WO2020244781A1

WO2020244781A1 - Deposition source, deposition apparatus and method of depositing material on a substrate

Info

Publication number: WO2020244781A1
Application number: PCT/EP2019/064985
Authority: WO
Inventors: Sebastian Franke; Andreas Lopp; Andreas MÜLLER; Stefan Bangert; Stefan Keller; Wolfgang Buschbeck
Original assignee: Applied Materials, Inc.
Priority date: 2019-06-07
Filing date: 2019-06-07
Publication date: 2020-12-10

Abstract

A deposition source (100) for depositing material on a substrate (10) is described. The deposition source (100) includes a sputter source (110). Further, the deposition source (100) includes a reflector shield arrangement (120) for reflecting material provided from the sputter source towards the substrate. Further, a deposition apparatus and a method of depositing material on a substrate are described.

Description

DEPOSITION SOURCE, DEPOSITION APPARATUS AND METHOD OF DEPOSITING MATERIAL ON A SUBSTRATE

TECHNICAL FIELD

[1] Embodiments of the present disclosure relate to material deposition, particularly layer deposition, by sputtering. Specifically, embodiments relate to deposition sources, deposition apparatuses and methods of depositing material by sputtering on a substrate in a vacuum environment. In particular, embodiments of the present disclosure are suitable for the production of organic light-emitting diodes (OLEDs).

BACKGROUND

[2] Several methods are known for depositing a material on a substrate. For instance, substrates can be coated by a physical vapor deposition (PVD) process, such as sputtering, a chemical vapor deposition (CVD) process, or a plasma enhanced chemical vapor deposition (PECVD) process. Typically, the process is performed in a deposition apparatus including a vacuum chamber, where the substrate to be coated is located. A deposition material is provided in the apparatus. The deposition material may, e.g., be sputtered from a sputter target toward the substrate to be coated. A plurality of materials may be used for deposition on a substrate. Among them, many different metals can be used, but also oxides, nitrides or carbides. Typically, a sputter process is suitable for thin film coatings.

[3] Known sputter deposition sources include a power supply arrangement with a power supply for generating and supplying electric energy to one or more electrodes, e.g. cathodes, of the sputter deposition source. Said energy is deposited in a gas between the cathodes for igniting and maintaining a plasma, and the motion of the plasma ions and plasma electrons may be controlled by magnet assemblies. The cathodes may include a respective target for providing the coating material through sputtering by the plasma. [4] Coated substrates can be used in several applications and in several technical fields. For instance, an application lies in the field of microelectronics, such as generating semiconductor devices. Also, substrates for displays are often coated by a PVD process, wherein large area substrates are processed.

[5] However, sputter deposition typically involves high energy sputtered particles which may damage sensitive surfaces onto which the material is to be deposited. Accordingly, there is a limitation with respect to the substrate materials which can be coated by sputtering. In other words, a prerequisite for applying coatings by sputter deposition is a relatively robust substrate being resistant with respect to high energy sputtered particles. Since polymers and smaller organic molecules are extremely sensitive to high energy particles, sputtering is usually not suitable to deposit inorganic materials onto organic films for OLED fabrication.

[6] OLEDs are a special type of light-emitting diode in which the emissive layer comprises a thin film of certain organic compounds. OLEDs are used in the manufacture of television screens, computer monitors, mobile phones, other hand held devices, etc., for displaying information. OLEDs can also be used for general space illumination. For the production of organic light-emitting diodes (OLEDs), organic and metal evaporators are typically used. However, in some aspects, evaporation deposition techniques have some disadvantages compared to sputter deposition techniques, e.g. with respect to controlling the deposition rate.

[7] Accordingly, there is an increasing demand to provide improved deposition techniques for applying coatings on sensitive substrates or on substrates with pre-coated sensitive layers, particularly for OLED and MicroLED fabrication. SUMMARY

[8] In light of the above, a deposition source, a deposition apparatus, and a method of depositing 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.

[9] According to an aspect of the present disclosure, a deposition source for depositing material on a substrate is provided. The deposition source includes a sputter source and a reflector shield arrangement for reflecting material provided from the sputter source towards the substrate. [10] According to another aspect of the present disclosure, a deposition apparatus is provided. The deposition apparatus includes a vacuum chamber and at least one deposition source for depositing material on a substrate provided in the vacuum chamber. The at least one deposition source includes a sputter source and a reflector shield arrangement for reflecting material provided from the sputter source towards the substrate. In particular, the at least one deposition source is a deposition source according to any embodiments described herein.

[11] According to a further aspect of the present disclosure, a method of depositing material on a substrate is provided. The method includes sputtering material from a sputter source towards a reflector shield arrangement. Further, the method includes reflecting the material from the reflector shield arrangement towards the substrate.

[12] According to a yet further aspect of the present disclosure, a method of manufacturing a device is provided. The method includes using the deposition source according to any embodiments described herein. Additionally or alternatively, the method of manufacturing the device includes using the method of depositing material on a substrate according to any embodiments described herein. [13] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing the described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed at methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS [14] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following: FIG. 1 shows a schematic view of a deposition source for depositing material on a substrate according to embodiments described herein;

FIGS. 2 to 7 show schematic views of a deposition source for depositing material on a substrate according to further embodiments described herein;

FIG. 8 shows a schematic view of a deposition apparatus according to embodiments described herein;

FIGS. 9 A and 9B show flowcharts for illustrating a method of depositing material on a substrate according to embodiments described herein; and

FIG. 10 shows a flowchart for illustrating a method of manufacturing a device according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS [15] Reference will now be made in detail to the various embodiments of the disclosure, 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. Only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. 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.

[16] With exemplary reference to FIG. 1, a deposition source 100 for depositing material on a substrate 10 according to the present disclosure is described. According to embodiments which can be combined with other embodiments described herein, the deposition source 100 includes a sputter source 110. In particular, the sputter source is configured for sputtering a material to be deposited. Further, the deposition source 100 includes a reflector shield arrangement 120 for reflecting material provided from the sputter source 110 towards the substrate 10. In particular, the reflector shield arrangement 120 is arranged opposite a sputter side 111 of the sputter source 110, as exemplarily shown in FIG. 1. The dotted arrows in FIG. 1 schematically represent the sputtered material. As shown in FIG. 1, the sputter side 111 of the sputter source 110 faces the reflector shield arrangement 120. The reflector shield arrangement 120 is configured for reflecting the sputtered material towards the substrate 10. Accordingly, the material to be deposited is indirectly provided from the sputter source to the substrate, namely via reflection on the reflector shield arrangement 120. In other words, the material to be deposited being provided by the sputter source 110 is directed towards the reflector shield arrangement 120 and the reflector shield arrangement 120 reflects the material towards the substrate.

[17] It is to be noted that FIGS. 1 to 7 show schematic top views of embodiments of a deposition source as described herein. Further, in the right bottom comer of FIGS. 1 to 7, the front direction F, the back direction B, and the lateral side directions L of the deposition source are indicated. The front direction F of the deposition source is the direction towards the substrate to be coated. Typically, the front direction F of the deposition source corresponds to the deposition direction of the deposition source. Accordingly, it is to be understood that the back direction B of the deposition source is the direction opposite to the front direction F. As exemplarily shown in FIGS. 1 to 5, the sputter source 110 is configured for sputtering material in the back direction B of the deposition source 100. The reflector shield arrangement 120 is configured for reflecting the sputtered material in the front direction F of the deposition source 100.

[18] Accordingly, embodiments of the deposition source as described herein are improved compared to conventional sputter deposition sources. In particular, embodiments of the deposition source as described herein are suitable for applying coatings on sensitive substrates (or on substrates with pre-coated sensitive layers) by using sputter techniques. More specifically, the configuration of the deposition source as described herein has the advantage that the energy of the sputtered particles is thermalized before the sputtered particles reach the substrate. In this regard, it is to be understood that“thermalization” is the process of physical bodies (here sputtered particles) reaching thermal equilibrium through mutual interaction (here interaction of the sputtered particles with the reflector shield arrangement).

[19] Accordingly, the deposition source of the present disclosure beneficially provides for an improved sputter deposition technique based on a sputter process in which the sputtered particles are have thermalized have lower energies compared to conventional sputter deposition sources. In particular, by employing a deposition as described herein, the particle energy can be thermalized to about ~0.1 eV before reaching the substrate. In this regard, it is to be noted that in a sputter process a multitude of high energetic particles such as VUV photons, reflected neutrals, electrons and ions as well as excited atoms are formed. Those particles typically have energies in the range of 10 to 500 eV. As polymers and smaller organic molecules are very sensitive to high energy particles, a sputter process of metals and transparent conductive oxides (TCOs) is usually not compatible with polymers and organic materials, e.g. as typically used in OLED fabrication.

[20] Accordingly, compared to the state of the art, the deposition source as described herein has the advantage that substantially no high energetic particles reach the substrate. Thus, the sputter deposition source as described herein is beneficially compatible with OLED fabrication.

[21] Further, compared to conventional deposition sources used in OLED fabrication, e.g. having a crucible for evaporating the material to be deposited and a distribution pipe for providing the evaporated material to the substrate, the deposition source according to embodiments described herein has the following advantages. Since the deposition rate is correlated with the sputter power, a separate deposition rate measurement device, e.g. a quartz crystal microbalance (QCM) can be omitted. Additionally, the deposition source according to embodiments described herein provides for a direct response, i.e. the applied power directly translates to the deposition rate such that there is substantially no delay for establishing a thermal equilibrium as typically present in conventional deposition sources for OLED production. Further, the deposition source as described herein beneficially provides for the possibility to sputter composite materials, e.g. Ag/Mg, from a single target.

[22] Before various further embodiments of the present disclosure are described in more detail, some aspects with respect to some terms used herein are explained.

[23] In the present disclosure, a“deposition source” can be understood as a device or assembly configured for depositing material, particularly sputtered material, on a substrate. For example, the material to be deposited on a substrate can be suitable for forming a layer on the substrate, particularly an optically active layer. Typically, the material to be deposited is a material used in manufacturing of electronic devices, particularly optoelectronic devices, such as displays. For instance, the material to be deposited can be a material usable for OLED display manufacturing. Examples for the material to be deposited include one or more of the following: ITO, IGZO, ZAO, LiF, and metals such as aluminum, gold, ytterbium, silver or magnesium. Typically, the deposition source as described herein includes a sputter source for providing the material to be deposited. As described herein, the deposition source of the present disclosure is configured for indirect sputter deposition, i.e. thermalized sputter deposition, e.g. via reflection of the sputtered material on a reflector shield arrangement.

[24] In the present disclosure, a“sputter source” can be understood as a device configured for sputtering material. A sputter source may include a sputter target, particularly a rotatable target. A rotatable target may be rotatable around an axis. A rotatable target may have a curved surface, for example a cylindrical surface. The rotatable target may be rotated around the rotation axis being the axis of a cylinder or a tube during sputtering. This may increase material utilization. Alternatively, the sputter source may include a flat or planar target as exemplarily described with reference to FIG. 7. Further, it is to be understood that the sputter source as described herein may be a sputter source configured for reactive sputtering, e.g. for the production of uLEDs. For instance, in reactive sputter processes, nitrogen N₂ may be added to a process gas, e.g. argon Ar. More specifically, the sputter source as described herein can be configured for epitaxial deposition of one or more of GaN, InGaN, AlGaN, AIN on a substrate, particularly substrates includes or consisting of sapphires, by reactive sputtering.

[25] Further, as exemplarily shown in FIG. 2, the sputter source 110 may include a magnet assembly 112 for generating a magnetic field during operation of the sputter source. For instance, the magnet assembly may be arranged inside the rotatable target of the sputter source. In cases where a magnet arrangement is provided in the rotatable target, the sputter source may be referred to as a sputter magnetron. The magnet assembly can generate a magnetic field. The magnetic field may cause one or more plasma regions to be formed near the magnetic field during the sputtering. The magnet assembly may be movable inside the rotatable target. The position of the magnet assembly within the rotatable sputter target affects the direction in which target material is sputtered away from the cathode assembly. Typically, the magnet assembly 112 is configured to confine a plasma 115 on the sputter side 111 of the sputter source 110, as exemplarily shown in FIG. 2. For instance, the sputter source can include a rotary cathode as exemplarily shown in FIGS. 1 to 6. Alternatively, the sputter source may include a planar cathode as exemplarily shown in FIG. 7.

[26] In the present disclosure, the term“substrate” may particularly embrace substantially inflexible substrates, e.g., a wafer, slices of transparent crystal such as sapphire or the like, or a glass plate. However, the present disclosure is not limited thereto, and the term“substrate” may also embrace flexible substrates such as a web or a foil. The term“substantially inflexible” is understood to distinguish over“flexible”. Specifically, a substantially inflexible substrate can have a certain degree of flexibility, e.g. a glass plate having a thickness of 0.5 mm or below, wherein the flexibility of the substantially inflexible substrate is small in comparison to the flexible substrates. According to embodiments described herein, the substrate may be made of any material suitable for material deposition. For instance, the substrate may be made of a material selected from the group consisting of glass (for instance soda-lime glass, borosilicate glass etc.), metal, polymer, ceramic, compound materials, carbon fiber materials or any other material or combination of materials which can be coated by a deposition process.

[27] Embodiments described herein particularly relate to deposition on large area substrates. For instance, a“large area substrate” can have a main surface with an area of 0.5 m² or larger, particularly of 1 m² or larger. In some embodiments, a large area substrate can be GEN 4.5, which corresponds to about 0.67 m² of substrate (0.73 x 0.92m), GEN 5, which corresponds to about 1.4 m² of substrate (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m² of substrate (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7 m² of substrate (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m² of substrate (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.

[28] In the present disclosure, a “reflector shield arrangement” can be understood as an arrangement configured for reflecting sputtered material provided from the sputter source. In particular, the reflector shield arrangement has at least one surface facing a sputter side of the sputter source. More specifically, the reflector shield arrangement may have one or more surfaces which are configured and arranged for reflecting the sputtered material provided from the sputter source towards the substrate.

[29] More specifically, as exemplarily shown in FIG. 2, according to embodiments which can be combined with other embodiments described herein, the reflector shield arrangement 120 typically includes a first reflector surface 121 facing a sputter side 111 of the sputter source 110. As exemplarily shown in FIG. 2, the first reflector surface 121 may be directed towards the front direction F of the deposition source. Further, the reflector shield arrangement 120 may include a second reflector surface 122 facing a lateral side of the sputter source 110. For instance, the reflector shield arrangement 120 may include a back reflector shield 133 provided at a back side of the deposition source. As exemplarily shown in FIG. 2, the back reflector shield 133 may provide the first reflector surface 121. Further, the reflector shield arrangement 120 may include lateral side reflector shields 131. The lateral side reflector shields 131 may face the lateral sides of the sputter source 110 and provide the second reflector surfaces 122.

[30] With exemplary reference to FIG. 2, according to embodiments which can be combined with other embodiments described herein, the reflector shield arrangement 120 includes a heating device 130. The heating device 130 is configured for heating the reflector shield arrangement 120, particularly the reflector surfaces of the reflector shield arrangement. Providing a heating device 130 may be beneficial for avoiding deposition of the sputtered material on the reflector shield arrangement. In particular, condensation of the sputtered material on the reflector shield arrangement and thus adsorption on the reflector shield arrangement can be avoided. Accordingly, it is to be understood that typically the heating device is configured for heating the reflector shield arrangement to a temperature equal to or above the condensation temperature of the sputtered material. In other words, typically, the heating device is configured for heating the reflector shield arrangement up to at least the evaporation temperature of the sputtered material provided from the sputter source. For instance, the heating device may be configured for heating the reflector shield arrangement up to a temperature of 1000°C or more. According to an example, the heating device may include one or more ceramic heaters. Accordingly, it is to be understood that the reflector shield arrangement is typically made of a temperature resistant material which withstands the temperatures occurring during operation of the deposition source.

[31] According to embodiments which can be combined with other embodiments described herein, the reflector shield arrangement 120 includes an aperture 126 for directing material reflected from the reflector shield arrangement 120 towards the substrate 10. The aperture 126 may be provided as a free space provided between the reflector shield arrangement 120 and the sputter source 110. In particular, aperture 126 may correspond to the free space provided between lateral side reflector shields 131 of the reflector shield arrangement 120 and the lateral outer contour of the sputter source 110, as exemplarily indicated in FIG. 2. Alternatively, the aperture 126 may be an opening provided in a front reflector shield 132, as shown in FIGS. 5 to 7.

[32] According to embodiments which can be combined with other embodiments described herein, the reflector shield arrangement 120 includes at least one shell-like reflector shield 125. For instance, the reflector shield arrangement 120 may have a C-shape with an opening towards the substrate as exemplarily shown in FIGS. 1 to 3. For example, the shell-like reflector shield 125 may have a substantially rectangular shape as exemplarily shown in FIGS. 1 and 2. Alternatively, the shell-like reflector shield 125 may be round as exemplarily shown in FIGS. 3 and 4. In particular, the shell-like reflector shield 125 can be a half-shell, e.g. a half-circular shell or a half oval shell. In particular, the at least one shell-like reflector shield 125 may have a concave reflector surface 127 facing the sputter source 110, as exemplarily shown in FIG. 3.

[33] With exemplarily reference to FIG. 4, according to embodiments which can be combined with other embodiments described herein, the at least one shell like reflector shield 125 includes a first shell-like reflector shield 128 and a second shell-like reflector shield 129. In particular, the first shell-like reflector shield 128 and the second shell- like reflector shield 129 may have substantially elliptic reflector surfaces. As exemplarily shown in FIG. 4, the first shell-like reflector shield 128 and the second shell-like reflector shield 129 may be arranged mirror- symmetrically to each other. In particular, the first shell-like reflector shield 128 and the second shell-like reflector shield 129 may be arranged mirror- symmetrically with respect to a central axis 11 of the sputter source 110, as exemplarily shown in FIG. 4. Providing a reflector shield arrangement 120 as schematically shown in FIG.4 may be beneficial for increasing the deposition efficiency. The two plasma zones 115A indicated in FIG. 5 result from the arrangement of a total of 3 magnet systems with the orientation A B A as exemplarily depicted in FIG 4, wherein A and B represent the orientation of the magnetic field (e.g. north-south-north or vice versa). This magnet arrangement results in an increased plasma density between the magnets which can lead to sputter ditches on the target.

[34] With exemplarily reference to FIG. 5, according to embodiments which can be combined with other embodiments described herein, the reflector shield arrangement 120 may be provided around the sputter source 110. For example, the reflector shield arrangement 120 may be configured as casing or housing provided around the sputter source 110. As exemplarily shown in FIG. 5, the reflector shield arrangement 120 can include a front reflector shield 132 and a back reflector shield 133 which can be connected via side reflector shields 131. The front reflector shield 132 typically includes an aperture 126 for directing the material reflected from the reflector shield arrangement 120 towards the substrate 10. In particular, the front reflector shield 132 may include two or more apertures, particularly a plurality of apertures, provided along a length of the deposition source. In the embodiments shown in FIGS. 1 to 7, the length direction of the deposition source corresponds to the direction into and out of the paper plane. Typically, the one or more apertures provided in the front reflector shield 132 include a nozzle 140.

[35] With exemplary reference to FIG. 6, according to embodiments which can be combined with other embodiments described herein, the sputter source 110 may extend through the back reflector shield 133. In other words, the back reflector shield 133 may include a mounting opening for the sputter source 110. As exemplarily shown in FIG. 6, the sputter side 111 of the sputter source may face a first reflector surface 121 provided by the front reflector shield 132. Further, as exemplarily shown in FIG. 6, a back side of the sputter source 110 may be arranged in a separate housing 135 in which a process gas can be provided. The separate housing 135 can be connected to the back reflector shield 133. The embodiment as exemplarily shown in FIG. 6 has the advantage that the risk of target melting can be reduced.

[36] With exemplary reference to FIG. 7, according to embodiments which can be combined with other embodiments described herein, the sputter source includes a flat or planar cathode having a planar target. A flat or planar cathode is typically more cost-efficient compared to a rotary cathode. Further, compared to the embodiment as exemplarily shown in FIG. 6, the embodiment of FIG. 7 may have the advantage that, due to self-sputtering of the target material, a process gas may not be needed. Further, it is to be understood that, since the vacuum chamber 210 of the deposition apparatus (exemplarily described with reference to FIG. 8) typically includes an ultra-high vacuum (UHV), it is possible to combine one or more evaporation sources with one or more sputter deposition sources as described herein within the same vacuum chamber. [37] From FIGS. 5 to 7 it is to be understood that the heating device 130 may include individual heating elements provided on respective reflector shields of the reflector shield arrangement. Accordingly, the front reflector shield 132 and/or the back reflector shield 133 and/or the side reflector shields 131 may be provided with respective heating elements.

[38] With exemplary reference to FIG. 8, a deposition apparatus 200 according to the present disclosure is described. According to embodiments which can be combined with other embodiments described herein, the deposition apparatus 200 includes a vacuum chamber 210, particularly an ultra-high vacuum (UHV) chamber, and at least one deposition source 220 for depositing material on a substrate 10. Typically, the at least one deposition source 220 is provided in the vacuum chamber 210.

[0001] The at least one deposition source 220 is configured for coating the substrate 10 that is arranged on a front side of the at least one deposition source 220. The front side of the at least one deposition source is the side towards which the material is provided from the deposition source. For example, a substrate transport track 230 for transporting the substrate 10 into and out of the vacuum chamber 210 may be provided in front of the at least one deposition source 220, as schematically indicated in FIG. 8. [39] The at least one deposition source includes a sputter source and a reflector shield arrangement for reflecting material provided from the sputter source towards the substrate. In particular, the at least one deposition source 220 is a deposition source 100 according to any embodiments described herein, as exemplarily described with reference to FIGS. 1 to 7. [40] In particular, as exemplarily shown in FIG. 8, the deposition apparatus 200 may include an array of deposition sources. Typically, the individual deposition sources of the array of deposition sources are arranged along a line substantially parallel to a horizontal substrate orientation. The horizontal substrate orientation typically corresponds to a substrate transport direction T, as exemplarily indicated in FIG. 8. Further, it is to be understood that, although not explicitly shown in FIG. 8, the vacuum chamber of the deposition apparatus may include one or more evaporation sources in combination with one or more sputter deposition sources as described herein. Accordingly, deposition of composites or alloys from several sources can be realized, such that the composition of a deposition layer can be freely selectable.

[41] For illustrative purposes, FIG. 8 shows an example of an array of three deposition sources. However, it is to be understood that more deposition sources can be provided, e.g. an array of four, eight, twelve, sixteen or more deposition sources, which may be arranged spaced apart from each other in an essentially linear setup (i.e., a line array of deposition sources).

[42] The deposition apparatus 200 may be configured for static deposition. In other words, the substrate can be positioned in front of the at least one deposition source 220 and held essentially stationary during the deposition. Alternatively, the deposition apparatus may be configured for dynamic deposition, wherein the substrate and the at least one deposition source are moved relative to each other during the deposition. For instance, the substrate may be moved relative to the at least one deposition source or vice versa.

[43] Typically, the vacuum chamber 210 is sized to accommodate a rectangular vertically arranged substrate, particularly a large area substrate, as described herein. The substrate may be carried by a substrate carrier during transport and/or during the processing.

[44] With exemplary reference to the flowcharts shown in FIGS. 9A and 9B, a method 300 of depositing material on a substrate according to the present disclosure is described. According to embodiments which can be combined with other embodiments described herein, the method 300 includes sputtering (represented by block 301 in FIG. 9A) material from a sputter source towards a reflector shield arrangement. Additionally, the method 300 includes reflecting sputtering (represented by block 302 in FIG. 9A) the material from the reflector shield arrangement towards the substrate. Accordingly, the method of depositing material on a substrate as described herein is an indirect deposition method. In other words, the method includes indirectly depositing material, particularly by reflecting the material provided from the sputter source on a reflector shield arrangement 120. The reflector shield arrangement 120 is arranged and configured for directing the material via reflection towards the substrate. Accordingly, the method of depositing material as described herein beneficially provides for thermalization of sputtered particles, particularly to about ~0.1 eV, before the particles reach the substrate. Thus, a sputter deposition method is provided with which deposition on substrates of sensitive materials (e.g. materials including polymeric or organic materials) is possible without causing damage to such substrates. Hence, the sputter deposition method as described herein is particularly well suited for OLED fabrication.

[45] With exemplary reference in FIG. 9B, according to embodiments which can be combined with other embodiments described herein, the method 300 may further include heating (represented by block 303 in FIG. 9B) the reflector shield arrangement. Heating the reflector shield arrangement may be beneficial for avoiding deposition of the sputtered material on the reflector shield arrangement. In particular, condensation of the sputtered material on the reflector shield arrangement and thus adsorption on the reflector shield arrangement can be avoided. Accordingly, it is to be understood that typically heating the reflector shield arrangement includes heating the reflector shield arrangement to a temperature equal to or above the condensation temperature of the sputtered material. In other words, the reflector shield arrangement may be heated to at least the evaporation temperature of the sputtered material provided from the sputter source.

[46] Additionally, the method 300 may include guiding (represented by block 304 in FIG. 9B) the material reflected from the reflector shield arrangement 120 through an aperture 126 directed towards the substrate 10. As exemplarily shown in FIGS. 1 to 7, the aperture 126 faces the substrate onto which the material is to be deposited. For instance, the aperture can be provided by a free space between the sputter source and side reflector shields, as exemplarily shown in FIGS. 1 to 4. Alternatively, the aperture may be provided in a front reflector shield, as exemplarily shown in FIGS. 5 to 7. [47] Accordingly, it is to be understood that the method 300 typically includes using a deposition source 100 according to any embodiments described herein.

[48] Further, according to embodiments which can be combined with other embodiments described herein, sputtering may include reactive sputtering, particularly adding nitrogen to a process gas. Typically, the process gas includes mainly argon or consists of argon. For example, reactive sputtering can be carried out for the production of uLEDs. More specifically reactive sputtering may include epitaxially depositing one or more of GaN, InGaN, AlGaN, AIN on a substrate, particularly substrates including or consisting of sapphires.

[49] With exemplary reference to the flowchart shown in FIG. 10, a method 400 of manufacturing a device, particularly an optoelectronic device is described.

Typically, the method 400 includes using a deposition source (represented by block 401) according to any embodiments described herein. Additionally or alternatively, the method 400 includes using a method 300 of depositing material on a substrate according to any embodiments described herein (represented by block 402). Accordingly, beneficially a device can be manufactured having a sputtered coating or layer provided on a sensitive material (e.g. a polymeric material or other materials including smaller organic molecules). In this regard, it is to be understood that the sputtered coating or layer may be structured, e.g. by employing a mask during material deposition. [50] Accordingly, compared to the state of the art, embodiments of the present disclosure beneficially provide for an improved deposition source, an improved deposition apparatus, and an improved method of depositing material on a substrate. [51] In particular, embodiments of the present disclosure are particularly well suited for applying coatings on sensitive substrates or on substrates with pre coated sensitive layers, e.g. comprising polymers or smaller organic molecules. More specifically, embodiments of the present disclosure beneficially provide for thermalization of sputtered particles, such that energy of the particles impinging on the substrate is reduced, e.g. to about ~0.1 eV. Accordingly, embodiments of the present disclosure can be beneficially used for OLED fabrication.

[52] This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any apparatus or system and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

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

Claims

1. A deposition source (100) for depositing material on a substrate (10), comprising

- a sputter source (110), and

- a reflector shield arrangement (120) for reflecting material provided from the sputter source towards the substrate.

2. The deposition source (100) of claim 1, the reflector shield arrangement (120) comprising a first reflector surface (121) facing a sputter side (111) of the sputter source (110).

3. The deposition source (100) of claim 1 or 2, the reflector shield arrangement (120) comprising a second reflector surface (122) facing a lateral side (113) of the sputter source (110).

4. The deposition source (100) of any of claims 1 to 3, the reflector shield arrangement (120) comprising a heating device (130).

5. The deposition source (100) of any of claims 1 to 4, the reflector shield arrangement (120) comprising an aperture (126) for directing material reflected from the reflector shield arrangement (120) towards the substrate (10).

6. The deposition source (100) of any of claims 1 to 5, the reflector shield arrangement (120) comprising at least one shell-like reflector shield (125).

7. The deposition source (100) of claim 6, wherein the at least one shell-like reflector shield (125) has a concave reflector surface (127) facing the sputter source (110).

8. The deposition source (100) of claim 6 or 7, wherein the at least one shell-like reflector shield (125) comprises a first shell-like reflector shield (128) and a second shell-like reflector shield (129) being mirror- symmetrically arranged to each other.

9. The deposition source (100) of any of claims 1 to 8, wherein the sputter source comprises a rotary cathode or a planar cathode.

10. A deposition apparatus (200), comprising:

- a vacuum chamber (210), and

- at least one deposition source for depositing material on a substrate (10) provided in the vacuum chamber, the at least one deposition source comprising a sputter source (110) and a reflector shield arrangement (120) for reflecting material provided from the sputter source towards the substrate, particularly the at least one deposition source is a deposition source (100) according to any of claims 1 to 9.

11. A method of depositing material on a substrate, comprising

- sputtering material from a sputter source towards a reflector shield arrangement,

- reflecting the material from the reflector shield arrangement towards the substrate.

12. The method of claim 11, further comprising heating the reflector shield arrangement.

13. The method of claim 11 or 12, further comprising guiding the material reflected from the reflector shield arrangement (120) through an aperture (126) directed towards the substrate (10).

14. The method of any of claims 11 to 13, further comprising using a deposition source (100) according to any of claims 1 to 9.

15. The method of any of claims 11 to 14, wherein sputtering comprises reactive sputtering, particularly adding nitrogen to a process gas, particularly the process gas comprising argon.

16. A method of manufacturing a device, comprising using at least one of the deposition source according to any of claims 1 to 10 and the method of depositing material of claims 11 to 15.