DE102014102877B4 - Method for setting up a magnet arrangement of a magnetron - Google Patents

Abstract

According to various embodiments, a method for setting up a magnet arrangement of a magnetron may include: determining a spatial temperature distribution which adjusts for the magnet arrangement and / or the cathode during operation of the magnetron, adapting a plurality of magnets of the magnet arrangement taking into account the spatial temperature distribution, so that a spatial magnetic field distribution, which takes into account the spatial temperature distribution, is provided over a surface of the cathode.

Description

The invention relates to a method for setting up a magnet arrangement of a magnetron.

In general, a substrate can be coated by means of cathode sputtering (so-called sputter deposition). Further, in magnetron sputtering, the sputtering process (the sputtering process) can be assisted by means of a magnetic field. For example, a cathode used for sputtering (a so-called target) may have a surface to be sputtered which may be exposed to a processing area within a vacuum chamber during sputtering so as to sputter (sputter) it by means of a plasma provided in the processing area. can be. Over or on the side of the cathode facing away from the processing area, a magnet arrangement can be or are provided by means of which a magnetic field is generated over the surface of the cathode to be sputtered, which influences the sputtering process. For example, an arrangement of cathode and magnet assembly may be part of a magnetron, where the magnetron may be configured as an elongated planar magnetron or as a double planar magnetron, as an elongate tubular magnetron, or as an elongate double tube magnetron, e.g. B. with a length of more than one meter. Conventionally, the magnet arrangement for a magnetron is set up (chamfered) such that the most homogeneous possible magnetic field is provided along the longitudinal extent of the magnet arrangement and the cathode. In reactive magnetron sputtering, a reactive gas may or may not be provided within the processing region in which the sputtered target material propagates, wherein the reactive gas reacts with the sputtered target material and forms a coating on a substrate, e.g. For example, a metal may be sputtered, and by introducing oxygen and / or nitrogen, a metal oxide, a metal nitride and / or a metal oxynitride may be deposited on a substrate. In general, reactive sputtering processes may very much depend on variations in process parameters, so that it may be difficult to provide a predefined (controlled) reactive sputtering process.

In US 2014/0 054 168 A1 a magnet assembly for a magnetron is described, wherein the magnet assembly is arranged to reduce the cross-corner effect. In this case, the magnet arrangement is modified at the end portions of the carrier, for. Example by means of specially designed shim elements or a corresponding arrangement of a plurality of magnets.

In US 5,865,970 A a magnet assembly for a magnetron is described, wherein the magnet assembly between the rows of magnets with NSN configuration further magnets for generating a corresponding magnetic field over the target material to be sputtered.

In US 2004/0 163 951 A1 a magnet array for a planar magnetron is described, wherein the entire magnet assembly for generating a corresponding magnetic field over the target material to be atomized relative to the target can be tilted. Furthermore, this document describes a magnet arrangement, wherein the magnets of the magnet arrangement have beveled surfaces, which are directed in the direction of the target material.

In US 6,228,236 B1 For example, a magnet array for a planar magnetron is described wherein the magnets of the magnet array have a particular in-plane spatial arrangement for generating a corresponding magnetic field over the target material to be sputtered.

According to various embodiments, a magnet arrangement is provided for a magnetron, the magnet arrangement having an inhomogeneous magnetic field distribution (transverse to the longitudinal direction) along its longitudinal direction or the magnet arrangement having a magnetic field with a magnetic field gradient along the longitudinal direction of the magnet arrangement. Illustratively, it has been recognized, for example, that the cathode and / or the magnet arrangement (the magnetron) during sputtering (for example, at high powers) have no uniform temperature, but a temperature gradient along the longitudinal direction of the cathode and / or the magnet assembly. The strength of the magnetic field of the magnets, in turn, can be a function of temperature. In this case, the temperature gradient may be influenced by the total power of the sputtering process (eg regulated by means of a generator which provides the power between anode and cathode) and / or by the local power density along the cathode. The total power and / or the local power density can, for example, in turn be influenced by the amount of reactive gas supplied, the reactive gas partial pressure and / or the spatial distribution of the reactive gas in the processing area (or at the cathode), wherein, in addition, the reactive gas consumption in turn has an influence on the Can have sputtering power. Furthermore, further substantial influences on the reactive sputtering can result from the coolant guidance (eg the coolant temperature and / or the coolant flow) within the magnetron for cooling the cathode and / or the magnet arrangement. Clearly, the reactive sputtering results in a complex correlated parameter set (operating parameter set or set of parameters), so that the operating point of a reactive sputter coating system can be difficult to control or regulate.

Furthermore, it has been recognized that a variation in the temperature of the magnet assembly (or the respective magnets of the magnet assembly) of a few Kelvin can cause the operating point of the magnetron to shift so that layers are deposited during the reactive sputtering process whose layer properties are different from the given layer properties may differ.

One aspect of various embodiments can be seen illustratively in compensating for a temperature gradient along the cathode and / or the magnet assembly by adjusting the magnet assembly according to the temperature gradient. Thus, for example, influences on the reactive sputtering process caused due to uneven distribution of the temperature of the cathode and / or the magnet assembly can be reduced. Clearly, it has been recognized that a temperature gradient in the cathode and / or in the magnet arrangement can be compensated by means of a magnetic field gradient in the magnetic field provided by the magnet arrangement.

According to various embodiments, a method for setting up a magnet arrangement of a magnetron may comprise determining a spatial temperature distribution which adjusts for the magnet arrangement and / or the cathode during operation of the magnetron, and adapting a plurality of magnets of the magnet arrangement taking into account the spatial temperature distribution, such that a spatial magnetic field distribution, which takes into account the spatial temperature distribution, is provided over a surface of the cathode.

In addition, determining the spatial temperature distribution may comprise determining a first temperature which occurs when the magnetron is operated in a first region of the magnet arrangement and / or the cathode, and determining a second temperature which results when the magnetron is operated in a second region Magnetic arrangement and / or the cathode adjusts, wherein the first region has a distance from the second region and wherein the first temperature is different from the second temperature.

Furthermore, determining the spatial temperature distribution may include determining a temperature gradient.

Furthermore, the adaptation of the magnet arrangement, for example for compensating for this publication, may include a magnetic field gradient which is rectified in relation to the temperature gradient over the surface of the cathode by means of the magnetic field generated by the magnet arrangement. Thus, during operation of the magnetron, a temperature increasing spatially along a direction may be compensated for by providing a magnet assembly for operation such that it provides a magnetic field increasing in the same direction at room temperature or at a constant ambient temperature. Thus, in the operation of the magnetron, due to the spatial temperature distribution (of the temperature gradient), the provided magnetic field of the magnetic arrangement can be compensated so that the magnetic field provided by the magnet arrangement during operation of the magnetron is homogeneously distributed over a surface of the cathode along the direction. Clearly, the magnet arrangement of the magnetron can be adapted when the magnetron is not in operation, although in this adjustment of the magnet arrangement a temperature state of the magnetron is taken into account during operation, so that during operation of the magnetron the provided magnetic field corresponds to a predefined magnetic field distribution.

Alternatively, the magnet arrangement can also be adapted during the operation of the magnetron.

The adaptation of the plurality of magnets may include, for example: for at least one of the plurality of magnets, varying the magnetization thereof. The adjustment of the plurality of magnets may further include, for example, for at least one of the plurality of magnets, altering its position and / or orientation relative to the surface (to be sputtered) of the cathode.

Further, the adaptation can be carried out in that in each case in a first region of the magnet arrangement, in which a larger temperature sets during operation of the magnetron, a magnet is arranged with a larger magnetization, as in a second region of the magnet arrangement, in which Operation of the magnetron sets a lower temperature.

Furthermore, the adaptation can take place in that in each case in a first region of the magnet arrangement, in which a larger temperature sets during operation of the magnetron, a magnet is provided with a smaller distance to the surface of the cathode than in a second region of the magnet arrangement, in which sets a lower temperature during operation of the magnetron.

Further, the fitting may be done by tilting or placing the entire magnet assembly tilted relative to the surface (to be sputtered) of the cathode.

According to various embodiments, at each of the two end portions of the elongate magnet assembly, there may be provided an area in which a plurality of further magnets are arranged along a curved path, so that the so-called reverse regions of the race track may be provided. Illustratively, the magnet assembly described herein can create the linear or elongate regions of a race track.

For example, a magnetron arrangement may comprise a carrier, a plurality of magnets arranged on the carrier, wherein the plurality of magnets are arranged and arranged relative to one another along a direction such that a magnetic field can be provided over a cathode surface of a magnetron arranged relative to the carrier wherein the plurality of magnets each have different magnetizations from each other so that the magnetic field generated by the plurality of magnets increases along the direction.

Further, the carrier may have a spatial extent along a longitudinal direction in a range of about 1 m to about 5 m.

Furthermore, the respective magnetization of the plurality of magnets may increase along the longitudinal direction of the carrier.

The respective magnetization of the plurality of magnets may, for example, increase from a base value by more than about 0.15%. Further, for example, the respective magnetization of the plurality of magnets may increase from a base value by more than about 0.5%. Further, for example, the respective magnetization of the plurality of magnets may increase from a base value by more than about 0.5% and by less than about 5%.

According to various embodiments, the base value of the plurality of magnets may be adjusted according to the determined temperatures (eg, the lowest temperature).

Further, the basic value may be in a range of about 1 mT to about 1 T, for example. Further, the basic value may be, for example, in a range of about 50 mT to about 500 mT.

Further, the magnetron may be a tubular magnetron and the cathode may be a tubular cathode accordingly. Further, the magnetron may be a double-tube magnetron and have a plurality of (two) tube cathodes.

According to various embodiments, the magnetron arrangement described herein may be used in a reactive magnetron sputtering process.

Further, at least a first magnet of the plurality of magnets arranged along the longitudinal direction of the carrier may have a first magnetization, and at least a second magnet of the plurality of magnets arranged along the longitudinal direction of the carrier may have a second magnetization, wherein a ratio of the first magnetization to the second magnetization is greater than 1,0015 or less than 0.9985 (eg, for Sm ₂ Co ₁₇ magnets and a temperature difference of about 5 K occurring during operation). Further, the ratio of the first magnetization to the second magnetization may be greater than 1.003 or less than 0.9970 (eg, for Sm ₂ Co ₁₇ magnets and a temperature difference of approximately 10 K occurring during operation). Further, the ratio of the first magnetization to the second magnetization may be greater than 1.006 or less than 0.9940 (eg, for Sm ₂ Co ₁₇ magnets and a temperature difference of approximately 20 K occurring during operation).

Further, at least a first magnet of the plurality of magnets arranged along the longitudinal direction of the carrier may have a first magnetization, and at least a second magnet of the plurality of magnets arranged along the longitudinal direction of the carrier may have a second magnetization, wherein a ratio of the first magnetization to the second magnetization is greater than 1.01 or less than 0.99 (eg, for NdFeB magnets and a temperature difference between the first and second magnets during operation of about 10 K). Further, the ratio of the first magnetization to the second magnetization may be greater than 1.03 or less than 0.97 (eg, for NdFeB magnets and a temperature difference between the first and second magnets of approximately 20 K occurring during operation). Further, the ratio of the first magnetization to the second magnetization may be greater than 1.015 or less than 0.985 (eg, for NdFeB magnets and a temperature difference between the first and second magnets of approximately 5 K occurring during operation).

Further, the ratio of the first magnetization to the second magnetization may be in a range of about 0.9 to about 1.1, e.g. In a range of about 0.95 to about 1.05.

According to various embodiments, the type of magnets (the material of the magnets and / or the shape and size of the magnets) may illustratively be taken into account when adjusting the magnets. In this case, for example, a material-specific temperature coefficient can be considered or be described, which describes the dependence of the magnetization of the temperature. For example, for NdFeB (in a temperature range of about 20 ° C to about 100 ° C), the material-specific temperature coefficient may be about -0.1% / K. For example, the material specific temperature coefficient for Sm _x Co _y magnets (eg, Sm ₂ Co ₁₇ magnets) (in a temperature range of about 20 ° C to about 100 ° C) may be about -0.03% / K.

According to various embodiments, the plurality of magnets of the magnet assembly may be rare earth magnets, i. H. have at least one element of rare earths.

For example, a magnetron assembly may include a carrier, a plurality of magnets disposed on the carrier, wherein a first set of the plurality of magnets is disposed along a first direction, and wherein at least a second set of the plurality of magnets is disposed along at least one second direction; such that a magnetic field can be provided over a cathode surface of a cathode arranged relative to the carrier, wherein the first direction extends at an angle to the second direction. Thus, the magnetic field generated across the cathode surface may have a gradient in field strength along the first direction.

Further, the angle between the first direction and the at least one second direction may be in a range of about 0.05 ° to about 10 °.

Embodiments of the invention are illustrated in the figures and are explained in more detail below.

Show it

1A shows a relationship between the burning voltage during reactive sputtering and the resistivity of a layer produced according to the operating parameters with increasing useful life of the target, according to various embodiments;

1B shows a relationship between the burning voltage during reactive sputtering and the resistivity of a layer produced according to the operating parameters using different cooling water temperatures, according to various embodiments;

1C shows a scale of in 1A and 1B shown measurement data using a shift of the burning voltage by a value (offset) as a scaling rule, according to various embodiments;

2 shows a method for setting up a magnet arrangement of a magnetron in a schematic flow diagram, according to various embodiments;

3A to 3E each show a magnet arrangement or a magnetron arrangement in a schematic view, according to various embodiments;

4 shows details of a magnetron arrangement and a method for setting up a magnet arrangement of a magnetron in a schematic view, according to various embodiments; and

5 shows a magnet assembly or a magnetron arrangement in a schematic view, according to various embodiments.

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "front", "rear", etc. is used with reference to the orientation of the described figure (s). Because components of embodiments can be positioned in a number of different orientations, the directional terminology is illustrative and is in no way limiting. It should be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. It should be understood that the features of the various exemplary embodiments described herein may be combined with each other unless specifically stated otherwise. The following detailed description is therefore not to be construed in a limiting sense, and the scope of the present invention is defined by the appended claims.

As used herein, the terms "connected," "connected," and "coupled" are used to describe both direct and indirect connection, direct or indirect connection, and direct or indirect coupling. In the figures, identical or similar elements are provided with identical reference numerals, as appropriate.

In reactive sputtering, coating a substrate (or support) with a layer (coating) having the appropriate layer properties may be accomplished by placing the sputter assembly in an operating point or operating condition and / or at an operating point. The operating point may specify the necessary operating parameters of the sputtering arrangement (eg, a substrate transport speed, a target rotational speed, generator sizes, gas pressure, materials, etc.) such that a corresponding layer having the respective desired or required properties or properties according to a specification (eg specific electrical resistance of the layer, chemical composition of the layer, layer thickness distribution of the layer on the surface of the substrate, optical properties of the layer, etc.) can be produced. In this case, deviations of the sputtering process from an operating point globally for the entire sputtering process and / or locally in a region of the sputtering process chamber can be compensated for by controlled feeding (trimming) of a process gas by means of a process gas feed into the relevant area of the sputtering process chamber.

A corresponding sputtering arrangement for providing a reactive sputtering process may include, for example, at least one generator for providing an electrical voltage (the burning voltage) to the cathode and the corresponding electrical current between the cathode and an anode. The electric current, I, flowing at a respective applied voltage, U, between the cathode and the anode may be dependent on the gases (eg, the composition or pressure of the process gas) in the vacuum chamber. Thus arise for the generator and for supplying the process gas different modes or

Control options and / or control options to set an operating point (eg a power).

In this case, a sputtering arrangement for providing a reactive sputtering process can have one or more vacuum chambers, wherein at least one of the vacuum chambers can be a sputtering process chamber. For example, the sputtering arrangement can be configured as a so-called batch coating system in which substrates can be successively coated batch by batch. Furthermore, the sputtering arrangement can be configured as a so-called in-line coating system, wherein a substrate (eg plate-shaped substrates or a plurality of plate-shaped substrates by means of substrate carriers as so-called endless substrate) passes through a plurality of vacuum chambers (or compartments) on a transport system can be performed. In this case, the substrate can be introduced into the sputtering arrangement by means of at least one lock chamber and / or brought out of the sputtering arrangement. Further, the sputtering assembly may be configured as a so-called air-to-air coating equipment or as a belt coater, wherein the substrate may, for example, be transported from roll-to-roll through the at least one sputtering process chamber.

Further, during the sputtering process (eg, during operation of a sputtering cathode), material (target material) may be sputtered from a cathode (the target) with the sputtered material propagating in a direction away from the cathode. The area at the cathode where the sputtered material propagates may be referred to as the processing area. Furthermore, the sputtering arrangement can have a transport device, by means of which a substrate can be guided through the sputtering process chamber or through the processing area or at least into the processing area, so that at least part of the substrate in the processing area can be coated by means of the cathode.

During a sputtering process (a sputtering process), a plasma may be or may be provided in the processing area, e.g. Example by providing an electric field by means of the cathode, wherein the provided electric field extends at least partially into the processing area. By means of the plasma, the target (the cathode) can be atomized (for example due to the ion bombardment of the target with the ions formed in the plasma). To generate the plasma, at least one working gas (eg argon or another noble gas or a gas suitable as working gas) may or may not be provided in the sputtering process chamber. Furthermore, at least one reactive gas may or may not be provided in the sputtering process chamber for reactive sputtering.

In magnetron sputtering (a magnetic field assisted sputtering process), the plasma formation may be assisted by a magnet assembly (or by a magnet system), where the magnet assembly may be or may be arranged such that a magnetic field generated by the magnet assembly at least partially extends into the processing region. Due to a superimposition of the provided electric field with the generated magnetic field, the movement of charge carriers (eg electrons) in the processing region can be changed in such a way (eg due to the acting Lorentz force and a drift movement of the electrons) that the ionization rate of the plasma forming Gas and thus the plasma density of the plasma formed is increased. Thus, for example, the required pressure of the plasma-forming gas to provide a predefined ionization rate can be reduced (as compared to sputtering without magnetization).

According to various embodiments, the magnet arrangement may be arranged on (near) or above the surface of the target (target surface) facing away from the processing area. In this case, the magnet arrangement can be set up in this way or a large number of magnets can be arranged spatially in such a way that an ionization area is provided in the processing area, in which the plasma forms, eg. For example, the plasma may be stationary when the magnet assembly is stationary. The ionization region may also be designated as a plasma region and / or race track.

By means of adaptation of the magnet arrangement, a predefined shape and / or size of the ionization region and thus of the generated plasma can be adjusted, and / or the geometry of the plasma generated in the ionization region can be influenced. By way of example, the magnets of the magnet arrangement can be or are arranged relative to one another in such a way that an elongated (longitudinally extending) ionization area arises. Such a longitudinally extending ionization region may, for example, have a length in a range of approximately several centimeters to approximately several meters, for example in a range of approximately 1 m to approximately 4 m. In this case, the shape of the ionization region can correlate with the spatial arrangement and / or the position (relative to the magnetic poles) of the magnets of the magnet arrangement.

When sputtering the target or the target surface of the target, the removal of material may depend on the relative arrangement of the target to the ionization region. In order to achieve a uniform material removal of the target material, for example, the target surface can be moved relative to the magnet arrangement and the ionization region. According to various embodiments, the target may be tubular, wherein the magnet assembly may be disposed, for example, within the tubular target (target tube or tube cathode), and the target tube may be rotated about the longitudinal axis of the target tube, for example. A magnetron having a tubular target or having multiple (eg, two) tubular targets is also referred to as tube magnetron (eg, double tube magnetron).

In this case, the longitudinally extending ionization region on and / or over the outer lateral surface of the target tube can run essentially parallel to the longitudinal axis of the target tube.

Furthermore, the target can have a planar (so-called planar) target surface, wherein the ionization region can be set up in such a way that the most efficient possible utilization of material and / or a homogeneous distribution of the plasma suitable for coating a substrate arises.

The magnet arrangement may further be arranged such that a longitudinally extending ionization region is formed by means of the magnet arrangement, for example a plurality of magnets may be correspondingly arranged in a line, wherein additional magnets of the magnet arrangement may or may be arranged such that a plurality (eg B. two) longitudinally extending Ionisierbereiche are interconnected. By way of example, the magnet arrangement can be or be set up such that the ionization region runs along a closed path or along several closed paths or that a plasma film formed is closed. For example, the magnet arrangement can be set up such that the ionization region (in which the plasma can be generated with the ions of the process gas and electrons) runs along a multi-sided polygon (eg quadrangle), which for example can have rounded corners. A closed path for the ionization region or a closed path of the plasma can be referred to as a race track, along which clearly the electrons of the plasma can drift (drift motion).

In one embodiment, the race track may have two linear regions which are interconnected at their ends by means of a curved region. In this case, the magnet arrangement can be or be set up such that the linear regions of the race track run parallel to one another.

In general, magnetron sputtering or reactive magnetron sputtering can be used in various modes (operating modes) are performed, for. In so-called DC mode (DC sputtering), in AC mode (AC sputtering, such as MF sputtering or RF sputtering), in pulsed mode (high energy pulse magnetron sputtering), unipolar or bipolar pulsed discharge, both with one electrode and with several electrodes (cathodes and / or anodes).

When sputtering the cathode heat can be entered into the cathode, z. As a function of the sputtering performance of the target material (etc.), so that the cathode must be cooled, for example. In this case, the cathode can be cooled by means of a cooling device, which leads cooling water in thermal contact with the cathode. In this case, the cooling water can gradually warm during the flow, for example, it absorbs heat from the cathode. Illustratively, the cooling water within the cooling device for the cathode along the direction of flow may have a temperature gradient, for. B. of more than 5 K, z. B. of more than 10 K, z. B. of more than 15 K, z. B. of more than 20 K, z. B. of more than 25 K, z. B. of more than 30 K.

According to various embodiments, the cooling water, for. B. in tubular cathodes, are also passed directly through the cathode or flow directly through the cathode. Furthermore, the cooling water can also be successively (serially) passed through several cooling devices of several cathodes, z. B. through two tube cathodes of a double tubular magnetron, so that the temperature and / or the temperature gradient of the cooling water in the plurality of cathodes may differ.

One aspect of various embodiments can be clearly seen in considering these different temperatures of cooling water and / or temperature gradients in the cooling water in the construction and / or calibration of the sputtering assembly or the magnetron or magnet assembly.

Conventionally, a magnet arrangement (for example a carrier with a plurality of magnets, a so-called magnet bar) for magnetrons is optimized in such a way that spatially homogeneous field distribution can be provided for a predefined field strength. In the process, when manufacturing or configuring a magnet bar (a magnet arrangement), care is taken, for example, to set the magnetic field as uniformly as possible over the entire magnet bar (over its longitudinal extension). When using the magnet bar in a magnetron sputtering process, the transverse distribution of the plasma, the plasma properties and / or the layer properties of a deposited layer (transverse to the transport direction of the substrate during coating) by means of so-called shimming (adjusting the height of the magnets of the magnet bar) due to the change of Magnetic field influenced at the target surface of the cathode. This process is assisted by the so-called trimming, whereby the transverse distribution of the plasma, the plasma properties and / or the layer properties of a deposited layer is influenced by controlled feeding of process gas (reactive gas and / or working gas) into the processing area of a magnetron coating installation. In reactive processes, the result of shimming is very difficult to detect because the reactive gas distribution and the distribution of the suction power have significant effects on the operating point and thus, for example, the shim result is completely covered.

Conventionally, in a production of a magnetic bar, the temperatures occurring during coating are not sufficiently taken into account and their production and / or configuration (calibration or shimming) takes place, for example, at room temperature. In general, for example, it is assumed that the quality (eg the predefined spatial distribution of the magnetic field along the longitudinal extent of the magnet bar) of the magnetic field also remains constant in the target through which the cooling water flows.

According to various embodiments, it has been recognized that when operating a magnetron, the temperature of the individual magnets (eg different from each other) may change in each case, eg. B. compared with the temperature conditions during shimming, and that the magnets have a temperature coefficient in terms of their field strength. Since, therefore, the magnets are exposed to different temperature conditions during shimming than during operation of the magnetron with the magnet bar, the shimming can lead to an insufficient result if the temperature conditions of the magnets of the magnetron are disregarded.

According to various embodiments, a magnet bar (a magnet arrangement) is provided which can already compensate for a temperature gradient along the cathode and / or along the magnet bar during construction. The temperature gradient can, for example, change the magnetization of the magnets of the magnet bar and thus the magnetic field generated by the magnets. Further, the temperature gradient at constant pressure within the processing area may cause a location-dependent particle density and thus a location-dependent ion density. Such effects resulting from a temperature gradient along (the longitudinal extension) of the cathode and / or along the magnet bar may be as herein be compensated described by adjusting the magnet bar.

In the following 1A to 1C For example, the direct effect of changing the temperature of the cooling water (the cooling water temperature) by, for example, a few Kelvin (eg, +/- 5K) is exemplified by a reactive sputtering process of aluminum-doped zinc oxide (ZnO: Al) 1B ). For processes with high power (sputtering power) per meter (power density) and long targets (eg with a length in a range of about 1 m to about 5 m), the cooling water may be heated up to several tens of K (eg, heating the cooling water from the predefined cooling water temperature in a range of about 5 K to about 30 K, or even more than 30 K). This can lead to a temperature gradient along the target and thus also to a magnetic field gradient if the magnet arrangement does not take these temperature changes into account. This effect can play an important role in reactive processes (reactive sputtering processes), since reactive sputtering processes can, for example, react sensitively to a changed operating point (for example, the layer properties of the layers produced may deviate from a specification, for example from a predetermined one) electrical conductivity and / or predetermined optical properties). Conventionally, reactive sputtering processes with targeted trimming (controlling the reactive gas supply to the processing area during sputtering) can be kept stable. However, since trimming can simultaneously serve to compensate for other effects (suction power distribution, chamber geometry, anode access, substrate movement), it may be necessary or helpful to compensate in advance for the temperature effect described herein and / or the effects of the temperature effect on the temperature effect Minimize operating point of the magnetron.

According to various embodiments, a method of setup (fabrication and / or calibration) and a magnetron arrangement are provided such that during a high power sputtering process (e.g., more than 20 kW per meter of cathode or more than 30 kW per meter Cathode) to ensure a homogeneous magnetic field in its longitudinal extent (for example, without significant gradients from the cold to the warm end of the target.) For example, in double cathodes, where the targets are flowed through in series by the cooling water, also the temperature difference in the cooling water between the targets themselves would be respected since the two targets would otherwise operate at different operating points in the case of the reactive process.

Clearly, during operation of the magnetron, a local shift of the operating point of the magnetron along its longitudinal extent should be avoided due to the inhomogeneous cooling water temperature which arises.

According to various embodiments, a field strength graded magnet bar (multi-magnet carrier or magnet assembly) is used. Under normal conditions (without temperature influences during the operation of the magnetron), a gradient along the target in the magnetic field is measured at the target surface, during operation the gradient is compensated for by the power consumption (heat absorption) in the cooling water and the resulting temperature gradient. With two targets connected in series in the cooling water, not only a gradient in the magnetic field but also a different strength of the magnetic field can be realized at the targets. For this, the approximate temperature gradient can be known or determined during the process, so that the temperature gradient can be compensated for by means of adaptation (for example by means of adjusting the intensity) of the magnetic field. According to various embodiments, an in situ shimbares magnet bar can be used for this purpose, which can then be placed obliquely in the target, depending on the flow of cooling water and the entry of power.

In 1A is a relationship between the burning voltage 104 (U in V) in reactive sputtering and resistivity 102 (p in μΩcm) of a corresponding layer produced by the burning voltage (using a power control), wherein the (connected by lines) measurement data 100 each represent measurement series, which were determined temporally successively and thus include the useful life of the target as a variable variable. It can be seen that with increasing target age (with increasing consumption of the target material or with a longer service life) lower burning voltages 104 must be used to ensure a constant operating point, ie, in each case one layer with the corresponding electrical resistance 102 deposit.

Clearly, the layer properties change for different operating voltages 104 with increasing target age. In other words, the layer properties of a deposited layer can be changed with increasing target age while the firing voltage is kept constant. The operating point is stabilized in the selected process via the burning voltage.

As in 1A is illustrated, there is a clear relationship 100 between layer property 102 (specific electrical resistance) and burning voltage 104 (For example, a respective lower specific electrical resistance with increasing burning voltage U). This dependence 100 shifts ( 111 ) with increasing target age to lower burning voltages 104 because due to the material removal of the target, the magnetic field at the target surface increases (due to the smaller distance between the target surface and the magnet arrangement).

This finding was confirmed, for example, by a stronger magnet arrangement (stronger magnet bars) 100a were used for the reactive sputtering process, whereby the dependence between layer property 102 and burning voltage 104 to lower burning voltage values 104 is moved.

According to various embodiments, in the reactive sputtering, the cooling water supply temperature (the temperature of the cooling water before the introduction of the cooling water into the cooling device of the magnetron or into the magnetron) can be controlled, e.g. B. be set to a predefined value. At the in 1A For example, the cooling water inlet temperature was constant for all experiments (approximately 25 ° C).

1B illustrates three workpoint series 110a . 110b . 110c showing the relationship between layer property 102 (specific electrical resistance) and burning voltage 104 , where the measurements of the three work-point series were carried out immediately one after the other so that the influence of the target aging (cf. 1A ) is negligible or negligible.

It was used to determine the first workpoint series 110a the layer properties 102 depending on the particular operating voltage used 104 shown, with the first operating point series 110a was carried out at a cooling water inlet temperature of about 20 ° C. The second workpoint series 110b was carried out at a cooling water inlet temperature of about 25 ° C and the third operating point series 110c was performed at a cooling water supply temperature of about 30 ° C.

It was recognized that the field strength of the magnetic field generated by the magnet of the magnet bar decreases with warmer cooling water and increases with cooling cooling water. The shift of the property curve 110 due to the only 5 ° C changed cooling water temperature is in the measurement series 110a . 110b . 110c to recognize. This corresponds to a colder cooling water temperature 110a a more eroded target and a warmer cooling water temperature 110a a less eroded target.

Thus, it has been recognized, for example, that both the temperature of the cooling water and the target age have an influence on the dependence of the layer property 102 from the burning voltage 104 cause.

It has also been recognized, such as in 1C illustrates that the principal dependence of the layer property 102 from the burning voltage 104 does not change due to the changed magnetic field (due to the changed cooling water temperature and / or the target age). For this purpose, for example, the series of measurements at different cooling water temperatures and the series of measurements with increasing target age were superposed on each other 120 by shifting the burn voltage values of the respective measurement series by one value (offset). It can be clearly seen from this that the temperature effect (as in 1B illustrated) can be compensated by means of an adaptation of the magnet arrangement, and vice versa.

Due to this finding, according to various embodiments, a method 200 for establishing a magnet arrangement of a magnetron, as in 2 illustrated, wherein the method may include: in 210 Determining a spatial temperature distribution, which adjusts for the magnet arrangement and / or the cathode during the operation of the magnetron, and, in 220 Adjusting a plurality of magnets of the magnet assembly in consideration of the spatial temperature distribution so that a spatial magnetic field distribution taking into account the spatial temperature distribution is provided over a surface of the cathode.

According to various embodiments, as described above, the magnet assembly may be integrated into a magnetron or provide a portion of a magnetron, wherein the magnetron may be utilized in a vacuum chamber to coat a substrate. It is understood that the magnet arrangement can be realized in various ways. 3A exemplifies a magnet arrangement 300 , wherein the magnet arrangement 300 a carrier 304 and a plurality of magnets, wherein the plurality of magnets along a longitudinal extent 301 the magnet arrangement 300 in rows 302a . 302b . 302c can be arranged. In 3B and 3C is in each case by way of example a cross section or a side view of the magnet arrangement 300 illustrates, for. In 3B a magnet arrangement 300 for a magnetron with a planar target (for a planar magnetron) and in 3C for a magnetron with tubular target 308 (for a tube magnetron). According to various embodiments, the multiple magnets 302 the magnet arrangement 300 on or on the carrier 304 attached. In the 3A shown magnet arrangement 300 shows, for example, the magnets that generate the linear area of the race track. According to various embodiments, the magnet assembly 300 additional magnets (eg, along a curved path) that create the curved portions of the race track. According to various embodiments, the two outer rows 302a . 302c be interconnected by means of several additional magnets along a curved path or be. It can be the two outer rows 302a . 302c have the same polarity and the inner row 302b an opposite polarity.

According to various embodiments, the plurality of magnets of the magnet assembly 300 each disposed at a predefined distance on the carrier, wherein this distance for each magnet of the plurality of magnets of the magnet assembly 300 can be adjusted, for. By placing a spacer (eg, a non-magnetic plate of a predefined thickness) between each of the magnet and the carrier 304 is arranged. Generally, the geometric position (position, distance, and / or orientation) of the magnets relative to the carrier 304 be predefined. Furthermore, the carrier can 304 have a predefined shape, which at least partially the relative position to each other and / or the orientation of the plurality of magnets of the magnet assembly 300 pretends. The (eg detachable) fixing of the magnets to the carrier 304 can be done in a variety of ways, for example, the carrier 304 even be magnetic, z. As iron, so that the magnets due to the magnetic force on or on the carrier 304 be liable.

According to various embodiments, the magnet assembly 300 further relative to a target 320 (a cathode) may be arranged, for. B. with a predefined position (position, distance, and / or orientation), such as in the 3D and 3E is illustrated.

According to various embodiments, the magnets of the first row 302a and the magnets of the third row 302c in each case on the carrier 304 be arranged or that the north pole (or south pole) of the carrier 304 directed away, with the magnets of the second row 302b of magnets then on the support 304 are arranged that their south pole (or north pole) of the carrier 304 is directed away. Illustratively, the plurality of magnets of the magnet arrangement 300 in rows 302a . 302b . 302c be arranged with a north-south-north or south-north-south orientation.

3D illustrates, for example, the location of the magnet assembly 300 relative to a planar target of a magnetron assembly in a schematic cross-sectional view or side view. The target can be a surface to be atomized 320a have, wherein the magnet arrangement 300 on the back side 320b of the target 320 (opposite to the surface to be atomized 320a ) can be arranged. Furthermore, the magnet arrangement 300 at a predefined distance or in direct contact with the target 320 be arranged. Furthermore, the magnet arrangement 300 parallel to the surface to be atomized 320a of the target 320 or at an angle 311 to the surface to be atomized 320a of the target 320 be arranged. According to various embodiments, the arrangement of the plurality of magnets of the magnet arrangement 300 relative to the target 320 (or the surface to be atomized 320a of the target 320 ), wherein the plurality of magnets, as described above, in a suitable manner on the carrier 304 can be attached (arranged).

As in 3E is illustrated in a schematic cross-sectional view, the magnet assembly 300 in an analogous way also within 320i a tubular target 320 be arranged, the outer surface 320a of the tubular target 320 the surface to be atomized 320a of the target 320 can be.

According to various embodiments, the angle 311 between the magnet assembly 300 or the plurality of magnets of the magnet arrangement 300 and the surface to be atomized 320a of the target 320 be selected (defined) in consideration of the temperature gradient during operation of the magnetron.

As in 4 exemplified, several magnets 302 the magnet arrangement 300 along one direction 301 be arranged, for. B. side by side or in a row on the carrier 304 , Thereby the magnets can 302 directly adjacent to each other or alternatively be arranged at a distance from each other, so that there is a gap between each adjacent magnet 302 extends.

According to various embodiments, when operating a magnetron with the magnet assembly 300 a temperature profile 400t (a spatial temperature distribution 400t ) along the direction 301 which, in the simplest case, is linear in direction 301 increases. For example, a first magnet 402a the multiple magnets 302 when operating the magnetron a first Have temperature T _a and a second magnet 402b the multiple magnets 302 can have a second temperature T _b when operating the magnetron, wherein T _a and T _{b is} a temperature difference or (based on the spatial arrangement of the magnets 402a . 402b ) can define a temperature gradient.

According to various embodiments, the magnets 302 the magnet arrangement 300 be adapted such that this temperature gradient, which for example due to the cooling water flow and / or in the target or in the magnet assembly 300 registered heat output can occur, can be compensated.

According to various embodiments, the magnetization 400m the magnets 302 be adapted, for. B. stepwise between a first magnetization M _a for the first magnet 402a and a second magnetization M _b for the second magnet 402b ,

In an analogous way, the magnetization 400m the magnets 302 adapted to any temperature profile (or depending on the width of the magnets along the direction 301 gradually approximated).

Adjusting the magnetization M of the magnets 302 For example, it may cause only the strength of the generated magnetic field to be changed and not the geometry of the generated magnetic field, which may, for example, affect the shape and / or position of the race track.

According to various embodiments, the second magnet 402b , which in operation has a higher temperature T _b than the first magnet 402a (With the temperature T _a ), be set up so that this when setting up the magnet assembly 300 at room temperature has a greater magnetization M _b than the first magnet 402a (with the magnetization M _a ). When operating the magnetron with the magnet assembly 300 Consequently, the higher magnetization T _b due to the higher operating temperature T _{b can be} compensated, so that the spatial distribution of the means of the magnet assembly 300 generated magnetic field during operation of the magnetron over the surface to be atomized 320a of the target is homogeneous or deviates as little as possible from an assigned spatial magnetic field distribution.

According to various embodiments, the plurality of magnets 302 the magnet arrangement 300 create the elongated (eg, linear) part (or, for example, the parallel, longitudinal parts) of the race track.

As with the previous one 3A to 3E and 4 described, the spatial temperature distribution 400t be determined and when adjusting (eg, during calibration or manufacture) of the magnet assembly 300 be taken into account. In this case, it is possible to determine a first temperature T _a which, when the magnetron is operated, is established in a first region of the magnet arrangement and / or the cathode (for example, in the region in which the first magnet is located 402a is arranged during operation of the magnetron), and a second temperature T _b can be determined, which is established during operation of the magnetron in a second area of the magnet arrangement and / or the cathode (eg in the area in which the second one magnet 402b when operating the magnetron), wherein the first region is at a distance from the second region and wherein the first temperature T _a is different from the second temperature T _b .

According to various embodiments, the two different temperatures T _a , T _{b may} define a temperature difference, further due to the location of the magnets 402a . 402b a temperature gradient can be defined.

Clearly, a spatial temperature distribution or a temperature gradient (for example along a line or a trajectory) can be determined, which or which is present when the magnetron is operated in the target, in the cooling water and / or in the magnet 302 the magnet arrangement 300 established.

According to various embodiments, the plurality of magnets of the magnet assembly 300 be adapted to compensate for the temperature gradient or the spatial temperature distribution, for example, such that the means of the magnets 302 the magnet arrangement 300 generated magnetic field over the surface of the cathode to be atomized 320 having a corresponding temperature gradient rectified magnetic field gradients. The temperature profile can be continuous and the magnetization of the magnets 302 can change gradually (discretely).

According to various embodiments, the magnet assembly 300 to the temperature profile 400t be adapted by magnetizing at least one magnet of the plurality of magnets 302 is changed. Furthermore, the magnet arrangement 300 to the temperature profile 400t be adjusted by the position (position and / or orientation) of at least one magnet of the multiple magnets 302 relative to the surface 320a the cathode 320 is changed. Optionally, the position of the carrier 304 the multiple magnets 302 relative to the surface 320a the cathode 320 to be changed.

Adjusting the magnet assembly 300 taking into account the temperature profile 400t can be done, for example, that in each case in a region of the magnet assembly 300 in which a smaller or greater temperature sets during operation of the magnetron, a magnet is arranged with a smaller or larger magnetization than in another area of the magnet arrangement 300 ,

Adjusting the magnet assembly 300 taking into account the temperature profile 400t This can be done, for example, by a magnet with a greater or smaller distance from the surface in each case in a region of the magnet arrangement in which a smaller or greater temperature is established during operation of the magnetron 320a the cathode 320 is provided as in another area of the magnet assembly.

As in 3D and 3E illustrated, the adaptation of the magnet arrangement 300 be done by the entire magnet assembly 300 (Carrier 304 and the magnets) relative to the surface 320a the cathode 320 be tilted. In this case, the tilt angle may depend on the magnitude of the temperature gradient, wherein the tilting takes place in such a way that warmer areas of the magnet arrangement 300 closer to the surface 320a the cathode 320 lie.

As described above, a magnetron device can be a carrier 304 have, where magnets 302 (eg in rows 302a . 302b . 302c ) can be arranged on the carrier. The magnets 302 can be set up and relative to each other along one direction 301 be arranged that a magnetic field 306 over one relative to the carrier 304 arranged cathode surface 320a a magnetron cathode 320 can be provided. To compensate for a different heating of the magnets 302 when operating the magnetron or the magnetron cathode 320 can use the multiple magnets 302 different magnetizations from each other 400m have, so that by means of the plurality of magnets 302 generated magnetic field 306 along the direction 301 rises or falls.

In this case, the carrier 304 a spatial extent along a longitudinal direction 301 in a range of about 1 m to about 5 m. As in 4 illustrates, the respective magnetization 400m the multiple magnets 302 along the longitudinal direction 301 of the carrier 304 rise, in which case the magnet arrangement 300 should be positioned and / or aligned relative to a cathode so that the magnets 402b with a higher magnetization Mb heat more during operation of the magnetron, than magnets 402a with a lower magnetization Ma.

Because the magnetization of the magnets 302 Depending on the temperature, the magnetization of the magnets at room temperature can be taken into account when adjusting the magnets, wherein the temperature dependence of the magnetization of the magnets is taken into account by correspondingly adjusting the strength of the magnetization of the magnets at room temperature.

According to various embodiments, the respective magnetization 400m the multiple magnets 302 between two areas of the magnet arrangement 300 increase or decrease from a baseline by more than about 0.01 per Kelvin of the detected temperature difference between the two regions. According to various embodiments, the respective magnetization 400m the multiple magnets 302 between two areas of the magnet arrangement 300 increase or decrease from a baseline by more than about 0.02 per Kelvin of the detected temperature difference between the two regions. According to various embodiments, the respective magnetization 400m the multiple magnets 302 between two areas of the magnet arrangement 300 increase or decrease from a baseline by more than about 0.03% per Kelvin of the detected temperature difference between the two regions. According to various embodiments, the respective magnetization 400m the multiple magnets 302 between two areas of the magnet arrangement 300 increase or decrease from a baseline by more than about 0.05% per Kelvin of the detected temperature difference between the two regions. According to various embodiments, the respective magnetization 400m the multiple magnets 302 between two areas of the magnet arrangement 300 increase or decrease from a baseline by more than about 0.1% per Kelvin of the detected temperature difference between the two regions.

According to various embodiments, the increase in the magnetization of the magnets 302 (based on the room temperature) for a respective temperature difference substantially compensate for the temperature coefficient of the magnetization.

According to various embodiments, the basic value of the magnetization of the magnets 302 (based on the room temperature) in a range of about 1 mT to about 1 T, z. In a range of about 50 mT to about 500 mT.

According to various embodiments, in reactive sputtering, the magnetron may be adjusted based on the determined temperature profile, as in a reactive magnetron sputtering process conventional calibration of the magnet assembly may be unsuitable due to, for example, local power control by means of the gas supply (or other local influences).

According to various embodiments, a homogeneous magnetic field along the longitudinal direction 301 a magnet arrangement 300 be provided during operation of the magnetron in that the magnet assembly 300 of the magnetron is provided inhomogeneously (with a gradient) at room temperature or a constant ambient temperature, the term being able to refer homogeneously to the fact that the local spatial distribution of the magnetic field (eg in a plane transverse to the longitudinal direction 301 ) along the longitudinal direction 301 remains essentially the same.

According to various embodiments, it may be necessary to keep a reactive sputtering process stable by means of at least one control, so that due to the control influences can be covered, which for adapting the magnet arrangement 300 could be used, for. For example, due to the complexity of the reactive sputtering process (eg due to effects such as the CCE "Cross Corner Effect" or the CME "Cross Magnetron Effect"), the spatial distribution of the layer properties can not allow conclusions as to whether and how the magnet arrangement 300 to be adapted to a magnetron.

According to various embodiments, multiple magnets 302 (For example, three, four, five, six, seven, eight, nine, ten, or more than ten magnets or more than 20 magnets), each with different magnetization such along a direction 301 of the carrier 304 be arranged so that their magnetization in each case monotonically (or strictly monotone) along the direction becomes larger (increases). Further, the plurality of magnets each having different magnetization may be arranged in a row, respectively, and two of the plurality of magnets each having different magnetization may be adjacent to each other or adjacent to each other.

5 illustrates a magnet assembly 500 in a schematic view, wherein the magnet arrangement 500 The following may comprise: a carrier 304 , several on the carrier 304 arranged magnets, wherein the plurality of magnets on the support 304 can be arranged, that a magnetic field over a relative to the carrier 304 arranged cathode surface of a cathode can be provided. It can be a first set 302b of the plurality of magnets along a first direction 301 be arranged. Furthermore, a second quantity 302a of the plurality of magnets along a second direction 301 be arranged, the second direction 302a at an angle 501 to the first direction 301 runs. The magnet arrangement 500 can be a magnetron arrangement 500 or part of a magnetron arrangement 500 be, z. B. can the magnet assembly 500 be arranged on a planar target or in a tubular target.

Furthermore, a third quantity 302c of the plurality of magnets along a third direction 301c be arranged, the third direction 301c at an angle 501c to the first direction 301 runs. Furthermore, a third quantity 302c of the plurality of magnets along a third direction 301c be arranged, the third direction 301c at an angle to the second direction 301 runs.

According to various embodiments, the first angle 501 between the first direction 301 and the second direction 301 in a range of about 0.05 ° to about 10 °. According to various embodiments, the second angle 501c between the first direction 301 and the third direction 301c in a range of about 0.05 ° to about 10 °. According to various embodiments, the magnets may be so on the carrier 304 be arranged that the first angle 501 equal to the second angle 501c is.

According to various embodiments, the magnets may be so on the carrier 304 be arranged that the three directions 301 . 301 . 301c lying in a plane, z. B. in a magnet arrangement 500 for a planar magnetron. Furthermore, the magnets can be so on the support 304 be arranged that the three directions 301 . 301 . 301c not in a common plane, e.g. B. in a magnet arrangement 500 for a tubular magnetron.

Illustratively, the magnets in a magnet arrangement 500 for a tubular magnetron on the support 304 be arranged that, in a sectional plane transverse to the direction 301 , a first vector of the respective magnet of the first set 302b to the respective magnet of the second set 302a and a second vector of the respective magnet of the first set 302b to the respective magnet of the third set 302c form an opening angle (eg smaller than 180 °). In this case, the opening angle along the direction 301 change, z. B. become larger or smaller.

According to various embodiments, the distance may be measured in a plane perpendicular to the direction 301 , between the magnets of the first set 302b and the second lot 302a and / or the first quantity 302b and the third lot 302c along the direction 301 change (see, for example 3B showing a section of a magnetron arrangement perpendicular to the direction 301 illustrates or example 3C showing a section of a magnetron arrangement perpendicular to the direction 301 illustrated).

Illustratively, a magnetic field gradient along the direction 301 are generated by the three rows of magnets are not aligned parallel to each other, but in one direction (transverse to the direction 301 ) can be opened slightly (eg, the outer rows can be over the length 301 continue to diverge). Thus, the effective field at the target surface can be weaker, for example, the two race-track lines are no longer exactly parallel to each other.

According to various embodiments, the temperatures (eg, the first temperature and the second temperature) T _a , T _{b may} be determined by measuring the temperature of the cooling water. T _a can be determined for example by measuring the flow temperature and T _b can be determined for example by means of measuring the return temperature. Thus, for example, a temperature gradient can be determined based on the measurements of the flow temperature and the return temperature.

Claims (8)

A method of setting up a magnet assembly of a magnetron, the method comprising: Determining a spatial temperature distribution, which occurs for the magnet arrangement and / or the cathode during operation of the magnetron, • Adapting a plurality of magnets of the magnet arrangement in consideration of the spatial temperature distribution, so that a spatial magnetic field distribution, which takes into account the spatial temperature distribution, is provided over a surface of the cathode. The method of claim 1, wherein determining the spatial temperature distribution comprises: Determining a first temperature which is established during operation of the magnetron in a first region of the magnet arrangement and / or the cathode, and Determining a second temperature which occurs during operation of the magnetron in a second region of the magnet arrangement and / or the cathode, wherein the first region is at a distance from the second region and wherein the first temperature is different from the second temperature. The method of claim 1 or 2, wherein determining the spatial temperature distribution comprises determining a temperature gradient. Method according to one of claims 1 to 3, wherein for balancing a temperature gradient of the spatial temperature distribution, the adaptation of the magnet arrangement is such that the magnetic field generated by the magnet arrangement has a corresponding temperature gradient to the temperature gradient over the surface of the cathode. Method according to one of claims 1 to 4, wherein adjusting the plurality of magnets comprises: For at least one of the plurality of magnets, changing the magnetization thereof; and or For at least one of the plurality of magnets, changing its position and / or orientation relative to a surface of the cathode. Method according to one of claims 1 to 5, wherein the adaptation is carried out in that in each case in a first region of the magnet arrangement, in which a larger temperature sets during operation of the magnetron, a magnet is arranged with a larger magnetization, as in a second region the magnet assembly in which sets a lower temperature during operation of the magnetron. Method according to one of claims 1 to 6, wherein the adaptation is carried out in that in each case in a first region of the magnet arrangement, in which a larger temperature sets during operation of the magnetron, a magnet is provided with a smaller distance to the surface of the cathode, as in a second region of the magnet arrangement, in which sets a lower temperature during operation of the magnetron. A method according to any one of claims 1 to 7, wherein the fitting is performed by tilting the entire magnet assembly relative to the surface of the cathode.

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