Patent Publication Number: US-2006011300-A1

Title: Device for treating semiconductor substrate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This U.S. non-provisional patent application claims priority under 35 U.S.C. § 119 of Korean Patent Application 2004-55998 filed on Jul. 19, 2004, the entire contents of which are hereby incorporated by reference.  
     BACKGROUND OF THE INVENTION  
      The present invention relates to a device for manufacturing a semiconductor substrate, and more particularly to a device for performing a cleaning process to a semiconductor substrate.  
      A semiconductor device manufacturing process is typically associated with a deposition process in which a thin film layer is formed on a wafer and an etching process in which fine circuit patterns are formed on the thin film layer. Until circuit patterns required on the wafer are formed, the processes are repeated, and many curvatures are formed on the surface of the wafer. As the semiconductor is highly integrated, the line width of the circuit is reduced, and more wires are stacked on one chip and the step difference according to the positions in the chip is increased. The step difference generated by the stacking wires makes uniform coating of the conductor layer in the following process difficult, and problems such as defocus in the photographing process or the like are generated.  
      In order to solve the above problems, a process in which the surface of the wafer is flattened is required. Recently, since the wafer has become larger, a CMP (chemical mechanical polishing) method is mainly used to obtain an excellent flattening rate in a wide range flattening.  
      The CMP equipment has a polishing portion which performs a polishing process to the wafer, and a cleaning portion which performs a cleaning process to the wafer after polishing the wafer. The cleaning process comprises a chemical liquid treating process which etches and ablates contamination materials on the wafer by chemical reactions which uses chemical liquid such as fluorine acid, ammonia, and SC-1 (a liquid mixture of ammonia, hydrogen peroxide, and deionized water), a rinsing process in which the semiconductor wafer which is treated by the chemical liquid is rinsed by using a deionized water, and a drying process in which the wafer is dried finally.  
      Various devices are used to perform the cleaning process. One of such a device comprises a rotational support plate which has a plurality of arms, and support blocks on which a wafer is positioned are installed at the end portions of the arms. The support blocks are positioned on a flat upper surface of the arms, and are fixed by two screws inserted from a bottom of the support plate. The support plate is rotated at a high speed during the process. The loads applied to the engaging portion of the support blocks and the support plate are concentrated on a head portion of the screws during the rotation. Therefore, the screws are frequently damaged, and the operation rate of the equipment is lowered by the frequent changes of the screws.  
      The above-mentioned device can be used in one or plural processes among the chemical liquid treating process, the rinsing process, and the drying process. If the chemical liquid treating process which is processed at a high temperature and the drying process which is processed at an ordinary temperature are processed simultaneously, the screws are more easily damaged by the periodic thermal stress of the screws.  
     SUMMARY OF THE INVENTION  
      The present invention is directed to a substrate treating device which can prevent the damage of members which engage a support plate and support blocks due to the concentrations of loads.  
      A device for treating a semiconductor substrate is provided. This device comprises a rotational support plate in which at least one mounting recess is formed at the periphery thereof. Support blocks are disposed on the periphery of the support plate within the mounting recess for supporting the semiconductor substrate. Each of the support blocks comprises a positioning portion on which the semiconductor substrate is positioned, and an insertion portion which has a shape complementary to the shape of the mounting recess and is disposed under the positioning portion where it is inserted into the mounting recess.  
      Preferably, the mounting recess is formed so as to be extended to the side surface of the support plate and the support block is moved into the mounting recess. At least one portion of the side surfaces which form the mounting recess preferably makes contact with an upper portion of the insertion portion when it is inserted into the mounting recess. The side surface which forms the mounting recess preferably comprises inclined sides and a wider lower portion, and the cross-section of the mounting recess comprises inclined sides and a wider lower portion. The mounting recess preferably comprises an upper portion which has a uniform cross-section and a lower portion which has a uniform cross-section, the cross-section of the lower portion of the mounting recess being wider than that of the cross-section of the upper portion of the mounting recess. The support plate preferably comprises a center portion, and arms which are joined to and extend from the center portion, the mounting recesses being formed in the arms.  
      The device further preferably comprises at least one engaging member which joins the insertion portion and the mounting recess. The engaging member is preferably at least one screw. The engaging member is preferably made of a high temperature polymer, more preferably polyvinyl chloride.  
      The treatment of the semiconductor substrate preferably comprises at least one of a chemical liquid treating process, a rinsing process, and a drying process. Moreover, a device for treating a semiconductor substrate can be provided which comprises a polishing portion which performs a polishing process to the semiconductor substrate and a cleaning portion disposed on a side of the polishing portion, for cleaning the semiconductor substrate on which the polishing process is performed. The cleaning portion can comprise a cleaning device chemically treating and for drying the semiconductor substrate. The cleaning device can further comprise a rotational support plate in which at least one mounting recess is formed at the periphery thereof, support blocks disposed on the periphery of the support plate the mounting recess for supporting the semiconductor substrate, and a nozzle portion which supplies a chemical material onto the semiconductor substrate supported by the support blocks. Each of the support blocks can further comprise a positioning portion on which the semiconductor substrate is positioned, and an insertion portion having a shape complementary to the shape of the mounting recess and disposed under the positioning portion where it is inserted into the mounting recess.  
      moved 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate example embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the drawings:  
       FIG. 1  is a view for schematically showing the structure of a substrate treating device according to a preferred embodiment of the present invention;  
       FIG. 2  is a front view of a cleaning device of  FIG. 1 ;  
       FIG. 3  is a perspective view for showing a support plate and support blocks of  FIG. 2 ;  
       FIG. 4  is a view illustrating a state in which a latch is in a locked position;  
       FIG. 5  is a view illustrating a state in which a latch is in an open position;  
       FIG. 6  is a perspective view illustrating a preferred mounting recess of the support plate and an insertion portion of a support block; and  
       FIG. 7  is a perspective view illustrating another preferred mounting recess of the support plate and an insertion portion of a support block. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numerals refer to like elements throughout the specification.  
      Hereinafter, it will be described about an exemplary embodiment of the present invention in conjunction with the accompanying drawings.  
      In the following embodiments, a substrate treating device comprises a cleaning portion  30  and a polishing portion  40 , and equipment for chemically and mechanically polishing a semiconductor substrate will be described. However, it is an example of preferred embodiments, and the spirit of the present invention can be applied to all devices which have a rotational support plate  100  and a support block which is engaged with the support plate  100  and supports a wafer. For example, the substrate treating device of the present invention can be a device which performs a cleaning process, such as a chemical liquid treating process, a rinsing process, and a drying process, or a device which performs different processes.  
       FIG. 1  is a view for schematically showing the structure of a substrate treating device according to a preferred embodiment of the present invention. Referring to  FIG. 1 , the device comprises a loading/unloading portion  10 , a transferring portion  20 , a cleaning portion  30 , and a polishing portion  40 . Buffer portions  12  in which cassettes for receiving wafers are positioned are disposed in the loading/unloading portion  10 . At least one polishing device is disposed in the polishing portion  40 , and the polishing device  42  has a platen (not shown) to which a polishing pad (not shown) is attached and a polishing head which fixes a wafer and presses the wafer on the polishing pad (not shown). A device for polishing a wafer by using a polishing pad and a polishing head is well known in the art, and explanation of the device is omitted. The number of the polishing devices  42  can be one or a plurality. In the preferred embodiment, two polishing devices are provided.  
      A cleaning portion  30  is disposed on one side of the polishing portion  40 . The cleaning portion has at least one cleaning device  32  and  34 . The cleaning portion  30  performs a chemical liquid treating process, a rinsing process, and a drying process to a wafer to which a polishing process is completed. The chemical liquid treating process is performed by sequentially using a plurality of chemical liquids. For example, the chemical liquid which is used in the chemical liquid treating process can be fluorine acid, ammonia, or SC-1 (a liquid mixture of ammonia, hydrogen peroxide, and deionized water). Two cleaning device  32  and  34  are provided in one polishing device  42 . In the cleaning device  32  adjacent to the polishing device  42 , the chemical liquid treating process can processed by sequentially using a first chemical liquid and a second chemical liquid. In the other cleaning device, a chemical liquid treating process by a third chemical liquid, a rinsing process by deionized water, and a drying process can be performed. The first through third chemical liquid can be one of fluorine acid, ammonia, and SC-1. Although not shown in the figures, a transferring robot for transferring wafers between the polishing device  42  and the cleaning devices  32  and  34  is provided in the polishing portion  40  and the cleaning portion  30 . Differently from the above-described example, one cleaning device can perform the above-mentioned processes, or more cleaning devices can performs one process in one cleaning device. The transferring portion  20  is disposed between the cleaning portion  20  and the loading/unloading portion  10 , and a transferring robot  22  for transferring a wafer is installed in the transferring portion  20 . The structure of the above-described substrate treating device is merely an example of the present invention, the loading/unloading portion  10 , the transferring portion  20 , the cleaning portion  30 , and the polishing portion can be disposed differently form this structure.  
       FIG. 2  is a front view for showing a cleaning device  34  which performs a drying process, and  FIG. 3  is a perspective view for showing the support plate  100  and the support block  200  of  FIG. 2 . Referring to  FIGS. 2 and 3 , the cleaning device  34  has the support plate  100 , the support block  200 , and a nozzle portion  300 . The support plate  100  has a center portion  120  of disc-shape, and a plurality of arms which is extended outwardly from the center portion. According to the present invention, the support plate  100  has four arms which are disposed at a substantially constant angle, each of the rod arms  140  has a rod shape. A rotating shaft  102  rotated by a motor  104  is engaged with the bottom surface of the support plate  100 , and the nozzle portion  300  is disposed at an upper portion of the support plate. The nozzle portion  300  is vertically disposed on one side of the support plate  100 , and has a rotational support shaft  320 . A support arm  340  is horizontally engaged with the tip end portion of the support shaft  100 , and a nozzle  360  for supplying the chemical liquid or the deionized water is connected to the bottom surface of the end of the support arm  340 . The number of the nozzle portions  300  can be one or a plurality.  
      The support block  200  is installed on the upper surface of the end of each of the arm. The support block  200  has a positioning portion  220  on which a wafer is positioned. The positioning portion  220  has a contacting portion  222  which is positioned at the periphery of the wafer and a guide portion  224  which guides the water to a proper position. The contacting portion  222  is flatly formed, and the guide portion  224  is formed such that it is inclined from the end of the contacting portion  222  towards the upper portion. An opening  226  which is penetrated in the radial direction of the wafer is formed at the center portion of the contacting portion  222  and the guide portion  224 . If a peripheral portion of the wafer transferred by the robot is positioned on the guide portion  224 , the wafer moves downwardly along the guide portion  224 , and the periphery of the wafer is positioned on the contacting portion  222 . According to the preferred embodiment of the present invention, the wafer is supported by four support blocks  200 . Selectively, three or more than five arms  140  can be provided, and the wafer can be supported by three or more than five support blocks  200 .  
      A hole  228  which is vertically penetrated is formed at the center portion of the support block  200 , and a fixing member  260  which fixes the wafer positioned on the support block  200  is inserted into the hole  228 . The fixing member  260  has a structure in which the fixing member can be moved upwardly and downwardly by a predetermined distance. The fixing member  260  has a latch  262 , a vertical rod  264  engaged with the latch  262 , and a driving portion which drives the vertical rod  264  upwardly and downwardly. The latch  262  has a hook shape of a large radius of curvature. Preferably, the latch  262  has a shape which corresponds to a predetermined portion of the contacting wafer. A hole  266  is horizontally formed in the vertical rod, and a pivot  268 , which engages the latch  262  and the vertical rod  264 , is inserted into the hole  266 . By the upward and downward movement of the vertical rod  264 , the pivot  268  is moved in the hole  266  by a predetermined distance, and the latch  262  is rotated through the opening  226  formed in the guide portion  224 . By the rotation, the latch  262  is moved between a locking position, at which it makes contact with the side surface and the upper surface of the wafer, and an opening position, at which it is pushed outwardly of the support block  200  through the opening formed in the guide portion.  FIG. 4  is a view for showing a state in which the latch  262  is at the locking position by the downward movement of the vertical rod  264 , and  FIG. 5  is a view for showing a state in which the latch  262  is at the opening position by the upward movement of the vertical rod  264 .  
      The upper surface of the arm  140  is flatly formed, and the support block  200  can be engaged with the upper surface of the arm  140  by screws  280 . However, in this case, when the support plate  100  is rotated at a high speed, the load is concentrated on the screws  280 . If the chemical liquid treating process is performed at a high temperature, the drying process is processed at an ordinary temperature, or the like are periodically processed, the screws  280  are easily damaged by the thermal stress. In order to prevent such damage, in a preferred embodiment, a mounting recess  160  is formed at the peripheral portion of each of the arms  140 , and the support block  200  has an insertion portion  240  which is extended from the lower portion of the positioning portion  220  and inserted into the mounting recess  160 . The mounting recess  160  is formed on the upper surface of the arm  140  and is extended to the side surface of the arm  140 . The mounting recess  160  is arranged lengthwise along the arm  140  such that the longitudinal cross-section is constant, and the insertion portion  240  has a shape corresponding to the mounting recess  160 . As the insertion portion  240  is moved from the end of the arm  140  towards the inner side of the arm  140 , the support block  200  is engaged with the arm  140 . If the insertion portion  240  is inserted into the mounting recess  160 , the support block  200  is fixed to the arm  140  by engaging members. The screws  280  can be used as the engaging members, and a plurality of, preferably at least two, screws  280  can be provided. The screws  280  can be inserted from the bottom surface or the side surface of the arm  140 , and can be inserted from the support block  200 . In another embodiment, one screw  280  can be inserted from the bottom surface of the arm  140 , and another screw can be inserted from the support block  200 . The screws  280  are generally made of PEEK (polyether ether ketone) and are apt to be easily deteriorated. In the preferred embodiment, the screws  280  are made of HT-PVC (high temperature poly vinyl chloride) and are more durable to the effects of heat.  
      The insertion portion  240  of the support block  200  and the mounting recess  160  can be formed in various shapes. Since the insertion portion  240  has a shape corresponding to the mounting recess  160 , only the shape of the mounting recess  160  will be explained. In the state in which the insertion portion  240  is inserted into the mounting recess  160 , at least one portion of side surface which forms the mounting recess  160  makes contact with the insertion portion  240  at the upper portion of the insertion portion  240 .  FIG. 6  depicts the mounting recess  160  formed in the arm  140  and the insertion portion  240  of the support block  200  in  FIG. 3 . Referring to  FIG. 6 , the mounting recess  160  has an opened upper portion, a flat lower surface, and inclined surfaces  162  disposed on both sides. The inclined surfaces  162  is disposed so as to be opposite to each other, and is formed such that the area of the cross-section of the mounting recess  160  is gradually widened at the lower portion thereof. When the support plate  100  is rotated at a high speed, the load is uniformly distributed to the inclined surfaces  162  which make contact with the insertion portion  240  of the support block  200 . Therefore, the load is not concentrated on the screws  280 , and thus the life of the screws can be extended.  
       FIG. 7  is a view similar to  FIG. 6  which shows another example of the shapes of the mounting recess  160  and the insertion portion  240 . Referring to  FIG. 7 , the mounting recess  160  has a upper portion  164  and a lower portion  166 . The upper portion  164  of the mounting recess  160  has a substantially uniform cross-section. The lower portion  166  is disposed under the upper portion  164 , and has a substantially uniform cross-section. The border portion of the upper and lower portions is stepped, and the area of the cross-section of the lower portion  166  is wider than that of the upper portion  164 . When the support plate  100  is rotated at a high speed, the load is uniformly distributed to the stepped portion, and a concentration of the load on the screws  280  can be prevented.  
      The shapes of the mounting recess  160  and the insertion portion  240  of the support block  200  which are shown in  FIGS. 6 and 7  are merely examples of the present invention. The cleaning device  32  in which the chemical liquid treating process is conducted can have the same structure as the cleaning device in which the drying process or the like is performed, or it can have a different structure.  
      According to the present invention, the concentration of the load to the screws which engages the arm of the support plate and the support block during the processes can be substantially reduced, and thus the lowering of the equipment operation downtime due to frequent changes of the screws.  
      Although the present invention has been described in connection with the embodiment of the present invention illustrated in the accompanying drawings, it is not limited thereto. It will be apparent to those skilled in the art that various substitution, modifications and changes may be thereto without departing from the scope and spirit of the invention.