DE102011016814B4 - Evaporator cell closure device for a coating system - Google Patents

Abstract

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) in a blocking position for a steam jet (1) exiting the evaporator cell (200) Forming a barrier and releasing the jet of steam (1) in an open position; and a sidewall arrangement (12) arranged to shield an environment of the evaporator cell (200) laterally of the steam jet (1) and including sidewalls extending in one direction extend, which differs from the extent of the cover plate (11), wherein - the side wall assembly (12) with the cover plate (11) is connected, so that a collecting chamber (10) is formed on a bottom 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 blocking position of the steam jet (1) d urch the collecting opening (13) enters the collecting chamber (10), characterized in that - the side wall assembly (12) is further connected to the cover plate (11), that a flow chamber (20) is formed by the cover plate (11 ) and side walls (12.2, 12.3) of the side wall assembly (12) is limited, wherein - the flow chamber (20) at the bottom of the closure device (100) at an inlet opening (21) and at the top of the closure device (100) at an outlet opening ( 22) of the cover plate (11) is open and is arranged that - in the open position, the steam jet (1) passes through the inlet and outlet openings (22).

Description

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 equipment for the production of thin films, in particular molecular beam epitaxy equipment (MBE plants).

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 ultra-high vacuum (UHV), but can also z. 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 plane (substrate level) to the smallest possible volume of the coating system substrates with the largest possible diameter and as many To be able to use evaporator cells with a 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 ' who exemplifies in 13 (Prior Art), comprises a cover plate 11 ' that is relative to an evaporator cell 200 ' is mobile. The cover plate 11 ' may be above the mouth of the evaporator cell 200 ' be positioned (blocking position) to provide a barrier for the out of the evaporator cell 200 ' Forming steam jet to form (see in particular 13A ). Furthermore, the cover plate 11 ' from the evaporator cell 200 ' be withdrawn to release the exiting steam jet in an open position. The movement between the locked position and the open position is z. B. with a drive via a coupling element 30 ' which is responsible for a feed movement along the double arrow (see 13A . 13B ) is provided. Furthermore, the conventional evaporator cell 200 ' with a side wall 12 ' equipped, which the beam direction of the evaporator cell 200 ' from several sides surrounds to an environment of the evaporator cell 200 ' shield from the exiting steam jet.

Conventional closures for evaporator cells, z. B. according to 13 , have a number of disadvantages. In the blocking position, evaporation material settles on the underside of the cover plate 11 ' from. Solid vapor can form a thick layer which obstructs or blocks the closure. Liquid evaporates drips from the cover plate 11 ' off, leaving the environment of the evaporator cell 200 ' coated or whose function is impaired. The same problems arise for the partition 12 ' with which a lateral crosstalk between adjacent evaporator cells should be prevented. Coated partitions may also block the closure or affect the function of the evaporator cell. Furthermore, it is disadvantageous that the partition 12 ' The beam direction of the jet of steam can not radially surround all sides, as a free space for the actuation of the cover plate 11 ' with the coupling element 30 ' must be kept free (see 13B ). Due to this gap and due to a limited effectiveness of the remaining partition 12 ' can material on the inner walls of the coating system beyond the partition 12 ' drop. 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 severe temperature changes (so-called "shutter transients") that occur when opening or closing the shutter. The thermal radiation at the mouth of the evaporator cell 200 ' in the beam direction changes depending on the arrangement of the cover plate 11 ' in the locked position or the open position. In the blocking position heat radiation is in the evaporator cell 200 ' reflected back, so that the evaporating material heated more 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.

The disadvantages mentioned are particularly critical for coating systems that are suitable for a high Material throughput are provided, as is the case in particular in the commercial semiconductor device 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, with the size of the evaporator cell, 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 increases. 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 JP 2008-081771 A1 forms a closure device according to the preamble of claim 1. Further closure devices are the publications JP 2009-256705 A . DE 20 2005 015 618 U1 , such as EP 1 788 112 A1 refer to.

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 assembly form a movable component in a coating system, which is movable in particular relative to the evaporator cell and in a blocking position and in an open 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 open position, the closure device is adapted to release a steam jet from the evaporator cell, i. H. 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 sidewalls of the sidewall assembly extend in a direction that deviates from the extent of the cover plate. Typically, a flat top plate is provided while the side wall assembly, i. H. the side walls of the side wall assembly are aligned 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 of the closure device, particularly when connected to a fixture or drive means, at least one component of the surface normal of the top is vertically opposed to the gravitational direction, while at least one component of the surface normal faces vertically in the direction of gravity. 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 with the cover plate forms a collection chamber. 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 of a collection opening is provided. 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 arranged 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 a mouth 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 inlet opening, the cover plate in the flow chamber on an outlet opening, so that a steam jet through the flow chamber can be passed. Thus, the closure device according to the invention is suitable for being positioned above an evaporator cell in the opening position such that a steam jet issuing 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 jet 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 evaporative material deposited in a parasitic manner (that is to say 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 13A ). 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 open position, the closure device releases the flow of vaporization material from the evaporator cell below so that it can reach the substrate to be vaporized unhindered in the region of the surface to be vaporized. In the blocking position, however, the flow of the vaporized material is interrupted, and the vaporized material deposits on the evaporator cell facing inner surfaces of the closure device, in particular on the inner surfaces of the cover plate and the side wall assembly in the collection chamber.

Compared to the conventional closure, in the blocking position, the area interrupting the jet of vapor, i. H. the cover plate, a greater distance from the mouth opening of the evaporator cell. Actuation of the closure device, d. H. 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 to provide a large-area access to the coating plant, since mechanical or chemical removal of vaporized material from the coating plant which is deposited is not necessary.

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 to the substrate is also 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 deposition with 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-mentioned object is achieved by an evaporator cell provided with a closure device according to the first mentioned above Viewpoint 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 takes over the function of the conventional partitions between evaporator cells, an evaporator cell according to the invention can be arranged at a reduced distance from a further evaporator cell or other internals in the coating system in comparison to 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 assembly may have at a bottom side of the closure means a bottom plate extending 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, a further collecting surface is created by the bottom plate, which surrounds the collecting opening and / or the inlet opening, on which parts of the steam jet after a possible Rückrefflektion reflected down to the evaporator cell or can fall down on the parts of the deposited in the chambers Evaporative. 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 is provided in at least one of the two chambers 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 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. At the Dripping on the bottom plate, the evaporating material can be collected at this, possibly using the retaining ring, or also recycled using the guide 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 form a layer. For controlling an evaporator cell for gaseous evaporating material, the collecting chamber of the closing device is preferably connected to a pump 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 fixing of the closure device in the coating installation. It is preferably provided a coupling element with a latching 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 removed and reassembled easily.

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:

1 a schematic sectional view of a closure device according to the invention in the open position over an evaporator cell;

2 a schematic perspective view of a closure device according to the invention in the blocking position over an evaporator cell;

3 a schematic sectional view of a flow chamber of a closure device according to the invention;

4 : a graphical representation of a radiation characteristic of an evaporator cell;

5 a schematic sectional view of a further flow chamber of a further closure device according to the invention;

6 and 7 : schematic sectional views of a collection chamber of a closure device according to the invention;

8th and 9 : schematic sectional views of further embodiments of the closure device according to the invention;

10 a schematic perspective view of an embodiment of the closure device according to the invention, in which the collecting chamber is connected to a pumping device;

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

12 a schematic sectional view of a coating system according to the invention; and

13 : schematic illustrations of a conventional closure of an evaporator cell (prior art).

Preferred embodiments of the invention will be described below by way of example with reference to a closure device on an effusion cell in an MBE installation, wherein the closure device for a linear movement is arranged relative to the evaporator cell and a steam jet from the evaporator cell is directed vertically upwards. 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 closure device is possible. Furthermore, the embodiment of the invention with an evaporator cell is possible, whose jet direction is inclined relative to the vertical or which is operated overhead, ie 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 closure 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 may be selected depending on the conditions of use and in particular for an optimization of the collecting and shielding function of the closure device.

In the 1 in a schematic sectional view illustrated first embodiment of the closure device according to the invention 100 includes a cover plate 11 and a sidewall arrangement 12 with three side walls 12.1 . 12.2 and 12.3 , The sidewall arrangement 12 is on the cover plate 11 fastened, passing through the side walls 12.1 . 12.2 and 12.3 a collection chamber 10 and a flow chamber 20 be formed. The collection chamber 10 is through the sidewalls 12.1 and 12.2 and a closed portion of the cover plate 11 limited. The flow chamber 20 is through the sidewalls 12.2 and 12.3 and one with an exit port 22 opened portion of the cover plate 11 limited. In addition, the collection and flow chambers 10 . 20 bounded by front and rear side walls which are parallel to the plane of the drawing and in 1 not shown (see sidewalls 12.4 . 12.5 the in 2 shown embodiment). On the cover plate 11 opposite side (bottom of the closure device 100 ) are the collection and flow chambers each corresponding to a collecting opening 13 and an entrance opening 21 open.

The closure device 100 thus has the shape of a three-dimensional box (cuboid shape) extending in a longitudinal extension of the closure device and through the side wall assembly 12 into the collection and flow chambers 10 . 20 is divided. With the sidewall arrangement 12 is a coupling element 30 connected to the closure device 100 on a drive device (not shown, see 10 . 12 ) is fixable. The coupling element 30 serves to hold the closure device 100 and their movement relative to the evaporator cell 200 ,

The evaporator cell 200 , which is shown schematically and only in part, comprises a crucible 210 with a crucible heater 220 and a cooling jacket 230 , The crucible 210 is for holding solid or liquid evaporating material 2 set up. The heating system 220 may be configured as electrical resistance heating and / or as electron beam heating, as known from conventional evaporator cells. The cooling jacket 230 is for passive or active cooling and to shield the environment of the crucible 210 and the heater 220 set against radiated heat.

On actuation of the heater 220 becomes the evaporation material 2 heated until it is converted by vaporization or sublimation in the vapor state and through the mouth opening 211 of the crucible 210 exits to the outside. The movement of the vaporous vaporized material as a jet of steam 1 (in 1 shown schematically, see also 3 ) follows a predetermined beam direction 3 , where by the geometry of the crucible 210 and the mutual collisions of the atoms or molecules in the jet of steam 1 a certain evaporator characteristic (space in which the evaporated material flows) is formed.

The closure device 100 is relative to the evaporator cell 200 movably arranged and in an open position (in 1 shown) or in a locked position (in 2 shown) can be positioned. In the opening position is the flow chamber 20 in the beam direction 3 over the mouth opening 211 of the crucible 210 so that the steam jet 1 the Verdampfungsguts through the inlet opening 21 at the bottom of the closure device 100 into the flow chamber 20 enter and at the exit opening 22 the flow chamber 20 in the direction of the substrate (not shown) can leave. In the opening position become parts of the steam jet 1 , which form lateral areas of the evaporator characteristic, from the side walls 12.2 . 12.3 and the inside of the cover plate 11 in the vicinity of the outlet 22 collected. 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 directed to the substrate and unwanted precipitation in the environment of the evaporator cell and the substrate in 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 is the closure device 100 arranged so that the collection chamber 10 over the mouth opening 211 of the crucible 210 is positioned. One from the crucible 210 exiting steam jet 1 gets completely from the collection chamber 10 added. The evaporation material is on the insides of the collection chamber 10 ie on the side walls 12.1 . 12.2 and the cover plate 11 deposited, so that an undesirable precipitation in the vicinity of the evaporator cell or other parts of the coating system is avoided.

The closure device 100 is made of a metal or ceramic material. Any material which has sufficient temperature stability and in particular at the operating temperature of the closure device can be used 100 shows neither a geometric deformation nor a release of impurities. For high-temperature evaporator cells whose operating temperature z. B. 2000 ° C, there is the closure device 100 preferably made of tantalum or tungsten sheet metal. For evaporator cells with lower operating temperatures, such. As evaporator cells for organic materials, the closure device 100 be made of steel or glass.

The dimensioning of the closure device 100 may be selected depending on the conditions of the concrete application of the invention. For example, the collecting opening 13 or the inlet opening 21 so dimensioned that it out of the mouth opening 211 of the crucible 210 can completely absorb the exiting steam jet. The length of the side walls 12.1 . 12.2 and 12.3 ie the height of the closure device 100 in the beam direction 3 is chosen so that on the inside of the cover plate 11 in the collection chamber 10 occurring back reflection of heat radiation the temperature in the crucible 210 negligible or negligible influence. The side walls 12.1 and 12.3 are thicker than the sidewall 12.2 and Z. B. hollow. In a concrete example, the closure device 100 for an evaporator cell 200 with a diameter of the mouth opening 211 from 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 6 cm, distance of the bottom of the sidewall arrangement 12 from the evaporator cell 200 : 5 mm.

2 illustrates a closure device 100 in schematic perspective view. The closure device 100 has the box shape described above, through the side walls 12.1 . 12.3 . 12.4 and 12.5 and the cover plate 11 formed and inside by another side wall ( 12.2 in 1 ) in the collection chamber 10 and the flow chamber 20 is divided. 2 illustrates the blocking position in which the collection chamber 10 over the mouth opening 211 of the crucible 210 the evaporator cell 200 is located so that leaking, vaporous vaporization in the collection chamber 10 is caught.

The in the 1 and 2 illustrated closure device 100 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 extending over the entire top of the closure device 100 extends and with flat 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 closure device are described below with reference to the 3 . 5 and 6 to 11 described.

3 illustrates the flow chamber 20 a further embodiment of the closure device according to the invention 100 in a schematic sectional view (perpendicular to the longitudinal extent of the closure device). The flow chamber 20 is through the sidewalls 12.4 . 12.5 , the cover plate 11 and additionally by a bottom plate 14 limited. The bottom plate 14 is at the bottom, ie at the evaporator cell 200 facing side of the closure device 100 provided and with the inlet opening 21 fitted. In the opening position of the closure device 100 are the entrance opening 21 in the bottom plate 14 and the exit opening 22 in the cover plate 11 so arranged that evaporation material 2 as a steam jet 1 from the crucible 210 the evaporator cell 200 with the given beam direction 3 through the flow chamber 20 can pass through. The entrance opening 21 and the exit opening 22 are z. B. circular.

The bottom plate 14 has a double function. First, the entrance opening 21 the flow chamber provided with a predetermined diameter. Furthermore, it can be on the inside of the bottom plate 14 Attach material, the z. B. after a multiple reflection in the flow chamber 20 is deposited or from a deposition 4 on the inside of the cover plate 11 falls. Such collected material is exemplified by the reference numeral 5 illustrated. The bottom plate 14 can delineate the bottom of the closure device 100 only at the flow chamber 20 or both chambers 10 . 20 (please refer 8th . 9 ) or exclusively at the collection chamber 10 be provided.

The embodiment according to 3 is particularly suitable for the evaporation of sublimating evaporating material or high melting point evaporating material. Instead of a parasitic coating of parts of the coating system outside the evaporator cell is provided with the closure device according to the invention 100 the vaporized material during evaporation inside the flow chamber 20 collected. The vaporized material strikes in solid form on the inner sides of the flow chamber 20 low. To maximize the life of the closure device 100 Between two maintenance operations, the internal volume of the flow chamber becomes 20 (and accordingly also the collection chamber 10 ) is maximized depending on the specific conditions of use. Thus, in particular in the flow chamber shown 20 knock down a lot of evaporative material, with the inlet and outlet openings 21 . 22 not or only negligibly reduced.

In 3 is the formation of an evaporative material deposition 4 on the inside of the cover plate 11 schematically illustrated in a concrete example. The dimensioning of the inlet and outlet openings 21 . 22 is based on the following considerations. According to the angle of radiation from the crucible 210 and the expansion of the vapor 2 in the crucible 210 (Flatness of the source), the inlet opening is dimensioned so that no Evampfungsgut on the bottom of the closure device 100 can knock down. Furthermore, the deposition 4 at the edge of the outlet 22 at an oblique angle to the mute of the flow chamber 20 grow up. This growth is in the sizing of the outlet 22 considered. From the capacity of the flow chamber 20 and the resulting service life may be a thickness of the occupancy of the inside of the cover plate 11 in the beam direction 3 be determined. From the emission angle and the thickness of the assignment results in an estimate, which diameter the outlet opening 22 must have to ensure even at the end of a vaporization cycle, a complete deposition of the evaporation material on the substrate.

In this estimation, the contribution of indirect emission of vaporization material from the front insides of the crucible 210 neglected, since experience shows that this is negligibly small in comparison to the contribution of the direct emission of the vaporized material 2 , This is in 4 using the example of a simulation of the flow of evaporating material 1 illustrated. The graph in 4 shows the deposition of the vaporized material on a flat, perpendicular to the crucible axis arranged substrate 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 middle area a, from which the entire surface of the vaporization in the evaporator cell 200 is visible, the coating rate is approximately uniform, so that a uniform deposition or layer thickness is achieved. In the adjoining inner edge region b, from which a part of the surface of the vaporization in the evaporator cell 200 is visible, the coating rate drops sharply and approximately linearly. In the adjoining outer edge region c meets only indirectly from the walls of the crucible 210 emitted material on the substrate. In this range, the coating rate in relation to the inner region is negligible.

The flow chamber 20 a further embodiment of the closure device according to the invention 100 is a schematic sectional view (along the longitudinal direction of the closure device) in 5 illustrated. The flow chamber 20 will, as in 3 through the side walls 12.4 . 12.5 , the bottom plate 14 with the entrance opening 21 and the cover plate 11 with the outlet 22 limited. In addition is at the entrance opening 21 a retaining ring (collar) 15 provided with the on the inside of the bottom plate 14 a reservoir 14.1 for collected vaporization 6 is created. This embodiment of the invention is particularly well suited for the vaporization of liquid vapor.

During operation of the evaporator cell 200 can evaporate on the inside of the flow chamber 20 knock down. Liquid evaporation material runs in at the sidewalls 12.4 . 12.5 down to the bottom plate 14 , In the reservoir 14.1 between the retaining ring 15 and the lower sections of the side walls 12.4 . 12.5 can the liquid evaporate 6 collect. The height of the retaining ring 15 In the beam direction is dependent on the specific conditions of use, in particular as a function of the volume of the liquid Verdampfungsguts 6 that is in the flow chamber 20 is to be withheld. Additionally, when dimensioning the height of the retaining ring 15 be taken into account that during the movement of the closure device 100 an overflow of liquid vapor 6 over the retaining ring 15 is avoided by a wave formation.

The to the middle of the entrance opening 21 facing side of the retaining ring 15 is relative to beam direction 3 inclined with an opening angle α. The opening angle α is dimensioned so that the retaining ring 15 is not hit by evaporative material from the side, which is the symmetry axis of the crucible 210 is facing. The opening angle α is z. B. 20 °.

6 illustrates that the bottom plate 14 with the retaining ring 15 also in the area of the collection chamber 10 can be provided. Accordingly, the collection chamber 10 at the in 6 shown sectional view (transverse to the longitudinal direction of the closure device 100 ) through the side walls 12.4 . 12.5 , the closed cover plate 11 and the bottom plate 14 with the collecting opening 13 limited. Through the retaining ring 15 becomes a reservoir 14.1 on the inside of the bottom plate 14 for receiving the liquid vaporization 6 created. To ensure a directional movement of liquid vapor to this reservoir, is the collection chamber 10 additionally with a drip tray 16 fitted.

The dripping device 16 is adapted to the cover plate 11 to pass collected vaporized material to the bottom plate. Alternatively, the function of the drip 16 be, evaporation to the collection opening 13 to lead (see 7 ). Alternatively or additionally, the dripping device 16 also in the flow chamber 20 be provided (see 9 ).

In the variant according to 6 is to form the drip 16 the inside of the cover plate 11 arranged inclined. Material deposited on this inner side is directed under the action of gravity up to a drip edge 16.1 located above the reservoir on the inside of the bottom plate 14 located. From the drip edge 16.1 can drop 7 the liquid Verdampfungsguts in the reservoir 14.1 fall.

7 illustrates the alternative variant in which the drip 16 is formed so that deposited vaporized material to a drip tip 16.2 above the collecting opening 13 runs and from this in the form of drops 7 in the crucible 210 falls. According to 7 is the drip tray 16 through a conical inside of the cover plate 11 educated. The tip of the conical inside forms the drip tip 16.2 , which is centered over the mouth opening 211 of the crucible 210 is arranged. The variant according to 7 offers advantages, if no value on the highest purity of the evaporating material 2 must be placed and the closure device 100 can be made from a pure inert material with respect to the evaporating, that is, not reacting with the evaporating material. Advantageously, then the material yield of the evaporation almost 100% and the life of the closure device practically unlimited.

The dripping from the drip 16 in the crucible 210 can be provided continuously while the closure device 100 is in the locked position. When the movement of the closure device 100 is provided in the open position, further dripping from the drip tip 16.2 be disturbing. In order to prevent this, at least during the movement or permanently, can each before the movement of the closure device 100 from the blocking to the opening position (or vice versa) a short stepping movement of the closure device 100 be provided with changing direction of movement (short reciprocating movement of the closure device), is initiated by the dripping of the vaporized material targeted.

Since a dripping of liquid evaporating material or a breaking off of solid evaporating material can not be excluded when the collecting chamber 10 in the opening position or the flow chamber 20 in the locking position of the closure device 100 next to the crucible 210 the evaporator cell 200 is located, the evaporator cell 200 additionally with collection containers 220 be equipped. The arrangement of the collection container 220 laterally next to the crucible 210 the evaporator cell is in 8th schematically illustrated. The distance of the collection container 220 from the crucible 210 is equal to the distance between the collecting and inlet openings 13 . 21 the collection and flow chambers 10 . 20 , Notwithstanding the illustrated variant, only a collection container 220 on the side of the crucible 210 be provided, at which the collection chamber 10 in the opening position of the closure device 100 located (in 8th illustrated). Furthermore, it is preferably provided that the collecting container 220 be 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, at least one of the collection and flow chambers 10 . 20 with a guide 17 be fitted, which is adapted to at the bottom plate 14 deposited vaporized material to the collecting opening 13 the collection chamber 10 and / or the inlet opening 21 the flow chamber 20 to lead. In 9 By way of example, a variant is shown in which both chambers 10 . 20 each with a guide 17 are equipped. To form the guide 17 is the inside of the bottom plate 14 around the collecting and inlet openings 13 . 21 each formed funnel-shaped. Thus, liquid evaporating material from the guide 17 drain and in the crucible 210 of the evaporator cell 200 be caught. In addition, at the bottom of the respective opening a cylindrical or funnel-shaped drip edge 17.1 be provided, the example of the guide 17 the flow chamber 20 in 9 is shown. The drip edge 17.1 prevents bleeding of the vaporized material along the bottom of the closure device 100 ,

Because the collecting opening 13 and the entrance opening 21 typically a larger diameter than the mouth opening 211 of the crucible 210 have, is the drip edge 17.1 at the bottom plate 14 outside an extension of the inner walls of the crucible 210 (please refer 212 in 9 ). Nevertheless, a safe absorption of vaporization in the crucible 210 to ensure is the crucible 210 at its mouth opening with a marginal broadening 213 fitted. The edge broadening 213 includes a portion of the crucible 210 in which the diameter of the crucible is towards the mouth opening 211 extended. It is Z. B. a funnel-shaped from the axis of symmetry of the crucible 210 expanding edge area provided. The edge broadening 213 is preferably additionally heated to drain liquid vaporized material in the crucible 210 to facilitate. This is in the vicinity of the mouth opening in the edge broadening 213 a heating device 214 intended.

The closure device according to the invention 100 is particularly suitable for controlling the flow of gaseous vapor. When the collection chamber 10 with a pumping device 40 gaseous evaporating material in the blocking position by the collecting chamber 10 be pumped out. This embodiment of the invention, which in a schematic perspective view in 10 is illustrated, has the particular advantage that a large flow ratio between the open and lock positions can be realized, since the gaseous evaporant in the locked position of the closure device 100 can be effectively pumped out of the coating system.

The closure device 100 includes the collection chamber 10 and the flow chamber 20 that has a coupling element 30 with a drive device 50 (shown schematically) are connected in the coating system. The flow chamber 20 is located at the free end of the closure device 100 while the collection chamber 10 with the coupling element 30 connected is. The coupling element 30 includes a hollow conduit extending from the collection chamber 10 to the pumping device 40 extends. The pumping device 40 includes z. B. a connected to the coating system vacuum pump 41 , The drive device 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 vaporized material is not from a crucible, but by means of a nozzle 215 provided in the coating system. In the collection chamber 10 there is a baffle 18 , with which the gaseous evaporating material, in the blocking position shown by the nozzle 215 through the collecting opening 13 in the collection chamber 10 enters, towards the coupling element 30 is diverted. The baffle 18 includes z. B. a plane, inclined positioned or a quarter circle curved surface that redirects the gas flow. In the opening position, the gaseous evaporating material flows through the inlet and outlet openings 21 . 22 , the flow chamber 20 to the substrate. Deviating from the illustration in 10 may alternatively or additionally consist of a connection of the flow chamber with the coupling element. Advantageously, this makes it possible to also feed evaporated material within the flow chamber to the pumping device.

11 illustrates another embodiment of the closure device according to the invention 100 in addition to the collection chamber 10 and the flow chamber 20 a funnel chamber 60 is provided. In this embodiment of the invention, the closure device fulfills 100 In addition, the function of filling the evaporator cell 200 with solid or liquid evaporating material. The funnel chamber 60 is to the collection or flow chamber 20 arranged adjacent and with an inner, funnel-shaped surface 61 educated. The closure device 100 can be placed in a filling position (in 11 shown), in which the funnel chamber 60 above the evaporator cell 200 located. In the filling position, the evaporator cell 200 be filled by evaporating from a refill (not shown) on top of the closure device 100 in a funnel opening 62 is given. Through the funnel-shaped surface 61 in the funnel chamber 10 the evaporation material is centered with high accuracy in the crucible 210 the evaporator cell 200 brought in.

Advantageously, the funnel chamber allows 60 in that evaporating material can be replenished under vacuum without particularly high demands being placed on the precision of the setting of the refilling device. Due to the funnel shape results in a high tolerance against when dumping possibly laterally evasive Evaporation.

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

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

It is emphasized that 12 the coating system 300 and their components only schematically illustrated. In a specific embodiment, the coating system 300 Equipped with other system parts, as is known from conventional coating technology, such. B. with sensors, manipulators. The coating system 300 includes, for example, an MBE plant.

For operation of the coating system 300 become the evaporator cells 200 loaded with evaporating material and the substrate 8th at the substrate holder 320 fixed. In the vacuum chamber 310 is a reduced operating pressure, z. B. Ultra high vacuum. The evaporator cells 200 are heated, so that evaporating material is in each case transferred to the gaseous state. During heating, the closing devices are located 100 in the blocking position, that is, any escaping vaporized material is in the collection chambers of the closure devices 100 collected. Subsequently, the closure devices 100 collectively, in groups or individually, sequentially moved to multiple or single evaporator cells 200 release. The locking devices 100 are moved to the opening position, so that the steam jet to the substrate 8th flow and evaporate on the substrate 8th can be deposited. If, for example, it is determined by a visual observation, a sensor or the monitoring of other operating parameters that one of the closure devices 100 is completely laden with parasitic deposited evaporate, the relevant evaporator cell 200 off. When the evaporator cell 200 is cooled and no further Evampfungsgut exits, the closure device 100 from the drive device 50 uncoupled and with a manipulation tool (not shown) through the lock 342 into the external environment of the vacuum chamber 310 transferred. After a regeneration of the closure device 100 (Removal of the parasitically deposited vaporization), the closure device 100 again in the coating plant 300 be used.

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 (14)

Closure device ( 100 ) for an evaporator cell ( 200 ), comprising: - a cover plate ( 11 ) relative to the evaporator cell ( 200 ) is movable and arranged in a blocking position for one of the evaporator cell ( 200 ) exiting steam jet ( 1 ) to form a barrier and in an open position the steam jet ( 1 ), and - a sidewall arrangement ( 12 ), which is set up, an environment of the evaporator cell ( 200 ) laterally to the steam jet ( 1 ) and includes side walls extending in a direction different from the extension of the cover plate (FIG. 11 ), wherein - the side wall arrangement ( 12 ) with the cover plate ( 11 ), so that a collection chamber ( 10 ) formed 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 set up that in the blocking position the steam jet ( 1 ) through the collecting opening ( 13 ) into the collection chamber ( 10 ), characterized in that - the sidewall arrangement ( 12 ) so also with the cover plate ( 11 ), that a flow chamber ( 20 ) formed by the cover plate ( 11 ) and side walls ( 12.2 . 12.3 ) of the sidewall arrangement ( 12 ), wherein - the flow chamber ( 20 ) at the bottom of the closure device ( 100 ) at an entrance opening ( 21 ) and at the top of the closure device ( 100 ) at an exit opening ( 22 ) of the cover plate ( 11 ) is open and is set up that - in the open position the steam jet ( 1 ) through the inlet and outlet openings ( 22 ) passes through. Closure device according to claim 1, in which - the closure device ( 100 ) on an underside of the side wall assembly ( 12 ) with a bottom plate ( 14 ) is connected, in the at least one of the collecting opening ( 13 ) and the inlet opening ( 21 ) are formed. Closure device according to claim 2, wherein - the bottom plate ( 14 ) at least one of the collecting opening ( 13 ) and the inlet opening ( 21 ) with a retaining ring ( 15 ), each of which the collecting opening ( 13 ) or the entrance opening ( 21 ) surrounds. Locking device according to one of the preceding claims, in which - the cover plate ( 11 ) in at least one of the collection chamber ( 10 ) and the flow chamber ( 20 ) with a draining device ( 16 ), which is arranged on the cover plate ( 11 ) collected vaporized material to the collecting opening ( 13 ), to the bottom plate ( 14 ) or to the entrance opening ( 21 ). Locking device according to one of claims 2 to 4, in which - the bottom plate ( 14 ) in at least one of the collection chamber ( 10 ) and the flow chamber ( 20 ) with a guide ( 17 ), which is arranged on the bottom plate ( 14 ) collected vaporized material to the collecting opening ( 13 ) or to the entrance opening ( 21 ). Locking device according to one of the preceding claims, in which - at least one of the collecting chamber ( 10 ) and the flow chamber ( 20 ) with a pumping device ( 40 ) connected is. Closure device according to one of the preceding claims, comprising - a coupling element ( 30 ), which for releasably fixing the closure device ( 100 ) in a coating plant ( 300 ) is set up. Closure device according to one of the preceding claims, comprising - a funnel chamber ( 60 ), which in a filling position of the closure device for introducing evaporating material ( 2 ) in the evaporator cell ( 200 ) is set up. Evaporator cell ( 200 ), comprising: - a crucible ( 210 ) for the absorption of evaporating material ( 2 ), and - a closure device ( 100 ) according to one of the preceding claims. An evaporator cell according to claim 9, wherein - the crucible ( 210 ) at a mouth opening ( 211 ) an edge broadening ( 213 ), at which the diameter of the crucible ( 210 ) widened funnel-shaped. Coating plant ( 300 ), comprising: - at least one evaporator cell ( 200 ) provided with a closure device ( 100 ) is equipped according to one of claims 1 to 8. 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. Method for operating a coating installation ( 300 ) with at least one evaporator cell ( 200 ), the closure device ( 100 ) according to one of claims 1 to 8, 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 ), and - an operating phase in which the closure device ( 100 ) is arranged in the open position, so that the steam jet ( 1 ) of the vaporization product from the evaporator cell ( 200 ) on a substrate ( 8th ) and the evaporation material on the substrate ( 8th ). Use of a closure device ( 100 ) according to one of claims 1 to 8 during operation of a coating installation ( 300 ).

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