them in a data frame of a predetermined communication protocol. This conversion may be performed sequentially; for example, each new control signal in the sequence is generated when a preceding control signal of the same sequence is transmitted, or they are all generated in a single step before the first control signal is transmitted. Each control signal sequence addresses a corresponding driver circuit, and the individual control signals in this sequence are dispatched sequentially.

[0094] The duration of the time interval between dispatch events of two consecutive control signals in a sequence can be determined by the control unit based on the substrate transport profile, which can be stored in a memory device and accessed by the control unit, or communicated to the control unit as external data via a communication link. The substrate transport profile is a pre-calculated list or table that defines the time interval between a series of control signals for a given substrate movement trajectory through a sputter source and a given mesh / grid on the substrate surface to which reference points on the substrate surface are assigned, defining the target position of the actuator. Alternatively, the control unit can access a constant value for the time interval between dispatch events of two consecutive control signals in a sequence from a memory location in a memory device, or such a constant value can be transmitted to the control unit via a communication link and, for example, included in a trigger signal detected by the control unit on its trigger input signal connector.

[0095] A control unit according to an embodiment of the present invention is configured to synchronize the transmission of a control signal sequence with a trigger signal at its input connector. The trigger signal is issued by an external trigger unit located at a distance from the control assembly and communicated to the control unit of the control assembly via a communication link through a mechanical interface or via a separate communication link. In practice, the trigger signal will be directly or indirectly related to the position of the substrate to be coated relative to a magnetic structure whose position / orientation is adjusted by the actuator of the control assembly. This allows the control unit to determine the start time of the transmission of the control signals in each control signal sequence. In some embodiments of the present invention, the control unit may start transmitting at least one control signal sequence, for example, the first control signal of all sequences, immediately after receiving the trigger signal at its input connector. In other embodiments of the present invention, the control unit may calculate the respective start time or delay for transmitting the first control signal of each sequence based on the trigger signal received at its input connector. This calculation of the start time or delay may use the time resulting from the trigger signal detection event at the input connector of the control unit, additional information about the originating trigger unit, such as an identifier that enables extraction of the location of the trigger unit in the coater equipment relative to the magnetic structure or an identifier that enables access to the location of the trigger unit in a table stored in a storage device which is part of the trigger signal, and substrate transport speed information included in the trigger signal or accessible on the storage device.

[0096] An external trigger unit can be a sensor unit in an in-line coating system. An exemplary sensor unit is a substrate position sensor that detects a moving substrate at a location along a substrate trajectory through a vacuum deposition chamber. Such a position sensor may be mounted along a conveyor system that transports the substrate through the chamber and may be configured to emit a trigger pulse when a substrate is detected at a sensed location. The trigger pulse can then be transmitted to a control unit to synchronize the timing of control signals in a sequence with the substrate position.

[0097] In embodiments of the present invention, these multiple sensor units may be mounted along a conveyor system, thereby enabling detection of the substrate at different sensed locations while moving through the deposition chamber and passing through the sputter source. Thus, multiple corresponding trigger signals can be obtained and transmitted to a control unit to improve and / or maintain good synchronization between the timing of the transmitted control signals and the position of the substrate relative to the magnetic structure whose position / orientation is controlled.

[0098] In embodiments of the present invention, the trigger signal may have different levels of complexity. For example, the trigger signal may correspond to at least one interrupt request (e.g., a single pulse) or may include a signal sequence having data in a predetermined format (e.g., including board type, travel speed, or, for example, board position).

[0099] In yet another embodiment of the present invention, the trigger unit may be part of a coater or substrate transport system, for example, a movable part whose movement correlates to the position of the substrate within the coating equipment. For example, the trigger unit may correspond to an inlet valve that separates a vacuum deposition chamber, including a control assembly, from a load lock section along the coating line or another deposition chamber. When the gate reaches its open state, a trigger signal may be released and transmitted to the control unit. The time required for a substrate of a given size to pass through the gate and move to a position below the sputter source, including the control assembly, may be stored in a memory device and made accessible to the control unit, or may be encoded in the trigger signal itself. Similarly, the trigger signal may correspond to a homing position signal that is generated as soon as an outlet valve opens, causing the coated substrate to leave the deposition chamber. Embodiments of the present invention are not limited to the trigger unit described above, and other components of a sputtering magnetron apparatus may function as a trigger unit.

[0100] In embodiments of the present invention in which a control unit determines the interval between subsequent control signals, a timing subunit of the control unit or a timing unit of the control assembly, such as an incremental counter, may provide a timing signal as a reference for comparison when determining the moment when the interval between subsequent control signals has elapsed. The timing subunit of the control unit or the timing unit of the control assembly may include a clock signal generator or oscillator. Alternatively, a subsequent trigger pulse may be used to time the transmission event of the subsequent control signal.

[0101] In embodiments of the present invention, two or more storage devices and / or two or more control units may constitute a control assembly. For example, different setpoint lists or tables may be stored in different storage devices that form a distributed shared memory with respect to one or more control units. The different setpoint lists may be associated with different process parameters that affect the sputter coating process. In certain embodiments, the control units can therefore respond quickly to changes in sputter process conditions (e.g., changes in partial gas pressure, changes in power supply to the target, changes in target or substrate surface temperature, etc.) by switching from a first list of setpoints stored in a first storage device to a second list of setpoints stored in a second storage device. Alternatively, if the storage devices have sufficient memory size, the different setpoint lists may be stored and indexed as separate tables within the same storage device.

[0102] According to some embodiments of the present invention, a control assembly comprises a plurality of actuators and a plurality of corresponding control units. Each control unit may access its own memory device. This enables parallel and independent control of a large number of actuators extending over the length of the control / magnet bar assembly without concerns about memory congestion and without implementing complex time-multiplexed data processing and signaling schemes.

[0103] In another embodiment, the present invention relates to a magnetron sputtering apparatus comprising a control assembly of the first embodiment, a magnetic structure attached to a support structure of the control assembly, a sputtering target substantially coaxially mounted on the support structure, and an end block system connected to the assembly and the sputtering target. The magnetron sputtering apparatus may further comprise at least one trigger unit located outside the control assembly and distal to the control assembly. The at least one trigger unit may be a substrate position sensor. The magnetron sputtering apparatus is suitable for sputter coating of non-planar substrates by a coating layer having uniform layer characteristics across the substrate surface to be coated. The magnetron sputtering apparatus is suitable for sputter coating of a non-uniform coating layer on a flat or curved substrate surface, the non-uniform coating layer being controllable and specified by a coating layer profile.

[0104] In this embodiment of the present invention, the sputter target is a rotating target. It is generally formed as an elongated hollow rotating body and can have inner and outer surfaces of different shapes extending along an elongated axis. In some embodiments of the present invention, the sputter target has a cylindrical or substantially cylindrical rotating outer surface, thus producing a tubular sputter target. For example, the rotating inner and rotating outer surfaces are separated by a fixed radial distance perpendicular to the axis of rotation, resulting in a hollow cylinder with fixed inner and outer diameters. Another embodiment has a cylindrical inner surface having a fixed inner diameter (i.e., produced by rotating a straight line parallel to the axis of rotation) and a rotating outer surface of the sputter target having an outer diameter of various sizes, for example, constant in the central portion of the sputter target but widening toward or at the ends of the sputter target. A rotating outer surface in the shape of a dog bone or dumbbell is an example of an outer surface having various outer diameters. Advantageously, such flared edges of a sputtering target partially or completely offset the increased target erosion (end groove formation) primarily caused by turnaround sections of the plasma racetrack adjacent to these edges under sputtering conditions (changes in plasma density and longer residence time of the target material under plasma impact). The flared sections of the target may be the result of a thicker sputtering material stock in these sections applied to a cylindrical outer diameter backing tube, or the result of a molded backing tube, e.g., a backing tube including a non-consumable collar welded to the section where flaring is desired, e.g., the end sections of an otherwise straight backing tube. The thickness of the sputtering material may be uniform on a molded backing tube or may have a variable thickness (e.g., a constant outer diameter).

[0105] In yet another aspect, the present invention relates to an inline vacuum sputtering coating apparatus comprising: a magnetron sputtering apparatus according to a prior aspect of the present invention; a transport system for moving a substrate through the magnetron sputtering apparatus; and at least one trigger unit located outside the control assembly of the magnetron sputtering apparatus and disposed distal to the control assembly of the magnetron sputtering apparatus.

[0106] Typically, an in-line coating apparatus comprises a vacuum chamber having an inlet slit and an outlet slit, through which the substrate to be coated enters and exits the respective deposition chambers. The inlet and outlet slits may be equipped with gate valves connecting the deposition chambers to load locks, purge chambers, or further deposition chambers along the coating line of the sputtering apparatus. Conveying means, such as rollers or conveyor belts, transport the substrate to be coated through the deposition chambers and through the sputtering source. During transport, the substrate to be coated may be fastened to a substrate holder or frame. The in-line coater apparatus may be configured as a horizontal or vertical coater. In a horizontal design, the substrate surface to be coated is oriented parallel to the floor and perpendicular to the direction of gravity, while in a vertical design, the substrate surface to be coated is oriented substantially perpendicular to the floor. The sputtering source typically comprises end blocks mounted on the walls of the vacuum chamber (e.g., side mounting or drop-in sections) and interfaces with external and non-vacuum components of the sputtering apparatus. In particular, the interface provides communication channels for coolant feedthrough, electrical feedthrough, and optionally for drive means systems (primarily for target rotation, and possibly for tilting the magnet structure), sensors, trigger and control data, and others. A transmission structure for mechanical movement that independently transmits the driving motion (e.g., driving force, torque) of external drive means to the target support member of the magnetron sputtering apparatus may also be disposed within the end block and partially within the interface. Coolant (typically water) is generally required to remove heat from the target, e.g., tubular ones, and the internal components of the magnetron assembly, which is generated during sputtering, but power needs to be supplied to the target.The end block also provides electrical isolation means to protect sensitive electronics and accessible components of the magnetron housing from high-power electrical signals applied to the target during sputtering, as well as seal cassettes for liquid and vacuum seals of the coolant circuit, which prevent leakage of liquids and gases, release of gases into the deposition chamber, and contamination of the deposition chamber.

[0107] At least one trigger unit may be a sensor unit comprising one or more position sensors for detecting a substrate at a predetermined location along the transport system, or a detector unit for detecting the position or open state of a vacuum valve, such as an inlet or outlet valve of the deposition chamber of an inline sputter coating apparatus to which a control assembly is mounted. At least one trigger unit is configured to transmit a trigger signal to at least one control unit when an individual substrate is detected at a predetermined location along the transport system. This type of inline vacuum sputter coating apparatus is suitable for generating repeatable and reproducible coating profiles on moving substrates.

[0108] Figure 4 is a cross-sectional view of a vacuum deposition chamber 400 having a magnetron sputtering apparatus as a component of an inline vacuum sputtering coating apparatus according to an embodiment of the present invention. The magnetron sputtering apparatus comprises a control assembly 100 according to a first aspect of the present invention, a magnetic structure 111 attached to a support structure 150 of the control assembly 100, a sputtering target 436 substantially coaxially mounted on the support structure 150, and an end block system 438 connected to the distal end of the control assembly 100 and the sputtering target 436. The proximal ends of the control assembly and the sputtering target may float freely within the deposition chamber or may be connected to another end block.

[0109] The sputter target 436 is rotatably supported on an end block system 438, for example, a rotatable mounting flange on which the sputter target can be clamped, and has a rotation axis "R" that is substantially coaxial with the longitudinal axis of the control assembly, for example, the longitudinal axis of the support structure 150. In other embodiments of the present invention, the rotation axes of the first and second support members may be parallel to each other but may be offset. Furthermore, the sputter target 436 is rotatable relative to the control assembly 100, in particular, with respect to a magnetic structure 111 coupled to the control assembly. The control unit 130 of the control assembly is coupled to the inner wall of the support structure 150 and operably connected to a storage device (not shown). Although shown as a hollow cylindrical tube, the support structure may include a component or surface portion having a substantially planar mounting surface, for example, a hollow support tube having a semicircular cross-section. Another exemplary support structure defining a reference plane includes a bent sheet metal, an extruded profile, or a combination of both.

[0110] The end block 438 is mounted on the wall of the vacuum chamber 431, and the drive means (not shown) for the target support member, e.g., a motor belt or motor gear system or a direct drive system, may be compactly arranged inside the end block 238 or provided in a drive box mounted on the wall of the deposition chamber. In the latter case, a mechanical motion transmission structure or component is provided that appropriately transmits the generated drive motion (e.g., drive force, torque), extending through the interface of the end block, which may also include coolant and power signal feedthroughs. Alternatively, the coolant, electrical feedthrough, and / or drive means for the target support member are arranged on a second end block on the opposite side. The mechanical motion transmission structure may include a drive shaft or spindle on which a flange or disk is mounted as the target support member. Alternatively, the ends of the drive shaft or spindle may be adapted to directly receive and support the target.

[0111] The magnetic structure 111 is typically formed by opposite magnetic poles positioned to induce a magnetic field in front of the target surface. In a longitudinal magnetron system, the central portion may consist of three rows of magnets, e.g., three magnet arrays or magnet tracks. The magnets in the central row have associated magnetic poles of a first magnetic pole near the surrounding target 436, and the two peripheral or side row magnets have associated magnetic poles of a second magnetic pole opposite to the first magnetic pole near the surrounding target 436. The magnets in the central and / or peripheral rows may have profiled top shapes or may be slightly inclined relative to each other so that they better fit the circular inner surface of the target 436. A protective sleeve or housing (not shown) may be positioned circumferentially around the magnetic structure 111, between the magnet rows of the magnetic structure and the target, to prevent corrosion of the magnetic structure by a cooling fluid, e.g., water. The plasma racetrack or plasma tunnel 441 is induced by the magnetic structure 111 under the sputtering conditions of the magnetron sputtering apparatus, i.e., in conjunction with the power signal supplied to the mounted sputtering target 436.

[0112] The magnetic structure 111 is coupled to the support structure 150 via a corresponding actuator 120 to complete the magnet bar assembly. The actuator 120 may directly contact the magnetic structure or a segment of the magnetic structure, enabling translation of the magnet along the radial direction perpendicular to the rotation axis "R", and optionally also enabling rotation of the magnet about an axis parallel to the rotation axis "R" and / or an axis perpendicular to the rotation axis "R". Alternatively, the actuator may be connected to the back of an elongated pole piece at different axial tuning positions, with the front of the same pole piece serving as a mounting surface for the radially inward oriented end faces of magnets arranged along different rows of the magnetic structure. The translational and / or rotational displacements of each actuator locally impart bending or torsional forces to the pole piece, resulting in desired adjustments to the position and / or orientation of the magnetic structure. The pole piece may be segmented or cut along, across, or obliquely along its length to facilitate translational and / or rotational displacements in the desired direction, while reducing the required applied forces to the magnetic structure.

[0113] The substrates 435 to be coated enter and exit the deposition chamber 431 through corresponding slits 432, 433. A conveyor belt 434 transports each substrate 435 across the chamber 431 and through the sputtering source. As shown, the substrates 435 may have a height profile, an inclined surface, or a curved surface to be coated in the direction of substrate transport "X", which results in a minimum varying distance between the target 436 and the point on the substrate surface to be coated. In addition, the substrate surface may have a height profile or surface curvature in the direction of axis "R". To obtain a uniform coating thickness across the substrate surface to be coated, the sputter flux reaching the substrate surface must be dynamically modulated as a function of the substrate position relative to the sputter target. The sputter flux may also vary along the direction of a common rotation axis "R" to account for curved and / or profiled substrate surfaces. More generally, the desired material flux can be determined with respect to each point on the substrate surface to be coated, or with respect to each cell of the mesh generated for a substrate surface containing multiple cells. Preferably, the exact substrate surface to be coated is known in advance and determined, for example, through distance or surface scan measurements (e.g., optical ranging or time-of-flight) performed outside or inside the vacuum chamber (e.g., within the load lock section), or extracted from a CAD file.

[0114] As described above, the actuator setpoints can be stored in a memory device as list or table entries, or they can be derived by the control unit from a previously acquired surface scan or CAD file. During operation of the apparatus, the control unit determines the control trajectory for each actuator based on the setpoints, which are accessed from the memory device or calculated from substrate surface-related information stored in the memory device. The control trajectory defines a sequence of restricted positions for each actuator as different surface portions of the substrate (e.g., cells or points of a grid / mesh overlapping the substrate surface) pass under the sputter source. The control unit transmits control signals associated with the control trajectory in synchronization with the substrate movement across the deposition chamber. Thus, the driver circuit can correctly move each actuator to the desired restricted position corresponding to the surface portion currently located directly beneath the sputter target (e.g., cells or points of a grid / mesh overlapping the substrate surface). Here, being located directly beneath the sputter target means the intersection of the sputter target material flux vector and the substrate surface.

[0115] The actual position adopted by the actuator, driven according to the transmitted control signal, closely follows, and ideally matches, the regulated position along the control trajectory determined by the control unit. Advantageously, sensor information, e.g., information related to the substrate position in the deposition chamber, process parameters such as partial gas pressure, target temperature, power supplied to the target, and magnetic field strength along the plasma racetrack, are communicated to the control unit to detect, for example, closed-loop, feedback control, potential malfunctions and / or critical operating conditions of the sputtering apparatus 400. Furthermore, measurement tools that measure the coating performance inside or outside the coating equipment (e.g., optical measurements such as spectral transmittance and / or reflectance data) can provide mapping data of layer performance across the substrate and can be used to implement feedback control through the control unit. The feedback control loop is performed by the control unit, which receives additional sensor data as feedback input data and readjusts or updates the control trajectory for the actuator quasi-instantaneously. The regulated position for the actuator can be corrected based on a comparison between the desired actuator position and the deviation detected in the received sensor data. Alternatively or additionally, the control unit may transmit control signals to the conveyor 434 to correct the position and / or transport speed of the substrate. Deviations from the desired value of the regulated position may be caused by irregularities in the movement of the substrate during transport, irregularities in the target erosion profile, small variations in the surface shape of the substrate between samples, etc.

[0116] The control unit achieves synchronization of transmitted control signals with the substrate position relative to the control assembly and sputter target through the detection of one or more trigger signals at its input connector. The trigger signals transmit substrate position information or in-process events related to the specific position of the substrate in the deposition chamber to the control unit, thereby enabling the control unit to precisely time each control signal transmission event. Trigger signals that can be communicated to the control unit 130 for the purpose of achieving synchronization include, respectively, event-driven data such as a substrate 435 entering or exiting the chamber 431 through an inlet slit 432 or an exit slit 433, and / or substrate position data detected by position sensors 440a-c arranged along the conveyor 434.

[0117] In the modified magnetron sputtering apparatus described, multiple similar sputtering targets and magnet bar assemblies, for example, at least two similar sputtering sources, are mounted along the coating line within the same deposition chamber. This has the additional advantage of reducing the amount of material lost by sputtering on the shield. Instead, multiple sputtering sources sputter each other and accept the target material from one another. The control unit for each sputtering source can be programmed to synchronize the transmission of control signals with the movement of the substrate through the deposition chamber. Furthermore, measurements may be taken after the coating process, behind the coating zone, to help understand the deposited material profile (width and length) across the substrate. The collected measurement data can then be used to achieve further fine-tuning of the sputtered material flux on or near the substrate surface by adjusting one or more of the following: changing control parameters in a control loop performed on the control unit, changing the shield opening, or adjusting the position and / or orientation of the magnetic assembly (globally and / or locally) via a controlled trajectory for the actuator.

[0118] The present invention also relates to the use of a magnetron sputtering apparatus according to an embodiment of a second aspect in a process of sputter coating a moving substrate having a non-planar surface to be coated. Here, an exemplary method 500 for sputter coating a curved substrate is described with reference to Figure 5. Typically, the sputtering target is rotated about its axis of rotation during the sputtering process.

[0119] The sputter coating process 500 includes step 501 of storing control inputs in a storage device disposed inside the magnet bar assembly of the magnetron sputtering apparatus. The control inputs include set points for at least one actuator of the magnet bar assembly, or data necessary for calculating set points for at least one actuator of the magnet bar assembly. In the simplest configuration of the substrate and sputter coating process, this may be a single set point or homing position. The control inputs may be stored on the storage device at different moments in time, for example, before the substrate is placed in the deposition chamber of the magnetron sputtering apparatus, or even during the movement of the substrate, following the manufacture of the storage device, during or following the assembly of the magnet bar assembly including the storage device. For example, as part of a feedback control loop, or when changing the sputtering process, modifying the configuration or settings of the sputtering equipment, changing the product, and / or changing the substrate shape or material, the control inputs may be periodically updated or replaced. The control data, e.g., actuator set points, may be organized into lists or tables. These lists or tables may be associated with a unique identifier that can be used by the control unit to access a particular list or table. Lists or tables with different identifiers may be generated and stored for different combinations of sputtering equipment parameters, sputtering process parameters, and substrate parameters or types. For example, a unique identifier may be assigned to a table of combinations of sputtering target material, sputtering target lifetime, and minimum distance from target to substrate. Parameter combinations may be included in metadata or as headers to tables containing pre-calculated actuator setpoint entries for these parameter combinations.

[0120] The sputter coating process further includes step 502 of loading control inputs from at least one storage device into a control unit of the magnet bar assembly. The control inputs may be loaded serially or in parallel and may be accessed from different locations within the same memory module or different memory modules of the storage device. The storage device may be a distributed memory.

[0121] Furthermore, the method includes step 503 of determining a control trajectory for at least one actuator of the magnet bar assembly based on the loaded control input. Determining a control trajectory for an actuator may include one or more of the following: obtaining a list of regulated positions by copying the loaded setpoints; obtaining additional setpoints by interpolation between the loaded setpoints; and performing calibration operations on the setpoints. In alternative embodiments of the present invention, the control input may relate to a local sputtering rate calculated for each point of a grid overlapping the substrate surface to be coated, or to the height of the substrate surface at each point of a grid overlapping the substrate surface to be coated. The control input may represent other data relating to the substrate topography or the characteristics of the layer to be coated on the substrate surface.

[0122] A control signal sequence for at least one actuator is generated in step 504 according to the determined control trajectory. This step may include encoding the restricted position of the control trajectory for transmission over a communication link inside the magnet bar assembly, and transmitter-side error coding may be performed. The control data to be transmitted may also be prepared according to the transport protocol between the control unit and the actuator's driver circuit. The control data may be placed within a frame, and driver circuit address data may also be included in the frame. The examples given above for this step are not exhaustive.

[0123] The method further includes step 505, which involves receiving an external trigger signal from a trigger unit located distal to the magnet bar assembly, such as a substrate position sensor unit or the output of a substrate transport system, while loading a curved substrate to be coated into a deposition chamber or transporting the substrate through a sputter source; and step 506, which involves synchronizing the transmission of a control signal sequence to the driver circuit of at least one actuator with a trigger signal from the remote trigger unit, i.e., a trigger signal from outside the magnet bar assembly. This step may include extracting the substrate position from the trigger signal and calculating the start time or delay of the transmission of the first control signal among each control signal sequence by combining the extracted substrate position with substrate movement data, such as the substrate speed. An internal timer or counter of the control unit may be reset or programmed accordingly. The substrate movement data may also be extracted from the trigger signal, or accessed from a storage device as external data via a communication link, or communicated to the control unit. Timing information for the transmission of subsequent control signals among each control signal sequence may also be derived and / or improved by the control unit based on the trigger signal or further trigger signals. During transport, the substrates are typically mounted on a carrier or frame of a horizontal or substantially vertical transport system, such as a roller-type or belt-type conveyor system. Preferably, curved substrates are oriented relative to a magnetic bar assembly so that the axis of curvature of the curved substrate is maintained during transport.

[0124] The driver circuit of at least one actuator receives the control signals transmitted in step 507 and converts each (decoded) control signal into a corresponding drive signal, e.g., a PWM signal, thereby moving / rotating the actuator to a new position / rotation angle. This locally adjusts the position and / or orientation of the magnetic structure of the magnet bar assembly.

[0125] The actual position of the actuator after regulation by the driver circuit may be measured in step 508. This measurement may provide feedback information to a control unit that can execute the control loop. The feedback information is compared with the desired regulated position of the control trajectory, and any possible deviations are detected by the control unit. The control unit, or even the logic within the driver circuit, may then readjust or transform the regulated position of the control trajectory based on the received feedback information. Alternatively or additionally, the feedback information may also arise from substrate measurements behind the coating zone, for example, measurements related to the properties of the coated layer.

[0126] Here, an exemplary method 600 for updating or adjusting the control trajectory for a control assembly actuator will be described with reference to Figure 6.

[0127] In the first step 601, the control unit listens for and waits for interrupt signals that transmit information about parameter changes. Receipt of an interrupt signal may interrupt the control unit's generation of control signals or the loading of new actuator setpoints from a memory device. The current calculation of the control trajectory for the control assembly actuator may be aborted. Interrupt signals may originate from an external trigger unit, a substrate transport system, measuring equipment, or a sensor unit located outside the control assembly. Sensors within the control assembly may also trigger such interrupt signals, for example, a temperature sensor or magnetic field sensor sensing a corresponding variable at or near the target surface. The parameter changes mentioned above correspond to changes in process variables, changes in substrate characteristics or type, and / or equipment settings that affect the required sputter flux and therefore require local adjustments to the position and / or orientation of the magnetic structure. Parameter changes that trigger an interrupt signal may include, among other things, the possibility of a new production campaign being started with a different target material, the possibility of detecting a change in operating gas pressure during a running production campaign, the possibility of detecting a deviation in the topography or material properties of the initial or coated substrate during the execution of a production campaign, a detected change in substrate dimensions or orientation, or a parameter change initiated in response to user input. The user may also provide a new configuration of the magnetic structure that overrides an existing configuration and requires the determination of a new actuator setpoint.

[0128] Decision step 602 periodically verifies whether a (valid) interrupt signal requiring adjustment of the control trajectory has been received. If there is no valid interrupt signal at this moment, or if it is not received, the control unit proceeds to step 601 and waits for a possible interrupt signal to arrive. If a valid interrupt signal is received in step 602, the control unit proceeds to step 603.

[0129] In step 603, the control unit calculates the change to the setpoint for at least one actuator that is caused, or likely to be caused, by a parameter change. The change may be calculated as a correction factor used as a scaling factor when adjusting the control trajectory in step 605. The likelihood may be defined by a set of rules indicating which thresholds are exceeded for one or more parameters being changed, requiring recalculation of the actuator setpoint. Rule-based recalculation of setpoints and thresholds may be provided based on user preferences and / or from the system specification.

[0130] In step 604, the control unit updates the setpoint for at least one actuator in accordance with the calculated change to the setpoint. The updated value can be written back to at least one storage device, for example, by overwriting a previously stored setpoint in a particular table, or by creating a new table with the updated setpoint as an entry. A local copy of the updated setpoint and / or a reference to a memory location in at least one storage device containing the updated setpoint can be maintained within the control unit.

[0131] Next, in step 605, the control unit adjusts the control trajectory for at least one actuator according to the updated setpoint. The control unit may then return to step 601 if the sputter coating process is still active and running.

[0132] In a variation of this method, the change in actuator setpoint is not calculated, but a more appropriate setpoint is loaded from at least one memory device. The interrupt signal may include an identifier, or may allow the derivation of an identifier that the control unit uses to access a specific memory location or region within at least one memory device, for example, an identifier that enables access to a specific table of actuator setpoints that are compatible and optimal with respect to parameter changes.

[0133] The present invention is illustrated and described in detail in the drawings and the preceding description, but such illustrations and descriptions should be considered illustrative or exemplary and not limiting. The preceding description describes in detail specific embodiments of the present invention. However, it should be understood that the present invention can be carried out in many ways, regardless of how much detail is shown in the preceding text. The present invention is not limited to the disclosed embodiments.

[0134] Other variations of the disclosed embodiments can be understood and practiced by those skilled in the art practicing the claimed invention from the study of the drawings, disclosures, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude plurals. A single processor or other unit may perform the functions of several items described in the claims. The mere fact that certain measures are enumerated in mutually distinct dependent claims does not imply that combinations of these measures cannot be used advantageously. Any reference numerals in the claims should not be construed as limiting in scope.

Claims

1. An assembly (100) for controlling the magnetic structure (111) of a magnetron sputtering apparatus, wherein the assembly is connectable to the end block (438) of the magnetron sputtering apparatus. An elongated support structure (150) and connected to the support structure, The system comprises at least one control unit (130), at least one storage device (140), and at least one actuator (120a to d) for locally adjusting the position and / or orientation of the magnetic structure (111), The input connector (32) of at least one control unit is operably connectable to trigger units (432; 433; 434; 440a-c) located away from the assembly, The at least one control unit, - Loading a control input from the at least one storage device (140) such that the control input includes a set point for the at least one actuator, or data necessary for calculating a set point for the at least one actuator. - Determining the control trajectory for at least one actuator based on the control input, - To generate a control signal or control signal sequence for at least one actuator according to the control trajectory, - Synchronizing the transmission of the control signal or the control signal sequence to the driver circuit (127) of the at least one actuator with at least one trigger signal from the trigger unit, wherein the at least one trigger signal indicates the position of the substrate relative to the magnetic structure. An assembly configured to perform the following actions.

2. The assembly according to claim 1, wherein the magnetic structure (111) is connectable to a support member of the support structure (150) via at least one actuator (120a to d).

3. The at least one control unit (130) Loading a record of one or more process variables related to the magnetron sputtering apparatus from at least one storage device or from the trigger units (432; 433; 434; 440a-c) via the input connector (32), The assembly according to claim 1 or 2, further configured to adjust the control trajectory based on the record of one or more process variables.

4. The at least one control unit (130) Receiving substrate trajectory information related to the movement of the substrate as it passes through the assembly, The assembly according to any one of claims 1 to 3, further configured to determine the time interval between the transmission of two consecutive control signals in the control signal sequence based on the substrate trajectory information.

5. The assembly according to claim 4, wherein the at least one control unit (130) is further configured to load the substrate trajectory information from the at least one storage device or to extract the substrate trajectory information from the trigger signals from the trigger units (432; 433; 434; 440a-c).

6. The assembly according to claim 4 or 5, wherein the at least one control unit (130) is further configured to extract substrate position and / or substrate speed information transmitted by the trigger signal from the trigger unit (432; 433; 434; 440a-c), and to calculate a delay for transmitting a control signal from the control signal sequence to the trigger signal from the trigger unit based on the substrate position and / or substrate speed information.

7. The assembly according to any one of claims 1 to 6, wherein the control input includes substrate surface topography-related data, and the at least one control unit (130) further comprises a data processing subunit configured to calculate a setpoint for the at least one actuator based on the surface topography-related data.

8. The at least one control unit (130) Extracting substrate geometry information and / or sputtering process conditions transmitted by the trigger signal from the trigger unit (432; 433; 434; 440a-c), The assembly according to any one of claims 1 to 7, further configured to identify the control input to be loaded from the at least one storage device (140) based on the substrate geometry information and / or sputtering conditions.

9. The assembly according to any one of claims 1 to 8, comprising one or more control units (130) and a plurality of actuators for locally adjusting the position and / or orientation of the magnetic structure (111) at different locations along the support structure (150), wherein the one or more control units are configured to generate the control trajectories for the plurality of actuators.

10. The assembly according to any one of claims 1 to 9, wherein the at least one actuator (120a to d) is an electrically driven actuator, a pneumatic actuator, or a hydraulic actuator.

11. The assembly according to any one of claims 1 to 10, wherein the at least one storage device (140) is a persistent memory device.

12. A magnetron sputtering apparatus for sputter coating of non-flat substrates, A magnetron sputtering apparatus comprising: an assembly according to any one of claims 1 to 11; a magnetic structure (111) coupled to the support structure (150) via at least one actuator (120a to d); a sputtering target (436) substantially coaxially mounted on the support structure (150); and an end block system (438) connected to the assembly and the sputtering target (436).

13. An in-line vacuum sputtering coating apparatus (400) for generating repeatable and reproducible coating profiles on a moving substrate, A magnetron sputtering apparatus according to claim 12, A transport system (434) for moving the substrate (435) through the magnetron sputtering apparatus, The system comprises a trigger unit for generating a trigger signal that transmits information related to the position of a substrate along the transport system, An inline vacuum sputter coating apparatus, wherein the at least one trigger unit is configured to transmit a trigger signal to the at least one control unit when it detects an event that positions individual substrates along the transport system.

14. A method (500) for sputter coating a moving substrate using a magnet bar assembly for a magnetron sputtering apparatus, wherein the magnet bar assembly comprises at least one actuator for locally adjusting the position and / or orientation of the elongated magnetic structure of the magnet bar assembly, and the method -Storing control inputs in a storage device disposed inside the magnet bar assembly, wherein the control inputs include set points for the at least one actuator or data necessary for calculating set points for the at least one actuator (501), - Loading the control input from the storage device to the control unit disposed inside the magnet bar assembly (502), - Receiving an external trigger signal from a trigger unit located away from the magnet bar assembly, wherein the external trigger signal indicates the position of the substrate relative to the magnetic structure (505), - Execute a control program on the control unit to determine a control trajectory for the at least one actuator based on the control input (503), generate a control signal or control signal sequence for the at least one actuator according to the control trajectory (504), and synchronize the transmission of the control signal or control signal sequence to the driver circuit of the at least one actuator with the external trigger signal (506), A method comprising (507) adjusting the position and / or orientation of the magnetic structure while sputter coating the moving substrate by driving the at least one actuator in accordance with the control signal or the control signal sequence.

15. The method according to claim 14, wherein storing control inputs in the storage device includes storing sputtering process parameters and / or surface topography-related data for coating a non-planar substrate surface, and the method further includes calculating the setpoint for the at least one actuator based on the process parameters and the surface topography-related data.

16. Calculating the change to the setpoint for the at least one actuator caused by changing at least one of the process variables of the sputter coating method and the parameters of the magnetron sputtering apparatus comprising the magnet bar assembly, Updating the setpoint for the at least one actuator stored in the storage device in accordance with the change to the setpoint, The method according to claim 14, further comprising adjusting the control trajectory for the at least one actuator in accordance with the change to the setpoint.

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