Abstract:
A semiconductor device comprising a plurality of metal wire patterns, each of which includes main fine line patterns, main pad patterns and dummy fine line patterns, wherein an area ratio of the dummy fine line patterns, which are connected to the main pad patterns, to the entire wire patterns is less than 1% and lower than a ratio of the main fine line patterns to the entire wire patterns.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a semiconductor device capable of preventing a corrosion of metal wires and, more particularly, to a semiconductor device capable of preventing a corrosion of metal wires from a chemical mechanical polishing (CMP) process.  
         DESCRIPTION OF THE PRIOR ART  
         [0002]    Generally, wires of a semiconductor device have been formed by using a reactive ion etching (RIE) process. However, as the width of the wires becomes narrower, it is difficult to apply the RIE process to form wires so a damascene technology is introduced. In the damascene technology, a chemical polishing (CMP) process is necessary for an isolation of the wires. Accordingly, the CMP process for the Al or Cu wires is required. Al and Cu have lower hardness than tungsten (W), and also have a very high chemical activity, making the Al and Cu wires very susceptible to corrosion. Since the corrosion of the metal wires is fatal to the reliability of the semiconductor device, such corrosion has to be prevented.  
           [0003]    The CMP process is a key process in forming wires when applying the damascene technology. Since the Al or Cu wire is the electrically and chemically active metal, after the CMP process, a NH 4 OH or HF solution, which is used at the conventional post cleaning process, cannot be used at a post cleaning process so that, if an appropriate chemical cleaner capable of being used at the post cleaning process is not developed, the post cleaning process is performed by using deionized (DI) water.  
           [0004]    When the DI water is used as a post-process cleaner, a fine line, which is connected to a large pad, is more heavily corroded than an adjacent wide line. Since the corrosion is observed at a wafer cleaning process after the CMP process, another cleaning solution has to be used instead of the DI water. Recently, the wires are formed with copper and a low k insulating layer so that a research of the aluminum damascene process is weaker than the copper process. Accordingly, researches of CMP slurry and the post process cleaner are insufficiently developed.  
           [0005]    The basic method for suppressing corrosion is to change a position, in which an oxidation reaction occurs. Namely, it is to use a material, which is electrically and chemically much more active than a material used as the wire, as a sacrificial anode. However, this requires a complicated process in which the sacrificial anode has to be formed at the same pattern with main wires. Also, it is not easy to select metals which are much more active material than aluminum or copper, which is usually used to form the wire.  
         SUMMARY OF THE INVENTION  
         [0006]    It is, therefore, an object of the present invention to provide a semiconductor device capable of preventing corrosion of metal wire patterns formed with aluminum or copper from the chemical-mechanical polishing (CMP) process.  
           [0007]    In accordance with an aspect of the present invention, there is provided a semiconductor device comprising a plurality of metal wire patterns, each of which includes fine line patterns and pad patterns, wherein an area ratio of the fine line pattern to the entire wire patterns is above 1%.  
           [0008]    In accordance with another aspect of the present invention, there is provided a semiconductor device comprising a plurality of metal wire patterns, each of which includes main fine line patterns, main pad patterns and dummy fine line patterns, wherein an area ratio of the dummy fine line patterns, which are connected to the pad patterns, to the entire wire patterns is below 1% and lower than that of the main fine line patterns. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The above and other objects and features of the instant invention will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:  
         [0010]    [0010]FIG. 1 is a schematic diagram showing a formation of metal wire patterns in accordance with a first embodiment of the present invention;  
         [0011]    [0011]FIG. 2 is a schematic diagram showing a formation of metal wire patterns inserting dummy lines in accordance with a second embodiment of the present invention;  
         [0012]    [0012]FIG. 3 is a schematic diagram showing a formation of metal wire patterns inserting dummy lines and large dummy pads in accordance with a third embodiment of the present invention; and  
         [0013]    [0013]FIG. 4 is a schematic diagram showing a formation of metal wire patterns inserting dummy lines and large dummy pad pool in accordance with a fourth embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    Hereinafter, a method for preventing a corrosion of metal wire patterns formed with an aluminum or copper wire from the chemical-mechanical polishing (CMP) process will be described in detail referring to the accompanying drawings.  
         [0015]    In order to basically prevent the corrosion of the metal wires formed with an Al or Cu wire according to the present invention, a dummy pattern, where corrosion can occur instead of a main wire pattern, is additionally inserted to a basic wire pattern. When a fine line pattern of sub-micron size is connected to a large pad pattern, the fine line pattern is easily corroded. This corrosion is a dependence of patterns because the large pad pattern and the fine line pattern are formed with the same material. Particularly, when an area ratio of the fine line pattern to the overall wire patterns including the fine line pattern and the large pad pattern is low, the corrosion easily occurs so that, as a dummy fine line pattern, when an area ratio of the dummy fine line pattern to the entire wire patterns including a fine line pattern, a large pad pattern and the dummy fine line pattern, is larger than an area ratio of the narrow main line to the entire wires, is formed, the corrosion of the fine line pattern can be prevented.  
         [0016]    Two method embodiments for preventing the wire corrosion will be described according to the present invention.  
         [0017]    A first method is to differently form a pattern from the prior pattern. Namely, it is to change an area ratio of the fine line pattern to the entire wire patterns.  
         [0018]    [0018]FIG. 1 is a schematic diagram showing the formation of metal wire patterns including a main fine line pattern  120 , which has to be protected from corrosion, connected to large pad patterns  100  in accordance with a first embodiment of the present invention. After the CMP process of the wire patterns, the corrosion of the main fine line pattern  120  is caused when the main fine line pattern  120 , when a width of the main fine line pattern is below 1 μm, is connected to the large pad patterns  100 . When an area ratio of the main fine line pattern  120  to the entire wire patterns including the large pad patterns  100 , connection pad pattern  110  and the main fine line pattern  120  is approximately above 1%, the corrosion can be prevented. A formula for preventing the corrosion is as follows:  
         ( A /( Ap+Ac+A ))×100)&gt;1%  
         [0019]    where, ‘A’ represents an area of the main fine line pattern  120 , ‘Ap’ represents a gross area of the large pad patterns  100  and ‘Ac’ represents a gross area of the connection pad patterns  110 .  
         [0020]    A second method for preventing the corrosion of the main fine line pattern is to additionally insert a dummy fine line pattern to the basic wire patterns.  
         [0021]    [0021]FIG. 2 is a schematic diagram showing a formation of metal wire patterns using dummy fine line patterns  220  connected to the large pad patterns  200  for preventing a corrosion of the main fine line pattern  230  in accordance with a second embodiment of the present invention.  
         [0022]    Referring to FIG. 2, the dummy fine line patterns  220  are connected to the large pad patterns  200  and formed parallel with the main fine line pattern  230 , which is desired to prevent the corrosion. When an area ratio of the dummy fine line patterns  220  to the entire wire patterns is much lower than an area ratio of the main fine line pattern  230  to the entire wire patterns and is below 1%, the corrosion of the main fine line pattern  230  can be prevented. A formula for preventing the corrosion according to this second embodiment is as follows:  
         ( d /( Ap+Ac+A+d )×100)&lt;1% and,  
           d /( Ap+Ac+A+d )&lt; A /( Ap+Ac+A+d )  
         [0023]    where, ‘d’ represents a gross area of the dummy fine line patterns  220 , ‘Ap’ represents a gross area of the large pad patterns  200 , ‘Ac’ represents a gross area of the connection pad patterns  210  and ‘A’ represents an area of the main fine line pattern  230 . Also, the dummy fine line patterns  220  do not make any electric circuit.  
         [0024]    [0024]FIG. 3 is a schematic diagram showing a formation of metal wire patterns using dummy fine line patterns  340  connected to large dummy pad patterns  330  for preventing the corrosion of a main fine line pattern  320  in accordance with a third embodiment of the present invention of the present invention. The large dummy pad patterns  330  and the dummy fine line patterns  340  do not make any electric circuit.  
         [0025]    A formula for preventing the corrosion of the main fine line pattern  320  is as follows:  
         ( d /( D+d ))×100&lt;1% and,  
         ( d /( D+d ))&lt; A /( Ap+Ac+A )  
         [0026]    where, ‘d’ represents a gross area of the dummy fine line patterns  340  and ‘D’ represents an gross area of the large dummy pad patterns  330 . Also, ‘A’ represents an area of the main fine line pattern  320 , ‘Ap’ represents a gross area of the large pad patterns  300  and ‘Ac’ represents a gross area of connection pad patterns  310 . At this time, the large dummy pad patterns  330  and the dummy fine line patterns  340  are electrically disconnected from the main wire patterns.  
         [0027]    [0027]FIG. 4 is a schematic diagram showing a formation of metal wire patterns using a dummy pad pool  440  and dummy fine line patterns  430 A and  430 B to be used in several modules for the same purpose of preventing corrosion of the main fine line patterns  420 A and  420 B in accordance with a fourth embodiment of the present invention.  
         [0028]    Referring to FIG. 4, in order to prevent the corrosion of the main fine line pattern  420 A in an ‘X’ part, a formula for area ratios is as follows:  
         ( d 1/( D+d 1 +d 2)×100)&lt;1% and,  
         ( d 1/( D+d 1 +d 2)&lt; A 1/( A 1 p+A 1 c+A 1)  
         [0029]    where, ‘d1’ represents a gross area of the dummy line patterns  430 A, ‘d2’ represents a gross area of the dummy line patterns  430 B, ‘D’ represents an area of the dummy pad pool  440 . Also, ‘A1’ represents an area of the main fine line pattern  420 A, ‘A1p’ represents a gross area of the large pad pattern  400 A and ‘A1c’ represents a gross area of connection pad patterns  410 A.  
         [0030]    Also, in order to prevent the corrosion of the main fine line pattern  420 B in a ‘Y’ part, a formula for area ratios in as follows:  
         ( d 2/( D+d 1 +d 2)×100&lt;1% and,  
         ( d 2/( D+d 1 +d 2)&lt; A 2/( A 2 p+A 2 c+A 2)  
         [0031]    where, ‘d2’ represents a gross area of the dummy line patterns  430 B, ‘d1’ represents a gross area of the dummy line patterns  430 A, ‘D’ represents an area of the dummy pad pool  440 . Also, ‘A2’ represents an area of the main fine line pattern  420 B, ‘A2p’ represents a gross area of the large pad pattern  400 B and ‘A2c’ represents a gross area of connection pad patterns  410 B. The dummy pad pool  440  and the dummy fine line patterns  430 A and  430 B do not make any electric circuit.  
         [0032]    Accordingly, the present invention can be applied in the damascene technology even if slurries for polishing metal wire patterns, such as Al or Cu wires, and cleaners, which are appropriate at a post cleaning process, are not developed.  
         [0033]    While the present invention has been described with respect to the particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.