CONFIGURED FOR DEPOSITING MATERIAL ON A SUBSTRATE WITH FACING SPUTTER TARGETS

TECHNICAL FIELD

[0001 ] Embodiments of the present disclosure relate to a deposition of material on a substrate.

Particularly, embodiments relate to low damage deposition of material, wherein magnetron sputtering is provided with a magnetron position resulting in facing plasma confinement regions. Embodiments of the present disclosure further relate to deposition of material on a substrate by sputtering from rotary targets. Specifically, embodiments relate to methods of depositing material on a substrate and systems configured for depositing material on a substrate, for example, with facing sputter targets.

BACKGROUND

[0002] Deposition of material on a substrate has many applications in various technical fields. Sputtering is a method for deposition of a material on a substrate. Sputtering can be associated with a bombardment of the substrate, particularly a film located on the substrate, with energetic particles. The bombardment may have a disadvantageous influence on the properties of a material, particularly a film, located on the substrate. To avoid the bombardment, facing target sputtering (FTS) systems were devised, for example, with planar targets. In an FTS system, instead of facing the substrate directly, the targets face each other. However, the stability of the sputtering plasma in conventional FTS systems is limited. The suitability of conventional FTS systems for use in mass production is impaired. Advanced FTS systems can include rotary targets to increase material utilization.

[0003] In view of the above, it is beneficial to provide improved methods and systems for depositing material on a substrate. SUMMARY

[0004] In light of the above, a method of depositing material on a substrate according to claim 1 and a system configured for depositing material on a substrate with facing sputter targets are provided. Further features, aspects, details, and implementations are described in the detailed specification, the drawings, and the dependent claims.

[0005] According to an embodiment, a method of depositing a material on a substrate is provided. The method includes sputtering from a first rotary target having a first magnet assembly having a first plasma confinement and with an aperture plate and sputtering simultaneously from a second rotary target having a second magnet assembly having a second plasma confinement and with the aperture plate. The first plasma confinement faces the second rotary target and the second plasma confinement faces the first rotary target. The first plasma confinement and the second plasma confinement providing a plasma region between the first rotary target and the second rotary target have a center line perpendicular to a substrate surface of the substrate, the aperture plate having a body with a shielding portion configured to shield a region between the plasma region and the substrate at least at the center line.

[0006] According to an embodiment, a system configured for depositing material on a substrate with facing sputter targets is provided. The system includes a first target support for a first rotary target having a first target position; a second target support for a second rotary target at a second target position; and an aperture plate having one or more apertures and a shielding portion at a center line perpendicular to a substrate surface of the substrate between the first target position and the second target position.

[0007] The present disclosure is to be understood as encompassing apparatuses and systems for carrying out the disclosed methods, including apparatus parts for performing each described method aspect. Method aspects may be performed for example by hardware components, by a computer programmed by appropriate software or by any combination of the two. The present disclosure is also to be understood as encompassing methods for operating described apparatuses and systems. Methods for operating the described apparatuses and systems include method aspects for carrying out every function of the respective apparatus or system. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] So that the features recited above can be understood in detail, a more particular description of the subj ect matter briefly summarized above may be provided below by reference to embodiments. The accompanying drawings relate to embodiments and are described in the following:

[0009] FIG. 1 is a schematic sectional view of a system for depositing a material, according to embodiments described herein and for explaining methods of material deposition according to embodiments of the present disclosure;

[0010] FIG. 2 is a schematic sectional view illustrating the effect of an aperture plate as shown in FIG. 1;

[0011] FIG. 3 is a schematic sectional view of a system for depositing a material, according to embodiments described herein and for explaining methods of material deposition according to embodiments of the present disclosure;

[0012] FIGS. 4A and 4B are schematic views of material layers deposited on a substrate according to different embodiments of the present disclosure, for example, according to FIG. 1 and according to FIG. 3;

[0013] FIGS. 5 A and 5B are schematic sectional views of a system for depositing material according to embodiments of the present disclosure and for explaining methods of material deposition according to embodiments of the present disclosure;

[0014] FIGS. 6 A and 6B are schematic sectional views of a system for depositing material according to embodiments of the present disclosure and for explaining methods of material deposition according to embodiments of the present disclosure; and

[0015] FIG. 7 is a chart illustrating a method of depositing a material on a substrate, according to embodiments described herein. DETAILED DESCRIPTION OF EMBODIMENTS

[0016] Reference will now be made in detail to the various embodiments, wherein one or more examples of the embodiments are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. Generally, only the differences with respect to individual embodiments are described. Each example is provided as an explanation and is not meant as a limitation. 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.

[0017] Facing target sputtering (FTS) systems provide plasma confinement regions facing each other, i.e. pointing directly or at least partially towards the other, opposing target. Since the plasma confinement of one or more targets is not directed towards the substrate but parallel or essentially parallel with a deviation of some degrees, e.g. up to 30°, away from the substrate or towards the substrate, damage that may occur at the substrate due to the energy of the particles being deposited on the substrate or UV radiation is reduced. Low damage deposition (LDD) can be provided. However, the sputtering rate is lower as compared to magnetron sputtering having a plasma confinement directed towards the substrate, for example at an angle of 90°. Accordingly, it is beneficial to improve the sputter rate at a given damage level and/or to further reduce the damage at a given sputter rate.

[0018] According to embodiments of the present disclosure, off-centric LDD is provided to improve the damage-to-depositi on-rate ratio of facing target sputtering. Off-centric LDD blocks the shortest sputter paths between the plasma confinement region and the substrate by an aperture plate having centric positioned shielding portion(s). An off-centric aperture can be provided with respect to the facing targets. An aperture is provided, for example, exclusively provided, for longer sputter paths to reduce the kinetic particle energy and/or to block the most intense UV radiation which is emitted out of the center of the facing target, particularly on a short mean free path.

[0019] According to an embodiment, a method of depositing a material on a substrate is provided. The method includes a first deposition with sputtering from a first rotary target having a first magnet assembly having a first plasma confinement and with an aperture plate and sputtering simultaneously from a second rotary target having a second magnet assembly having a second plasma confinement and with the aperture plate. The first plasma confinement faces the second rotary target and the second plasma confinement faces the first rotary target. The first plasma confinement and the second plasma confinement providing a plasma region between the first rotary target and the second rotary target have a center line perpendicular to a substrate surface of the substrate, the aperture plate having a body with a shielding portion configured to shield a region between the plasma region and the substrate at least at the center line. Embodiments described herein, which relate to methods of depositing material on a substrate, can be similarly applied to methods of manufacturing a device, particularly for transparent electrodes in displays, such as OLED displays, liquid crystal displays, and touchscreens.

[0020] According to an embodiment, a system configured for depositing material on a substrate with facing sputter targets is provided. The system includes a first target support for a first rotary target having a first target position and a second target support for a second rotary target at a second target position. An aperture plate is provided. The aperture plate has at least one aperture and a shielding portion at a center line perpendicular to a substrate surface of the substrate between the first target position and the second target position.

[0021] The already reduced sputter damage of FTS as compared to non-FTS sputtering, on sensitive layers and/or sensitive substrates can be further reduced by the shielding portion, e.g. the centric shield portion, and the off-centric aperture. The damage vs. sputter rate ratio is improved in addition to other process adjustments, such as increasing process pressure or increasing the distance between target center and substrate.

[0022] FIG. 1 is a schematic sectional view of a system for depositing at least one material, according to embodiments described herein. The system 100 is for depositing the at least one material on a substrate 102. The substrate 102 may be provided on a substrate holder 104. The system 100 includes a first target support for a first rotary target 110 and a second target support for a second rotary target 120. The first and the second rotary target can each be mounted to the respective target support. In embodiments, the system includes the first and the second rotary target. An aperture plate 140 is provided. The aperture plate has one or more apertures (one aperture is shown in FIG. 1) and includes a shielding portion 150. The shielding portion 150 is provided at least at a center line 134, the center line being perpendicular to the surface of the substrate 102. The center line 134 corresponds to a center of the plasma region between the first rotary target 110 and the second rotary target 120. The shielding portion blocks material particles from the first rotary target and/or the second rotary target moving towards the substrate 102.

[0023] The system 100 includes a first magnet assembly 112 connectable to the first target support. In particular, when the first magnet assembly 112 is connected and a first rotary target 110 is mounted to the first target support, the first magnet assembly 112 is positioned within the first rotary target 110. The system further includes a second magnet assembly 122 connectable to the second target support. In particular, when the second magnet assembly 122 is connected and a second rotary target 120 is mounted to the second target support, the second magnet assembly 122 is positioned within the second rotary target 120.

[0024] Generally, a target support for a rotary target may include or consist of at least one end block. An end block may include a target mounting flange configured to support a rotary target while allowing rotation relative to the end block. The end block may include at least one utility shaft configured to support at least one magnet assembly. The end block may include a fitting for delivery of a cooling fluid to the rotary target.

[0025] Plasma associated with the sputter deposition may be trapped between the first and the second rotary target. The plasma confinement of the first magnet assembly and the plasma confinement of the second magnet assembly may overlap at least partially. In particular, the first and the second rotary target are neighboring targets. More particularly, there are no further targets positioned in a region between the first and the second rotary target.

[0026] In the context of the present disclosure, a plasma confinement is particularly to be understood as a plasma confinement region. A plasma confinement region may be understood as a region where the amount of plasma is increased relative to the environment, particularly due to the effect of a magnetic field of a magnet assembly located in a rotary target. In the context of the present disclosure, providing a plasma confinement in a specific direction is particularly to be understood as providing the plasma confinement such that a main direction of the plasma confinement extends in the specific direction. [0027] Particularly in embodiments where the magnet assembly includes a permanent magnet, providing a plasma confinement in a specific direction may be understood as providing the magnet assembly at a position such that the magnet assembly faces the specific direction. In particular, a symmetry axis of the magnet assembly faces the specific direction. For example, providing a plasma confinement in a direction facing a rotary target, e.g. a neighboring rotary target, may be understood as the magnet assembly facing the rotary target.

[0028] According to some embodiments of the present disclosure, a plasma confinement is provided in a plasma racetrack, particularly a closed plasma racetrack. The plasma confinement associated with one magnet assembly provides a closed loop. The closed loop may for example be provided at one target, i.e. the target in which the magnet assembly is provided.

[0029] A magnet assembly positioned within a rotary target may enable magnetron sputtering. As used herein, “magnetron sputtering” refers to sputtering performed using a magnetron, i.e. a rotary target having a magnet assembly positioned within. A magnet assembly is particularly to be understood as a unit capable of generating a magnetic field. A magnet assembly may include one or more permanent magnets. The permanent magnets may be arranged within a rotary target such that free electrons are trapped within the generated magnetic field, e.g. in a closed loop or a racetrack. The magnet assembly can be provided within a backing tube of the rotary target or within the target material tube. Rotary targets described herein may be a cathode or a portion of a cathode. The system may be configured for DC sputtering. In embodiments, the system may be configured for pulsed DC sputtering.

[0030] In rotary targets, the removal of material from the target during magnetron sputtering has an improved uniformity, when compared to magnetron sputtering from planar targets. The uniformity in the case of rotary targets is particularly caused by the movement of the target surface relative to the magnetic field due to the rotation of the targets. The amount of material collected on a target surface may be reduced or even eliminated. Stability, particularly longterm stability of the deposition process may be increased. Use of the facing target sputtering concept for mass production may be enabled, in light of the reduced material collected and the stability of the process.

[0031] In embodiments, the first magnet assembly 112 includes at least three magnetic poles facing a plasma confinement 114 provided by the first magnet assembly. The second magnet assembly 122 may include at least three magnetic poles facing a plasma confinement 124 provided by the second magnet assembly 122. The rotary targets 110, 120 are positioned in a deposition chamber 152. In particular, the deposition chamber 152 can be a vacuum chamber. A first additional chamber and a second additional chamber may be provided adjacent to the deposition chamber (not shown).

[0032] According to some embodiments, which can be combined with other embodiments described herein, depositing a material on the substrate can be provided with a dynamic deposition process. For example, the substrate can move past the first rotary target and the second rotary target while material is deposited. This is indicated by arrow 105. Accordingly, an in-line deposition process can be provided.

[0033] According to some embodiments, which can be combined with other embodiments described herein, depositing a material on the substrate can be provided as a static deposition process. The static deposition process deposits material in a batch process. A substrate is moved into the deposition chamber. The substrate can be moved back and forth as indicated by arrow 107 past the aperture plate 140. The deposition chamber or regions of a vacuum processing system may be separated from further chambers or other regions by a valve. After deposition of a substrate in the deposition chamber, the substrate 102 can be moved out of the deposition chamber and a further substrate can be moved into the deposition chamber.

[0034] According to some embodiments, process gases can include at least one of a noble gas or a reactive gas. For example, a noble gas can be argon, krypton, xenon, or combinations thereof. For example, a reactive gas can be oxygen, nitrogen, hydrogen, ammonia (NH3), nitrous oxide (N2O), ozone (03), carbon oxide (CO2) an activated gas, or combinations thereof.

In embodiments, the at least one material includes or is a metal, a metal oxide (MOx), or a transparent conductive oxide (TCO). The metal may be for example Ag, MgAg, Al, Yb, Ca, or Li. The metal oxide may be for example IGZO, A1O, MoO, or WOx. The TCO may be for example indium zinc oxide (IZO), indium tin oxide (ITO), or aluminum -doped zinc oxide (AZO). In some embodiments, which can be combined with embodiments described herein, the sputter deposition source may be configured for sputtering of a transparent conductive oxide film. In some embodiments, which can be combined with embodiments described herein, a system or a method may be configured for deposition of materials like indium tin oxide (ITO), indium zinc oxide (IZO), aluminum doped (AZO), indium gallium zinc oxide (IGZO), indium gallium zinc tin oxide (IGZTO); or MoN. In some embodiments, which can be combined with embodiments described herein, a system or a method may be configured for deposition of metallic material like silver, magnesium silver (MgAg), aluminum, indium, indium tin (InSn), indium zinc (InZn), gallium, gallium zinc (GaZn), niobium, alkali metals (like Li or Na), alkaline earth metals (like Mg or Ca), yttrium (Y), ytterbium (Yb), lanthanum (La), lanthanides (like Ce, Nd, or Dy) and alloys of those materials. In some embodiments, which can be combined with embodiments described herein, a system or a method may be configured for deposition of metal oxide materials such as A1O _X , NbO _x , SiO _x , WO _X , ZrO _x . The sputter deposition source may be configured for the deposition of electrodes, particularly transparent electrodes in displays, particularly OLED displays, liquid crystal displays, and touchscreens. More particularly, the system may be configured for deposition of top contacts for top-emitting OLEDs. In some embodiments, which can be combined with embodiments described herein, a system or a method may be configured for deposition of electrodes, particularly transparent electrodes in thin film solar cells, photodiodes, and smart or switchable glass. The system may be configured for sputtering transparent dielectrics used as charge generation layers. The system may be configured for deposition of materials like molybdenum oxide (MoO), or transition metal oxides like vanadium oxide (VO) or tungsten oxide (WOx), zirconium oxide (ZrO) or lanthanum oxide (LaO). The system may be configured for sputtering transparent dielectrics used for optical enhancement layers like silicon oxide (SiO), niobium oxide (NbO), titanium oxide (TiO), or tantalum oxide (TaO).

[0035] The term “substrate” as used herein shall embrace both inflexible substrates and flexible substrates. Examples of inflexible substrates include glass substrates, glass plates, wafers, or slices of a transparent crystal such as sapphire or the like. Examples of flexible substrates include webs or foils. According to yet further embodiments, which can be combined with other embodiments described herein, transportation of the substrate and/or the substrate carrier can respectively be provided by a magnetic levitation system. A carrier can be levitated or can be held without mechanical contact or with reduced mechanical contact by magnetic forces and may be moved by magnetic forces.

[0036] Each of the rotary targets may be a cathode. The rotary cathodes may be electrically connected to a DC power supply. For example, components like a housing of the deposition chamber or at least one shield within the deposition chamber can be provided on mass potential. The components may serve as an anode. Optionally, a system may further include anodes. In embodiments, which can be combined with other embodiments described herein, at least one or more of the rotary targets may be electrically connected to a respective individual power supply. In particular, each of the rotary targets may be connected to a respective individual power supply. For example, the first rotary target may be connected to a first DC power supply and the second rotary target to a second DC power supply.

[0037] Particularly in embodiments where non-reactive sputtering is performed, the material to be deposited on the substrate may be sputtered from any of the first or the second rotary target. This is particularly to be understood such that particles ejected from a surface of the first or second rotary target form the deposited material. Particularly in embodiments where reactive sputtering is performed, particles of a first material may be ejected from a surface of any of the first or the second rotary target. The first material can be understood to be a component of the deposited material. A gas surrounding the first and the second rotary target may include the second material.

[0038] FIG. 2 shows some components of the system shown in FIG. 1 and includes a first graph 210 and the second graph 211 for illustrating the effect of an aperture plate (not shown in FIG. 2) according to embodiments of the present disclosure. The second rotary target is omitted in FIG. 2 for illustrating purposes only and it is to be understood that FIG. 2 relates to an FTS system. Reference is only made to the first rotary target 110 and the first magnet assembly 112 without limiting the content to the second rotary target and the second magnet assembly. The direction of plasma confinement in FIG. 2 is horizontal from left to right, for example, at the center of the first magnet assembly 112. Graph 210 shows a distribution of the deposition rate of the rotary target. The maximum deposition rate is provided from left to right. A minimum deposition rate is provided upwardly and downwardly in FIG. 2. A corresponding distribution rate on a substrate 102 during sputtering with two facing targets is shown in graph 211. The deposition rate shown by line 215 has a minimum at the center of an FTS system including a first rotary target and the second rotary target. Further, the distance of particles ejected from the target to the substrate is shown by short arrow 212 and long arrow 214. As can be seen by the length of the arrows, the travel distance is shorter for short arrow 212 adjacent to the center line 134 and is longer for long arrow 214, i.e. more distant from the center line 134.

[0039] Facing target sputtering provides for a reduced kinetic particle energy during material deposition. Placing a shielding in the center of the coactive targets according to embodiments of the present disclosure further reduces the particle energy provided on the substrate and, thus, sputter damage on sensitive layers/substrates while keeping the sputter rate at a comparably high level or as high as possible. Blocking particles along short arrow 212 with an aperture plate having a shield portion as shown in FIG. 1, reduces the number of high energetic particles, because particles along short arrow 212 have less gas interaction at a mean free path defined by other process parameters, e.g. process gas pressure. Particles with less collisions are blocked. A shielding portion at or adjacent to the center on average increases the mean free path, particularly without increasing chamber size. Further, some of the direct UV emission from the plasma region is blocked. As indicated by graph 210, the deposition rate is only reduced by a small degree, because the deposition rate in the direction of the shielding portion 150 in FIG. 1 is lower as compared to the deposition rate through the off-centric aperture. According to some embodiments, which can be combined with other embodiments described herein, the one or more apertures in the aperture plate 140 in FIG. 1 may be enlarged at a side of the aperture opposite the center line.

[0040] Without a shielding portion and/or an off-centric aperture according to embodiments of the present disclosure, the sputter rate might be reduced in order to reduce substrate damage originating from the sputter material fraction with high particle bombardment energies due to direct, short travel distance between the target surface and the substrate. The centric shielding portion blocks such high energetic bombardment particles. Accordingly, other parameters, for example, the sputter power, can be adjusted to result in higher deposition rates without damaging the substrate. Accordingly, by blocking a portion of the material with the shielding portion of the aperture plate, the overall deposition rate may be increased and, thus, the system productivity.

[0041] As described above, the mean free path sputtered material loses kinetic energy with increased travel distance to the substrate due to a higher number of collisions. According to some embodiments, which can be combined with other embodiments described herein, the high-energetic negative oxygen ions or other high energy particles can be slowed down, which can help to reduce the damage of organic layers due to sensitivity regarding oxygen. For embodiments of the present disclosure providing an off-centric LDD (LDD = Low Damage Deposition), the shorter sputter paths are blocked by one or more shielding portions. An off- centric aperture gap is provided, which includes an opening towards the substrate. The travel distance of sputtered material to the substrate is increased, particularly on average, without increasing chamber size. The ratio of the sputter rate vs. energy on the substrate that may result in damage, is increased.

[0042] As illustrated in FIG. 2, particularly with respect to graph 211, the highest plasma density provides the highest sputter rate. Due to the magnet position of an FTS system, the highest sputter rate has a wide angle relative to the center line 134 and a long travel distance towards the substrate. Due to the extended travel path at a mean free path length, which may e.g. be defined by other process parameters, the kinetic energy of sputtered material decreases with the number of collisions corresponding to the travel distance.

[0043] FIG. 1 shows a system configured for depositing material on a substrate having two apertures 140a in the aperture plate 140. According to yet further implementations, which may utilize features, details, and aspects from other embodiments described herein, a system configured for depositing material on a substrate may include one aperture 140a. The aperture plate according to some embodiments, as exemplarily shown in FIG. 1, has a symmetric arrangement relative to the shielding portion 150. The aperture plate according to some embodiments, as exemplarily shown in FIG. 3, has an asymmetric arrangement relative to the shielding portion 150.

[0044] FIG. 4A shows layers 402 deposited on a substrate 102 with a system as illustrated in FIG. 1 and described with respect to FIG. 1. FIG. 4B shows layers 402 deposited on the substrate 102 with the system as illustrated in FIG. 3 and described with respect to FIG. 3. A twin-aperture approach as shown in FIG. 1 provides a layer growth having directions with a zigzag structure. A single-aperture approach as shown in FIG. 3 provides a layer growth having a homogeneous structure as shown in FIG. 4B. However, the deposition rate is reduced by 50%.

[0045] FIGS. 5A and 5B show a further system 100 for material deposition for FTS. As indicated by the dashed arrows above the aperture plate 140, the aperture regions can be adjusted. The system includes an adjustable aperture provided in the aperture plate 140. In the context of the present disclosure, an aperture size is particularly to be understood as a size of one or more gaps and/or one or more openings in the aperture plate. The size of the one or more gaps and/or the one or more openings determine the size of the space through which particles may reach the substrate from the rotary targets. A size of the one or more apertures may be adjustable by changing a distance between shields forming the aperture plate and the shielding portion.

[0046] According to embodiments of the present disclosure, in addition to process parameters like a chamber pressure, a magnet assembly angular position, a target power, an off-centric LDD provides multiple leverages to adjust the ratio between low substrate damage at best layer quality and deposition rate. According to embodiments of the present disclosure, a further parameter is provided, wherein a ratio of the deposition rate vs. the damage to the substrate can be mechanically fine-tuned by the position of the aperture gap opening and the width of the opening.

[0047] According to some embodiments, which can be combined with other embodiments described herein, an angular position of the magnet assemblies may also be used as a process parameter. The first and the second magnet assembly may face a direction deviating from being parallel to a substrate plane by an angle of less than a first angle. The first angle may be for example 40°, 30°, 20° or 10°. In particular, the first magnet assembly faces a first direction and the second magnet assembly faces a second direction. As shown in FIG. 1, the first and the second direction may be parallel to the substrate plane. In other words, an angle of deviation from an orientation parallel to the substrate plane may be 0°. In embodiments, the first direction and the second direction deviate from being parallel to the substrate plane by an angle of less than 40°, 30° or 20° towards the substrate and less than 10° away from the substrate.

[0048] By changing the plasma confinement directions, i.e. the directions the plasma confinements are provided in, a deposition rate may be increased. A plasma confinement direction can be changed particularly by changing a position of the magnet assembly providing the plasma confinement, more particularly by rotating the magnet assembly. Changing the plasma confinement directions can also be understood as changing the sputter direction. A seed layer approach as described in more detail below can be provided according to some embodiments, which can be combined with other embodiments described herein. The seed layer approach can be further controlled by the parameter of the plasma confinement direction.

[0049] FIG. 5A shows the system for material deposition for facing target sputtering similar to the system shown in FIG. 1. The dashed arrows indicate the options of changing the size of the apertures of the aperture plate 140. FIG. 5B shows the system of FIG. 5 A, wherein the width of the shielding portion 150 has been reduced. The position of the edges of the apertures opposing the edges adjacent the shielding portion 150 are maintained as compared to FIG. 5 A.

[0050] According to some embodiments, the aperture plate 140 can include one or more adjustable apertures. This is particularly useful for a static deposition process or a batch process with a substrate movement as indicated by arrow 107. For an in-line process as indicated by arrow 105, two or more deposition operations can be provided subsequently, wherein the first deposition is provided with an aperture plate 140 shown in FIG. 5A and a second deposition is provided with an aperture plate 140 shown in FIG. 5B or another aperture plate geometry as discussed in more detail below with respect to the aperture plate geometries that can be combined with embodiments of the present disclosure. An in-line process may be particularly suitable for applications in high throughput mass production. An in-line process having a first aperture plate and the second aperture plate further includes, for example, the third rotary target with the third magnet assembly and a fourth rotary target with a fourth magnet assembly. The second aperture plate is provided between the third rotary target and the fourth rotary target and the substrate position for the second deposition.

[0051] Embodiments of the present disclosure, particularly with an adjustable aperture size and/or with different aperture sizes applied subsequently for at least a first deposition and a second deposition allow for depositing a seed layer and one or more further layers on the seed layer. The seed layer and the one or more further layers may comprise, substantially consist of or consist of the same material or the same materials.

[0052] The material deposited during the first deposition or an initial deposition generating the seed layer, particularly on an OLED material, may serve as a protection, particularly as a protective layer, before deposition is undertaken with a higher material throughput, i.e. a higher deposition rate. As compared to deposition exclusively by facing target sputtering with parameters selected for minimal damage, the deposition time can be reduced. A productivity can be increased. Substrate exposure to the deposition environment, particularly residual gas contaminants and ultraviolet radiation from sputtering, can be lowered.

[0053] For a deposition directly on a sensitive substrate, a sensitive layer, or a sensitive layer stack, for example, a substrate that may include an organic material layer, an organic material layer or a layer stack including an organic material layer, the damage of high energy particles and/or UV light is higher as compared to a further deposition on a seed layer. Accordingly, a seed layer may be deposited with a low deposition rate and with process parameters selected for low damage. After the seed layer has been deposited, the sensitivity is reduced due to a protection by the seed layer. A further deposition may be configured for higher deposition rates. According to embodiments described herein, which can be combined with other embodiments described herein, the size, position, and/or geometry of the one or more apertures in the aperture plate can be adapted. The size, position, and/or geometry of the one or more apertures can be a process parameter to adjust the energy and/or UV impact on the substrate vs. the deposition rate.

[0054] According to yet further embodiments, which can be combined with other embodiments described herein, the angular position, a sputtering power, and a chamber pressure may be used individually or in combination to further adjust the energy and/or UV impact on the substrate vs. the deposition rate

[0055] For example, in embodiments, the plasma confinement directions of the first and the second magnet assembly are changed gradually or stepwise between a first and a second deposition. In particular, positions of the first and the second magnet assembly are changed gradually or stepwise between the first and the second deposition. During a change of the plasma confinement directions, material may be deposited, particularly continued to be deposited, on the substrate. The aperture size may be changed, particularly increased, simultaneously with the change of the plasma confinement directions.

[0056] The method includes a second deposition on top of the first deposition. In particular, the second deposition provides material to a region above the material provided via the first deposition. In this regard, the term “above” particularly relates to a configuration where the substrate is located below the material provided via the first deposition. During the second deposition and optionally at least one further deposition, the plasma confinement directions and the size of the aperture can be different from during the first deposition. In embodiments, the second deposition may be provided directly on top of the first deposition.

[0057] According to an embodiment, as shown in FIGS. 5A and 5B, the width of the shielding portion 150 can be reduced. The position of the edges of the apertures opposing the edges adjacent to the shielding portion 150 can be maintained as compared to FIG. 5 A. The aperture is increased towards the center. A transition, for example a soft transition from a sensitive layer deposition to a denser layer deposition can be provided. The increasing aperture size provides for a comparably high deposition rate.

[0058] According to an embodiment, as indicated by the arrows shown in FIG. 5 A, the aperture can be maintained in size by reducing the size of the shielding portion at a center line 134 and moving the outer edges of the aperture by the same distance, e.g. towards the center. Further, the aperture and intermediate scenario between FIG. 5B and maintaining the size can be provided by reducing the size of the shielding portion and moving the outer edges of the aperture by a smaller distance towards the center as compared to the inner edges, i.e. the movement of the inner edges corresponding to the size reduction of the shielding portion. A transition, for example a soft transition from sensitive layer deposition to denser layer deposition can be provided. The medium deposition rate is provided.

[0059] Yet further, the size of the shielding portion can be reduced and the aperture size of the two apertures shown in FIG. 5A can be reduced by moving the outer edges by a larger distance towards the center as compared to the inner edges, i.e. the movement of the inner edges corresponding to the size reduction of the shielding portion. The strong transition with the focus on dense layer deposition can be provided, for example, at a low deposition rate.

[0060] As described above, the aperture plate according to embodiments described herein having a center shielding portion and/or off-centric one or more apertures provides a process parameter to adjust the transition between sensitivity and layer density. Corresponding deposition rates are provided. Further, the center shielding portion blocks high-energy particles and/or UV light to reduce the damage on the substrate while not significantly reducing the deposition rate. The ratio of the deposition rate vs. the damage can be increased. [0061] FIGS. 6 A and 6B show a system for layer deposition with FTS and relate to corresponding methods for layer deposition similar to FIGS. 5 A and 5B, yet with a single aperture approach as previously discussed with respect to FIGS. 3 and 4B. FIG. 6A shows the system for material deposition for facing target sputtering similar to the system shown in FIG. 3. The dashed arrows indicate the options of changing the size of the apertures of the aperture plate 140. FIG. 6B shows the system of FIG. 6A, wherein the width of the shielding portion 150 has been reduced, particularly towards the center line 134. The position of the edges of the aperture opposing the edge adjacent the shielding portion 150 are maintained as compared to FIG. 6A.

[0062] According to some embodiments, the aperture plate 140 can include adjustable apertures. This is particularly useful for a static deposition process or a batch process with a substrate movement as indicated by arrow 107. For an in-line process as indicated by arrow 105, two or more deposition operations can be provided subsequently, wherein the first deposition is provided with an aperture plate 140 shown in FIG. 6A and a second deposition is provided with an aperture plate 140 shown in FIG. 6B or another aperture plate geometry. Details, aspects and features that are described with respect to the twin-aperture embodiments explained in reference to FIGS. 5 A and 5B similarly apply for the single aperture configuration shown in FIGS. 6 A and 6B.

[0063] As described above, embodiments of the present disclosure, particularly with an adjustable aperture size and/or with different aperture sizes applied subsequently for at least a first deposition and a second deposition allow for depositing a seed layer and one or more further layers on the seed layer. The seed layer and the one or more further layers may comprise, substantially consist of or consist of the same material or the same materials.

[0064] According to an embodiment, as shown in FIGS. 6 A and 6B, the width of the shielding portion 150 can be reduced. The position of the edges of the apertures opposing the edges adjacent to the shielding portion 150 can be maintained as compared to FIG. 5 A. According to an embodiment, as indicated by the arrows shown in FIG. 6A, the aperture can be maintained in size by reducing the size of the shielding portion at a center line 134 and moving the outer edges of the aperture by the same distance, e.g. towards the center. Further, the aperture and intermediate scenario between FIG. 6B and maintaining the size can be provided by reducing the size of the shielding portion and moving the outer edges of the aperture by a smaller distance towards the center as compared to the inner edges, i.e. the movement of the inner edges corresponding to the size reduction of the shielding portion. Yet further, the size of the shielding portion can be reduced and the aperture size of the two apertures shown in FIG. 6A can be reduced by moving the outer edges by a larger distance towards the center as compared to the inner edges, i.e. the movement of the inner edges corresponding to the size reduction of the shielding portion. Similar transitions relating the sensitivity, layer density and/or deposition rates as described for the twin-aperture design apply for the single-aperture design.

[0065] As described above, the aperture plate according to embodiments described herein having a center shielding portion and/or off-centric one or more apertures provides a process parameter to adjust the transition between sensitivity and layer density. Corresponding deposition rates are provided. Further, the center shielding portion blocks high-energy particles and/or UV light to reduce the damage on the substrate while not significantly reducing the deposition rate. The ratio of the deposition rate vs. the damage can be increased.

[0066] In embodiments, an aperture size for a seed layer deposition or a first deposition can be smaller than a first size. The first size can be for example 40 mm, 70 mm, 100 mm, or 130 mm. The first aperture may have a size of for example 30 mm, 50 mm, or 70 mm. The first aperture may have a size larger than for example 5 mm, 15 mm, or 20 mm.

[0067] In embodiments, magnets included in each of the magnet assemblies may deviate from being parallel to each other. In other words, magnets of each of the magnet assemblies may enclose an opening angle. In particular, at least one of the magnets may deviate from being parallel to the center axis or symmetry axis of the magnet assembly by an angle of more than for example 3, 6, or 10°. The at least one magnet may deviate from being parallel to the center axis or symmetry axis by an angle of less than for example 30°, 25°, or 15°.

[0068] According to some embodiments, a system 100 for material deposition with FTS further includes a controller configured to control the system such that a method of depositing at least one material on a substrate, as described herein, is performed. The method may be particularly suitable for a batch-type deposition system or an in-line deposition system. [0069] The controller may include a central processing unit (CPU), a memory and, for example, support circuits. To facilitate control of the system, the CPU may be one of any form of a general-purpose computer processor that can be used in an industrial setting for controlling various components and sub -processors. The memory is coupled to the CPU. The memory, or a computer readable medium, may be one or more readily available memory devices such as random-access memory, read only memory, a hard disk, or any other form of digital storage either local or remote. The support circuits may be coupled to the CPU for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry and related subsystems, and the like.

[0070] Control instructions are generally stored in the memory as a software routine or program. The software routine or program may also be stored and/or executed by a second CPU that is remotely located from the hardware being controlled by the CPU. The software routine or program, when executed by the CPU, transforms the general -purpose computer into a specific purpose computer (controller) that controls a system for depositing a material, according to any of the embodiments of the present disclosure.

[0071] Methods of the present disclosure may be implemented as a software routine or program. At least some of the method operations disclosed herein may be performed via hardware as well as by a software controller. As such, the embodiments may be implemented in software as executed upon a computer system, and hardware as an application specific integrated circuit or another type of hardware implementation, or a combination of software and hardware. The controller may execute or perform a method of depositing a material on a substrate, according to embodiments of the present disclosure. Methods described herein can be conducted using computer programs, software, computer software products and interrelated controllers, which can have a CPU, a memory, a user interface, and input and output devices being in communication with corresponding components of the system for depositing a material.

[0072] For example, when depositing electrodes of an OLED, the material may have to be deposited on a highly sensitive layer. For some materials, particularly transparent conductive oxides or metal oxides, soft deposition via conventional technology like evaporation may be impossible. Embodiments of the present disclosure employ a facing target design to solve this. By using rotary targets, in line with embodiments of the present disclosure having an aperture plate with a shielding portion, particularly a central shielding portion, a deposition rate vs. damage ratio can be improved. For FTS with rotary targets, target surface contamination may be mitigated and system up-times may be increased. Further, as described herein, a number of high-energy particles, like sputter particles, negative ions, electrons impinging on the substrate and UV light may be reduced.

[0073] FIG. 7 shows a method of depositing a material on a substrate. At operation 702, material is sputtered from a first rotary target having a first magnet assembly with the first plasma confinement. The material is sputtered with an aperture plate, for example, through an aperture of the aperture plate. At operation 704, material is simultaneously sputtered from a second target having a second magnet assembly with the second plasma confinement. The material is sputtered with the aperture plate. The first plasma confinement faces the second rotary target and the second plasma confinement faces the second rotary target. The plasma confinements face the respective opposite target and/or face each other. The aperture plate has a body with a shielding portion. For example, the shielding portion can be at least at the center line, i.e. a center line perpendicular to the substrate surface at a plasma region between the rotary targets.

[0074] According to some embodiments, which can be combined with other embodiments described herein, the size and/or position of the one or more apertures relative to the center line can be adapted for the second position operation, as illustrated by operation 706 in FIG. 7.

[0075] The first plasma confinement is in a first direction and the second plasma confinement is in a second direction, the first direction and the second direction deviating from being parallel to a substrate plane of the substrate by an angle of less than an angle of 20°, particularly by less than an absolute value of 20°. For example, the first direction and the second direction of the first plasma confinement or the second plasma confinement, respectively can be changed, particularly for a further material deposition and more particularly beyond the angle.

[0076] The aperture plate includes one or more apertures for trespassing of the material. The one or more apertures can be offset from the center line. At least one of the size and the position of the one or more apertures can be changed between a first deposition and a second deposition. The one or more apertures can be two or more apertures. For example, two apertures are arranged on opposing sides of the shielding portion.

[0077] Methods according to embodiments described herein, which can be combined with other embodiments described herein, may include sputtering a layer stack. The layer stack may include a metal and a transparent conductive oxide (TCO) deposited on the metal. For example, the layer stack may include Ag deposited on IZO. During sputtering of the metal, the magnet assemblies may be in a facing target sputtering (FTS) configuration and a shielding portion at the center line, particularly to provide a soft deposition. A soft deposition may be understood as a deposition according to features of the first deposition of the method.

[0078] The TCO may be deposited partly with the magnet assemblies in an FTS configuration and partly with the magnet assemblies in a direct sputtering configuration. Partly depositing the TCO with magnet assemblies in an FTS configuration may be understood as performing a seed deposition. In particular, material deposited during the seed deposition is part of the final TCO layer after completion of the full deposition.

[0079] A layer stack may include a first metal layer and a second metal layer deposited on the first metal layer. The layer stack may further include a TCO deposited on the second metal. As an example, the first metal can be Li, Ca, Yb, or AgMg, the second metal Ag, and the TCO may be IZO.

[0080] A layer stack may include a first metal oxide layer and a second metal oxide layer. The first and the second metal oxide can be different materials or the same material but with differing stoichiometries. As an example, the first and the second metal oxide layers may be respectively stoichiometrically different IGZO or IGZTO layers or the stack may be an IZO followed by IGZO.

[0081] A layer stack may include a first TCO layer, a metal layer deposited on the first TCO layer, and a second TCO layer deposited on the metal layer. For example, the first TCO layer and the metal layer may be deposited with magnet assemblies in an FTS configuration. The second TCO layer may be deposited partly in an FTS configuration and partly in a direct sputtering configuration. [0082] In embodiments, metals are deposited with magnet assemblies in an FTS configuration. Metal oxides may be deposited for example with magnet assemblies in an FTS configuration. Alternatively, metal oxides may be deposited partly with magnet assemblies in an FTS configuration and partly with magnet assemblies in a direct sputtering configuration.

[0083] In the context of the present disclosure, depositing a material is particularly to be understood as depositing a single layer. The single layer may be deposited partly with different deposition system configurations, for example, different aperture sizes and/or positions. The single layer may be deposited partly via at least one different deposition source. Within a single layer, the material properties may be at least substantially homogeneous.

[0084] Some embodiments described herein may 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 of a corresponding size have a plurality of substrates, may have a size of at least 0.67 m ² Typically, the size can be about 0.67m ² (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. According to some embodiments, which can be combined with other embodiments described herein, systems for material deposition and methods for material deposition according to embodiments described herein, may also relate to wafer processing and smaller substrate sizes and/or carrier sizes (or substrate pedestal sizes) of 0.04 m ² or above.

[0085] While the foregoing is directed to some embodiments, other and further embodiments may be devised without departing from the basic scope of the disclosure. The scope is determined by the following claims.