WO2024022579A1

WO2024022579A1 - Evaporation source, material deposition apparatus, and method of depositing material on a substrate

Info

Publication number: WO2024022579A1
Application number: PCT/EP2022/070947
Authority: WO
Inventors: Stefan Bangert
Original assignee: Applied Materials, Inc.
Priority date: 2022-07-26
Filing date: 2022-07-26
Publication date: 2024-02-01

Abstract

An evaporation source (100) for depositing a material on a substrate (10) is described. The evaporation source (100) includes a crucible (110) for evaporating the material. Further, the evaporation source (100) includes a distributer (120) being in fluid communication with the crucible (110). The distributor (120) includes a temperature control system (121) for controlling a temperature of the distributer (120) at a temperature Td. The temperature Td is equal to or above the melting temperature Tmelting of the material and below the evaporation temperature Tevap of the material (Tmelting ≤ Td < Tevap).

Description

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

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to substrate coating by thermal evaporation in a vacuum chamber. Embodiments of the present disclosure further relate to material deposition of evaporated material onto a substrate. Embodiments also relate to temperature-controlled deposition of material onto a substrate.

BACKGROUND

[0002] Various techniques for deposition on a substrate, for example, chemical vapor deposition (CVD) and physical vapor deposition (PVD) are known. For deposition at high deposition rates, thermal evaporation may be used as a PVD process. For thermal evaporation, a source material is heated up to produce a vapor that may be deposited, for example, on a substrate. Increasing the temperature of the heated source material increases the vapor concentration and can facilitate high deposition rates. The temperature for achieving high deposition rates depends on the source material physical properties, e.g. vapor pressure as a function of temperature, and substrate physical limits, e.g. melting point.

[0003] The deposition of a metal, e.g. lithium, on a flexible substrate, e.g. on a copper substrate, by evaporation may be used for the manufacture of batteries, such as Li-batteries. For example, a lithium layer may be deposited on a thin flexible substrate for producing the anode of a battery. After assembly of the anode layer stack and the cathode layer stack, optionally with an electrolyte and/or separator therebetween, the manufactured layer arrangement may be rolled or otherwise stacked to produce the Li-battery. [0004] Surfaces of the components, e.g. the vacuum chamber walls of the vacuum chamber, may be exposed to the vapor and may be coated. Frequent maintenance to remove condensates is not practical for high volume manufacturing, e.g. web coating on thin foils. Further, expensive coating material may be wasted if components of the vacuum chamber are different from the substrate to be coated.

[0005] Additionally, the material to be deposited is heated up to high temperatures, thereby providing a high heat load to the substrate to be coated. High temperatures, however, may negatively influence the substrate. It is thus beneficial to provide an improved evaporation source, an improved material deposition apparatus, and an improved method of depositing material on a substrate which at least partially overcome the problems in the art.

SUMMARY

[0006] In light of the above, an evaporation source, a material 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.

[0007] According to an aspect of the present disclosure, an evaporation source for depositing a material on a substrate is provided. The evaporation source includes a crucible for evaporating the material. Further, the evaporation source includes a distributer being in fluid communication with the crucible. The distributor has a temperature control system for controlling a temperature of the distributer at a temperature Ta. The temperature Ta is equal to or above the melting temperature T melting of the material. Additionally, the temperature Ta is below the evaporation temperature T_evapof the material.

[0008] According to a further aspect of the present disclosure, a material deposition apparatus for depositing an evaporated material onto a substrate is provided. The material deposition apparatus includes one or more evaporation sources according to any embodiments described in the present disclosure.

[0009] According to a yet further aspect of the present disclosure, a method of depositing material on a substrate is provided. The method includes evaporating the material in a crucible. Additionally, the method includes guiding the evaporated material through a distributer towards the substrate. Further, the method includes controlling a temperature of the distributer at a temperature Ta, wherein Ta is equal to or above the melting temperature T_meiting of the material, and wherein Ta is below the evaporation temperature T_evapof the material (Tmeiting < Ta. < T_evap).

[0010] According to another aspect of the present disclosure, a method of manufacturing a coated flexible substrate is provided. The method includes using at least one of an evaporation source according to any embodiments described herein, a material deposition apparatus according to any embodiments described herein, and a method of depositing material on a substrate according to any embodiments described herein.

[0011] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each 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

[0012] 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 an evaporation source according to embodiments described herein;

FIGS. 2 to 5 show schematic views of an evaporation source according to further embodiments described herein;

FIG. 6A shows a schematic top view of an outlet opening according to embodiments described herein;

FIG. 6B shows a schematic cross-sectional view along line A-A indicated in FIG. 6A;

FIG. 7 shows a schematic view of a material deposition apparatus according to embodiments described herein; and

FIGS. 8 and 9 show block diagrams for illustrating embodiments of a method of depositing material on a substrate as described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0013] 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.

[0014] The embodiments provided herein relate to thin film coating by evaporation, particularly to thin film coating in a vacuum chamber. Typically, the material to be coated is heated up to a material-specific temperature to be evaporated. In general, higher evaporation rates can be provided at higher temperatures. The respective temperature for a specific coating rate depends amongst others e.g. on the material vapor pressure. For high deposition rate processes, the condensation heat load of the material may dominate the heat load on the substrate.

[0015] In evaporation systems, the evaporated material will condensate on surfaces of the system components having a lower temperature than the evaporated material. For thermal coating of a substrate, the substrate includes a lower temperature such that the evaporated material may be coated onto the substrate to form a thin layer on the substrate. During coating, the substrate is subjected to high heat loads due to the temperature of the evaporated material and the radiation from hot surfaces. Further, coating or material deposition based on temperature differences between the material to be deposited and the substrate also provides condensation energy to the substrate. Thus, the condensation energy provided by the deposited material heats up the substrate, particularly at positions where the evaporated material directly hits the substrate. However, in order to reduce thermal stress to the substrate, it is beneficial to provide evaporation sources, deposition apparatuses, and methods with which the heat load on the substrate can be reduced.

[0016] With exemplary reference to FIGS. 1 through 6B, an evaporation source 100 for depositing a material on a substrate 10 according to embodiments of the present disclosure is described. Typically, during material deposition the substrate is transported past the evaporation source 100 in the substrate transport direction T as exemplarily indicated in FIG. 1. [0017] In particular, with exemplary reference to FIG. 1, according to embodiments which can be combined with any other embodiments described herein, the evaporation source 100 includes a crucible 110 for evaporating the material. Typically, the crucible 110 contains the material to be evaporated, as exemplarily indicated with reference number 11 in FIG. 1. Further, the dotted arrows in FIG. 1 indicate the evaporated material 12. Additionally, the evaporation source 100 includes a distributer 120 being in fluid communication with the crucible 110. Typically, the distributor 120 is configured for providing the evaporated material to the substrate 10 and includes a main outlet direction 101 of the distributor 120. The distributor 120 is a temperature-controlled distributor which is configured for controlling a temperature of the distributer 120 at a temperature Ta. The temperature Ta is equal to or above the melting temperature Tmeiting of the material. Further, the temperature Ta is below the evaporation temperature T_evap of the material. Accordingly, the temperature Ta is selected according to the following relation: Tmeiting < Ta < T_evap. In particular, the distributor 120 includes a temperature control system 121 for controlling a temperature of the distributer 120 at a temperature Ta. As exemplarily shown in FIG. 1, the temperature control system 121 may include a plurality of heating elements and/or cooling elements which can be attached to or embedded in walls of the distributor 120.

[0018] Accordingly, beneficially an improved evaporation source for depositing evaporated material on a substrate is provided. In particular, the evaporation source according to embodiments described herein beneficially provides for the possibility of reducing the heat load on the substrate. Further, by providing a distributor which can be maintained at a temperature Ta of Tmeiting < Ta < T_evap, evaporated material condensated on walls of the distributor may flow back into the crucible, such that beneficially condensated material can be recycled. Accordingly, the overall material utilization can be improved. [0019] Before various further embodiments of the present disclosure are described in more detail, some aspects with respect to some terms used herein are explained.

[0020] In the present disclosure, an “evaporation source for depositing a material on a substrate” can be understood as a source configured for depositing material on a substrate by using an evaporation process. In other words, the evaporation source can provide the material to be deposited in an evaporated state to the substrate.

[0021] In the present disclosure, a “crucible for evaporating the material” can be understood as a crucible configured for heating the material to be deposited above the evaporation temperature of the material. In other words, the crucible may contain the material to be deposited and can be evaporated by providing a temperature to the material suitable for evaporating the material. For a better understanding, the material to be deposited is indicated by reference number 11 and the evaporated material 12 is indicated by dotted arrows in FIG. 1. Accordingly, it is to be understood that the crucible typically includes a heater for heating the material contained in the crucible above the evaporation temperature of the material to be deposited.

[0022] For example, the material to be deposited can include, for example, metal, in particular lithium, metal alloys, and other vaporizable materials or the like which have a gaseous phase under given conditions. According to yet further embodiments, additionally or alternatively, the material may include magnesium (Mg), ytterbium (Yb) and lithium fluoride (LiF). Accordingly, the material to be deposited on the substrate can be heated in the crucible to produce vapor at an elevated vapor pressure. The vapor can be transported from the crucible to a distributor as described herein.

[0023] In the present disclosure, a “distributer” can be understood as a device or unit configured for distributing and/or providing evaporated material towards a substrate. Typically, the distributer is in fluid communication with a crucible, particularly via a connection opening 126 as described herein, as exemplarily indicated in FIG. 2. In other words, the crucible can be connected to the distributor via the connection opening, such that the evaporated material may leave the crucible through the connection opening 126 and flow into the distributor.

[0024] In the present disclosure, a “temperature control system for controlling a temperature of the distributer” can be understood as a system configured for controlling the temperature of the distributer, particularly the walls of the of the distributer. In particular, the temperature control system as described herein is configured for controlling the temperature Ta of the distributer, such that at least the interior walls of the distributer between which the evaporated material is guided towards the substrate is controlled at the temperature Ta, wherein Tmeiting < Ta. < Tevap. For example, the temperature control system may include one or more heating elements and/or one or more cooling elements which can be attached to the distributer, particularly to the walls of the distributer. The heating elements may also be referred to as heaters. The cooling elements may also be referred to as coolers. Alternatively, the heating elements and/or cooling elements can be provided inside the walls of the distributer. For example, the heating elements and/or cooling elements can be embedded in the walls of the distributer. In particular, the temperature control system may include a combination of heaters 132 and coolers 132, as exemplarily shown in FIG. 2. For instance, the coolers may be provided at an entrance portion 122in of the one or more outlet channels 122. Typically, the entrance portion 122in is adjacent to the connection opening 126 connecting the crucible 110 and the distributor 120. The heaters may be provided at an outflow portion 122₀ut- Typically, the outflow portion 122in is adjacent to the outlet opening 125. It is to be understood that typically the entrance portion 122in and the outflow portion 122_0ut add up to the complete outlet channels 122. The heaters 132 can be heating wires or other suitable heaters for heating the distributer 120 such that the temperature Ta of the distributer is Tmeiting < Ta < T_evap. As exemplarily shown in FIG. 2, the coolers 132 may be connected to a cooling system 135 for providing the cooling. [0025] Accordingly, the distributer 120 can be a temperature-controlled distributor having one or more outlet channels 122 which may be segmentally heated and/or cooled such that the temperature Ta of the distributer is T_meiting < Td < T_evap. In other words, the one or more outlet channels 122 of the distributer 120 may have one or more segments which include coolers, particularly at the entrance portion 122i_n, and one or more further segments which include heaters, particularly at the outflow portion 122_Out-

[0026] In the present disclosure, the term “melting temperature Tmeiting of the material” can be understood as the temperature at which the material changes from solid to liquid state.

[0027] In the present disclosure, the term “evaporation temperature T_evap of the material” can be understood as the temperature at which the material changes from a liquid to a gaseous state.

[0028] According to embodiments, which can be combined with any other embodiments described herein, the distributor 120 includes one or more outlet channels 122. FIGS. 1 and 2 show exemplary embodiments having one outlet channel. FIG. 3 shows an exemplary embodiment with two outlet channels, particularly a first outlet channel 122 A and a second outlet channel 122B. FIG. 4 shows an exemplary embodiment with three outlet channels, particularly a first outlet channel 122A, a second outlet channel 122B, and a third outlet channel 122C. FIG. 5 shows an exemplary embodiment with a plurality of outlet channels, particularly five outlet channels.

[0029] With exemplary reference to FIG. 2, according to embodiments which can be combined with any other embodiments described herein, the one or more outlet channels 122 have a first end 123 and a second end 124. Typically, the first end 123 is connected to the crucible 110. The second end 124 includes an outlet opening 125. As exemplarily shown in FIG. 2, typically the outlet opening 125 is directed towards the substrate 10 to be coated. Further, as exemplarily shown in FIG. 2, the first end 123 of the one or more outlet channels 122 typically includes a connection opening 126. The connection opening connects the distributor with the crucible, such that evaporated material may exit the crucible 110 via the connection opening 126 and flow into the distributor 120. The evaporated material can exit the distributor 120 at the outlet opening 125. Typically, the outlet opening 125 is larger than the connection opening 126. More specifically, the flow cross-section of the outlet opening 125 can be larger than the flow cross-section of the connection opening 126, which can be beneficial for providing the evaporated material to the substrate in a uniform manner.

[0030] According to embodiments, which can be combined with any other embodiments described herein, the distributor 120 may include a material suitable for contact heating or cooling. For example, the temperature-controlled distributor may be made of a metal material, e.g. of stainless steel, Mo, Ta, W, Invar or other high temperature materials or high temperature metals. For example, also AIN may be provided as a good heat conduction ceramic.

[0031] As exemplarily indicated in FIG. 2, the main outlet direction 101 may extend in the direction from a center of the connection opening 126 to a center of the outlet opening 125. Typically, the main outlet direction 101 is substantially perpendicular to the substrate transport direction T. The term “substantially perpendicular” may be understood as perpendicular within a tolerance t oft <± 15°, particularly t < ± 10°, more particularly t < ± 5°. Accordingly, the main outlet direction 101 can be 90°± t with respect to the substrate transport direction T.

[0032] According to embodiments, which can be combined with any other embodiments described herein, the temperature control system 121 is provided at the one or more outlet channels 122 for controlling the temperature of one or more walls of the one or more outlet channels 122 at the temperature Ta. In particular, the temperature control system 121 may be attached to or embedded in one or more walls of the one or more outlet channels 122

[0033] With exemplary reference to FIGS. 1 through 4, according to embodiments which can be combined with any other embodiments described herein, the one or more outlet channels 122 have an increasing flow cross-section towards the outlet opening 125. In particular, the flow cross-section may continuously increase from the connection opening 126 up to the outlet opening 125. Accordingly, the one or more outlet channels 122 may have a funnel configuration. Typically, the connection opening 126 provides the smallest flow cross-section of the distributor and the outlet opening 125 provides the largest flow cross-section of the distributor.

[0034] With exemplary reference to FIG. 2, according to embodiments which can be combined with any other embodiments described herein, at least two walls, particularly opposing walls 129, of the one or more outlet channels 122 are flat walls. As exemplarily shown in FIG. 2, at least two walls of the one or more outlet channels 122, particularly the opposing walls 129, can be inclined with respect to the main outlet direction 101 of the respective outlet channel of the one or more outlet channels. For example, one or both opposing walls 129 can be inclined with respect to the main outlet direction 101 by an inclination angle a. The inclination angle a can be on < a < on, wherein on can be on = 5°, particularly on = 10°, more particularly on = 15°, and wherein on can be on = 45°, particularly on = 30°, more particularly on = 20°. The inclination angles a of the opposing walls 129 may be equal or different. In other words, the one or more outlet channels 122 can be symmetric or asymmetric with respect to the main outlet direction 101.

[0035] With exemplary reference to FIGS. 3 and 4, according to embodiments which can be combined with any other embodiments described herein, the distributor 120 may include two or more outlet channels 122. For example, the two or more outlet channels 122 may be arranged parallel with respect to each other, as exemplarily shown in FIG. 3. More specifically, a first main outlet direction 101 A of a first outlet channel 122A of the distributor 120 may be substantially parallel with respect to a second main outlet direction 10 IB of a second outlet channel 122B of the distributor 120. The term “substantially parallel” may be understood as parallel within a tolerance t of t < ± 15°, particularly t < ± 10°, more particularly t < ± 5°. [0036] According to embodiments, which can be combined with any other embodiments described herein, two or more outlet channels may be arranged inclined with respect to each other. FIG. 4 shows an example in which three outlet channels of the distributor are inclined with respect to each other. For instance, a second main outlet direction 101B of a second outlet channel 122B can be inclined with respect to a first main outlet direction 101 A of a first outlet channel 122 A by a first inclination angle Pi. For instance, the first inclination angle Pi can be 10° < Pi < 60°, particularly 15° < Pi < 45°; more particularly 20° < i < 30°. Further, a third main outlet direction 101C of a third outlet channel 122B can be inclined with respect to the first main outlet direction 101 A of the first outlet channel 122 A by a second inclination angle P2. For instance, the second inclination angle P2 can be 10° < P2 < 60°, particularly 15° < 02 < 45°; more particularly 20°< P2 < 30°. It is to be understood that the first inclination angle Pi and the second inclination angle P2 can be equal or different. A configuration with inclined outlet channels is advantageous where the substrate 10 to be coated is guided past the evaporation source 100 via a coating drum 211, as exemplarily shown in FIG. 4. Typically, a coating drum is configured to move the substrate 10 on a curved drum surface past the evaporation source 100 in a circumferential direction which may correspond to the substrate transport direction T. For example, the substrate may be a flexible substrate, e.g. a web or foil, as described in more detail with reference to the material deposition apparatus 200 as schematically shown in FIG. 7.

[0037] With exemplary reference to FIG. 5, according to embodiments which can be combined with any other embodiments described herein, the evaporation source 100 further includes a radiation shielding 140 provided around the crucible 110. In other words, the crucible may be enclosed by the radiation shielding. In particular, the radiation shielding is configured for providing a heat shielding. Typically, the radiation shielding includes a plurality of sheets, e.g. of metal. The plurality of sheets can be spaced apart such that a gap is provided between adjacent sheets. More specifically, the plurality of sheets may be arranged in stacks. As schematically shown in FIG. 5, stacks of shielding sheets can be arranged around the crucible 110. [0038] According to embodiments, which can be combined with any other embodiments described herein, the evaporation source 100 further includes a coolable housing 150, as exemplarily shown in FIG. 5. Typically, the coolable housing 150 includes cooling elements which can be attached to or embedded in walls of the housing 150. For instance, the cooling elements may be pipes for a coolant. Typically, the coolable housing 150 is connected to a housing cooling system 155. More specifically, the cooling elements may be connected to the housing cooling system 155 which can be configured for providing a coolant. As exemplarily shown in FIG. 5, the coolable housing 150 may house the crucible 110. Further, the coolable housing 150 may at least partially house the distributer 120. Typically, the temperature control system 121 of the distributor 120 is arranged within the coolable housing 150. The outlet opening 125 is provided outside the coolable housing 150, as exemplarily indicated in FIG. 5

[0039] With exemplary reference to FIGS. 6A and 6B, optional implementations of the outlet opening 125 are described. According to embodiments, which can be combined with any other embodiments described herein, the outlet opening 125 is an elongated opening extending in a cross direction with respect to a substrate transport direction T, as exemplarily shown in FIG. 6A. The term “elongated opening” can be understood as an opening having a length L which is at least two times the width W of the opening. Typically, the width W of the opening is the dimension of the opening in the substrate transport direction T. Accordingly, the length L of the opening is the dimension of the opening perpendicular to the substrate transport direction T. In particular, a ratio of the length L of the outlet opening 125 to the width W of the outlet opening 125 can be LAV > 1.5, particularly L/W > 2, more particularly LAV > 3. Typically, the ratio of the length L of the outlet opening 125 to the width W of the outlet opening 125 is LAV < 4.

[0040] With exemplary reference to FIG. 6A, according to embodiments which can be combined with any other embodiments described herein, the outlet opening 125 widens towards at least one length end of the outlet opening. In particular, at least one length end of the outlet opening 125 may include a widening 128 as exemplarily indicated in FIG. 6 A. According to an example, both length ends of the outlet opening 125 may include a widening 128.

[0041] With exemplary reference to FIG. 6B, according to embodiments which can be combined with any other embodiments described herein, at least one wall of the one or more outlet channels 122 includes a protrusion 127 at the outlet opening 125. Typically, the protrusion 127 extends towards the inside of the one or more outlet channels 122, as exemplarily shown in FIG. 6B. In particular, the protrusion 127 extends towards at least one length end of the outlet opening 125. According to an example, two opposing walls of the one or more outlet channels 122 may include a protrusion 127 as described herein.

[0042] The embodiments as exemplarily described with reference to FIGS. 6 A and 6B are beneficial for improving the uniformity of the flow of evaporated material out of the distributor, such that beneficially the uniformity of the coating on the substrate can be improved.

[0043] With exemplary reference to FIG. 7, a material deposition apparatus 200 for depositing an evaporated material on a substrate 10 according to embodiments of the present disclosure is described.

[0044] According to embodiments, which can be combined with any other embodiments described herein, the material deposition apparatus 200 includes one or more evaporation sources 100 according to any embodiments described herein. Typically, the one or more evaporation sources 100 are provided in a vacuum chamber 201. For example, the material deposition apparatus may include a vacuum pump for providing the vacuum in the vacuum chamber.

[0045] The term “vacuum” as used herein can be understood in the sense of a technical vacuum having a vacuum pressure of less than, for example, 10 mbar. Typically, the pressure in a vacuum chamber as described herein may be between 10'⁴ mbar and about 10'⁸ mbar, more typically between 10'⁴ mbar and 10'⁷ mbar, and even more typically between about 10'⁵ mbar and about 10'⁶ mbar. In some embodiments, the total pressure in the one or more vacuum chambers may range from about 10'⁴ mbar to about 10'⁷ mbar. Accordingly, the vacuum chamber can be a “vacuum deposition chamber”, i.e. a vacuum chamber configured for vacuum deposition.

[0046] According to embodiments, which can be combined with any other embodiments described herein, the material deposition apparatus 200 further includes a substrate transportation device 210 for transporting the substrate along a substrate transportation direction T past the one or more evaporation sources 100. For example, the substrate transportation device can be a coating drum 211.

[0047] The coating drum 211 may be a cylinder extending in a length direction perpendicular to the paper plane of FIG. 7. The coating drum 211 may be rotated around the rotation axis 212. The coating drum may be rotated clockwise or counterclockwise. Generally speaking, the substrate transportation device may change direction during deposition, e.g. when the coating drum is rotated clockwise during deposition, the rotational direction may be changed to counterclockwise and vice versa.

[0048] According to some embodiments, which can be combined with other embodiments described herein, the coating drum may be a gas cushion coating drum. The gas cushion coating drum provides a cooling gas between the surface of the drum and the substrate. For example, the drum and the cooling gas can be cooled to temperatures below room temperature. Heat can be removed from the substrate to allow for higher deposition rates without damaging the thin foil or web on which the material is deposited.

[0049] For a gas cushion roller, a first subgroup of gas outlets, i.e., the open gas outlets, can be provided in a web guiding region of the processing drum. A second subgroup of gas outlets, i.e., closed gas outlets, are provided outside the web guiding region. Since gas is only emitted in the web guiding region where it is needed to form the hover cushion, no or little gas is directly emitted into a region not overlapped by the web, a waste of gas may be reduced and/or a better vacuum may be maintained at lesser strain on the pump system.

[0050] According to some embodiments, which can be combined with other embodiments described herein, additionally or alternatively to the subgroups of gas outlets, the outer surface of the processing drum may be coated with a microporous surface. The microporous surface may allow for a small amount of cooling gas to flow from inside the processing drum to the surface of the processing drum. The cooling gas may form a gas cushion between the processing drum and the web or foil guided over the processing drum for material deposition thereon.

[0051] According to embodiments which can be combined with any other embodiments described herein, the substrate to be coated is a flexible substrate. In the present disclosure, a “flexible substrate” or “thin film substrate” can be understood as a bendable substrate. For instance, the “flexible/thin film substrate” can be a “foil” or a “web”. In the present disclosure the term “flexible substrate”, the term “substrate” and the term “thin film substrate” may be synonymously used. For example, the flexible substrate as described herein may be made of or include materials like PET, HC-PET, PE, PI, PU, TaC, OPP, BOOP, CPP, one or more metals (e.g. copper), paper, combinations thereof, and already coated substrates like Hard Coated PET (e.g. HC-PET, HC-TaC) and the like. In some embodiments, the flexible substrate is a COP substrate provided with an index matched (IM) layer on both sides thereof. According to an example, the flexible substrate may be a metal foil or a flexible metal-coated foil. The substrate may be a transparent or nontransparent substrate. For example, the substrate thickness can be 1 pm or more and 1 mm or less, particularly 500 pm or less, or even 200 pm or less. In particular, the substrate to be coated may have a thickness of 50 pm or less, particularly 20 pm or less, or even 10 pm or less. In some implementations, the substrate is a thin copper foil or a thin aluminum foil having a thickness below 30 pm, e.g. 10 pm or less. The substrate width Ws can be 0.1 m < Ws < 6 m.

[0052] According to embodiments that can be combined with any other embodiment described herein, the material deposition apparatus may include a substrate provision or unwinding roll (not shown in FIG. 7) for providing an unprocessed substrate. The substrate provision or unwinding roll may be moved i.e. rotated such that the substrate may be unrolled from the substrate provision or unwinding roll. Additionally, the material deposition apparatus may include a substrate receiving roll (not shown in FIG. 7) for taking up the processed substrate after deposition of material onto the substrate has taken place. The substrate receiving roll may be moved, i.e. the substrate receiving roll may be rotated for taking up the processed substrate. The unwinding or substrate provision roll and the receiving roll may be each provided in different vacuum chambers compared to the evaporation source or may be provided in the same vacuum chamber as the one or more evaporation sources.

[0053] It is to be understood that, according to embodiments that can be combined with any other embodiment described herein, the material deposition apparatus 200 can be a roll-to-roll material deposition apparatus.

[0054] With exemplary reference to the block diagrams shown in FIGS. 8 and 9, embodiments of a method 300 of depositing material on a substrate 10 according to the present disclosure are described.

[0055] According to embodiments, which can be combined with any other embodiments described herein, the method 300 includes evaporating (represented by block 310 in FIGS. 8 and 9) the material in a crucible. Additionally, the method 300 includes guiding (represented by block 320 in FIGS. 8 and 9) the evaporated material through a distributer 120 towards the substrate 10. Further, the method 300 includes controlling (represented by block 330 in FIGS. 8 and 9) a temperature of the distributer 120 at a temperature Ta. The temperature Ta is equal to or above the melting temperature T_meiting of the material. Additionally, the temperature Ta is below the evaporation temperature T_evap of the material. Accordingly, the temperature Ta is selected according to the following relation: Tmeiting < Ta. < T_evap.

[0056] According to embodiments, which can be combined with any other embodiments described herein, the method 300 further includes recycling (represented by block 340 in FIG. 9) material condensated at walls of the distributer 120. In particular, recycling the condensated material typically includes guiding (represented by block 341 in FIG. 9) the condensated material back into the crucible.

[0057] According to embodiments, which can be combined with any other embodiments described herein, the method 300 further includes cooling (represented by block 350 in FIG. 9) a housing 150 enclosing the crucible 110 and at least partially enclosing the distributer 120.

[0058] It is to be understood that the method 300 of depositing material on a substrate can be carried out by using at least one of an evaporation source 100 and a material deposition apparatus 200 according to any embodiments described herein.

[0059] Further, in view of the embodiments described herein, it is to be understood that a method of manufacturing a coated substrate can be provided. The method of manufacturing the coated substrate includes using at least one of an evaporation source 100 according to any embodiments described herein, a material deposition apparatus 200 according to any embodiments described herein, and a method 300 of depositing material on a substrate according to any embodiments described herein.

[0060] According to yet further embodiments, a method of manufacturing an anode of a battery is provided. The method of manufacturing the anode includes carrying out a method 300 for depositing a material onto a substrate in a vacuum chamber according to any of the embodiments described herein. In particular, the method of manufacturing the anode may include guiding a flexible substrate including an anode layer in a material deposition apparatus 200 according to any the embodiments described herein and depositing a lithium containing material or lithium on the flexible substrate with an evaporation source 100 according to any of the embodiments described herein. [0061] In view of the above, it is to be understood that, compared to the state of the art, embodiments as described herein provide for an improved evaporation source, an improved material deposition apparatus, and an improved method of depositing material on a substrate. In particular, embodiments of the present disclosure beneficially provide for the possibility of reducing heat load on the substrate to be coated. Further, embodiments of the present disclosure beneficially provide for the possibility of recycling condensated coating material. Accordingly, embodiments as described herein beneficially provide for improved material utilization. [0062] 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. An evaporation source (100) for depositing a material on a substrate (10), comprising:

- a crucible (110) for evaporating the material, and

- a distributer (120) being in fluid communication with the crucible (110), the distributor (120) having a temperature control system (121) for controlling a temperature of the distributer (120) at a temperature Ta, wherein Ta is equal to or above the melting temperature T_meiting of the material, and wherein Ta is below the evaporation temperature T_evap of the material (Tmeiting < Ta. < T_evap).

2. The evaporation source (100) of claim 1, wherein the distributor (120) comprises one or more outlet channels (122) having a first end (123) connected to the crucible (110) and a second end (124) having an outlet opening (125).

3. The evaporation source (100) of claim 2, wherein the first end (123) of the one or more outlet channels (122) have a connection opening (126), and wherein the outlet opening (125) is larger than the connection opening (126).

4. The evaporation source (100) of any of claims 2 or 3, wherein the temperature control system (121) is provided at the one or more outlet channels (122) for controlling the temperature of walls of the one or more outlet channels (122) at the temperature Ta.

5. The evaporation source (100) of any of claims 2 to 4, wherein the one or more outlet channels (122) have an increasing flow cross-section towards the outlet opening (125).

6. The evaporation source (100) of any of claims 2 to 5, wherein at least two walls, particularly opposing walls, of the one or more outlet channels (122) are flat walls. The evaporation source (100) of claim 6, wherein the at least two walls are inclined with respect to a main outlet direction (101) of the respective outlet channel of the one or more outlet channels. The evaporation source (100) of any of claims 2 to 7, wherein the outlet opening (125) is an elongated opening extending in a cross direction with respect to a substrate transport direction, particularly wherein the elongated opening widens towards at least one length end of the elongated opening. The evaporation source (100) of any of claims 2 to 8, wherein at least one wall of the one or more outlet channels (122) comprises a protrusion (127) at the outlet opening (125), the protrusion extending towards the inside of the one or more outlet channels. The evaporation source (100) of any of claims 1 to 9, further comprising a radiation shielding (140) provided around the crucible (110). The evaporation source (100) of any of claims 1 to 10, further comprising a coolable housing (150), particularly having a housing cooling system (155), wherein the coolable housing (150) houses the crucible (110) and at least partially the distributer (120). The evaporation source (100) of any of claims 1 to 11, wherein the temperature control system comprises one or more coolers (131) and one or more heaters (132). The evaporation source (100) of claim 12, wherein the one or more coolers (131) are provided at an entrance portion (122in) of the distributor (120), and wherein the one or more heaters (132) are provided at an outflow portion (122_0ut) of the distributor (120). A material deposition apparatus (200) for depositing an evaporated material onto a substrate, the material deposition apparatus comprising one or more evaporation sources (100) according to any of claims 1 to 13. The material deposition apparatus (200) of claim 14, further comprising a substrate transportation device (210), particularly a coating drum (211), for transporting the substrate along a substrate transportation direction past the one or more evaporation sources (100). A method (300) of depositing material on a substrate, comprising evaporating (310) the material in a crucible; guiding (320) the evaporated material through a distributer (120) towards the substrate; and controlling (330) a temperature of the distributer (120) at a temperature Ta, wherein Ta is equal to or above the melting temperature T_meiting of the material, and wherein Ta is below the evaporation temperature T_evapof the material (Tmeiting < Ta. < Tevap)- The method (300) of claim 16, further comprising recycling (340) material condensated at walls of the distributer (120). The method (300) of claim 17, wherein recycling (340) the condensated material comprises guiding (341) the condensated material back into the crucible. The method (300) of any of claims 17 to 18, further comprising cooling (350) a housing (150) enclosing the crucible (110) and at least partially enclosing the distributer (120). A method of manufacturing a coated substrate, comprising using at least one of an evaporation source (100) according to any of claims 1 to 13, a material deposition apparatus (200) according to claim 14 or 15, and a method (300) of depositing material on a substrate according to any of claims 16 to 19.