Abstract:
A purge load port which is a load port devised with a purging plate and a purging module. The purging plate has inlet nozzles, outlet nozzles and recognizer; and the purging module has an inlet opening, an outlet opening, at least a temperature and humidity sensor, at least a flow meter and at least a pressure sensor. It makes the load port incapable of purging to provide the purging techniques after being devised with purging plate and purging modules, which solves the problem of controlling the cleanness by conventional load port, and thus effectively improves the yield of wafers in microchip fabrication.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a load port, particularly to a load port utilized in microchip fabrication. The load port has the function of purging the pod and therefore reduces contamination during fabrication. 
       BACKGROUND OF THE INVENTION 
       [0002]    Wafer surface contamination control becomes a primary task to improve the yield of wafers for the semiconductor and wafer fabs as well as the manufacturers of other high technologies. During fabricating large size semiconductor wafers, the front opening unified pod (FOUP) is used for storing and transporting the wafers, to separate the large size wafers from the exterior air and to prevent contaminations of the large size wafers. 
         [0003]    The load port operates in coordination with FOUP and other microchip fabrication equipments. It functions as a device to carry and open the door of FOUP so that the fabricating equipment can receive large size wafers for fabricating. Since the interior of FOUP becomes partially vacuumed when the door of FOUP is closed, once the door of FOUP is opened by the load port, the exterior atmosphere air may flush into the FOUP to contaminate the large size wafers, and thus reduces the fabrication yield. 
         [0004]    Therefore, in order to improve the yield of wafer fabrication, the problems of sudden atmosphere air influx caused by opening the door of FOUP have to be resolved to avoid atmosphere air flows into the interior of FOUP. Hence, the load port is further devised to provide a function of purge, which means that the load port itself can supply clean gas to fill in the interior of FOUP, so that the clean gas inside the FOUP flows outward to exterior atmosphere, and thus prevent the current problem of atmosphere air influx. Based on the designs described above, the bottom of FOUP is configured with an inlet nozzle and an outlet nozzle. 
         [0005]    However, the conventional load ports are not provided with purge techniques, and are unable to supply clean gas to fill in the interior of FOUP. Therefore, the present invention provides a purge load port which effectively ensures the cleanness inside the FOUP. 
         [0006]    Furthermore, since the load ports are universal equipments, it is required to operate in coordination with various types of FOUPs. Different manufacturers may manufacture various FOUPs with variant design and specifications, which leads to variant interface configurations. For example, some FOUPs are formed with a recess or notch around the rear bottom, and particularly the recess or notch is configured between two inlet nozzles; and some FOUPs is devised flatly around the rear bottom. Accordingly, if the load port is used to purge a specific FOUP, the load port has to recognize the specific FOUP before determining whether to purge or not. 
       SUMMARY OF THE INVENTION 
       [0007]    In order to resolve the problem existing in conventional load port incapable of purging, the present invention provides a purge load port, which is a load port devised with a purging plate and a purging module. The load port has a frame erected vertically and the purging module is configured to rack on a side of a lower portion of the frame, and at the top of the lower portion, the load port is formed with a bench board to which the purging plate is mounted; and the frame is set over the bench board to form an accommodating space; wherein the purging plate has an inlet nozzles and an outlet nozzles, both of which are installed on the purging plate, and the inlet nozzle and the outlet nozzle are connected to the purging module. 
         [0008]    The purging module has a inflation piping each of which is connected to an corresponding inlet nozzle on the purging plate by one end of the inflation piping, therefore the multiple inlet nozzles are clustered at an inlet opening by means of multiple inflation pipings; a exhaust piping, each of which is connected to a corresponding outlet nozzle on the purging plate by one end of the exhaust pipings, therefore the multiple outlet nozzles are clustered at an outlet opening by means of multiple exhaust pipings; a temperature and humidity sensor which is configured within a distance of 2 meters from the outlet opening; a flow meter which is used to measure the amount of the gas flow flowing through the flow meter; and a pressure sensor which is used to measure the pressure of the gas flowing through the pressure sensor. 
         [0009]    In order to resolve the problem existing in conventional load port incapable of purging, the present invention further provides a purge load port, which is a load port devised with a purging plate and a purging module. The load port has a frame erected vertically and the purging module is configured to rack on a side of the frame in a lower portion of the load port, and at the top of the lower portion, the load port is formed with a bench board to which the purging plate is mounted; and the frame is set over the bench board to form an accommodating space; wherein the purging plate has: an inlet nozzles and an outlet nozzles both of which are installed on the purging module, and a recognizer which is configured on the purging plate, and the recognizer can be in an actuating state, wherein the actuation of the actuating state determines the purging module to initiate inflation or exhaust. The load port provided by the present invention is based on the conventional load port and is further devised with the purging plate according to the present invention, so that the load port which is incapable of purging can be advanced to have purging function. Therefore, the utilization rate of the load port is effectively improved. It not only reduces the cost of fabrication, but also improves the yield of wafers in the microchip fabrication. 
         [0010]    The load port according to the present invention can be further configured with a purging module, and the load port achieves better cleaning performance by means of the elements of various sensors configured in the purging module. 
         [0011]    The load port according to the present invention is further provided with a recognizer module having a switch element, which can further recognize different types of FOUP and accordingly determine whether to initiate the function of purging. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of the load port according to the present invention; 
           [0013]      FIG. 2A  is a front view of the purging plate of the load port according to the present invention; 
           [0014]      FIG. 2B  is a rear view of the purging plate of the load port according to the present invention; 
           [0015]      FIG. 3  is a perspective view of a front opening unified pod; 
           [0016]      FIG. 4  is a flowchart showing the purging process executed by the load port according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Firstly, refer to  FIG. 1  showing a perspective view of the load port according to the present invention. As shown in  FIG. 1 , the load port  1  has a frame  11  which is erected vertically. The frame  11  has a first side  16  which is further divided into a lower portion  12  and an upper portion  17  which forms a accommodating space  14  for front opening unified pod (FOUP)  4 , wherein another side of the accommodating space  14  in the upper portion  17  is an access opening  15 . Furthermore, the lower portion  12  of the load port  1  is devised with a purging module  3 . At the top of the lower portion  12 , the load port  1  is formed with a bench board  13  over the space accommodating the purging module  3  in the lower portion  12 . A moveable purging plate  2  is connected to a driving device  24 , and the purging plate  2  together with the driving device  24  are mounted to the bench board  13 . When the purging plate  2  contacts with the FOUP  4  and is fixed, the purging plate  2  can be moved locally toward the access opening  15  by the driving device  24  to make the door  44  of the FOUP  4  to contact with the access opening  15 , so that the load port  1  can open the door  44  of the FOUP  4 ; wherein the driving device  24  is configured on one end of the purging plate  2  near the first side  16  of the frame  11 . 
         [0018]    Next, refer to  FIGS. 2A and 2B  showing a front view and a rear view of the purging plate of the load port according to the present invention. As shown in  FIG. 2A , the purging plate  2  includes two inlet nozzles  21  protruding from the purging plate  2  and two outlet nozzles  22  protruding from the purging plate  2 ; and the inlet nozzles  21  and the outlet nozzles  22  are configured on the periphery of the purging plate  2 . As shown in  FIG. 2B , Each of the protruding inlet nozzles  21  is connected to the inflation piping  5 ; and according to an embodiment of the present invention, each of the inlet nozzles  21  is connected to a corresponding first end  51  of the inflation piping  5  respectively. Each of the protruding outlet nozzles  22  is connected to the exhaust piping  6 ; and according to an embodiment of the present invention, each of the outlet nozzles  22  is connected to a corresponding first end  61  of the exhaust piping  6  respectively. Furthermore, according to a preferred embodiment, the two inlet nozzles  21  are configured on the same side of the purging plate  2 . For example, the two inlet nozzles  21  are configured on the same side near the driving device  24 , while the two outlet nozzles  22  are configured on the same side, such as the side of the purging plate  2  opposite to the side near the driving device  24 . Moreover, a recognizer  23  is further configured on the purging plate  2 , which is used to recognize the type of FOUP  4 . According to a preferred embodiment, the recognizer  23  is installed on the driving device  24 ; and the recognizer  23  is a switch element controlled by contact pressure to be switched on or switched off. 
         [0019]    Next, refer to  FIG. 3  showing a perspective view of a FOUP. As shown in  FIG. 3 , when the load port  1  carries the FOUP  4 , the FOUP  4  is accommodated in the accommodating space  14  over the purging plate  2 . The FOUP  4  includes two inlet valves  41  and two outlet valves  42 . Each of the inlet valves  41  is connected to the corresponding inlet nozzle  21 ; and each of the outlet valves  42  is connected to the corresponding outlet nozzle  22 . Furthermore, when the bottom  45  of the FOUP  4  is a flat plane, the bottom  45  should press the recognizer  23  configured on the driving device  24  simultaneously, therefore the recognizer  23  is switched on. In addition, when the bottom  45  of the FOUP  4  is notched to form a recess region, the bottom  45  should not press the recognizer  23  configured on the driving device  24  simultaneously, therefore the recognizer  23  is maintained in the “off” state. According to an embodiment of the present invention, each of the inlet vales  41  of FOUP  4  is connected to the corresponding inlet nozzle  21  as well as each of the outlet valves  42  of FOUP  4  is connected to the corresponding outlet nozzle  22 ; meanwhile, the recognizer  23  is in the “on” state. Under the circumstances, the load port  1  will initiate the purging function, and operate to fill in the gas into the interior of the FOUP  4  following the flow direction routed by inflation piping  5 , each of the inlet nozzles  21 , and each of the inlet valves  41 , to inflate the FOUP  4 ; in the meantime, the gas inside the FOUP  4  is exhausted out from the interior of FOUP  4  following the flow direction routed by exhaust piping  6 , each of the outlet nozzles  22 , and each of the outlet valves  42 . However when the recognizer  23  is in the “off” state, the load port  1  will not initiate the purging function. 
         [0020]    Next, refer to  FIGS. 3 and 4 .  FIG. 4  is a flowchart showing the purging process execute by the load port according to the present invention. First, the clean gas  33  fills in through a supply of gas  34  configured in of the purging module  3 . At the same time, a inlet pressure sensor  36  configured in the purging module  3  is used to measure the pressure of the flow-in clean gas  33 , and the inflow/outflow of clean gas  33  is controlled by an inlet switch  35 . Next, a needle valve  37  is used to regulate the amount of the clean gas  33 , and then a flow meter  38  is used to measure the amount of clean gas  33 , and a filter  39  is further used to filtrate the clean gas  33 . Ultimately, the clean gas  33  arrived at inlet opening  31 . At that time, the clean gas  33  is passed from the two inlet nozzles  21  respectively connected to the second end  52  of the inflation piping  5 , and then the clean gas  33  is further filled into the interior of FOUP  4  through the inlet valve  41  connected to the two inlet nozzles  21  to perform the cleaning procedure. 
         [0021]    After the inflation inside the FOUP  4  through the inlet valve  41  and the FOUP  4  needs to exhaust gas, the exhaust gas  310  is passed from the outlet valve  42 , then through the two outlet nozzles  22  connected to the outlet valve  42 , and then to a second end  62  of the exhaust piping  6 , and the exhaust gas  310  is finally arrived at the outlet opening  32 . Next, the temperature and humidity of the exhaust gas  310  is measured by a temperature and humidity sensor  311 . In order to detect the status of the exhaust gas  310  accurately, the temperature and humidity sensor  311  needs to be configured within a distance of 2 meters from the outlet opening  31 . In this way, the temperature and humidity of the exhaust gas  310  can be monitored and measured within this distance range, allowing the error of the measured values to be controlled and kept within ±3%. Next, the exhaust gas  310  is evacuated by means of a vacuum generator  312 . An outlet switch  313  is used to control the inflow/outflow of exhaust gas  310 ; and an outlet pressure sensor  314  is used to measure the gas pressure of the exhaust gas  310 . Ultimately, the exhaust gas  310  is arrived at gas outlet  315  and then exhausted. According to the present invention, by means of the flow meter  38 , the inlet pressure sensor  36 , the temperature and humidity sensor  311 , and the outlet pressure sensor  314  configured in the purging module  3 , the cleanness inside the FOUP  4  is exactly controlled. 
         [0022]    Apparently, the purging module  3  according to the present invention needs to utilize processor device to monitor the cleanness inside the FOUP  4 . For example, a computer (not shown in the drawings) is chosen for monitoring the purging module  3  or the monitoring the measured values provided by purging module  3 . When any measured value is out of the predetermined standard range, the computer will alarm, e.g., computer communication system warning message, buzzer phone or warning light, to exactly control the cleanness inside the FOUP  4 . 
         [0023]    According to the load port  1  according to the description above, once the conventional load port without the purging function is devised with the purging plate  2  and purging module  3 , the load port will be given the function of purging. In this way, it will reduce the contamination inside the FOUP  4  so that to minimize the failure rate of wafers. Furthermore, by devising the recognizer module, the load port can recognize different types of FOUP, and then determine whether to execute the purging function or not. In view of the above description, the load port  1  according to the present invention can not only reduce the cost of fabrication equipments but also improve the yield of wafers of the microchip fabrication, leading to contributions for the related industry.