Abstract:
A pump ring. The pump ring is suitable for a reaction chamber and capable for extracting gas from the reaction chamber in a uniform gas flow rate. The pump ring comprises a ring body and a top ring part located on the ring body. The top ring part is apart from an inner wall of the reaction chamber with a fixed distance. Therefore, a gas-extraction path composed of the reaction chamber, the ring body and the top ring part is unobstructed. Hence, the turbulence flow of the extracted gas can be efficiently suppressed and the problems of the accumulation of the impurities and reaction chamber contamination can be solved.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of Invention  
         [0002]     The present invention relates to a device for a semiconductor process. More particularly, the present invention relates to a pump ring.  
         [0003]     2. Description of Related Art  
         [0004]     Chemical Vapor Deposition (CVD) process is a thin film deposition technology for depositing solid product, which is produced from the reactants (usually is gaseous) in the reaction chamber (such as furnace) through the chemical reaction, on the surface of the wafer. CVD process can be widely applied to most kinds of the formation of the thin film such as conductive thin film, semiconductive thin film or dielectric thin film.  
         [0005]     However, as for CVD process, the formation of the solid product from the gaseous reactants usually accompanies with producing large number of reactant particles and byproducts. Hence, it is necessary to use air-extracting device to extract the gas from the reaction chamber.  
         [0006]      FIG. 1A  is a schematic view diagram showing a pump port and a reaction chamber of a conventional CVD apparatus. The CVD apparatus is a sub-Atmosphere Chemical Vapor Deposition (SACVD) apparatus. In addition,  FIG. 1B  is a cross-sectional view of  FIG. 1A  along line I-I′. As shown in  FIG. 1A  and  FIG. 1B , one side of a reaction chamber  10  possesses a pump port  12 . A pump (not shown) is connected to the reaction chamber  10  through the pump port  12 . While the CVD process is performed in the reaction chamber  10 , the pump extracts the reactant particles and byproducts from the reaction chamber  10 . Moreover, a pump ring  14  is located in the reaction chamber  10 , wherein the periphery of the pump ring  14  and the inner wall  11  of the reaction chamber  10  together form a gas-extraction path  18 . During the gas extraction, the gas extracted from the inner region  20  of the pump ring  14  by the pump through the gas-extraction path  18  and the pump port  12 .  
         [0007]     Nevertheless, typically, there is a protrusion  22  located at each side of the pump port  12  at the inner wall  11  of the reaction chamber  10 . Therefore, gas-extraction path  18  is shrunk between the protrusion  22  and the pump ring  14 . That is, the width d 11  of the gas-extraction path  18  is decreased to be the width d 12  between the protrusion  22  and the pump ring  14  so that the flow rate of the gas extracted from the inner region  20  of the pump ring  14  is changed to cause the turbulence flow between the protrusion  22  and the pump ring  14 . Therefore, the particles are accumulated on the protrusion  22  (that is the accumulation  24  shown in  FIG. 1A ) so that the reaction chamber  10  is contaminated and the problems of apparatus malfunction and damage of the semi-finished product happened.  
       SUMMARY OF THE INVENTION  
       [0008]     Accordingly, at least one objective of the present invention is to provide a pump ring. By using the pump ring, the gas is evenly extracted from the reaction chamber and the turbulence flow is suppressed during the gas extraction procedure. Further, the contamination of the reaction chamber caused by the accumulation of the impurities is decreased.  
         [0009]     To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a pump ring for a reaction chamber. The pump ring comprises a ring body and a top ring part. The top ring part is located on the ring body and the top ring part is apart from an inner wall of the reaction chamber with a distance.  
         [0010]     In the present invention, the ring body is adjacent to the inner wall of the reaction chamber and the top ring part and the ring body are integrated with each other. In addition, the top ring part and the ring body are coaxial and a radius of an outer periphery of the top ring part is smaller than a radius of an outer periphery of the ring body.  
         [0011]     The present invention also provides a pump ring for a reaction chamber, wherein an inner wall of the reaction chamber possesses a plurality of protrusions. The pump ring comprises a ring body and a top ring part. The top ring part is located on the ring body, wherein a plurality of recessions are located on the top ring part so that the top ring part is apart from the protrusions on the inner wall of the reaction chamber with a distance.  
         [0012]     In the present invention, the ring body is adjacent to the inner wall of the reaction chamber and the top ring part and the ring body are integrated with each other.  
         [0013]     The present invention further provides a pump ring for a reaction chamber, wherein an inner wall of the reaction chamber possesses a plurality of protrusions. The pump ring comprises a ring body and a top ring part located on the ring body. The top ring part and the ring body are coaxial and a first radius of an outer periphery of the top ring part is smaller than a second radius of an outer periphery of the ring body so that the top ring part is apart from the protrusions on the inner wall of the reaction chamber with a distance.  
         [0014]     In the present invention, the ring body is adjacent to the inner wall of the reaction chamber. Moreover, the top ring and the ring body are integrated with each other. The pump ring of the present invention is apart from the reaction chamber with a distance so that the turbulence flow can be efficiently suppressed and the laminar flow window is increased. Hence, the accumulation of the impurities is decreased and the reaction chamber contamination problem can be solved.  
         [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.  
         [0017]      FIG. 1A  is a schematic view diagram showing a pump port and a reaction chamber of a conventional CVD apparatus.  
         [0018]      FIG. 1B  is a cross-sectional view of  FIG. 1A  along line I-I′.  
         [0019]      FIG. 2A  is a schematic top view diagram of a pump ring of one of the preferred embodiment according to the present invention.  
         [0020]      FIG. 2B  is a cross-sectional view of  FIG. 2A  along line II-II′.  
         [0021]      FIG. 2C  is a schematic top view diagram illustrating a reaction chamber and the pump ring shown in  FIG. 2A  of one of the preferred embodiment according to the present invention.  
         [0022]      FIG. 2D  is a schematic top view diagram illustrating another reaction chamber and another pump ring of another preferred embodiment according to the present invention.  
         [0023]      FIG. 3  is a schematic top view diagram illustrating the other reaction chamber and the other pump ring of the other preferred embodiment according to the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]      FIG. 2A  is a schematic top view diagram of a pump ring of one of the preferred embodiment according to the present invention.  FIG. 2B  is a cross-sectional view of  FIG. 2A  along line II-II′.  FIG. 2C  is a schematic top view diagram illustrating a reaction chamber and the pump ring shown in  FIG. 2A  of one of the preferred embodiment according to the present invention. Referring to  FIG. 2A  together with  FIG. 2B  and  FIG. 2C , a pump port  212  is located in a reaction chamber  210 . Furthermore, there are several protrusions  222  located on the inner wall  211  of the reaction chamber  210  around the pump port  212  and a pump ring  214  is located in the reaction chamber  210 .  
         [0025]     The pump ring  214  comprises a ring body  215  and a top ring part  216  located on the ring body  215 . The top ring part  216  includes several recessions  223 . After the pump ring  214  is disposed in the reaction chamber  210 , the ring body  215  is adjacent to the inner wall  211  of the reaction chamber  210  and the top ring part  216  and the inner wall  211  of the reaction chamber  210  together form a gas-extraction path  218 . That is, gas can flow between the inner region  220  of the pump ring  214 , the gas-extraction path  218  and the pump port  212 . In addition, the recessions  223  of the top ring part  16  are located one-by-one correspondingly to the protrusions  222  on the inner wall  211  of the reaction chamber  210 . Therefore, the width d 22  of a portion of the gas-extraction path  218  around the protrusions  222  is approximately equal to the width d 21  of the gas-extraction path  218  other than the portion around the protrusions  222 . Hence, the width of the gas-extraction path  218  is uniform so that the turbulence flow caused by uneven path width can be suppressed.  
         [0026]      FIG. 2D  is a schematic top view diagram illustrating another reaction chamber and another pump ring of another preferred embodiment according to the present invention. As shown in  FIG. 2D , there are protrusions  226 , other than the protrusions  222 , on the inner wall  211  of the reaction chamber  210 . In order to avoid the gas-extraction path  218  from being shrunk because of the protrusions  226 , the top ring part  216  possesses several recessions  217  located one-by-one correspondingly to the location of the protrusions  226 . Hence, the width d 25  of a portion of the gas-extraction path  218  around the protrusions  226  is approximately equal to the width d 21  of the gas-extraction path  218  other than the portion around the protrusions  226 . That is, the width of the gas-extraction path  218  is uniform so that the turbulence flow caused by uneven path width can be suppressed.  
         [0027]     Comparing with the reaction chamber  210  shown in  FIG. 2C , there exist extra protrusions  226  on the inner wall  211  of the reaction chamber  210  shown in  FIG. 2D . The top ring part  216  shown in  FIG. 2D  further comprises recessions  227  located one-to-one correspondingly to the protrusions  226 . The width d 25  of the gas-extraction path  218  between the protrusion  226  and the recession  227  is approximately equal to the width d 21  between the top ring part  216  and the inner wall  211  of the reaction chamber  210 . That is, the width of the gas-extraction path  218  is uniform so that the turbulence flow caused by uneven path width can be suppressed.  
         [0028]     Notably, in the reaction chamber  210 , the pump ring  214  described in each embodiment above is apart from the inner wall  211  of the reaction chamber  210  with a fixed distance (a fixed path width). That is, the gas-extraction path  218  composed of the top ring part  216  and the inner wall  211  of the reaction chamber  210  possesses a fixed path width. Therefore, the turbulence flow of the extracted gas caused by uneven path width can be suppressed.  
         [0029]      FIG. 3  is a schematic top view diagram illustrating the other reaction chamber and the other pump ring of the other preferred embodiment according to the present invention. As shown in  FIG. 3 , a pump port  312  is located in a reaction chamber  310  and a pump ring  314  is located in the reaction chamber  310 .  
         [0030]     The pump ring  14  comprises a ring body  315  and a top ring part  316  placed on the ring body  315 . After the pump ring  314  is placed in the reaction chamber  310 , the ring body  315  of the pump ring  314  is adjacent to the inner wall  311  of the reaction chamber  310 . Furthermore, the top ring part  316  and the inner wall  311  of the reaction chamber  310  together form a gas-extraction path  318 . That is, gas can flow between the inner region  320  of the pump ring  314 , the gas-extraction path  318  and the pump port  312 . In addition, the width d 21  of the gas extraction path  318  is fixed. That is, the distance between the outer periphery of the top ring part  316  and the inner wall  311  of the reaction chamber  310  is fixed to be d 21 . Moreover, there exist protrusions  322  at the inner wall  311  of the reaction chamber  310  around the pump port  312  and the width of the gas-extraction path  318  around the protrusions  322  is labeled as d 22 .  
         [0031]     The reaction chamber  310  mentioned above can be, for example but not limited to, SACVD apparatus. The remaining gas after the CVD process is performed is extracted from the inner region  320  of the pump ring  314  in the reaction chamber  310  by pump through the gas-extraction path  318  and the pump port  312 .  
         [0032]     Since the width of the gas-extraction path  318  is decreased around the protrusions  322 , the turbulence flow of the extracted gas caused by the changing of the gas flow rate happens. In order to suppress the turbulence flow of the extracted gas, the width d 21  can be properly designed to alleviate the turbulence flow happening around the protrusions  322 . In one preferred embodiment, top ring part  316  and the ring body  315  can be, for example but not limited to, integrated with each other to simplify the manufacturing process of forming the pump ring  314 . Furthermore, the top ring  316  and the ring body  315  are designed to be coaxial to simplify the manufacturing process of forming the pump ring  314 . Basically, a radius of an outer periphery of the top ring part  316  is smaller than a radius of an outer periphery of the ring body  315 .  
         [0033]     As shown in  FIG. 3 , the radius of the outer periphery of the top ring part  316  is fixed and smaller than the radius of the outer periphery of the ring body  315 . Hence, the gas extracted from the inner region  320  of the pump ring  314  can be flowing in relatively wide gas-extraction path  318 . Accordingly, the difference between the width d 21  and the width d 22  around the protrusions  322  is relatively small even can be neglected by comparing to the relatively wide width d 21 . Hence, the turbulence flow of the extracted gas happening around the protrusions  322  can be efficiently alleviated.  
         [0034]     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 descriptions, it is intended that the present invention covers modifications and variations of this invention if they fall within the scope of the following claims and their equivalents.