The invention relates to the domain of transport systems in the field of the treatment of objects, in particular in the presence of chemically aggressive media and/or under clean or ultra clean room conditions. The invention particularly relates to a treatment plant with a carrier less transport system for the handling of objects within one or between several such plants.

For reasons of exact discernability of the subsequently used terms, the same are firstly defined. Accordingly, a "treatment plant" is a plant which serves for the e.g. wet chemical treatment of "objects". These objects are e.g. substrates as they are used in the semiconductor- or solar cell production. Therein, the treatment takes place in a "process room" which is provided therefore. The process room comprises a treatment room in which the objects are contacted with a process fluid (liquid or gas) that causes the treatment. The remaining part of the process room can be partly or entirely filled with e.g. a medium that does not serve for the direct treatment, such as e.g. a protective or flushing gas. The term "treatment" comprises each manipulation of the objects within the treatment plant or between treatment plants. The handling comprises the taking up of individual or stacked objects, their transport into or out of the region of the process room, as well as the putting down of the objects at an according place. The handling takes place by use of a "transport system". Individual functional parts of the transport system that serves for the handling are at least partially arranged in a "drive room" which therefore must be differentiated from the process room, since no treatment of the objects shall take place in the drive room. In order to avoid a contact of the objects with undesired particles, the respective regions (process room, connections to up- and downstream arranged

CONFIRMATIONC ^ further plants) are often designed as "clean room" which is characterized by an exceptionally low particle concentration. Often, a "grey room" with limited access that surrounds the clean room is arranged upstream to the same in order to achieve a stepwise reduction of the particle concentration.

Treatment plants are used for the treatment of objects such as e.g. substrates in the semiconductor production. These can be arranged stand-alone or also sequentially one after another, so that a sequence of process steps can be carried out which is necessary for the production of the product.

In order to avoid a contamination of the objects with particles from the air, the objects are usually transported to the treatment plant in according containers such as e.g. FOUP

(Front Opening Unified Pod), SMIF (Standard Mechanical Interface), or FOSB (Front Opening Shipping Box). Preferably, the containers are hermetically sealed and opened only within the treatment system and made available to the treatment medium. Where appropriate, the objects are transported in receptacles ("carriers") by use of a transport system into the process room and, after the treatment, out of the same again.

A disadvantage of the use of carriers is the fact that, depending on the configuration, they cover certain areas of the objects to be treated, which therefore may not be completely exposed to the treatment medium. In the case that the treatment fluid hits the objects predominantly from one direction (for example, using gas nozzles), the carrier or its components can also have a shading effect. The same is true for example for the treatment of objects with ultrasound or megasound. In addition, the areas of the objects which have a direct physical contact with the carrier are covered, so that no treatment can take place there. Also often, a drag-over of media by the carrier is observed. Finally, initially undetected damages of carriers that barely can not be avoided during their handling can lead to a contamination of the media and/or the objects to be treated because of the associated particle detachment. For this reason, there are also solutions that provide a direct handling of the objects without any carriers. In the context of the transport system, an according gripper mechanism must be provided so that the object (s) can be removed safely from a container, moved in and out of the process room, and then stored at a suitable locality again.

At least parts of the transport system are naturally connected with the process room. A contamination of the mostly high- purity process room can take place during operation of the transport system, since each transport system comprises moving parts such as bearings or one or more drives. These moving parts create a certain abrasion, which, in contact with the objects to be treated, can result in contamination up to destruction of the sensitive functional surfaces.

Another contamination problem occurs in case of maintenance of the transport system, such as e.g. by repairing or replacing parts. On one hand, an increased danger of the escape of particles results from the maintenance itself at the according, particularly at the moving parts, for example, from dismantled bearings or drives. On the other and, plants according to the state of the art usually have one or more maintenance positions for the transport system which are arranged for reasons of accessibility in the area of the product entries and/or exits of the plants. In the case of maintenance, therefore also the mechanic who must enter the region of the transport mechanism for the maintenance and thus, of the process room, drag in particles. However, particularly problematic is the case of a defect of the drives which are responsible for the positioning of the transport system, as this may no longer be brought into the maintenance position. For maintenance and repair, parts of the plant cover must be removed or an access via the process room must be created, so that particles can contaminate virtually unhindered all regions of the plant, in particular also the process room, and need to be removed usually at great expense following the work. It is also known that chemically aggressive treatment media, as they are particularly used in semiconductor manufacturing, may affect parts of the transportation system coming in contact with these media due to corrosion. This is particularly true for the moving parts of it. Also well known is that the condensation of chemical vapours leads to the crystallization and deposition of salts in the interior space of the process room. These salt crystals can then detach during the transport of the objects, in particular, from the components of the moving parts located in the process room, which subsequently leads to a contamination or damage of the surfaces of the objects.

For this reason, measures must be taken to avoid a contamination of the process room with particles. Further, a contact of the moving parts of the transport system with the treatment medium and its gases is to be avoided as well.

Object of the invention is therefore the provision of a treatment plant for the treatment of objects while avoiding the disadvantages of the prior art, s well as a method using the same. Therein, the treatment plant shall allow a handling of the objects to be treated without additional carriers, as well as prevent a contamination of the process room by particles originating from the moving parts of the transport system. A particle entry shall largely be avoided even during maintenance of the transport system. Finally, the vulnerabil- ity of the transport system by chemically aggressive media shall be reduced far as possible. The object of the invention is achieved by independent claims 1, 9 and 12. Advantageous embodiments can be taken from the subclaims, the figures, as well as the following description.

The presently described treatment plant serves for the carrierless handling of objects while largely avoiding the drag-in of particles into the region in which the actual treatment takes place. The product entries and exits of the below-described exemplary embodiment of a treatment plant according to the invention are respectively arranged at the "sides" of the plant, wherein its "front side" is preferably facing a clean room. The "back side" is accordingly facing away the front side and thus the clean room. The distance between entry and exit runs in transport- or X-direction. In contrast, the vertical is marked with Z-direction. Naturally, a plant according to the invention can comprise several loading stations. Furthermore, embodiments are included in which the product entries and exits are on the same side of the plant .

The treatment plant according to the invention is divided into several rooms which are partially arranged separated from each other. The actual treatment of the objects takes place in a process room. The process room comprises at least one treatment room for reception of a treatment medium. Suitable treatment media are both liquids and gases. Furthermore, the treatment plant comprises a transport system for the handling of the objects. The term handling comprises any manipulation of the objects, i.e. the taking, moving and putting down of the objects within a treatment plant, and possibly also the transport of the objects from one treatment plant into another. It is preferably provided that the handling takes place carrierless. This means that the objects to be treated are not arranged during the treatment in any container such as e.g. a carrier, but that they are taken up loosely, either individually or grouped, and that in particular they undergo the treatment in this formation. Accordingly, the transport system contacts the objects to be treated directly, i.e. without a further intermediary component.

For this, the transport system according to the invention comprises at least one gripper mechanism for gripping the objects. It is provided that at least those parts of the gripper mechanism which are located in the process room or protrude into the same are designed with no moving parts and/or bearings. Further, the transport system comprises at least one drive with moving parts and/or bearings for moving and actuating the gripper mechanism. This drive can be selected from all drives known from the art, and can be for example a hydraulic, pneumatic, or electric drive. Particularly suitable, however, are those drives which are characterized by a low particle generation during operation, or which are equipped with appropriate retention systems for particles. For generation of the Z-travel, the scissors lift described in more detail later on particularly comes in question, in which the friction surfaces are arranged beyond the critical area which must be considered for a possible contamination. Moreover, a scissors lift has swivel bearings, significantly reducing the formation of particles. Further, according to the invention, guides, drives, and bearings, which are connected to a suction device, are particularly suitable.

Since by definition, the transport system also serves for a movement of the gripper system in X-direction that extends between product entry and exit of the plant as mentioned above, preferably also here, accordingly suitable drives and bearings are being used.

For the avoidance of a contamination, as provided by the invention, of the process room with particles, it is now provided that at least all the moving parts and bearings of the transport system are exclusively located in a drive room which is separate from the process room. Through this physical separation between the process room and the drive room in which the particle generating moving parts are located, it is achieved that the impurities that accumulate during operation of the transport system do not enter the process room. Since this separation is purely structural, one can speak in this context also of a "passive" separation of the two rooms.

In addition, it can be provided that the region of the drive room is continuously or intermittently freed of any accumulated particles. This can e.g. be done by flushing using a flushing gas which is drawn off through appropriate exhaust ducts and, optionally, filters.

Another source of unwanted particles represents the access to such a treatment plant in the event of maintenance, for example due to functional testing, cleaning, or defect repair. Therefore, it is further also provided according to the invention that, for the avoidance of a contamination of the process room, the drive room comprises a separate maintenance access for the maintenance of the transport system' s components being located in the drive room, wherein it is provided according to the invention that maintenance is possible independent of the positioning of the transport system's components being located in the drive room. This means that in case of maintenance no access through the process room is necessary, which would result in an according contamination. This is especially also the case if the moving parts of the transport system are e.g. not just located on the

(easily accessible) beginning or end (maintenance access) of the plant. Accordingly, the particles which are dragged in during the actual maintenance, and the particles which are dragged in by the maintenance staff, are both kept away from the process room. Particularly preferred, it is provided that the maintenance access is arranged at a side which faces away from a clean room, and therefore, from the process room. Accordingly, entering the clean room for maintenance is omitted, so that the drag-in of particles associated with this maintenance into the clean room is omitted, from where the maintenance otherwise would have to take place.

It is therefore preferred that the maintenance access to the drive room takes place from a grey room. This means that the treatment plant is arranged such that their back side and in particular the maintenance access is located adjacent to a grey room. This grey room has usually a higher particle concentration as compared to the process room which preferably is designed as a clean room. However, the same is lower than the particle concentration in normal ambient air. It is clear that the grey room can be provided not necessarily as a closed room, but also as a semi-open region.

According to a preferred embodiment of the invention, an air curtain with a targeted air flow is provided between drive room and process room for the avoidance of a contamination of the process room with particles or for the avoidance of a contamination of the drive room with process fluid such as in particular chemical vapours. Through this additional "active" measure, particles that take their way towards the process room notwithstanding the above measures will be intercepted at the border between drive room and process room and taken away. At the same time e.g. chemical vapours from the process room are avoided from entering into the drive room, where they could develop for example corrosive effects. The task of the at least one drive is a provision of the kinetic energy in X- as well as in Z-direction which must be transferred to the gripper system. According to the invention, it is provided that the gripper mechanism comprises at least in the region of the process room no moving parts or bearings in order to avoid a particle contamination by abrasion of moving parts or bearings. Particularly preferred, it is therefore provided that at least one scissors lift is provided for the vertical positioning of the at least one gripper mechanism and thus for lifting and lowering of the objects. Particularly preferred, it is further provided that this scissors lift is mounted on or to one crossbeam running in X- direction on which it may slide, for example by means of according rails. All moving parts (bearings, drives) of the scissors lift and of the crossbeam are accommodated in the drive room according to the invention.

According to a particularly preferred embodiment, a labyrinth arm can be used in conjunction with the scissors lift, wherein this is a special embodiment of the arm protruding from the drive room into the process room, at whose end which faces away from the drive the actual gripper mechanism is arranged. Such an arm is characterized by its multiply bent or angled, non-linear design, so that it can bridge in an appropriate manner and without moving joints several bends of a labyrinth like wound connecting path between drive and process room. With regard to particles, the structural design of the path causes a separation of drive room and process room. Particles coming from the drive room are caught in such a "labyrinth" at least to a large extent and do not enter the process room, while kinetic energy which is necessary for a gripping motion can be freely transferred from the drive room to the portion of the gripper mechanism which is present the process room.

Preferably, the drive comprises three linear and two rotation axes. The first linear axis relates to the motion in the X- direction, i.e. it serves for the transport of the objects between the individual treatment and storage stations of the treatment plant. The second linear axis relates to the Z- travel which, as mentioned above, is preferably designed as a scissors lift. The third linear axis relates to the motion in Y-direction and serves for the precise positioning of the objects inside the media room. The two rotation axes serve for the actuation of a preferred embodiment of the gripper mechanism as described in the figures 1 and 2. As required, however, one or more axes can be replaced or supplemented by further linear or rotation axes.

In order to minimize the particle formation which starts from the moving parts of the transport system from the very beginning, it is preferably provided that, for minimizing the particle formation in the drive room, swivel bearings and/or drives that can be sucked off are provided. Swivel bearings are characterized by a particularly low particle formation during operation. A suction in particular of the drives which naturally tend to a significant particle production can help to get particles which are accumulated during the operation immediately removed from the drive room of the treatment plant, and not firstly enter the interior of the process room from where they are harder to remove. The described treatment plant is intended in particular for a treatment of objects that are present as flat substrates, e.g. for the treatment of semiconductor wafers. The gripper mechanism is preferably designed so that it can grip single objects or even groups of them to a stack size of e.g. 30-100 individual parts. It is intended that the original orientation of the individual objects is maintained even during treatment. In particular, the mostly flat objects are present in a stack of parts that are spaced to each other. Particularly preferred, the semiconductor wafers can have a diameter of 200 mm, 300 mm or more.

According to the invention it is provided that the objects to be treated are transported individually or also in groups to the treatment plant. Particularly preferred, the delivery can take place by means of corresponding cartridges such as FOUP, SMIF, FOSB etc. (see above), or by carriers in which the objects to be treated are placed at a distance from each other. The treatment system described is therefore particularly suitable for the wet-chemical treatment of semiconductor substrates in the context of a continuous or batchwise process line such as particularly a batch plant.

Particularly advantageous proves the spatial separation of drive and process room and the resulting avoidance of contact of moving parts of the transport mechanism with chemically aggressive media. In particular, a corrosion of bearings and actuators which are particularly susceptible to corrosion, and whose exchange is also possible only with increased effort, is avoided to a large extent. Furthermore, in addition to the "passive" spatial separation of the two rooms, in particular the above described "active" separation ensures as well that aggressive vapours can not get out of the process room into the drive room. The invention also discloses a process for the carrierless handling of objects within one or between several treatment plants. For this, the method according to the invention provides that a treatment plant as described above is used.

According to the invention, it is provided that the method comprises at least one of the following steps:

- positioning of the gripper mechanism at the objects which are available outside the process room;

- gripping of one or several objects with the gripper mechanism; - moving of the gripper mechanism into the at least one treatment room of the process room by means of the transport system;

- positioning and, optionally, putting down of the objects in the treatment room;

- optionally resting inside the treatment room during a treatment time;

- optionally taking up the objects again;

- moving of the gripper mechanism out of the process room' s at least one treatment room by means of the transport system;

- putting down of the object (s) outside of the process room.

During the execution of all the above steps, the moving parts of the drive of the transport system are always arranged in the separate drive room in order to ensure the avoidance of a contamination of the process room with particles as desired according to the invention. In this way, at no moment the danger exists that particles can reach from the region of the drive into the process room due to operation of the transport system.

Furthermore, it is provided according to the invention that the air curtain between the drive and process room can be, but not necessarily is, activated at any time, but especially during treatment and transport of the objects, so that a crossing of particles accumulating in the drive room into the process room and thus, a contamination of the same and of the surfaces of the objects, is avoided. At the same time, e.g. chemical vapours from the process room are avoided from penetrating into the drive room. It is clear that for the case of several media rooms within a treatment plant initially an incremental transport into the next treatment room can take place before the treatment plant's process room which comprises all the media rooms is ultimately left. However, the transport always takes place by means of the transport system according to the invention.

The method according to the invention further comprises steps for the maintenance of the transport system while avoiding a contamination of the process room with particles. Regarding the details of corresponding device's components reference is made to the above descriptions regarding the plant. Accordingly, for maintenance of the transport system the following steps are to be performed:

- opening the maintenance access which is facing away from the process room;

- optionally positioning of the gripper mechanism of the transport system in a position in the region of the maintenance access (maintenance position) ;

- carrying out the maintenance works on the transport system;

- closing the maintenance access.

As a result according to the invention, all maintenance work on the transport system is carried out without entering the process room. In this way it is ensured that unwanted particles are dragged into the process space neither by the maintenance itself nor by the maintenance personnel performing the maintenance.

The positioning of the gripper mechanism is omitted if the same is completely accessible via the maintenance access, or if other parts of the transport system should be serviced that are accessible without a ( re ) positioning of the gripper mechanism. The invention discloses a method for maintenance of the transport system (6) comprised by a treatment plant together with a process room with at least one treatment room, a drive room which is separated from the process room and which comprises a maintenance access which is facing away from the process room, while avoiding a contamination of the process room with particles and/or a contamination of the drive room with vapours, the method comprising the steps of providing such treatment plant, entering the drive room via the maintenance access, and carrying out the maintenance work on the transport system' s moveable and immobile parts that are accessible from said drive room.

In case that the maintenance access is initially closed, optional steps relate to the opening of this access prior to performing the maintenance work, and/or subsequently closing the access again.

According to a particularly preferred embodiment it is provided that during performing the steps according to the invention, for active separation of the process room and the drive room, an air curtain with a targeted air flow between drive room and process room is switched on, preferably at all times, for the avoidance of a contamination of the process room with particles or for the avoidance of a contamination of the drive room with process fluid. In this way, a further reduction of the probability of a crossing of particles from the drive- into the process room takes place, what is true also for the possible crossing of process fluid, such as in particular of chemical vapours, from the process- into the drive room. However, it is also possible that the air curtain is only temporarily present, e.g. only in the case of processing or maintenance, and/or that it is not switched on at all times, but e.g. only when objects are present in the treatment room. The invention advantageously avoids a contamination of the process room with particles which can occur during operation of a transport system, or also during maintenance of the plant interior, in particular of its moving parts. At the same time the design according to the invention protects sensitive components such as bearings and the like from aggressive media and related corrosion.

Description of figures

Figure 1 shows the treatment plant 1 according to the invention in a perspective view.

Figure 2 shows an exemplary and schematic representation of the treatment plant according to the invention in a side view.

Figure 3 shows a preferred embodiment of the transport system

6 of the treatment plant according to the invention.

In figure 1, the treatment plant 1 according to the invention is shown in a perspective view with its components, but without a housing which separates the interior of the plant according to the invention from the surrounding. In the foreground, the process room 2 is shown in which two containers 3 are arranged, of which the one that is represented in the left of the picture contains an object to be treated 4. In this case, the object to be treated 4 is a flat, round substrate. The two containers 3 are each arranged in a treatment room 5A, 5B which is formed as a basin, which each respectively receives a treatment medium. Accordingly, in this case the process room comprises two media rooms 5A, 5B, which preferably may contain different media such as e.g. a treatment and a cleaning liquid. The treatment plant 1 according to the invention comprises a transport system 6, for example for the transport of the substrates 4 which optionally can be present in a multitude from a treatment room 5A into the subsequent treatment room 5B. Only a gripper mechanism of this transport system 6 protrudes into the process room 7. In the illustrated figure, the gripper mechanism 7 is designed in two parts. The components of the gripper mechanism 7 projecting into the process room 2 have no moving parts but are composed solely of rigid elements.

At the end of the gripper mechanism 7 which faces away from the treated objects 4, its two parts are each mounted to a respective swivel kinematics 8 which allows an opening and closing of the gripper mechanism 7. These in turn are arranged on the upper platform of a scissors lift 9, which allows a movement of the gripper mechanism 7 in the Z-direction (vertical direction) , and which is presently shown in an almost extended position. The scissors lift 9 forms together with further moving parts the drive 10 of the transport system 6. All moving parts of the transport system 6 are accommodated in a drive room 11 which is separated from the process room 2. For an axial motion of the transport system 6 in the transport direction, indicated by the arrow 12, the same is arranged movable on according rails 13. The maintenance of the transport system 6 can be carried out from the back side of the treatment plant, which is indicated in the figure shown by the arrow 14. In this way, maintenance of moving parts is possible without having to enter the process room 2 and thus possibly contaminate the same with particles. The figure 2 shows an exemplary and schematic representation of the treatment plant 1 according to the invention in a side view. The treatment plant 1 is dimensioned and arranged to separate a grey room 17 from a clean room 18. The latter may optionally have a filter ceiling. On the (clean room facing) front side, the treatment plant 1 has a window 20 from which the objects to be treated 4 which are located in the process room 2 can be observed for example for inspection reasons. The lower region of the process room 2 is provided as a treatment room 5, since here the direct contact of the objects 4 with the process fluid takes place. A media supply 5 ' (dotted line) which supplies the treatment room 5 with treatment fluid is arranged below the treatment room 5. Optionally, a flow box 21 with a downward directed gas flow is arranged above the process room 2.

Furthermore, an air curtain 16 (indicated by arrow 16) with an horizontally aligned air flow is located in the region between the process room 2 and the drive room 11, which ensures that both a crossing of particles from the drive room 11 into the process room 2, as well as a crossing of process fluid into the opposite direction is avoided.

The objects 4 are held according to the representation by means of a gripper mechanism 7. The latter extends upward into the drive space 11, which is arranged the back region of the treatment plant 1, and in which also the scissors lift 9 that is responsible for the Z-stroke, as well as other moving parts of the transport system are arranged (not shown) .

In the back (grey room facing) region of the treatment plant 1, a chemistry dosing unit 22 as well as an electric room 23 are further arranged. All of these components 11, 22, 23, 5 ¹ are accessible from the region of the grey room 17, so that a drag-in of particles into the process room 2 due to maintenance is omitted, wherein it is irrelevant according to the invention in which position the transport system 6 is located, which is moveable on a corresponding crossbeam with rails 13 perpendicular to the drawing plane. Figure 3 shows a preferred embodiment of the transport system 6 of the treatment plant according to the invention as a perspective view.

In the foreground, the gripper mechanism 7 can be seen. The position of an object to be treated 4 formed as a flat substrate being clamped between the pincers of the two-part designed gripper mechanism 7 is shown (dashed) . At the upper end of the gripper mechanism 7, the swivel kinematics 8 is shown which is necessary for the operation of the gripper mechanism 7. The swivel kinematics itself is arranged on the top platform of a scissors lift 9, which presently is shown in an almost extended position. The latter in turn is attached to a drive 10 (not shown) which is axially movable in the direction of the arrow 12. The drive is arranged in a separate drive room (not shown) , which is separated from the process room 2 (not shown) by an air curtain 16 indicated by the arrows 16. Because of the air curtain 16, particles that could possibly get from the moving parts of the drive 10 from the drive room 11 into the process room 2 are being transported away in a catchment device (not shown) in time prior to reaching the process room. Similarly, e.g. chemical vapours are avoided from crossing into the opposite direction.

List of references

1 treatment plant

2 process room

3 container

4 objects to be treated

5 treatment room

5A first treatment room

5B second treatment room

5' media supply

6 transport system

7 gripper mechanism

8 swivel kinematics

9 scissors lift

10 drive

11 drive room

12 arrow, transport direction

13 rails

14 arrow

15

16 air curtain

17 grey room

18 clean room

19

20 window

21 flowbox

22 chemistry dosing unit

23 electric room