Sputter target for providing a target material for coating a substrate in a sputtering process, combination, sputtering apparatus, and sputtering method

Abstract

The invention relates to a sputter target (8) for providing a target material for coating a substrate (2) in a sputtering process, the sputter target comprising: at least one target body (14) which consists of the target material; and at least one bordering body (15.1, 15.2) which consists of a bordering material different from the target material and adjoins the at least one target body (14), wherein the bordering material has a sputter rate of at most 15% of the sputter rate of the target material and / or the bordering material consists predominantly of carbon, in particular graphite. The invention also relates to: a combination (21) which, in an assembled state, forms a sputter target (8); and a sputtering apparatus (1) and a sputtering method which use the sputter target (8) and / or the combination (21).

Description

[0001] Sputtering target for providing a target material for coating a substrate in a sputtering process, combination, sputtering device and sputtering process

[0002] The content of the German patent application DE 102025 104827.4 is incorporated herein by reference.

[0003] The invention relates to a sputtering target for providing a target material for coating a substrate in a sputtering process. Furthermore, the invention relates to a combination that, in a composite state, forms a sputtering target. The invention also relates to a sputtering device and a sputtering method for coating a substrate.

[0004] From US Patent 2010 / 0300877, a tubular sputtering target is known, comprising a support body, a target body bonded to it, and a rim body designed as a so-called collar. The target body and the rim body are made of a ceramic material, whereby, for such a material combination, the sputtering rate of the rim body material can be slightly lower than that of the target body material. This reduces excessive material removal at the ends of the sputtering target. A disadvantage is that only ceramic target materials can be used, thus limiting application flexibility. Furthermore, the material of the rim body continues to be removed to a significant extent, meaning that both a sputtering device designed with such a sputtering target and the substrate to be coated are exposed to undesirable material ingress.Such a sputtering target is costly to operate, leads to additional maintenance, and can result in reduced coating quality. It is an object of the invention to provide an improved sputtering target for supplying a target material for coating a substrate in a sputtering process, which is particularly flexible and economical in use, and ensures high coating quality.

[0005] This problem is solved by a sputtering target with the features of claim 1. It has been recognized that a sputtering target for providing a target material for coating a substrate in a sputtering process, comprising at least one target body and at least one boundary body, can be designed such that the boundary material has a sputtering rate of at most 15% of the sputtering rate of the target material and / or that the boundary material consists predominantly of carbon, in particular graphite, to promote cost-effectiveness and application flexibility, as well as to ensure a particularly high coating quality. Because the sputtering rate of the boundary material is at most 15% of the sputtering rate of the target material, the area in which the target material is released can be determined with particular precision.This allows for more targeted coating of the substrate, thereby reducing material usage and minimizing unwanted material transfer into the substrate's surroundings. Edge effects, which could lead to uneven material removal, particularly excessive material removal, in the peripheral area of ​​the sputtering target, can be counteracted by the use of at least one boundary material. Using carbon, especially graphite, as the boundary material allows for particularly low sputtering rates. Furthermore, carbon exhibits high electrical conductivity, which positively influences the sputtering process and helps prevent unwanted arcing. The carbon used as a boundary material can also bind oxygen, further preventing oxidation of the target material.The proposed sputtering target is robust and flexible in use, ensures high coating quality and increases the cost-effectiveness of a sputtering process carried out with it through reduced maintenance and material usage.

[0006] A surface of the target body intended for releasing the target material or for sputtering is also referred to as the sputtering surface. The at least one boundary body preferably borders the at least one target body in a top view, particularly directly, and / or contacts it. The at least one boundary body preferably surrounds the at least one target body at least partially, and in particular completely, especially around the sputtering surface.

[0007] The target material refers to the material of the target body. The target material can react, particularly in reactive sputtering, with the process atmosphere, especially oxygen. The resulting reaction product, especially the oxide of the target material, can be deposited onto the substrate. In non-reactive sputtering, essentially the target material is deposited onto the substrate. The sputtering target can be suitable for at least one, and in particular both, of these process types.

[0008] Preferably, the boundary material has a sputtering rate that is lower than the sputtering rate of the target material. In particular, the sputtering rate of the boundary material can be a maximum of 80%, 50%, 20%, 15%, 12%, 10%, 8%, 6%, 2%, and / or at least 0.01%, 0.1%, or 1% of the sputtering rate of the target material. For comparing the sputtering rates, preferably identical sputtering processes, especially process parameters, are used, and / or the boundary material and the target material are used, in particular side-by-side, in the same sputtering process.In particular, sputtering can be carried out using argon ions and / or at a pressure of 1 mPa to 100 mPa, especially from 10 mPa to 50 mPa, and / or at an average kinetic energy of the argon ions of 0.1 keV to 1 keV, especially from.

[0009] The voltages are 0.3 keV to 0.6 keV, particularly 0.5 keV. The average ion current density is preferably in the range of 0.1 mA / cm². 2 up to 10 mA / cm 2 , in particular this can be 1 mA / cm 2 be.

[0010] The at least one boundary body preferably consists of a boundary material that differs from the target material.

[0011] The sputtering rate is preferably determined as the volume removed per unit of time and / or as the thickness of material removed per unit of time or as the height removal rate.

[0012] A static coating rate is preferably defined as the ratio of the layer thickness applied to the substrate per unit time. A dynamic coating rate can be defined as the product of the static coating rate and the coating length. A power-dependent coating rate can also be defined as the ratio of the applied layer thickness per unit length to the sputtering power in watts. Alternatively, any of the aforementioned coating rates can be used instead of the sputtering power.

[0013] The targeting target can have a support body, also referred to as the base body. The at least one target body and / or the at least one boundary body can be attached to the support body, particularly on it, in particular reversibly or permanently, and especially not non-destructively. The attachment can comprise a positive-locking and / or force-locking and / or material-locking connection. Preferably, the at least one target body is positively and / or materially connected to the support body. The at least one boundary body can preferably be force-locked and / or positively connected to the support body.

[0014] The sputer target can have one or more, in particular at least two, in particular at least three, in particular at least four, in particular at least eight, in particular at least ten, in particular at least twenty, in particular at least thirty, in particular at least forty, and / or a maximum of one hundred, in particular at most fifty, in particular at most thirty, in particular at most ten, target bodies and / or boundary bodies. Preferably, the sputer target comprises exactly one target body and / or exactly two boundary bodies.

[0015] The total length of all at least one target body is also referred to as the target length, and the total length of all at least one boundary body is also referred to as the boundary length. Preferably, the target length is greater than the boundary length; in particular, the ratio between the target length and the boundary length is at least 2:1, in particular at least 5:1, in particular at least 10:1, in particular at least 20:1, and / or at most 100:1, in particular at most 60:1, in particular at most 40:1, or vice versa, wherein the boundary length can be correspondingly greater than the target length, for example, for coating small substrates, especially for material testing.

[0016] The support body can be designed as a single piece or in multiple parts. The multiple parts of the support body can be reversibly connected to one another, for example, by means of a screw connection and / or a bayonet connection. In particular, the at least one rim body can be detached from the at least one target body by loosening the multi-part support body. This allows the at least one rim body to be combined with and / or detached from the at least one target body in a particularly time-saving manner and with minimal mechanical stress.

[0017] The boundary material can consist predominantly, i.e., at least 50%, in particular at least 70%, in particular at least 80%, in particular at least 90%, in particular at least 95%, in particular at least 98%, in particular at least 99%, in particular at least 99.5%, in particular at least 99.8%, in particular at least 99.9%, in particular at least 99.98%, of carbon, in particular graphite. The boundary material can consist predominantly, in particular entirely, of carbide. Unless otherwise specified, all percentages relating to material compositions are given in wt.%. The high carbon content ensures a particularly low sputtering rate and high electrical conductivity.Preferably, the at least one boundary body limits and / or surrounds the at least one target body, in particular the sputtering surface, at least partially, and in particular completely, especially in the form of a frame. The at least one boundary body can be arranged between two adjacent target bodies. Alternatively, all target bodies are directly adjacent to one another, in particular without being spatially separated by a boundary body, and / or in contact with one another. The term "adjacent to one another" means in particular that there is a gap, in particular a joining gap, of at most 5 mm, in particular at most 2 mm, in particular at most 1 mm, in particular at most 0.5 mm, in particular at most 0.2 mm, in particular at most 0.1 mm, and / or at least 0.05 mm between them, and in particular that there is contact between them.

[0018] According to one aspect, the at least one boundary body can be reversibly detachable from the at least one target body, particularly via the support body. This allows the boundary body to be reused. A reversibly detachable connection is understood to be a non-destructively detachable connection. This can be force-fit and / or form-fit. The connection is preferably electrically conductive. Alternatively, the at least one boundary body can be permanently, i.e., not non-destructively detachable, from the at least one target body, particularly via the support body.

[0019] Preferably, the sputtering target can be designed as a tubular target. The at least one target body and / or the support body and / or the at least one boundary body can be cylindrical, in particular hollow cylindrical, or tubular. Alternatively, the sputtering target can be designed as a planar target. The tubular target has a central longitudinal axis. Preferably, the length of the tubular target, in particular the support body and / or all of the target bodies, especially along the central longitudinal axis, is in the range of 0.5 m to 6 m, in particular 1 m to 5 m, in particular 1.5 m to 4.5 m, in particular 2 m to 4 m, and in particular approximately 3.8 m to 3.9 m. The outer diameter of the tubular target, in particular in the area of ​​the at least one target body, is in the range of 0.05 m to 0.3 m, in particular 0.1 m to 0.2 m.The inner diameter of the pipe target, in particular the support body, can be in a range of 0.04 m to 0.3 m, in particular from 0.08 m to 0.2 m.

[0020] Preferably, the pipe target is designed for cooling with a cooling fluid. For this purpose, the pipe target can have at least one sealing surface for a liquid-tight closure. The support body can form a liquid-tight pipe wall.

[0021] According to one aspect, the at least one rim body can be ring-shaped. The ring-shaped rim body is also referred to as a "collar." Preferably, the pipe target comprises two ring-shaped rim bodies, preferably one at each pipe end, particularly in the region of the pipe end. The at least one rim body can be hollow cylindrical and / or annular. Preferably, the ring shape is formed by a single, integrally formed rim body. The at least one integral rim body can completely surround the support body. Alternatively, the at least one rim body can be composed of multiple ring segments, wherein, in particular, none of the ring segments completely surrounds the support body.According to one aspect, the boundary material can have a specific electrical resistance that is at most equal to, but in particular lower than, and in particular at least 10% or 50% lower than, that of the target material, or vice versa, such that the specific electrical resistance of the target material is at most equal to, but in particular lower than, and in particular at least 10% or 50% lower than, that of the boundary material. In particular, if the specific electrical resistance of the boundary material is higher than that of the target material, it can be reliably achieved that the introduction of material with higher electrical conductivity into the sputtering device is reduced.

[0022] The boundary material can have a specific electrical resistance of a maximum of 1000 pQm, in particular a maximum of 500 pQm, in particular a maximum of 100 pQm, in particular a maximum of 30 pQm, in particular a maximum of 15 pQm, in particular a maximum of 13 pQm, in particular a maximum of 12 pQm, in particular a maximum of 10 pQm, and / or a resistance of at least 0.1 pQm, in particular a minimum of 1 pQm, especially in at least one spatial direction. This reliably prevents an undesirable arcing effect. Furthermore, a corresponding resistance ensures a high quality or density of the carbon-based boundary material.

[0023] The target material can have a specific electrical resistance of at most 10 pQm, in particular at most 1 pQm, in particular at most 0.1 pQm, in particular at most 0.05 pQm, and / or at least 0.001 pfhn, in particular at least 0.01 pQm, in particular in at least one spatial direction.

[0024] Preferably, when determining the specific electrical resistance and / or the sputtering rate of the target material and / or the boundary material, surface effects, in particular surface oxidation, are neglected. For this purpose, the corresponding properties of the respective material below the surface can be used as a basis.

[0025] The term "sputtering material" preferably refers to the material deposited onto the substrate. The sputtering material can be a reaction product, particularly an oxide, of the target material, or more specifically, a reaction product of the target material and the process atmosphere. The same principles regarding the specific electrical resistance and / or sputtering rate apply to the sputtering material as described for the target material, particularly if the sputtering process is reactive or non-reactive.

[0026] Preferably, the at least one boundary element is manufactured using a pressing process, in particular an isostatic pressing process. This allows for a particularly high quality, especially homogeneity and / or density and / or purity.

[0027] According to one aspect, the sputtering target can have at least one preload force means for exerting a preload force, oriented in particular perpendicular to the sputtering surface and / or radially to the central longitudinal axis, on the at least one target body and / or the at least one boundary body, particularly between the support body and the at least one target body and / or the at least one boundary body. The at least one preload force means preferably comprises a metallic material, in particular it consists of such a material. It can include a spring element, in particular in the form of a bending spring and / or a torsion spring. The spring element can have an arc-shaped cross-section, in particular C-shaped and / or Q-shaped and / or O-shaped. In the longitudinal direction, the spring element can be straight or arc-shaped, in particular annular or ring-segment-shaped and / or helical or helix-shaped.Preferably, the at least one preload force element is positively connected and / or materially connected, in particular by means of a solder, especially comprising indium and / or tin, to the at least one support body and / or the at least one target body and / or the at least one edge body. The soldered connection can be detachable by heat, in particular such that the preload force element and / or the at least one edge body and / or the at least one target body are reusable. For example, the at least one preload force element can be inserted into a groove of the support body and / or the target body and / or the edge body, in particular projecting at least partially, and in particular extending partially, beyond this groove.The at least one preload force means preferably has a thermal conductivity of at least 20 W / mK, in particular at least 40 W / mK, in particular at least 60 W / mK, in particular at least 100 W / mK, in particular at least 200 W / mK, in particular at least 300 W / mK, and / or a maximum of 500 W / mK. The at least one preload force means is preferably positively connected, and more preferably also materially connected, to the support body. The at least one preload force means can interact forcefully with the at least one target body and / or the at least one boundary body. According to one aspect, the target material can consist predominantly of one or more precious metals, in particular silver and / or platinum and / or gold and / or palladium and / or ruthenium and / or iridium and / or rhodium, in particular at least 50%, in particular at least 60%, in particular at least 90%, in particular at least 95%, in particular at least 99%.Alternatively, the target material may consist predominantly of a ceramic, in particular a technical ceramic, for example a nitride and / or carbide and / or boride, and / or predominantly of an oxide ceramic, in particular indium oxide and / or zinc oxide and / or tin oxide and / or titanium oxide and / or niobium oxide and / or tungsten oxide and / or tantalum oxide, and / or predominantly of scandium and / or indium and / or germanium and / or cobalt and / or nickel, in particular at the aforementioned minimum percentage proportions. The target material may be metals, in particular tin and / or zinc, in particular zinc-tin, and / or aluminum, in particular zinc-aluminum, and / or nickel and / or chromium, in particular nickel-chromium, and / or tungsten, in particular tungsten-nickel, and / or tantalum and / or niobium and / or silicon, in particular silicon compounds, and / or scandium, in particular aluminum-scandium, and / or compounds, in particular metals of the 1st, 3rd, 4th, 5th, 6th and / or 8th.The subgroups of the periodic table and / or the 3rd and / or 4th main groups of the periodic table are included, particularly with regard to the aforementioned minimum percentage proportions. The reduced material usage due to the boundary body has a particularly cost-saving effect.

[0028] According to one aspect, the at least one target body can be connected to the support body by a thermal spraying process or reversibly detachable. Preferably, the thermal spraying process ensures the formation of a positive-locking connection, particularly by interlocking or undercutting, especially of mutually contacting surface structures, and / or a material-bonded connection between the at least one target body and the base body. The connection can be supported by chemisorption. This makes the sputtering target particularly economical to manufacture, and in particular, the support body can be designed to be reusable.

[0029] According to another aspect, the material thickness of the at least one rim body can be less than the material thickness of the at least one target body. The low sputtering rate of the rim body allows for corresponding material savings. With a reversibly detachable mounting of the rim body, it can be reused even if its material thickness has already been reduced below that of the target body. In any case, such a sputtering target is particularly material-efficient. The material thickness can be, in particular, a maximum of 80%, a maximum of 60%, a maximum of 40%, and / or a minimum of 10%, or a minimum of 20%, of the material thickness of the at least one target body.

[0030] According to one aspect, the material thickness of the at least one edging element can be at least 1 mm, in particular at least 4 mm, in particular at least 10 mm, in particular at least 15 mm and / or a maximum of 50 mm, in particular a maximum of 40 mm. Such an edging element has a long service life or is reusable.

[0031] According to one aspect, the at least one boundary body can extend over an edge width, particularly in the direction of the central longitudinal axis, of at least 20 mm, in particular at least 30 mm, in particular at least 50 mm, in particular at least 75 mm, in particular at least 100 mm, in particular at least 120 mm, in particular at least 0.5 m, in particular at least 1 m, in particular at least 1.5 m, and / or a maximum of 3 m, in particular a maximum of 1 m, in particular a maximum of 0.6 m, in particular a maximum of 0.4 m, in particular a maximum of 0.3 m, in particular a maximum of 0.2 m. This allows the effects of edge effects, in particular sputter spots with excessive energy input, to be reliably reduced.

[0032] Preferably, the inner diameter of the at least one boundary body is larger, in particular by at least 1 mm, in particular by at least 2 mm, in particular by at least 4 mm, than the inner diameter of the at least one target body. This allows space for the detachable fastening and / or accommodates the lower sputtering rate.

[0033] Another object of the invention is to provide an improved combination which is particularly economical, flexible and robust in use, as well as ensuring a particularly high-quality coating.

[0034] This problem is solved by a combination which, in an assembled state, forms a sputtering target for providing the target material for coating a substrate in a sputtering process, comprising at least one target body made of a target material and at least one boundary body made of a boundary material different from the target material, wherein the at least one boundary body is reversibly detachable in the assembled state from the at least one target body, in particular via a support body, and adjoins the at least one target body. The at least one boundary body preferably has a lower sputtering rate than the at least one target body. The combination can be further developed with at least one of the features described above in connection with the sputtering target.The advantages of this combination preferably correspond to those of the sputtering target described above. Due to the reversibly detachable attachment of the at least one boundary element, it is available for repeated use. The boundary element is particularly reusable because the boundary material preferably has a significantly lower sputtering rate than the target material. This allows for the use of more expensive materials and manufacturing processes for the at least one boundary element, which can ultimately contribute to higher coating quality. The reversibly detachable boundary element can comprise a metallic and / or ceramic and / or organic material. Preferably, the at least one boundary element consists predominantly of carbon, particularly as described above.

[0035] Another object of the invention is to create an improved sputtering device for coating a substrate, which is particularly economical, flexible and robust in operation, and ensures a particularly high coating quality.

[0036] This problem is solved by a sputtering device for coating a substrate, comprising a sputtering chamber, an ion source, a substrate carrier for holding the substrate to be coated, and a sputtering target and / or a combination thereof as described above. The sputtering device may be further developed with at least one of the features described above in connection with the sputtering target and / or the combination. The advantages of the sputtering device preferably correspond to the advantages mentioned above for the sputtering target or the combination.

[0037] The sputtering device preferably includes a vacuum pump, in particular a negative pressure pump, for evacuating the sputtering chamber. The sputtering chamber can be gas-tight, in particular as a negative pressure or vacuum chamber.

[0038] The sputtering chamber is preferably a vacuum chamber.

[0039] The sputtering device can be configured for DC, RF, magnetron, ion beam and / or AC sputtering and / or reactive sputtering.

[0040] Preferably, the ion source comprises an electric field generator and / or a magnetic field generator, also referred to as a magnetron; in particular, the ion source consists of both. The magnetic field generator is preferably arranged at least predominantly, and in particular completely, within the tubular sputtering target.

[0041] A plasma is preferably generated by means of the ion source, particularly within the sputtering chamber. In the sputtering chamber, a plasma is preferably generated or ignited by ionizing the gas, particularly argon, located in and / or introduced into the sputtering chamber. The ions, particularly the argon ions, can be accelerated towards the sputtering target, which preferably acts as the cathode, by the magnetic field generator, particularly the magnetic bar, located at the sputtering target, especially in the tube target. The accelerated ions can eject the target material upon impact with the target surface, particularly mechanically or through the transfer of the ions' kinetic energy to the target material.

[0042] The maximum power output of the sputer device, in particular the ion source, especially when used with the sputer target described above, particularly as the cathode, or the combination thereof, is preferably 40 kW / m, in particular a maximum of 20 kW / m, in particular a maximum of 15 kW / m, and / or at least 1 kW / m, in particular at least 5 kW / m. The power output is preferably specified in kilowatts per meter of length of the sputer target and / or per meter of width of the substrate.

[0043] According to one aspect, the at least one boundary body can be arranged in a sputtering region of the sputtering device, which is also referred to as the effective region of the ion source. The sputtering region is understood to be an area that is irradiated with high-energy ions during sputtering. The sputtering region is preferably limited to an area in which the power input, particularly from the accelerated ions, corresponds to at least 10%, particularly at least 30%, particularly at least 50% of the average power input to the surface of the target body, particularly the sputtering surface. In particular, a surface, especially a surface adjacent to the at least one target body, of the at least one boundary body can be arranged in the sputtering or effective region. This allows the advantageous properties of the boundary body to be utilized particularly comprehensively.

[0044] The at least one boundary body can overlap the magnetic field generator, in particular an arc-shaped boundary region of the magnetic field generator, in an orthogonal projection onto the surface of the substrate and / or a substrate support and / or onto the sputtering surface. In particular, the arc-shaped boundary region of the magnetic field generator can lie at least partially, and in particular completely, within the area of ​​the at least one boundary body, especially when viewed along the central longitudinal axis of the tubular sputtering target. The at least one boundary body preferably surrounds the arc-shaped boundary region at least partially, and in particular completely, such that the arc-shaped boundary region is arranged at least partially, and in particular completely, within a smallest convex envelope of the at least one boundary body.The magnetic field generator is preferably designed in a linear shape with correspondingly arc-shaped edge and end regions. Excessive sputtering power can occur at these arc-shaped end regions. Arranging this region in overlap with the at least one boundary element counteracts excessive material removal.

[0045] According to one aspect, the substrate can be glass, in particular a glass pane, especially a window glass pane, and / or a component of a display and / or a solar cell and / or a sensor and / or a computer chip and / or an electrolyzer, and / or a film, in particular a metal and / or plastic film, and / or a wafer, in particular a silicon wafer, and / or a metal plate and / or a bipolar plate. The target material can contain silver, in particular consist predominantly, in particular entirely, of silver. The term "component" is understood to mean, in particular, parts and / or areas, especially layers.

[0046] Another object of the invention is to provide an improved sputtering process for coating a substrate, which is in particular particularly economical, flexible and robust, and ensures a particularly high-quality coating.

[0047] This problem is solved by a sputtering process for coating a substrate, comprising the steps of: providing a sputtering target and / or a combination as described above, and sputtering the target material onto a surface of the substrate. The sputtering process is preferably further developed with at least one of the features described above in connection with the sputtering target, the combination, and / or the sputtering device. The advantages of the sputtering process preferably correspond to the advantages of the sputtering target, the combination, and / or the sputtering device described above. The sputtering is preferably carried out using high-energy ions, in particular argon ions.The at least one boundary body can be detached from the at least one target body and / or the support body, particularly non-destructively, and / or reused, especially together with at least one other, particularly new, target body. In the sputtering process, the high-energy ions preferably act on the at least one boundary body, at least sectionally, with the same or higher intensity as on the at least one target body. Material removal can occur on the at least one boundary body and on the at least one target body, wherein the material removal in the area of ​​the at least one boundary body preferably corresponds to a maximum of 20%, particularly a maximum of 15%, particularly a maximum of 10%, of the material removal of the at least one target body.

[0048] The sputtering process can be carried out essentially without, or even entirely without, the addition of a reactive gas, or with the addition of a reactive gas, particularly oxygen and / or nitrogen, especially to the sputtering chamber or the atmosphere surrounding the sputtering target. Sputtering without the addition of a reactive gas is also referred to as metallic sputtering. The sputtering target can accordingly be a target for reactive and / or non-reactive sputtering.

[0049] The substrate preferably extends along the central longitudinal axis of the tubular sputtering target over the entire length of all boundary bodies and target bodies, and in particular over the entire length of all target bodies. This prevents unwanted material from entering the environment of the substrate, especially the sputtering device.

[0050] Further features, details and advantages of the invention will become apparent from the following description of an exemplary embodiment with reference to a figure. It shows:

[0051] Fig. 1 shows a schematic representation of a sputtering device for coating a substrate with a target material, comprising a sputtering chamber, an ion source, a substrate carrier for holding the substrate, and a sputtering target for providing the target material.

[0052] Figure 1 describes a sputtering device 1 for coating a substrate 2. The sputtering device 1 is preferably designed as a magnetron sputtering device. Alternatively, the sputtering device 1 can be designed as a DC, RF, ion beam and / or AC sputtering device and / or for reactive sputtering.

[0053] The sputtering device 1 comprises a sputtering chamber 3, an ion source 4, and a substrate carrier 5. The gas pressure in the sputtering chamber 3 is preferably reduced relative to the surroundings, preferably to a maximum of 100 mPa, more particularly to a maximum of 50 mPa, and more particularly to a maximum of 20 mPa. The sputtering device 1 may include a vacuum pump 6 to generate the corresponding reduced pressure relative to the surroundings.

[0054] The sputtering device 1 can be in fluid-conducting communication with an inert gas source 7 for providing an inert gas, in particular argon. The oxygen content present in the sputtering chamber 3 in an operational state is preferably a maximum of 1 wt.%, in particular a maximum of 0.1 wt.%.

[0055] The sputtering chamber 3 is preferably designed to be reversibly closable. For the exchange of the substrate 2, the sputtering chamber 3 can be connected to at least one pressure lock (not shown).

[0056] The ion source is configured to generate an ion flux directed towards a sputtering target 8, in particular to accelerate ions towards the sputtering target 8. For this purpose, the ion source can generate an electric field between the sputtering target 8 (cathode) and an anode, the anode being located on the substrate 2. The substrate 2 can serve as the anode, especially if it is metallic or sufficiently electrically conductive. Alternatively or additionally, one or more separate anodes can be provided.

[0057] Preferably, the ion source includes a magnetic field generator 9, which can also be called a magnetron.

[0058] The substrate carrier 5 is arranged in the sputtering chamber 3 and is designed to carry and / or transport the substrate 2.

[0059] The sputtering target 8 is preferably configured as a tube target. Alternatively, the sputtering target 8 can be configured as a planar target.

[0060] The sputtering device 1 has a target carrier 10 for reversibly and detachably mounting the sputtering target 8 in the sputtering chamber 3. The sputtering device 1 can have a target motor 11 for rotating the tubular sputtering target 8. The target motor 11 is connected to the target carrier 10 in a torque-transmitting manner.

[0061] The magnetic field generator 9 is preferably arranged in a fixed position and / or rotationally fixed position in the sputtering chamber 3.

[0062] The sputtering target 8 can be rotatably arranged relative to the sputtering chamber 3 and / or the magnetic field generator 9 and / or the substrate carrier 5, in particular rotatably by means of the target motor 11. The sputtering target 8 is described in more detail below. The sputtering target 8 preferably comprises a support body 12, which is preferably tubular, in particular hollow cylindrical.

[0063] The support body 12 can generally be made of a metallic material, for example stainless steel and / or titanium and / or copper, especially in the case of a tubular sputtering target 8, and / or titanium and / or copper and / or molybdenum, especially in the case of a planar sputtering target or a planar target, and in particular consist of such material.

[0064] The sputtering target 8 and / or the support body 12 can have a length L of 0.3 m to 6 m, in particular of 0.5 m to 5 m, in particular of 1 m to 4 m, in particular of 2 m to 3 m, wherein the aforementioned range limits are preferably arbitrarily combinable with one another. The length L preferably corresponds to an axial dimension parallel to a central longitudinal axis 13 of the tubular sputtering target 8.

[0065] The inner diameter d of the sputtering target 8 and / or the support body 12 can be in the range of 0.05 m to 0.25 m, and in particular 0.125 m. The wall thickness tc of the support body 12 can preferably be in the range of 2 mm to 20 mm, and in particular 4 mm.

[0066] The sputtering target 8 comprises at least one, in particular one or more, target bodies 14 and at least one, preferably several, in particular two, boundary bodies 15.1, 15.2.

[0067] The target body 14 can be permanently, and in particular irremovably, or non-destructively releasable, connected to the support body 12. In particular, the target body 14 can be bonded to the support body 12 by a material bond. Preferably, the target body 14 is applied to the support body 12 by a thermal spraying process, in particular such that a positive-locking connection is established between them. Preferably, the support body 12 has an adhesion promoter, in particular an adhesive layer, which provides a surface with a high roughness. With such an adhesion promoter, the target body can form a particularly robust positive-locking connection.

[0068] The length LT of the target body 14 can be in a range of 0.5 m to 6 m, in particular from 1 m to 5 m, and in particular from 3 m to 4 m.

[0069] The target body 14 can have an outer diameter DT in a range of 0.1 m to 0.25 m, in particular 0.16 m.

[0070] The material thickness of the target body 14 can be essentially constant, particularly along the central longitudinal axis 13, and / or be in a range of 2 mm to 50 mm, particularly 5 mm to 40 mm, and particularly 10 mm to 20 mm.

[0071] The target body 14 comprises the target material intended for coating the substrate 2; in particular, the target body 14 consists of this material. The target material can be, in particular, a metallic, ceramic, and / or organic material. Preferably, the target body 14 consists predominantly, in particular to at least 70%, in particular to at least 90%, in particular to at least 95%, in particular to at least 99%, of a precious metal, for example, gold, silver, platinum, and / or palladium. Alternatively, the target body 14 can consist predominantly, in particular entirely, of a technical ceramic, for example, a nitride, carbide, and / or boride, and / or of an oxide ceramic, and / or of another material as described above.

[0072] The two boundary bodies 15.1, 15.2 can be essentially identical.

[0073] The at least one boundary body 15.1, 15.2 is preferably ring-shaped, in particular hollow cylindrical. The ring-shaped boundary body 15.1, 15.2 is also referred to as a collar.

[0074] The support body 12 is preferably attached to the at least one edge body 15.1, 15.2 in a reversibly detachable or non-destructive manner. The attachment of the at least one edge body 15.1, 15.2 to the support body 12 can be positive-locking and / or force-locking.

[0075] For force-fit fastening, the sputtering target 8 can have at least one prestressing force means 16 to effect a prestressing force between the support body 12 and the at least one boundary body 15.1, 15.2, oriented in particular perpendicular to a sputtering surface 17 and / or radially to the central longitudinal axis 13.

[0076] The at least one preload force means 16 can comprise a spring, in particular a bending spring, especially a leaf spring. In cross-section, the at least one preload force means 16 can be O-shaped and / or C-shaped and / or Omega-shaped. The at least one preload force means 16 can extend around the support body 12 in an arc-shaped, in particular helical or helix-shaped manner. In particular, the at least one preload force means 16 can be arranged in at least one corresponding recess 18, in particular a groove. The at least one preload force means 16 can be positively engaged in the recess 18.

[0077] The prestressing force element 16 can be metallurgically bonded to the supporting body 12 and / or to the at least one boundary body 15.1, 15.2, in particular by means of a solder, especially one comprising indium and / or tin. This can improve the thermal conductivity and / or the strength.

[0078] The respective edge body 15.1, 15.2 can be axially pushed onto the support body 12, in particular onto the at least one prestressing force means 16. The prestressing force secures the at least one edge body 15.1, 15.2 to the support body 12.

[0079] Preferably, the preload force means 16 comprises a material with a thermal conductivity of at least 10 W / mK, in particular at least 20 W / mK, in particular at least 40 W / mK, in particular at least 100 W / mK, and / or a maximum of 500 W / mK.

[0080] The at least one boundary body 15.1, 15.2 preferably borders directly on the target body 14. In particular, the at least one boundary body 15.1, 15.2 can border the sputtering surface 17, especially in a top view of the sputtering surface 17. In other words, a boundary surface 15.1, 15.2 of the respective boundary body 15.1, 15.2 can border the sputtering surface 17.

[0081] The at least one boundary body 15.1, 15.2 may have a boundary material which consists largely, in particular to a predominant extent, in particular to at least 70%, in particular to at least 90%, in particular to at least 95%, in particular to at least 99%, in particular to at least 99.9%, in particular to at least 99.98%, of carbon and / or graphite.

[0082] Particularly preferably, the at least one boundary body 15.1, 15.2 consists of a material with a specific electrical resistance of at most 100 pQm, in particular at most 50 pQm, in particular at most 15 pQm, and / or at least 0.1 pQm, in particular at least 1 pQm. This avoids an undesirable "arcing" effect during the sputtering process.

[0083] The boundary material preferably has a lower sputtering rate than the target material. The ratio between the sputtering rates of the target material and the boundary material is preferably at least 6:1, particularly at least 10:1, and especially at least 12:1. The sputtering rates are preferably determined under identical sputtering conditions for both materials, particularly at the pressure specified above and with argon as the ionization gas. In particular, the average kinetic energy of the argon ions can be 0.1 to 1 keV.

[0084] The length LB of the boundary body 15.1, 15.2, in particular along the central longitudinal axis 13, can be in a range of 0.02 m to 0.4 m, in particular from 0.1 m to 0.3 m, and in particular be 0.15 m. The material thickness tß of the at least one boundary body 15.1, 15.2 can be less than, equal to or greater than the material thickness t of the target body 14, in particular in a range of 1 mm to 50 mm, in particular from 2 mm to 25 mm, in particular from 5 mm to 20 mm, and in particular be 10 mm.

[0085] The outer diameter DB of the boundary body 15.1, 15.2 can be in a range of 0.1 m to 0.25 m, in particular from 0.12 m to 0.2 m.

[0086] As an alternative to the material-bonded connection of the target body 14 with the support body 12, a reversibly detachable connection between them can be provided, in particular by means of a prestressing force means 16, as described above in connection with the fastening of the boundary body 15.1, 15.2.

[0087] A sputtering area is essentially defined by the length of the magnetic field generator 9 in the sputtering target 8, particularly in the target body 14. An effective area of ​​the ion source preferably overlaps the at least one boundary body 15.1, 15.2. The effective area is preferably understood to be at least that area which, in a top view of the sputtering surface 17 and / or the substrate 2, is overlapped by the ion source, particularly the magnetic field generator 9. The effective area is also referred to as the sputtering area.

[0088] The magnetic field generator 9 can be configured as a linear path. In a top view of the substrate 2 and / or the sputtering surface 17, the single-arc-shaped end section 20.1, 20.2 of the magnetic field generator 9 can overlap, at least partially, and in particular completely, with the at least one boundary body 15.1, 15.2. This prevents ionization spots and / or sinks on the arc-shaped end section 20.1, 20.2 from leading to increased or decreased removal of the target material.

[0089] The substrate may be glass, in particular a glass pane, especially window glass and / or display glass, and / or a component of a display, a solar cell, a sensor and / or a computer chip and / or an electrolyzer, and / or a film, in particular a metal and / or plastic film, and / or a wafer, in particular a silicon wafer, and / or a metal plate and / or a bipolar plate.

[0090] The at least one target body 14 together with the at least one boundary body 15.1, 15.2 reversibly detachable from the target body 14, in particular together with the support body 12, can form a combination 21.

[0091] The operation of the sputtering device 1, the sputtering target 8 or the combination 21 is as follows:

[0092] The sputtering target 8 is arranged in the sputtering device 1, in particular in the sputtering chamber 3, and is attached to the target carrier 10. The sputtering target 8 is a composite assembly 21, wherein the boundary bodies 15.1, 15.2 are attached to the support body 12 by means of the respective preload means 16. The substrate 2 is placed in the sputtering chamber 3 and arranged on the substrate carrier 5.

[0093] Sputtering chamber 3 is closed. The vacuum pump 6 is used to evacuate sputtering chamber 3.

[0094] Inert gas, in particular argon, can be introduced into the sputtering chamber 3 via the inert gas source 7. The sputtering device 1 is ready for use.

[0095] The ion source is activated, thereby generating an electric field between the sputtering target 8 and the anode. A magnetic field can be generated by means of the magnetic field generator 9. An ion current, comprising argon ions, is generated, which, particularly due to the magnetic field, is oriented towards the sputtering target 8, especially the target body and the at least one boundary body 15.1, 15.2.

[0096] The high-energy ions remove target material from the target body 14, which in particular transitions into the gas phase and is deposited on the substrate surface 22. The target material thus forms a coating 23 on the substrate surface 22.

[0097] In the area of ​​the boundary bodies 15.1, 15.2, sputtering of material is undesirable, since a large part of the material released in this area would not reach the substrate 2, but would enter the sputtering chamber 3 and be deposited on components of the sputtering device 1.

[0098] Because the boundary bodies 15.1, 15.2 have a significantly lower sputtering rate than the target body 14, material release in the boundary regions is avoided. In particular, this prevents ionization spots in the region of the arc-shaped end sections 20.1, 20.2 of the magnetic field generator 9 from leading to increased material release. This protects the sputtering device 1 from unwanted material input and saves target material.

[0099] During the sputtering process, the sputtering target 8 is rotated around the central longitudinal axis 13, in particular by means of the target motor 11. This ensures a uniform removal of the target material.

[0100] The sputtering target 8 can be replaced if the target body 14 is worn down, in particular if it falls below a minimum material thickness and / or if the target body 14 has an uneven surface.

[0101] Due to the significantly lower sputtering rate of the boundary bodies 15.1, 15.2, they can still be used even after the at least one target body 14 has been consumed. The reversibly detachable fastening ensures that the at least one boundary body 15.1, 15.2 can be reused. For this purpose, a new target body 14, in particular mounted on a support body 12, can be provided. The boundary bodies 15.1, 15.2 can be connected to the new target body 14, in particular by means of the preload force device 16.

[0102] The at least one boundary body 15.1, 15.2 can be used multiple times, in particular until a certain minimum material thickness is reached. For example, the at least one boundary body 15.1, 15.2 can be reused at least once, in particular at least twice, in particular five times, in particular ten times and / or a maximum of 100 times, in particular a maximum of 50 times. The sputtering device 1, the sputtering target 8, the combination 21, and the method ensure the coating of a substrate 2 in a particularly material-saving, economical, robust, and time-efficient manner. The material input into the sputtering device 1 is reduced. Time-consuming and costly cleaning of the sputtering device 1 can thus be avoided. Losses of target material, especially costly material, are reduced. The service life of the sputtering device 1 is extended. The reusability of the at least one boundary body 15.1, 15.2 is ensured.2 further increases efficiency. The more targeted release of the sputer material improves the coating quality.

Claims

Patent claims 1. Sputtering target (8) for providing a target material for coating a substrate (2) in a sputtering process, comprising 1.1 at least one target body (14) consisting of the target material, and 1.2 at least one boundary body (15.1, 15.2) which consists of a boundary material different from the target material and to which the at least one target body (14) adjoins, characterized in that 1.3.1 the boundary material has a sputtering rate of no more than 15% of the sputtering rate of the target material and / or 1.3.2 the edging material consists predominantly, i.e. at least 50 wt.%, of carbon, in particular graphite.

2. Sputter target (8) according to claim 1, characterized in that the boundary body (15.1, 15.2) is reversibly detachable from the target body (14), in particular via a support body (12).

3. Sputter target (8) according to claim 1 or 2, characterized in that it is designed as a tube target.

4. Sputter target (8) according to one of the preceding claims, characterized in that the at least one boundary body (15.1, 15.2) is annular.

5. Sputter target (8) according to one of the preceding claims, characterized in that the specific electrical resistance of the target material is lower than the specific electrical resistance of the boundary material.

6. Sputter target (8) according to one of the preceding claims, characterized in that the boundary material has a specific electrical resistance of a maximum of 100 pQm, in particular a maximum of 15 pQm.

7. Sputter target (8) according to one of the preceding claims, characterized by at least one prestressing force means (16) for effecting a prestressing force, in particular oriented perpendicular to a sputtering surface (17) and / or radially to a central longitudinal axis (13) of the sputter target (8), between a support body (12) and the at least one target body (14) and / or the at least one boundary body (15.1, 15.2).

8. Sputter target (8) according to one of the preceding claims, characterized in that the target material consists predominantly of one or more precious metals, in particular silver and / or platinum, and / or gold and / or palladium and / or ruthenium and / or iridium and / or rhodium, and / or predominantly of a nitride and / or a carbide and / or a boride and / or a ceramic and / or predominantly of scandium and / or indium and / or germanium and / or cobalt and / or nickel.

9. Sputter target (8) according to one of the preceding claims, characterized in that the at least one target body (14) is attached to a support body (12) in a thermal spraying process or reversibly detachable.

10. Sputter target (8) according to one of the preceding claims, characterized in that a material thickness (tß) of the at least one boundary body (15.1, 15.2) is less than a material thickness (fr) of the at least one target body (14).

11. Sputter target (8) according to one of the preceding claims, characterized in that a material thickness (tß) of the at least one boundary body (15.1, 15.2) is at least 1 mm, in particular at least 4 mm, in particular at least 10 mm.

12. Sputter target (8) according to one of the preceding claims, characterized in that the at least one boundary body (15.1, 15.2) extends over a boundary width (LB) of at least 20 mm.

13. Combination (21) which in a composite state forms a sputtering target (8) for providing a target material for coating a substrate (2) in a sputtering process, comprising 13.1 at least one target body (14) consisting of a target material, and 13.2 at least one boundary body (15.1, 15.2) consisting of a boundary material different from the target material, 13.3 wherein the at least one boundary body (15.1, 15.2) in the composite state adjoins the at least one target body (14) and is reversibly detachable connected to the at least one target body (14), in particular via a support body (12).

14. Sputtering device (1) for coating a substrate (2), comprising 14.1 a sputtering chamber (3), 14.2 an ion source, 14.3 a substrate carrier (5) for carrying the substrate (2) to be coated and 14.4 a sputtering target (8) and / or a combination according to any one of claims 1 to 13.

15. Sputtering device (1) according to claim 14, characterized in that the at least one boundary body (15.1, 15.2) is arranged in a sputtering area of ​​the sputtering device (1).

16. Sputtering device (1) according to claim 14 or 15, characterized in that the substrate (2) is a glass, in particular a glass sheet, and / or a component of a display and / or a solar cell and / or a sensor and / or a computer chip and / or an electrolyzer, and / or a film, in particular a metal and / or plastic film, and / or a wafer, in particular a silicon wafer, and / or a metal plate and / or a bipolar plate.

17. Sputtering process for coating a substrate (2), comprising the steps: 17.1 Providing a sputtering target (8) and / or a combination (21) according to any one of claims 1 to 13, 17.2 Sputtering the target material onto a surface (22) of the substrate (2).

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