Vapor deposition apparatus and method for coating a substrate in a vacuum chamber - Patents.com

Abstract

A crucible for flash evaporation of a liquid material is described, the crucible including one or more sidewalls and a reservoir portion below the one or more sidewalls, the reservoir portion having a first cross-section of a first size and a second cross-section above the first cross-section of a second size larger than the first size.

Description

[Technical field]

[0001]

[0001] Embodiments of the present disclosure relate to coating a substrate by thermal evaporation in a vacuum chamber. Embodiments of the present disclosure further relate to coating by flash evaporation. Embodiments also relate to coating of alkali metals, such as lithium, and / or alkaline earth metals. In particular, embodiments relate to a crucible for flash evaporation of a liquid material, a vapor deposition apparatus, a method for coating a substrate in a vacuum chamber, and a method for manufacturing an anode for a battery. [Background technology]

[0002]

[0002] Various techniques are known for deposition onto a substrate, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). For deposition at high deposition rates, thermal evaporation can be used as a PVD process. For thermal evaporation, a source material is heated to generate a vapor that can be deposited onto the substrate. Increasing the temperature of the heated source material can increase the vapor concentration and promote a high deposition rate. The temperature to achieve a high deposition rate depends on the physical properties of the source material, such as the vapor pressure as a function of temperature, and the physical limitations of the substrate, such as the melting point.

[0003]

[0003] For example, a source material to be deposited on a substrate can be heated in a crucible to generate a vapor at high vapor pressure. The vapor can be transported from the crucible to a coating space in a heated manifold. From the heated manifold, the source material vapor can be distributed onto the substrate in the coating space, for example, a vacuum chamber.

[0004]

[0004] Modern thin-film lithium batteries may include a lithium layer, which is formed, for example, by depositing lithium in the vapor state onto a substrate. Due to the high reactivity of lithium, several measures must be taken to operate and maintain such a deposition system.

[0005]

[0005] For alkali and / or alkaline earth metals, the method has serious challenges in managing the high reactivity of the materials while scaling up to mass production, so some configurations are not very suitable for mass production and low-cost manufacturing. This brings challenges in producing uniformly deposited pure lithium. Highly reactive materials, especially lithium, can be easily oxidized in reactions with the surrounding environment, e.g., gases, materials, etc. Lithium is of particular interest because it is suitable for the production of higher energy density batteries and accumulators, i.e., primary and secondary batteries.

[0006]

[0006] A typical deposition system for lithium and other alkali or alkaline earth metals may utilize a sputter source or a conventional evaporation source, respectively, and a method of operating the evaporation source. The sputtering method of lithium is particularly challenging in terms of cost and manufacturability, given the reactivity of lithium. The high reactivity first affects the manufacturing of the target, which is an essential component of sputtering, and then affects the handling of the resulting target. The relatively low melting point of lithium, 183°C, can also limit the deposition rate, as this melting point limits the area more suitable for high volume and low cost manufacturing to the high power density sputtering area. In other words, the low melting point of lithium limits the maximum deposition rate that can be achieved by limiting the maximum power that can be applied.

[0007]

[0007] It would therefore be advantageous to have an improved crucible, an improved vapor deposition apparatus, and an improved method for manufacturing electrodes for thin film batteries. Summary of the Invention

[0008]

[0008] In view of the above, there is provided a vapor deposition apparatus and a method for coating a substrate in a vacuum chamber according to the independent claims. Further aspects, advantages and features of the present disclosure will become apparent from the description, and from the accompanying drawings.

[0009] According to one embodiment, there is provided a crucible for flash evaporation of a liquid material, the crucible including one or more side walls and a reservoir portion below the one or more side walls, the reservoir portion having a first cross section of a first size and a second cross section above the first cross section of a second size larger than the first size.

[0010] According to one embodiment, a vapor deposition apparatus is provided, the vapor deposition apparatus including a crucible according to any of the embodiments of the present disclosure.

[0011] According to one embodiment, there is provided a vapor deposition apparatus configured to evaporate an alkali metal and / or alkaline earth metal, in particular lithium, comprising a flow meter with a measurement unit external to a conduit for a liquid material.

[0012] According to one embodiment, there is provided a method of coating a substrate in a vacuum chamber, the method including directing a liquid material to a crucible for flash evaporation, in particular a crucible according to any of the embodiments of the present disclosure, flash evaporating the liquid material in the crucible, and measuring a flow rate of the liquid material to control a deposition rate of the material on the substrate.

[0013] According to one embodiment, there is provided a method for manufacturing a battery anode, the method comprising: coating a substrate in a vacuum chamber according to any of the embodiments described herein.

[0014] According to one embodiment, there is provided a method of manufacturing a battery anode, the method comprising directing a web including or consisting of an anode layer in a vapor deposition apparatus according to any of the embodiments of the present disclosure, and depositing a lithium-containing material or lithium on the web using the vapor deposition apparatus.

[0015]

[0015] In order that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above may be had by reference to the embodiments. The accompanying drawings relate to the embodiments of the present disclosure and are described below. [Brief description of the drawings]

[0016] [Figure 1] 1 shows a schematic diagram of a vapor deposition apparatus having a flow meter according to an embodiment of the present disclosure and a flow valve according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 shows a schematic diagram of a crucible for flash evaporation according to an embodiment of the present disclosure. [Diagram 3] 1A-C show schematic cross-sectional views of a crucible providing a self-adjusting fill height according to embodiments described herein. [Figure 4] FIG. 1 shows a schematic diagram of a vapor deposition apparatus having an evaporator according to an embodiment of the present disclosure. [Diagram 5] FIG. 1 shows a schematic diagram of an evaporator according to an embodiment of the present disclosure. [Figure 6] 1 shows a flow chart illustrating a method of coating a substrate in a vacuum chamber according to embodiments described herein. [Figure 7] 1 shows a flow chart illustrating a method of manufacturing a battery anode according to embodiments described herein. [Figure 8] FIG. 1 shows a schematic diagram of an evaporator according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017]

[0016] Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are illustrated in the figures. In the following description of the drawings, like reference numerals represent like components. Only the differences with respect to the individual embodiments will be described. Each example is provided as an explanation of the disclosure, and is not intended to limit the disclosure. Moreover, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield still further embodiments. The description is intended to include such modifications and variations.

[0018]

[0017] In the following description of the drawings, the same reference numbers refer to the same or similar components. Generally, only differences related to individual embodiments are described. Unless otherwise specified, the description of a part or aspect in one embodiment also applies to the corresponding part or aspect in another embodiment.

[0019]

[0018] The present disclosure relates to an embodiment of a vapor deposition apparatus for flash evaporation, i.e. a vapor deposition apparatus having a crucible for flash evaporation. In particular, the crucible for flash evaporation can be self-adjusting to the filling height of the crucible at a given amount of evaporated material. Additionally or alternatively, a flow meter outside the conduit for the liquid material and / or a valve with an adjustment element outside the conduit for the liquid material can be provided.

[0020]

[0019] In the following, one or more evaporation concepts are described for lithium as the material to be evaporated. According to some embodiments that can be combined with other embodiments described herein, the evaporation concept can also be applied to other materials. In particular, the evaporation concept can also be applied to highly reactive materials, such as alkali metals or alkaline earth metals. Furthermore, the evaporation concept can be advantageously used for very high deposition rates, resulting in layer thicknesses of several microns or more on a roll-to-roll coater.

[0021]

[0020] In the evaporation concept according to the embodiments of the present disclosure, only a small amount of liquid Li is present in the crucible, which is evaporated in a very short time (flash evaporator). The evaporated material is continuously fed into the crucible, for example by a dosing pump. According to the embodiments of the present disclosure, in the case of flash evaporation, the evaporation rate is controlled by the amount of material fed into the crucible, for example by the amount of material provided by the dosing pump and / or the flow rate of liquid material into the crucible. The evaporation rate is not controlled by the temperature of the crucible.

[0022]

[0021] Flash evaporation can be beneficial because it essentially allows for continuous operation for a nearly infinite time frame. Additionally or alternatively, deposition rate control can be more easily measured compared to crucible temperature control combined with deposition rate measurement, for example, using a quartz crystal microbalance (QCM), which must be frequently replaced or regenerated. This is especially true for embodiments of the present disclosure that provide a vapor deposition apparatus with near perfect material utilization. The deposition rate can essentially correspond to the rate at which liquid material is fed into the crucible.

[0023] According to some embodiments, evaporation can be provided by flash evaporation, in particular at a temperature of 600° C. or higher. For example, the temperature can be 800° C. or higher. Prior to flash evaporation, the liquefied material is maintained at a temperature between 190° C. and 300° C. higher than the melting point of the material to be deposited, for example between 373° C. and 483° C. for metallic lithium.

[0024] According to some embodiments, which can be combined with other embodiments described herein, the crucible for flash evaporation contains only a small amount of material to be evaporated in the evaporation area. For example, the evaporation area is 200 cm 3 It may have a volume and / or an amount of material (e.g., lithium) of less than 10 cm 3 It may have the following volumes:

[0025]

[0024] The liquid material to be evaporated can be dispensed by a dosing pump into an evaporation crucible where the material (e.g., lithium) evaporates. The dosing pump can define the amount of liquid material provided to the crucible for flash evaporation. The evaporation rate is defined by the dosing pump or the flow rate of the liquid material, not the temperature of the crucible.

[0026] According to some embodiments, a method or device for evaporation of a material, particularly an alkali metal or an alkaline earth metal, is provided. A first chamber configured to liquefy the material is provided. The first chamber comprises a gas inlet configured for the inlet of a gas in the first chamber, and in particular can provide pressure control of the gas. For example, the gas can be an inert gas, such as argon. An evaporation zone configured to flash evaporate the liquefied material is provided in the second chamber. A line or conduit is provided providing a fluid connection between the first chamber and the evaporation zone. The flow rate of the liquid material in the line or conduit defines the deposition rate. The flow rate can be adjusted according to embodiments of the present disclosure. According to some embodiments, which can be combined with other embodiments described herein, the evaporation zone can be provided in a crucible. The crucible can be included in an evaporator, in particular an evaporator having a plurality of nozzles, such as a one-dimensional array of nozzles or a two-dimensional array of nozzles.

[0027]

[0026] According to some embodiments, which can be combined with other embodiments described herein, the evaporator can include a crucible and an enclosure in fluid communication with the crucible. The enclosure, i.e., the distribution enclosure, can be a steam distribution pipe or a steam distribution showerhead. The steam can leave the enclosure through a number of nozzles in or on the wall of the enclosure. In particular, the pressure in the enclosure is at least one or of magnitude higher than the pressure in a second chamber, e.g., a vacuum chamber in which the evaporator is at least partially located.

[0028]

[0027] Figure 1 shows a vapor deposition apparatus 100. The vapor deposition apparatus includes a first compartment, indicated by dashed line 102. The first compartment is configured to maintain a temperature higher than the melting temperature of the material to be evaporated. For example, for lithium, the first temperature of the first compartment can be 190° or more, for example 220° or more. Atmospheric conditions are provided in the first compartment. According to some embodiments, which can be combined with other embodiments described herein, the atmospheric conditions can be provided with a relative humidity of 2% or less, for example 1% or less, or even 0.5% or less. Thus, the first compartment can include a dehumidifier, in particular a dehumidifier configured to provide the above-mentioned relative humidity. Reducing the humidity in the first compartment can be particularly useful for evaporating highly reactive materials, for example alkali metals or alkaline earth metals, such as lithium.

[0029]

[0028] A tank 120 is provided to liquefy the material to be evaporated. A gas conduit 122 is in fluid communication with the tank 120. A gas, such as an inert gas, can be disposed in the tank 120. A pressure control can be provided for the gas conduit 122 to generate an overpressure in the tank. The liquid material to be deposited in the evaporation zone is guided through a conduit 124. The overpressure in the tank 120 moves the liquid material through the line or conduit 124. According to some embodiments, which can be combined with other embodiments described herein, the pressure in the tank 120 can be controlled to be constant during evaporation. The pressure in the tank 120 may not be utilized to regulate the deposition rate.

[0030]

[0029] The flow meter 130 measures the flow rate of the liquid material in the line or conduit 124. The flow meter 130 is connected to a controller 132. For example, the controller can be a PID controller. According to some embodiments, which can be combined with other embodiments described herein, the controller is configured for closed-loop control. The flow rate measured by the flow meter 130 is provided as an input for the controller 132. The controller 132 adjusts the flow valve 140 to adjust the flow rate in the line or conduit 124. The liquid material is delivered at a predetermined flow rate into the process chamber 160. The process chamber 160 includes an evaporation zone configured for flash evaporation. The predetermined flow rate of the liquid material in the conduit 124 defines a deposition rate of the process chamber.

[0031] According to some embodiments, which may be combined with other embodiments described herein, the process chamber 160 may be provided under vacuum conditions. At least an evaporator in the process chamber may additionally be provided at a high temperature, for example, 500° C. or higher (such as 600° C. to 800° C.). The area including the process chamber 160 is indicated by dashed line 106 in FIG. 1. The processing chamber 160 may be a vacuum chamber. According to some embodiments, the area (see dashed line 106) may be provided as a vacuum chamber, and the processing chamber 160 may be provided within the vacuum chamber.

[0032] According to an embodiment of the present disclosure, the flow meter 130 can be located outside the conduit for the liquid material, and / or the flow valve 140 can have an adjustment element outside the conduit for the liquid material. Measuring the flow from outside the conduit and adjusting the flow rate from outside the conduit reduces the probability of the liquid material sticking to components inside the conduit, which may result in clogging of the conduit. Undesirable clogging of the conduit is a very serious situation, especially for highly reactive materials such as lithium.

[0033]

[0032] According to an embodiment of the present disclosure, a flow valve for a vapor deposition apparatus is provided. The flow valve can be a membrane flow valve. The conduit for the membrane flow valve is not provided with moving elements. Alternatively, a motor-driven flow valve can be used. The flow valve can provide a constant flow of liquid material, for example liquid lithium.

[0034]

[0033] The flow valve 140 includes a membrane. The membrane may be configured to adjust the cross-sectional area of ​​the conduit 124 and / or may form part of the conduit 124. A gas, for example an inert gas such as argon, is provided in the conduit 141. A control valve 142 adjusts the pressure of the gas in the conduit 143 between the control valve and the flow valve 140. The pressure of the gas in the conduit 143 actuates a movable membrane of the flow valve 140. An increase in pressure in the conduit 143 may reduce the cross-sectional area in the flow valve 140, i.e., the cross-sectional area of ​​the conduit 124.

[0035]

[0034] The flow restricting element 144 is in fluid communication with the conduit 143. The conduit 145 can be in fluid communication with the flow restricting element 144 and the pump. The flow restricting element 144 releases the pressure in the conduit 143. The gas passing through the flow restricting element 144 can be pumped by the vacuum pump 146. For example, the vacuum pump 146 can be a vacuum pump utilized to at least partially evacuate a vacuum chamber for a process region. The flow restricting element 144 causes leakage, particularly constant leakage, in the conduit 143. Thus, the pressure in the conduit 143 can be reduced. The reduced pressure increases the cross-sectional area in the flow valve 140.

[0036] According to some embodiments, which may be combined with other embodiments described herein, the first compartment 102 may be provided with insulation at the interface with the first compartment or at least partially around the first compartment. Thus, the temperature in the first compartment may be above the melting temperature of the material to be evaporated, in particular always above the melting temperature. One or more components in the compartment, in particular the components in contact with the material to be evaporated, may also be provided above the melting temperature. Blocking of the material (e.g. lithium) may be avoided. For example, a line such as the conduit 122 or the conduit 143 may be provided with a material that is a poor heat conductor, for example stainless steel. For example, the conduit 143 may have an insulator at the interface with the first compartment 102.

[0037]

[0036] The flow meter 130, the controller 132, the control valve 142, the flow valve 140, and the flow restricting element 144 may provide a closed loop control circuit.

[0038]

[0037] According to some embodiments, which may be combined with other embodiments described herein, the flow meter 130 may be external to the conduit, i.e. measurements are provided from outside the conduit through which the material to be evaporated flows. According to some embodiments, the flow meter may be a Coriolis flow meter, such as a Coriolis mass flow meter. Coriolis flow meters are based on the Coriolis force. A tube or a portion of the conduit is energized by vibration. The excitation causes the tube or portion of the conduit to vibrate. The mass of the medium flowing through the tube may change the vibration of the tube, in particular introducing a phase shift in the vibration. For example, the tube may be twisted by the Coriolis force. The resulting change in the vibration, such as the phase shift, may be measured. The measurement results in an output that correlates with the mass flow rate in the tube or conduit. For example, the output may be proportional to the flow. Thus, the flow rate in the conduit may be measured while reducing or avoiding the risk of clogging the conduit.

[0039]

[0038] Figure 2 shows a part of the evaporator 260. The conduit 124 delivers the liquid material to be evaporated into the crucible 280. According to some embodiments, which can be combined with other embodiments described herein, the material can be lithium or any other material described herein. The material is evaporated in the crucible 280. The crucible is in fluid communication with the enclosure 262. One wall 263 of the enclosure 262 is shown in Figure 2. A further wall of the enclosure 262, for example the wall opposite the wall 263, can include a number of nozzles for directing the material towards the substrate. To measure the temperature of the crucible, an electric line 282 of a thermocouple is provided. The crucible 280 can be provided with an electric heater for heating the crucible. The crucible can be electrically heated or connected to another electric heater. For example, the crucible can be connected to a graphite heater. For example, the graphite heater can at least partially surround the crucible. According to some embodiments, evaporation can be provided by flash evaporation. The temperature of the crucible can be 600° C. or higher. For example, the temperature can be 800° C. or higher. A heat shield 284 can be provided at least partially around the crucible to reduce heat loss in the crucible, reduce heat radiation towards other components, and / or increase the temperature stability of the crucible. As mentioned above, the temperature can be stabilized since it is not utilized to control the deposition rate.

[0040]

[0039] According to an embodiment of the present disclosure, the crucible can be shaped to self-regulate the flash evaporation. Figures 3A to 3C depict different cross sections of differently shaped crucibles.

[0041] According to embodiments described herein, the crucible 280 includes one or more side walls 310. For example, the side walls 310 may form a cylinder. According to some embodiments, which may be combined with other embodiments described herein, the cylinder may be open at the top to allow for fluid communication with the enclosure 262. The crucible 280 further includes a reservoir portion 320 below the one or more side walls 310. The reservoir portion 320 is closed at a bottom 321 of the reservoir portion.

[0042] According to some embodiments, which can be combined with other embodiments described herein, the reservoir portion can have a semicircular cross section (see FIG. 3A), a cross section corresponding to a portion of an ellipse (see FIG. 3C), or a tapered cross section (see FIG. 3B). For example, the tapered cross section can be a cone or a truncated cone, as shown in FIG. 3B.

[0043] 3A-3B, in top view, the reservoir portion has a lower cross section 380 that is smaller than an upper cross section 382. As shown in FIG. 2, the crucible and reservoir portion can be filled with liquid material from the top of the reservoir portion through conduit 124. Depending on the amount of liquid material inserted into the crucible, a fill height of the liquid material in the reservoir portion is generated.

[0044] According to an embodiment of the present disclosure, the fill height and / or the rate of flash evaporation is self-adjusting, particularly based on the flow rate of liquid material into the crucible. If the flow rate of liquid material in the crucible is relatively low, the fill height is low, e.g., close to the bottom cross section 380. Thus, the liquid material is in contact with a relatively small surface area of ​​the crucible. There is an equilibrium between a given flow rate of liquid material and the resulting fill height.

[0045]

[0044] For a first predetermined flow rate, a higher (overly high) fill height in the reservoir portion results in a higher evaporation rate due to a larger cross section closer to the upper cross section 382. More material is evaporated than is filled into the crucible by flash evaporation. Thus, the fill height decreases until equilibrium occurs. Similarly, if a second predetermined flow rate is provided with a lower (overly low) fill height in the reservoir portion, a smaller fill height, i.e. smaller and closer to the lower lower cross section 380, results in an increase in the fill height due to a smaller evaporation surface until equilibrium is provided. In light of the above, the crucible is self-adjusting to various flow rates of liquid material. Thus, if the flow rate of liquid material fluctuates, the crucible cannot be overfilled. The fill height is self-adjusting in case of fluctuation. A corresponding surface area is provided in the reservoir portion of the crucible with varying sizes in the cross section along the fill height, and the fill height in the crucible provides a surface area for evaporation and equilibrium with the flow rate of liquid material inserted into the crucible.

[0046]

[0045] According to some embodiments, which can be combined with other embodiments described herein, the temperature of the crucible can be provided to have a low fill height, which at this temperature is self-adjusting when the flow rate of the liquid material varies. The deposition rate depends on the flow rate of the liquid material.

[0047] 3A-3B show a crucible 280 having one or more side walls 310 and a reservoir portion 320, the cross section of the crucible, i.e. the cross section in the top view of the inner wall of the crucible, being circular. According to yet another variant, which can be combined with other embodiments described herein, the cross section of the crucible in the top view, i.e. the inner wall of the crucible, can also have another shape, for example rectangular or polygonal. A polygonal top cross section, in particular a tapered cross section side view as shown in FIG. 3B, can be provided.

[0048]

[0047] According to some embodiments, which can be combined with other embodiments described herein, the shape of the evaporation surface of the crucible is provided such that the size of the evaporation surface increases with the liquid content, i.e., the fill height. The size of the evaporation surface can increase directly with the liquid content. Different flow rates can therefore be evaporated at a constant or nearly constant crucible temperature. For a given evaporation rate, the fill height, i.e., the size of the liquid pool in the crucible, is a function of the evaporation temperature, i.e., the temperature of the crucible. The fill height or the size of the pool of liquid material can be adjusted by the crucible temperature. The crucible is provided at an elevated temperature for flash evaporation as described herein. The temperature of the crucible does not affect the evaporation rate or the deposition rate, respectively, because the equilibrium fill height is established as described above.

[0049]

[0048] Figure 8 shows an evaporator according to yet another embodiment. The embodiment described with respect to Figure 8 may also be combined with other embodiments of the present disclosure. A crucible 280 is provided in fluid communication with an enclosure 262, i.e. a distribution enclosure. Vapor can leave the enclosure through a nozzle 462. A liquid material, for example liquid lithium, is filled from the bottom of the crucible. The liquid material can be provided by a conduit 124. The crucible can be heated by an electric heater 884. For example, the crucible can be connected to a graphite heater. As shown in Figure 8, the surface between the electric heater and the crucible can be enlarged by protrusions and / or recesses. Filling the crucible from the bottom may have the advantage that splashing of the liquid material in the pool of material to be flash evaporated is avoided.

[0050]

[0049] Figure 4 shows a schematic diagram of a further vapor deposition apparatus 400 having one or more evaporators according to an embodiment of the present disclosure. The apparatus provides a process direction of a web 410 or foil from below a processing drum 420. The web 410 is guided onto the processing drum 420 by rollers 422. The processing drum rotates as shown by the arrow, moving the web through the processing area of ​​the evaporator 260. Figure 4 shows three evaporators 260.

[0051] According to some embodiments, the one or more evaporators 260 can include a crucible 280 that evaporates liquid material that is directed through a conduit 124 within the crucible. The vapor is dispersed within the enclosure 262. The vapor is directed through a nozzle 462 toward the web that is provided on the processing drum 420.

[0052] According to some embodiments, which can be combined with other embodiments described herein, a heat shield 464 can be provided. The evaporator and processing drum are at least partially located in a vacuum chamber (not shown in FIG. 4). The processing region of the evaporator 260 is in the vacuum chamber. The enclosure 262 acting as a vapor distribution enclosure can have a vapor pressure that is at least one magnitude higher compared to the pressure inside the enclosure, i.e., the pressure in the vacuum chamber or the processing region, respectively.

[0053]

[0052] The heatable shield 464 is heatable, and when the heatable shield is heated to an operating temperature (e.g., 500°C or more, e.g., an operating temperature of 500°C to 600°C in some embodiments), vapor condensation on the heatable shield 464 can be reduced or prevented. Preventing vapor condensation on the heatable shield is beneficial because it can reduce cleaning efforts. Furthermore, a coating on the heatable shield 464 can change the size of the coating window provided by the heatable shield. In particular, when a gap of only a few millimeters, e.g., in the range of about 1 mm or less, is provided between the heatable shield 464 and the substrate support, a coating on the heatable shield will result in a change in the gap size and thus an undesirable change in the edge shape of the coating layer deposited on the substrate. Furthermore, the utilization of the source material can be improved when the source material does not accumulate on the heatable shield. Specifically, essentially all of the source material propagating inside the vapor propagation volume can be used to coat the substrate surface when the heatable shield is heated to an operating temperature that may exceed the vapor condensation temperature.

[0054]

[0053] As used herein, "vapor condensation temperature" may be understood as a threshold temperature of the heatable shield at which vapor no longer condenses on the heatable shield. The operating temperature of the heatable shield 464 may be the vapor condensation temperature or (slightly) higher. For example, the operating temperature of the heatable shield may be between 5°C and 50°C higher than the vapor condensation temperature to avoid excessive heat radiation towards the substrate support. It should be noted that the vapor condensation temperature may depend on the vapor pressure. Since the vapor pressure downstream of the nozzles in the vapor propagation space is lower than the source pressure inside the crucible and / or inside the distributor of the vapor source, the vapor inside the vapor source may already condense at a lower temperature than the vapor inside the vapor propagation 20. As used herein, "vapor condensation temperature" refers to the temperature of the heatable shield downstream of the nozzles in the vapor propagation space 20 that avoids vapor condensation on the heatable shield. As used herein, "evaporation temperature" refers to the temperature inside the vapor source upstream of the nozzles at which the source material evaporates. The evaporation temperature in the vapor source is typically higher than the vapor condensation temperature inside the vapor propagation space. For example, the evaporation temperature inside the vapor source can be set to a temperature above 600° C., e.g., 750° C.-850° C., while the vapor condensation temperature downstream of the nozzles can be less than 600° C., e.g., 500° C.-550° C., when lithium is evaporated. In the embodiments described herein, the temperature inside the vapor source is 600° C. or higher, and the operating temperature of the heatable shield can be set to less than 600° C., e.g., 500° C.-550° C., during vapor deposition.

[0055]

[0054] The vapor impinging on the heatable shield, provided for example at an operating temperature of 500°C to 550°C, is immediately re-evaporated or reflected from the heatable shield surface, so that each vapor molecule ends up on the substrate surface, rather than on the heatable shield surface. Material accumulation on the heatable shield can be reduced or prevented, and cleaning efforts can be reduced.

[0056]

[0055] The "heatable shield" may also be referred to herein as a "temperature-controlled shield" because the temperature of the heatable shield may be set to a predetermined operating temperature during vapor deposition to reduce or prevent vapor condensation on the heatable shield. In particular, the temperature of the heatable shield may be controlled to be maintained within a predetermined range. A controller and a respective heating device controlled by the controller may be provided to control the temperature of the heatable shield during vapor deposition.

[0057]

[0056] The embodiments of the present disclosure relate to vapor apparatuses, especially for high deposition rates. For example, for the manufacture of thin-film batteries, deposition rates of a few micrometers, e.g., 10 μm or more, are beneficial for cost-effective mass production. Commonly used evaporators can provide material utilization rates of about 60% to 80%. At high deposition rates, accumulation of 20% or 40% of the evaporated material on the components of the vapor deposition apparatus, e.g., by shielding, will result in a fast growth of a material layer on the components. Maintenance cycles for removing the accumulated material on the components of the vapor deposition apparatus will be very short.

[0058]

[0057] Thus, the evaporator or vapor deposition apparatus according to the embodiments of the present disclosure provides a material utilization of at least 90%, particularly 95% or more. The material is flash evaporated. No accumulation of material occurs in the crucible 280. The enclosure 262 and the nozzle 462 are also provided at an elevated temperature to avoid or reduce material accumulation. The heated shield 464 is also provided at a temperature above the condensation temperature. Thus, most or all of the material provided in the evaporator 260 is deposited on the substrate, e.g., the web 410.

[0059] According to an embodiment of the present disclosure, an apparatus and method for coating by evaporation in a vacuum chamber is provided. To deposit a substrate with a source material by evaporation, the source material can be heated above the evaporation or sublimation temperature of the source material. An embodiment of the present disclosure provides for reduced condensation on surfaces, for example, surfaces other than the substrate, which may have a lower temperature. Such a surface can be, for example, the chamber wall 501 of the vacuum chamber shown in FIG. 5.

[0060]

[0059] Figure 5 shows a schematic diagram of a further vapor deposition apparatus having one or more frames or heat shields according to an embodiment of the present disclosure. The embodiment described with respect to Figure 5 may be combined with other aspects, details, embodiments, and features described in the present disclosure. The material to be deposited, i.e. the source material, is evaporated in the crucible by heating the material. The material may include, for example, metals, in particular lithium, metal alloys, and other vaporizable materials having a gas phase under given conditions. According to a further embodiment, additionally or alternatively, the material may include magnesium (Mg), ytterbium (YB), and lithium fluoride (LiF). The evaporated material generated in the crucible may enter the enclosure 262, for example, a distributor along the direction represented by the arrow 581. The distributor may include, for example, channels or tubes providing a transport system for distributing the evaporated material along the width and / or length of the deposition apparatus. The distributor may have a "showerhead reactor" design.

[0061]

[0060] As exemplarily shown, the evaporation source material can be guided in the distributor along the directions 583 and 585. The directions 583 and 585 can be essentially parallel to the substrate surface 110 or parallel to the wall 263 of the enclosure 262. In the coating drum of a roll-to-roll coater, the directions 583 and 585 can also be curved according to the tangent of the coating drum at the shortest distance between the source and the drum. The evaporated material is discharged from the evaporator 260 into the interior of the vacuum chamber by the nozzle 462. The nozzle 462 can be disposed in the opening 562 of the heat shield 570. The evaporated material 585 discharged by the nozzle is deposited on the substrate surface 110 of the substrate, for example, the web 410, to form a coating on the substrate. The evaporator provides a processing region 560.

[0062]

[0061] The heat shield 570 reduces radiant heat from the evaporator towards the substrate. According to an embodiment of the present disclosure, the heat shield 570 includes an opening 562. According to some embodiments, which can be combined with other embodiments described herein, the nozzle 462 of the distributor can extend through the opening of the heat shield 570.

[0063]

[0062] According to embodiments that can be combined with other embodiments described herein, the evaporated material can comprise or consist of lithium, Yb, or LiF. According to embodiments that can be combined with other embodiments described herein, the temperature of the evaporator and / or nozzle can be at least 600°C, or in particular 600°C to 1000°C, or more specifically between 600°C and 800°C. According to embodiments that can be combined with other embodiments described herein, the temperature of the heated shield can be between 450°C and 600°C, in particular about 550°C with a deviation of ±10°C or less.

[0064]

[0063] According to an embodiment that can be combined with other embodiments described in this specification, the temperature of the heated shield is at least 100°C lower than the temperature of the evaporator, particularly up to 300°C lower, and more particularly at least 100°C and up to 300°C lower.

[0065]

[0064] Furthermore, by heating the heat shield, material deposited on the surface of the heat shield, for example by stray coating, can also be re-evaporated. The stray coating material on the heat shield can be advantageously removed by re-evaporation as described herein. Furthermore, by re-evaporating material from the heat shield, the coating on the substrate can also be made more uniform, increasing material utilization.

[0066]

[0065] The heated shield can be a temperature-controlled shield. The temperature-controlled shield can improve the deposition process inside the vacuum chamber. The temperature of the temperature-controlled shield can be high enough to reduce the condensation of evaporated material on the chamber walls. Furthermore, the temperature of the temperature-controlled or heated shield can also be low enough to keep the heat load on the substrate low.

[0067]

[0066] Additionally, stray coating material on the heated shield can be re-evaporated and deposited on the substrate. Furthermore, by re-evaporating material from the heat shield, the coating on the substrate can also be made more uniform, improving material utilization. By reducing stray coating on the chamber walls with the heated shield, the vacuum deposition chamber can be operated at a higher throughput of evaporated material, further increasing the production rate of coated substrates.

[0068]

[0067] The crucible, vapor deposition apparatus, method of coating a substrate in a vacuum chamber, and the unknown method of manufacturing batteries may be particularly useful for depositing lithium, which may be deposited on a thin web or foil to improve mass production of thin-film batteries.

[0069]

[0068] Lithium can be deposited, for example, on a thin copper foil to produce an anode of a battery. Furthermore, a layer comprising graphite and at least one of silicon and silicon oxide can be provided on a thin web or foil. The web or foil can further comprise a conductive layer or can consist of a conductive layer that serves as a contact surface of the anode. The lithium deposited on the layer on the web can provide prelithiation of the layer comprising graphite and at least one of silicon and silicon oxide.

[0070]

[0069] For mass production, a high deposition rate is advantageous. However, the web or foil, especially in roll-to-roll deposition processes, is very thin. Heat transfer on the substrate is dominated by the condensation energy of the evaporated material. Furthermore, heat removal from the substrate in vacuum processes is dominated by thermal conduction. Therefore, the vapor deposition apparatus according to the embodiments of the present disclosure advantageously includes a coating drum configured to effectively remove heat from the substrate.

[0071]

[0070] According to some embodiments, which can be combined with other embodiments described herein, the coating drum can 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 a temperature lower than room temperature. Heat can be removed from the substrate to enable higher deposition rates without damaging the thin foil or web on which the material is deposited.

[0072]

[0071] In the case of the gas cushion roller, a first subgroup of gas outlets, i.e. open gas outlets, can be provided in the web guiding area of ​​the processing drum. A second subgroup of gas outlets, i.e. closed gas outlets, is provided outside the web guiding area. Since gas is only released in the web guiding area where gas is needed to form the hover cushion, no or little gas is released in the areas where the webs do not overlap, reducing gas waste and / or a better vacuum can be maintained with less strain on the pump system.

[0073]

[0072] According to some embodiments, which can be combined with other embodiments described herein, in addition to or instead of a subgroup of gas outlets, the outer surface of the treatment drum can be coated with a microporous surface. The microporous surface allows a small amount of cooling gas to flow from the inside of the treatment drum to the surface of the treatment drum. The cooling gas can form a gas cushion between the treatment drum and a web or foil that is guided over the treatment drum to deposit material thereon.

[0074]

[0073] Figure 6 shows a flow chart illustrating a method of coating a substrate in a vacuum chamber. In step 602, the method includes inducing a liquid material into a crucible for flash evaporation. According to some embodiments, the crucible can be a crucible for flash evaporation according to an embodiment of the present disclosure. The liquid material is flash evaporated in the crucible in step 604. In step 606, the flow rate of the liquid material is measured to control the deposition rate. For example, the flow rate can be measured with a flow meter according to an embodiment of the present disclosure. Furthermore, the flow rate of the liquid material can be directly correlated to the deposition rate because a vapor deposition apparatus as described herein can provide a material utilization rate of 95% or more.

[0075]

[0074] According to some embodiments, which can be combined with other embodiments described herein, the temperature of the crucible is constant and is not specifically used to adjust the deposition rate. The fill height in the crucible depends on the flow rate of the liquid material in the crucible.

[0076]

[0075] In the evaporator described herein, the evaporated material is guided from the crucible into a distribution enclosure, such as the enclosure 262 shown in Figures 3, 4, and 5. From the distribution enclosure, the evaporated material is guided through multiple nozzles onto or towards a substrate. For example, the substrate may be a thin web or foil, particularly in a roll-to-roll vacuum deposition apparatus. To provide very high material utilization, the material deposited on the substrate may be re-evaporated by a temperature control shield disposed between the distribution enclosure and the substrate.

[0077]

[0076] Figure 7 shows a flow chart illustrating a method for manufacturing a battery anode. According to some embodiments, the method for manufacturing a battery anode may include the method for coating a substrate in a vacuum chamber described with respect to Figure 6.

[0078] According to one embodiment, as shown in step 702, the method includes directing a web or foil in a vapor deposition apparatus according to an embodiment of the present disclosure. The vapor or foil may include or consist of an anode layer for a battery, particularly a thin-film battery. In step 704, a liquid lithium-containing material is provided in an evaporator of the vapor deposition apparatus. In step 706, the lithium-containing material or lithium is deposited on the web using the vapor deposition apparatus.

[0079] According to some embodiments, which may be combined with other embodiments described herein, in a method of manufacturing an anode for a battery, the web comprises or consists of copper. According to some implementations, the web can further comprise graphite and silicon and / or silicon oxide. For example, lithium can pre-lithiate a layer comprising graphite and silicon and / or silicon oxide.

[0080]

[0079] In particular, the following embodiments are described in this specification: Embodiment 1. A crucible for flash evaporation of a liquid material, comprising: one or more side walls; a reservoir portion below the one or more side walls, the reservoir portion having a first cross section of a first size; and a second cross section above the first cross section of a second size larger than the first size. A crucible comprising:

[0081] Embodiment 2. The crucible of embodiment 1, further comprising an opening for a conduit to guide liquid material within the crucible.

[0082] Embodiment 3. The crucible of embodiment 2, wherein the opening is provided in one or more side walls or in the bottom of the reservoir portion.

[0083] Embodiment 4. A crucible according to any one of embodiments 1 to 3, wherein the sidewall or walls and the reservoir portion are integrally formed.

[0084] Embodiment 5. The crucible of any one of embodiments 1-4, wherein the crucible comprises or consists of stainless steel, Mo, Ta, or a combination thereof.

[0085] Embodiment 6. A vapor passage for vaporized material provided at the top of one or more side walls. The crucible according to any one of embodiments 1 to 5, further comprising:

[0086] Embodiment 7. A crucible according to any one of the preceding embodiments, wherein the reservoir portion has a further cross section selected from the group consisting of a semicircular cross section, a cross section corresponding to a portion of an ellipse, and a tapered cross section, in particular a conical or frustoconical cross section.

[0087] Embodiment 8. The crucible of any one of embodiments 1 to 7, wherein at least one of the first cross-section and the second cross-section is circular, elliptical, or polygonal.

[0088] Embodiment 9. The crucible of any one of embodiments 1 to 8, wherein the first size of the first cross section is a first circumference of the first cross section and the second size of the second cross section is a second circumference of the second cross section.

[0089] Embodiment 10. A vapor deposition apparatus comprising the crucible according to any one of embodiments 1 to 9.

[0090] Embodiment 11. The vapor deposition apparatus of embodiment 10, further comprising a flow meter with a measurement unit external to the conduit for conducting the liquid material.

[0091] Embodiment 12. The vapor deposition apparatus of embodiment 11, wherein the flow meter is a Coriolis flow meter.

[0092] Embodiment 13. The vapor deposition apparatus of any one of embodiments 10 to 12, further comprising a flow valve having an adjustment element external to the conduit for the liquid material.

[0093] Embodiment 14. The vapor deposition apparatus of embodiment 13, further comprising a control valve configured to regulate the gas pressure at the flow valve.

[0094] Embodiment 15. The vapor deposition apparatus of embodiment 14, further comprising a flow restricting element configured to reduce gas pressure at the flow valve.

[0095] Embodiment 16. A controller configured to provide closed loop control, the controller being connected to a flow meter and a control valve. 16. The vapor deposition apparatus of embodiment 14 or 15, further comprising:

[0096] Embodiment 17. A vapor deposition apparatus configured to evaporate an alkali metal and / or alkaline earth metal, in particular lithium, comprising a flowmeter with a measuring unit external to a conduit for the liquid material.

[0097] Embodiment 18. The vapor deposition apparatus of embodiment 17, wherein the flow meter is a Coriolis flow meter.

[0098] Embodiment 19. The vapor deposition apparatus of embodiment 17 or 18, further comprising a flow valve having an adjustment element external to the conduit for the liquid material.

[0099] Embodiment 20. The vapor deposition apparatus of embodiment 19, further comprising a control valve configured to regulate the gas pressure at the flow valve.

[0100] Embodiment 21. The vapor deposition apparatus of embodiment 20, further comprising a flow restricting element configured to reduce gas pressure at the flow valve.

[0101] Embodiment 22. The vapor deposition apparatus of embodiment 20 or 21, further comprising a controller configured to provide closed loop control, the controller being connected to the flow meter and the control valve.

[0102] Embodiment 23. The vapor deposition apparatus according to any one of embodiments 10 to 22, further comprising a vacuum chamber for depositing a material onto a substrate within the vacuum chamber.

[0103] Embodiment 24. The vapor deposition apparatus of any one of embodiments 10-23, further comprising a vapor distribution enclosure in fluid communication with the crucible, particularly the crucible of any one of embodiments 1-9, the vapor distribution enclosure having a plurality of nozzles.

[0104] Embodiment 25. The vapor deposition apparatus of embodiment 23 or 24, wherein the pressure in the enclosure is at least an order of magnitude higher than the pressure in the vacuum chamber.

[0105] Embodiment 26. The vapor deposition apparatus of any one of embodiments 10 to 25, further comprising a heat shield.

[0106] Embodiment 27. The vapor deposition apparatus of any one of embodiments 10-26, further comprising a processing drum configured to support the substrate during material deposition.

[0107] Embodiment 28. A method for coating a substrate in a vacuum chamber, comprising inducing a liquid material into a crucible for flash evaporation, in particular into a crucible as described in any one of embodiments 1 to 9, flash evaporating the liquid material in the crucible, and measuring a flow rate of the liquid material to control a deposition rate of the material on the substrate.

[0108] Embodiment 29. The method of embodiment 28, wherein the fill height in the crucible depends on the flow rate of the liquid material.

[0109] Embodiment 30. The method of embodiment 28 or 29, further comprising directing the evaporated material from the crucible into a distribution enclosure and directing the evaporated material from the distribution enclosure through a plurality of nozzles on a substrate.

[0110] Embodiment 31. The method of any one of embodiments 28-30, further comprising re-evaporating material accumulated on a temperature-controlled shield disposed between the distribution enclosure and the substrate.

[0111] Embodiment 32. The method of embodiment 30, further comprising shielding a chamber wall of the vacuum chamber with a temperature controlled shield, wherein the temperature of the evaporator is greater than the temperature of the temperature controlled shield, and shielding at least a portion of the evaporator with a passively heated heat shield, wherein the temperature of the evaporator is greater than the temperature of the heat shield.

[0112] Embodiment 33. A method for manufacturing a battery anode, comprising the method for coating a substrate in a vacuum chamber according to any one of embodiments 28-32.

[0113] Embodiment 34. A method of making an anode for a battery, the method comprising: directing a web including or consisting of an anode layer in a vapor deposition apparatus according to any one of embodiments 10 to 27; and depositing a lithium-containing material or lithium on the web using the vapor deposition apparatus.

[0114] Embodiment 35 The method of embodiment 34, wherein the web comprises copper.

[0115] Embodiment 36 The method of embodiment 34, wherein the web comprises graphite and silicon and / or silicon oxide.

[0116] Embodiment 37. The method of embodiment 36, wherein the anode layer is pre-lithiated.

[0117]

[0080] While the foregoing description is directed to embodiments, other and further embodiments may be devised without departing from the basic scope of the disclosure, the scope of which is defined by the appended claims.

Claims

1. 1. A vapor deposition apparatus comprising:

1. A crucible for flash evaporation of a liquid material, comprising: one or more side walls; a reservoir portion below the one or more side walls, the reservoir portion having a first cross-section of a first size and a second cross-section above the first cross-section of a second size larger than the first size; A crucible comprising: a flow meter for measuring the flow rate of liquid material into the crucible; a flow valve for adjusting the flow rate of the liquid material to the crucible; a controller connected to the flow meter; Including, the controller receives as an input the flow rate of the liquid material to the crucible as measured by the flow meter and adjusts the flow valve to adjust the flow rate of the liquid material to the crucible, the flow rate of the liquid material to the crucible controlling an evaporation rate of the liquid material; the filling height of the reservoir portion is self-adjusting; a higher fill height in the reservoir portion corresponding to the second cross section results in a faster evaporation rate, and therefore the fill height is reduced until an equilibrium is reached; A lower fill height in the reservoir portion corresponding to the first cross section results in a slower evaporation rate, and therefore the fill height is increased until equilibrium is reached. Vapor deposition equipment.

2. The vapor deposition apparatus of claim 1 , wherein the crucible further comprises an opening for a conduit to direct the liquid material within the crucible.

3. The vapor deposition apparatus of claim 2 , wherein the opening is provided in the one or more side walls or in a bottom of the reservoir portion.

4. The vapor deposition apparatus of any one of claims 1 to 3, wherein the one or more side walls and the reservoir portion are integrally formed.

5. The vapor deposition apparatus of claim 4 , wherein the crucible comprises or consists of stainless steel, Mo, Ta, or combinations thereof.

6. The crucible has a vapor passage for the evaporated material at the upper end of the one or more side walls. The vapor deposition apparatus of claim 4 further comprising:

7. The reservoir portion is Semicircular cross-sections, cross-sections corresponding to parts of an ellipse, and tapered cross-sections 5. The vapor deposition apparatus of claim 4, further comprising a cross section selected from the group consisting of:

8. The vapor deposition apparatus of claim 4 , wherein at least one of the first cross-section and the second cross-section is circular, elliptical, or polygonal.

9. 5. The vapor deposition apparatus of claim 4, wherein the first size of the first cross-section is a first perimeter of the first cross-section and the second size of the second cross-section is a second perimeter of the second cross-section.

10. The vapor deposition apparatus of claim 1 , wherein the flow meter comprises a measurement unit external to a conduit for conducting the liquid material.

11. The vapor deposition apparatus of claim 10 , wherein the flow meter is a Coriolis flow meter.

12. The vapor deposition apparatus of claim 2, wherein the flow valve has an adjusting element external to the conduit for the liquid material.

13. A control valve configured to regulate the gas pressure in the flow valve. The vapor deposition apparatus of claim 12 further comprising:

14. a flow restricting element configured to reduce the gas pressure at the flow valve; The vapor deposition apparatus of claim 13 further comprising:

15. The vapor deposition apparatus of claim 13 , wherein the controller is configured to provide closed loop control and is connected to the flow meter and the control valve.

16. a vapor distribution enclosure in fluid communication with the crucible, the vapor distribution enclosure having a plurality of nozzles; The vapor deposition apparatus of claim 1 further comprising:

17. 1. A method of coating a substrate in a vacuum chamber, comprising: Inducing a liquid material into the crucible of a vapor deposition apparatus according to any one of claims 1 to 3 for flash evaporation; flash evaporating the liquid material in the crucible; measuring a flow rate of the liquid material to control a deposition rate of the material on the substrate; A method comprising:

18. The vapor deposition apparatus of claim 1 , wherein the crucible is configured to be heated to a temperature of 600° C. or greater during flash evaporation.

19. 10. The vapor deposition apparatus of claim 1, wherein the crucible is configured to maintain the liquid material at a temperature between 190° C. and 300° C. above the melting point of the liquid material.

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