Abstract:
An apparatus for recovery in the system for processing disc-shaped objects is disclosed. The system is provided with an OHT that places and/or removes at least one FOUP containing disc-shaped objects onto and/or off of a loadport. A light barrier arrangement is attached in front of a region of the loadport, which is designed for placing and/or removing a FOUP by means of the OHT. An input device is provided through which the OHT resumes the process of placing and/or removing the FOUP when this is stopped by an interruption of the light barrier arrangement.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority to German patent application number DE 10 2004 062 594.8, filed Dec. 24, 2004, which is incorporated herein by reference in its entirety.  
       FIELD OF INVENTION  
       [0002]     The invention relates to an apparatus for recovery in a system for processing disc-shaped objects. In particular, the invention relates to an apparatus for recovery in a system for processing disc-shaped objects with an OHT provided to the system that places and/or removes at least one FOUP with disc-shaped objects on and/or from a loadport.  
         [0003]     Furthermore, the invention relates to a method for recovery in a system for processing disc-shaped objects.  
       BACKGROUND OF THE INVENTION  
       [0004]     In semiconductor manufacturing, wafers or disc-shaped substrates, respectively, are sequentially processed in a multiplicity of processing steps during the production process. The disc-shaped substrates are transported to the systems in containers, the FOUPs. The various processing steps are then carried out in the systems. The FOUPs are delivered or transported by an OHT to the system&#39;s loadport.  
         [0005]     US patent application 2003/0053892 A1 discloses how the individual FOUPs are transported to a loadport by means of an OHT. However, this patent application does not disclose a device that monitors whether objects or the like are present in the transport path of the FOUP from the OHT to the base plate of the loadport.  
         [0006]     US patent application 2002/0155641 A1 discloses an apparatus for positioning a loadport in a processing machine. The apparatus has a base plate in which at least two vertical bore holes are implemented that interact with the corresponding pins in the processing machine. A positioning block is provided for positioning in which at least one horizontal borehole is provided. The position of the loadport is determined via the borehole by means of a light source and a detector.  
       SUMMARY OF THE INVENTION  
       [0007]     The object underlying the invention is to create an apparatus that enables quick and inexpensive continuation of operation in case of a malfunction in placing and/or removing a FOUP on and/or from a loadport.  
         [0008]     This object is solved by an apparatus for recovery in a system for processing disc-shaped objects, whereby an OHT that places and/or removes at least one FOUP containing disc-shaped objects on and/or off from a loadport is provided to the system; in that a light barrier arrangement is attached in front of an area of the loadport, which is implemented for placing and/or removing a FOUP by means of the OHT, and in that an input device is provided by which the OHT can be reset when the placing and/or removing has been stopped by an interruption of the light barrier arrangement.  
         [0009]     A further object of the invention is to make available a method by which quick and inexpensive continuation of operation with the apparatus is possible when a malfunction in placing and/or removing a FOUP on and/or from a loadport occurs.  
         [0010]     This object is solved by a method with the following characteristics:  
         [0011]     interruption of the light barrier arrangement during placing or removing a FOUP on and/or from a loadport;  
         [0012]     monitoring whether interruption of the light barrier arrangement is ongoing; and  
         [0013]     recovery and continuation of placing of the FOUP or removing of the FOUP on and/or from the loadport.  
         [0014]     It is particularly advantageous when an OHT is provided with which at least one FOUP with disc-shaped objects may be placed and/or removed on and/or from a loadport, for recovery in the system for processing disc-shaped objects. The system is provided with a light barrier arrangement, whereby an input device is provided by means of which the interruption of the process of placing and/or removing a FOUP by the OHT can be reset when the interruption in placing and/or removing is caused by an interruption in the light barrier arrangement.  
         [0015]     The light barrier arrangement comprises a linear arrangement of several individual light barriers, whereby each is comprised of a light source and a receiver. A first and a second side wall are attached above the loadport. The input opening for the system is implemented between the first and the second side wall. The light barrier arrangement is attached to an end of the first and the second wall that is facing away from the system.  
         [0016]     The input device is a visual display screen that is connected to a control unit for the system and the OHT. The visual display screen can be implemented as a touchscreen. The system is connected to a signal tower that comprises several signal lights.  
         [0017]     The method for recovery in the system for processing disc-shaped objects is equally advantageous. Here, the interruption in the light barrier arrangement during placing or removing a FOUP on and/or from a load transport is first registered, and the loading/unloading process immediately interrupted. Then monitoring begins to determine whether the interruption of the light barrier arrangement is ongoing. Finally, recovery is undertaken and placing the FOUP or removing the FOUP on and/or from the loadport is resumed.  
         [0018]     Further advantageous developments of the invention may be inferred from the subclaims.  
         [0019]     The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:  
         [0021]     The subject of the invention is schematically represented in the diagram, and is described below based on the figures. They show:  
         [0022]      FIG. 1 a  schematic view of a system that processes disc-shaped semiconductor substrates, whereby the disc-shaped semiconductor substrates are delivered in a FOUP via an OHT (overhead hoist transportation) to a loadport of the system;  
         [0023]      FIG. 2 a  perspective view of a loadport connected to a system for processing disc-shaped substrates;  
         [0024]      FIG. 3 a  perspective view of a loadport connected with the light barrier arrangement according to the invention;  
         [0025]      FIG. 4 a  schematic representation of a block diagram of the method according to the invention for placing a FOUP; and  
         [0026]      FIG. 5 a  schematic representation of a block diagram of the method according to the invention for removing a FOUP. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0027]      FIG. 1  is a schematic view of a system  100  that processes disc-shaped semiconductor substrates. The disc-shaped semiconductor substrates are delivered to a loadport  20  of the system  100  in a FOUP  101  via an OHT  102  (overhead hoists transportation). The loadport  20  comprises a base plate  21  onto which the FOUP  101  may be placed so that the disc-shaped substrates may be processed by the system  100 . The system  100  is further provided with a signal tower  105  that may comprise several light sources  104  of varying color. The lights  104  give the operator an indication of potential errors. Furthermore, the system  100  is provided with a visual display screen by means of which the operator may make inputs. The visual display screen makes available to the operator several input fields  107  for the purpose. Thus, for example, the operator may initiate automatic recovery via at least one of the input fields  107 . Similarly, the operator may confirm a manual reset of the system  100  via the visual display screen.  
         [0028]      FIG. 2  is a perspective view of a loadport  20  that is connected to a system  100  for processing disc-shaped substrates. The loadport  20  is connected with the system  100  and forms an interface between the system  100  for processing the disc-shaped substrates and that for inputting disc-shaped substrates in the system  100 . The loadport  20  has a base plate  21  onto which a FOUP  101  can be placed. The base plate  21  itself bears a connection plate  22  that is implemented in accordance with the SEMI E15 standard and interlocks with a bottom side (not represented) of the FOUP  101 . By interlocking, the FOUP  101  is securely seated on the loadport  20 . In addition to the aforedescribed interlocking, coupling elements (not represented) between the FOUP  101  and a loadport  20  grip each other to achieve a secure seat. A FOUP  101  filled with disc-shaped objects can therefore not be accidentally knocked off of the loadport  20 , so that an additional level of security to protect the disc-shaped objects is built in. In addition, several lights  23  are provided at the loadport  20 , which indicate the correct positioning of the FOUP  101  on the loadport  20 . Similarly, the lights  23  indicate whether the FOUP  101  has been placed on the loadport or whether the present FOUP may be removed.  
         [0029]      FIG. 3  is a perspective view of a loadport  20  with the operating element  30  according to the invention. The operating element  30  makes it possible for a FOUP  101  to be placed onto the loadport without initializing the lock device, by means of which the FOUP  101  is prevented from being removed before the disc-shaped objects contained in the FOUP  101  have been processed by the system  100 . Once the operator has placed a FOUP  101  on the loadport and presses or activates the operating element  30 , the disc-shaped objects contained in the FOUP  101  are processed. If the operator parks a FOUP  101  on the loadport  20  without activating the operating element  30 , the FOUP  101  is secured and fixed on the loadport  20  and can be removed and placed again as desired. A light barrier arrangement  24  is provided in a suitable manner at the loadport  20 , with which events or objects that should not be present in the load path of the FOUP  101  by means of the OHT  102  may be detected or registered. An event may, for example, include the operator&#39;s interrupting the light barrier arrangement  24  with his elbow. The light barrier arrangement  24  is a linear arrangement of several individual light barriers, whereby each comprises a light source and a receiver. For the spatial arrangement of the light barrier arrangement  24  a first and a second wall  26  and  27  are attached above the loadport  20 , and between which an input opening  28  for the system is provided. The light barrier or the light barrier arrangement  24  are each provided as a linear arrangement at the end of the first and the second wall  26  and  27  that faces away from the system.  
         [0030]      FIG. 4  is a schematic representation of a block diagram of the method according to the invention for placing a FOUP  20 . The E84 load sequence  40  between the OHT  102  and the loadport  20  has begun. During the process of placing the FOUP  101  via the OHT  102  there is an interruption  41  of the light barrier, which interrupts the process of placing the FOUP  101 . An alarm is given  43  on the visual display screen and/or signal tower. The interruption of the light barrier is eliminated  44  by the operator, if it is still ongoing. The system conducts a status inquiry  45  to determine whether the interruption has been eliminated or not. If the result of the status inquiry  45  is that the interruption has not been eliminated, a service technician will have to be brought in. If the result of the status inquiry  45  is that the interruption was eliminated, a further status inquiry  46  is made to determine whether the system should undertake an automatic recovery. If the result of the status inquiry  46  is that no automatic recovery should be undertaken, there then follows an action  471 , by which the OHT is manually reset. A confirmation  472  that a manual reset has taken place appears on the visual display screen. The alarm  473  of the light barrier is reset, and the E84 load sequence is resumed  474 .  
         [0031]     If the result of the status inquiry  46  is that an automatic recovery should be undertaken, this is then done by the operator&#39;s selection  481  of automatic recovery. After the selection  481 , the light barrier is reset  482 . Subsequently, an ES signal is given that permits resumption  483  of the E84 load sequence. Finally, the E84 load sequence is concluded  484 . This means that placing of the FOUP  101  on the loadport has been concluded.  
         [0032]      FIG. 5  is a schematic representation of a block diagram of the method according to the invention for removing a FOUP  101 . The E84 on load sequence  50  between the OHT  102  and the loadport  20  has begun. During the process of removing of the FOUP  101  via the OHT  102  there is an interruption  51  of the light barrier, and the process of removing the FOUP  101  is therefore interrupted. An ES signal is then given  52  so that the loadport  20  stops the OHT  102 . An alarm is then registered  53  on the visual display screen and/or a signal tower. The interruption of the light barrier is eliminated  54  by the operator, if it still exists. The system conducts a status inquiry  55  to determine whether the interruption has been eliminated or not. If the result of the status inquiry  45  is that the interruption has not been eliminated, a service technician will have to be brought in. If the result of the status inquiry  55  is that the interruption was eliminated, a further status inquiry  56  is initiated to determine whether the system should undertake an automatic recovery. If the result of the status inquiry  56  is that no automatic recovery should be undertaken, there then follows an action  571 , by which the OHT is manually reset. A confirmation  572  that a manual reset has taken place appears on the visual display screen. The alarm  573  of the light barrier is reset, and the E84 unload sequence is resumed  574 .  
         [0033]     If the result of the status inquiry  56  is that an automatic recovery should be undertaken, this is then done by the operator&#39;s selecting  581  automatic recovery. After the selection  581 , the light barrier is reset  582 . Subsequently, an ES signal is given that permits resumption  583  of the E84 unload sequence. Finally, the E84 unload sequence is concluded  584 . This means that removing the FOUP  101  from the loadport has been completed.  
         [0034]     While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.