JP7309882B2 - Vapor deposition apparatus and method for coating a substrate in a vacuum chamber - Google Patents

Description

TECHNICAL FIELD Embodiments of the present disclosure relate to substrate coating by thermal evaporation in a vacuum chamber. Embodiments of the present disclosure further relate to condensates that form on surfaces of a vacuum deposition apparatus. In particular, embodiments relate to vapor deposition apparatus and methods for coating substrates in vacuum chambers.

BACKGROUND Various techniques are known for deposition on substrates, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). Thermal evaporation can be used as a PVD process for deposition at high deposition rates. For thermal evaporation, a source material is heated to produce a vapor that can be deposited, for example, on a substrate. Increasing the temperature of the heated source material can increase the vapor concentration and promote faster deposition rates. The temperature to achieve high deposition rates depends on the physical properties of the source material, eg vapor pressure as a function of temperature, and the physical limits of the substrate, eg melting point.

For example, a source material deposited on a substrate can be heated in a crucible to produce vapor at a high vapor pressure. Vapor can be transported from the crucible to the coating volume within the heated manifold. A source material vapor can be dispensed from a heated manifold onto a substrate within the coating volume, such as a vacuum chamber.

A surface of the component, eg, a vacuum chamber wall of a vacuum chamber, may be exposed to the vaporized source material and may be coated. Frequent maintenance to remove condensate is not practical for high volume production, such as web coating on thin foil.

Additionally, source material on deposition apparatus components that are not intended to be coated can become contaminated and/or unrecoverable. Therefore, the cost of operating a vacuum deposition apparatus can be further increased due to inefficient source material utilization.

Accordingly, a vapor deposition apparatus for coating a substrate in a vacuum chamber, a method of evaporating a material, in which the maintenance period can be reduced and/or the minimum interval between preventive maintenance time periods can be reduced. , and methods. Furthermore, utilization of the source material is advantageously improved. Therefore, for example, manufacturing costs can be reduced.

SUMMARY In view of the above, there is provided a vapor deposition apparatus and 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 specification and accompanying drawings.

According to one embodiment, a vapor deposition apparatus is provided. A vapor deposition apparatus includes a vacuum chamber having a chamber wall; a temperature control shield configured to shield the chamber wall; an evaporator at least partially within the vacuum chamber, the evaporator having one or more nozzles extending through one or more openings.

According to one embodiment, a method is provided for coating a substrate within a vacuum chamber. The method comprises evaporating a material in a vacuum chamber; shielding at least a portion of the evaporator with a heat shield, the heat shield having an opening forming a passageway; Shielding the chamber wall of the chamber with a temperature control shield, wherein the temperature of the evaporator is higher than the temperature of the temperature control shield.

According to one embodiment, a method is provided for coating a substrate within a vacuum chamber. The method comprises evaporating a material in a vacuum chamber; and shielding a chamber wall of the vacuum chamber with a temperature control shield, wherein the temperature of the evaporator is higher than the temperature of the temperature control shield. shielding; shielding at least a portion of the evaporator with a passively heated heat shield, wherein the temperature of the evaporator is higher than the temperature of the heat shield; including.

So that the above features of the disclosure can be understood in detail, a more particular description of the disclosure briefly summarized above can be obtained by reference to the embodiments. The accompanying drawings relate to embodiments of the present disclosure and are described below.

FIG. 1A shows a schematic diagram of a vapor deposition apparatus having one or more temperature control shields or heat shields, according to embodiments of the present disclosure. FIG. 1B shows a schematic diagram of a further vapor deposition apparatus having one or more temperature control shields or heating shields or heat shields according to embodiments of the present disclosure. FIG. 2 shows a frame-like heat shield and a perspective view of the heat shield, according to an embodiment of the present disclosure. FIG. 3 shows a schematic diagram of a further vapor deposition apparatus having one or more temperature control shields or heating shields or thermal shields according to embodiments of the present disclosure. FIG. 4 shows a schematic diagram of a further vapor phase deposition apparatus, which is a roll-to-roll deposition apparatus according to embodiments of the present disclosure. FIG. 5 shows a flow diagram for describing a method of coating a substrate in a vacuum chamber according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS Reference will now be made in detail to various embodiments of the disclosure, one or more examples of which are illustrated in the drawings. In the following description of the drawings, same reference numbers refer to same components. Only differences relating to individual implementations are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Moreover, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to create yet a further embodiment. The description is intended to include such modifications and variations.

In the following description of the drawings, same reference numbers refer to same or similar components. Generally, only the differences with respect to individual implementations are described. Unless otherwise specified, a description of a portion or aspect in one embodiment applies equally to corresponding portions or aspects in another embodiment.

Embodiments of the present disclosure provide an apparatus and method for evaporative coating in a vacuum chamber. To deposit the source material onto the substrate by evaporation, the source material may be heated above the evaporation or sublimation temperature of the source material. Embodiments of the present disclosure provide reduced condensation on surfaces, such as surfaces other than the substrate, which may have lower temperatures. Such surfaces can be, for example, chamber walls.

Embodiments of the present disclosure provide a temperature controlled coating chamber environment, for example, to prevent coatings (eg, stray coatings) on shields, masks, and chamber walls. Advantageously improved substrate coating quality and yield can thus be provided in addition to longer operating times between preventative maintenance cycles.

According to one embodiment, a method is provided for coating a substrate within a vacuum chamber. The method includes evaporating a source material in a vacuum chamber. At least a portion of the evaporator is shielded by a heat shield, the heat shield having openings forming passageways. The chamber wall of the vacuum chamber is shielded with a temperature control shield, where the temperature of the evaporator is higher than the temperature of the shield.

According to another embodiment, a vapor deposition apparatus is provided. A vapor deposition apparatus includes a vacuum chamber having a chamber wall. An evaporator is provided in the vacuum chamber. A heat shield positioned to face the substrate to be coated and having an opening defining a passageway is provided. The evaporator includes a nozzle that extends through passages in the heat shield. The apparatus further includes a temperature control shield between the interior of the vacuum chamber and the chamber wall.

FIG. 1A shows a vacuum deposition apparatus 100. FIG. Vacuum deposition apparatus 100 includes a vacuum chamber 105 . Vacuum chamber 105 includes one or more chamber walls 150 . According to some embodiments, vaporizer 135 may be provided within vacuum chamber 105 or may be provided at least partially within vacuum chamber 105 . FIG. 1A shows the distributor 133 of the evaporator. The distributor may, for example, distribute steam provided to the distributor through the inlet opening 101 . A distributor may have one or more openings 182 . Vapor of the deposited source material can exit the distributor 133 through the opening. A source material is deposited on the substrate 110 . According to some embodiments, which can be combined with other embodiments described herein, one or more nozzles 136 can be provided in one or more openings 182, respectively.

In FIG. 1A, the distributor 133 is located at the bottom of the vacuum chamber 105 and the substrate 110 is located at the top. The deposited source material is directed from bottom to top. One or more sidewalls 150 extend from distributor 133 , ie, the bottom of vacuum chamber 105 , to the substrate location, ie, the top of vacuum chamber 105 . According to some implementations, which can be combined with other implementations described herein, one or more chamber walls of the vacuum chamber can be provided between the vaporizer and the substrate position. Sidewalls 150 may be protected from the coating by temperature control shields or frames 140 . The temperature control shield may be heated. Therefore, the material or source material deposited on the heating shield can be re-evaporated.

According to some implementations, a temperature control shield or heating shield can cover one or more chamber walls. In particular, the heating shield can cover multiple chamber walls. According to some embodiments, which can be combined with other embodiments described herein, the heating shield can be a frame or a temperature control frame. For example, a heating shield can surround the deposition zone through which vaporized material is directed toward the substrate. Additionally, the heating shield can form a continuous surface. According to embodiments, the heating shield may be thermally conductive to facilitate homogeneous or uniform heating of the heating shield.

According to embodiments, which can be combined with other embodiments described herein, the vapor deposition apparatus comprises a controller connected to a heater section for heating the temperature shield or heating shield. The controller controls the heating shield temperature to be below the evaporator temperature. The heater portion may be configured to heat the heating shield, and in particular may be configured to generate heat that is transferred to the heating shield. The heater portion can be arranged, for example, in a heating shield. Being placed on the heating shield can also be understood as being in direct and/or physical contact with the heating shield. The heater section can include, for example, heating coils, heating tubes, heating posts, heating lamps, and the like.

The heater portion may be disposed on the outer surface of the heating shield, where the outer surface of the heating shield faces the chamber wall and the inner surface of the heating shield faces the interior of the vacuum chamber. Also, the heater section can be integrated in the heating shield, in particular it can be arranged in the heating shield.

FIG. 1B shows a schematic diagram of a further vapor deposition apparatus having one or more frames or heat shields, according to embodiments of the present disclosure. Material 170 to be deposited, ie the source material, is vaporized in crucible 160 by heating material 170 . Materials 170 may include, for example, metals that have a vapor phase under given conditions, particularly lithium, metal alloys, and other vaporizable materials. According to further embodiments, the material may additionally or alternatively include magnesium (Mg), ytterbium (YB) and lithium fluoride (LiF). Evaporated material produced in crucible 160 may enter distributor 133 along the direction represented by arrow 137c. Distributor 133 can include, for example, channels or tubes that provide a transport system for distributing vaporized material along the width and/or length of the deposition apparatus. The distributor can have a "showerhead reactor" design.

As exemplarily shown, vaporized source material may be directed toward respective chamber walls 150 within distributor 133 along directions 137a and 137b. Directions 137 a and 137 b may be essentially parallel to planar substrate 110 , particularly parallel to surface 110 a of planar substrate 110 . For roll-to-roll coater coating drums, the directions 137a and 137b can be parallel to the axis of the coating drum, or parallel to the tangent of the coating drum at the shortest distance between the source and the drum. Evaporative material is injected from the vaporizer 135 into the interior 145 of the vacuum chamber 105 by nozzles 136 . Nozzle 136 is positioned within opening 182 of heat shield 180 . Evaporative material 185 ejected by nozzle 136 is deposited on surface 110 a of substrate 110 to form a coating of substrate 110 .

The heat shield 180 reduces radiant heat coming from the evaporator, eg, distributor 133, toward the substrate. According to an embodiment of the present disclosure, heat shield 180 includes opening 182 . According to some embodiments, which can be combined with other embodiments described herein, nozzle 136 of distributor 133 can extend through an opening in heat shield 180 .

According to some embodiments, which can be combined with other embodiments described herein, the opening of the heat shield may be larger than the corresponding dimensions of the nozzle. According to some embodiments, which can be combined with other embodiments described herein, the nozzle opening size is large enough to allow for additional thermal expansion compared to the nozzle dimensions. can do. Additionally or alternatively, the distributor or evaporator nozzles may not be in mechanical contact, particularly direct mechanical contact, with the heat shield. Thus, temperature transfer from the evaporator to the heat shield due to conductance can be reduced or avoided, eg, the heat shield can be supported by thermal insulation.

According to some implementations, which can be combined with other implementations described herein, the nozzle protrudes from the heat shield. In particular, the nozzle can protrude through the opening and protrude from the surface of the heat shield. Referring to the exemplary embodiment of FIG. 1B, the ratio between the nozzle length defined by upper end 136a of nozzle 136 and sidewall 134 of distributor 133 and the distance defined by heat shield 180 and sidewall 134 may be at least 1.1, particularly at least 1.3, or more particularly at least 1.5. Additionally or alternatively, the nozzle length is advantageously short, eg a ratio of 3 or less to provide good conductance at the nozzle tip.

According to an embodiment, which can be combined with other embodiments described herein, the ratio between the area of the sidewall of the distributor and the area of the interior surface of the vacuum chamber covered by the nozzle is at least 10. :1, especially at least 20:1, or more specifically greater than 50:1. By having the ratio between the sidewalls of the distributor and the nozzle area as described herein, the pressure within the distributor can be much higher than the pressure inside the vacuum chamber. In particular, the pressure in the distributor can be at least 10 times higher than the pressure inside the vacuum chamber, in particular at least 50 times higher, more in particular 100 times higher or more.

According to embodiments, which can be combined with other embodiments described herein, the evaporative material can comprise or consist of lithium, Yb, or LiF. According to embodiments, which can be combined with other embodiments described herein, the temperature of the evaporator and/or nozzle is at least 600° C., or in particular between 600° C. and 1000° C., or more particularly can be between 600°C and 800°C. According to embodiments, which can be combined with other embodiments described herein, the temperature of the heating shield can be between 450°C and 550°C, in particular about 500°C with a deviation of +/10°C.

According to embodiments, which can be combined with other embodiments described herein, the temperature of the heating shield is at least 100° C. below the temperature of the evaporator, in particular up to 300° C., more in particular at least Low from 100°C to 300°C.

According to embodiments, which can be combined with other embodiments described herein, the heat shield includes two or more heat shield layers. The heat shield layers can be spaced apart from each other. By arranging the heat shield layers apart from each other, the shielding effect can be enhanced. Additionally, the heat shield layer can be made of different materials with different heat transfer coefficients.

The temperature of the lower heat shield layer facing the sidewalls of the distributor can be higher than the temperature of the upper heat shield layer facing the substrate. The heat shield layer can be arranged, for example, attached to the side wall of the distributor, in particular by fixing pins. The pins may include a thermally insulating material such as an insulating alloy or ceramic. According to some embodiments, which can be combined with other embodiments described herein, the heat shield includes 1-10 heat shield layers. According to embodiments, one heat shield layer can be, for example, a metal sheet or a steel sheet. According to embodiments, the thickness of the heat shield layer may be between 0.1 mm and 1 mm, more particularly between 0.2 mm and 0.5 mm.

According to embodiments, which can be combined with other embodiments described herein, the heat shield is positioned between the sidewall and the substrate. The heat shield can be closer to the evaporator than the substrate.

According to an embodiment, which can be combined with other embodiments described herein, the heat shield is passively heated by the sidewalls of the evaporator, eg by radiation. The heat shield can be heated, for example, by radiant heat from the sidewalls of the evaporator, particularly the distributor. The term "passively" can be understood to mean that the heat shield is heated only by other components of the vacuum deposition apparatus. The heat shield may, for example, be configured to absorb, reflect and/or shield heat, particularly radiant heat from the sidewalls of the evaporator. By reducing the heat directed toward the substrate by the heat shield, as described herein, the substrate can be placed closer to the evaporator, which allows for a smaller, more compact vacuum chamber. design becomes possible.

Furthermore, by heating the heat shield, material deposited on the surface of the heat shield, for example by stray coating, may be re-vaporized. Stray coating material on the heat shield can be advantageously removed by re-evaporation as described herein. Additionally, re-evaporation of material from the heat shield can also result in a more uniform coating on the substrate.

FIG. 2 shows a perspective view of a frame-like shield and heat shield 180, according to an embodiment of the present disclosure. The heating shield forms a rectangular and/or square shaped frame 140 . Frame 140 is positioned on top of heat shield 180 . Heat shield 180 may form a flat or uniform top surface 183 . Frame 140 surrounds the perimeter of heat shield 180 . The frame 140 exposes the inside 142 of the frame 140 to the interior of the vacuum chamber. The distance between the upper edge 143 of the frame 140 to the top surface 183 of the heat shield 180 can be greater than the distance between the upper edge of the frame 140 and the substrate (not shown). According to some embodiments, which can be combined with other embodiments described herein, the shape of the frame and/or heat shield is configured to provide multiple openings or nozzles. For example, at least four rows of openings or nozzles can be provided. Additionally or alternatively, an array or pattern of openings and/or nozzles may be provided, wherein four or more openings and/or nozzles are arranged in two different directions, e.g. be.

According to embodiments, which can be combined with other embodiments herein, the heating shield covers most of the interior facing chamber wall of the vacuum chamber between the vaporizer and the substrate. Here the term "most part" means that the heating shield covers at least 50%, especially at least 75%, or more specifically 90% or more of the area of the total chamber wall area between the evaporator and the substrate. can be understood as

A controller is configured to actively control the temperature of the heating shield. Actively controlling may include controlling power supplied to the heater section and/or may include controlling the flow rate of heating liquid supplied to the heater section. The controller may be further configured to measure the temperature within the evaporator, crucible, heat shield and/or heat shield. Additionally, the controller may be configured to measure pressure within the evaporator and within the vacuum chamber. Additionally, the controller can be configured to control the evaporation rate within the crucible and/or vaporizer and/or the deposition rate of the vaporized material on the substrate. Respective parameters can be, for example, temperature, velocity, and pressure. Each parameter can be measured, for example, by a sensor arranged in each component of the vacuum chamber.

FIG. 3 shows a schematic diagram of a further vapor deposition apparatus having one or more frames or shields according to embodiments of the present disclosure. This apparatus has a vertical process direction, in contrast to the vapor deposition apparatus shown in FIG. 1A. Vacuum chamber 105 is connected to vacuum pump 210 . The vertically oriented distributor 133 is covered by a heat shield 180 facing the surface 100 a of the substrate 110 . Material is heated in crucible 160 , flows through a distributor, and through nozzle 136 into interior 145 of vacuum chamber 105 . The material can be re-evaporated by heat shield 140 as well as by heat shield 180 according to embodiments described herein.

FIG. 4 shows a schematic diagram of a further vapor deposition apparatus 400, which is a roll-to-roll deposition apparatus according to embodiments of the present disclosure. The substrate to be deposited can be a web 410 or foil guided by two drums 450 through the vacuum chamber 105 . The web 410 can move along the sidewall 134 of the distributor 133 and the interior 145 of the vacuum chamber facing the nozzle 136 . The substrate in this exemplary vapor deposition apparatus 400 can be web 410 . The vapor deposition apparatus and process components are similar to those described in other embodiments herein.

FIG. 5 shows a flow diagram for describing a method of coating a substrate in a vacuum chamber according to embodiments described herein. As indicated by box 501, the material is evaporated by an evaporator including, for example, a crucible as described herein. As indicated by box 502, at least a portion of the evaporator is shielded with a heat shield according to embodiments described herein. As shown in box 503, the chamber wall of the vacuum chamber is shielded with a temperature controlled heating shield, where the temperature of the evaporator is lower than the temperature of the heating shield according to embodiments described herein. expensive.

According to embodiments, which can be combined with other embodiments described herein, the temperature of the temperature control shield is actively controlled. According to embodiments, which can be combined with other embodiments described herein, the temperature of the temperature control or heating shield is set below the temperature of the evaporator.

A nozzle extending through a passageway in the substrate of the heat shield provides an outlet for vaporized material where it can be transferred from the vaporizer to the interior of the vacuum chamber.
The nozzle can allow a pressure difference between the interior of the chamber and the evaporator, in particular vapor pressure. In particular, the nozzle can allow the gas pressure inside the vacuum chamber to be lower than the vapor pressure in the evaporator.

Embodiments of the present disclosure have several advantageous effects. A temperature control shield can improve the deposition process inside the vacuum chamber. The temperature of the temperature control shield can be sufficiently high to reduce condensation of evaporative material on the chamber walls. Additionally, the temperature of the temperature control or heating shield can also be low enough to keep the heat load on the substrate low.

Additionally, stray coating material on the heat shield can be re-evaporated and deposited on the substrate. Additionally, re-evaporation of material from the heat shield can also result in a more uniform coating on the substrate. By reducing stray coating on the chamber walls with the heat shield, the vacuum deposition chamber can be operated at a higher throughput of vaporized material, which further increases the production rate of coated substrates.

A heat shield according to the embodiments described herein can reduce the heat load from the evaporator directed at the substrate, as described herein, where the substrate is located closer to the evaporator. can be used, which allows a smaller and more compact design of the vacuum chamber. Additionally, the evaporator can be operated at higher temperatures without damaging the substrate by radiant heat. In addition, material loss due to stray coatings on components other than the substrate inside the vacuum chamber, such as masks, shields and chamber walls, can be reduced by heat shields and re-evaporation on heat shields. Less stray coating can result in longer machine uptime between maintenance cycles and higher material utilization.

While the above description is directed to implementations, other and further implementations may be devised without departing from the basic scope of this disclosure, the scope of which is defined by the following claims: determined by

Claims (15)

a vacuum chamber having a chamber wall;
a temperature control shield configured to shield the chamber walls;
a heat shield facing the substrate to be coated, the heat shield having one or more openings;
an evaporator disposed at least partially within the vacuum chamber for evaporating material deposited on the substrate, comprising :
an evaporator comprising one or more nozzles extending through the one or more openings ;
the vaporizer having a sidewall facing the substrate, the nozzle being mounted on the sidewall;
the heat shield is positioned between the sidewall and the substrate;
The heat shield is passively heated by the sidewalls of the evaporator to a temperature below the temperature of the evaporator to allow re-evaporation of the material deposited on the heat shield by stray coating. Vapor deposition equipment. 2. The vapor deposition apparatus of claim 1, wherein the opening in the heat shield forms a passageway and the nozzle extends through the passageway. 3. The vapor deposition apparatus according to claim 1, wherein the temperature of said evaporator is higher than the temperature of said heat shield. 4. The controller according to any one of claims 1 to 3, further comprising a controller connected to a heater unit that heats the temperature control shield, the controller controlling the temperature of the temperature control shield to be lower than the temperature of the evaporator. or the vapor phase deposition apparatus according to any one of items. 5. The vapor deposition apparatus of any one of claims 1-4, wherein the heat shield comprises two or more heat shield layers. 6. The vapor deposition apparatus of any one of claims 1-5, wherein the temperature control shield covers the chamber wall . 7. The vapor deposition apparatus of any one of claims 1-6 , wherein the heat shield is closer to the evaporator than to the substrate . 8. The vapor deposition apparatus of any one of claims 1-7 , wherein the temperature control shield forms a frame positioned over the heat shield . 9. The vapor deposition apparatus of claim 8, wherein the distance between the upper edge of the frame and the top surface of the heat shield is greater than the distance between the upper edge of the frame and the substrate. A method for coating a substrate in a vacuum chamber comprising:
evaporating a material in the vacuum chamber provided in the vapor deposition apparatus of claim 1 ;
shielding at least a portion of the evaporator with the heat shield, the heat shield having the opening forming a passageway;
shielding a chamber wall of the vacuum chamber with the temperature control shield, wherein the temperature of the evaporator is higher than the temperature of the temperature control shield ;
The method of claim 1, wherein the material deposited on the temperature control shield is re-evaporated by heating the temperature control shield during coating of the substrate. 11. The method of claim 10 , further comprising actively controlling the temperature of said temperature control shield. 12. The method of claim 11 , wherein the temperature of the temperature control shield is set lower than the temperature of the evaporator. 13. A method according to any one of claims 10-12 , wherein the heat shield is passively heated by radiation . 14. Any one of claims 10 to 13 , further comprising setting a pressure inside the evaporator, wherein the pressure inside the evaporator is higher than the pressure inside the vacuum chamber. The method described in . A method for coating a substrate in a vacuum chamber comprising:
evaporating a material in the vacuum chamber;
shielding a chamber wall of the vacuum chamber with a temperature control shield, wherein the temperature of the evaporator is higher than the temperature of the temperature control shield;
shielding at least a portion of the evaporator with a heat shield, wherein the heat shield is passively heated to re-evaporate material deposited on the heat shield; wherein the temperature of is greater than the temperature of the heat shield ;
the heat shield is positioned between a sidewall of the evaporator and the substrate;
The heat shield is passively heated by the sidewalls of the evaporator to a temperature below the temperature of the evaporator to allow re-evaporation of the material deposited on the heat shield by stray coating. becomes
Method.

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