Apparatus and method for cleaning cup-shaped hollow bodies, in particular transport containers for semiconductor wafers or for EUV lithography masks

Abstract

The present invention relates to an apparatus (92) for cleaning cup-shaped hollow bodies (94), the apparatus (92) comprising: a contact wall (20), onto which the hollow body (94) can be seated; at least one through-opening (24), which is formed by the contact wall (20); a cleaning device (40), by means of which a cleaning fluid can be discharged to clean the cover contact surface (96) when the hollow body (94) is seated on the contact wall (20), the cleaning device (40) comprising a cleaning head (42), which protrudes over the through-opening (24) when the hollow body (94) is seated on the contact wall (20), and a number of cleaning nozzles (100), by means of which the cleaning fluid can be applied to the cover contact surface (96). The invention also relates to a method for cleaning cup-shaped hollow bodies (94) by means of an apparatus (92) of this type.

Description

[0001] Device and method for cleaning pot-shaped hollow bodies, in particular transport containers for semiconductor wafers or for EUV lithography masks

[0002] The present invention relates to a device for cleaning pot-shaped hollow bodies, in particular transport containers for semiconductor wafers or for EUV lithography masks.

[0003] The production of highly integrated electronic circuits and other sensitive semiconductor components takes place today in factories where semiconductor wafers undergo numerous processing steps. A large portion of these processing steps takes place in clean rooms, which are kept free of contaminants, especially particles, at great expense. Such complex processing is necessary because particles that come into contact with the semiconductor material of the semiconductor wafers can influence the material properties of the semiconductor wafers to such an extent that an entire production batch becomes defective and unusable and must be rejected.

[0004] Since cleanliness becomes more and more important with the increasing integration density of semiconductor circuits and the effort required for cleanliness increases exponentially with the size of cleanrooms, the semiconductor wafers are not transported "openly" from one processing station to the next. Instead, special transport containers (so-called FOUPs, Front Opening Unified Pods) are used. These are box-shaped transport containers into which a large number of semiconductor wafers are inserted. The FOUPs are usually closed with a removable lid. Without the lid, the FOUPs have a pot-shaped basic shape with a rectangular base. When the FOUPs are closed with their lid, the inserted semiconductor wafers can be transported from one cleanroom to another, protected from the environment.Once the FOUPs reach a processing station, they are opened, the semiconductor wafers are removed, and processed accordingly. After processing, the semiconductor wafers are transported back to the FOUPs and then forwarded to the next processing station.

[0005] Due to the high production downtime caused by contamination of semiconductor wafers, it is necessary to clean the FOUPs from time to time. The FOUPs are particularly contaminated by abrasion of the semiconductor wafers during insertion into and removal from the FOUPs.

[0006] The same applies to transport containers for EUV lithography masks ("extreme ultraviolet radiation"). EUV lithography masks are used to manufacture very small integrated circuits. Like semiconductors, EUV lithography masks also need to be transported, which creates a similar situation. When reference is made to FOUPs in the following, the relevant statements apply equally to transport containers for EUV lithography masks.

[0007] Devices for cleaning FOUPs are known, for example, from WO 2006 / 136224 A1, WO 2005 / 001888 A2 and DE 10 2020 129 469 A1. With devices of this type, the FOUPs can be cleaned on both their inner and outer surfaces. As mentioned, the FOUPs are closed with a lid which is only removed when the semiconductor wafers are introduced into or removed from the FOUPs. The outer surface of the FOUPs is usually significantly more contaminated than the inner surface. The lid support surface plays a special role in this case. For example, in the case of the FOUPs shown in DE 10 2020 129 469 A1, the lid support surface is located between the inner and outer surfaces. However, in more modern FOUPs, the lid support surface is formed by a shoulder of the inner surface, so that the lid is positioned by the inner surface when the lid is placed on the lid support surface.Due to contact with the lid, contaminants originating from the lid accumulate on the lid support surface. As a result, the lid support surface is more contaminated than the rest of the interior surface. However, contaminants located on the interior surface can be deposited directly on the semiconductor wafers and produce the effects described above.

[0008] The object of one embodiment of the present invention is to provide a device for cleaning a pot-shaped hollow body, with which it is possible to remedy the above-mentioned disadvantages using simple and cost-effective means and, in particular, to reduce the number of defective and unusable production batches of semiconductor wafers. Furthermore, one embodiment of the present invention is based on the object of creating a method with which such a device can be operated.

[0009] This object is achieved by the features specified in claims 1 and 11. Advantageous embodiments are the subject of the dependent claims.

[0010] One embodiment of the invention relates to a device for cleaning pot-shaped hollow bodies, in particular transport containers for semiconductor wafers or for EUV

[0011] Lithography masks, where the hollow body

[0012] - a bottom wall and one or more side walls forming a hollow body inner surface,

[0013] - an opening opposite the bottom wall, which is enclosed by the side wall, and

[0014] - and a lid support surface formed by the side wall, onto which a lid can be placed to close the hollow body, wherein the device

[0015] - a support wall on which the hollow body can be placed,

[0016] - at least one passage opening formed by the support wall, and

[0017] - a cleaning device with which a cleaning fluid can be dispensed to clean the lid support surface when the hollow body is placed on the support wall (20), wherein

[0018] - the cleaning device has a cleaning head which o projects beyond the through-opening when the hollow body is placed on the support wall, and o has a number of cleaning nozzles through which the cleaning fluid can be applied to the cover support surface.

[0019] The hollow body is placed with a support surface on the support wall and, if necessary, locked so that the hollow body is fixed in its position relative to the support wall. It should be noted at this point that the support wall does not correspond to the lid support surface. Rather, it is assumed below that the lid support surface is part of the hollow body's inner surface and is formed by the side wall of the hollow body.

[0020] Because the cleaning head is equipped with cleaning nozzles specifically designed for cleaning the lid support surfaces, it is possible to clean the lid support surfaces very thoroughly, largely removing contaminants that may accumulate on the semiconductor wafers. As a result, the number of defective and unusable production batches of semiconductor wafers can be significantly reduced compared to state-of-the-art devices.

[0021] According to a further embodiment, the cleaning head can have a number of drying nozzles with which a drying gas can be applied to the lid support surface. In this embodiment, the proposed device can be used not only for cleaning, but also for the subsequent drying of the hollow body. To conclude the cleaning process, the supply of cleaning fluid is stopped and instead a drying gas, for example air or nitrogen, is conveyed to the drying nozzles, with which the lid support surface is dried. The residues of the cleaning fluid still remaining on the lid support surface are removed with the drying gas.

[0022] In a further developed embodiment, the cleaning head can be movable in a rotational and / or translational manner. Due to the mobility of the cleaning head, it is possible to respond to geometric peculiarities of the lid support surface. In particular, it is possible to apply the first cleaning fluid at least approximately perpendicularly to the lid support surface, whereby the kinetic energy of the cleaning fluid can be used particularly effectively to clean the lid support surface.

[0023] In a further developed embodiment, the cleaning fluid and / or the drying gas can be delivered at a spray angle, wherein the cleaning head has an adjustment device which interacts with the cleaning nozzles and / or with the drying nozzles and with which the spray angle can be adjusted. The spray angle at which the first cleaning fluid is delivered also determines the angle at which the cleaning fluid hits the lid support surface. An angle of 90° or approximately 90° is ideal. Due to the fact that the spray angle is adjustable, the geometry of the hollow body's inner surface can be simulated in such a way that the first cleaning fluid can be applied to the lid support surface and adjacent areas of the hollow body's inner surface at an angle of 90° or approximately 90°.The hollow body's inner surface typically has angled sections, so that non-adjustable cleaning nozzles can lead to shadowing, in which no or only a limited amount of cleaning fluid can be applied with sufficient kinetic energy to the hollow body's inner surface, and in particular to the lid support surface and adjacent areas. Such shadowing can be avoided in this embodiment, thus improving the overall cleaning result.

[0024] In a further embodiment, the cleaning head can have a number of infrared diodes with which the lid support surface can be heated. The infrared diodes can heat the lid support surfaces, thereby assisting the drying process, which is carried out using the drying gas. Any residues of the cleaning fluid remaining on the lid support surface are removed as a result of the heating.

[0025] A further developed embodiment can be characterized in that the cleaning head has an external shape which at least approximately follows the course of the inner surface of the hollow body, so that the distance between the inner surface of the hollow body and the cleaning head is constant or almost constant. It has been found that a distance of between 1 mm and 50 mm and in particular between 10 mm and 30 mm is ideal for a good cleaning result. A small distance helps to create a strong, directed flow in the space between the inner surface of the hollow body and the cleaning head, which results in a particularly good cleaning and drying effect. The distance does not have to be the same across the entire space, but can also vary, which is advantageous, for example, if the side wall forms projections, depressions and / or undercuts.In this case, it may be preferable for the cleaning head to be designed largely to complement the contour of the hollow body's inner surface, so that its outer shape does not follow individual projections and / or recesses in the side wall. In these cases, the cleaning head can be inserted into the interior more easily and quickly without negatively affecting the cleaning and / or drying effect.

[0026] According to a further embodiment, the device can have at least one coupling unit for coupling sound waves into the cleaning fluid. The sound waves can be designed in particular as ultrasonic waves or as megasonic waves. While ultrasonic waves, depending on the definition, have a frequency range of approximately 20 kHz to 500 kHz, megasonic waves have a frequency range of approximately 500 kHz to 3 MHz. In this case, it is advisable to completely wet the inner surface of the hollow body with the cleaning fluid or to flood the space between the cleaning head and the inner surface of the hollow body and to couple the sound waves into the cleaning fluid. The cleaning fluid then serves as a transmitter for the sound waves.Due to the fact that a certain amount of energy is introduced into the cleaning fluid, the cleaning effect is increased, as particles adhering to the lid contact surface can be removed particularly effectively. The energy input increases with the frequency of the coupled sound. The use of megasound has the advantage that the energy can be delivered very precisely to the lid contact surface to be cleaned, so that good cleaning results can be achieved.

[0027] In a further embodiment, it may be advantageous for at least some of the coupling units to be integrated into at least some of the cleaning nozzles or to interact with them. In this case, the cleaning nozzles can be designed as so-called "megasonic nozzles," which allow the sound waves to be coupled into the first cleaning fluid emitted by the first cleaning nozzles. It is then not necessary to wet the entire inner surface of the hollow body with the first cleaning fluid, which allows the amount of the required first cleaning fluid to be kept low.

[0028] In a further developed embodiment, the device can comprise a discharge channel with a first end, wherein the first discharge channel with the first end is in fluid communication exclusively with the through-opening and with which the cleaning fluid emitted by the cleaning device can be discharged. In this embodiment, the cleaning fluid comes into contact exclusively with the hollow body inner surface. Typically, the hollow body outer surface is more heavily contaminated than the hollow body inner surface, but the influence of the contaminants on the hollow body inner surface on the number of defective and unusable production batches of semiconductor wafers is greater than contaminants on the hollow body outer surface, among other things due to the small spatial distance between the contaminants on the hollow body inner surface and the semiconductor wafers.Since the cleaning fluid in this embodiment can only come into contact with the inner surface of the hollow body, it is not contaminated by impurities on the outer surface of the hollow body. Therefore, the cleaning effect of the cleaning fluid is not reduced.

[0029] In a further embodiment, a particle measuring device for determining the particles contained in the cleaning fluid can be arranged in the discharge channel. As mentioned, the cleaning fluid only comes into contact with the inner surface of the hollow body and consequently also with the lid contact surface. Since the cleaning nozzles are designed to clean the lid contact surface, it can be assumed that the particles registered by the particle measuring device originate only or mostly from the lid contact surface. The particle measuring device can, for example, count the number of particles. If the number falls below a certain threshold value, this can be regarded as a criterion that the hollow body has been sufficiently cleaned. The cleaning process can then be aborted. This can save time and cleaning fluid.According to a further embodiment, the cleaning head can have a number of additional cleaning nozzles for cleaning the hollow body's inner surface. The additional cleaning nozzles can be constructed identically to the cleaning nozzles used to clean the lid support surface. However, they are arranged on the cleaning head in such a way that the cleaning fluid they discharge does not impinge on the lid support surface. The additional cleaning nozzles can be used to clean the remaining hollow body's inner surface, further reducing the number of defective and unusable production batches of semiconductor wafers.

[0030] In a further embodiment, the cleaning head can comprise a flexible sleeve which can be converted from a contracted state to an expanded state and back again using the cleaning fluid and / or the drying gas. The cleaning nozzles, the drying nozzles and / or the further cleaning nozzles can be designed as simple holes or perforations in the flexible sleeve. Alternatively, the sleeve can be designed as a membrane. This ensures that the cleaning fluid and / or the drying gas introduced into the sleeve can escape from the cleaning head and onto the lid support surface and / or the inner surface of the hollow body.The flexible sleeve is designed in such a way that when the cleaning fluid and / or the drying gas is introduced into the flexible sleeve a certain flow resistance arises which must first be overcome so that the cleaning fluid and / or the drying gas can leave the sleeve again through the holes or perforations. This flow resistance leads to an accumulation of the cleaning fluid or the drying gas in the sleeve, as a result of which the sleeve is converted from the contracted state into the expanded state. The dimensions of the sleeve in the expanded state can be changed within certain limits by changing the pressure with which the cleaning fluid and / or the drying gas is introduced into the sleeve. In this respect the distance between the inner surface of the hollow body and the cleaning head can be adjusted and adapted to hollow bodies of different shapes.

[0031] One embodiment of the invention relates to a method for cleaning pot-shaped hollow bodies, in particular transport containers for semiconductor wafers or for EUV lithography masks, with a device according to one of the preceding claims, comprising the following steps:

[0032] - Placing the hollow body on the support wall,

[0033] - Dispensing a cleaning fluid for cleaning the lid support surface by means of a number of cleaning nozzles arranged on the cleaning head of the cleaning device in such a way that the cleaning fluid is applied to the lid support surface, and

[0034] - Discharge of the cleaning fluid via the discharge channel.

[0035] The technical effects and advantages that can be achieved with the proposed method correspond to those discussed for the present device. In summary, it should be noted that the lid support surface can be cleaned in a targeted manner. As mentioned, the lid support surface has a significant influence on the number of defective and unusable production batches of semiconductor wafers. Due to the targeted cleaning of the lid support surface, this number can be significantly reduced compared to methods known from the prior art.

[0036] In a further embodiment, the method may comprise the following steps: - Determining the particles contained in the cleaning fluid by means of the particle measuring device arranged in the discharge channel, and

[0037] - Stop dispensing the cleaning fluid when a particle-related threshold value is exceeded or not reached.

[0038] The particle measuring device can, for example, determine the number and / or diameter of the particles. Furthermore, a related threshold value can be defined; exceeding or falling below this threshold value can indicate that the hollow body has been sufficiently cleaned and the cleaning process can be terminated. On the one hand, it can be documented that a specific hollow body has indeed been sufficiently cleaned, and on the other hand, the cleaning process can be terminated when the hollow body is sufficiently clean.

[0039] Advanced training may specify that the procedure includes the following steps:

[0040] - Completely flooding the space between the cleaning head and the hollow body inner surface with the cleaning fluid, and

[0041] - Coupling of sound waves into the cleaning fluid by means of a coupling unit.

[0042] The sound waves can be coupled, for example, in the form of ultrasound or megasound. This improves the cleaning result because it introduces energy into the first cleaning fluid, which serves to loosen the particles on the hollow body's inner surface. A further embodiment may specify that the method includes the following steps:

[0043] - Cleaning the lid support surface using the cleaning nozzles, and

[0044] - Time-delayed cleaning of the hollow body inner surface using the additional cleaning nozzles.

[0045] As mentioned, the particles contained in the cleaning fluid can be determined and, for example, counted using the particle measuring device as it flows through the discharge channel. It can be assumed that at least the majority of particles which are generated when the lid support surface is cleaned using the cleaning nozzles originate from the lid support surface. The same applies to the cleaning of the inner surface of the hollow body. Even within the other cleaning nozzles, some can be activated at a time delay to the other cleaning nozzles. This makes it possible to determine whether or not certain areas of the inner surface of the hollow body are more heavily contaminated than other areas, and in particular than the lid support surface. This can be used to determine errors in the production process for the semiconductor wafers.

[0046] Exemplary embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

[0047] Figure 1 is a schematic sectional view through a device according to the prior art for cleaning pot-shaped hollow bodies, in particular transport containers for semiconductor wafers or for EUV lithography masks, Figure 2 is a non-scale enlarged view of the device according to

[0048] Figure 1 defined section A, and

[0049] Figure 3 shows a basic sectional view through an embodiment of a device according to the invention for cleaning pot-shaped hollow bodies, in particular transport containers for semiconductor wafers or for EUV lithography masks,

[0050] Figure 1 shows an exemplary embodiment of a device 10 according to the prior art described, for example, in DE 10 2020 129 469 A1 for cleaning pot-shaped hollow bodies 12 using a basic sectional view. The device 10 has a housing 14 which forms a housing opening 16 which can be closed with a cover 18 which can be removed from the housing 14. In addition, a support wall 20 is arranged in the housing 14 so that a closed process chamber 22 is created in the housing 14. The process chamber 22 is delimited by the support wall 20, the housing 14 itself and the cover 18. The support wall 20 forms a through opening 24, with a locking device 26 being arranged radially outside the through opening 24. In the embodiment shown, two through holes 28 are provided in the support wall 20 radially outside the locking device 26.

[0051] With the cover 18 removed, a hollow body 12, in particular a transport container 30 for semiconductor wafers, also referred to as FOUPs, or a transport container 30 for EUV lithography masks, can be introduced into the process chamber 22. The hollow body 12 has a bottom wall 32 and, in this case, four side walls 34, so that the pot-shaped hollow body 12 is essentially cuboid-shaped. However, it is entirely possible to provide the pot-shaped hollow body 12 with a different geometry, for example a cylindrical one. The bottom wall 32 and the four side walls 34 form an inner surface 33 of the hollow body and an outer surface 35 of the hollow body.

[0052] The hollow body 12 has an opening 36 which is arranged opposite the bottom wall 32 and which is enclosed by an edge surface 38 which is formed by the side walls. In the region of the edge surface 38, the hollow body 12 is designed like a flange in the illustrated embodiment. With this edge surface 38, the hollow body 12 can be placed on the support wall 20. The through-opening 24 of the support wall 20 and the opening 36 of the hollow body 12 are at least approximately of the same size and of the same geometric shape in the illustrated embodiment.

[0053] Furthermore, the locking device 26 is designed such that the through opening 24 is at least approximately aligned with the section of the hollow body inner surface 33 adjoining the through opening 24.

[0054] In Figure 2, the area A marked in Figure 1 is not shown to scale, whereby there is no exact correspondence. For reasons of illustration, the locking device 26 is not shown. It can be seen from Figure 2 that the support wall 20 comprises a support wall section 37 which forms a contact surface 39 which is in contact with the edge surface 38 of the transport container 30. The contact surface 39 of the support wall section 37 is completely covered by the edge surface 38. A first channel 41 is arranged in the support wall section 37, which opens into the contact surface 39 and with which a flushing fluid, for example air or nitrogen, can be guided to the edge surface 38.

[0055] Furthermore, the device 10 is equipped with a cleaning device 40 having a first cleaning head 42 that protrudes beyond the through-opening 24 and is thus arranged within the process chamber 22. When the hollow body 12 is connected to the support wall 20, the first cleaning head 42 is enclosed by the hollow body 12.

[0056] The housing 14 further comprises a wall section 44 in which a cleaning opening 46 is arranged. The wall section 44 is located on the side of the support wall 20 facing away from the locking device 26. The cleaning opening 46 can be at least partially closed with a closure body 48 which is fastened to the wall section 44 by a drive unit (not shown) such that it can rotate about a first axis of rotation D1. The closure body 48 can be moved between an open position, in which the closure body 48 releases the cleaning opening 46, and a closed position in which the closure body 48 at least partially closes the cleaning opening 46. In Figure 1, the closure body 48 is in the closed position.

[0057] The closure body 48 has a receiving unit 50 with which a lid 52, with which the hollow body 12 can be closed, can be detachably fastened to the closure body 48. The lid 52 forms an inner lid surface 54 and an outer lid surface 56. The inner lid surface 54 is the side of the lid 52 which directly adjoins the hollow body inner surface 33 when the hollow body 12 is closed with the lid 52. In other words, the inner lid surface 54 in this case points towards the bottom wall 32 of the hollow body 12.

[0058] In the illustrated embodiment, the receiving unit 50 is designed such that it interacts with the cover 52 only by means of the cover outer surface 56.

[0059] The cleaning device 40 is also equipped with a further first cleaning head 58 which is arranged in the vicinity of the closure body 48 when the latter is in the closed position.

[0060] The cleaning device 40 additionally comprises a second cleaning head 64 which is essentially U-shaped and is arranged at least partially in the process chamber 22. In contrast to the first cleaning head 42, however, the second cleaning head 64 is arranged outside the hollow body 12 when the hollow body 12 is connected to the support wall 20 as shown in Figure 1. The second cleaning head 64 is rotatable about a second axis of rotation D2, although the drive device used for this is not shown. Also not shown is an embodiment in which the second cleaning head 64 is movable not only in rotation but also in translation or only in translation. In the embodiment shown, the first cleaning head 42 is not movable, but it can also be designed to be movable in rotation and / or translation.

[0061] The device 10 is further provided with a fluid guide unit 66, with which a first cleaning fluid can be guided to the first cleaning head 42 and to the further first cleaning head 58, and a second cleaning fluid can be guided to the second cleaning head 64. The fluid guide unit 66 has a first supply channel 68, with which the first cleaning fluid can be guided to the first cleaning head 42.

[0062] For reasons of illustration, a detailed illustration of a second supply channel for supplying the second cleaning fluid to the second cleaning head 64 has been omitted, the design of which should, however, be readily apparent to a person skilled in the art.

[0063] Furthermore, the fluid guide unit 66 comprises a first discharge channel 70, with which the first cleaning fluid discharged by the first cleaning head 42 and by another first cleaning head 58 can be discharged from the process chamber 22. The first discharge channel 70 has a first end 72, which is in fluid communication with the through-opening 24. As can be seen from Figure 1, the first discharge channel 70 widens in a funnel shape towards the first end 72 and is connected to the support wall 20 in such a way that the first end 72 of the discharge channel is flush with the through-opening 24.

[0064] In addition, the fluid guide unit 66 has a second discharge channel 76 which is constructed essentially in the same way as the first discharge channel 70, but is in fluid communication with the two through-bores 28. The first discharge channel 70 forms the radially inner wall of the second discharge channel 76, so that the fluid guide unit 66 can be made very compact. At this point it should be pointed out that the fluid guide unit 66 is only shown in principle in Figure 1. Due to the large number of channels arranged in a nested manner and in different planes, the representation of the fluid guide unit 66 according to Figure 1 makes no claim to correctness. At the same time, a flushing fluid is guided through the first channel 41 to the edge surface 38 and / or through the second channel 57 to the cover 52.This can be the same flushing fluid, but it is also possible to conduct a first flushing fluid through the first channel 41 and a second flushing fluid, different from the first flushing fluid, through the second channel 57. The flushing fluid, which is conducted through the first channel 41 to the edge surface 38, ensures that neither the first cleaning fluid nor the second cleaning fluid can cross the edge surface. The flushing fluid therefore creates a fluidic seal between the first cleaning fluid and the second cleaning fluid. This ensures that the first cleaning fluid and the second cleaning fluid cannot mix. Contamination of the first cleaning fluid with the second cleaning fluid, and vice versa, is prevented. However, it should be pointed out at this point that the flushing fluid has no or only a very limited cleaning effect on the edge surface 38.

[0065] The first cleaning fluid, which has been discharged by the first cleaning head 42 and applied to the hollow body inner surface 33, is discharged via the first discharge channel 70. The same applies to the first cleaning fluid, which has been discharged by the further first cleaning head 58 and applied to the lid inner surface 54. To discharge the first cleaning fluid, which is used to clean the lid inner surface 54, the first discharge channel 70 has a secondary channel 84, which opens into the first discharge channel 70.

[0066] The flushing fluid, which is guided to the cover 52, flows through the gap 60 back into the secondary channel 84. The housing seal 51 prevents the flushing fluid from escaping into the environment. The flushing fluid prevents the first cleaning fluid, which has been discharged by the additional first cleaning head 58 and applied to the inner surface 54 of the cover, from reaching the cover seal 53, to which particles in the first cleaning fluid could adhere.

[0067] The flushing fluid which is supplied to the edge surface 38 and / or to the cover 52 can be placed under a sufficiently high pressure.

[0068] The first cleaning fluid removes particles that were located on the hollow body inner surface 33 and the lid inner surface 54. The second cleaning fluid, which was released by the second cleaning head 64 and applied to the hollow body outer surface 35, is removed via the second removal channel 76. Consequently, the first cleaning fluid and the second cleaning fluid are removed separately from one another, as a result of which particles that originate from the hollow body outer surface 35 cannot get into the first cleaning fluid and thus onto the hollow body inner surface 33 or the lid inner surface 54.

[0069] When the hollow body inner surface 33 and the lid inner surface 54 have been cleaned to the desired extent, the cleaning process can be stopped regardless of the extent to which the hollow body outer surface 35 has been cleaned.

[0070] Now a first drying gas and a second drying gas, for example air or nitrogen, can be fed to the first cleaning head 42, to the further first cleaning head 58 and to the second cleaning head 64 via the first feed channel 68 or a second feed channel (not shown here) in largely the same way as the first and second cleaning fluids. The first cleaning head 42 has first drying nozzles 86, the further first cleaning head 58 has further first drying nozzles 88 and the second cleaning head has second drying nozzles 90, with which the first drying gas and the second drying gas can be released and applied to the hollow body inner surface 33, the lid inner surface 54 and the hollow body outer surface 35. The first drying gas and the second drying gas displace the first cleaning fluid and the second cleaning fluid from the device 10.Residues of the first and second cleaning fluids can also be blown away.

[0071] After the drying process is completed, the cover 18 is opened and the closure body 48 is moved into the open position. The cleaned hollow body 12 is removed from the processing chamber. The receiving unit 50 is deactivated, as a result of which the lid 52 can be removed from the closure body 48 and fed to the hollow body 12 to close it. Another hollow body 12 to be cleaned can now be treated in the device 10 in the manner described.

[0072] Figure 3 shows a first exemplary embodiment of a device 92i for cleaning pot-shaped hollow bodies 94 based on a basic sectional view. The essential structure and the manner in which the proposed device 92i can be operated essentially correspond to those described for the prior art device 10 shown in Figures 1 and 2. Therefore, only the features essential to the invention are shown in Figure 3.

[0073] If one compares the hollow body 12, which can be cleaned with the device 10 shown in Figures 1 and 2, with the hollow body 94, which is to be cleaned with the proposed device 92i, it is found that the latter hollow body 94 has, in addition to the edge surface 38, a lid support surface 96, which is part of the hollow body inner surface 33 and which is formed by means of a shoulder of the side wall 34.

[0074] The cleaning device 40 has a cleaning head 98 which is equipped with a number of cleaning nozzles 100 through which the cleaning fluid can be applied to the lid support surface 96. Furthermore, the cleaning head 98 is equipped with drying nozzles 102 through which a drying gas can be applied to the lid support surface 96. The cleaning nozzles 100 and the drying nozzles 102 can be constructed identically, so that no distinction is made between them in the drawing in Figure 3. The cleaning nozzles 100 can also be designed such that they can be used to apply both the cleaning fluid and the drying gas to the lid support surface 96.

[0075] The cleaning nozzles 100 and / or the drying nozzles 102 interact with an adjustment device 104, with which a spray angle α, at which the cleaning fluid and / or the drying gas are released, can be adjusted. For this purpose, the cleaning nozzles 100 and the drying nozzles 102 can be mounted in a spherical head shape. Alternatively or cumulatively, the cleaning nozzles 100 in particular can be arranged on a tubular body 83 which is rotatable about a third axis of rotation D3, whereby the spray angle α can be adjusted. This makes it possible to ensure that the cleaning fluid and / or the drying gas impinges on the lid support surface 96 perpendicularly or almost perpendicularly. Furthermore, the device 92i has at least one coupling unit 106 for coupling sound waves into the cleaning fluid.In the illustrated embodiment, some of the coupling units 106 are integrated into at least some of the cleaning nozzles 100 and designed as so-called "megasonic nozzles." A megasound can be coupled into the cleaning fluid emitted by the cleaning nozzles 100.

[0076] In addition, further cleaning nozzles 108 are arranged on the cleaning head 98, with which the cleaning fluid can be applied to the hollow body inner surface 33. In the illustrated embodiment, the further cleaning nozzles 108 are constructed identically to the cleaning nozzles 100 with which the lid support surface 96 can be cleaned. In particular, they can also interact with the adjustment device 104, with which the spray angle α can be adjusted (not shown). In addition, further drying nozzles 110 can be provided on the cleaning head 98.

[0077] The cleaning nozzles 100 and the additional cleaning nozzles 100 can be opened and closed independently of one another. Consequently, it is possible to clean different sections of the hollow body's inner surface 33 first and other sections later. For example, sections that are known to be less heavily contaminated can be cleaned first, followed by sections that are known to be more heavily contaminated.

[0078] The cleaning head 98 can be moved translationally and / or rotationally along or around a fourth rotational axis D4 by means of a drive device (not shown). In addition, the cleaning head 98 has a number of infrared

[0079] Diodes 112, with which the lid support surface 96 can be heated. Additional infrared diodes 112 (not shown) can also be arranged on the cleaning head 98 in order to heat the remaining hollow body inner surface 33.

[0080] The cleaning head 98 has an external shape which at least approximately follows the profile of the hollow body inner surface 33, so that the distance A between the hollow body inner surface 33 and the cleaning head 98 is constant or almost constant. The aim is to select the distance A as minimal as possible in order to, on the one hand, generate a strong and clearly directed flow of the cleaning fluid and / or the drying gas in the space between the hollow body inner surface 33 and the cleaning head 98 and, on the other hand, to minimize the volume of the space in order to keep the volume of cleaning fluid and drying gas required correspondingly low. In the exemplary embodiment shown, the distance A should be between 10 mm and 30 mm. The space is designed in the manner of an annular gap.

[0081] Furthermore, a particle measuring device 114 for determining the particles contained in the cleaning fluid is arranged in the first discharge channel 70.

[0082] As mentioned, the device 92i according to the invention can be operated essentially in the same way as that from the prior art which has been described in Figures 1 and 2. However, it should be noted that the lid support surface 96 can be cleaned at a time offset from the remaining hollow body inner surface 33. If the lid support surface 96 is cleaned, it can be assumed that the particles present in the cleaning fluid as it flows through the first discharge channel 70 originate from the lid support surface 96. The particles can be characterized with the particle measuring device 114 with regard to a relevant parameter, for example with regard to the number of particles. As soon as a threshold value of the number of particles is undershot in relation to a unit of time, the supply of cleaning fluid to the lid support surface 96 can be interrupted.The remaining inner surface 33 of the hollow body can now be cleaned using the additional cleaning nozzles 108. Here, too, the supply of cleaning fluid can be stopped if, for example, the number of particles in the cleaning fluid falls below a certain threshold value when flowing through the first discharge channel 70. Both when cleaning the lid support surface 96 and the inner surface 33 of the hollow body, the cleaning head 98 can be rotated about a fourth axis of rotation D4 and moved along this axis. In addition, the spray angle α can be changed using the adjusting device 104, and sound waves can be coupled into the cleaning fluid using the coupling unit 106.

[0083] A drying gas can then be applied to the lid support surface 96 using the drying nozzles 102. The lid support surface 96 can be heated simultaneously or with a time delay using the infrared diodes 112. In this case, too, the cleaning head 98 can be rotated about the fourth axis of rotation D4. After the hollow body 94 has been sufficiently dried, another hollow body 94 to be cleaned can be treated in the device 92i in the manner described. It should be noted at this point that the hollow body outer surface 35 and the lid 52 (not shown in Figure 3) can be treated in an essentially analogous manner.

[0084] Figures 4A and 4B show a proposed second exemplary embodiment of a device 922 for cleaning pot-shaped hollow bodies 94 using a basic sectional view. The essential difference from the exemplary embodiment of the device 92i shown in Figure 3 is that the cleaning head 98 has a flexible sleeve 116 which can be converted from a contracted state (Figure 4A) into an expanded state (Figure 4B) and back again. Starting from the contracted state shown in Figure 4A, the cleaning fluid or the drying gas is introduced into the flexible sleeve 116 through the feed channel 68. As a result, the flexible sleeve 116 fills with the cleaning fluid or the drying gas and continues to expand.The flexible sleeve 116 expands until the volume of the supplied cleaning fluid or drying gas is equal to the volume which leaves the flexible sleeve 116 through the cleaning nozzles 100, drying nozzles 102 and / or further cleaning nozzles 108. For reasons of illustration, the cleaning nozzles 100, drying nozzles 102 and / or further cleaning nozzles 108 are only shown in Figure 4B. The flexible sleeve 116 is then in the expanded state. The dimensions of the flexible sleeve 116 in the expanded state can be selected within certain limits with the cleaning fluid or drying gas used as well as with the temperature and the pressure under which the cleaning fluid or the drying gas is introduced into the flexible sleeve 116.Since the cleaning fluid and the drying gas flow in the space between the hollow body inner surface 33 and the cleaning head 98 along the hollow body inner surface 33, the flexible sleeve 116 is prevented from coming into contact with the hollow body inner surface 33. In this respect, the flexible sleeve 116 can adapt within certain limits to the shape of the hollow body inner surface 33, particularly in areas of undercuts, so that a constant or almost constant distance A is obtained, which can be minimized to a very large extent, something that is only possible to a limited extent with a rigid cleaning head 98. As mentioned, the distance A with a rigid cleaning head 98 is between 10 mm and 30 mm. This distance A can be further reduced with a flexible sleeve 116.As mentioned, with a small distance A, a strong and clearly directed flow of the cleaning fluid and / or the drying gas can be generated in the space between the hollow body inner surface 33 and the cleaning head 98 and the volume of cleaning fluid and drying gas required can be kept low. These advantages can be realized to an even greater extent by using a flexible sleeve 116. As also mentioned, the flexible sleeve 116 can adapt within certain limits to the shape of the hollow body inner surface 33. As a result, it is also possible to use the device for cleaning and / or drying differently shaped hollow bodies 94 without any modifications being necessary.

[0085] Reference symbol list

[0086] 10 State-of-the-art device

[0087] 12 hollow bodies

[0088] 14 housings

[0089] 16 Housing opening

[0090] 18 Cover

[0091] 20 support wall

[0092] 22 Process room

[0093] 24 passage opening

[0094] 26 Locking device

[0095] 28 through hole

[0096] 30 transport containers

[0097] 32 floor wall

[0098] 33 Hollow body inner surface

[0099] 34 side wall

[0100] 35 Hollow body outer surface

[0101] 36 Opening

[0102] 37 Support wall section

[0103] 38 edge area

[0104] 39 contact area

[0105] 40 Cleaning device

[0106] 41 first channel

[0107] 42 first cleaning head

[0108] 44 wall section

[0109] 46 Cleaning opening

[0110] 48 locking bodies

[0111] 50 recording unit

[0112] 52 Lid De eke inner surface

[0113] De eke lauf en fläche further first cleaning head second cleaning head

[0114] Fluid guide unit first supply channel first discharge channel first end second discharge channel first cleaning nozzles further first cleaning nozzles second cleaning nozzles

[0115] Pipe body

[0116] Secondary channel first drying nozzles further first drying nozzles second drying nozzles proposed device

[0117] 922 proposed device

[0118] hollow body

[0119] The disgust on the surface

[0120] cleaning head

[0121] Cleaning nozzles

[0122] Drying nozzles

[0123] Adjustment device

[0124] Coupling unit additional cleaning nozzles additional drying nozzles 112 infrared diodes

[0125] 114 Particle measuring device

[0126] 116 flexible cover a spray angle

[0127] A distance

[0128] Dl first axis of rotation

[0129] D2 second axis of rotation D3 third axis of rotation

[0130] D4 fourth axis of rotation

Claims

Device (92) for cleaning pot-shaped hollow bodies (94), in particular transport containers (30) for semiconductor wafers or for EUV lithography masks, wherein the hollow body (94) - a bottom wall (32) and one or more side walls (34) forming a hollow body inner surface (33), - an opening (36) opposite the bottom wall (32) which is enclosed by the side wall (34), and - and a lid support surface (96) formed by the side wall (34), onto which a lid (52) can be placed to close the hollow body (94), wherein the device (92) - a support wall (20) on which the hollow body (94) can be placed, - at least one through opening (24) formed by the support wall (20), - a cleaning device (40) with which a cleaning fluid can be dispensed for cleaning the lid support surface (96) when the hollow body (94) is placed on the support wall (20), wherein - the cleaning device (40) has a cleaning head (98) which o protrudes beyond the through-opening (24) and / or can be inserted into the hollow body (94) when the hollow body (94) is placed on the support wall (20), and o has a number of cleaning nozzles (100) through which the cleaning fluid can be applied to the lid support surface (96). Device (92) according to claim 1, characterized in that the cleaning head (98) has a A number of drying nozzles (102) with which a drying gas can be applied to the lid support surface (96). Device (92) according to one of claims 1 or 2, characterized in that the cleaning head (98) is rotatably and / or translatorily movable. Device (92) according to one of the preceding claims or according to one of claims 2 or 3, characterized in that the cleaning fluid and / or the drying gas can be delivered at a spray angle (α), wherein the cleaning head (98) has an adjusting device (104) which interacts with the cleaning nozzles (100) and / or with the drying nozzles (102), with which the spray angle (α) can be adjusted. Device (92) according to one of the preceding claims, characterized in that the cleaning head (98) has a number of infrared diodes (112) with which the lid support surface (96) can be heated.Device (92) according to one of the preceding claims, characterized in that the cleaning head (98) has an outer shape that at least approximately follows the course of the hollow body inner surface (33), so that the distance between the hollow body inner surface (33) and the cleaning head (98) is constant or nearly constant. Device (92) according to one of the preceding claims. characterized in that the device (92) has at least one coupling unit (106) for coupling sound waves into the cleaning fluid. Device (92) according to one of the preceding claims, characterized in that the device (92) comprises a first discharge channel (70) with a first end (72), wherein the first discharge channel (70) is in fluid communication with the first end (72) exclusively with the through-opening (24), with which the cleaning fluid discharged by the cleaning device (40) can be discharged and in which a particle measuring device (114) for determining the particles contained in the cleaning fluid is arranged. Device (92) according to one of the preceding claims, characterized in that the cleaning head (98) has a number of further cleaning nozzles (108) for cleaning the hollow body inner surface (33).Device (92) according to one of the preceding claims, characterized in that the cleaning head (98) comprises a flexible sleeve (116) which can be converted from a contracted state to an expanded state and back again with the cleaning fluid and / or the drying gas. A method for cleaning pot-shaped hollow bodies (94), in particular transport containers for semiconductor wafers or for EUV lithography masks, using a device (92) according to one of the preceding claims, comprising the following steps: - Placing the hollow body (94) on the support wall (20), - Dispensing a cleaning fluid for cleaning the lid support surface (96) by means of a number of cleaning nozzles (100) arranged on the cleaning head (98) of the cleaning device (40) such that the cleaning fluid is applied to the lid support surface (96), and - Discharging the cleaning fluid by means of the first discharge channel (70). Method according to claim 11, comprising the following steps: - Determining the particles contained in the cleaning fluid by means of the particle measuring device (114) arranged in the first discharge channel (70), and - Stopping the dispensing of the cleaning fluid when a particle-related threshold value is exceeded or fallen below. Method according to one of claims 11 or 12, comprising the following steps: - Complete flooding of the hollow body inner surface (33) limited space with the cleaning fluid, and - Coupling sound waves into the cleaning fluid by means of a coupling unit (106). Method according to one of claims 11 to 13, comprising the following steps: - Cleaning the lid support surface (96) using the cleaning nozzles (100), and time-delayed cleaning of the hollow body inner surface (33) using the further cleaning nozzles (100).

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