Abstract:
A sealing device effects a seal between a first member and a second member of a hermetic chamber. The sealing device includes a body having an elongated shape forming a closed loop. The body of the sealing device includes magnetic material and further includes a) a first and a second sealing portions, and b) at least one internal compartment formed by walls undulatingly extending between the first and second sealing portions. A sealing apparatus includes a first member of a hermetic chamber, a second member of the hermetic chamber, and the above sealing device.

Description:
FIELD OF THE INVENTION 
     The present invention relates to hermetic chambers and more particularly to sealing devices and apparatuses for such chambers. 
     DESCRIPTION OF RELATED ART 
     Sealing devices such as sealing rings are typically used to maintain sealing apparatuses such as hermetic chambers airtight, in particular when the pressure of air or other gas inside the chamber is different from that outside or when the chamber contains gas different from that of the outside environment. However, because of the structure, shape, and material of the sealing ring, many hermetic chambers do not achieve the expected sealing result. 
     In the semiconductor industry, there is a continuing effort to increase yield rate by reducing defects caused by particles and contaminants during various stages of semiconductor manufacturing processes. For example, to dry solutions remaining on wafers, a spin dryer, such as that shown in  FIG. 1  within a hermetic chamber comprising a chamber body  110 , a lid  120 , and a sealing ring  130  fastened to the lid  120 , is used. After the chamber is sealed, no environment air should enter into the chamber containing the spin dryer except through a filter such as a Hepa filter. However, when the sealing ring  130  does not function well, environment air with particles  150  can flow into the chamber through a fissure  160  between the sealing ring  130  and the chamber body  110 . 
       FIG. 2  depicts a prior art Kaijo type sealing ring  130  having a lower part  170  in a round shape which more easily generates a fissure  160 . In addition, the shape of the upper part  180  of the sealing ring  130  is more susceptible to accumulating dust and particles which may enter the spin dryer chamber and cause defects on wafers. In addition, the round shape of the upper part  180  makes it very difficult to clean and maintain the sealing ring  130 . 
     SUMMARY OF THE INVENTION 
     A sealing device effects a seal between a first member and a second member of a hermetic chamber. The sealing device comprises a body having an elongated shape forming a closed loop. The body of the sealing device comprises magnetic material and further includes a) a first and a second sealing portions, and b) at least one internal compartment formed by walls undulatingly extending between the first and second sealing portions. 
     A sealing apparatus comprises a first member of a hermetic chamber, a second member of the hermetic chamber, and the above sealing device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention can be obtained by reference to the detailed description of embodiments in conjunction with the accompanying drawing, in which: 
         FIG. 1  (prior art) illustrates a cross sectional view of a prior art hermetic chamber employing a conventional sealing device disposed between the lid and body of the chamber; 
         FIG. 2  (prior art) is a cross sectional view of the conventional sealing device shown in  FIG. 1 ; 
         FIG. 3  illustrates a cross sectional view of a sealing apparatus which comprises a lid and a container of a hermetic chamber employing an embodiment of a sealing device therebetween to effect a seal; 
         FIG. 4A  illustrates an enlarged view of that portion of in  FIG. 3  enclosed within circle A depicting, in cross section, the embodiment of the sealing device and sealing apparatus shown in  FIG. 3 ; 
         FIG. 4B  is an enlarged view of that portion of in  FIG. 3  enclosed within circle A depicting, in cross section, another embodiment of the sealing device and sealing apparatus of the present invention with one internal compartment; 
         FIG. 5  illustrates, in cross section, another embodiment of a sealing device and sealing apparatus of the present invention; 
         FIG. 6  illustrates yet another embodiment of a sealing device and sealing apparatus of the present invention; 
         FIG. 7  illustrates a view of the sealing device from line BB′ in  FIG. 3 ; 
         FIG. 8  illustrates another embodiment of a sealing device and sealing apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIG. 3 , an exemplary embodiment of a sealing apparatus is a hermetic chamber  300  comprising a container  310  which is a first member of the hermetic chamber, a lid  320  which is a second member of the hermetic chamber, and an embodiment of a sealing device  330  which is disposed between the lid  320  and the container  310 . The container  310  can be a chamber portion of a wet bench spin dryer used in semiconductor manufacturing, or of any container or enclosure of a hermetic type which needs to be airtight. The lid  320  can be a lid or cover portion of the wet bench spin dryer, or of any hermetic type container or enclosure which needs to be airtight. 
     The sealing device  330  has a body with an elongated shape forming a closed loop. For example,  FIG. 7  shows the bottom view of the sealing device  330  and the lid  320  in  FIG. 3 . In this embodiment, the sealing device  330  forms a round loop. Ordinary people in the art will understand that a sealing device can form a loop of other shapes such as a rectangular loop. The sealing device  330  comprises silicone, a fluoroelastomer such as VITON, or a flour seal plastic, which is a soft, pliable, or tender seal plastic. Many other elastic materials can be used. In addition, the sealing device  330  comprises magnetic material to increase a sealing effect. 
     As shown in cross section in  FIG. 4A , the sealing device  330  comprises a first sealing portion  430 , a second sealing portion  450 , and an internal compartment  410  formed by walls undulatingly extending between the first and second sealing portions. The outer surfaces of the first sealing portion  430  form an approximately 90 degrees angle  435  with a lower sealing surface  460  of the lid  320 . The second sealing portion  450  has a flat surface  480  to contact with an upper sealing surface  470  of the container  310 . The internal compartment  410  contains compressible material, such as air. The outer surfaces  440  extending between the first and second sealing portions form an undulating shape with a crest  442  and a trough  444 . An internal magnetic compartment  420  disposed in the second sealing portion  450  contains a magnetic material such as NdFeB. 
     In this embodiment, the first sealing portion  430  of the sealing device  330  is attached to the lid  320  by using glue, screws and other means known to those skilled in the art. When the container  310  is in sealing engagement with the lid  320  with the sealing device  330  disposed therebetween, the second sealing portion  450  contacts the container  310  which comprises metal. As a result, the attractive force between the magnetic material in the internal magnetic compartment  420  and the metal in the container  310  improves the sealing effect. Besides, the internal compartment  410  of the sealing device  330  is compressed to certain extent in the sealing engagement. If the internal compartment  410  is strongly compressed, in order to release some compressive material such as air from the internal compartment  410  into the outside of the sealed container such as a spin dryer, there may be some small holes  485  disposed on the walls forming the internal compartment  410 . 
       FIG. 4B  demonstrates another embodiment of the sealing device  490  of the present invention. The sealing device  490  does not have an internal magnetic compartment. Powders of magnetic material such as NdFeB can be blended together with silicone and/or a fluoroelastomer while manufacturing the sealing device  490  to make the resultant sealing ring magnetic. According, a sealing effect can be increased by the attractive force between the sealing device  490  and the container  310  which comprises metal and/or by the attractive force between the sealing device  490  and the lid  320  which comprises metal. 
     In another embodiment of a sealing apparatus illustrated in  FIG. 5 , a lid  510 , which is the first member of a sealing apparatus, can be a cover portion of a wet bench spin dryer used in semiconductor manufacturing, or of any hermetic container or enclosure which needs to be airtight. A container  520 , which is the second member of the sealing apparatus, can be a chamber portion of the wet bench spin dryer, or any hermetic enclosure which needs to be airtight. A sealing device  530  is disposed between the lid  510  and the container  520 . In this embodiment, the sealing device  530  is fastened to the container  520  by using glue, screws and other means known to those skilled in the art. 
     The sealing device  530  comprises a first sealing portion  540 , a second sealing portion  550 , and an internal compartment  570  formed by walls undulatingly extending between the first and second sealing portions. The outer surfaces of the first sealing portion  540  form an approximately 90 degrees angle  555  with an upper sealing surface  525  of the container  520 . The second sealing portion  550  has a flat surface  545  to contact with a lower sealing surface  515  of the lid  510 . An internal compartment  570  contains compressible material, such as air. The outer surfaces  560  extending between the first and second sealing portions form an undulating shape with a crest  562  and a trough  564 . An internal magnetic compartment  575  disposed in the second sealing portion  550  contains a magnetic material such as NdFeB. The lid  510  comprises metal. As a result, the attractive force between the magnetic material in the internal magnetic compartment  575  and the metal in the lid  510  improves the sealing effect. 
     In  FIG. 6 , another embodiment of a sealing device  600  disposes between the lid  510  and the container  520 . The sealing device  600  comprises a first sealing portion  610 , a second sealing portion  620 , and an internal compartment  640  formed by walls undulatingly extending between the first and second sealing portions. The second sealing portion  620  has a flat surface  627  to contact with a lower sealing surface  515  of the lid  510 . In addition, the outer surfaces of the second sealing portion  620  form an approximately 90 degrees angle  625  with the lower sealing surface  515  of the lid  510  when the container  520  is in sealing engagement with the lid  510 . The outer surfaces  630  extending between the first and second sealing portions form an undulating shape with a crest  634  and two troughs  632  and  636 . An internal magnetic compartment  650  disposed in the second sealing portion  620  contains a magnetic material. 
     In  FIG. 8 , another embodiment of a sealing apparatus comprises a first member  810 , a second member  820  with an opening  840 , and a sealing device  830  fastened to the second member  820 . The body of the sealing device  830  can be an elongated loop in a rectangular shape. The second member  820  may enclose a fairly large space where machines, such as a process chamber and a metrology device, can be installed inside. The first member  810  can be a window or a door to the second member  820 . By a screw, a spring, and/or a compressor, the first member  820  can be in sealing engagement with the second member  820  with the sealing device  830  disposed therebetween. 
     Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.