Abstract:
A semiconductor device including a plurality of circuit regions formed in a semiconductor substrate and a scribe region formed around the circuit regions for separating the respective circuit regions, the scribe region having a plurality of laminated interlayer films including a plurality of metal films and an optically-transparent insulation film formed between and on the plurality of metal films, wherein a first metal film included in a first upper interlayer film of the plurality of interlayer films is positionally offset in a vertical direction to a second metal film included in a second lower interlayer film under the first interlayer film.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2008-306509 filed on Dec. 1, 2008, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The described embodiments relate to a semiconductor device and a method of manufacturing a semiconductor integrated circuit chip. 
       BACKGROUND 
       [0003]    Japanese Laid-open Patent Publication No. 2005-317866 describes that when a semiconductor device is manufactured, a semiconductor substrate is partitioned to chip regions and integrated circuits and the like are formed inside the chip regions. Then, chips are obtained by executing dicing along a scribe region located between the chip regions after the integrated circuits and the like are formed. Japanese Laid-open Patent Publication No. 2004-221286 describes that dicing is executed by radiating a laser beam to metal films formed in a scribe region. Note that the metal films in the scribe region are formed to uniformly execute polishing which is mainly chemical mechanical polishing (CMP). 
         [0004]    A configuration of a conventional scribe region will be explained.  FIGS. 1A and 1B  are views of a configuration of an example of the conventional scribe region. Note that  FIG. 1B  is a sectional view along a line I-I of  FIG. 1A . In the example, a scribe region  103  is located between a first chip region  101  and a second chip region  102 . In the scribe region  103 , an insulation film  122  is formed on a substrate  121 , and metal films  111 , which extend parallel to the scribe region  103 , are formed on the insulation film  122 . An insulation film  123 , which covers the metal films  111 , is formed on the insulation film  122 , and metal films  112 , which extend parallel to the scribe region  103 , are formed on the insulation film  123 . Further, an insulation film  124 , which covers the metal films  112 , is formed on the insulation film  123 . Note that the metal films  112  and the metal films  111  overlap with each other when viewed on a plane. This configuration has a purpose of making a design easy. 
         [0005]      FIGS. 2A and 2B  are views of a configuration of another example of the conventional scribe region. Note that  FIG. 2B  is a sectional view along a line I-I of  FIG. 2A . In the example, an insulation film  122  is formed on a substrate  121  in a scribe region  103 , and island-shaped metal films  113  are formed on the insulation film  122 . Further, an insulation film  123 , which covers the metal films  113 , is formed on the insulation film  122 , and island-shaped metal films  114  are formed on the insulation film  123 . Further, an insulation film  124 , which covers the metal films  114 , is formed on the insulation film  123 . Note that the metal films  114  and the metal films  113  overlap with each other when viewed on a plane. This configuration also has a purpose of making a design easy. 
       SUMMARY 
       [0006]    According to an aspect of the embodiment, a semiconductor device includes, a plurality of circuit regions formed in a semiconductor substrate; and a scribe region formed around the circuit regions for separating the respective circuit regions, the scribe region having a plurality of laminated interlayer films including a plurality of metal films and an optically-transparent insulation film formed between and on the plurality of metal films, wherein a first metal film included in a first upper interlayer film of the plurality of interlayer films is positionally offset in a vertical direction to a second metal film included in a second lower interlayer film under the first interlayer film. 
         [0007]    The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0008]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0009]      FIGS. 1A and 1B  are views of a configuration of an example of a conventional scribe region; 
           [0010]      FIGS. 2A and 2B  are views of a configuration of another example of the conventional scribe region; 
           [0011]      FIGS. 3A and 3B  are views of a semiconductor device according to a first embodiment; 
           [0012]      FIGS. 4A to 4C  are sectional views of a method of manufacturing a semiconductor integrated circuit chip in a sequence of steps; 
           [0013]      FIGS. 5A and 5B  are views of a semiconductor device according to a second embodiment; 
           [0014]      FIGS. 6A and 6B  are views of a semiconductor device according to a third embodiment; 
           [0015]      FIGS. 7A and 7B  are views of a semiconductor device according to a fourth embodiment; 
           [0016]      FIG. 8  is a sectional view of a semiconductor device according to a fifth embodiment; and 
           [0017]      FIG. 9  is a sectional view of a semiconductor device according to a sixth embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0018]    Embodiments will be explained below in detail referring to the accompanying drawings. 
       First Embodiment 
       [0019]    First, a first embodiment will be explained.  FIGS. 3A and 3B  are views of a semiconductor device according to the first embodiment. Note that  FIG. 3B  is a sectional view along a line I-I of  FIG. 3A . 
         [0020]    The semiconductor device according to the first embodiment is partitioned to chip regions by scribe regions extending longitudinally and laterally when viewed on a plane.  FIGS. 3A and 3B  illustrate a scribe region  21  and chip regions  22  and  23  having the scribe region  21  sandwiched therebetween. That is, the scribe region  21  is formed between the chip regions  22  and  23 . Two scan regions, which are to be scanned by a laser beam radiated thereto, are formed in the scribe region  21 . A spot, to which the laser beam is radiated, has a diameter of, for example, about 20 μm to 40 μm, and the scan regions also have a width of about 20 μm to 40 μm. Further, the scribe region  21  has a width of about 50 μm to 200 μm. 
         [0021]    In the scribe region  21 , an insulation film  2  is formed on a semiconductor substrate  1 , and strip-shaped metal films  11 , which extend parallel to the scribe region  21 , are formed on the insulation film  2 . Further, an optically-transparent insulation film  3 , which covers the metal films  11 , is formed on the insulation film  2 , and strip-shaped metal films  12 , which extend parallel to the scribe region  21 , are formed thereon. That is, the metal films  11  and  12  are disposed in a stripe state. Further, an optically-transparent insulation film  4  covering the metal films  12  is formed on the optically-transparent insulation film  3 . The optically-transparent insulation films  3  and  4  are composed of, for example, a silicon oxide film, a silicon oxide nitride film, or the like and cause a laser beam to transmit therethrough. The metal films  11  and  12  are composed of, for example, Cu (copper), Cu alloy, Al (aluminum), Al alloy, or the like and have a width of about 0.5 μm to 5 μm and a thickness of about 0.1 μm to 2 μm. Intervals between the metal films  11  and intervals between the metal films  12  are about 0.1 μm to 2 μm, respectively. The optically-transparent insulation film  3  has a thickness of about 0.1 μm to 2 μm on the metal films  11 . 
         [0022]    Further, the metal films  12  and the metal films  11  are disposed in the scribe region  21  at positions where they are offset from each other when viewed on a plane. That is, the positions of the metal films  11  in a direction parallel to a surface of the semiconductor substrate  1  are offset from the positions of the metal films  12  in the same direction so that a laser beam may reach both the metal films  11  and the metal films  12 , which are disposed below the metal films  11 , from thereabove. Therefore, since the laser beam may be radiated to the metal films  11  and  12  at the same time as described later, explosion may be caused in many regions in the scribe region  21  in a short time. 
         [0023]    Next, a method of manufacturing a semiconductor integrated circuit chip using the semiconductor device according to the first embodiment will be explained.  FIGS. 4A to 4C  are sectional views of the method of manufacturing the semiconductor integrated circuit chip in a sequence of steps. Note that  FIGS. 4A to 4C  illustrate laminated members such as the insulation film  2  disposed on the semiconductor substrate  1  in  FIG. 3  as a laminated portion  10 . 
         [0024]    First, a back surface of the semiconductor substrate  1  is bonded onto a table using an adhesive tape or the like. Next, as illustrated in  FIG. 4A , the laser beam is radiated to portions, which are located inside the scribe region  21  away from its edge by a predetermined distance, i.e., to the scan regions, and an irradiation position is moved in a direction where the scribe region  21  extends. That is, a scan is executed by radiating the laser beam. The diameter of the spot to which the laser beam is radiated is, for example, about 20 μm to 40 μm as described above. When the width of the scribe region  21  is 90 μm, first, a scan is executed to portions about 20 μm to 30 μm inside of the scribe region  21  from one edge thereof and thereafter a scan is executed to portions about 20 μm to 30 μm inside of the scribe region  21  from the other edge thereof. As a result, when energy is absorbed to the metal films  11  and  12  in the regions to which the laser beam is radiated and an amount of absorption of the energy reaches a predetermined value, the metal films  11  and  12  are exploded. 
         [0025]    When the metal films  11  and  12  are exploded, since the insulation film  2  in the periphery of the metal films  11  and  12  and the optically-transparent insulation films  3 ,  4  are also blown off, a groove  24  is formed in the laminated portion  10  in the scribe region  21  as illustrated in  FIG. 4B . 
         [0026]    Next, a rotating blade is inserted into the groove  24 , and the semiconductor substrate  1  is cut off from the groove as illustrated in  FIG. 4C . 
         [0027]    When a cut is executed by radiating the laser beam and using the blade, the chip regions partitioned by the scribe region are cut off to respective pieces and semiconductor integrated circuit chips may be obtained. Note that the method described above may be also applied to second to sixth embodiments to be described later. 
         [0028]    According to the first embodiment, since the metal films  11  and  12  of two layers may be exploded by radiating the laser beam once, a time necessary for dicing may be reduced. 
       Second Embodiment 
       [0029]    Next, a second embodiment will be explained.  FIGS. 5A and 5B  are views of a semiconductor device according to the second embodiment. Note that  FIG. 5B  is a sectional view along a line I-I of  FIG. 5A . 
         [0030]    The semiconductor device according to the second embodiment is partitioned to chip regions by scribe regions which extend longitudinally and laterally when viewed on a plane as in the first embodiment.  FIGS. 5A and 5B  illustrate a scribe region  21  and chip regions  22  and  23  having the scribe region  21  sandwiched therebetween. In the second embodiment, rectangular metal films  13  are formed in place of the metal films  11  in the first embodiment and rectangular metal films  14  are formed in an island state in place of the metal films  12  in the first embodiment, respectively. The metal films  13  and  14  are formed in the island state. The metal films  13  and  14  are composed of, for example, Cu, Cu alloy, Al, Al alloy, or the like and have a side length of about 0.5 μm to 5 μm and a thickness of about 0.1 μm to 2 μm. Intervals between the metal films  13  and intervals between the metal films  14  are about 0.1 μm to 2 μm, respectively. An optically-transparent insulation film  3  on the metal films  13  has a thickness of about 0.1 μm to 2 μm. The other configuration of the second embodiment is the same as that of the first embodiment. 
         [0031]    According to the second embodiment, the same advantage as that of the first embodiment may be obtained. Since the metal films  13  and  14  are formed in the island state and heat is less escaped, they may be more easily exploded than the metal films  11 ,  12  of the first embodiment. 
       Third Embodiment 
       [0032]    Next, a third embodiment will be explained.  FIGS. 6A and 6B  are views of a semiconductor device according to the third embodiment. Note that  FIG. 6B  is a sectional view along a line I-I of  FIG. 6A . 
         [0033]    The semiconductor device according to the third embodiment is also partitioned to chip regions by scribe regions which extend longitudinally and laterally when viewed on a plane as in the first embodiment.  FIGS. 6A and 6B  illustrate a scribe region  21  and a chip region  22 . Note that a chip region  23  is also formed as in the first embodiment. In the third embodiment, strip-shaped metal films  15 , which extend parallel to the scribe region  21 , are formed on an optically-transparent insulation film  4 . The metal films  15  are also disposed in a stripe state as in the metal films  11  and  12 . Further, an optically-transparent insulation film  5 , which covers the metal films  15 , is formed on the optically-transparent insulation film  4 . The optically-transparent insulation film  5  is also composed of, for example, a silicon oxide film, a silicon oxide nitride film, or the like as in the optically-transparent insulation films  3  and  4  and causes a laser beam to transmit therethrough. The metal films  15  are composed of, for example, Cu, Cu alloy, Al, Al alloy, or the like and have a side length of about 0.5 μm to 5 μm and a thickness of about 0.1 μm to 2 μm. Intervals between the metal films  11 , intervals between the metal films  12 , and intervals between the metal films  15  are about 0.1 μm to 2 μm, respectively. The optically-transparent insulation film  4  has a thickness of about 0.1 μm to 2 μm on the metal films  12 . Note that although  FIGS. 6A and 6B  illustrate a portion of the scribe region  21  on the chip region  22  side, the metal films  11 ,  12 ,  15  are also disposed on the chip region  23  side. The other configuration of the third embodiment is the same as that of the first embodiment. 
         [0034]    According to the third embodiment, since the metal films  11 ,  12 , and  15  of three layers may be exploded by radiating the laser beam once, a time necessary to dicing may be more reduced than that of the first embodiment. 
         [0035]    Note that the metal films  13  and  14  may be used in place of the metal films  11  and  12 , the metal films  15  may have a rectangular shape similar to those of the metal films  13  and  14 , and the metal films  15  may be disposed in an island state. 
       Fourth Embodiment 
       [0036]    Next, a fourth embodiment will be explained.  FIGS. 7A and 7B  are views of a semiconductor device according to the fourth embodiment. Note that  FIG. 7B  is a sectional view along a line I-I of  FIG. 7A . 
         [0037]    The semiconductor device according to the fourth embodiment is also partitioned to chip regions by scribe regions which extend longitudinally and laterally when viewed on a plane as in the first embodiment.  FIGS. 7A and 7B  illustrate a scribe region  21  and chip regions  22  and  23  having the scribe region  21  sandwiched therebetween. In the fourth embodiment, since metal films  11  and  12  have a width larger than that of the first embodiment, they have portions overlapping with each other when viewed on a plane. Then, conductive plugs  31  for connecting the overlapping portions are formed. The plugs  31  are composed of metal of, for example, W (tungsten), Al, Cu, and the like. The other configuration of the fourth embodiment is the same as that of first embodiment. 
         [0038]    According to the fourth embodiment, the same advantage as that of the first embodiment may be obtained. Further, even if a laser beam radiated to the metal films  11  is partly reflected, since the reflected laser beam is absorbed by the plug  31 , a laser beam absorption efficiency may be more improved than that of the first embodiment. 
         [0039]    Note that rectangular metal films  13  and  14  may be used in place of the metal films  11  and  12 . 
       Fifth Embodiment 
       [0040]    Next, a fifth embodiment will be explained.  FIG. 8  is a sectional view of a semiconductor device according to the fifth embodiment.  FIG. 8  illustrates a cross section orthogonal to a direction in which a scribe region  21  extends as in  FIG. 3B  and the like. Further, although  FIG. 8  illustrates the scribe region  21  and a chip region  22  as in  FIG. 6 , a chip region  23  is also formed as in the first embodiment. 
         [0041]    In the fifth embodiment, metal films  41  to  48  are dispose so that they are offset from each other when viewed on a plane in a region having a width (for example, about 25 μm) equal to or less than a diameter (for example, about 30 μm) of a radiation spot of a laser beam as illustrated in  FIG. 8 . The metal films  41  to  48  have a stripe shape similar to that of, for example, the metal films  11 ,  12 , and  15  and extend parallel to the scribe region  21 . Note that although  FIG. 8  illustrates a portion on the chip region  22  side of the scribe region  21 , the metal films  41  to  48  are also disposed on the chip region  23  side. Further, two pieces each of the metal films  42  to  48  are disposed in one piece of the metal film  41  on each of the chip region  22 ,  23  sides, and the metal films  42  to  48  are disposed in this order when viewed on a plane so that they are away from the metal film  41 . That is, the metal films  41  to  48  are disposed in a “V shape” on a cross section orthogonal to a direction in which the scribe region  21  extends. 
         [0042]    Further, in the scribe region  21 , an insulation film  52  is formed on a semiconductor substrate  51 , and the metal film  41  is formed on the insulation film  52 . Further, an optically-transparent insulation film  53 , which covers the metal films  41 , is formed on the insulation film  52 , and the metal films  42  are formed on the optically-transparent insulation film  53 . Further, an optically-transparent insulation film  54 , which covers the metal films  42 , is formed on the optically-transparent insulation film  53 . The metal films  43  are formed on the optically-transparent insulation film  54 , and further an optically-transparent insulation film  55 , which covers the metal films  43 , is also formed on the optically-transparent insulation film  54 . The metal films  44  are formed on the optically-transparent insulation film  55 , and an optically-transparent insulation film  56 , which covers the metal films  44 , is also formed on the optically-transparent insulation film  55 . The metal films  45  are formed on the optically-transparent insulation film  56 , and further an optically-transparent insulation film  57 , which covers the metal films  45 , is also formed on the optically-transparent insulation film  56 . The metal films  46  are formed on the optically-transparent insulation film  57 , and further an optically-transparent insulation film  58 , which covers the metal films  46 , is also formed on the optically-transparent insulation film  57 . The metal films  47  are formed on the optically-transparent insulation film  58 , and further an optically-transparent insulation film  59 , which covers the metal films  47 , is also formed on the optically-transparent insulation film  58 . Further, the metal films  48  are formed on the optically-transparent insulation film  59 , and further an optically-transparent insulation film  60 , which covers the metal film  48 , is also formed on the optically-transparent insulation film  59 . 
         [0043]    The metal films  41  to  43  are composed of, for example, Cu and have a width of about 0.7 μm and a thickness of about 0.3 μm. The optically-transparent insulation films  53  and  55  are composed of, for example, a silicon oxide nitride film and cause a laser beam to transmit therethrough. The optically-transparent insulation films  53  to  55  have a thickness of about 0.3 μm on the metal films  41  to  43 . The metal films  44  and  45  are composed of, for example, Cu and have a width of about 0.7 μm and a thickness of about 0.5 μm. The optically-transparent insulation films  56  and  57  are composed of, for example, a silicon oxide nitride film and cause a laser beam to transmit therethrough. The optically-transparent insulation films  56  and  57  have a thickness of about 0.5 μm on the metal films  44  and  45 . The metal films  46  and  47  are composed of, for example, Cu and have a width of about 1 μm and a thickness of about 1 μm. The optically-transparent insulation films  58  and  59  are composed of, for example, a silicon oxide film and causes a laser beam to transmit therethrough. The optically-transparent insulation films  58  and  59  have a thickness of about 0.6 μm on the metal films  46  and  47 . The metal film  48  is composed of, for example, Al and have a width of about 2 μm and a thickness of about 1 μm. The optically-transparent insulation film  60  is composed of, for example, a silicon oxide film and causes a laser beam to transmit therethrough. The optically-transparent insulation film  60  has a thickness of about 0.8 μm on the metal films  48 . 
         [0044]    According to the fifth embodiment, since the metal films  41  to  48  of eight layers may be exploded by radiating a laser beam once, a time necessary for dicing may be more reduced. Further, since an increase in the number of the metal films makes a laser beam more unlikely to leak to the chip regions  22  and  23 , damage and the like to chips, such as cracks, due to the leakage of the laser beam may be suppressed. 
         [0045]    Note that the metal films  41  to  47  may have a rectangular shape similar to that of the metal films  13  and  14  and may be disposed in an island state. 
       Sixth Embodiment 
       [0046]    Next, a sixth embodiment will be explained.  FIG. 9  is a sectional view of a semiconductor device according to the sixth embodiment.  FIG. 9  illustrates a cross section orthogonal to a direction in which a scribe region  21  extends as in  FIG. 1B  and the like. Further, although  FIG. 9  illustrates the scribe region  21  and a chip region  22  as in  FIG. 6 , a chip region  23  is also formed as in the first embodiment. 
         [0047]    In the sixth embodiment, since metal films  41  to  48  have a width larger than that of the fifth embodiment as in the fourth embodiment, they have portions overlapping with each other when viewed on a plane. Then, conductive plugs  61  for connecting the overlapping portions are formed. The plugs  61  are composed of metal of, for example, W (tungsten), Al, Cu, and the like. The other configuration of the sixth embodiment is the same as that of fifth embodiment. 
         [0048]    According to the sixth embodiment, the same advantage as that of the fifth embodiment may be obtained. Further, even if a laser beam radiated to the metal films  41  to  48  is partly reflected, since the reflected laser beam is absorbed by the plugs  61 , a laser beam absorption efficiency may be improved over that of the fifth embodiment. 
         [0049]    Note that although the metal films are disposed by being offset between the layers in the direction orthogonal to the direction in which the scribe region  21  extends in the first to sixth embodiments, the direction in which the metal films are offset is not particularly limited to the above direction. For example, the metal films may be offset in parallel to the direction in which the scribe region  21  extends. That is, it is sufficient that a laser beam is radiated to the metal films of the layers by being radiated once. 
         [0050]    Further, it is not necessary that the optically-transparent films be the insulation films in the scribe region  21 . 
         [0051]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to the superiority and inferiority of the invention. Although the embodiment(s) of the present inventions have been described in detail, it should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.