Patent Publication Number: US-8986019-B2

Title: Connector with air extraction

Description:
BACKGROUND 
     (a) Technical Field 
     This disclosure relates to the field of semiconductor processing and more in particular to connectors to be used in a clean environment 
     (b) Description of the Related Art 
     In semiconductor processing, vertical furnaces are used for batch processing of wafers. In such furnaces, a boat holding a vertical stack of wafers, accommodated in a wafer boat, the wafer boat being supported on a door plate is inserted into the furnace from below. The door plate may be provided with provisions such as a boat rotation mechanism, door plate heating and temperature sensors. These provisions require electrical connections. In the art, such a connection is made through a long flexible cable that hangs in a loop so as to allow for the vertical up and down movement of the door plate. This implies that a significant length of the cable is exposed to an environment immediately below the furnace. As the wafers to be processed are exposed to this environment, this environment is a mini-environment required to maintain clean air circulation. Into this mini-environment a hot batch of wafers is unloaded after completion of processing. As a consequence, the long flexible cable having an isolation mantle and cable guiding means, is regularly exposed to heat radiation. Therefore, the long flexible cable may get heated and outgas, thereby resulting in contamination of the mini-environment and, possibly, contamination of the wafers, which is undesirable. In an attempt to avoid this contamination, the connection through a long flexible cable in a loop was replaced by a connection made through a connector. The connector has a movable connector part mounted on the movable door plate and a fixed connector part. The two connector parts mate and make contact when the door plate is in an upper, sealing position. The cable to the fixed part of the connector can be stationary and has a strongly reduced risk of outgassing and contamination. However, the connector parts, comprising pins that make a sliding movement in sockets during the action of making contact, is appeared to generate particles. Even though the global circulation of filtered air is present in the mini-environment, it appears to be insufficient to prevent the wafers from being contaminated with particles. 
     SUMMARY 
     According to an aspect of the present invention, an electrical connector to be used in a mini-environment of a semiconductor processing tool is provided. The electrical connector comprises a male connector part having pins and a first holder in which the pins are mounted; and a female connector part having sockets and a second holder in which the sockets are mounted, wherein the male connector part and the female connector part are configured to mate with each other, wherein circumferential parts of the first holder and the second holder are dimensioned such that when the male connector part and the female connector part approach each other, the circumferential parts of the first holder and the second holder partially overlap and define a gap between the circumferential parts of the first holder and the second holder until the pins are in contacting engagement with the sockets, and the first holder and the second holder cooperatively form a chamber enclosing the pins and sockets, and wherein at least one of the male connector and the female connector is provided with an air extraction conduit of which one end communicates with the chamber and the other end communicates with a vacuum pump. 
     According to another aspect of the present invention, a method of handling the aforementioned electrical connector is provided. The method comprises disposing the male connector part and the female connector part in a position that the first holder and the second holder overlap each other at least in part; establishing a communication between the chamber and the vacuum pump through the air extraction conduit at least when the pins are in contacting engagement with the sockets, so that an air flow is established through the gap and the chamber in the direction of the vacuum pump to evacuate particles formed by the electrical connector. 
     According to another aspect of the present invention, an electrical connector of a semiconductor processing tool is provided. The electrical connector comprises a male connector part having pins and a first holder in which the pins are mounted; and a female connector part having sockets and a second holder in which the sockets are mounted, wherein the male connector part is configured to mate with the female connector part and wherein at least one of the male connector part and the female connector part has an air extraction conduit of which one end communicates with a vacuum pump and the other end communicates with a space formed between the male connector part and the female connector part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a male connector part according to an exemplary embodiment of the present invention. 
         FIG. 2  is a perspective view of a female connector part according to an exemplary embodiment of the present invention. 
         FIG. 3  is a perspective view of a connector according to an exemplary embodiment of the present invention showing a male and female connector parts in a position that pins of the male connector part start to engage sockets of the female connector part. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Advantages and features of the present invention and methods to achieve them will be elucidated from exemplary embodiments described below in detail with reference to the accompanying drawings. However, the present invention is not limited to exemplary embodiment disclosed herein but may be implemented in various forms. The exemplary embodiments are provided by way of example only so that a person of ordinary skill in the art can fully understand the disclosures of the present invention and the scope of the present invention. Therefore, the present invention will be defined only by the scope of the appended claims. 
     Provided is an electrical connector to be used in a mini-environment of a semiconductor processing tool such as vertical furnace. An exemplary embodiment of the invention will be explained with reference to the drawings. 
       FIG. 1  is a perspective view of a male connector part according to an exemplary embodiment of the present invention. 
     The male connector  100  is provided with a holder  110 . Pin blocks  120  with arrays of pins  130  are mounted in the holder  110 . An air extraction conduit  140  is provided at the center of the holder  110 . One end of the air extraction conduit  140  communicates with a chamber space  150  provided between the pin blocks  120  in the holder  110 . The other end of the air extraction conduit  140  is in communication with a vacuum pump (not shown) through a tube  160 . Electrical connections to sources of electrical energy or to control devices are made through one or more cables  170 . The male connector  100  is mounted, through mounting base  180  on a substantially stationary part of the processing tool 
       FIG. 2  is a perspective view of a female connector part according to an exemplary embodiment of the present invention. 
     The female connector  200  is provided with a holder  210 . Socket blocks  220  with arrays of sockets  230  are mounted in the holder  210 . A chamber space  250  is provided between the socket blocks  220  in the center of the holder  210 . The female connector  200  is mounted through bracket  280  on a movable part of the processing tool. 
     The male connector  100  and the female connector  200  are configured to be able to mate with each other. This implies that each of the pins  130  is able to mate with a corresponding socket  230  and the connector holders  100  and  200  are able to mate with each other. 
       FIG. 3  is a perspective view of a connector according to an exemplary embodiment of the present invention showing a male and female connector parts in a position wherein pins of the male connector part start to engage sockets of the female connector part. Similar parts are indicated with the same reference numerals as in  FIGS. 1 and 2 . The chamber spaces  150  and  250  are positioned opposite to each other and form a common chamber space. The air extraction conduit  140  may have a plurality of parts, e.g. vertical and horizontal parts. An adjustment screw  142  is provided at an intermediate portion of the air extraction conduit  140  so as to adjust the suction amount through the air extraction conduit  140 . One end the air extraction conduit  140  is in communication with the chamber spaces  150 ,  250 . The other end of the air extraction conduit  140  is in communication with a vacuum pump. The air extraction conduit  140  may be provided in the female connector  200  instead of the male connector  100 . The air extraction conduit  140  may be provided in both the male connector  100  and the female connector  200 . 
     Circumferential portions of the holders  110  and  210  are dimensioned such that, in an approaching position of the male and female connectors  100  and  200 , the circumferential portions of the holders  110  and  210  partially overlap and form a narrow gap  310  between them before the pins  130  are contacting the sockets  230 . In this position, the holders  110  and  210  form a chamber  350  that combines and unites the chamber spaces  150  and  250 . Air may be pulled out from the mini-environment space around the connectors  100  and  200 , through successively the gap  310 , the chamber  350 , and the air extraction conduit  140  to the vacuum pump. When the male and female connectors  100  and  200  further approach each other, the pins  130  slide in and contact the sockets  230  and the pins  130  are inserted into the sockets  230  over some distance until the male and female connectors  100  and  200  are in fully mating position. The overlapping length of the circumferential parts of the holders  110  and  210  correspondingly increases. Air extraction may be applied at least over the entire time span in which the pins  130  are in contacting engagement with and slide into the sockets  230  during both the male and female connectors  100  and  200  close or open actions. The pins  130  are said to be in contacting engagement with the sockets  230 , when at least portions (end tips) of the pins  130  are inserted into the sockets  230 . 
     A valve may be provided in the path of the air extraction conduit  140  to the vacuum pump. The valve is in an open position so as to establishing a communication between the chamber and the vacuum pump through the air extraction conduit and established an air flow through the gap and the chamber in the direction of the vacuum pump to evacuate particles formed by the electrical connector at least when the male and female connectors  100  and  200  are moving relative to each other and the pins  130  are engaging with the sockets  230 . The valve may be in a closed position to as to remove communication between the chamber and the vacuum pump when the male and female connectors  100  and  200  are in fully mating position and the male and female connectors  100  and  200  do not move relative to each other, or when the male and female connectors  100  and  200  are completely separated such that the pins  130  are not engaged with the sockets  230  at all. 
     According to an exemplary embodiment of the present invention, a connector having electrical connections of the moving part that is able to avoid contamination of the wafers is provided. 
     Although throughout this disclosure the word “air” has been used, whether or not in combination with other words such as “air extraction”, “air extraction conduit” etc., it will be understood that the minienvironment may comprise another medium such as filtered nitrogen or forming gas or another inert gas and the word “air” is intended to include such alternative gaseous media. 
     In an embodiment, the substantially stationary part of the connector may be mounted spring loaded, so as to ensure that the connector parts can be pressed into a fully mating position. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims or their equivalents.