TECHNICAL FIELD [0001] Embodiments of the present invention relate to layer deposition by sputtering from a target. Embodiments of the present invention particularly relate to sputtering on large area substrates, more particularly for static deposition processes. Embodiments relate specifically to an apparatus and a method for depositing a layer of a material on a substrate.

BACKGROUND

[0002] In many applications, deposition of thin layers on a substrate, e.g. on a glass substrate is desired. Conventionally, the substrates are coated in different chambers of a coating apparatus. For some applications, the substrates are coated in a vacuum, using a vapor deposition technique.

[0003] Several methods are known for depositing a material on a substrate. For instance, substrates may be coated by a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process or a plasma enhanced chemical vapor deposition (PECVD) process etc. Usually, the process is performed in a process apparatus or process chamber where the substrate to be coated is located. For a PVD process, the deposition material can be present in the solid phase in a target. By bombarding the target with energetic particles, atoms of the target material, i.e. the material to be deposited, are ejected from the target. The atoms of the target material are deposited on the substrate to be coated. In a PVD process, the sputter material, i.e. the material to be deposited on the substrate, may be arranged in different ways. For instance, the target may be made from the material to be deposited or may have a backing element on which the material to be deposited is fixed. The target including the material to be deposited is supported or fixed in a predefined position in a deposition chamber.

[0004] Typically, sputtering can be conducted as magnetron sputtering, wherein a magnet assembly is utilized to confine the plasma for improved sputtering conditions. The plasma distribution, the plasma characteristics and other deposition parameters need to be controlled in order to obtain a desired layer deposition on the substrate. For example, a uniform layer with desired layer properties is desired. This is particularly beneficial for large area deposition, e.g. for manufacturing displays on large area substrates. Further, uniformity and process stability can be particularly difficult to achieve for static deposition processes, wherein the substrate is not moved continuously through a deposition zone. Accordingly, considering the increasing demands for the manufacturing of opto-electronic devices and other devices on a large scale, process uniformity and/or stability needs to be further improved.

[0005] In conventional large area multi target static PVD array coaters, several sputter targets are used to cover the complete substrate area. The distribution of sputtered material from one target is usually spread over a broad area and also contributes to the coating deposition in a region of the next two or more neighboring targets. At the edge of the substrate this contribution from neighboring targets is missing, which results in a thickness drop of the coating at the edge of the substrate.

[0006] Accordingly, there is a desire to improve PVD deposition, particularly on edges of large area substrates.

SUMMARY

[0007] In light of the above, an apparatus and a method for depositing a layer of a material on a substrate according to the independent claims are provided. Further aspects, advantages, and features are apparent from the dependent claims, the description and the accompanying drawings. [0008] According to one embodiment, an apparatus for deposition of material on a substrate is provided. The apparatus includes a deposition array having three or more cathodes. The deposition array includes a first outer deposition assembly comprising at least a first cathode of the three or more cathodes, a second outer deposition assembly opposing the first outer deposition assembly comprising at least a second cathode of the three or more cathodes, and an inner deposition assembly comprising at least one inner cathode located between the first outer deposition assembly and the second outer deposition assembly. At least one of the first outer deposition assembly and the second outer deposition assembly is configured for depositing the material at a higher rate than the inner deposition assembly on the same substrate during the same time.

[0009] According to a second embodiment, an apparatus for deposition of material on a substrate is provided. The apparatus includes a deposition array having three or more cathodes. The deposition array includes a first outer deposition assembly comprising at least a first cathode of the three or more cathodes, a second outer deposition assembly opposing the first outer deposition assembly comprising at least a second cathode of the three or more cathodes, and an inner deposition assembly comprising at least one inner cathode located between the first outer deposition assembly and the second outer deposition assembly. The first outer deposition assembly defines a first edge section in a substrate transport direction and the second outer deposition assembly defines a second edge section opposing the first edge section in substrate transport direction, wherein the deposition array further includes a third edge section including first ends of the at least one inner cathode of the inner deposition assembly and a forth edge section including opposing second ends of the cathodes of the inner deposition assembly of the cathode array. The gas distribution system is configured for providing a first processing gas condition to the first edge section, the second edge section, the third edge section and the forth edge section for depositing the material at a higher rate than in the remaining section located between the first edge section, the second edge section, the third edge section and the forth edge section.

[0010] According to another embodiment, a method for deposition of material on a substrate is provided. The method includes providing a deposition array having three or more cathodes, wherein the deposition array includes a first outer deposition assembly comprising at least a first cathode of the three or more cathodes, a second outer deposition assembly opposing the first outer deposition assembly comprising at least a second cathode of the three or more cathodes, and an inner deposition assembly comprising at least one inner cathode located between the first outer deposition assembly and the second outer deposition assembly, and depositing material on the substrate with the at least one of the first outer deposition assembly and the second outer deposition assembly at a higher rate than with the inner deposition assembly.

[0011] According to yet another embodiment, a method for deposition of material on a substrate is provided. The method includes providing a deposition array having three or more cathodes, wherein the deposition array includes a first outer deposition assembly comprising at least a first cathode of the three or more cathodes, a second outer deposition assembly opposing the first outer deposition assembly comprising at least a second cathode of the three or more cathodes, and an inner deposition assembly comprising at least one inner cathode located between the first outer deposition assembly and the second outer deposition assembly. The first outer deposition assembly defines a first edge section in a substrate transport direction and the second outer deposition assembly defines a second edge section opposing the first edge section in substrate transport direction, wherein the deposition array further comprises a third edge section including first ends of the at least one inner cathode of the inner deposition assembly and a forth edge section including opposing second ends of the cathodes of the inner deposition assembly of the cathode array, wherein depositing material on the substrate further includes depositing material at the first edge section, the second edge section, the third edge section and the forth edge section at a higher rate than in the remaining section located between the first edge section, the second edge section, the third edge section and the forth edge section.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the invention and are described in the following: shows a schematic view of an apparatus for deposition of material on a substrate, according to embodiments described herein; shows a schematic view of an apparatus for deposition of material on a substrate, according to embodiments described herein; shows a schematic cross-sectional view of an apparatus having a rotary cathode array configuration according to embodiments described herein, wherein the array is supplied by AC power supplies, and wherein a controller for controlling at least one process parameter is provided; shows a schematic cross-sectional view of an apparatus having a rotary cathode array configuration according to embodiments described herein, wherein the array is supplied by DC power supplies, and wherein a controller for controlling at least one process parameter is provided; shows a schematic cross-sectional view of a rotary cathode according to embodiments described herein, wherein an eccentric arrangement configured for varying the position of the magnetic assembly in relation to the cathode is shown in a first position; shows a schematic cross-sectional view of a rotary cathode according to embodiments described herein, wherein an eccentric arrangement configured for varying the position of the magnetic assembly in relation to the cathode is shown in a second position; shows a schematic view of an apparatus for deposition of material on a substrate, according to embodiments described herein; according to embodiments described herein; shows a flow chart illustrating a method for deposition of material on a substrate, according to embodiments described herein. DETAILED DESCRIPTION OF EMBODIMENTS

[0013] Reference will now be made in detail to the various embodiments of the invention, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. In the following, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the invention and is not meant as a limitation of the invention. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

[0014] According to embodiments described herein, with exemplary reference to Fig. 1, an apparatus 100 for deposition of material on a substrate including a deposition array 222 having three or more cathodes is provided. The deposition array 222 includes a first outer deposition assembly 301 comprising at least a first cathode of the three or more cathodes, a second outer deposition assembly 302 opposing the first outer deposition assembly comprising at least a second cathode of the three or more cathodes, and an inner deposition assembly 303 comprising at least one inner cathode located between the first outer deposition assembly and the second outer deposition assembly. At least one of the first outer deposition assembly and the second outer deposition assembly is configured for depositing the material at a higher rate than the inner deposition assembly on the same substrate during the same time, as exemplarily shown in the graph at the bottom of Fig. 1, in which the deposition rate DR is plotted over the distance between the first outer deposition assembly 301 and the second outer deposition assembly 302. As illustrated in the graph at the bottom of Fig. 1, in the exemplary embodiment of Fig. 1, both the first outer deposition assembly 301 and the second outer deposition assembly 302 are configured for depositing the material at a higher rate than the inner deposition assembly.

[0015] Therefore, by providing an apparatus having outer deposition assemblies configured for depositing the material at a higher rate than the inner deposition assembly, a thickness drop at the substrate edges in transport direction can substantially be avoided. Hence, the apparatus as described herein allows for deposition of uniform coatings on substrates, particularly on large area substrates during static deposition processes. [0016] In the present disclosure, and not limited to any specific embodiment described herein, the term "deposition rate" or "depositing rate" may be understood as the amount of coating material deposited on the substrate per unit time.

[0017] In the present disclosure, and not limited to any specific embodiment described herein, a deposition array includes a plurality of deposition assemblies, particularly at least three deposition assemblies. The plurality deposition assemblies may be arranged adjacent to each other. Particularly, the plurality of deposition assemblies may be arranged parallel to each other, for example parallel with an equal spacing between neighboring deposition assemblies. [0018] In the present disclosure, and not limited to any specific embodiment described herein, a deposition assembly may include at least one deposition source for deposition of material on a substrate, such as a target. The deposition assembly may include at least one selected from the group consisting of: a gas distribution system, a cathode, particularly a rotary cathode, a power supply, a magnet assembly, and means for controlling at least one processing parameter. The means for controlling at least one processing parameter can, for example, include a controller for controlling a power supply of a deposition assembly and/or a mass flow controller for controlling an amount of processing gas to a deposition assembly and/or an element for controlling the magnetic field of a magnet assembly, such as an eccentric arrangement. The eccentric arrangement may be configured for varying the position of the magnetic assembly in relation to the cathode.

[0019] According to different embodiments, which can be combined with other embodiments described herein, sputtering can be conducted as DC (direct current) sputtering, MF (middle frequency) sputtering, as RF sputtering, or as pulse sputtering. As described herein, some deposition processes might beneficially apply MF, DC or pulsed sputtering. However, other sputtering methods can also be applied. According to embodiments herein, middle frequency is a frequency in the range of 0.5 kHz to 350 kHz, for example, 10 kHz to 50 kHz.

[0020] According to some embodiments, which can be combined with other embodiments described herein, the sputtering according to the described embodiments can be conducted with three or more cathodes. However, particularly for applications for large area deposition, an array of cathodes having 6 or more cathodes, e.g. 10 or more cathodes. For example, three or more cathodes or cathode pairs, e.g. four, five, six or even more cathodes or cathode pairs can be provided. The array can be provided in one vacuum chamber. Further, an array can typically be defined such that adjacent cathodes or cathode pairs influence each other, e.g. by having interacting plasma confinement. According to typical implementations, the sputtering can be conducted by a rotary cathode array, such as, but not limited to, a system such as PiVot of Applied Materials Inc..

[0021] According to yet further typical embodiments, which can be combined with other embodiments described herein, static deposition of material on a substrate is done by a reactive sputter process. That means, the stoichiometry of the film is obtained by sputtering either metallic, semi-metallic or compound targets using a mixture of non-reactive gas and reactive gases. Typically, embodiments described herein may also be suitable for static deposition of metal layers or semiconducting layers using only non-reactive gas as processing gas. In this case, the apparatus and method of embodiments of the present invention may allow having different local process pressure along the horizontal direction, particularly different process pressure at the substrate edges compared to the inner areas of the substrate.

[0022] Accordingly, some embodiments described herein relate to apparatus and methods of depositing a layer of a material on a substrate. Particularly for reactive sputtering processes, uniformity and/or plasma stability is a critical parameter to be considered. Reactive sputtering processes, for example, deposition processes during which a material is sputtered under oxygen atmosphere or another reactive atmosphere in order to deposit a layer containing an oxide or the like of the sputtered material, need to be controlled with respect to plasma stability. Typically, a reactive deposition process has a hysteresis curve. The reactive deposition process can be, for example, a deposition of aluminum oxide (A1203) or silicon oxide (Si02) or Indium-Gallium-Zinc-Oxide (IGZO), wherein aluminum, silicon, indium, gallium or zinc are sputtered from a cathode while oxygen is provided in the plasma. For example, aluminum oxide, silicon oxide or Indium- Gallium-Zinc-Oxide can be deposited on a substrate. The hysteresis curve typically is a function of deposition parameters such as the voltage provided to the sputter cathode in dependence of the flow of a processing gas, such as oxygen. [0023] Embodiments described herein allow for improved uniformity in the event different plasma density or different reactive gas consumption at different positions along the substrate transport direction, referred to as horizontal direction hereinafter, exist during static reactive sputter processes. These differences also result in a non-uniform deposition on the substrates. Embodiments described herein allow compensating a variation of film properties in horizontal direction, i.e. substrate transport direction or the direction perpendicular to the rotation axis of rotary cathodes. Hence, embodiments as described herein are particularly configured for providing a uniform coating on the complete substrate, i.e. including the substrate edges in transport direction of the substrate. [0024] According to embodiments described herein, which can be combined with other embodiment described herein, the partial pressure of at least one of the processing gases is different at the first outer deposition assembly and or the second outer deposition assembly along the horizontal direction, i.e. along the substrate transport direction. For example, the partial pressure of the reactive gas (e.g. oxygen) is varied. It is further possible that the pressure of a second processing gas, e.g. a non-reactive or inert gas is additionally varied. Accordingly, the overall pressure can be essentially constant.

[0025] According to typical embodiments, processing gases can include non-reactive gases such as argon (Ar) and/or reactive gases such as oxygen (02), nitrogen (N2), hydrogen (H2), water (H20), ammonia (NH3), Ozone (03), activated gases or the like. [0026] It has been found that for static deposition processes, film properties may vary in a plurality of ways leading to non-uniformities. With the above-mentioned designs and processes it is not possible to compensate any variation of film properties in the horizontal direction, particularly at the edges of the substrate to be coated. In order to be able to compensate for local differences in film properties in the horizontal direction for static deposition, particularly the edges of the substrate embodiments of the present invention provide an apparatus and a method with which a uniform film thickness over the substrate including the substrate edges in transport direction can be achieved. Therefore, according to embodiments which can be combined with other embodiments herein, as exemplarily shown in FIG. 2, a gas distribution system is provided which is configured for supplying different processing gas conditions to the first outer deposition assembly and/or the second outer deposition assembly. [0027] Referring to FIG. 2, an apparatus for deposition of material on a substrate having a deposition array 222 including a first outer deposition assembly 301 with at least a first cathode 122 and a second outer deposition assembly 302 opposing the first outer deposition assembly 101 with at least a second cathode 122 is shown. Further, according to embodiments described herein, an inner deposition assembly 303 including at least one inner cathode 122 located between the first outer deposition assembly 301 and the second outer deposition assembly 302 is provided. In the exemplary embodiment as shown in FIG.2 each of the first outer deposition assembly 301 and second outer deposition assembly 302 includes one cathode, wherein the inner deposition assembly 301 includes ten cathodes.

[0028] According to embodiments described herein, the apparatus includes a processing gas distribution system configured for providing a processing gas to the deposition array 222. Particularly, as exemplarily shown in FIG. 2, the gas distribution system may be configured for controlling the flow rate of processing gas independently for the outer deposition assemblies 301, 302 and the inner deposition assembly 303. Therefore, process parameters, e.g. partial gas pressure and/or amount of processing gas supplied, at the edges of a substrate to be coated can be modified and adjusted independently from process parameters at the inner area of the substrate to be coated, such that a uniform thickness of a coating may be achieved. Accordingly, thickness drops at the edges of the substrate in transport direction can substantially be avoided. In FIG. 2 the substrate transport direction is indicated by arrow 111. This is particularly beneficial for deposition processes wherein the substrate is positioned for a static deposition process. According to some embodiments, which can be combined with other embodiments described herein, the flow rate of at least one processing gas can be varied independently for at least one of the first outer deposition assembly and the second outer deposition assembly, e.g. by MFCs as exemplarily shown in FIG. 2.

[0029] According to embodiments described herein, the processing gas distribution system is configured for providing a first processing gas condition to the first outer deposition assembly 301 and the second outer deposition assembly 302 and for providing a second processing gas condition to the inner deposition assembly 303. With exemplary reference to FIG. 2, according to embodiments as described herein, the apparatus includes a gas distribution system configured for providing a processing gas with 3-fold horizontal segmentation, wherein the a first segment includes the first outer deposition assembly 301, a second segment includes the second outer deposition assembly 302, and a third segment includes the inner deposition assembly 303. The gas distribution system may include multiple gas inlet points 138 within multiple gas lines 116. The multiple gas lines 116, e.g. conduits having openings therein, can be placed between pairs of cathodes 122 of the deposition array 222, parallel to their longitudinal axes along the horizontal direction.

[0030] According to embodiments described herein, the gas distribution system may include a first mass flow controller 234 configured for controlling the amount of processing gas to the first outer deposition assembly 301 and the second outer deposition assembly 302, and a second mass flow controller 134 configured for controlling the amount of processing gas to the inner deposition assembly 303. In the exemplary embodiment of FIG. 2, three MFCs are shown: one second MFC 134 for controlling the amount of processing gas to the inner deposition assembly 303 and two first MFCs 234 for controlling the amount of processing gas to the first outer deposition assembly 301 and to the second outer deposition assembly 302, respectively. According to embodiments, the two first MFCs 234 for controlling the amount of processing gas to the first outer deposition assembly 301 and second outer deposition assembly 302 may be equal. Alternatively, the two MFCs 234 for controlling the amount to the first outer deposition assembly 301 and second outer deposition assembly 302 may be configured differently.

[0031] As exemplarily shown in FIG. 2, the processing gas distribution system may have two gas tanks 136 containing processing gas. The flow rates and/or the amount of non- reactive gas and/or reactive gas present in the processing gas may be controlled by MFCs 135. The processing gas is fed to multiple gas inlet points 138 within multiple gas lines 116 through gas conduits or gas pipes 133 and 233 via MFCs 134 and 234, respectively. According to yet further embodiments, which can be combined with other embodiments described herein, the flow rate of one or more of the processing gases, i.e. the amount of one or more of the processing gases, can also be controlled by another flow rate control element, such as a needle valve. Accordingly, MFCs, needle valves, and/or other flow rate control elements can be used to control the flow rate of one or more processing gases independently for segments of the gas distribution system or the amount of one or more processing gases independently for segments of the gas distribution system.

[0032] According to embodiments which can be combined with other embodiments described herein, the gas distribution system may be configured for providing different processing gas mixtures, especially with a variation of reactive gases, to the first outer deposition assembly 301 and the second outer deposition assembly 302 compared to the inner deposition assembly. Therefore, with exemplary reference to FIG. 3A, the first outer deposition assembly 301 may be connected to a first group of tanks 141 for providing a first composition of reactive gases, the second outer deposition assembly 302 may be connected to a second group of tanks 142 for providing a second composition of reactive gases, and the inner deposition assembly may be connected to a third group 143 of tanks for providing a third composition of reactive gases to the inner deposition assembly. According to embodiments, the first composition of reactive gases supplied to the first outer deposition assembly 301 may correspond to the second composition of reactive gases supplied to the second outer deposition assembly 302. Therefore, embodiments of the apparatus, as exemplarily shown in FIG. 3A, are configured for providing a different flow rate of processing gas and/or different amount of processing gas and/or different processing gas mixture, especially with a variation of reactive gases, independently for the first outer deposition assembly 301 the second outer deposition assembly 302 and the inner deposition assembly 303.

[0033] FIG. 3A shows a schematic cross-sectional view of a deposition apparatus 100 according to embodiments as described herein. Exemplarily, one vacuum chamber 102 for deposition of layers therein is shown. As indicated in FIG. 3 A, further chambers 103 can be provided adjacent to the chamber 102. The vacuum chamber 102 can be separated from adjacent chambers by a valve having a valve housing 104 and a valve unit 105. After the carrier 114 with the substrate 14 thereon is, as indicated by arrow 1, inserted in the vacuum chamber 102, the valve unit 105 can be closed. Accordingly, the atmosphere in the vacuum chambers 102 and 103 can be individually controlled by generating a technical vacuum, for example, with vacuum pumps connected to the chamber 102 and 103, and/or by inserting processing gases in the deposition region in the chamber 102. As described above, for many large area processing applications, the large area substrates are supported by a carrier. However, embodiments described herein are not limited thereto and other transportation elements for transporting a substrate through a processing apparatus or processing system may be used.

[0034] Within the chamber 102, a transport system is provided in order to transport the carrier 114, having the substrate 14 thereon, into and out of the chamber 102. The term "substrate" as used herein shall embrace inflexible substrates, e.g., a glass substrate, a wafer, slices of transparent crystal such as sapphire or the like, or a glass plate.

[0035] As illustrated in FIG. 3A, within the chamber 102, deposition sources 122 are provided. The deposition sources can for example be rotatable cathodes having targets of the material to be deposited on the substrate. According to embodiments which can be combined with other embodiments described herein, the cathodes can be rotatable cathodes with a magnet assembly 121 therein. Magnetron sputtering can be conducted for depositing of the layers. As exemplarily shown in FIG. 3A each pair of neighboring cathodes can be connected to a power supply 123. Depending on the nature of the deposition process within the target array either each pair of neighboring cathodes can be connected to an AC power supply or each cathode can be connected to a DC power supply. According to some embodiments, which can be combined with other embodiments described herein, the cathodes 122 are connected to an AC power supply such that the cathodes can be biased in an alternating manner. AC power supplies 123 such as MF power supplies can for example be provided for depositing layers of A1203. In such a case, the cathodes do not require additional anodes, which can e.g. be removed, as a complete circuit including cathode and anode is provided by a pair of cathodes 122.

[0036] With exemplary reference to FIG. 3B, according to other embodiments, the apparatus may include cathodes 122 and anodes 115, which may be electrically connected to a DC power supply. According to further embodiments, which can be combined with other embodiments described herein, the deposition apparatus can comprise one anode extending along the horizontal direction or at least three anodes, as exemplarily shown in FIG. 3B, which are spaced apart along the horizontal direction.

[0037] Sputtering from a target for e.g. a transparent conductive oxide film is typically conducted as DC sputtering. The cathodes may be connected to the DC power supply together with the anode for collecting electrons during sputtering. According to some embodiments, which can be combined with other embodiments described herein, the gas lines 116 can be provided on one side of the anode 115 or a shield and the cathode can be provided on the other side of the anode or shield (see e.g. FIG. 3A). The gas can be provided in the deposition area through openings (not shown) in the anode or shield. According to an alternative implementation, the gas lines or conduits and the cathodes may also be provided in the same side of the anode or shield.

[0038] According to yet further embodiments, which can be combined with other embodiments described herein, one or more of the cathodes can each have their corresponding, individual voltage supply. For example, one power supply can be provided per cathode for at least one, some or all of the cathodes. Accordingly, at least a first cathode can be connected to a first power supply, and a second cathode can be connected to a second power supply. According to yet further embodiments, which can be combined with other embodiments described herein, for example, materials like ΓΓΟ, IZO, IGZO or MoN, might be deposited with a DC sputter deposition process.

[0039] As further illustrated in FIG. 3B, within the chamber 102, multiple gas lines 116 and mask shields 130 are also provided. As exemplarily shown in FIG. 3A and 3B, the gas distribution system of apparatus 100 may include six gas tanks 136 containing processing gas. The flow rate of non-reactive gas and/or reactive gas present in the processing gas can be controlled by MFCs 135. The processing gas may be fed to multiple gas inlet points 138 (not shown) within multiple gas lines 126 through gas conduits or gas pipes 133, 233 and 333 via MFCs 134, 234 and 334, respectively. Accordingly, the embodiments of the apparatus as described herein allow for providing a different flow rate of processing gas and/or different processing gas mixture independently to the first outer deposition assembly 301, the second outer deposition assembly 302 and the inner deposition assembly 303. Accordingly, an apparatus for depositing material on a substrate is provided with which a thickness drop at the substrate edges in transport direction can substantially be avoided.

[0040] As shown in FIGS. 3 A and 3B, embodiments described herein can be provided for a static deposition process, e.g. valve units 105 are closed during deposition, with a plurality of rotary cathodes, e.g. three or more rotary cathodes. While deposition process is switched off, the substrate 14 is moved into the position for deposition in the deposition area. The process pressure can be stabilized. Once the process is stabilized, the cathode magnet assemblies 121 can be rotated toward the front to deposit the correct stoichiometry of the material to be deposited onto the static substrate until end of deposition. [0041] With exemplary reference to FIGS. 3A and 3B, the apparatus according to embodiments as described herein, may include a controller 500 which is configured for controlling at least one process parameter of the first outer deposition assembly and the second outer deposition assembly. Further, the controller 500 may be configured for controlling at least one process parameter of the inner deposition assembly. According to embodiments as described herein, a deposition assembly (e.g. the first outer deposition assembly, the second outer deposition assembly and the inner deposition assembly) may include at least one cathode, particularly a rotary cathode, a gas distribution system or a segment of a gas distribution system, and a magnetic assembly. Therefore, according to embodiments as described herein the at least one processing parameter can be controlled by the controller 500. According to embodiments described herein, the at least one processing parameter is at least one selected from the group consisting of: a power supplied to the first outer deposition assembly and the second outer deposition assembly, an amount of processing gas supplied to the first outer deposition assembly and the second outer deposition assembly, and a magnetic field at the first outer deposition assembly and the second outer deposition assembly. Accordingly, an apparatus for deposition of material on a substrate is provided with which is configured such that material can be deposited at the first outer deposition assembly 301 and/or the second outer deposition assembly (302) at a higher rate than at the inner deposition assembly 303 on the same substrate during the same time. Accordingly, an apparatus for depositing material on a substrate is provided with which a thickness drop at the substrate edges in transport direction can substantially be avoided.

[0042] According to embodiments which can be combined with other embodiments described herein, the controller 500 is configured for controlling a first power supply for supplying a first power to the first outer deposition assembly and the second outer deposition assembly. The controller can also be configured for controlling a second power supply for supplying a second power to the inner deposition assembly. With reference to the exemplary embodiments of FIGS. 3 A and 3B, the first power supply for supplying a first power to the first outer deposition assembly and the second outer deposition assembly can include two separate power supplies 123a, 123c for supplying the first power to the first outer deposition assembly and the second outer deposition assembly. [0043] As illustrated in FIGS. 3A and 3B, within the chamber 102, deposition sources 122 are provided. The deposition sources can for example be rotatable cathodes having targets of the material to be deposited on the substrate. Typically, the cathodes can be rotatable cathodes with a magnet assembly 121 therein. Accordingly, magnetron sputtering can be conducted for depositing of material on a substrate. As exemplarily shown in FIGS. 3A and 3B, the deposition process can be conducted with rotary cathodes and a rotating magnet assembly, i.e. a rotating magnet yoke therein.

[0044] As used herein, "magnetron sputtering" refers to sputtering performed using a magnetron, i.e. a magnet assembly, that is, a unit capable of generating a magnetic field. Typically, such a magnet assembly consists of one or more permanent magnets. These permanent magnets are typically arranged within a rotatable target or coupled to a planar target in a manner such that the free electrons are trapped within the generated magnetic field generated below the rotatable target surface. Such a magnet assembly may also be arranged coupled to a planar cathode. According to typical implementations, magnetron sputtering can be realized by a double magnetron cathode, i.e. cathodes 122, such as, but not limited to, a TwinMagTM cathode assembly. Particularly, for MF sputtering (middle frequency sputtering) from a target, target assemblies including double cathodes can be applied. According to typical embodiments, the cathodes in a deposition chamber may be interchangeable. Accordingly, the targets are changed after the material to be sputtered has been consumed. [0045] According to different embodiments, which can be combined with other embodiments described herein, sputtering can be conducted as DC sputtering, MF (middle frequency) sputtering, as RF sputtering, or as pulse sputtering. As described herein, some deposition processes might beneficially apply MF, DC or pulsed sputtering. However, other sputtering methods can also be applied. [0046] In FIGS. 3A and 3B a plurality of cathodes 122 with a magnet assembly 121 or magnetron provided in the cathodes are shown. According to some embodiments, which can be combined with other embodiments described herein, the sputtering according to the described embodiments can be conducted with three or more cathodes. However, particularly for applications for large area deposition, an array of cathodes or cathode pairs can be provided. For example, three or more cathodes or cathode pairs, e.g. three, four, five, six or even more cathodes or cathode pairs can be provided. The array can be provided in one vacuum chamber. Further, an array can typically be defined such that adjacent cathodes or cathode pairs influence each other, e.g. by having interacting plasma confinement.

[0047] For rotatable cathodes, the magnet assemblies can be provided within a backing tube or with the target material tube. FIG. 3A shows 3 pairs of cathodes, each providing a deposition source. The pair of cathodes may have an AC power supply, e.g. for MF sputtering, RF sputtering or the like. Particularly for large area deposition processes and for deposition processes on an industrial scale, MF sputtering can be conducted in order to provide desired deposition rates. According to embodiments, as exemplarily shown in FIGS. 3A and 3B, the magnet assemblies of the cathodes in the vacuum chamber 102 can have essentially the same rotational positions or can at least all be directed towards the substrate 14 or a corresponding deposition area. Typically, the deposition area is an area or region with a deposition system, which is provided and/or arranged for the depositing (the intended deposition) of the material on a substrate.

[0048] Yet, according to different embodiments, which can be combined with other embodiments described herein, the plasma sources in one chamber can have varying plasma positions (rotational positions for rotary cathodes) during the deposition of the layer on the substrate. For example, the magnet assemblies or magnetrons can be moved relative to each other and/or relative to the substrate, e.g. in an oscillating or back-and- forth manner, in order to increase the uniformity of the layer to be deposited. For example, the magnet assemblies of the first outer deposition assembly and the second outer deposition assembly may be moved differently compared to the magnet assemblies of the inner deposition assembly for realizing a higher deposition rate of material of the first outer deposition assembly and the second outer deposition assembly compared to the inner deposition assembly.

[0049] According to embodiments which can be combined with other embodiments described herein the first outer deposition assembly 301 includes a first magnet assembly for generating a first magnetic field and the second outer deposition assembly 302 includes a second magnet assembly for generating the first magnetic field, and the inner deposition assembly includes a second magnet assembly for generating a second magnetic field. The first magnetic field can be different from the second magnetic field due to at least one means selected from the group consisting of: selection of magnetic material, selection of geometry of the magnetic assembly, a controllable electromagnet, an element for controlling the first magnetic field and/or the second magnetic field. The element for controlling the first magnetic field and/or the second magnetic field can for example be an eccentric arrangement 410 configured for varying the position of the magnetic assembly 121 in relation to the cathodes, as exemplarily shown in FIGS. 4A and 4B. According to embodiments described herein the magnetic field at the outer deposition assemblies 301 and 302, as exemplarily shown in FIGS. 3A and 3B, may be controlled and adjusted for realizing higher deposition rates at the outer deposition assemblies 301 and 302 such that thickness drops at the edges of a layer deposited on a substrate can substantially be avoided. [0050] In FIG 4A a schematic cross-sectional view of a rotary cathode 122 according to embodiments described herein is shown, wherein the eccentric arrangement 410 is in a position in which the distance D between the magnetic assembly 121 and the cathode 122 is minimized. FIG 4B shows a schematic cross-sectional view of a rotary cathode 122 according to embodiments described herein is shown, wherein the eccentric arrangement 410 is in a position in which the distance D between the magnetic assembly 121 and the cathode 122 is maximized.

[0051] According to some embodiments, which can be combined with other embodiments described herein, the embodiments described herein can be utilized for Display PVD, i.e. sputter deposition on large area substrates for the display market. According to some embodiments, large area substrates or respective carriers, wherein the carriers have a plurality of substrates, may have a size of at least 0.67 m ² . Typically, the size can be about 0.67m2 (0.73x0.92m - Gen 4.5) to about 8 m ² , more typically about 2 m ² to about 9 m ² or even up to 12 m ² . Typically, the substrates or carriers, for which the structures, apparatuses, such as cathode assemblies, and methods according to embodiments described herein are provided, are large area substrates as described herein. For instance, a large area substrate or carrier can be GEN 4.5, which corresponds to about 0.67 m ² substrates (0.73x0.92m), GEN 5, which corresponds to about 1.4 m ² substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m ² substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7m ² substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m ² substrates (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can similarly be implemented.

[0052] According to yet further embodiments, which can be combined with other embodiments described herein, the target material can be selected from the group consisting of: aluminum, silicon, tantalum, molybdenum, niobium, titanium, indium, gallium, zinc, tin, silver and copper. Particularly, the target material can be selected from the group consisting of indium, gallium and zinc. The reactive sputter processes provide typically deposited oxides of these target materials. However, nitrides or oxi-nitrides might be deposited as well.

[0053] According to embodiments described herein, the methods provide a sputter deposition for a positioning of the substrate for a static deposition process. Typically, particularly for large area substrate processing, such as processing of vertically oriented large area substrates, it can be distinguished between static deposition and dynamic deposition. According to some embodiments, which can be combined with other embodiments described herein, the substrates and/or the carriers described herein and the apparatuses for utilizing the gas distribution systems described herein, can be configured for vertical substrate processing. The term vertical substrate processing is understood to distinguish over horizontal substrate processing. That is, vertical substrate processing relates to an essentially vertical orientation of the carrier and the substrate during substrate processing, wherein a deviation of a few degrees, e.g. up to 10° or even up to 15°, from an exact vertical orientation is still considered as vertical substrate processing. A vertical substrate orientation with a small inclination can for example result in a more stable substrate handling or reduced risk of particles contaminating a deposited layer. Alternatively, the gas distribution systems according to embodiments described herein may also be utilized for substrate orientations other than essentially vertical, e.g. a horizontal substrate orientation. For a horizontal substrate orientation the cathode array would for example also be essentially horizontal.

[0054] A dynamic sputtering, i.e. an inline process where the substrate moves continuously or quasi-continuously adjacent to the deposition source, would be easier due to the fact the process can be stabilized prior to the substrates moving into a deposition area, and then held constant as substrates pass by the deposition source. Yet, a dynamic deposition can have other disadvantages, e.g. particle generation. This might particularly apply for TFT backplane deposition. According to embodiments described herein a static sputtering can be provided, e.g. for TFT processing, wherein the plasma can be stabilized prior to deposition on the pristine substrate. It should be noted that the term static deposition process, which is different as compared to dynamic deposition processes, does not exclude any movement of the substrate as would be appreciated by a skilled person. A static deposition process can include, for example, a static substrate position during deposition, an oscillating substrate position during deposition, an average substrate position that is essentially constant during deposition, a dithering substrate position during deposition, a wobbling substrate position during deposition, a deposition process for which the cathodes provided in one chamber, i.e. a predetermined set of cathodes provided in the chamber, a substrate position wherein the deposition chamber has a sealed atmosphere with respect to neighboring chambers, e.g. by closing valve units separating the chamber from an adjacent chamber, during deposition of the layer, or a combination thereof.

[0055] Accordingly, a static deposition process can be understood as a deposition process with a static position, a deposition process with an essentially static position, or a deposition process with a partially static position of the substrate. A static deposition process, as described herein, can be clearly distinguished from a dynamic deposition process without the necessity that the substrate position for the static deposition process is fully without any movement during deposition. According to yet further embodiments, which can be combined with other embodiments described herein, a deviation from an fully static substrate position, e.g. oscillating, wobbling or otherwise moving substrates as described above, which is still considered a static deposition by a person skilled in the art, can additionally or alternatively be provided by a movement of the cathodes or the cathode array, e.g. wobbling, oscillating or the like. The substrate and the cathodes (or the cathode array) can move relative to each other, e.g. in substrate transport direction, in a lateral direction essentially perpendicular to the substrate transport direction or both.

[0056] According to embodiments described herein which can be combined with other embodiments described herein, the apparatus 100, as exemplarily shown in FIG. 5, including a deposition array having three or more cathodes, a first outer deposition assembly defines a first edge section 501 in a substrate transport direction and a second outer deposition assembly defines a second edge section 502 opposing the first edge section in substrate transport direction. Further, the deposition array includes a third edge section 503 including first ends of the at least one inner cathode of the inner deposition assembly and a forth edge section 504 including opposing second ends of the cathodes of the remaining section 505 of the cathode array. The extension of the third edge section 503 and/ or the fourth edge section in direction of the axis of the cathodes may correspond to at least 5% of the total cathode length, particularly to at least 10% of the total cathode length, particularly to at least 15% of the total cathode length, respectively. Accrodingly, an apparatus for depositing material on a substrate is provided with which thickness drops at the edges of the substrate in transport direction as well as at the substrate edges perpendicular to the substrate transport direction can substantially be avoided.

[0057] As shown in FIG. 5, further embodiments of the apparatus described herein provide a processing gas distribution system having segments located at the first edge section 501, at the second edge section 502, at the third edge section 503, at the fourth edge section 504 and at the remaining section 505 of the deposition array 222. As exemplarily shown in FIG. 5, multiple gas inlet points 138 within multiple gas lines 116 may be provided. For example, each gas line can have three or more openings, such as six or more openings, e.g. 6 to 20 openings. The multiple gas lines 116 can be placed between pairs of cathodes 122, e.g. parallel to their longitudinal axes along the horizontal direction. As exemplarily shown in FIG. 5, the processing gas can be supplied by five MFCs 134, one MFC for each section. Accrodingly, the amount of processing gas supplied to each individual section may be controlled independently. Accordingly, the partial pressure of the processing gas provided to the individual sections may be adjusted independently.

[0058] Although not explicitly shown in FIG. 5, each of the five MFCs 134 may be connected to two tanks containing processing gas, similar as described in connection with the embodiments as shown in FIGS. 2, 3 A and 3B. Accordingly, the flow rate and/or amount of non-reactive gas and/ or reactive gas present in the processing gas in the individual sections 501, 502, 503, 504 and 505 can be controlled by MFCs 135, as exemplarily described in connection with the embodiment shown in FIG. 2. Alternatively, the MFCs 134 connected to the first edge section 501, the second edge section 502, the third edge section 503, and the fourth edge section 504 can be connected to one single gas tank or one single gas tank battery including two tanks for each of the processing gases. The MFC 134 connected to the remaining section located between the first edge section, the second edge section, the third edge section and the forth edge section may be connected to another single gas tank or another single gas tank battery including two tanks for each of the processing gases.

[0059] According to embodiments an apparatus for deposition of material on a substrate having a gas distribution system is provided which is configured for providing a first processing gas condition to the first edge section, the second edge section, the third edge section and the forth edge section for depositing the material at a higher rate than in the remaining section located between the first edge section, the second edge section, the third edge section and the forth edge section. Hence, according to embodiments described herein an apparatus is provided for providing a uniform coating on the complete substrate, i.e. including the substrate edges in transport direction of the substrate as well as the substrate edges perpendicular to the substrate transport direction. [0060] Embodiments corresponding to FIGS. 2, 3 A and 3B show gas distribution systems with one gas line per two targets. However, gas distribution systems according to embodiments described herein can have any number of gas lines. For example, gas distribution systems can have four gas lines to thirteen gas lines. Similarly, each gas line can have two to thirty gas inlet points. For example, each gas line can have three to twenty gas inlet points, such as five to ten, e.g. nine, gas inlet points. [0061] Accordingly, embodiments described herein allow controlling and adjusting the processing gas composition at the outer deposition assemblies in transport direction. Further, embodiments described herein allow controlling and adjusting the processing gas condition at the edge sections of the cathode array as described herein, in particular with reference to the embodiment as shown in FIG. 5. Embodiments described herein provide precise control for depositing layers having substantially constant thickness over the complete substrate including its edges.

[0062] According to typical embodiments, the cathode array may comprise three or more rotary sputter targets, particularly the cathode array may comprise eight rotary sputter targets, more particularly the cathode array may comprise twelve rotary sputter targets. Typically, the cathodes of the cathode array are spaced from one another such that their longitudinal axes are parallel to each other and wherein the longitudinal axes are arranged equidistant from the substrate to be treated.

[0063] An embodiment of a method 600 for deposition of material on a substrate is shown in FIG. 6. In step 601 a deposition array having three or more cathodes is provided, wherein the deposition array includes a first outer deposition assembly 301 comprising at least a first cathode of the three or more cathodes, a second outer deposition assembly 302 opposing the first outer deposition assembly 301 including at least a second cathode of the three or more cathodes, and an inner deposition assembly 303 including at least one inner cathode located between the first outer deposition assembly 301 and the second outer deposition assembly 302. In step 602 material on the substrate with the at least one of the first outer deposition assembly 301 and the second outer deposition assembly 302 is deposited at a higher rate than with the inner deposition assembly. Accordingly, a method for deposition of material on a substrate is provided with a thickness drop at the substrate edges in transport direction can substantially be avoided. Particularly, the method as described herein allows for deposition of uniform coatings on substrates, particularly on large area substrates during static deposition processes.

[0064] According to embodiments of the method as described herein, depositing material on the substrate with the at least one of the first outer deposition assembly and the second outer deposition assembly includes controlling at least one processing parameter selected from the group consisting of: controlling a power supplied to the first outer deposition assembly and/or the second outer deposition assembly, controlling an amount of processing gas supplied to the first outer deposition assembly and/or the second outer deposition assembly, controlling a first magnetic field at the first outer deposition assembly and/or the second outer deposition assembly, and controlling a second magnetic field at inner deposition assembly. Accordingly, a method for depositing material on a substrate is provided with which material can be deposited at the first outer deposition assembly 301 and/or the second outer deposition assembly (302) at a higher rate than at the inner deposition assembly 303 on the same substrate during the same time. Accordingly, the method as described provides for depositing material on a substrate such that a thickness drop at the substrate edges in transport direction can substantially be avoided.

[0065] According to embodiments which can be combined with other embodiments described herein, controlling the first magnetic field and/ or the second magnetic field may include at least one selected from the group consisting of: selecting an magnetic material, selecting an geometry of an magnetic arrangement, controlling an electromagnet, and using an element for controlling the first magnetic field and/or the second magnetic field. For example, the element for controlling the first magnetic field and/or the second magnetic field can be an eccentric arrangement configured for varying the position of the magnetic assembly in relation to the cathodes as exemplarily described in connection with FIG. 4A and FIG. 4B above. [0066] According to further embodiments of the method for deposition of material on a substrate as described herein, step 601 may include providing a deposition array in which the first outer deposition assembly defines a first edge section in a substrate transport direction and the second outer deposition assembly defines a second edge section opposing the first edge section in substrate transport direction, wherein the deposition array further includes a third edge section including first ends of the at least one inner cathode of the inner deposition assembly and a forth edge section including opposing second ends of the cathodes of the remaining section of the cathode array. Accordingly, step 602 may include depositing material on the substrate at the first edge section, the second edge section, the third edge section and the forth edge section at a higher rate than in the remaining section located between the first edge section, the second edge section, the third edge section and the forth edge section. Hence, according to embodiments described herein a method is provided for providing a uniform coating on the complete substrate, i.e. including the substrate edges in transport direction of the substrate as well as the substrate edges perpendicular to the substrate transport direction.

[0067] According to embodiments described herein, the material is deposited on the substrate, wherein the substrate is positioned for a static deposition process. Typically, the material of the target can be deposited in the form of an oxide, a nitride, or an oxi-nitride of the target material, i.e. with a reactive sputtering process.

[0068] While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.