Vacuum processing apparatus and method for vacuum plasma processing at least one substrate or for manufacturing a substrate

Abstract

In the vacuum process receptacle (3), a plasma is generated between a first plasma electrode (111) and a second plasma electrode (112) in order to carry out a vacuum plasma process on a substrate (9). In order to minimize the burying of at least one of the two plasma electrodes (111, 112) by deposited material resulting from the process, the electrode (111) is provided with a surface pattern of plasma-electrode-inactive regions (30NPL) and a surface pattern of plasma-electrode-active regions (30PL). The current path between the two electrodes (111, 112) is concentrated on the different plasma-electrode-active regions (30PL), resulting in a continuous sputter cleaning of these regions (30PL).

Description

[0001] The invention belongs to the technical field of processing a substrate in a vacuum by means of a plasma established between two plasma electrodes, by which processing a material is generated in a reaction space exposed to the plasma electrodes, which material is deposited on at least one of the plasma electrodes and can cause process instabilities.

[0002] It is an object of the invention to eventually reduce drifts of such a substrate processing process over time, including long-time drifts, i.e. drifts between maintenance intervals of the processing apparatus.

[0003] This is achieved by a vacuum plasma processing apparatus comprising at least one first plasma electrode and at least one second plasma electrode within a vacuum receiver for generating a plasma therebetween.

[0004] The first and second plasma electrodes are connectable to an electrical plasma supply arrangement establishing a first electrical potential to the first plasma electrode and a second electrical potential to the second plasma electrode, whereby both the first and second electrical potentials are independently variable with respect to a system ground potential, e.g. as applied to the walls of the vacuum receiver.

[0005] The at least first plasma electrode comprises an electrode body having an outer patterned surface, the surface comprising a first surface area which contributes nothing to the plasma electrode effect and is a metallic material or a dielectric material, and a second surface area which is plasma electrode effective and is a metallic material or a surface of a dielectric material layer deposited on a metallic material, the metallic material being operated at the first electrical potential.

[0006] Definitions:

[0007] • Throughout the description and claims, by "substrate" we understand a single workpiece or a batch of workpieces typically processed in a reaction space. The workpieces can be of any shape and material, however especially plate-like, flat or curved;

[0008] • Whenever a plasma supply arrangement, which can comprise one or more electrical generators, generates a potential difference, a plasma discharge voltage, a spectrum thereof including a DC component, between the first plasma electrode and the second plasma electrode, then depending on the polarity of the DC component one electrode is the anode and the other electrode is the cathode. In this case, as described throughout the description and claims, the "first plasma electrode" is the anode;

[0009] • Whenever there is no DC component in the spectrum, one can not be able to identify the plasma electrodes as anodes or cathodes. In these cases, the first plasma electrode refers to the plasma electrode that is not consumed by the substrate treatment. Thus, for example, in order to perform sputter deposition of a layer on a substrate or in order to etch a substrate, the target electrode or the substrate on the substrate carrier is consumed as a plasma electrode, and the "first plasma electrode" refers to the electrode that is not the target electrode or on which no substrate to be etched is residing;

[0010] • Whenever the spectrum has no DC component and no plasma electrode is consumed for the substrate treatment (e.g. in a plasma-enhanced CVD), then the first plasma electrode refers to one of the plasma electrodes, and even the second plasma electrode can be constructed according to the features described and claimed for the first plasma electrode;

[0011] • The term "metallic material" we understand as any material that comprises a metal having an electrical conductivity equal or similar to the electrical conductivity of a metallic material, but the material also comprises for example graphite, a conductive polymer, a semiconductor material or a respectively doped material;

[0012] • The "surface area not contributing to the plasma electrode effect" of a plasma electrode surface area we understand as explicitly provided for the purpose of not contributing to the electrode effect. Thus, and by way of example, an opening in the surface of an electrode body for feeding a gas into the vacuum recipient explicitly has the purpose of feeding a gas, and even if the surface area of such an opening does not contribute to the plasma electrode effect, it is not considered a "surface area not contributing to the plasma electrode effect"; the "surface area not contributing to the plasma electrode effect" carries a significantly smaller, practically negligible fraction of the current flowing between the two plasma electrodes and along the plasma, which is concentrated on the "plasma electrode effective surface area" defined below;

[0013] • The surface area of the "plasma electrode effective surface area" we understand as being appropriately supplied with power, resulting in a plasma burning between the second electrode and such surface area. The current flowing between the two plasma electrodes and along the plasma is exactly concentrated on these different "plasma electrode effective surface areas";

[0014] • The "new state" of an electrode we understand as an electrode that has not yet been influenced by a plasma treatment process.

[0015] It is known that both plasma electrodes are subject to sputtering as well as material deposition. Which of these two processes is the dominant process at one of the plasma electrodes under consideration depends on the purpose of this electrode within the plasma process. If one of these processes is dominant, then net sputtering or net deposition results.

[0016] For example, for sputter deposition, the purpose of the target plasma electrode is predominantly sputtering. However, some material deposition also occurs on the target, which is known in the context as target poisoning. The plasma electrode opposite the target electrode is predominantly subject to material deposition, which leads to the so-called "buried" electrode or "vanishing" electrode or "vanish" electrode or anode.

[0017] If such a counter-plasma electrode has a metallic material surface, then any growth deposition of a material on it whose electrical conductivity is lower than that of the metallic material of the surface in the new state would destabilize the process.

[0018] If the plasma is provided by Rf, then the surface of one or even both of the plasma electrodes can be a dielectric material, so that the Rf supply signal is capacitively coupled to the plasma. In these cases, too, an increase in the deposit of the dielectric material on the dielectric surface plasma electrode in the new state would also lead to destabilization of the process.

[0019] The inventors have realized that, since the body of the first plasma electrode has a first surface area - NPL - which contributes nothing to the plasma electrode effect and a surface area - PL - which is patterned in the plasma electrode effective surface, it can be said that the plasma which provides the electric field and thus the current path between the first and second plasma electrodes is to be focused or concentrated on the PL surface area, which leads to the fact that only NPL is predominantly or even exclusively subject to deposition of material, while at the PL surface area the surface material exposed to the plasma remains essentially unaffected, i.e. without material deposits.

[0020] In the context of the different embodiments of the electrode body described below, details about the process along the surface of the electrode body according to the invention will also become apparent to the person skilled in the art.

[0021] In one embodiment of the vacuum plasma processing apparatus according to the invention, in the new state of at least the first plasma electrode, and in the projection of the pattern on the envelope trajectory of the body, the ratio Q of the sum of the projected areas of the second surface areas - PL - of the pattern to the sum of the projected areas of the first surface - NPL - areas is

[0022] 0.1 ≤ Q ≤ 9.

[0023] This corresponds to a ratio range of about 10% to about 90% of the projected surface area PL to (PL + NPL).

[0024] In one today successfully practiced embodiment of the vacuum plasma treatment apparatus according to the present invention, in the new state of the at least first plasma electrode, and in the projection of the pattern on the envelope trajectory of the body, the ratio Q of the sum of the projected areas of the second surface areas - PL - of the pattern to the sum of the projected areas of the first surface areas - NPL - is

[0025] 0.4 ≤ Q ≤ 1.

[0026] This corresponds to a ratio range of about 30% to about 50% of the projected surface area PL to (PL + NPL).

[0027] In one embodiment of the vacuum plasma treatment apparatus, in the new state of the at least first plasma electrode, at least some of the second surface areas - PL - and at least some of the first surface areas - NPL - are metal material surface areas.

[0028] In this embodiment, the first - NPL - surface areas limit a space, where due to the geometry, the plasma can not burn.

[0029] In one embodiment of the vacuum plasma treatment apparatus, in the new state of the at least first plasma electrode, at least some of the first surface areas - NPL - are dielectric material surface areas, and at least some of the second surface areas - PL - are metal material surface areas.

[0030] Also in this embodiment, the dielectric material of the first surface areas - NPL - causes the electric field and current path to concentrate on the second - PL - surface areas.

[0031] In one embodiment of the vacuum plasma treatment apparatus according to the present invention, in the new state of the at least first plasma electrode, at least some of the first surface areas - NPL - and at least some of the second surface areas - PL - are dielectric material surface areas.

[0032] This embodiment is suitable for Rf plasma supply, where the dielectric constant and thickness of the respective dielectric material control the resulting impedance.

[0033] In one embodiment of the vacuum plasma treatment apparatus according to the present invention, the body comprises a core and an envelope, and the pattern of the patterned surface is defined by the envelope.

[0034] The cladding can thus carry a pattern of first surface areas - NPL - and second surface areas - PL - or indeed as a grid, forming first or second surface areas, leaving second or first surface areas, respectively, freely accessible on the surface of the core.

[0035] Such a cladding can be a maintenance replacement part.

[0036] In one embodiment of the vacuum plasma processing apparatus according to the invention, in the new state of at least the first plasma electrode, the second surface areas - PL - are of a metallic material, and the vacuum plasma apparatus is configured to generate, in operation, in the space exposed to the vacuum recipient of at least the first plasma electrode, a material whose electrical conductivity is less than the metallic material of the second surface areas - PL -.

[0037] Although the electrode body can in fact have any suitable shape, in one embodiment of the apparatus according to the invention, the electrode body extends along a straight axis, which facilitates integration into the overall apparatus. Furthermore, by implementing an electrode body along a straight axis, the fact that the first electrode according to the invention is highly localized in the vacuum recipient can be enhanced. Please note that due to the fact that usually the walls of the vacuum recipient are used as first electrodes operating at the system ground potential, common prior art implementations of first electrodes are also very indeterminate with respect to localization in the vacuum recipient.

[0038] In one embodiment of the vacuum plasma processing apparatus according to the invention, the electrode body is surrounded by a geometric trajectory body having an elliptical or circular or polygonal cross section.

[0039] In one embodiment of the vacuum plasma processing apparatus according to the invention, the electrode body is surrounded by a geometric trajectory body which, considered in one direction, can have a tapering cross-sectional profile.

[0040] Thereby, the distribution of material deposition effects and material sputtering effects along the body of the first plasma electrode can be adjusted, in particular accurately homogenized.

[0041] In one embodiment of the vacuum plasma processing apparatus according to the invention,

[0042] The first surface areas - NPL - of the patterned surface comprise at least one of:

[0043] - a void recess having a surface of a metallic material;

[0044] - a void recess having a surface of a metallic material covered by a layer of a dielectric material;

[0045] - a recess having a surface of a metallic material and filled with a dielectric material.

[0046] As mentioned above, it is well known to the person skilled in the art or in the profession that recesses in the surface of a metallic material exposed to a plasma can be filled with plasma or can be free of plasma, depending on the size of these recesses. Thus, it is an embodiment of the realization of the electrode body to provide recesses in the surface of the metallic material which are tailored to prevent the occurrence of a plasma therein. As is known in the art, this is achieved in the course of the tailoring of the respective device by taking into account the dominant dark space distance, also referred to as "plasma sheath" distance. Without plasma, the electrical conductance in the recesses is relatively small and only a weak ion acceleration potential gradient exists in the recesses, which is not sufficient to predominantly sputter the surface in the recesses: material outside the reaction space is only deposited in the recesses, leading to the formation of a growth layer in the recesses of this material, which can be less conductive than the metallic material on which such a layer is deposited.

[0047] In other words, in the case that the conductivity of the material generated by the respective process, e.g. by reactive magnetron sputtering or by etching, is lower than the metallic material, the overall metallic material surface of the first electrode body is reduced and the electric field is focused on the remaining metallic material surface next to the recesses and exposed to the plasma, i.e. on the second surface area -PL- of the pattern. As a result, the potential gradient across the plasma sheath is increased, the ion acceleration towards the metallic material surface of the second surface area -PL- is increased and thus the clean sputtering or etching of these metallic material surfaces next to the recesses is increased. Along the remaining metallic material area of the electrode body and thus the second surface area -PL- remains clean of deposits, which leads to a stable electrode effect of the electrode body and thus of the process.

[0048] As mentioned above, the growth of a layer of material with a relatively low electrical conductivity in the recesses only can still lead to a process drift. Thus, and in an embodiment, instead of or in addition to providing void recesses as the first surface area -NPL-, at least some of the first surface area -NPL- is realized by voids in the metallic material which are covered by a layer of dielectric material, e.g. a ceramic material. Thereby, the electrode effect of the body becomes stable from the beginning of the plasma process, the second surface area -PL- of the metallic material remains clean from the beginning of the plasma treatment.

[0049] Instead of or in addition to providing void recesses in the metallic material, and / or providing void recesses in the metallic material covered by a layer of dielectric material, further embodiments also provide recesses in the metallic material, but filled with a dielectric material, e.g. with a ceramic material.

[0050] Instead of providing voids in the surface of the metal material of the body or in the surface of a metal material cladding thereof and then filling or coating such recesses with a dielectric material, the metal material surface can be provided with a surface pattern of regions of dielectric material on the metal material which provide the first surface region -NPL-.

[0051] If the first electrode is a plasma electrode for Rf plasma, the second surface region -PL- of the pattern can also be made of a dielectric material. In this case, the dielectric material pattern of the second surface region -PL- on the metal material is made thinner than the dielectric material pattern of the first surface region -NPL- on the metal material and thus exhibits a higher capacitive coupling to the plasma than the first surface region -NPL- and / or the dielectric constant of the dielectric material of the second surface region is greater than the dielectric constant of the dielectric material of the first surface region.

[0052] As will be completely obvious to the person skilled in the art, there are a large number of possibilities to realize the electrode body according to the invention.

[0053] In one embodiment of the vacuum plasma treatment apparatus according to the invention, the electrode body extends along an axis and the first surface region -NPL- comprises at least one groove around the axis.

[0054] Thereby, and in one embodiment of the vacuum plasma treatment apparatus according to the invention, the at least one groove is a helical groove or an annular groove.

[0055] In one embodiment of the vacuum plasma treatment apparatus according to the invention, the second surface region -PL- comprises at least one helical region around the axis of the body. Such a helical region can be a region of metal material coated on a core of dielectric material or on a cladding of the body.

[0056] As just mentioned, in one embodiment of the vacuum plasma treatment apparatus according to the invention, the helical region of the second surface region -PL- is a wire of metal material.

[0057] As in the just mentioned embodiment of the vacuum plasma treatment apparatus, the wire is self-standing, except for a rigid power supply connection to the wire.

[0058] In one embodiment of the vacuum plasma treatment apparatus according to the invention, the first surface region -NPL- comprises gaps between protruding webs.

[0059] In one embodiment of the vacuum plasma treatment apparatus according to the invention, the first surface region -NPL- comprises at least one gap between mutually spaced apart metal material plates.

[0060] In one embodiment of the vacuum plasma processing apparatus according to the present invention, the first surface area -NPL- comprises at least one dielectric material plate sandwiched between metal material plates.

[0061] This results in a multi-layer sandwich structure of the metal plate on the first potential and the dielectric material sandwich plate.

[0062] In one embodiment of the vacuum plasma processing apparatus according to the present invention, the body of the first plasma electrode is cooled.

[0063] Thereby and in one embodiment of the plasma processing apparatus according to the present invention, the body comprises a channel arrangement for a cooling medium or is mounted to a heat sink.

[0064] One embodiment of the plasma processing apparatus according to the present invention comprises an impedance element interconnected between the metal material portion of the body of the first plasma electrode and a metal material portion of the apparatus, which operates on a reference potential, such as a system ground potential.

[0065] Such an impedance element can be one or more than one discrete and interconnected passive impedance element and / or one or more than one active impedance element, such as a FET, which is thereby also controllable in order to adjust the overall dominant impedance before or during plasma operation. By adjusting the impedance element, the self-cleaning effect of the second surface area -PL- can be adjusted.

[0066] One embodiment of the plasma processing apparatus according to the present invention comprises a negative feedback control loop for controlling at least one of the first potential, the second potential, the potential difference.

[0067] One embodiment of the plasma processing apparatus according to the present invention comprises a negative feedback control loop, wherein the measured dominant entity consists of the first potential to be negatively feedback controlled and the apparatus comprises a sensing element for the first potential relative to a reference potential.

[0068] One embodiment of the plasma processing apparatus according to the present invention comprises a negative feedback control loop, wherein the measured dominant entity consists of or comprises the first potential relative to a reference potential and the plasma processing apparatus comprises a sensing element for the first potential relative to a reference potential, the adjusting entity in the negative feedback control loop consists of or comprises at least one of the reactive gas flow and the potential difference between the first plasma electrode and the second plasma electrode, and the apparatus comprises at least one of an adjustable flow controller for the reactive gas into the vacuum receiver and an adjustable plasma supply arrangement for the potential difference.

[0069] Note that the measured dominant entity can for example be a function of the first potential, possibly a multivariate function, and the regulating entity can comprise additional physical entities, for example the pressure in the vacuum receiver.

[0070] Thus, as an example, the dominant voltage of the first plasma electrode relative to for example the system ground potential is measured, and this voltage or a function thereof, possibly a multivariate function thereof, is compared to a desired preset value of this voltage, or a desired preset function thereof, and the flow of reactive gas into the vacuum receiver and / or the voltage or current between the two plasma electrodes is adjusted to render the dominant value of the measured dominant voltage or function thereof to the desired preset value of the voltage or function thereof with a minimum difference. Typically, the preset value can be a constant value, or can vary over time in a preset manner.

[0071] For the potential difference between the two plasma electrodes, providing a negative feedback control loop as described above for at least one of the potentials can be considered an invention in itself.

[0072] In one embodiment of the plasma processing apparatus according to the invention, the first plasma electrode is enclosed in a housing in the vacuum receiver, the housing being remote from and electrically isolated from the first plasma electrode, and having at least one opening exposed to the reaction space in the vacuum receiver and tailored to allow the plasma to establish between the first plasma electrode and the second plasma electrode through said opening.

[0073] In one embodiment of the plasma processing apparatus according to the invention, the housing is cooled.

[0074] In one embodiment of the vacuum plasma processing apparatus according to the invention, the housing comprises a channel arrangement for a cooling medium or is mounted to a heat sink.

[0075] In one embodiment of the vacuum plasma processing apparatus according to the invention, at least a portion of the housing is of a metallic material and electrically operated in a floating manner or electrically connected to a reference potential such as the system ground potential.

[0076] In one embodiment of the vacuum plasma processing apparatus according to the invention, at least a portion of the housing is of a dielectric material.

[0077] In one of the just described embodiments of the vacuum plasma processing apparatus according to the invention, the opening is in the portion of the dielectric material.

[0078] In one embodiment of the vacuum plasma treatment apparatus according to the present application, at least a portion of the housing, in particular the portion having the opening, is a maintenance replacement part, or the housing comprises a shield as maintenance replacement part at least along a major portion of its inner surface.

[0079] In one embodiment of the vacuum plasma treatment apparatus according to the present application, the housing comprises a shield of a metallic material at least along a major portion of its inner surface, which shield is electrically operated in a floating manner or connected to a reference potential, such as a system ground potential.

[0080] One embodiment of the vacuum plasma treatment apparatus according to the present application comprises a working gas inlet, which is discharged in the housing, which inlet is connectable or connected to a working gas reservoir.

[0081] In one embodiment of the vacuum plasma treatment apparatus according to the present application, the vacuum receiver comprises a working gas inlet, which is connectable or connected to a working gas reservoir, and consists of a working gas inlet discharged in the housing.

[0082] In one embodiment of the vacuum plasma treatment apparatus according to the present application, the body of the first plasma electrode is hidden from the line of sight from the substrate carrier. Thereby, deposition of material sputtered off from the first plasma electrode is prevented from depositing on the substrate.

[0083] In one embodiment of the vacuum plasma treatment apparatus according to the present application, the body is hidden from the line of sight from the substrate carrier by means of the housing or by means of a fixed or adjustable shutter across the opening of the housing.

[0084] In one embodiment of the vacuum plasma treatment apparatus according to the present application, the shutter is of a metallic material and electrically operated in an electrically floating manner or electrically operated on a reference potential with respect to a system ground potential.

[0085] In one embodiment of the vacuum plasma treatment apparatus according to the present application, the shutter is of a dielectric material.

[0086] It has to be noted that the positioning of the first plasma electrode within the housing, in particular if configured along a straight axis, can be adjustable, in particular in the direction of the axis, and the first plasma electrode can even be removed and reintroduced into the housing in order to optimize the plasma ignition, or more generally to adjust the current path between the first plasma electrode and the second plasma electrode.

[0087] In one embodiment of the vacuum plasma treatment apparatus according to the present invention, the second plasma electrode is configured according to the first plasma electrode. However, the first plasma electrode and the second plasma electrode need not be configured identically. This can be practiced if either of the first plasma electrode and the second plasma electrode does not substantially contribute to the material deposited on the substrate according to their purpose, for example, in a PECVD process.

[0088] In one embodiment of the vacuum plasma treatment apparatus according to the present invention, the second plasma electrode is a target or a target holder of a magnetron sputter source, or a substrate holder or a substrate of a plasma etching source having a source anode consisting of the first plasma electrode.

[0089] Thus, at such a magnetron sputter source or etching source, the source "anode" that is usually provided is omitted, which simplifies the source.

[0090] In one embodiment of the vacuum plasma treatment apparatus according to the present invention, the second plasma electrode is a target of a magnetron sputter source, the target being silicon.

[0091] In one embodiment of the vacuum plasma treatment apparatus according to the present invention, the vacuum receiver comprises a reactive gas inlet connectable or connected to a reactive gas reservoir. In one embodiment of the vacuum plasma treatment apparatus according to the present invention, such a reactive gas is one of hydrogen gas and oxygen gas that is not supplied.

[0092] In one of the just described embodiments of the vacuum plasma treatment apparatus according to the present invention, the second electrode is a magnetron sputter target of silicon.

[0093] In one embodiment of the vacuum plasma treatment apparatus, no reactive gas is fed to the housing in which the first electrode is located.

[0094] One embodiment of the vacuum plasma treatment apparatus according to the present invention comprises a first number of second plasma electrodes and a second number of first plasma electrodes, wherein the second number is smaller than the first number.

[0095] In one embodiment of the vacuum plasma treatment apparatus according to the present invention, the first number is at least two and the second number is one. Thus, for example, one single first plasma electrode can be provided for more than one plasma of at least two plasma treatment stations operating in a common vacuum receiver. Thereby, at least two of the at least two plasmas can be operated subsequently or simultaneously.

[0096] One embodiment of the vacuum plasma treatment apparatus according to the present invention comprises:

[0097] • a substrate carrier within the vacuum receiver, which is drivable in rotation about an axis, and which comprises a plurality of substrate carriers equidistant from the axis;

[0098] • a plurality of vacuum processing stations aligned with the transport path of the substrate carriers;

[0099] • at least two of the plurality of vacuum processing stations each comprising a second plasma electrode, the first plasma electrode for the at least two vacuum processing stations being common to the at least two vacuum processing stations and arranged coaxially with the axis.

[0100] In one of the just described embodiments of the vacuum plasma processing apparatus according to the invention, the plurality of vacuum processing stations comprises at least two magnetron sputter stations having a common first plasma electrode.

[0101] In one of the just described embodiments of the vacuum plasma processing apparatus according to the invention, the at least two magnetron sputter stations each have a silicon target.

[0102] In one of the just described embodiments of the vacuum plasma processing apparatus according to the invention, one of the at least two magnetron sputter stations is in fluid communication with a reactive gas inlet connected or connectable to a reservoir containing hydrogen gas, and the other of the at least two magnetron sputter stations is in fluid communication with a reactive gas inlet connected or connectable to a reservoir containing oxygen gas.

[0103] In one of the just described embodiments of the vacuum plasma processing apparatus according to the invention, the substrate carrier is continuously driven in rotation by the drive at least one 360 ° rotation, and the magnetron sputter source is continuously enabled for sputtering at least during one 360 ° rotation.

[0104] The two or more embodiments of the vacuum plasma processing apparatus according to the invention can be combined, unless contradicted.

[0105] According to a further aspect, the invention relates to a vacuum plasma processing apparatus comprising a substrate carrier within a vacuum receiver, at least one first plasma electrode and at least one second plasma electrode for generating a plasma therebetween. The first and second plasma electrodes are connectable to an electrical plasma supply arrangement establishing a first electrical potential to the first plasma electrode and a second electrical potential to the second plasma electrode, both of which are independently variable with respect to a system ground potential. The apparatus further comprises a negative feedback control loop for controlling at least one of the first electrical potential, the second electrical potential, a potential difference between the first electrical potential and the second electrical potential.

[0106] In one embodiment of the vacuum plasma processing apparatus according to the further aspect of the present invention, the measured momentary dominant entity in the negative feedback control loop consists of or comprises one of the first potential and the second potential relative to the reference potential, and the vacuum plasma processing apparatus comprises a sensing element for the respective first potential or second potential relative to the reference potential.

[0107] In one embodiment of the vacuum plasma processing apparatus according to the further aspect of the present invention, the adjusted entity in the negative feedback control loop consists of or comprises at least one of:

[0108] • the flow of reactive gas into the vacuum receiver;

[0109] • the potential difference.

[0110] The apparatus further comprises an adjustable flow controller for the flow of reactive gas into the vacuum receiver and / or an adjustable plasma supply arrangement for the potential difference between the first plasma electrode and the second plasma electrode.

[0111] The present invention further relates to a method of processing a substrate in a vacuum atmosphere or of manufacturing a processed substrate with the aid of a plasma generated between a first plasma electrode and a second plasma electrode, comprising: during processing, providing a predominantly coated first surface area -NPL- and a predominantly sputtered second surface area -PL- at at least one of the first plasma electrode and the second plasma electrode, whereby the ratio Q of the sum of the second surface areas to the sum of the first surface areas, both projected on the envelope trajectory of the respective plasma electrode, is selected to be:

[0112] 0.1 < Q < 9.

[0113] In one variant of the method according to the present invention, the ratio Q is selected to be:

[0114] 0.4 < Q < 1.

[0115] One variant of the method according to the present invention comprises supplying the first and second plasma electrodes with independently variable potentials.

[0116] The variants of the method according to the present invention are carried out by means of a vacuum processing apparatus according to the present invention or by means of one or more than one of the embodiments thereof.

[0117] The present invention will now be further illustrated with the aid of the accompanying drawings.

[0118] The accompanying drawings show:

[0119] Figure 1 : Vacuum plasma treatment apparatus as described in the context of the present invention is shown most schematically and simplified according to the most general aspect;

[0120] Figure 2 : Cut-out of a surface pattern of a plasma electrode in a device according to the present invention is shown most schematically and simplified;

[0121] Figure 3 is shown according to Figure 2 representations for explaining how different surface areas of a surface of a first plasma electrode of a device according to the present invention are interrelated;

[0122] Figure 4 : Cross-sectional representation of a cut-out of a surface pattern of a plasma electrode in a device according to the present invention is shown most schematically and simplified;

[0123] Figures 5 to 8 : Cut-outs of embodiments of a surface pattern of a plasma electrode in respective devices according to the present invention are shown respectively and in analogy to Figure 4

[0124] Figures 9 to 12 : Cut-outs of embodiments of a plasma electrode in respective devices according to the present invention are shown most schematically and simplified and in form of perspective views;

[0125] Figure 13 : Top view of an embodiment of a plasma electrode in a device according to the present invention is shown most schematically;

[0126] Figure 14 : Cross-sectional representation of a cut-out of a plasma electrode in a device according to the present invention;

[0127] Figure 15 : Embodiment of a plasma electrode in a device according to the present invention is shown in form of a schematic perspective view;

[0128] Figure 16 : Cross-sectional representation of a cut-out of an embodiment of a plasma electrode in a device according to the present invention;

[0129] Figures 17 to 19 : Cross-sectional representation of an embodiment of a plasma electrode in respective devices according to the present invention is shown most schematically;

[0130] Figure 20 : Principle of an embodiment of a plasma electrode in a device according to the present invention is shown most schematically, wherein a surface of the plasma electrode is realized by means of a cladding;

[0131] Figures 21 to 23 ​: according to the invention, the cut-out of the envelope of the respective surface pattern of an embodiment of a plasma electrode in the respective device according to the invention; Figure 20

[0132] Figure 24 : the cut-out of an embodiment of a plasma electrode cooled in a device according to the invention is shown schematically and simplified;

[0133] Figure 25 : a further embodiment of a plasma electrode cooled in a device according to the invention is shown schematically and simplified;

[0134] Figure 26 : an embodiment of a plasma electrode with a tapering cross-section in a device according to the invention is shown simplified and schematically;

[0135] Figure 27 : the electrical operation and the respective components in an embodiment of a device according to the invention are shown schematically and simplified;

[0136] Figure 28 : the negative feedback control of the electric potential at one of the plasma electrodes in a device according to the invention is shown schematically and simplified, and as a cut-out in a representation similar to Figure 27

[0137] Figure 29 : the negative feedback control of the electric potential at one of the plasma electrodes in a device according to the invention is shown most generally and simplified;

[0138] Figure 30 : an embodiment of a device according to the invention is shown in a representation similar to Figure 27 , wherein one of the plasma electrodes is a target of a sputter source or a workpiece carrier of an etching source;

[0139] Figure 31 : an embodiment of a device according to the invention has two at least similar plasma electrodes is shown in a representation similar to Figure 30

[0140] Figure 32 : the cut-out of an embodiment of a device according to the invention is shown in a representation similar to Figure 31

[0141] Figure 33 : a top view with respect to an embodiment of a device according to the invention is shown most schematically and simplified;

[0142] Figure 34 : a most schematically and simplified I-side view of an embodiment according to Figure 33

[0143] ​​​​​Figure 35 : a cut-out of an embodiment of the apparatus according to the present invention is shown most schematically and simplified, showing decoupling of different plasmas;

[0144] Figure 36 : a cross-sectional representation of a plasma electrode according to the present invention is shown schematically; Figure 34

[0145] Figure 37 : an embodiment of the apparatus according to the present invention is shown in a top view; Figure 36

[0146] Figures 38 to 41 : respective embodiments of a plasma electrode in a housing of a respective apparatus according to the present invention, in particular according to Figure 36 and 37 are shown schematically;

[0147] Figure 42 : a cross-sectional representation of a plasma electrode according to Figure 41 is shown schematically;

[0148] Figure 43 and 44 : respective embodiments of a plasma electrode in a housing of a respective apparatus according to the present invention, in particular according to Figure 36 and 37 are shown schematically;

[0149] Figure 45 : a cross-sectional representation of a plasma electrode according to Figure 44 is shown schematically;

[0150] Figure 46 and Figure 47 : respective embodiments of a plasma electrode in a housing of a respective apparatus according to the present invention, in particular according to Figure 36 and Figure 37 are shown schematically;

[0151] Figure 48 : a cross-sectional representation of a plasma electrode according to Figure 47 is shown schematically.

[0152] Figure 1 A vacuum plasma processing apparatus, also referred to as an arrangement, is shown most schematically and simplified, as the present invention according to the most general aspect is described in context.

[0153] ​​The vacuum plasma processing apparatus 1 comprises a vacuum receiver 3 operatively connected to a pumping arrangement 5. A substrate carrier 7 for one or more substrates 9 is provided, which is stationary or drivably movable in the vacuum receiver 3. The substrate carrier 7 can be operated in an electrically floating manner or under a reference potential, or can be operated under a desired bias potential. The one or more substrates 9 are exposed to a plasma PLA generated between a first plasma electrode 111 and a second plasma electrode 112. A working gas WG and / or a reactive gas RG is fed to the vacuum receiver 3 by means of a gas feed line arrangement 10. The gas feed lines are fluidically connected with a respective reservoir arrangement 12 containing the respective gas.

[0154] By means of an electric plasma supply arrangement (not shown in Figure 1 The respective electrode potential at the respective electrodes 111 and 112 and a plasma driving potential difference is established between the .

[0155] Now, we describe the first electrode 111 as defined above. The first electrode 111 generally has a surface of a metallic material, e.g. a metal. During some plasma processing processes, a material with a lower electrical conductivity than the metallic material of the surface of the electrode 111 is generated in the reaction space RS and deposited on the first electrode 111.

[0156] As an example, and as already mentioned above:

[0157] If the plasma processing is a sputter deposition by means of a magnetron sputtering or a non-magnetron sputtering, the second electrode 112 comprises a consumable sputter target. If the material of the target has a lower electrical conductivity than the metallic material of the surface of the first electrode, i.e. the "anode" of the sputter source, conventionally used, or if such a material is generated by reacting the target material in an atmosphere containing a reactive gas, the deposition of such a material with a lower electrical conductivity than the metallic material of the surface of the first plasma electrode 111 conventionally used on the first electrode destabilizes the sputter process.

[0158] If the plasma processing is a substrate etching, such a material with a relatively low electrical conductivity can be the material sputtered off (etched) from the substrate, or can be generated by the reaction of such an etched-off material with a reactive etching gas fed to the reaction space RS.

[0159] Moreover, the electrical conductivity of the material to be deposited on the substrate 9 resulting from a chemical reaction of the gases in the plasma PLA can be lower than the metallic material surface area of the first and second plasma electrodes conventionally used.

[0160] In any case where a material with a lower electrical conductivity than the surface metal material of the first electrode 111 conventionally used is present, the metal material surface area of the first electrode 111 becomes coated by this material. This phenomenon, which destabilizes the plasma process, for example by long-term drift, is known in the art and is referred to, for example, as "electrode hiding", "buried electrode", "vanishing" electrode, and the like, and should be reduced or even avoided by customizing the first plasma electrode according to the invention, which is different from the conventionally used first electrode 111 mentioned, accordingly.

[0161] As a further example of a conventionally used plasma electrode:

[0162] If the vacuum plasma process is operated with an Rf plasma, the surface of the first plasma electrode can also be a dielectric material surface of a layer of dielectric material deposited on the metal material base of the first plasma electrode. Such a dielectric layer provides a capacitive coupling of the Rf power source to the plasma. If the process generates a deposited material that is also a dielectric, the deposition of this material on the dielectric surface of the first electrode changes the capacitive coupling, which also destabilizes the process.

[0163] Thus, in other words, it is known in the field of vacuum plasma processing that all plasma electrode surfaces are simultaneously sputtered off and coated. On the target, as a second plasma electrode, sputtering, i.e. the release of material from the target surface, is predominant, but the "re-deposition" of material on the target from the reaction space does not disappear. In reactive sputtering, i.e. in the sputter deposition of layers on a substrate, especially if the deposited material has a lower electrical conductivity than the target material, the "re-deposition" on the target surface can lead to a so-called "target poisoning".

[0164] As we have defined above, the first plasma electrode is predominantly exposed to poisoning deposition rather than to sputtering.

[0165] The inventors of the present invention have recognized that the specific customization of the surface of the first plasma electrode 111 leads to a rapid self-cleaning of a part of the surface after the plasma ignition and thus prevents the destabilization of the plasma process by the first plasma electrode 111 becoming buried.

[0166] This is generally and surprisingly established by customizing the surface of the body of the first plasma electrode 111 such that along a first region of this surface, the plasma can not burn, and along a second remaining region of this body, the plasma does burn. Mainly along the first surface region, a material can be deposited that is less conductive than the metallic material of the second surface region of the body. The second surface region is mainly sputtered, establishing and maintaining surface contact of the metallic material with the plasma, or more generally, maintaining its initial properties as a metallic material or as a defined property of capacitive coupling.

[0167] One can thus say that the surface of the body of the first plasma electrode 111 is patterned by a first surface region that does not contribute to the electrode effect and a second surface region that does contribute to the electrode effect.

[0168] Figure 2 A portion of the surface 30 of the body 31 of the first plasma electrode 111 according to the present application is shown most generally. Along the surface region 30NPL, the plasma PLA is prevented from burning, whereas the plasma PLA does burn along the remaining surface region 30PL.

[0169] Figure 3 The body 31 of the first plasma electrode 111 is again shown with a first surface region 30NPL and a second surface region 30PL. The body 31 is surrounded by a geometric locus enclosure 31L. The ratio Q of the sum of the projections 30PLp of the second surface region 30PL onto the geometric locus enclosure 31L and the sum of the projections 30NPLp of the first surface region 30NPL onto the geometric locus enclosure 31L is thus chosen to be

[0170] 0.1 ≤ Q ≤ 9

[0171] And thus, in today’s practice of embodiments is:

[0172] 0.4 ≤ Q ≤ 1.

[0173] The surface region 30PL is a metallic material, or a dielectric material that is a layer of dielectric material deposited on a metallic material base of the body 31.

[0174] According to Figure 4 , the surface region 30NPL is formed by a void recess 33 in a metallic material surface 30m of the body 31. The metallic material surface 30m can be a surface of the metallic material body 31 or a surface of a metallic material layer, as schematically shown in dashed lines at 30mL. The metallic material surface 30m / 30mL is operated at a first electric potential 111.

[0175] The dimensions of the recesses 33 are designed so as to prevent the plasma PLA from burning therein, so that, as known to the person skilled in the art, their minimum cross-sectional extent D is less than twice the dominant Debye length. Only the surface of the recesses 33, which is exposed to the plasma PLA, becomes coated with the material generated by the vacuum plasma treatment process, which can have a relatively low electrical conductivity, less conductive than the metallic material of the surface 30m. In contrast, the metallic material surface area 30 PL is increasingly sputtered.

[0176] By way of trial, these phenomena can be explained as follows:

[0177] In the surface recesses 33 of the metallic material, there is no plasma burning, since their dimensions are designed so that the minimum diameter of their opening is less than twice the Debye length. There is no Debye length in the vicinity of the recess surface. Therefore, there is no potential difference to accelerate charged particles towards the recess surface. These particles are deposited only in the recesses 33. Since there is no plasma in the recesses 33, the electrical conductivity is relatively low, and the electric field and the current between the first plasma electrode and the second plasma electrode increasingly concentrate on the outer metallic material area 30 PL. There, in the presence of a dominant Debye length and a high electrical conductivity, the charged particles are increasingly accelerated towards the surface and sputter the surface area 30 PL, thus preventing the net deposition of the relatively low-conductivity material there.

[0178] However, the accumulation of the coating in the recesses 33 over time and the corresponding increase in sputtering at the surface area 30 PL still leads to some drift of the process.

[0179] This leads the inventors to pre-apply a surface area 30 NPL of electrically insulating material, such as a ceramic material, thus establishing stable initial conditions from the start of the treatment.

[0180] According to Figure 5 an embodiment, the void recesses 33 in the metallic material surface 30m of the body 31 are pre-coated with a dielectric material coating 34a, for example of a ceramic material.

[0181] According to Figure 6 an embodiment, the recesses 33 in the metallic material surface 30 of the body 31 or having a metallic material coating 30mL thereon are filled with a dielectric material, for example with a plug 34b, for example of a ceramic material.

[0182] According to Figure 7 an embodiment, the metallic material surface 30 of the body 31 is pre-coated with areas or "islands" 30 NPL of dielectric material, for example with a layer 34c of ceramic material.

[0183] Taking into account Figure 7 , Figure 8The pattern of the surface of the first plasma electrode 111 suitable for Rf plasma is shown again schematically. Here, the second surface area 30PL and the first surface area 30NPL are surface areas of respective dielectric material layers. The thickness of the dielectric material and those layers forming the second surface area 30PL provides a much greater coupling capacity than the thickness of the dielectric material and those layers providing the first surface area 30NPL.

[0184] Please also note that when the second surface area 30PL is implemented with a dielectric material layer, the first surface area 30NPL can be implemented according to Figures 4 to 6 .

[0185] According to an embodiment of Figure 9 , the body 31 is split into a plurality of portions 31a and 31b… and a sandwich 31c of dielectric material is sandwiched between two subsequent portions 31a, 31b which are of metallic material or coated with a layer of metallic material -30mL-. The metallic material portions are electrically interconnected (not shown in the figures) and operate at a first electrical potential 111.

[0186] While Figure 4 , Figure 5 and Figure 6 show recesses with a hole shape, Figures 10 to 12 shows recesses 33 implemented as gaps between plate-like webs of metallic material or coated with a layer of metallic material.

[0187] Figures 13 to 16 More specific embodiments of the electrode body 31 of the first plasma electrode 111 are shown. According to Figure 13 which shows a top view of the body 31, the body 31 extends along an axis A. While this axis can be curved, in today’s implemented embodiments the axis A is straight.

[0188] Furthermore, and although the top view shape of the body 31 according to Figure 13 is circular, it can also be, for example, elliptical or polygonal.

[0189] According to an embodiment of Figure 14 , the body 31 is of metallic material or coated with a layer of metallic material and comprises recesses implemented by grooves 33a surrounding the axis A. Thus, Figure 13 embodiments are in line with the general embodiments of Figure 4 . Please note that a plurality of grooves 33a can be replaced by one or more helical grooves (not shown in the figures) surrounding the axis A and along the body 31. Obviously, according to Figures 4 to 8All general forms of the first surface region 30NPL can be realized as a surface region extending helically around the axis A, resulting in a second surface region 30PL that is also helical.

[0190] Figure 14 The second surface region 30PL in the 111 works at a first electrical potential.

[0191] Figure 15 An example of the body 31 of the first plasma electrode 111 is shown, in which the second surface region 30PL is helically wound around a straight axis A. Thereby, the second surface region is realized along a helically wound line 100. The second surface region 30PL is mainly defined along the outer circumference of the line 100. The distance between adjacent turns of the helix is D, and the radial distance from the central feed 102 to the inner circumference of the helix can also be at most D. The helix is independent except for the electrical connection to the central feed 102. Please note that in the attached figures, the hatching does not indicate a cross section.

[0192] For process pressures conventionally used for sputtering, like also in Figure 14 The distance D is chosen to be in the range

[0193] 1 mm ≤ D ≤ 110 mm, in particular

[0194] 7 mm ≤ D ≤ 15 mm.

[0195] Figure 16 Embodiments of the Figure 14 Figure 14 The recesses or gaps of the Figure 4 Figure 5 are not void, nor are they coated with a layer of dielectric material (as in the general embodiments of the Figure 6 Figures 17 to 19 Further embodiments of the body 31 of the first anode 111 are shown, which are all along a straight axis A. Please note that in these attached figures, the hatching does not indicate a cross section either.

[0196] Figure 20 Embodiments of the body 31 are shown schematically, which are examples of extending along an axis A. The body 31 comprises a core 106 and an envelope 108, which defines a pattern of a first surface region 30NPL and a second surface region 30PL, as becomes apparent in the context of the Figures 21 to 23

[0197] According to​​​​​​​​Figure 21 The cladding 108 has a pattern of void openings 110 through which the second surface area 30PL is freely accessible once applied to the core 106 having a surface of metallic material. The cladding 108 itself is a dielectric material.

[0198] According to Figure 22 The cladding 108 has a pattern of void openings 110 through which the first surface area 30NPL is freely accessible once applied to the core 106 having a surface of dielectric material. The cladding 108 itself is a metallic material.

[0199] According to Figure 23 The metallic material cladding 108 carries the pattern of the first surface area 30NPL and can be applied to the core 106 independent of the core material. In contrast, the cladding 108 can be a dielectric material and carries the pattern of the second surface area 30PL (not shown in the figures).

[0200] The cladding 108 can be a maintenance replacement part and thus easily replaceable on the core 106.

[0201] The person skilled in the art realizes now a multitude of variants to realize the surface pattern of the body of the first plasma electrode 111 according to the present application and according to its specific requirements.

[0202] All embodiments of the body 31 can be cooled, which can be achieved by means of a cooling fluid guided through the body 31 or by mounting the body to a heat sink member.

[0203] According to Figure 24 Embodiments, a coaxial through-hole 40 is provided at the center and along the axis A of the metallic material body 31 or the core 106 of the body 31. A cooling fluid tube 42 extends along the hole 40 and discharges the cooling fluid FL at the bottom of the through-hole 40. The cooling fluid FL is discharged from the through-hole 40 at one end of the body 31 or the core 106 (not shown in the figures).

[0204] According to Figure 25 Embodiments, the metallic material body 31 or the core 106 is mounted to a heat sink member comprising a channel arrangement 40a through which the cooling fluid FL flows. A member or interlayer 64 of electrically insulating material is provided between the body 31 or the core 106 and the heat sink member 62 and has a good thermal conductivity, like e.g. AlN, which allows to operate the heat sink member on the system ground potential G, which is thermally tightly coupled to the body 31, but the body 31 is still electrically isolated from the system ground.

[0205] According to Figure 26In any form of implementation, but especially according to Figures 13 to 19 In one embodiment, the body 31 is surrounded by a geometric trajectory GL, which serves as a geometric shell and is considered to taper gradually in at least one direction S along axis A. Depending particularly on the mounting position of the first electrode 111 in the vacuum receiver 3, this local or overall taper allows control over the distribution of the coating / sputtering effect along the body 31, and in particular, enables uniformity of the distribution.

[0206] We now describe how the first and second plasma electrodes operate electrically in an embodiment of the arrangement according to the invention.

[0207] like Figure 27 As shown, and as part of the invention, both electrodes 111 and 112 are electrically operated, such that the potential of the respective electrodes is... 111 and 112 can vary independently of the system ground potential G applied to the vacuum receiver 3. The first plasma electrode 111 and the second plasma electrode 112 operate with electrical isolation as shown by isolators 14 and 16. A floating plasma supply source arrangement 18 is operatively connected to plasma electrodes 111 and 112 and applies a potential difference Δ between the first and second plasma electrodes. The plasma supply source arrangement 18 can be customized to generate at least one of DC, pulsed DC, HIPIMS, and AC up to RF.

[0208] The substrate carrier 7 can be grounded at the system ground potential G or at the bias potential ( Figure 27 (Not shown) is electrically operated in a floating manner, and the bias potential can be DC, up to AC via RF. Note that if etching is performed, the substrate carrier 7 can be implemented via the second plasma electrode 112. Considering the low plasma impedance from plasma electrodes 111 and 112 to system ground G, electrodes 111 and 112 are free to take their respective potentials. 111 and 112, thereby maintaining the potential difference Δ established by the plasma supply source arrangement 18. Thus, and in contrast to using the grounded metal wall of the vacuum receiver 3 as the first plasma electrode, according to the present invention and as described above with respect to several embodiments, the first plasma electrode 111 becomes locally well defined such that the current path from any second plasma electrode to the first electrode 111 loads the first plasma electrode 111 with a current concentrated on the second surface region -PL- of the surface pattern.

[0209] The first electrode 111 can be accessed via impedance element Z11 (see also...). Figure 30) to a reference potential, for example, to a system ground potential G, the impedance element Z11 appears in parallel to the plasma impedance Z111 and is chosen such that it does not practically affect the overall parallel impedance Z111 / / Z11. In today's practical implementations, the impedance Z11 is realized by a resistive element R, wherein there is an effective

[0210] 50 Ω ≤ R ≤ 250 kΩ,

[0211] Thereby, in one embodiment, R = 1 kΩ.

[0212] The impedance element Z11 can be realized by means of at least one passive electronic element and / or by means of at least one electrically active element (e.g. a diode) and / or at least one electrically active controllable element (e.g. a FET). By adjusting the impedance element Z11 as described by the dashed line at Adj in Fig. Figure 27 , the self-cleaning effect of the second surface area -PL- of the surface pattern of the first electrode 111 can be adjusted.

[0213] It is further provided that the impedance element Z11 can improve the ignition of the plasma PLA and can be used for sensing the potential of the first plasma electrode 111 with respect to a reference potential, for example, the system ground potential G, as described later. 111.

[0214] According to Figure 28 , a sensing element Z11' is provided, thereby sensing the instantaneous dominant potential of the first plasma electrode 111 with respect to a reference potential, for example, the system ground potential G 111. For example, the voltage Uz11 across the impedance element Z11 can be sensed Figure 27 . The respective voltage Uz11 indicates the measured control signal in a negative feedback control loop of the control signal Uz11 and is used as the measured control signal in a negative feedback control loop of the control signal Uz11. As an adjusting entity, the flow of the reactive gas is adjusted and / or the output signal of the plasma supply arrangement 18 is adjusted, as indicated by the dashed line. Thus, the measured control signal Uz11 is compared at a difference forming unit 22 with a preset value Uz110 of the control signal provided at the unit 22. A control deviation signal Δ at the output of the difference forming unit 20 is guided via a controller 24 to a flow regulating valve 26, thereby adjusting the flow of the reactive gas or gas mixture from a reactive gas reservoir 28 containing such reactive gas or gas mixture into the vacuum receiver 3. Additionally or alternatively, the control deviation signal Δ acts on a control input C of the plasma supply arrangement 18.

[0215] Figure 29 The combination of Figure 28a more general negative feedback control loop as explained in the context of

[0216] According to Figure 28 The sensed voltage Uz11 is fed to a processing unit 60. The processing unit 60 calculates the instantaneous prevailing value of a function F(Uz11) of Uz11, which function can be a multivariate function F(Uz11, X2, X3...) thereby taking additional input signals X2, X3... into account. The result of the processing in the processing unit 60 is the instantaneous prevailing value of the function F.

[0217] In a preset unit 22a, a desired value of the function F or a desired time course F o of the function F is set. The instantaneous prevailing output signal of the processing unit 60 is compared with the constant or time-varying desired value F o of the function F at a difference forming unit 20a. The output signal of the difference forming unit 20a acts as a control deviation Δ via a controller unit 24a on a regulating valve 26 and / or on a control input C of the plasma supply arrangement 18 - and possibly on additional regulating means for the plasma processing process, such as for example on an adjustable substrate bias 27a, a process pressure 27b, etc.

[0218] It is assumed that the negative feedback control as described and explained in the context of Figure 28 and Figure 29 is an invention in itself.

[0219] In a more general approach, by such a negative feedback control loop (which can be inventive in itself), at least one of the first potential 111 and the second potential 112 and the potential difference Δ between the first potential 111 and the second potential 112 is controlled to remain or follow a respectively preset constant or time-varying value.

[0220] Figure 30 An embodiment of a vacuum plasma processing apparatus according to the invention and as discussed so far is shown in a most schematic and simplified way. The same reference numerals are used as introduced so far. Please note that the impedance Z11 and the negative feedback control loop (not shown in Figure 30 ) just described are optional.

[0221] The reference 29 describes a working gas reservoir, for example containing argon, through which working gas WG is fed into the vacuum receiver 3 as a replacement or supplement to the reactive gas RG from the reactive gas reservoir 28. In this embodiment, the second plasma electrode can be the substrate carrier for the substrate 9 shown in dashed lines, and the vacuum plasma process can be an etching of this substrate 9.

[0222] So far, we have mainly referred to plasma processes in which mainly the second plasma electrode 112 is consumed and the first plasma electrode 111 is implemented according to the application. According to the application, both plasma electrodes 111, 112 are powered, for example, as shown and described in the context of Figure 27

[0223] In certain applications, such as in PECVD, neither of the plasma electrodes is consumed, and neither of these electrodes should be buried or hidden by a covering of material, in particular a material that is less conductive than the metal material surface of the respective plasma electrode.

[0224] In such cases or applications, both electrodes 111 and 112 can be constructed according to the application, but not necessarily identically. This is shown schematically and simplified in Figure 31

[0225] The same reference signs as introduced so far are used. No additional explanation is required. The gas reservoir 28' for the PECVD process contains CVD-G gas, which chemically reacts in the plasma between the electrodes 111 and 112, resulting in a material deposited on the substrate 9.

[0226] According to the embodiment of Figure 32 The electrode body 31 is located in a housing 36 of metal material or dielectric material and remote from this housing 36. If the housing 36 is of metal material, it is operated in electrically floating fashion or on a reference potential, for example the system ground potential G. A working gas reservoir 29 containing, for example, argon, supplies working gas WG to the gap V between the electrode body 31 and the housing 36. In one embodiment of the device, the working gas WG fed to the entire device is fed to the housing 36.

[0227] ​​The gap V is in communication with the reaction space RS via a coupling opening 38a or 38b. The coupling opening 38a or 38b is large enough to allow the plasma PLA to expand into the gap V. The working gas WG flows from the gap V into the reaction space RS through the coupling opening 38a or 38b. It can be necessary or unnecessary to additionally supply working gas WG into the reaction space. If a reactive gas is used, or as in PECVD, material components are to be deposited on the substrate in gaseous form, such a gas RG is fed to the reaction space RS outside the housing 36 and / or within the gap V. In one embodiment of the apparatus, such a gas RG is fed to the reaction space RS remote from the housing 36, as Figure 32 indicated.

[0228] Due to the pressure stage effect of the coupling opening 38a or 38b, the pressure of the working gas WG in the gap V can be slightly higher than in the reaction space RS, resulting in a shorter mean free path and thus a shorter dark space distance in the gap V than in the reaction space RS.

[0229] The housing 36 can be a maintenance replacement part and thus be installed in an easy-to-replace manner.

[0230] Alternatively or additionally, the inner surface of the housing 36 can be protected by a shield-inlay 70 as indicated by the dashed line. The shield-inlay 70 is an easy-to-maintain replaceable part.

[0231] If the shield-inlay 70 is of a metallic material, it is operated in an electrically floating manner or on a reference potential, for example on the system ground potential G. Alternatively, the shield-inlay 70 can be of a dielectric material.

[0232] The body 31 should not be seen directly from the substrate carrier 7, in particular not directly from the substrate 9 thereon. This is to avoid deposition of material sputtered from the body 31 on the substrate 9. This is achieved by positioning and shaping the coupling opening 38 accordingly, and / or by a movable baffle 72 between the body 31 and the substrate carrier 7. If the coupling opening is tailored as indicated schematically at 38a, the housing 36 itself blocks the line of sight LS 31 from the substrate carrier 7 to the body 31. If the coupling opening is tailored as indicated schematically at 38b, the respective exposure is achieved by means of a baffle 72, which can be moved to account for different requirements, for example with respect to different substrates. If made of a metallic material, the baffle 72 is either operated in an electrically floating manner or on a reference potential, for example on the system ground potential G.

[0233] If desired, the housing 36 can be cooled by providing an arrangement of channels for a cooling fluid along the walls of the housing 36 (not shown in the figures).

[0234] If the first plasma electrode 111 is applied in combination with a conventional plasma processing station (e.g. a magnetron sputter station) having its own two plasma electrodes, one of the plasma electrodes of such a station at the anode of the magnetron sputter station can be replaced by the first plasma electrode 111 according to the present application.

[0235] As Figure 32 In some embodiments, the first electrode 111 can be adjustably mounted in the housing 36 with respect to its positioning, in particular with respect to its positioning along the axis A, as indicated in dashed lines at W. The first plasma electrode can even be mounted so as to be removable from the housing 36 and re-insertable into the housing 36. This can be advantageous for optimizing plasma ignition and for adjusting the current path between the first plasma electrode 111 and the second plasma electrode 112.

[0236] If more than one plasma processing station is operated in a common reaction space, the respective plasma of the plasma processing stations can be served by a single first plasma electrode 111 according to the present application.

[0237] Figure 33 And Figure 34 A top view and a cross-sectional view of an embodiment of the arrangement according to the present application are shown most schematically and simplified.

[0238] In the vacuum receiver 3, a substrate carrier 7 is drivably rotatable. The substrate carrier 7 carries substrates 9. The substrates 9 are passed along their movement path through a plurality (e.g. five) of plasma processing stations 50, which are all operated in a common reaction space RS. Each of the plasma processing stations 50 comprises a second plasma electrode 112. At one site along the vacuum receiver, e.g. where a further processing station can be mounted, a first electrode 111 according to the present application is mounted. The first plasma electrode 111 is a plasma electrode common to the plasma processing stations 50 as indicated by the respective plasma supply arrangement 18. The plasma processing stations 50 with the common first electrode 111 can be operated simultaneously or subsequently or in a manner that they are operated simultaneously only during a part of their respective operation time, thus in effect in an "overlapping" time span.

[0239] Figure 35 A plasma processing arrangement according to the present application is shown most schematically and simplified. A plasma PLA is operated between the second plasma electrode 112 and the first plasma electrode 111. The plasma processing stations 78 are operated in a common reaction space RS. The plasma PLS of the plasma processing stations 78 makes use of the wall of the vacuum receiver 3 as first electrode, and thus, the resulting plasma becomes relatively widely distributed in the reaction space RS.

[0240] In contrast thereto, the current path between the two plasma electrodes 111 and 112 is concentrated on the first plasma electrode 111 and there on the second surface area - PL - of the surface pattern. Thus, according to the present application, the plasma PLA to the first plasma electrode 111 is concentrated towards the locally well-defined first plasma electrode 111. Thereby, as often required, the plasma PLA becomes essentially decoupled from the plasma PLS.

[0241] As already mentioned, the present application is most suitable to be applied at a magnetron sputter source, because the second plasma electrode 112 is a target or target holder, while the first electrode 111 is a counter electrode, i.e. an "anode". Thereby, the target can be a silicon target. If reactive sputtering is carried out at such a magnetron sputter source, the reactive gas can be oxygen or hydrogen, in order to deposit a silicon oxide or a hydrogenated silicon layer on the substrate 9.

[0242] In Figures 36 to 48 a more specific apparatus according to the present application is schematically shown.

[0243] According to Figure 36 and Figure 37 the substrate carrier 201 is rotatable about an axis Al by means of a drive 203, continuously driven at least 360 ° of rotation. A plurality of substrates 9 is located on the substrate carrier 201, held by respective substrate carriers (not shown), equidistant to the axis Al.

[0244] The substrates 9 along their rotation path pass at least two vacuum process stations 205, at least one of which is a vacuum plasma process station, thereby especially a magnetron sputter station with a target 207 as shown at 205a. In one embodiment, as shown in Figure 37 at least two magnetron sputter stations 205a are provided. The vacuum process stations, and thereby especially the vacuum plasma process stations, do indeed act collectively on the substrates 9 in the reaction space RS.

[0245] At the vacuum plasma process station comprising one or more magnetron sputter stations 205a, the first plasma electrode 111 is typically realized in the housing 36 and is located coaxially to the axis Al. A working gas - WG - inlet to the reaction space RS is provided at the housing 36, while the reactive gas RG, if provided, is fed to the reaction space RS directly or via the respective vacuum process station 205, thereby to the one or more magnetron sputter stations 205a.

[0246] The housing 36 is separated from the reaction space RS by means of a dielectric material shield 209, which can be said to be part of the wall of the housing 36. According to Figure 36The opening 38 is provided through the sheath. In one embodiment providing at least two magnetron sputtering sources 205a, the target of the at least two magnetron sputtering sources 205a is silicon, one of these sources is fed oxygen as the reactive gas RG, and the other is fed hydrogen as the reactive gas RG. Argon can be used as the working gas WG. The corresponding reactive gas can be fed into the reaction space RS near the target 207 instead of being fed into the magnetron sputtering source.

[0247] The plasma PLA obtained from the target 207, which serves as the second plasma electrode 112, is qualitatively shown by dashed lines, which is concentrated onto the common first electrode 111.

[0248] Figure 36 and Figure 37 In the embodiments, the body 31 of the first electrode 111 can be implemented according to any of the embodiments described above, extending along a linear axis (such as along axis A1).

[0249] Figures 40 to 48 Different embodiments of the first plasma electrode 111 in the housing 36 are shown, as applied to... Figure 36 and Figure 37 Examples of this type of electrode for the device. Note that the shaded lines in these figures do not indicate a cross-section.

[0250] The same reference numerals are used for the same entities as previously applied, and thus those skilled in the art will fully understand these embodiments.

[0251] Figure 42 yes Figure 41 A schematic cross-sectional view of an example. Figure 45 yes Figure 44 A schematic cross-sectional view of the example, and Figure 48 yes Figure 47 A schematic cross-sectional view of an example.

Claims

1. A vacuum plasma processing apparatus comprising: - a substrate carrier within a vacuum recipient, at least one first plasma electrode and at least one second plasma electrode for generating a plasma therebetween; - said at least one first plasma electrode and said at least one second plasma electrode are mounted within said vacuum recipient such that they can be freely adapted to a first potential and a second potential, respectively; - said second plasma electrode is a target to be sputtered, or a substrate carrier of a substrate to be etched, or a substrate to be etched; - said at least one first plasma electrode and said at least one second plasma electrode are connected to a floating electrical plasma supply, thereby establishing a potential difference between said first potential and said second potential; - said at least said first plasma electrode comprises an electrode body having an externally patterned surface, said surface comprising first surface areas and second surface areas, said first surface areas contributing nothing to plasma electrode effect and being a metallic material or a dielectric material, said second surface areas being plasma electrode effective and being a metallic material or being a surface of a dielectric material layer deposited on a metallic material, said metallic material of said first surface areas or said metallic material on which said dielectric material layer is deposited being operatively connected to said electrical plasma supply.

2. The vacuum plasma processing apparatus of claim 1, wherein, In a new state of at least said first plasma electrode, and in a projection of said pattern on an envelope trajectory of said body, a ratio Q of a sum of projected areas of said second surface areas of said pattern to a sum of projected areas of said first surface areas is 0.1 ≤ Q ≤ 9。 3. The vacuum plasma processing apparatus of claim 1, wherein, In a new state of at least said first plasma electrode, and in a projection of said pattern on an envelope trajectory of said body, a ratio Q of a sum of projected areas of said second surface areas of said pattern to a sum of projected areas of said first surface areas is 0.4 ≤ Q ≤ 1。 4. The vacuum plasma processing apparatus of one of claims 1 to 3, in a new state of at least said first plasma electrode, at least some of said second surface areas and at least some of said first surface areas being metallic material surface areas.

5. The vacuum plasma processing apparatus of one of claims 1 to 3, in a new state of at least said first plasma electrode, at least some of said first surface areas being dielectric material surfaces and at least some of said second surface areas being metallic material surfaces.

6. The vacuum plasma processing apparatus of one of claims 1 to 3, in a new state of at least said first plasma electrode, at least some of said first surface areas and at least some of said second surface areas being dielectric material surface areas.

7. The vacuum plasma processing apparatus of one of claims 1-3, wherein, said body comprises a core and an envelope, and a pattern of said patterned surface is defined by said envelope.

8. The vacuum plasma processing apparatus of claim 7, wherein, said envelope is a maintenance replacement part.

9. The vacuum plasma processing apparatus according to one of claims 1-3 and 8, in the new state of the at least first plasma electrode, the second surface area is a metallic material, and the vacuum plasma arrangement is configured to generate, in operation, a material in the space exposed to the vacuum recipient of at least the first plasma electrode, the material having an electrical conductivity lower than the electrical conductivity of the metallic material of the second surface area.

10. The vacuum plasma processing apparatus according to one of claims 1-3 and 8, wherein, The electrode body extends along a straight axis.

11. The vacuum plasma processing apparatus of one of claims 1-3 and 8, wherein, The electrode body is surrounded by a geometric trace body having an elliptical or circular or polygonal cross section.

12. The vacuum plasma processing apparatus of one of claims 1-3 and 8, wherein, The electrode body is surrounded by a geometric trace body which, considered from one direction, has a tapering cross-sectional profile.

13. The vacuum plasma processing apparatus of one of claims 1-3 and 8, wherein, The first surface area of the patterned surface comprises at least one of: - a void recess having a metallic material surface; - a void recess having a metallic material surface covered by a dielectric material layer; - a recess having a metallic material surface and being filled with a dielectric material.

14. The vacuum plasma processing apparatus of one of claims 1-3 and 8, wherein, At least some of the first surface area of the pattern are regions of dielectric material on a metallic material.

15. The vacuum plasma processing apparatus of claim 14, wherein, The second surface area of the pattern are regions of dielectric material on a metallic material, whereby the regions of dielectric material of the second surface area are thinner than the regions of dielectric material of the first surface area, and / or the dielectric constant of the dielectric material of the second surface area is greater than the dielectric constant of the dielectric material of the first surface area.

16. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, wherein, The electrode body extends along an axis, the first surface area comprising at least one groove around the axis.

17. The vacuum plasma processing apparatus according to claim 16, the at least one groove being a helical groove or an annular groove.

18. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, wherein, The second surface area comprises at least one helical region around the axis of the body.

19. The vacuum plasma processing apparatus of claim 18, wherein, The helical region is a wire of metallic material.

20. The vacuum plasma processing apparatus of claim 18, wherein, The wire is self-supporting.

21. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, wherein, The first surface area comprises gaps between protruding webs.

22. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, wherein, The first surface area comprises at least one gap between mutually spaced metallic material plates.

23. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, wherein, The first surface area comprises at least one dielectric material plate sandwiched between metallic material plates.

24. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, wherein, The body is cooled.

25. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, wherein, The body comprises a channel arrangement for a cooling medium or is mounted to a heat sink.

26. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, comprising: An impedance element is interconnected between a metallic material portion of the body of the first plasma electrode and a portion of the apparatus operating on a reference potential.

27. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, comprising: A negative feedback control loop for controlling at least one of the first potential, the second potential, the potential difference.

28. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, comprising: A negative feedback control loop, wherein the measured dominant entity consists of the first potential to be negatively feedback controlled, and the vacuum plasma processing apparatus comprises a sensing element for the first potential relative to a reference potential.

29. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, comprising: a negative feedback control loop, wherein the measured dominant entity consists of or comprises a first electric potential and the vacuum plasma processing apparatus comprises a sensing element for the first electric potential relative to a reference electric potential, the regulated entity in the negative feedback control loop consists of or comprises a reactive gas flow and / or the electric potential difference between the first plasma electrode and the second plasma electrode, and the vacuum plasma processing apparatus comprises an adjustable flow controller for the reactive gas into the vacuum receiver and / or an adjustable plasma power supply arrangement for the electric potential difference.

30. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, wherein, the first plasma electrode is enclosed in a housing in the vacuum receiver, the housing is remote from and electrically isolated from the first plasma electrode and has at least one opening exposed to a reaction space in the vacuum receiver and tailored to allow the plasma to establish between the first plasma electrode and the second plasma electrode.

31. The vacuum plasma processing apparatus of claim 30, wherein, the housing is cooled.

32. The vacuum plasma processing apparatus according to claim 30, the housing comprises a channel arrangement for a cooling medium or is mounted to a heat sink.

33. The vacuum plasma processing apparatus according to claim 30, at least a portion of the housing is a metallic material and is electrically operated in a floating manner or connected to a reference electric potential like a system ground potential.

34. The vacuum plasma processing apparatus according to claim 30, at least a portion of the housing is a dielectric material.

35. The vacuum plasma processing apparatus according to claim 34, the opening is in the portion of dielectric material.

36. The vacuum plasma processing apparatus according to claim 30, at least a portion of the housing is a maintenance replacement part or the housing comprises a shield as a maintenance replacement part at least along a major portion of its inner surface.

37. The vacuum plasma processing apparatus according to claim 30, the housing comprises a metallic material shield at least along a major portion of its inner surface, the metallic material shield is electrically operated in a floating manner or connected to a reference electric potential like on a system ground potential.

38. The vacuum plasma processing apparatus of claim 30, comprising: a working gas inlet, the working gas inlet is discharged in the housing and connectable or connected to a working gas reservoir.

39. The vacuum plasma processing apparatus according to claim 30, the vacuum receiver comprises a working gas inlet discharged in the vacuum receiver and consists of a working gas inlet discharged in the housing.

40. The vacuum plasma processing apparatus according to one of claims 1-3 and 8, 15, 17, 19-20, 31-39, the body of the first plasma electrode is hidden from a line of sight from the substrate carrier.

41. The vacuum plasma processing apparatus of claim 30, the body being hidden from line of sight from the substrate carrier by means of the housing or by means of a fixed or adjustable baffle across the opening of the housing.

42. The vacuum plasma processing apparatus of claim 41, the baffle being of a metallic material and electrically operated in floating fashion or connected to a reference potential such as a system ground potential.

43. The vacuum plasma processing apparatus of claim 41, the baffle being of a dielectric material.

44. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, 31-39, 41-43, wherein, The second plasma electrode is configured according to the first plasma electrode.

45. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, 31-39, 41-43, the second plasma electrode being a target or target holder of a magnetron sputter source or a substrate holder or substrate of a plasma etch source and having a source anode consisting of the first plasma electrode.

46. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, 31-39, 41-43, the second plasma electrode being a target of a magnetron sputter source, the target being silicon.

47. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, 31-39, 41-43, the vacuum receiver comprising a reactive gas inlet connectable or connected to a reactive gas reservoir.

48. The vacuum plasma processing apparatus of claim 47, wherein, The reactive gas is one of oxygen and hydrogen.

49. The vacuum plasma processing apparatus of claim 48, the second plasma electrode being a magnetron sputter target of silicon.

50. The vacuum plasma processing apparatus of claim 47 wherein, No reactive gas is fed to the housing in which the first plasma electrode is located.

51. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, 31-39, 41-43, 48-50, comprising: A first number of the second plasma electrodes and a second number of the first plasma electrodes, the second number being smaller than the first number.

52. The vacuum plasma processing apparatus of claim 51, wherein, The first number is at least two and the second number is one.

53. The vacuum plasma processing apparatus of one of claims 1-3 and 8, 15, 17, 19-20, 31-39, 41-43, 48-50, 52, comprising: • a substrate conveyor within the vacuum receiver, drivably rotatable about an axis and comprising a number of substrate carriers equidistant from the axis; • more than one vacuum processing station aligned with the transport path of the substrate carriers; • at least two of the more than one vacuum processing stations each comprising a second plasma electrode, the first plasma electrode for the at least two vacuum processing stations being common to the at least two vacuum processing stations and provided coaxially to the axis.

54. The vacuum plasma processing apparatus of claim 53, the more than one vacuum processing station comprising at least two magnetron sputter stations with the common first plasma electrode.

55. The vacuum plasma processing apparatus of claim 54, the at least two magnetron sputter stations each having a silicon target.

56. The vacuum plasma processing apparatus according to one of claims 54 or 55, one of the at least two magnetron sputter stations being in fluid communication with a reactive gas inlet connected or connectable to a gas reservoir containing hydrogen gas, the other of the at least two magnetron sputter stations being in fluid communication with a reactive gas inlet connected or connectable to a gas reservoir containing oxygen gas.

57. The vacuum plasma processing apparatus of claim 53 wherein, The substrate conveyor is driven at least continuously by a drive in one 360 ° rotation, and the magnetron sputter source is continuously enabled for sputtering at least during said one 360 ° rotation.

58. The vacuum plasma processing apparatus of claim 1 comprising: - a substrate carrier in a vacuum receiver, at least one first and at least one second plasma electrode for generating a plasma therebetween; - the at least one first plasma electrode and the at least one second plasma electrode are mounted in the vacuum receiver such that they can be freely adapted to a first and a second electric potential, respectively; - the second plasma electrode is a target to be sputtered, or a substrate carrier of a substrate to be etched, or a substrate to be etched; - the at least one first plasma electrode and the at least one second plasma electrode are connected to a floating electric plasma supply, thereby establishing a potential difference between the first and the second electric potential; and the vacuum plasma processing apparatus further comprises a negative feedback control loop for controlling at least one of the first electric potential, the second electric potential, the potential difference between the first and the second electric potential.

59. The vacuum plasma processing apparatus of claim 58, wherein, a measured instantaneous dominant entity in the negative feedback control loop consists of or comprises one of the first and the second electric potential relative to a reference potential, and the vacuum plasma processing apparatus comprises a sensing element for the respective first or second electric potential relative to the reference potential.

60. The vacuum plasma processing apparatus of one of claims 58 or 59, wherein, a regulated entity in the negative feedback control loop consists of or comprises at least one of: • a flow of a reactive gas into the vacuum receiver; • the potential difference; and the vacuum plasma processing apparatus comprises an adjustable flow controller for the flow of the reactive gas into the vacuum receiver, and / or an adjustable plasma power supply arrangement for the potential difference between the first and the second plasma electrode.

61. The vacuum plasma processing apparatus of claim 58 or 59, wherein, the first and second plasma electrodes are powered with independently variable electric potentials.

62. The vacuum plasma processing apparatus according to claim 26, wherein the reference potential is a system ground potential.

63. A method of processing a substrate or manufacturing a processed substrate in a vacuum atmosphere with the aid of a plasma generated between a first plasma electrode and a second plasma electrode, comprising: at least one of the first and second plasma electrodes is provided, at least the first plasma electrode comprising an electrode body with an externally patterned surface, the externally patterned surface comprising a first surface area and a second surface area, the first surface area being predominantly coated and the second surface area being predominantly sputtered during the processing, whereby a ratio Q of a sum of the second surface area to a sum of the first surface area is selected to be: 0.1 ≤ Q ≤ 9。 64. The method according to claim 63, the ratio Q being: 0.4 ≤ Q ≤ 1。 65. The method according to claim 63 or 64, carried out by a vacuum plasma processing apparatus according to one of claims 1 to 61.

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