Abstract:
A high-pressure polishing apparatus and method comprising a condenser having high-pressure nozzles for ejecting a solution on the polishing pad to perform a conditioning, thereby preventing damage to the wafer and destruction of the diamond condenser due to a larger force applied on the diamond condenser in order to obtain a better status of polishing pad. The present invention can be applied to a conventional machine.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a polishing apparatus and method and, more particularly, to a high-pressure polishing apparatus and method, in which the dopants deposited in the polishing pad are easily removed, thereby preventing damage to the diamond and wafer from the conventional process.  
         [0003]     2. Description of the Prior Art  
         [0004]     Semiconductor manufacturing has become increasingly complex, requiring numerous, complex process steps. During processing, the surface of the wafer does not remain planar. A conventional semiconductor polishing apparatus typically uses chemical-mechanical processing or chemical-mechanical planarization (“CMP”). The CMP apparatus is used to polish silicon wafers to a mirror surface.  
         [0005]     Generally, chemical mechanical polishing is widely used in the manufacturing process of semiconductor devices to obtain smooth and even surfaced wafers. Chemical mechanical polishing (CMP) is one accepted method of planarization. This planarization method typically requires that the substrate be mounted on a carrier or polishing head. The CMP process is fairly complex, requiring the interaction of the polishing pad, abrasive particles and reactive agent with the substrate to obtain the desired polishing results. After performing CMP for a long time, the ability of channeling the excess slurry to the wafer surface and the ability of catching the particles are reduced. In order to solve these problems, a conditioning process is performed on the surface of the polishing pad. A generally known conditioning method of a polishing pad includes abrading the surface of the polishing pad by a diamond disk, thereby removing the SiO 2  on the polishing pad. However, the diamond is a brittle material. A large down force is needed if a better removing ability is to be obtained, resulting in damage to the diamond and the wafer, thereby increasing the cost.  
         [0006]     In the view of this, the present invention provides a high-pressure polishing apparatus and method in order to overcome the above-mentioned disadvantages.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a high-pressure polishing apparatus and method, in which the material deposited in the polishing pad is removed.  
         [0008]     The present invention also provides a high-pressure polishing apparatus and method, which prevents damage to the diamond on the diamond disk from the conventional process in order to obtain a better removing ability.  
         [0009]     The present invention also provides a high-pressure polishing apparatus and method, which reduces the wafer scrap due to the diamond cracking on the diamond disk.  
         [0010]     The present invention also provides a high-pressure polishing apparatus and method, which extends the lifetime of the diamond-polishing disk.  
         [0011]     The present invention also provides a high-pressure polishing apparatus and method, which can be applied on a conventional machine.  
         [0012]     According to one preferred embodiment of the present invention, a high-pressure polishing apparatus is provided, comprising a polishing table having a polishing pad; a polishing slurry inlet positioned on the polishing table for supplying a slurry to the polishing pad; a rotating wafer carrier positioned on the polishing table for mounting and rotating a wafer, thereby contacting a surface of the wafer with the slurry and the polishing pad to perform a Chemical Mechanical Polishing; and a condenser positioned on the polishing table having a plurality of high-pressure nozzles for ejecting a solution on the polishing pad after finishing the wafer polishing, thereby performing a conditioning on the surface of the wafer.  
         [0013]     According to another embodiment of the present invention, a method of performing a high-pressure polishing apparatus is provided, comprising; fixing a polishing pad on a polishing table; placing a wafer on the polishing pad, thereby contacting the wafer surface with the polishing pad; adding a slurry on the polishing pad by a polishing slurry inlet, performing a Chemical Mechanical Polishing until the required polishing level is reached; and placing a condenser on the polishing pad, wherein a plurality of high-pressure nozzles are formed on the condenser corresponding to the polishing pad, wherein the high-pressure nozzles eject a solution on the polishing pad to perform a conditioning on the wafer surface.  
         [0014]     These and other objectives of the present invention will become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment.  
         [0015]     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     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 embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,  
         [0017]      FIG. 1  is a cross-sectional view of a high-pressure polishing apparatus according to an embodiment of the present invention;  
         [0018]      FIG. 1   a  is a top view of nozzles of a condenser according to an embodiment of the present invention;  
         [0019]      FIG. 2  illustrates a high-pressure polishing apparatus for polishing a wafer according to an embodiment of the present invention;  
         [0020]      FIG. 3  shows a high-pressure polishing apparatus used with the conventional diamond polishing apparatus according to a preferred embodiment of the present invention;  
         [0021]      FIG. 4  shows a high-pressure polishing apparatus used with the conventional diamond polishing apparatus having the condenser and the diamond condenser according to a preferred embodiment of the present invention; and  
         [0022]      FIG. 5  shows a high-pressure polishing apparatus used with the conventional diamond polishing apparatus having the condenser and the polishing slurry inlet according to a preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     The present invention can be widely applied in the Chemical mechanical polishing process in semiconductor processing. The preferred embodiment above is only intended to illustrate the present invention; it does not, however, limit the present invention to the specific embodiment. Accordingly, various modifications and changes may be made without departing from the spirit and scope of the present invention, for example, the moving way of the condenser, the angle of nozzles, the type of nozzles, or the chemical agent.  
         [0024]     Refer to  FIG. 1 , a high-pressure polishing apparatus of the present invention is shown. The high-pressure polishing apparatus comprises a polishing table  10 , a polishing slurry inlet  12  positioned on the polishing table  10 , a rotating wafer carrier  14  positioned on the polishing table  10 , and a condenser  16  which is rotated and moved up and down. The polishing table  10  comprises a polishing pad  18  coated with polishing particles and chemical assistant. The polishing slurry inlet  12  supplies a slurry to the polishing pad. The rotating wafer carrier  14  attaches a wafer  20  thereunder, resulting in having the polishing surface face the polishing pad  18 , thereby contacting the surface of the wafer  20  with the slurry and the polishing pad  18  to perform a Chemical Mechanical Polishing. A plurality of high-pressure nozzles, which are symmetrical and the angle can be adjusted between 5 and 90 degrees is provided. As shown in  FIG. 1   a,  which is a top view of nozzles of the condenser according to the present invention. After polishing the wafer  20 , these nozzles emit DI water or chemical solution to eliminate the residual remains on the surface of the polishing pad  18 . This is so-called conditioning. The angle of the nozzles and the pressure of the ejected solution are adjusted depending on the process.  
         [0025]     When performing the Chemical Mechanical Polishing on the wafer according to the present invention, as shown in  FIG. 2 , the rotating wafer carrier  14  is configured to hold a wafer to be polished, resulting in having the front side of the wafer face the polishing pad  18 . The proper slurry is injected between the polishing pad  18  and the surface of the wafer  20  by the polishing slurry inlet  12 . The wafer pressed down on the polishing pad  18  by the rotating wafer carrier  14 , is moving forward in a fixed direction of rotating force (as shown by the movement direction of the arrow in the drawings) and the surface reaction between the slurry and the wafer, thereby performing the polishing, resulting in simultaneously performing the chemical reaction and the Mechanical Polishing. After polishing, the surface of the polishing pad  18  will be glazed, thereby reducing the flowing ability of the slurry to the surface of the wafer through the channel and the ability of catching the polishing particles. Before performing the next polishing, conditioning is performed on the polishing pad  18  using the condenser  16 . The polishing pad  18  is moved forward in a fixed direction of rotation and is enabled to move right and left (as shown by the arrow in the drawings). The high-pressure nozzle  22  emits DI water or chemical solution, resulting in returning the surface status before polishing. The angle of the high-pressure nozzle can be adjusted between 5 and 30 degrees. The angle and the intensity of the ejected solution are properly changed depending on the process.  
         [0026]     The present invention can be applied to a conventional diamond condenser  24 . A condenser  22  is configured on the conventional apparatus, as shown in  FIG. 3 . The lifetime of the diamond-grinding wheel is extended without applying a large stress to obtain a better removing effect.  
         [0027]     The present invention can be used with the condenser  16  and the diamond condenser  24 , as shown in  FIG. 4 . The movement of the condenser  16  is the same as the diamond condenser  24 . Alternatively, the condenser  16  can be attached to the polishing slurry inlet  12 , as shown in  FIG. 5 . The condenser  16  and the polishing slurry inlet  12  will be moving right and left.  
         [0028]     According to the present invention, a high-pressure polishing apparatus is provided. A condenser is used to perform a conditioning on the surface of the polishing pad. The dopants deposited in the polishing pad are easily removed, thereby preventing damage to the diamond and wafer from the processing.  
         [0029]     The embodiment above is only intended to illustrate the present invention; it does not, however, to limit the present invention to the specific embodiment. Accordingly, various modifications and changes may be made without departing from the spirit and scope of the present invention as described in the following claims.