Abstract:
An in-line oscillating device is essentially composed of an oscillating tank, an oscillating pipe, and an oscillating generator. The oscillating pipe is set in the oscillating tank and connects with a slurry pipe. The oscillating generator for generating ultrasonic waves is mounted on the oscillating tank. Furthermore, the oscillating tank is filled with a medium to transmit the ultrasonic waves generated by the oscillating generator to the oscillating pipe. The in-line oscillating device is suitable to be mounted on any location of the slurry pipe where oscillation is needed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
         [0001]    This application claims the priority benefit of Taiwan application serial no. 90129243, filed Nov. 24, 2001.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates in general to a chemical mechanical polishing (CMP) machine. More particularly, the invention relates to an in-line oscillating device mounted on a slurry pipe in a CMP machine.  
           [0004]    2. Description of the Related Art  
           [0005]    As far as semiconductor processing technology is concerned, surface planarization is an important technology for processing high-density photolithography. A precise pattern transfer is achieved from a plane surface with no drop or no protrusion for avoiding exposure scattering. The planarization technology roughly comprises a spin-on glass (SOG) process and a CMP process. However, after the semiconductor processing technology enters the sub-micron stage, the SOG process does not satisfy the planarization for the sub-micron stage. As a result, the CMP process becomes rarely a global planarization technology for very-large scale integration (VLSI) or ultra-large scale integration (ULSI). In the CMP process, a reagent of slurry is sprayed on a polishing pad and for reacting to an active surface of a wafer, causing the active surface to form an easy-polishing layer. Thereafter, the protrusion area of the easy-polishing layer of the wafer positioned on the polishing pad is polished. Repeating the above chemical reaction and mechanical polishing can form a planar surface. Basically, the CMP process is a planarization technology in which a mechanical polishing principle is applied with an adaptable reagent and abrasive particles.  
           [0006]    Referring to FIG. 1, it is a schematic view illustrating how slurry is transmitted to a CMP machine using a slurry pipe according to prior art. A CMP machine  110  essentially comprises a polishing platform  114 , a polishing pad  112  positioned on the polishing platform  114 , a holder for grasping a polished body, and a slurry pipe  101  for supplying slurry. The slurry pipe  101  are composed of a main pipe  100 , a transmitting pipe  102 , a backflow pipe  104 , a filter  106 , and a peristalsis pump  108 . When the CMP process is performed, the peristalsis pump  108  transmits the slurry from the main pipe  100  to the transmitting pipe  102 . Through the filter  106 , the particles whose size are unfit are filtered out from the slurry being transmitted to the transmitting pipe  102 . Thereafter, the slurry is transmitted to the polishing pad  112 . When the CMP process is not performed, the slurry in the transmitting pipe  102  flows back into the main pipe  100  through the backflow pipe  104 . However, the slurry particles can deposit or stick at a corner of the pipe or at the connecting area between the, backflow pipe  104  and the transmitting pipe  102 .  
           [0007]    In the conventional slurry pipe, the slurry particles can deposit or stick at a corner of the pipe or at the connecting area between the pipes. The deposited chunks of slurry particles are so large that a wafer can be scratched thereby during the CMP process.  
         SUMMARY OF THE INVENTION  
         [0008]    Accordingly, it is an objective according to the present invention to provide an in-line oscillating device. The in-line oscillating device can oscillate the slurry particles in the slurry pipe so that it is difficult for the slurry particles to deposit and stick on the pipe walls. Therefore, the wafer will not be scratched.  
           [0009]    To achieve the foregoing and other objects, the present invention provides an in-line oscillating device essentially composed of an oscillating tank, an oscillating pipe, and an oscillating generator. The oscillating pipe is equipped in the oscillating tank and connects with a slurry pipe. The oscillating pipe is constructed from, for example, a snake-like pipe and two connecting pipes. The both ends of the snake-like pipe connect with the slurry pipe respectively through the connecting pipes. The oscillating generator for generating ultrasonic waves is mounted on the oscillating tank. Moreover, the oscillating tank is filled with a medium, such as deionized water, for transmitting the ultrasonic waves generated by the oscillating generator to the oscillating pipe.  
           [0010]    The oscillating tank of the present invention is provided with a medium inlet for injecting the medium into the oscillating tank and a medium outlet for discharging the medium from the oscillating tank.  
           [0011]    The design of the connecting pipes of the present invention can be determined by the slurry pipe. For instance, the connecting pipes can be a beeline type, a branch type or other types.  
           [0012]    The oscillating generator of the present invention is composed of a controller and at least one oscillator. The controller can control the oscillator to generate ultrasonic waves,  
           [0013]    The in-line oscillating device of the present invention can be mounted on any location of the slurry pipe where oscillation is needed. A variety of connecting pipes can connect the in-line oscillating device and the slurry pipe.  
           [0014]    Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    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. A simple description of the drawings is as follows.  
         [0016]    [0016]FIG. 1 is a schematic view illustrating that slurry is transmitted to a CMP machine using a slurry pipe according to prior art.  
         [0017]    [0017]FIG. 2 is a schematic view illustrating that an in-line oscillating device is mounted upstream before a peristalsis pump according to a preferred embodiment of the present invention.  
         [0018]    [0018]FIG. 3 is a schematic view illustrating that an in-line oscillating device is mounted downstream after a peristalsis pump according to a preferred embodiment of the present invention.  
         [0019]    [0019]FIG. 4 is a schematic view illustrating that in-line oscillating devices are mounted respectively upstream before and downstream after a peristalsis pump according to a preferred embodiment of the present invention.  
         [0020]    [0020]FIG. 5 is a schematic view of an in-line oscillating device according to a preferred embodiment of the present invention.  
         [0021]    [0021]FIG. 6 is a schematic view illustrating that an in-line oscillating devices is mounted to oscillate the connecting area between a transmitting pipe and a backflow pipe according to a preferred embodiment of the present invention.  
         [0022]    [0022]FIG. 7 is a schematic view of an in-line oscillating device oscillating the connecting area between a transmitting pipe and a backflow pipe according to a preferred embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    [0023]FIG. 2 shows a schematic view illustrating that an in-line oscillating device is mounted upstream before a peristalsis pump according to a preferred embodiment of the present invention. FIG. 3 shows a schematic view illustrating that an in-line oscillating device is mounted downstream after a peristalsis pump according to a preferred embodiment of the present invention. As shown in FIG. 2 and FIG. 3, a CMP machine  210  essentially comprises a polishing platform  214 , a polishing pad  212  positioned on the polishing platform  214 , a holder for grasping a polished body, and a slurry pipe  201  for supplying slurry. The slurry pipe  101  are composed, for instance, of a main pipe  200 , a transmitting pipe  202 , a backflow pipe  204 , a filter  206 , a peristalsis pump  208 , and an in-line oscillating device  216 . The in-line oscillating device  216  can generate, for example, ultrasonic waves in which the slurry being transmitted to the in-line oscillating device  216  can be oscillated.  
         [0024]    When a CMP process is performed, the peristalsis pump  208  transmits the slurry from the main pipe  200  to the transmitting pipe  202 . Through the filter  206 , the particles whose size are unfit are filtered out from the slurry being transmitted to the transmitting pipe  102 . Thereafter, the slurry is oscillated by the in-line oscillating device  216 . Finally, the oscillated slurry is transmitted to the polishing pad  212  for performing a CMP process. The in-line oscillating device  216  can be mounted anywhere on the slurry pipe  201  between the filter  206  and the peristalsis pump  208 , or on the slurry pipe  201  downstream after the peristalsis pump  208 . The in-line oscillating device  216  can oscillate the slurry transmitted through the slurry pipe  201  such that it is difficult for the slurry particles to deposit and stick on the pipe walls.  
         [0025]    [0025]FIG. 4 shows a schematic view illustrating that the in-line oscillating devices are respectively mounted upstream before and downstream after a peristalsis pump according to a preferred embodiment of the present invention. As shown in FIG. 4, in order to further improve the problem of the slurry particles being deposited and stuck on the pipe walls, one or more in-line oscillating devices  216  can be mounted respectively upstream before and downstream after the peristalsis pump  208 . By mounting many in-line oscillating devices  216  on the slurry pipe  201 , the slurry in the slurry pipe  201  can be frequently oscillated before transmitted to the CMP machine  210 . Therefore, it is even more difficult that the slurry particles can deposit and stick on the pipe walls.  
         [0026]    [0026]FIG. 5 shows a schematic view of an in-line oscillating device according to a preferred embodiment of the present invention. The in-line oscillating device  216  as illustrated in FIG. 2, FIG. 3, and FIG. 4 essentially comprise an oscillating tank  300 , an oscillating pipe  302 , and an oscillating generator  304 . The oscillating tank  300  is filled with a medium, such as deionized water, in order for transmitting the ultrasonic waves generated by the oscillating generator  304  that is mounted on the oscillating tank  300 . The oscillating pipe  302  is placed in the oscillating tank  300  and connects with the transmitting pipe  202  for conveying slurry. Besides, The oscillating tank  300  is provided with a medium inlet  306  for injecting the medium into the oscillating tank  300  and a medium outlet  308  for discharging the medium from the oscillating tank  300 .  
         [0027]    As shown in FIG. 5, the medium injected into the oscillating tank  300  is for transmitting the ultrasonic waves generated by the oscillating generator  304  to the oscillating pipe  302 . The oscillating pipe  302  is constructed from, for example, a snake-like pipe  302   a  and two connecting pipes  302   b ,  302   c . The both ends of the snake-like pipe  302   a  connect with the transmitting pipe  202  respectively through the connecting pipes  302   b ,  302   c . The connecting pipes  302   b ,  302   c  are beeline type. The snake-like pipe  302   a  is like a spring shape, but it can also be replaced with another pipe with a different shape that is preferred to increase the oscillating time of slurry in the oscillating pipe  302 . The snake-like pipe  302   a  can be a hose or a bellow pipe.  
         [0028]    The oscillating generator  304  is constructed of a controller  304   b  and at least one oscillator  304   a . The controller  304   b  can control the oscillator  304   a  to generate ultrasonic waves. The ultrasonic waves  310  are transmitted pipe  20  oscillating pipe  302  through the medium in the oscillating tank  300  and oscillate the slurry in the snake-like pipe  302   a  and connecting pipes  302   b ,  302   c.    
         [0029]    [0029]FIG. 6 shows a schematic view illustrating that the in-line oscillating devices are mounted to oscillate the connecting area between the transmitting pipe and the backflow pipe according to a preferred embodiment of the present invention. When the CMP process is not performed, the slurry in the transmitting pipe  202  flows back into the main pipe  200  through the backflow pipe  204 . However, the slurry particles can deposit or stick at the connecting area between the backflow pipe  204  and the transmitting pipe  202 . The in-line oscillating device  216  further oscillates the connecting area between the transmitting pipe  202  and the backflow pipe  204  to prevent the slurry particles from being deposited or stuck at the connecting area between the backflow pipe  204  and the transmitting pipe  202 .  
         [0030]    [0030]FIG. 7 shows a schematic view of an in-line oscillating device oscillating the connecting area between a transmitting pipe and a backflow pipe according to a preferred embodiment of the present invention. The medium injected into the oscillating tank  300  is transmitting the ultrasonic waves generated by the oscillating generator  304  to the oscillating pipe  302 . The oscillating pipe  302  is constructed from, for example, a snake-like pipe  302   a  and two connecting pipes  302   b ,  302   c . The both ends of the snake-like pipe  302   a  are connected with the transmitting pipe  202  respectively through the connecting pipes  302   b ,  302   c . The connecting pipe  302   c  is a beeline type. The connecting pipe  302   b  is a branch type, such as a T-type, a Y-type or other types. The connecting pipe  302   b  of a branch type can connect the transmitting pipe  202 , the backflow pipe  204 , and the snake-like pipe  302   a  together. All of the connecting areas, which are between the connecting pipe  302   b  and the transmitting pipe  202 , between the connecting pipe  302   b  and the backflow pipe  204 , and between the connecting pipe  302   b  and the snake-like pipe  302   a , are in the oscillating tank  300 . Therefore, the problem of the slurry particles being deposited or stuck at the connecting areas can be improved.  
         [0031]    In the above-mentioned embodiment, the connecting pipe  302   b  of a beeline type or a branch type is illustrated, but the type of the connecting pipe  302   b  is not limited to that described. The design of the connecting pipe  302   b  of the present invention can be determined by the slurry pipe  201 . A variety of connecting pipe  302   b  can be used to connect the snake-like pipe  302   a  and the slurry pipe  201 . The snake-like pipe  302   a  also can be replaced with another pipe with a different shape that is preferred to increase the oscillating time of slurry in the oscillating pipe  302 .  
         [0032]    To sum up, the in-line oscillating device of the present invention has the following advantages:  
         [0033]    1. The in-line oscillating device of the present invention can oscillate slurry particles in a slurry pipe so that it is difficult for the particles to deposit and stick on a pipe wall so the particles will not deposit and form relatively large chunks of particles.  
         [0034]    2. The in-line oscillating device of the present invention can oscillate slurry particles in a slurry pipe to prevent a wafer from being scratched because the relatively large chunks of particles will not be deposited or stuck.  
         [0035]    3. The in-line oscillating device of the present invention is provided with a snake-like pipe for increasing the oscillating time of slurry in the oscillating pipe, causing the distribution of slurry particles to be relatively uniform.  
         [0036]    4. The in-line oscillating device of the present invention can be provided with connecting pipes of various types, such as a beeline type or a branch type. As a result, the mounting the in-line oscillating device on a slurry pipe is flexible.  
         [0037]    It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.