Abstract:
Provided is a semiconductor integrated circuit. The semiconductor integrated circuit comprises: a pair of interconnections; a fuse connecting the pair of interconnections; and one or more heat dissipation patterns connecting the pair of interconnections and are disposed around the fuse.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority under 35 U.S.C. §119(a) to Korean Patent Application No. 10-2010-0008693, filed on Jan. 29, 2010, in the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety as if set forth in full. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    Various embodiments of the present disclosure generally relate to a semiconductor integrated circuit (IC), and more particularly, to an electrical fuse structure of a semiconductor IC. 
         [0004]    2. Related Art 
         [0005]    Semiconductor ICs comprise a fuse to repair an error cell, store a chip identification (ID), and provide a variety of mode signals. 
         [0006]    Such a fuse may be a laser blowing type or an electrical blowing type. 
         [0007]    A fuse blown by laser beams may have an effect upon an adjacent fuse line when the laser beams are irradiated. Therefore, the fuse needs to be spaced a predetermined distance or more from the fuse line. This may degrade layout efficiency in a high-integrated semiconductor circuit. 
         [0008]    When a programming current is applied to a fuse link in the electrical blowing type fuse, the fuse link blows due to an electromigration (EM) effect and Joule heating. Such an electrical blowing type fuse may be utilized even after a package level, and is referred to as an electrical fuse. 
         [0009]      FIG. 1  is a schematic perspective view showing a state in which a conventional electrical fuse is ruptured. Referring to  FIG. 1 , an electrical fuse F connects upper and lower conductive layers M 1  and M 2 , and is ruptured by a programming current flowing between the upper and lower conductive layers M 1  and M 2 . 
         [0010]    When the electrical fuse F is ruptured, the temperature of the ruptured portion of the electrical fuse F may rise up to several thousand degrees. When such high temperature is reached, a large amount of high-temperature heat  10  radiates externally. 
         [0011]    The radiating high-temperature heat is transferred to adjacent elements to change the properties of semiconductor devices formed at positions adjacent to the fuse. 
       SUMMARY OF THE INVENTION 
       [0012]    In one aspect of the present invention, a semiconductor integrated circuit comprises: a pair of interconnections; a fuse connecting the pair of interconnections; and one or more heat dissipation patterns connecting the pair of interconnections and are disposed around the fuse. 
         [0013]    In another aspect of the present invention, a semiconductor integrated circuit comprises: a first lower interconnection having a predetermined area; a second lower interconnection positioned on substantially the same plane as the first lower interconnection and spaced a predetermined distance from the first lower interconnection; a first upper interconnection configured to overlap with the first lower interconnection; a second upper interconnection positioned on substantially the same plane as the first upper interconnection, spaced a predetermined distance from the first upper interconnection, and configured to overlap with the second lower interconnection; a fuse connected to the first lower interconnection and the second upper interconnection; a first group of heat dissipation paths connecting the first lower interconnection and the first upper interconnection and disposed around the fuse; and a second group of heat dissipation paths connecting the second lower interconnection and the second upper interconnection and are disposed around the fuse. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. 
           [0015]      FIG. 1  is a schematic perspective view showing a state in which a conventional electrical fuse is ruptured; 
           [0016]      FIG. 2  is an equivalent circuit diagram of an electrical fuse structure, according to one embodiment of the invention; 
           [0017]      FIG. 3  is a plan view of the electrical fuse structure, according to one embodiment of the invention; 
           [0018]      FIG. 4  is a perspective view of the electrical fuse structure taken along the line IV-IV′ of  FIG. 3 ; and 
           [0019]      FIG. 5  is a plan view of an electrical fuse structure according to one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Advantages and characteristics of the present invention and a method for achieving them will be apparent with reference to embodiments described below in addition with reference to the accompanying drawings. However, the present invention is not limited to the exemplary embodiments described below but may be implemented in various forms. Therefore, the exemplary embodiments are provided to enable those skilled in the art to thoroughly understand the teaching of the present invention and to completely inform the scope of the present invention and the exemplary embodiment is just defined by the scope of the appended claims. Throughout the specification, like elements refer to like reference numerals. 
         [0021]      FIG. 2  is a fuse structure  100 , according to one embodiment of the invention. The fuse structure  100  according to the embodiment comprises an electrical fuse  120  that connects a program voltage source Vp and a drive transistor T. 
         [0022]    A plurality of heat dissipation paths  130  surrounds the electrical fuse  120 . Each of the heat dissipation paths  130  may also connect the program voltage source Vp and the drive transistor T. 
         [0023]    The drive transistor T connects the electrical fuse  120  and a ground terminal VSS, and is driven by a repair signal S. 
         [0024]    When the repair signal S is activated, the drive transistor T is turned on and applies a large amount of current to the electrical fuse  120 . The electrical fuse  120  is then ruptured by the heat caused by the current. 
         [0025]    Afterwards, the plurality of heat dissipation paths  130  surrounding the electrical fuse  120  relieve the heat generated from the rupturing of the electrical fuse  120 , and then externally discharge the residual heat with a lowered temperature. 
         [0026]      FIG. 3  is a detailed diagram of the electrical fuse structure  100 . 
         [0027]    Referring to  FIG. 3 , the electrical fuse  120  may be electrically connected to a lower interconnection  110 , which is connected to the drive transistor T, and an upper interconnection  140 , which is connected to the program voltage source VP. Also,  FIG. 4  shows a perspective view of the electrical fuse structure taken along the line IV-IV′ of  FIG. 3 . 
         [0028]    According to the embodiment, with reference to  FIGS. 3 and 4 , the lower interconnection  110  may be divided into a first lower interconnection  110   a  and a second lower interconnection  110   b,  which are positioned on substantially the same plane. The first and second lower interconnections  110   a  and  110   b  are spaced a predetermined distance from each other. Furthermore, the first and second lower interconnections  110   a  and  110   b  have substantially rectangular shapes. The first lower interconnection  110   a  may comprise a protruding portion, and the second lower interconnection  110   b  may comprise a concave portion that accomodates the protruding portion. 
         [0029]    The upper interconnection  140  faces the lower interconnection  110 , separated by a predetermined distance. An insulating layer may be interposed between the upper and lower interconnections  140  and  110 . The upper interconnection  140  may be divided into a first upper interconnection  140   a  and a second upper interconnection  140   b,  which are positioned on substantially the same plane. The first and second upper interconnections  140   a  and  140   b  may overlap the first and second lower interconnections  110   a  and  110   b,  respectively. In particular, the second upper interconnection  140   b  overlaps the protruding portion of the first lower interconnection  110   a.  Furthermore, the first and second upper interconnections  140   a  and  140   b  are also spaced by a predetermined distance. 
         [0030]    The space between the upper and lower interconnections may serve as a heat release path, and may selectively increase the current density of the lower interconnection. This will be described below in detail. 
         [0031]    The electrical fuse  120  is electrically connected to the protruding portion of the first lower interconnection  110   a  and the second upper interconnection  140   b.  The electrical fuse  120  may be formed in a contact plug shape, for example. 
         [0032]    Meanwhile, a plurality of heat dissipation paths  130  are provided around the electrical fuse  120  between the lower and upper interconnections  110  and  140 . 
         [0033]    The plurality of heat dissipation paths  130  may be divided into a first group of heat dissipation paths  130 _ 1  that connects the first lower interconnection  110   a  and the first upper interconnection  140   a  and a second group of heat dissipation paths  130 _ 2  that connects the second upper interconnection  110   b  and the second upper interconnection  140   b.    
         [0034]    The first group of heat dissipation paths  130 _ 1  comprise a plurality of heat dissipation patterns which electrically connect the first upper and lower interconnections  110   a  and  140   a.  The plurality of heat dissipation patterns composing the first heat dissipation group  130 _ 1  may be divided into main heat dissipation patterns  130   a  and sub heat dissipation patterns  130   b.  The main heat dissipation patterns  130   a  lengthen a moving distance of heat to reduce the overall amount of heat dissipation, and the sub heat dissipation patterns  130   b  are positioned around the main heat dissipation patterns  130   a.    
         [0035]    The main heat dissipation patterns  130   a  are bent at least once to lengthen heat transfer paths in a limited area. Furthermore, one end of each of the main heat dissipation patterns  130   a  is disposed adjacent to the fuse  120 . The other end faces the edges of the first upper and lower interconnections  110   a  and  140   a  and is spaced from the fuse  120 . Accordingly, the high-temperature heat generated when the electrical fuse  120  is ruptured is transferred through as long a path as possible, and then discharged externally with a lowered temperature. One or more main heat dissipation patterns  130   a  may be provided. According to the embodiment, the first main group of heat dissipation paths  130 _ 1  may comprise one pair of symmetrical main heat dissipation patterns  13 . However, the structure of the main heat dissipation patterns  130   a  is not limited to this embodiment, and the main heat dissipation patterns  130   a  may be bent in various forms. 
         [0036]    The plurality of sub heat dissipation patterns  130   b  may be arranged in a stripe shape, for example, around the main heat dissipation patterns  130   a.  The sub heat dissipation patterns  130   b  may relieve the heat dissipated by the main heat dissipation patterns  130   a  once more, and then discharge the heat externally. The sub heat dissipation patterns  130   b  are not limited to the stripe shape and may be formed in various other shapes. The sub heat dissipation patterns  130   b  may induce a temperature reduction caused by the collision of high-temperature heat or by stretching the heat transfer paths. 
         [0037]    The second group of heat dissipation paths  130 _ 2  also may comprise a plurality of heat dissipation patterns which are electrically connected to the second lower interconnection  110   b  and the second upper interconnection  140   b.  The plurality of heat dissipation patterns composing the second group of heat dissipation paths  130 _ 2  may be divided into main heat dissipation patterns  130   a  and sub heat dissipation patterns  130   b  and  130   c.  The main heat dissipation patterns  130   a  increase a moving distance of heat generated from the fuse  120  to reduce the overall amount of heat dissipation, and the sub heat dissipation patterns  130   b  and  130   c  are positioned around the main heat dissipation patterns  130   a.    
         [0038]    The main heat dissipation patterns  130   a  of the second group of heat dissipation paths  130 _ 2  may play the same role as the man heat dissipation patterns  130   a  formed in the first group of heat dissipation paths  130 _ 1 , and may be symmetric. 
         [0039]    The sub heat dissipation patterns  130   b  and  130   c  of the second group of heat dissipation paths  130 _ 2  are configured to discharge heat dissipated by the main heat dissipation patterns  130   a  externally, like the sub heat dissipation patterns  130   b  of the first group of heat dissipation paths  130 _ 1 . The sub heat dissipation patterns  130   c  in the concave portion of the second lower interconnection  110   b  are shorter than the sub heat dissipation patterns  130   b  due to the structure of the second lower interconnection  110   b.    
         [0040]    The lower interconnections  110   a  and  110   b  may be configured to have a higher resistance than the upper interconnections  140   a  and  140   b  because the currents are concentrated on the fuse  120 . Due to this structure, it is possible to secure a low current density. In this embodiment, a larger number of heat dissipation patterns are positioned at the second lower interconnection  110   b  than at the first lower interconnection  110   a.  This configuration substantially increases the resistance of the first lower interconnection  110   a,  which is directly connected to the fuse  120 . 
         [0041]    When a predetermined amount of current is applied to the fuse  120  in the semiconductor apparatus configured in the above-described manner, high-temperature heat is generated in the center of the fuse  120  to rupture the fuse  120 . 
         [0042]    The high-temperature heat generated when the fuse  120  is ruptured collides with the plurality of heat dissipation patterns  130   a  to  130   c  disposed around the fuse  120 , and the temperature thereof is primarily lowered. Then, while the heat flows along the paths of the heat dissipation patterns  130   a  to  130   c,  the temperature is secondarily lowered. Therefore, when the heat is discharged externally, the temperature becomes low enough such that it has no external effect. Accordingly, it is possible to reduce a thermal burden of adjacent cells caused by the fuse rupture. 
         [0043]    Referring to  FIG. 5 , the first and second group of heat dissipation paths  130 _ 1  and  130 _ 2  may further comprise loop-shaped heat dissipation patterns  135 . The loop-shaped heat dissipation patterns  135  are disposed at the edges of the first and second upper and lower interconnections  110   a,    140   a,    110   b,  and  140   b.  It also loops the residual heats which are relived by the main heat dissipation patterns  130   a  and/or the sub heat dissipation patterns  130   b  and  130   c.  The heat is then discharged with a lowered temperature. 
         [0044]    At this time, some of the main heat dissipation patterns  130   a  and the sub heat dissipation patterns  130   b  and  130   c  in the first and second group of heat dissipation paths  130 _ 1  and  130 _ 2  may be removed depending on the sizes of the first and second upper and lower interconnections  110   a,    140   a,    110   b,  and  140   b,  and the line width of the loop-shaped heat dissipation patterns  135 . 
         [0045]    The addition of the loop-shaped heat dissipation pattern  135  may further lower the temperature of the heat generated by a ruptured fuse, possibly preventing property change of adjacent elements. 
         [0046]    According to the embodiment of the present invention, various types of heat dissipation patterns are formed in a contact structure similar to the fuse. The temperature of the heat generated when the fuse is ruptured is accordingly lowered by the collision with the heat dissipation patterns and the paths thereof. When the heats are discharged externally, the temperature is too low to affect the outside. Therefore, the thermal burden of the adjacent cells is reduced. 
         [0047]    Furthermore, the density of the heat dissipation patterns may be adjusted to improve a current density at the lower interconnection. Therefore, it is possible to improve the fuse rupture efficiency. 
         [0048]    While certain embodiments have been described above, it will be understood to those skilled in the art that the embodiments described are by way of example only. Accordingly, the device and method described herein should not be limited based on the described embodiments. Rather, the apparatus described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings.