WO2012139714A1

WO2012139714A1 - Evaporator cell closure device for a coating plant

Info

Publication number: WO2012139714A1
Application number: PCT/EP2012/001424
Authority: WO
Inventors: Wolfgang Braun
Original assignee: Createc Fischer & Co. Gmbh
Priority date: 2011-04-12
Filing date: 2012-03-30
Publication date: 2012-10-18
Also published as: DE102011016814A1; DE102011016814B4

Abstract

The invention relates to a closure device (100) for an evaporator cell (200), comprising a cover plate (11) that is movable relative to the evaporator cell, that forms a barrier for a vapor stream (1) coming from the evaporator cell in a shut-off position and that releases the vapor stream (1) in an open position. Said closure device also comprises a side wall arrangement (12), which laterally shields an environment of the evaporator cell from the vapor stream (1) and is connected to the cover plate (11), such that a collecting chamber (10) and a flow chamber (20) are formed. The collecting chamber (10) is open at a collecting opening (13) on a lower face of the closure device, is closed on an upper face by the cover plate (11) and is installed such that in the shut-off position the vapor stream (1) enters the collecting chamber (10) through the collecting opening (13), and the flow chamber (20) is open on the lower face at an inlet opening (21) and on the upper face at an outlet opening (22) of the cover plate (11) and is installed such that in the open position the vapor stream (1) passes through the inlet and outlet openings. The invention further relates to an evaporator cell, to a coating plant and a method for the operation thereof.

Description

Evaporator cell closure device for a coating system

The invention relates to a closure device for an evaporator cell, in particular a closure (shutter) for an effusion cell. Furthermore, the invention relates to an evaporator cell equipped with the closure device and to a coating installation which contains at least one evaporator cell which is equipped with the closure device. Applications of the invention are given in the operation of coating systems for the production of thin layers, in particular molecular beam epitaxy systems (MBE systems).

Coating plants generally comprise a vapor source (or: evaporator cell), in particular an effusion cell, for producing a vapor jet of vaporization material and a substrate holder for receiving a substrate to be coated. The substrate is placed at a certain working distance from the vapor source so that atoms or molecules from the vapor jet condense or chemically react on the substrate to form a layer. The evaporant can be generally solid, liquid or gaseous, which is typically spoken of a steam source and a steam jet regardless of the state of aggregation of the vapor and the nature of the provision of the vaporization in the gaseous or vapor state. The coating of the substrate is typically carried out under vacuum conditions, in particular under ultrahigh vacuum (UHV), but may also be carried out, for example, under a vacuum. B. be realized in an inert gas. Conventional coating systems are predominantly designed so that the evaporator cell has a small working distance from the substrate, a wide radiation angle of the steam jet and a large angle of incidence relative to the normal of the coating layer (substrate level) in order to minimize the volume of the coating system substrates with the largest possible diameter and to use as many evaporator cells with large volume. In order to be able to control the conditions of a coating process, in particular the layer thickness or the sequence of layers, each evaporator cell is equipped with a closure. A conventional closure 100 ', shown by way of example in Figure 13 (prior art), comprises a cover plate 11' which is movable relative to an evaporator cell 200 '. The cover plate 11 'may be positioned over the mouth of the evaporator cell 200' (blocking position) to provide a barrier to the exit from the evaporator cell 200 '

Steam jet to form (see in particular Figure 13A). Furthermore, the cover plate 11 'may be withdrawn from the evaporator cell 200' to release the exiting jet of steam in an open position. The movement between the locked position and the open position is z. B. with egg ^¬ nem drive via a coupling element 30 ', which is provided for a forward thrust movement along the double arrow (see Figures 13A, 13B). Furthermore, the conventional Ver ^¬ evaporator equipped cell 200 'having a side wall 12', wel ^¬ surface 200 'surrounds a plurality of pages to a surrounding area of the evaporator cell 200', the beam direction of the evaporator cell to shield the exiting steam jet.

Conventional closures for evaporator cells, z. As shown in Figure 13, have a number of disadvantages. In the blocking position, evaporation material settles on the underside of the cover plate 11 'off. Solid vapor can form a thick layer which obstructs or blocks the closure. Liquid evaporant drips from the cover plate 11 ', so that the environment of the evaporator cell 200' is coated or its function is impaired. The same problems arise for the partition wall 12 ', with which a lateral crosstalk between adjacent evaporator cells to be suppressed. Coated partitions may also block the closure or affect the function of the evaporator cell. Furthermore, it is disadvantageous that the dividing wall 12 ¹ can not radially surround the jet direction of the steam jet on all sides, since a clearance for the actuation of the cover plate 11 'with the coupling element 30' must be kept free (see FIG. 13B). Due to this gap and due to a limited effectiveness of the remaining partition wall 12 ', material can settle on the inner walls of the coating system beyond the dividing wall 12'. To remove this material, the coater must be fully opened and completely disassembled, resulting in long maintenance times.

Another important disadvantage of the conventional technique results from strong temperature changes (so-called

"Shutter transients") that occur when opening or closing the shutter. The thermal radiation at the mouth opening of the evaporator cell 200 'in the beam direction changes depending on the arrangement of the cover plate 11' in the blocking position or the opening position. In the locking position the heat radiation is reflected back into the evaporator cell 200 ', so that the evaporating material stronger it warms ^¬ than in the open position. As a result, upon actuation of the closure, undesirable fluctuations in the evaporation rate are formed, which may need to be compensated by controlling the heat output of the evaporator cell. Further closures for evaporator cells are known from JP 2009- 256705 A, DE 20 2005 015 618 U1, JP 2008-081771 A and EP 1 788 112 A1. These closures, which are characterized by a more complex construction than in FIG. 13, are merely configured to influence the barrier action in the blocking position.

The abovementioned disadvantages are particularly critical for coating systems which are intended for a high material throughput, as is the case in particular in commercial semiconductor component manufacturing. The greater the amount of vaporized material, the more critical is the above deposition of material on the underside of the cover plate, on the bulkhead and on other interior walls of the coater, and the formation of the shutter transient. Thus, the size of the evaporator cell increases the dependence of the radiation characteristic of the steam jet on the fill level in the evaporator cell and at the same time the undesired effect of the shutter transient. In order to compensate for changes in the radiation pattern or the evaporation rate, empirical approaches based on test series have hitherto been required, the reliability of which, however, has proven to be limited in practice.

The object of the invention is to provide an improved closure device for an evaporator cell, with which disadvantages of conventional closures of evaporator cells are overcome. In particular, the closure device is intended to minimize unwanted material deposits and / or reduce the shutter transient. The object of the invention is also to provide an evaporator cell equipped with an improved closure device and an improved coating system. These objects are achieved by a closure device, an evaporator cell and a coating system having the features of the independent claims. Advantageous embodiments and applications of the invention will become apparent from the dependent claims.

According to a first aspect of the invention, a closure device for an evaporator cell (effusion cell) is provided, which comprises a cover plate and a side wall arrangement firmly connected to the cover plate. The cover plate and the side wall arrangement form a component which can be moved in a coating installation and which can be positioned, in particular relative to the evaporator cell, in a blocking position and in an opening position. In the blocking position, the closure device is configured such that the cover plate forms a barrier for a steam jet emerging from the evaporator cell. In the opening position, the closure device is adapted to release a steam jet from the evaporator cell, ie to form a passage for the steam jet. The side wall assembly fixedly connected to the cover plate includes side walls that protrude from the cover plate. The side walls of the side wall assembly extend in a direction different from the extension of the top plate. Typically, a flat cover plate is provided while the side wall assembly, ie, the side walls of the side wall assembly, are oriented perpendicular to the cover plate. The closure device has a top and a bottom. The upper side is a side facing away from the evaporator cell in use of the closure device, while the bottom is directed to the evaporator cell. Typically, in use, the closure device, in particular in their connection with a standing in a coating system holder or Drive device, at least one component of the surface normal of the upper side aligned vertically opposite to the gravitational direction, while at least one compo nent of the surface normal of the underside vertically in Gra vitationsrichtung has. Alternatively, the alignment may be reversed for overhead operation of the evaporator cell.

According to the invention, the side wall assembly is connected to the cover plate so that two chambers are formed. First, the side wall assembly forms a collection chamber with the cover plate. The collection chamber is a one-sided open space, which is bounded at the top of the closure device by the cover plate and the rest by side walls of the side wall assembly. At the bottom there is a catch opening. The collection chamber is open on the underside of the closure device and suitable for the steam jet to enter the collection chamber through the collection opening in the blocking position of the closure device. Thus, the closure device according to the invention is adapted to be positioned with respect to an evaporator cell so that the collecting opening of the collecting chamber is in the jet direction of the steam jet emerging from an opening of the evaporator cell. Advantageously, the steam jet can collect in the interior of the collection chamber and in particular precipitate, so that a transport of the vaporized material is blocked towards the substrate.

Second, a flow chamber is formed by the sidewall assembly with the cover plate. The flow chamber is a two-sided open space, which is bounded at the top of the closure device by the cover plate and the rest by side walls of the side wall assembly. At the bottom, the flow chamber is open with an inlet opening. Opposite the entrance opening, the cover plate in the flow chamber on an outlet opening, so that a steam jet can be passed through the flow chamber. Thus, the closure device according to the invention is suitable for being positioned above an evaporator cell in the opening position so that a steam jet emerging from the mouth opening of the evaporator cell can pass unhindered through the flow chamber to the substrate holder and in particular a substrate along the beam direction of the evaporator cell.

The closure device according to the invention has the advantage that the proportion of vaporization material is minimized, which deposits parasitically on inner walls or other parts of the coating system. The cover plate and the side wall arrangement of the closure device are arranged in such a way that as far as possible all the vaporized material deposited in a parasitic manner (ie not on the substrate) is deposited in or on a moving part in the coating installation. The closure device can be easily replaced, so that the effort to eliminate the parasitically separated evaporation material is minimized. As a result, the maintenance time of the coating system is shortened, and the service life between the maintenance intervals is extended. The closure device according to the invention is a three-dimensional, z. B. box-shaped cell closure. It offers the same function as the conventional closure with the cover plate provided at the top (eg according to FIG. By a movement relative to the fixed evaporator cell, z. B. a linear movement in the longitudinal direction of the arrangement of the two chambers or a pivoting movement, the closure device between the locking position and the open position is adjusted. In the opening position, the closing device outputs the flow of the vaporized material the underlying evaporator cell free, so that it can reach unhindered in the region of the surface to be vaporized, the substrate to be coated. In the blocking position, on the other hand, the flow of the vaporization material is interrupted, and the vaporization material deposits on the interior surfaces of the closure device facing the evaporator cell, in particular on the inner surfaces of the cover plate and the side wall arrangement in the collection chamber.

Compared to the conventional shutter in the blocking position, the vapor jet interrupting surface, ie the cover plate, has a greater distance from the mouth of the evaporator cell. An actuation of the closure device, ie a movement of the closure device thus leads to a reduced feedback on the thermal behavior of the evaporator cell. The shutter transient is reduced or negligible. Furthermore, the side walls of the side wall arrangement prevent lateral escape of the steam jet from the closure device. The side wall arrangement thus assumes the function of the partitions, which are fixed in the conventional closure between the evaporator cells, but according to the invention is part of the movable closure device. The closure device according to the invention has the following further advantages. Evaporation material exiting the evaporator cell while the closure device is in the blocking position may be collected in the collection chamber and removed during maintenance of the coating equipment together with the closure device. In order to remove parasitic vaporization material, it is not necessary, as hitherto, to provide a large-area access to the coating plant, since mechanical or chemical removal has been deposited Vaporizing material from the coating system is not required.

Furthermore, in the opening state of the closure device, the portion of the evaporation material that leaves the evaporator cell in a direction that is not directed at the substrate is likewise collected on sidewalls of the sidewall arrangement. Even in the opening position, the formation of parasitic deposits in the coating system is avoided. The material deposited in the flow chamber can also be removed from the coater during maintenance together with the closure device. Furthermore, the outlet opening in the cover plate at the top of the flow chamber fulfills a diaphragm function. The exit orifice may be shaped and dimensioned to restrict the vapor stream of the vapor so that only vapor (eg, atoms, molecules) moving in a straight line directly from the vaporiser cell to the substrate is allowed to pass through. As a result, the area lying next to the substrate in the interior of the coating installation is protected by a deposit of evaporating material.

The advantages of the three-dimensional closure device according to the invention become greater the greater the working state from the evaporator cell to the substrate. In this case, the opening angle of the evaporator cell with a constant substrate size (surface to be coated) and their angle to the normal of the surface to be vaporized is smaller. Thus, the closure device in the beam direction (longitudinal axis of the cell) can be larger, thereby increasing the advantages of the evaporator cell according to the invention.

According to a second aspect of the invention, the above object is achieved by an evaporator cell, which with a closure device according to the above-mentioned first aspect of the invention is equipped. The closure device is arranged to be movable relative to the evaporator cell. Since the side wall arrangement of the closure device assumes the function of the conventional partition walls between evaporator cells, an inventive evaporator cell can be arranged at a reduced distance from a further evaporator cell or other installations in the coating installation in comparison with the conventional technique. Thus, the number of evaporator cells can be increased in a given coating system and / or the internal volume of the coating system can be reduced.

According to a third aspect of the invention, the above-mentioned object is achieved by a coating installation, in particular an MBE installation, which contains at least one evaporator cell equipped with the closure device according to the abovementioned first aspect of the invention. Preferably, the coating system is equipped with at least one drive device with which the closure device of the at least one evaporator cell is movable relative to the evaporator cell, for. B. is linearly displaceable or pivotable. Another object of the invention is a method for coating a substrate in a coating system, wherein the closure device is used according to the above-mentioned first aspect of the invention. The process is characterized in particular by two operating phases of the coating. In a first operating phase, the closure device is in the blocking position, so that an exit of the steam jet from the evaporator cell is prevented. In this phase of operation no coating of the substrate or a coating of the substrate takes place from an adjacent evaporator cell. In a second operating phase, the closure device is arranged in the opening position, so that the vapor jet of the vaporization material is directed from the evaporator cell onto the substrate and the vaporization material deposits on the substrate.

According to a preferred embodiment of the invention, the side wall arrangement may have on a lower side of the closure device a bottom plate which extends over the underside of at least one of the collection chamber and the flow chamber. The bottom plate forms on the underside of the closure device a delimitation of the chamber (s), wherein in the bottom plate respectively corresponding to the collecting opening of the collecting chamber and / or the inlet opening of the flow chamber is formed. The bottom plate preferably extends over the extension of both chambers. Advantageously, through the bottom plate, which surrounds the collecting opening and / or the inlet opening, created a further collecting surface on which precipitate parts of the steam jet after a possible back reflection towards the evaporator cell or can fall on the parts of the deposited in the chambers evaporating. Thus, undesirable contamination of the evaporator cell or its environment can be avoided.

The retention function of the bottom plate can be further improved if, according to another variant of the invention, at least one of the collecting opening of the collecting chamber and the inlet opening of the flow chamber is equipped with a retaining ring. The retaining ring is a projection which extends along the edge of the collecting opening or the inlet opening and projects into the interior of the collecting or flow chamber. Advantageously, a retention volume is thus formed on the inside of the chambers on the bottom plate, with which both solid and liquid evaporating material can be reliably collected.

Alternatively, the closure device can be adapted so that vaporized material deposited in the collecting chamber and / or the flow chamber is returned to the evaporator cell. The return of evaporating material is particularly easy when evaporating liquid material. In this variant of the invention, the bottom plate in at least one of the two chambers is provided with a guide, can be passed to the evaporating material on the bottom plate corresponding to the collecting opening or to the inlet opening. The vaporized material conducted to the collecting opening or to the inlet opening can then fall or drip into the evaporator cell under the effect of gravity. The guide comprises z. B. a relative to the horizontal towards the respective opening inclined surface. Advantageously, the effectiveness of the use of the vaporization material and the service life of the coating system are significantly improved by the return of the vaporization in the evaporator cell.

According to a further advantageous embodiment of the invention, a targeted discharge of deposited vaporized material can also be provided in other parts of the chamber. For example, a draining device may be provided on the cover plate in the collection chamber and / or the flow chamber, with the evaporated material collected on the cover plate being directed respectively to the bottom plate, to the collection opening and / or to the inlet opening. When draining over the collecting opening and / or inlet opening, the vaporized material can be returned directly to the evaporator cell. When dripping onto the bottom plate, the vaporization material can be applied to it, if necessary using tion of the retaining ring, collected or recycled using the guide also in the evaporator cell. Another advantage of the invention is that the application of the closure device is not limited to evaporator cells for solid or liquid evaporating material. The invention can also be used with evaporator cells, with which at the operating temperature in the coating system gaseous vapor is passed to the substrate. The gaseous Evampfungsgut can z. B. after a chemical reaction with other substances on the substrate a

Forming a layer. For controlling an evaporator cell for gaseous evaporating material, the collecting chamber of the closure device is preferably connected to a pumping device. From the collection chamber leads a hollow conduit to the pumping device, which can be permanently installed in the coating plant. The hollow line is z. B. integrated into a holder or a coupling element of the closure device, so that advantageously also with the connection with the pumping device, a compact design is achieved.

According to a further advantageous embodiment of the invention, the closure device is equipped with a coupling element that serves the mechanical connection of the closure device with a part of the coating system, in particular with the drive device in the coating system. The coupling element is set up for a releasable fixation of the closure device in the coating system. It is preferably provided a coupling element with a snap or flange connection. This advantageously results in easy replacement of the closure device for maintenance purposes. The closure device can, for. B. be mounted on a removable flange, which can be easily removed and reassembled.

Advantageously, the closure device according to the invention can furthermore be used for charging the evaporator cell. For this purpose, the closure device according to a further variant of the invention comprises a funnel chamber, which is arranged adjacent to one of the collection and flow chambers. The closure device can be moved into a filling position relative to the evaporator cell, wherein in the filling position evaporating material can be filled through the funnel chamber into the evaporator cell. The funnel chamber comprises a two-sided open space, which is bounded by the cover plate and the side wall assembly and optionally also the bottom plate. The cover plate and possibly the bottom plate contain openings through which evaporating material can be passed into the evaporator cell. The inner walls of the side wall arrangement form a funnel opening, which tapers towards the underside of the closure device, by means of which a reliable introduction of evaporating material into the mouth opening of the evaporator cell is facilitated.

Further details and advantages of the invention will be described below with reference to the accompanying drawings. Show it:

FIG. 1 shows a schematic sectional view of a closure device according to the invention in the open position above an evaporator cell;

FIG. 2 shows a schematic perspective view of a closure device according to the invention in FIG the blocking position above an evaporator cell;

Figure 3: a schematic sectional view of a

Flow chamber of an inventive

Closure device;

FIG. 4 is a graphic representation of a radiation characteristic of an evaporator cell;

FIG. 5 shows a schematic sectional view of a further flow chamber of a further closure device according to the invention; Figures 6 and 7 are schematic sectional views of a collection chamber of a closure device according to the invention;

FIGS. 8 and 9 are schematic sectional views of further embodiments of the closure device according to the invention;

Figure 10: a schematic perspective view of a

Embodiment of the closing device according to the invention, in which the collecting chamber is connected to a pumping device;

Figure 11: a further embodiment of the closure device according to the invention, which is equipped with a funnel chamber;

FIG. 12 shows a schematic sectional view of a coating installation according to the invention; and Figure 13: schematic illustrations of a conventional closure of an evaporator cell (prior art).

Preferred embodiments of the invention are described below by way of example with reference to a closure device on an effusion cell in an MBE installation, wherein the closure device is arranged for a linear movement relative to the evaporator cell and a steam jet is directed vertically upward from the evaporator cell. It is emphasized that the embodiment of the invention is not limited to the application in the MBE system and the linear movement, but in the same way in other coating systems and / or with a pivoting movement (rotation) of the

Locking device is possible. Furthermore, the embodiment of the invention with an evaporator cell is possible, the beam direction is inclined relative to the vertical or the overhead, d. H. is operated with a vertically downwardly directed steam jet. In other words, the closure device oriented horizontally in the figures can be tilted relative to the horizontal. The embodiments of the invention will be described below with reference to details of the closure device. Details of the evaporator cell, the MBE plant and the methods of their operation are not described, as far as they are known from conventional coating techniques.

The figures illustrate the locking device according to the invention in schematic, not to scale representations. In the practical implementation of the invention, in particular the size and angle relationships depending on the conditions of use and in particular for a Optimization of the collection and shielding function of the closure device to be selected.

The illustrated in Figure 1 in a schematic sectional view of the first embodiment of the closure device 100 according to the invention comprises a cover plate 11 and a side wall arrangement 12 with three side walls 12.1, 12.2 and 12.3. The side wall assembly 12 is fixed to the cover plate 11, wherein a collecting chamber 10 and a flow chamber 20 are formed by the side walls 12.1, 12.2 and 12.3. The collection chamber 10 is bounded by the side walls 12.1 and 12.2 and a closed portion of the cover plate 11. The flow chamber 20 is bounded by the side walls 12. 2 and 12. 3 and a partial area of the cover plate 11 which is open with an outlet opening 22. In addition, the

Collection and flow chambers 10, 20 bounded by front and rear side walls, which are parallel to the plane and not shown in Figure 1 (see side walls 12.4, 12.5 of the embodiment shown in Figure 2). On the opposite side to the cover plate 11 (bottom of the

Closing device 100), the collecting and flow chambers are respectively open according to a collecting opening 13 and an inlet opening 21. The closure device 100 thus has the form of a three-dimensional box (cuboid shape) which extends in a longitudinal extension of the closure device and is divided by the side wall assembly 12 into the collection and flow chambers 10, 20. Connected to the side wall arrangement 12 is a coupling element 30 with which the closure device 100 can be fixed to a drive device (not shown, see FIGS. 10, 12). The coupling element 30 serves to hold the closure device 100 and move it relative to the evaporator cell 200. The evaporator cell 200, which is shown schematically and only in parts, comprises a crucible 210 with a crucible heater 220 and a cooling jacket 230. The crucible 210 is adapted for receiving solid or liquid evaporable material 2. The heater 220 may be configured as an electrical resistance heater and / or as an electron beam heater, as known from conventional evaporator cells. The cooling jacket 230 is configured for passive or active cooling and for shielding the environment of the crucible 210 and the heater 220 from radiated heat.

Upon actuation of the heater 220, the vaporization material 2 is heated until it is converted by vaporization or sublimation in the vapor state and exits through the mouth opening 211 of the crucible 210 to the outside. The movement of the vaporous vaporization material as a jet of steam 1 (shown schematically in FIG. 1, see also FIG. 3) follows a predetermined jet direction 3, whereby due to the geometry of the crucible 210 and the mutual collisions of the atoms or molecules in the vapor jet 1, a specific evaporator characteristic (spatial region, in which the evaporated material flows) is formed. The closure device 100 is arranged movably relative to the evaporator cell 200 and can be positioned in an open position (shown in FIG. 1) or in a blocking position (shown in FIG. 2). In the opening position, the flow chamber 20 is located in the jet direction 3 above the mouth opening 211 of the crucible 210, so that the steam jet 1 of the vaporization material enter the flow chamber 20 through the inlet opening 21 on the underside of the closure device 100 and the flow chamber 20 in at the outlet opening 22 Towards the substrate (not shown) can let. In the opening position, parts of the steam jet 1, which form lateral regions of the evaporator characteristic, are collected by the side walls 12. 2, 12. 3 and the inside of the cover plate 11 in the vicinity of the outlet opening 22. The outlet opening 22 forms an aperture for the evaporator characteristic, which is shaped so that only a predetermined part of the steam jet 1 is directed onto the substrate and unwanted precipitation in the vicinity of the evaporator cell and the substrate inside the coating system can be avoided. The outlet opening 22 is z. B. circular, while the collecting and inlet openings 13, 21 are rectangular.

In the blocking position, the closure device 100 is arranged so that the collection chamber 10 is positioned above the mouth opening 211 of the crucible 210. A steam jet 1 emerging from the crucible 210 is completely received by the collecting chamber 10. The vaporization material is deposited on the insides of the collection chamber 10, i. deposited on the side walls 12.1, 12.2 and the cover plate 11, so that an undesirable precipitation in the environment of the evaporator cell or other parts of the coating system is avoided. The closure device 100 is constructed of a metal or ceramic material. Any material which has sufficient temperature stability and, in particular, at the operating temperature of the closure device 100 exhibits neither a geometrical deformation nor an release of impurities, can be used. For high temperature

Evaporator cells whose operating temperature z. B. 2000 ° C, the closure device 100 is preferably made of tantalum or tungsten sheet. For evaporator cells with lower operating temperatures, such. B. evaporator cells for _2Q organic materials, the closure device 100 may be formed of steel or glass.

The dimensioning of the closure device 100 can, depending on the conditions of the specific application of the

Invention can be selected. For example, the collecting opening 13 or the inlet opening 21 are dimensioned such that they can completely absorb the steam jet emerging from the mouth opening 211 of the crucible 210. The length of the side walls 12.1, 12.2 and 12.3, ie the height of the closure device 100 in the jet direction 3 is selected so that the occurring at the inside of the cover plate 11 in the collection chamber 10 back reflection of thermal radiation does not affect the temperature in the crucible 210 or negligible little. The side walls 12.1 and 12.3 are thicker than the side wall 12.2 and z. B. hollow. In a concrete example, the closure device 100 for an evaporator cell 200 having a diameter of the mouth opening 211 of z. B. 2 cm have the following dimensions: height of the closure device 100 in the beam direction 2: 5 cm, and base of the collection and flow chambers 10, 20: 3 cm x 6 cm, distance of the bottom of the side wall assembly 12 of the evaporator cell 200: 5 mm , FIG. 2 illustrates a closure device 100 in a schematic perspective view. The closure device 100 has the box shape described above, which is formed by the side walls 12.1, 12.3, 12.4 and 12.5 and the cover plate 11 and in the interior by a further side wall (12.2 in Figure 1) into the collection chamber 10 and the flow chamber 20 is divided. FIG. 2 illustrates the blocking position in which the collecting chamber 10 is located above the mouth opening 211 of the crucible 210 of the evaporator cell 200, so that emergent, vaporous vapor is collected in the collection chamber 10.

The closure device 100 shown in Figures 1 and 2 is characterized by a particularly simple construction of the box shape. The collection and flow chambers 10, 20 are arranged side by side along the longitudinal extent of the closure device. The structure with a one-piece cover plate 11 which extends over the entire top of the closing device 100 and with planar side walls can be modified by z. B. a multi-part cover plate with different interconnected wall elements for closing the chambers and / or curved side walls are provided. Further modified features of the closing device are described below with reference to FIGS. 3, 5 and 6 to 11.

FIG. 3 illustrates the flow chamber 20 of a further embodiment of the closure device 100 according to the invention in a schematic sectional view (perpendicular to the longitudinal extent of the closure device). The flow chamber 20 is bounded by the side walls 12.4, 12.5, the cover plate 11 and additionally by a bottom plate 14. The bottom plate 14 is provided on the underside, ie on the side facing the evaporator cell 200 side of the closure device 100 and equipped with the inlet opening 21. In the opening position of the closure device 100, the inlet opening 21 in the bottom plate 14 and the outlet opening 22 in the cover plate 11 are arranged so that evaporating material 2 as vapor jet 1 from the crucible 210 of the evaporator cell 200 with the given jet direction 3 through the flow chamber 20 pass can. The inlet opening 21 and the outlet opening 22 are z. B. circular. The bottom plate 14 has a dual function. First, the inlet opening 21 of the flow chamber is provided with a predetermined diameter. Furthermore, 14 material can accumulate on the inside of the bottom plate, the z. B. is deposited after a multiple reflection in the flow chamber 20 or falls from a deposition 4 on the inside of the cover plate 11. Such collected material is exemplified by the reference numeral 5. The bottom plate 14 may be provided for delimiting the underside of the closure device 100 exclusively in the flow chamber 20 or in both chambers 10, 20 (see Figures 8, 9) or exclusively at the collection chamber 10.

The embodiment according to FIG. 3 is particularly well suited for the evaporation of sublimating vaporization material or vaporization material with a high melting point. Instead of a parasitic coating of parts of the coating system outside of the evaporator cell, the evaporating material is collected by evaporation in the interior of the flow chamber 20 with the closure device 100 according to the invention. The vaporized material is deposited in solid form on the insides of the flow chamber 20. In order to ensure the longest possible service life of the closure device 100 between two maintenance operations, the internal volume of the flow chamber 20 (and accordingly also the collection chamber 10) is maximized depending on the specific application conditions. Thus, in particular in the flow chamber 20 shown, a large amount of evaporating material can be precipitated, wherein the inlet and outlet openings 21, 22 are not or only negligibly reduced in size.

FIG. 3 diagrammatically illustrates the formation of an evaporating material deposition 4 on the inside of the cover plate 11 in a concrete example. The dimensioning of the exit and exit openings 21, 22 are based on the following considerations. Corresponding to the emission angle from the crucible 210 and the expansion of the vaporization product 2 in the crucible 210 (surface area of the source), the inlet opening is dimensioned such that no vaporization material can precipitate on the underside of the closure device 100. Furthermore, the deposition 4 can grow at the edge of the outlet opening 22 at an oblique angle to the center of the flow chamber 20. This growth is taken into account in the dimensioning of the outlet opening 22. From the capacity of the flow chamber 20 and the resulting service life, a thickness of the occupancy of the inside of the cover plate 11 in the beam direction 3 can be determined. From the emission angle and the thickness of the coverage results in an estimate of what diameter the outlet opening 22 must have, in order to ensure even at the end of a vaporization cycle, a complete deposition of the vaporized material on the substrate. In this estimation, the contribution may be indirect

Emission of evaporating material from the front insides of the crucible 210 are neglected, since this experience has shown to be negligibly small compared to the contribution of the direct emission of the vaporized 2. This is illustrated in Figure 4 using the example of a simulation of the flow of evaporating material 1. The curve representation in FIG. 4 shows the deposition of the vaporization product on a planar substrate arranged perpendicular to the crucible axis as a function of the distance from the substrate center. The deposition on the substrate is divided into three areas a, b and c. In the central region a, from which the entire surface of the vaporization material in the evaporator cell 200 is visible, the coating rate is approximately uniform, so that a uniform deposition or layer thickness is achieved. I'm at it adjoining inner edge region b, from which a part of the surface of the vaporization material in the evaporator cell 200 is visible, the coating rate drops strongly u approximately linearly. In the adjoining outer edge region c, only material emitted indirectly from the walls of the crucible 210 impinges on the substrate. In this range, the coating rate in relation to the inner region is negligible. The flow chamber 20 of a further embodiment of the closure device 100 according to the invention is illustrated in a schematic sectional view (along the longitudinal direction of the closure device) in FIG. As in FIG. 3, the flow chamber 20 is delimited by the side walls 12.4, 12.5, the bottom plate 14 with the inlet opening 21 and the cover plate 11 with the outlet opening 22. In addition, at the inlet opening 21, a retaining ring (collar) 15 is provided, with which on the inside of the bottom plate 14, a reservoir 14.1 is created for collected vapor 6. This embodiment of the invention is particularly well suited for the vaporization of liquid vapor.

During operation of the evaporator cell 200, evaporating material may precipitate on the inside of the flow chamber 20. Liquid vaporized material runs inside on the side walls 12.4, 12.5 down to the bottom plate 14. In the reservoir 14.1 between the retaining ring 15 and the lower portions of the side walls 12.4, 12.5, the liquid Verdampfungsgut 6 can collect. The height of the retaining ring 15 in

Beam direction is determined depending on the specific application conditions, in particular depending on the volume of the liquid Verdampfungsguts 6, which is to be retained in the flow chamber 20. additionally can be taken into account in the design of the height of the retaining ring 15 that during the movement of the closure device 100 overflow of the liquid vapor 6 over the retaining ring 15 is avoided by a wave formation.

The side of the retaining ring 15 facing the center of the entry opening 21 is inclined at an opening angle relative to the jet direction 3. The opening angle α is dimensioned so that the retaining ring 15 is not hit by the side of evaporating material, which faces the axis of symmetry of the crucible 210. The opening angle is z. B. 20 °.

FIG. 6 illustrates that the bottom plate 14 with the retaining ring 15 can also be provided in the region of the collecting chamber 10. Accordingly, in the sectional view shown in FIG. 6 (transversely to the longitudinal direction of the closure device 100), the collection chamber 10 is delimited by the side walls 12.4, 12.5, the closed cover plate 11 and the bottom plate 14 with the collection opening 13. By the retaining ring 15, a reservoir 14.1 is provided on the inside of the bottom plate 14 for receiving the liquid Verdampfungsguts 6. In order to ensure a directed movement of liquid evaporation material to this reservoir, the collection chamber 10 is additionally equipped with a drip tray 16.

The drip-off device 16 is adapted to guide evaporation material collected on the cover plate 11 to the base plate. Alternatively, the function of the dripping device 16 may be to conduct evaporating material to the collecting opening 13 (see FIG. 7). Alternatively or additionally, the dripping device 16 may also be provided in the flow chamber 20 (see FIG. 9). In the variant according to FIG. 6, the inside of the cover plate 11 is inclined in order to form the drip-off device 16. Material deposited on this inside runs under the action of gravity up to a drip edge 16. 1, which is located above the reservoir on the inside of the bottom plate 14. From the drip edge

16.1 drops 7 of liquid vapor can fall into the reservoir 14.1.

FIG. 7 illustrates the alternative variant in which the dripping device 16 is formed in such a way that deposited vaporized material runs to a drip tip 16.2 above the drip opening 13 and drops into the crucible 210 in the form of droplets 7. According to FIG. 7, the dripping device 16 is formed by a conical inside of the cover plate 11. The tip of the conical inside forms the drip tip 16.2, which is arranged centrally above the mouth opening 211 of the crucible 210. The variant according to FIG. 7 offers advantages if no value has to be placed on the highest purity of the vaporization product 2 and the closure device 100 is made of a material that is inert with respect to the vaporization product, ie. can be made with the evaporating material unreacted, pure material. Advantageously, then the material yield of the evaporation almost 100% and the life of the closure device practically unlimited.

The dripping from the dripping device 16 into the crucible 210 can be provided continuously while the closure device 100 is in the blocking position. When the movement of the closure device 100 is provided to the open position, further dripping from the drip tip may occur

16.2 be disturbing. To prevent this, at least during the movement or permanently, respectively, before moving the closure device 100 from the blocking to the opening position (or vice versa) a brief step movement of the closure device 100 with changing direction of movement (short reciprocating movement of the closure device) can be provided by the dripping of the evaporating material is triggered targeted.

Since a dripping of liquid evaporating material or a breaking off of solid evaporating material can not be precluded when the collecting chamber 10 is in the open position or the flow chamber 20 in the locking position of the closure device 100 adjacent to the crucible 210 of the evaporator cell 200, the evaporator cell 200 can additionally with Collecting containers 220 may be equipped. The arrangement of the collection container 220 laterally adjacent to the crucible 210 of the evaporator cell is schematically illustrated in FIG. The distance of the collecting container 220 from the crucible 210 is equal to the distance between the collecting and inlet openings 13, 21 of the collecting and flow chambers 10, 20. Contrary to the illustrated variant, only one collecting container 220 may be provided on the side of the crucible 210, where the collection chambers 10 are in the open position of the closure device 100 (illustrated in FIG. 8). Furthermore, it is preferably provided that the collecting container 220 are formed by movable crucible or pots, which can be removed or replaced by a maintenance opening from the coating system.

According to a further embodiment of the invention can min- least one of the collection and flow chambers 10, 20 may be equipped with egg ^¬ ner guide means 17 which is adapted to the bottom plate 14 precipitated evaporating toward the receiving port 13 of collection chamber 10 and / or the inlet opening 21 of the flow chamber 20 to pass. In fi gur 9 is shown by way of example a variant in which both chambers 10, 20 are each equipped with a guide 17. To form the guide 17, the inside of the bottom plate 14 around the collecting and Eintrittsöff- openings 13, 21 each formed funnel-shaped. Thus, liquid evaporant can drain from the guide 17 and be collected in the crucible 210 of the evaporator cell 200. In addition, at the lower edge of the respective opening, a cylindrical or funnel-shaped drip edge 17. 1 can be provided which, for example, can be attached to the guide device 17 of FIGS

Flow chamber 20 is shown in Figure 9. The drip edge 17.1 prevents the evaporating material from running along the underside of the closure device 100. Since the collecting opening 13 and the inlet opening 21 typically have a larger diameter than the mouth opening 211 of the crucible 210, the drip edge 17.1 on the bottom plate 14 is outside an extension of the inner walls of the crucible 210 (see 212 in Figure 9). In order nevertheless to ensure a secure absorption of vaporization material in the crucible 210, the crucible 210 is equipped at its mouth opening with a rim widening 213. The edge widening 213 includes a portion of the crucible 210 in which the diameter of the crucible widens toward the mouth 211. It is e.g. a funnel-shaped extending from the symmetry axis of the crucible 210 extending edge region. The edge widening 213 is preferably additionally heated in order to facilitate drainage of liquid vaporized material into the crucible 210. For this purpose, a heater 214 is provided in the vicinity of the orifice in the edge widening 213.

The closure device 100 according to the invention is particularly suitable for controlling the flow of gaseous steaming good. When the collecting chamber 10 is connected to a pumping device 40, gaseous evaporating material in the blocking position can be pumped out through the collecting chamber 10. This embodiment of the invention, which is illustrated in a schematic perspective view in FIG. 10, has the particular advantage that a large flow ratio between the open and closed positions can be realized, since the gaseous evaporating material in the blocking position of the closure device 100 is effectively removed from the coating system can be pumped out.

The closure device 100 comprises the collection chamber 10 and the flow chamber 20, which are connected via a coupling element 30 with a drive device 50 (shown schematically) in the coating system. The flow chamber 20 is located at the free end of the closure device 100, while the collection chamber 10 is connected to the coupling element 30. The coupling element 30 comprises a hollow conduit which extends from the collection chamber 10 to the pumping device 40. The pumping device 40 includes e.g. a connected to the coating plant vacuum pump 41. The drive means 50 includes z. As a motor drive or a linkage, which is operated by a motor outside the vacuum chamber of the coating plant.

Gaseous evaporating material is not provided from a crucible, but by means of a nozzle 215 in the coating system. In the collection chamber 10 is a guide wall 18, with which the gaseous evaporating material, which enters the blocking position shown by the nozzle 215 through the collecting opening 13 into the collecting chamber 10, is deflected towards the coupling element 30. The baffle 18 includes, for example, a flat, inclined or a quarter-circle curved surface, which redirects the gas flow. In the opening The gaseous evaporating material flows through the inlet and outlet openings 21, 22, the flow chamber 20 to the substrate. Notwithstanding the illustration in Figure 10, alternatively or additionally, a compound of the

Passage chamber with the coupling element. Advantageously, this makes it possible to also feed evaporated material within the flow chamber to the pumping device. FIG. 11 illustrates a further embodiment of the closure device 100 according to the invention, in which a funnel chamber 60 is provided in addition to the collection chamber 10 and the flow chamber 20. In this embodiment of the invention, the closure device 100 additionally fulfills the function of filling the evaporator cell 200 with solid or liquid evaporant. The funnel chamber 60 is disposed adjacent to the collection or flow chamber 20 and formed with an inner funnel-shaped surface 61. The closure device 100 may be moved to a fill position (shown in FIG. 11) in which the funnel chamber 60 is located above the evaporator cell 200. In the filling position, the evaporator cell 200 can be filled by evaporating material from a refill (not shown) is placed on the top of the closure device 100 in a funnel opening 62. Through the funnel-shaped surface 61 in the funnel chamber 10, the vaporization material is centered in the crucible 210 of the evaporator cell 200 with high accuracy. Advantageously, the hopper chamber 60 that un ^¬ ter vacuum evaporating can be refilled without particularly high demands on the precision of setting of the refill. Through the funnel form results in a high tolerance against when dumping possibly evasive Evaporative.

The evaporation material is for the use of the closure device 100 according to FIG. 11 z. B. in liquid form or as granules with a grain size below 5 mm, so that wedging in the interior of the hopper chamber 60 is avoided. In order to further minimize the likelihood of wedging, the hopper chamber 60 is preferably formed in the upper part with a large opening angle and in the lower part also with an opening angle. Furthermore, the refill device can be equipped with a tool for loosening up possibly stuck evaporating material.

FIG. 12 illustrates, in a schematic sectional view, an embodiment of a coating installation 300 according to the invention with a vacuum chamber 310. In the vacuum chamber 310, at least one substrate holder 320 is arranged, which is set up to receive a substrate 8 to be coated. Furthermore, a plurality of evaporator cells 200 are arranged in the vacuum chamber 310, which are each equipped with the closure device 100 according to the invention. The vacuum chamber 310 has a pump port 330 for connection to a vacuum pump (not shown) and a lock device. The lock device comprises at least one substrate lock 341, which is set up to transfer the substrate 8 between the interior of the vacuum chamber 10 and the external environment. Furthermore, at least one additional lock 342 may be provided, which is configured for access into the interior of the vacuum chamber 310, for example for the supply of evaporation material or for the discharge of precipitate from the closure device. It is not mandatory for the closure devices 100 Provide locks. Rather, it may be sufficient to retract the closure devices 100 from the evaporator cells 200 in respective shuttle units 343 which are connected to the wall of the vacuum chamber 310 and from which the supply of evaporation material from the outside or the discharge of precipitate to the outside. The shutter units 343 can z. Example, as described in the unpublished German patent application DE 10 2011 013 245 on the priority date of the present invention.

It is emphasized that FIG. 12 illustrates the coating system 300 and its components only schematically. In a specific embodiment, the coating system 300 is equipped with other equipment parts, as is known from conventional coating technology, such. B. with

Sensors, manipulators. The coating system 300 comprises, for example, an MBE plant.

For operation of the coating system 300, the evaporator cells 200 are charged with evaporating material and the substrate 8 is fixed to the substrate holder 320. In the vacuum chamber 310, a reduced operating pressure, e.g. Ultra high vacuum set. The evaporator cells 200 are heated, so that evaporation material is in each case converted into the gaseous state. During heating, the closure devices 100 are in the blocking position, that is to say any escaping vaporization material is collected in the collecting chambers of the closure devices 100. Subsequently, the closure devices 100 are moved in common, in groups, or individually in succession to form a plurality or individual ones

Evaporator cells 200 release. The closure devices 100 are moved into the open position, so that the steam jet can flow to the substrate 8 and the evaporation material can be deposited on the substrate 8. If, for example, through a visual observation, a sensor or the monitoring of other operating parameters is found that one of the closure devices 100 is completely loaded with parasitically deposited evaporate, the relevant evaporator cell 200 is turned off. When the evaporator cell 200 is cooled and no further evaporating material emerges, the closure device 100 is decoupled from the drive device 50 and with a manipulation tool

(not shown) through the lock 342 in the external environment of the vacuum chamber 310 transferred. After a regeneration of the closure device 100 (removal of the parasitically separated evaporation material), the closure device 100 can be used again in the coating installation 300.

The features of the invention disclosed in the description, the drawings and the claims may be significant both individually and in combination for the realization of the invention in its various forms.

Claims

CLAIMS 1. A closure device (100) for an evaporator cell (200), comprising:

a cover plate (11) which is movable and arranged relative to the evaporator cell (200) to form a barrier in a blocking position for a steam jet (1) emerging from the evaporator cell (200) and in an opening position the steam jet (1 ), and

a sidewall arrangement (12) arranged to shield an environment of the evaporator cell (200) laterally from the steam jet (1),

characterized in that

- The side wall assembly (12) is connected to the cover plate (11), so that a collecting chamber (10) and a flow chamber (20) are formed, wherein

- The collection chamber (10) on an underside of the closure device (100) at a collecting opening (13) is open and at an upper side of the closure device (100) through the cover plate (11) is closed and is arranged that in the locked position of the Steam jet (1) enters the collecting chamber (10) through the collecting opening (13), and

- The flow chamber (20) at the bottom at an inlet opening ^¬ (21) and at the top at an outlet opening (22) of the cover plate (11) is open and is arranged that in the open position of the steam jet (1) through the inlet - and outlet openings (22) passes.

2. Closure device according to claim 1, wherein

- The side wall assembly (12) at an underside of the closure device (100) connected to a bottom plate (14) is, in which at least one of the collecting opening (13) and the inlet opening (21) are formed.

3. Closure device according to claim 2, wherein

- The bottom plate (14) is provided on at least one of the collecting opening (13) and the inlet opening (21) with a retaining ring (15), respectively, the collecting opening (13) or the inlet opening (21) surrounds.

4. Closure device according to one of the preceding claims, in which

- The cover plate (11) is provided in at least one of the collecting chamber (10) and the flow chamber (20) with a dripping device (16) which is arranged on the cover plate (11) collected evaporant to the collecting opening (13) to guide to the bottom plate (14) or to the inlet opening (21).

5. Locking device according to one of claims 2 to 4, in which

- The bottom plate (14) is provided in at least one of the collecting chamber (10) and the flow chamber (20) with a guide (17) which is adapted to the bottom plate (14) collected vaporized material to the collecting opening (13) or to lead to the inlet opening (21).

6. Closure device according to one of the preceding claims, in which

- At least one of the collection chamber (10) and the flow chamber (20) is connected to a pumping device (40).

7. Closure device according to one of the preceding claims, comprising - A coupling element (30) which is adapted for releasably fixing the closure device (100) in a coating system (300).

8. Closure device according to one of the preceding claims, comprising

- A funnel chamber (60), which is arranged in a filling position of the closure device for introducing evaporating material (2) in the evaporator cell (200).

9. Evaporator cell (200), comprising:

- A crucible (210) for receiving evaporating material (2), and

- A closure device (100) according to one of the preceding claims.

10. evaporator cell according to claim 9, wherein

- The crucible (210) at an orifice (211) has an edge widening (213) at which widens the diameter of the crucible (210) funnel-shaped.

11. Coating plant (300), comprising:

- At least one evaporator cell (200) which is equipped with a closure device (100) according to one of claims 1 to 8.

12. Coating plant according to claim 11, comprising

- A drive device (50) with which the closure device (100) relative to the evaporator cell (200) is movable.

13. A method for operating a coating system (300) with at least one evaporator cell (200), wherein the Closing device (100) according to one of claims 1 to 8 is used, comprising:

- An operating phase in which the closure device (100) is arranged in the blocking position, so that an exit of the steam jet (1) from the evaporator cell (200) is prevented, and

an operating phase in which the closure device (100) is arranged in the open position, so that the vapor jet (1) of the vaporization material is directed from the evaporator cell (200) onto a substrate (8) and the vaporization material is deposited on the substrate ( 8) precipitates.

14. Use of a closure device (100) according to one of claims 1 to 8 during operation of a coating installation (300).