Abstract:
A multi-chamber system includes an index station at which one or more substrate cassettes are placed, a transfer passageway having one end adjacent the index station, at least one process chamber disposed alongside the transfer passageway, and at least one substrate transfer robot disposed in the transfer passageway for receiving a substrate from the index station and by which the substrate is transferred to each process chamber. The multi-chamber system has a minimal footprint. Furthermore, the system can be easily expanded. In addition, the substrate transfer robot(s) may have a blade including two substrate supports so that the time required for moving a substrate through the system is minimized.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention is directed to a multi-chamber system for manufacturing semiconductor devices.  
         [0003]     2. Description of the Related Art  
         [0004]     In general, a cluster system is a multi-chamber type of apparatus that includes a transfer robot (or handler) and a plurality of processing modules disposed around the transfer robot. Today, there is an increasing demand for cluster systems that can execute a plurality of processes in the manufacturing of semiconductor devices and the like.  
         [0005]     For instance, a cluster system is used to dry etch semiconductor wafers with plasma. This cluster system comprises a plurality of process chambers in which a high vacuum environment, necessary for creating the plasma, is maintained. The cluster system also includes a centralized transfer chamber in which a transfer apparatus is disposed. The transfer apparatus is operative to load/unload wafers to/from the process chambers.  
         [0006]     A conventional multi-chamber system  10  of an etch facility is illustrated in  FIG. 23 . The multi-chamber system  10  has a six-sided (hexagonal) central chamber  16  and four process chambers  15  connected to respective sides of the central chamber  16 . A process is carried out on a wafer in each of the respective process chambers  15 . Two loadlock chambers  13  are connected to the remaining two sides of the central chamber  16 , respectively.  
         [0007]     The central chamber  16  of the multi-chamber system  10  occupies a large area as it accommodate six modules (the four process chambers and the two loadlock chambers) on respective sides thereof. Accordingly, the entire area of the facility is rather large and, in particular, the vacuum facility for maintaining a vacuum in the chambers must be correspondingly large and complex. Of course, the large scale of the facility is responsible for high equipment and installation costs.  
         [0008]     As the number of process chambers  15  increases, the area of the central chamber  16  must also increase. For example, if the multi-chamber system is to employ six process chambers, the central chamber must be octagonal. In this case, the central chamber would have a much larger area than if only four process chambers were employed. Therefore, if the facility requires an increase in the number of process chambers  15 , an additional centralized multi-chamber system is installed in the facility.  
         [0009]     However, multi-chamber systems have very high purchase prices and installation costs. Also, an additional multi-chamber system would occupy a rather large area. In the case in which an additional multi-chamber system is added to the facility, the footprint of the multi-chamber systems would occupy a significantly large part of the clean room of the facility. Furthermore, various components of the vacuum system and of the system for supplying gas to the process chambers and/or loadlock chambers would be duplicated.  
         [0010]     Moreover, the transfer apparatus transfers of the conventional cluster system transfers only one substrate at a time. For example, the transfer apparatus may carry a processed substrate from a process chamber to a loadlock chamber (or another process chamber) while another substrate coming from the loadlock chamber is held before it is transferred to the process chamber.  
         [0011]     These operations of the transfer apparatus, required for processing a substrate in the system, require long amounts of time. Thus, the conventional transfer apparatus impedes the production rate and, as such, contributes to the high cost of the completed products.  
       SUMMARY OF THE INVENTION  
       [0012]     An object of the present invention is to provide a multi-chamber system that occupies very little space within a manufacturing facility.  
         [0013]     Another object of the invention is to provide a multi-chamber system which minimizes the compartmental areas in which a vacuum must be maintained, thereby minimizing equipment and operating costs.  
         [0014]     Still another object of the invention is to provide a multi-chamber system that can be readily expanded.  
         [0015]     Furthermore, another object of the invention is to provide a multi-chamber system that minimizes the time required to move a substrate through the system while being processed.  
         [0016]     A multi-chamber system of the present invention comprises an index station on which one or more substrate cassettes are placed, a transfer passageway that is just wide enough to accommodate the transfer of a substrate therealong, at least one process chamber disposed alongside the transfer passageway, and substrate transfer apparatus disposed in the transfer passageway for receiving a substrate from the index station and by which the substrates are transferred to/from the process chambers.  
         [0017]     According to one aspect of the present invention, the index station may include a single substrate transfer robot having a working envelope that encompasses a substrate unloading position and is operative to remove substrates from a cassette disposed at the unloading position. In this case, the substrate transfer apparatus comprises a first transfer robot having a working envelope that encompasses the working envelope of the single substrate transfer robot and at least one of the process chambers disposed alongside the transfer passageway. Thus, the first transfer robot is operative to receive a substrate directly from the single substrate transfer robot, to load the received substrate into at least one process chamber, and to unload a substrate from at least one process chamber.  
         [0018]     The substrate transfer apparatus may also comprises a second transfer robot disposed in line with the first transfer robot. In this case, the second transfer robot has a working envelope that encompasses that of the first transfer robot and at least one process chamber disposed at the side of the transfer passageway. Thus, the second transfer robot is operative to receive a substrate directly from the first transfer robot, to load a substrate received from the first transfer robot into at least one process chamber, and to unload a substrate from at least one process chamber.  
         [0019]     On the other hand, a substrate station maybe interposed between the first and second transfer robots. The substrate station includes a substrate support configured to support a substrate. The substrate support may comprise a base, and a lifting device for lifting and lowering a substrate off of and onto the base. In this case, the working envelopes of each of the first and second transfer robots encompass the substrate station. Accordingly, substrates are transferred indirectly between the first and second transfer robots via the substrate station.  
         [0020]     Also, open spaces are left on opposite sides of the transfer passageway at the location of the substrate station. The open spaces define service areas that allow at least one said process chamber to be checked.  
         [0021]     Alternatively, and according to one aspect of the present invention, at least one loadlock chamber is connected to the transfer passageway as interposed between and directly connected to a plurality of the process chambers so as to be shared by the process chambers. In this case, the substrate transfer apparatus disposed in the transfer passageway has a working envelope encompassing the unloading position of the index station and each loadlock chamber. Thus, the substrate transfer apparatus is operative to receive a substrate from the index station, to load the received substrate into the loadlock chamber, and to unload a substrate from the loadlock chamber. A second substrate transfer robot is disposed in the loadlock chamber. The second transfer robot has a working envelope encompassing the working envelope of the substrate transfer apparatus and a plurality of process chambers. Thus, the second substrate transfer robot is operative to receive a substrate from the substrate transfer apparatus, to load the received substrate into any of a plurality of process chambers, and to unload a processed substrate from any of a plurality process chambers.  
         [0022]     According to yet another aspect of the present invention, one or more of the substrate transfer robots comprises a base, a first arm having a rear end connected to the base and supported so as to be rotatable in a horizontal plane, a second arm having a rear end connected to a front end of the first arm and supported so as to be rotatable in a horizontal plane, and a blade connected to the front end of the second arm and supported so as to be rotatable in a horizontal plane. The blade has at least two substrate supports configured to respectively support substrates in the same plane. Preferably, the substrate supports are C-shaped or are linear and elongate for supporting the bottom of a substrate.  
         [0023]     Also, one or more of the substrate transfer robots comprises an elevator for moving the blade thereof up and down. In the case in which the first and second substrate transfer robots are disposed in-line in the transfer passageway, the elevator and the different shapes of the substrate supports allow the first and second substrate transfer robots to directly transfer a substrate therebetween. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]      FIG. 1  is a plan view of a first embodiment of a multi-chamber processing system according to the present invention.  
         [0025]      FIG. 2  is a perspective view of a part of the multi-chamber processing system comprising transfer robots and some of the process chambers.  
         [0026]      FIG. 3  is a side view of a first robot of the multi-chamber processing system.  
         [0027]      FIG. 4  is a cross-sectional view of a power delivery system of the first robot.  
         [0028]      FIG. 5  through  FIG. 8  are top plan views of the multi-chamber processing system, showing the steps of loading a substrate into a process chamber.  
         [0029]      FIG. 9  through  FIG. 14  are plan views of the multi-chamber processing system, showing the steps of exchanging a substrate awaiting processing for a completely processed substrate.  
         [0030]      FIG. 15  through  FIG. 17  are plan views of the multi-chamber processing system, showing the steps of transferring a substrate from the first robot to a second robot of the system.  
         [0031]      FIG. 18  is a side view of the first and second robots, showing the steps of transferring a substrate from the first robot to the second robot.  
         [0032]      FIG. 19  is a plan view of a second embodiment of a multi-chamber system according to the present invention.  
         [0033]      FIG. 20 ( a )-( f ) are each a plan view of an embodiment of a multi-chamber system according to the present invention.  
         [0034]      FIG. 21  is a plan view of various other multi-chamber systems according to the present invention.  
         [0035]      FIG. 22  is a plan view of a third embodiment of a multi-chamber system according to the present invention.  
         [0036]      FIG. 23  is a plan view of a conventional multi-chamber system of an etch facility for manufacturing semiconductor devices. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0037]     Referring to  FIG. 1  and  FIG. 2 , a first embodiment of a multi-chamber system  100  according the present invention includes an index station  110 , a transfer passageway  120 , five process chambers  140  connected to the transfer passageway  120 , and dual substrate transfer apparatus comprising a first robot  150 A and a second robot  150 B disposed in the transfer passageway  120 .  
         [0038]     The index station  110  may comprise an equipment front end module (EFEM) having FOUP openers  112  and a single substrate transfer robot  114 . Three front opening unified pods (FOUPs)  116  are mounted on the FOUP openers  112  of the index station  110 , respectively. FOUPs are typically used as substrate carriers in mass production and can be installed at the index station  110  by means of an automatic transport system, e.g., an overhead hoist transport (OHT) vehicle, automatic guided vehicle (AGV), or rail guided vehicle (RGV). The index station  110  is connected to one end of the transfer passageway  120 .  
         [0039]     The first robot  150 A is disposed adjacent to the index station  110 , and the second robot  150 B is disposed adjacent three of the process chambers  140 . The first robot  150 A may directly transfer a substrate to either the single substrate transfer robot  114  or the second robot  150 B. To this end, the second robot  150 B has a straight blade corresponding to that of the single substrate transfer robot  114 , and the first robot  150 A has a C-shaped blade into which the straight blade of the second robot  150 B can be inserted. Furthermore, the first robot  1   50 A has an elevator for moving the C-shaped blade up and down. The second robot  150 B transfers a substrate between three of the process chambers  140 .  
         [0040]     The process chambers  140  may execute any of various substrate processing operations. For example, the process chambers may comprise a CVD apparatus for forming an insulation layer on a substrate, an etch apparatus for etching apertures or openings in a substrate that are used to form interconnect structures, or a PVD apparatus for forming a barrier layer or a metal layer on a substrate. A number of such processing apparatuses, needed to perform all of the processes for fabricating an integrated circuit or chip, may be provided. Note, however, that the multi-chamber systems of the present invention can be applied to facilities other than those for fabricating semiconductor devices, such as those for fabricating liquid crystal displays (LCD), and plasma display devices, or the like.  
         [0041]     Each of the respective process chambers  140  has a first gate  142 . The first gate  142  is selectively openable and closable for allowing a substrate to pass from the transfer passageway  120  into the process chamber  140  and vice versa. The gate  142  is a slit valve, which is well known in the art and will not be described in further detail.  
         [0042]     The first and second robots  155 A and  150 B will now be described more fully hereinafter with reference to  FIGS. 1-4 . However, the first and second robots  150 A and  150 B have the same structure except for the shape of their blades. Accordingly, the second robot  150 B will not be described in specific detail.  
         [0043]     The first robot  150 A includes a dual blade  170 A having two substrate supports  172 A and  174 A that perform a carry-in operation and a carry-out operation. The carry-in operation is an operation in which a substrate is received from the single substrate transfer apparatus  114 , and is carried into a process chamber  140 . The carry-out operation is an operation in which a completely processed substrate is carried out from a process chamber  140 .  
         [0044]     Advantageously, the first robot  150 A may transfer a substrate from and between two process chambers within a narrow area. As will be more evident form the description that follows, this is accomplished by extending an arm of the robot without rotating the robot at its base. Furthermore, the first robot  150 A may be employed in a very small sized loadlock chamber despite the fact that it comprises two substrate supports.  
         [0045]     Referring now to  FIG. 2  through  FIG. 4 , the first robot  150 A is a multi-jointed frog-leg type of robot having a base  160  comprising an arm actuator  162 , an arm unit  164  including a first arm  166  and a second arm  168 , and the dual blade  170 A. The first and second arms  166  and  168  are connected to the arm actuator  162  so as to each be rotatable in a horizontal plane. Note, that the first substrate support  172 A and the second substrate support  174 A of the dual blade  170 A support two substrates, respectively, in the same plane. The dual blade  170 A also has a fixture  176  connected to a third joint  186  disposed on an end of the second arm  168 . The substrate supports  172 A and  174 A are disposed on opposite sides of the fixture  176 . Each substrate support is C-shaped so that it supports the bottom of a substrate along an outer peripheral part thereof. The single substrate transfer apparatus  114  and the second robot  150 B each have a straight blade that will not interfere with the C-shaped wafer supports  172 A,  174 A of the dual blade  170 A while a substrate is being transferred from either the single substrate transfer apparatus  114  or the second robot  150 B to the first robot  150 A. Also, a chuck may also be installed on the blade  170 A for securing a substrate to the blade. The chuck may be a vacuum line through which a vacuum can be exerted on the substrate or a clamp for mechanically clamping an edge of a substrate to the blade.  
         [0046]     The first, second and third joints  182 ,  184  and  186  of the dual wafer transfer apparatus  150 A are respectively controlled by driving motors  188   a,    188   b  and  188   c  of the actuator disposed in the base  160 . The joints  182 ,  184  and  186  are connected to the driving motors through a transmission mechanism. As an example, the transmission mechanism comprises one or more pulleys  190   a  and belts  192  connected to bearings  194 . Preferably, the driving motors  188   a,    188   b  and  188   c  are independently controllable to independently control the rotation of the first arm  166  about the rear end thereof, the second arm  168  about the rear end thereof, and the blade  170  about the fixture  176  thereof so that the arm unit  164  can be moved between a fully retracted position ( FIG. 5 ) and an extended position. Note, although two driving motors are being shown and described as controlling the relative rotations of the first and second arms  166 ,  168 , respectively, a single driving motor ( 188   a ) can be used to control the rotations of the first arm and second arms  166 ,  168 . Also, an elevator  161  is connected to the base  160  for moving the arm unit  164  up and down.  
         [0047]     The first joint  182  connects the base  160  with the first arm  166 . The second joint  184  connects the first arm  166  with the second arm  168 . The third joint  186  connects the second arm  168  with the blade  170 . Each of the joints  182 ,  184  and  186  comprises a bearing  194  connected to the transmission mechanism such that each joint receives power from a respective one of the driving motors  188   a,    188   b  and  188   c.    
         [0048]     The driving motors  188   a,    188   b  and  188   c  of the dual wafer transfer apparatus  150  are programmed, according to kinematic equations of the arm unit  164 , to position the arms  166 ,  168  and blade  170  at desired locations. The program can be stored in a data memory device of a microprocessor (programmable controller) that provides signals for operating the driving motors  188   a,    188   b  and  188   c.    
         [0049]     The multi-chamber system  100  can be enlarged by extending the transfer passage  120 , installing an additional dual substrate transfer robot  150 A at the end of the extended transfer passage  120 , and installing at least one new process chamber adjacent the newly installed robot, as shown in  FIG. 21 . As is clear from this figure, the multi-chamber system  100  makes it easier to add a process chamber than a conventional centralized multi-chamber system. Also, the multi-chamber system  100  is both narrower and shorter than a comparable conventional centralized multi-chamber system, i.e., is more compact. Thus, the multi-chamber system  100  according to the present invention takes up less area in the manufacturing facility.  
         [0050]     Although the present invention has been described so far as comprising two substrate transfer robots installed in the transfer passageway  120  and five or more process chambers connected to the transfer passageway  120 , the present invention is not so limited. Rather, the multi-chamber system according to the present invention may have various configurations as illustrated in FIGS.  20 ( a )- 20 ( f ). For example, the multi-chamber system according to the present invention may comprise only one substrate transfer robot  150  in the transfer passageway  120 , and one to three process chambers  140  disposed around the transfer passageway  120 , as shown in FIGS.  20 ( a )- 20 ( c ) and  20 ( f ). Alternatively, the multi-chamber system according to the present invention may comprise two transfer passageways  120  in which respective substrate transfers robots  150  are disposed, and one or two process chambers  140  disposed around each transfer passageway  120 , as shown in FIGS.  20 ( d ) and  20 ( e ).  
         [0051]     The operation of the multi-chamber system  100  of  FIG. 1  will now be described.  
         [0052]     The loading of a substrate into a process chamber  140  by the first robot  150 A will now be described with reference to  FIG. 5  through  FIG. 8 . As shown in  FIG. 5 , the first robot  150 A starts from a completely retracted position (standby position) in which the first and second arms  166  and  168  and the blade  170 A are aligned in the same direction. Next, as shown in  FIG. 6 , a substrate W 1  is placed on the first support  172   a  of the blade  170 A adjacent the index station  110  by the single substrate transfer apparatus  114 .  
         [0053]     The arms  166 ,  168  are extended to the positions shown in  FIG. 7  and the blade  170 A is rotated a predetermined angle so that the first robot  150 A places the substrate W 1  at a loading position in a process chamber  140 . The substrate WI may be lifted from the first support  172 A in the process chamber  140  by means of a substrate lifting device (a typical device having three lift pins—not shown). Next, the first robot  150 A is completely retracted to the standby position outside of the process chamber  140 , as shown in  FIG. 8 . The substrate W 1  is then set on a substrate stage of the process chamber  140  (by lowering the lift pins) or is otherwise prepared for processing in the process chamber  140 .  
         [0054]     The exchanging of an unprocessed substrate with a processed substrate will now be described with reference to  FIG. 9  through  FIG. 14 .  
         [0055]     An unprocessed substrate W 2  is placed the first substrate support  172 A of the blade  170 A by the single substrate transfer apparatus  114 . Once the substrate WI has been processed in the process chamber  140 , the first gate  142  leading into the chamber  140  is opened and the second support  174 A of the blade  170 A is extended through the first gate  142  to the position shown in  FIG. 10 . Then, the processed substrate W 1  is placed on the second support  174 A by the substrate lift device (not shown), and the first robot  150 A is retracted to the standby position within the transfer passageway  120 , as shown in  FIG. 11 .  
         [0056]     Next, the arms of the first robot  150 A are extended to the position shown in  FIG. 12  and the blade  170 A is rotated such that the first robot  150 A places the unprocessed substrate W 2  at the loading position in the process chamber  140 . The substrate W 2  may be lifted from the first support  172 A by the substrate lifting device of the process chamber.  
         [0057]     Again, the first robot  150 A is retracted to the standby position, as shown in  FIG. 13 . Note, however, that as the arms are retracted the blade  170 A is rotated in reverse (in the clockwise direction (a) in the figure) to position the second support  174 A adjacent the index station  110 . More specifically, the blade  170 A is rotated  180  degrees, so that the processed substrate W 1  is located at an unloading position facing the index station  110 .  
         [0058]     Finally, the processed substrate WI is delivered to the single substrate transfer apparatus  114  ( FIG. 14 ). From there, the processed substrate WI is unloaded from the single substrate transfer apparatus  114  into a FOUP  116 .  
         [0059]     The transferring of a substrate from the first robot to a second robot will now be described with reference to  FIG. 15  through  FIG. 18 . A substrate W 1  is placed on the first support  172 A of the first robot  150 A adjacent the index station by the single substrate transfer apparatus  114  ( FIG. 15 ). The blade  170 A is rotated  180  degrees such that the substrate W 1  is disposed adjacent the second robot  150 B. At that time, arm unit  164  is rotated clockwise to the position shown in  FIG. 16 . The arms  166 ,  168  of the first robot  150 A are then extended such that the first support  172 A of the first robot  150 A is disposed over the first support  172 B of the second robot  150 B, as shown in  FIG. 17 . Then the arm unit  164  of the first robot  150 A is moved down by the elevator  161  to insert the first support  172 B of the second robot  150 B within the first support  172 A of the first robot  150 A and thereby receive the substrate W 1  ( FIG. 18 ). Obviously, the transferring of the substrate from the second robot  150 B to the first robot  150 A is carried out in a manner similar to that described above.  
         [0060]     A second embodiment of a multi-chamber system  200  according to the present invention is illustrated in  FIG. 19 . The multi-chamber system  200  includes an index station  210 , a transfer passageway  220 , process chambers  240 , and dual substrate transfer apparatuses  250  each of which has the same structure and function as that of the first embodiment of  FIG. 1 . However, in the second embodiment, a single substrate transfer apparatus  214  for loading/unloading a substrate into/from a FOUP is installed in the transfer passageway  220 . Alternatively, a dual transfer apparatus can be used in place of the single substrate transfer apparatus  214 . One end of the transfer passageway  220  abuts the index station  210 . A plurality of FOUPs are disposed on respective FOUP openers  212  of the index station  210 .  
         [0061]     Furthermore, the multi-chamber system  200  includes vacuum loadlock chambers  230  connected to both sides of the transfer passageway  220 , and vacuum process chambers  240  connected to each of the loadlock chambers  230 . A dual substrate transfer apparatus  250  is disposed in each loadlock chamber  230 .  
         [0062]     More specifically, each loadlock chamber  230  is connected to two respective process chambers  240  so as to be shared thereby. The loadlock chamber  230  allows a substrate to move between the transfer passageway  220  and the process chambers  240  while ultra-high vacuum conditions are maintained in the process chambers  240 . The dual substrate transfer apparatus  250  can transfer a substrate between the transfer passageway  220  and the two process chambers  240  connected to the loadlock chamber in which the apparatus  250  is disposed. Although this embodiment has been described as having a loadlock chamber shared by only two process chambers, the present invention is not so limited. Rather, each loadlock chamber can be shared by three or more process chambers.  
         [0063]     In any case, each loadlock chamber  230  has a first gate  232 . The first gate  232  is selectively openable and closable for allowing a substrate to pass in and out of the loadlock chamber  230  between the loadlock chamber  230  and the transfer passageway  220 . Each process chamber  240  has second gate  242 . The second gate  242  is selectively openable and closable for allowing a substrate to pass between the loadlock chamber  230  and the process chamber  240 . The gates  232  and  242  are slit valves comprising slots, which are well known in the art and will not be described in further detail. When the second gate  242  is opened to allow a substrate to be transferred between the loadlock chamber  230  and the process chamber  240 , a vacuum generating device (not shown) connected to the loadlock chamber  230  creates a vacuum in the loadlock chamber  230  to prevent a rapid pressure change from occurring in the process chamber  240 . The vacuum pressure generating device is a well known device comprising a vacuum pump, and will not be described in further detail.  
         [0064]     Each dual substrate transfer apparatus  250  installed in a loadlock chamber  230  includes a dual blade  270  having two substrate supports. The dual substrate transfer apparatus  250  can thus perform a carry-in operation in which a substrate is received from the single substrate transfer apparatus  214  and is carried into a process chamber  240 . The dual substrate transfer apparatus  250  also performs a carry-out operation in which a processed substrate is carried out from the process chamber  240 . Basically, each dual substrate transfer apparatus  250  has the same structure and function as the dual substrate transfer apparatus  150  of the first embodiment and will not be described in further detail.  
         [0065]     A third embodiment of a multi-chamber system  300  according to the present invention is illustrated in  FIG. 22 . The multi-chamber system  300  includes an index station  310 , a transfer passageway  320 , and dual substrate transfer apparatuses comprising first and second robots  350 A and  350 B, which have the same structure and function as those of the first embodiment. However, the third embodiment is characterized in that a substrate station  390  is interposed between the first and second robots  350 A and  350 B. A conventional substrate lift device (typical device having three lift pins) is installed at the substrate station  390 . A substrate is transferred between the first and second robots  350 A and  350 B through the substrate station  390 . The provision of the substrate station  390  in the transfer passageway  320  allows for a separate service area  392  to be offered at both sides of the transfer passageway  320  between respective ones of the process chambers  340 . The service areas  392  allow the system  300  to be checked and serviced.  
         [0066]     Finally, although the present invention has been described above in connection with the preferred embodiments thereof, modifications of the preferred embodiments will become readily apparent to those of ordinary skill in the art. It will thus be appreciated and understood, therefore, that the invention is not limited to those embodiments. Rather, the true spirit and scope of the invention is defined in the appended claims.