Patent Document

CROSS-REFERENCE TO RELATED PATENT APPLICATION  
       [0001]     This patent application claims priority from Korean Patent Application No. 10-2005-0006848, filed Jan. 25, 2005, the contents of which are hereby incorporated by reference in their entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to structures formed on a semiconductor substrate and to methods of forming the same, and more particularly, to scribe-line structures formed on a semiconductor substrate, to substrates having such scribe-line structures, and to methods of forming the same.  
         [0004]     2. Description of the Related Art  
         [0005]     Generally, multiple semiconductor devices are formed respectively on predetermined regions of a semiconductor substrate. Each of these regions may be defined by a set of intersecting scribe-lines, for example by horizontal and vertical scribe-lines. Each such scribe-line has a predetermined width, so that the semiconductor substrate can be easily cut along the scribe-lines so as to separate the individual semiconductor devices from each other and from any unused portions of the semiconductor substrate. Before performing the cutting process described above, the semiconductor devices and the scribe-lines are typically covered with a plurality of interlayer insulating layers. The interlayer insulating layers protect the semiconductor devices from exterior environment influences while cutting the semiconductor substrate.  
         [0006]     But, in recent manufacturing operations in this field, it has been found that it is often necessary to replace each of the interlayer insulating layers used to protect the formed semiconductor devices with other materials having lower dielectric constants to avoid interfering with the higher-speed operation of modern semiconductor devices. A common characteristic of such materials having a lower dielectric constant, however, is that the mechanical intensity of these materials is often lower than that of silicon oxide (SiO 2 ). As a result, such materials having a lower dielectric constant are readily subject to physical shock and have a tendency to crack along or adjacent to the semiconductor devices during the step of performing the cutting process along the scribe-lines.  
         [0007]     In one approach to these familiar problems, U.S. Pat. No. 6,441,465 to Chi-Fa Lin (the &#39;465 patent), which is incorporated herein by reference, discloses a scribe line structure for preventing the type of damages as described above that may be induced during fabrication processes. According to the &#39;465 patent, the scribe-line structure intentionally includes cavities disposed in a multi-layer structure along a scribe-line. The cavities are disposed on each side of a scribe-line and then disposed in at least two rows. The &#39;465 patent teaches that such cavities reduce and relieve internal stress of the scribe lines, which may be created during formation of the scribe-line and thus reduce the tendency for crack formation, peeling, delamination and dielectric fracture of the scribe lines during cutting of the substrate.  
         [0008]     However, the scribe-line structure taught by the &#39;465 patent also can cause damage to the semiconductor devices because the cavities act as starting points for a crack during performing a cutting process along a scribe-line. Besides, the cavities also act as obstructions while performing the cutting process along the scribe-line, so that the processing time may be made longer than would otherwise be required.  
         [0009]     These and other problems with or limitations of the prior art techniques in this field are addressed in whole, or at least in part, by the structures and methods of this invention.  
       SUMMARY OF THE INVENTION  
       [0010]     According to one embodiment of the present invention, there are provided scribe-line structures on a semiconductor substrate such that during performance of a cutting process on the semiconductor substrate, physical shock and cracking tendencies on the one or more semiconductor devices formed on the substrate can be minimized.  
         [0011]     According to another embodiment of the present invention, there are provided methods of forming scribe-line structures such that during performance of a cutting process on a semiconductor substrate having such scribe-line structures thereon, physical shock and cracking tendencies on the semiconductor devices formed on the substrate can be minimized.  
         [0012]     To accomplish the objects described above and other related objectives, the present invention provides new types of scribe-line structures and methods of forming such scribe-line structures.  
         [0013]     One embodiment of scribe-line structures according to this invention comprises a lower layer disposed on a semiconductor substrate. A molding layer having at least one protective contact hole is then disposed on the lower layer. A dielectric layer and an upper layer are thereafter disposed in sequence on the molding layer so as to fill the protective contact hole(s). On the upper layer, protective layer patterns are then disposed so as to be spaced a distance away from each other. The spacing distance between the protective layer patterns should be different in size from a width of the protective contact hole(s). Also, the dielectric layer should be formed of a material having a greater mechanical intensity (or strength) than that of the molding layer.  
         [0014]     Another embodiment of scribe-line structures according to this invention comprises a lower layer disposed on a semiconductor substrate. A pad layer and a molding layer having at least one protective contact hole are then disposed on the lower layer in sequence. A dielectric layer and an upper layer are thereafter disposed in sequence on the molding layer so as to fill the protective contact hole(s). On the upper layer, protective layer patterns are then disposed so as to be spaced a distance away from each other. The spacing distance between the protective layer patterns should be different in size from a width of the protective contact hole(s). Also, the dielectric layer and the pad layer should be formed of a material or of materials having a greater mechanical intensity (or strength) than that of the molding layer.  
         [0015]     Still another embodiment of scribe-line structures according to this invention comprises a lower layer and a pad layer disposed in order on a semiconductor substrate. A molding layer having at least one protective contact hole is then disposed on the pad layer. A dielectric layer and an upper layer are thereafter disposed in sequence on the molding layer so as to fill the protective contact hole(s). On the upper layer, protective layer patterns are then disposed so as to be spaced a distance away from each other. The spacing distance between the protective layer patterns should be different in size from a width of the protective contact hole(s). Also, the dielectric layer and the pad layer should be formed of a material or of materials having a greater mechanical intensity (or strength) than that of the molding layer.  
         [0016]     One embodiment of a method of forming scribe-line structures according to this invention comprises the initial steps of forming a lower layer and a molding layer on a semiconductor substrate in sequence. A photoresist layer is then formed on the molding layer. The photoresist layer is formed so as to have at least one opening extending down to the molding layer. The molding layer is then etched through the opening(s) using the photoresist layer as an etching mask. The etching process forms one or more protective hole(s) in the molding layer to expose the lower layer. The photoresist layer is thereafter removed from the semiconductor substrate. On the molding layer, a dielectric layer, an upper layer, and a set of protective layer patterns are then formed in sequence so as to fill the protective hole(s). The dielectric layer should be formed using a material having a greater mechanical intensity (strength) than that of the molding layer.  
         [0017]     Another embodiment of a method of forming scribe-line structures according to this invention comprises the initial steps of forming a lower layer, a pad layer, and a molding layer on a semiconductor substrate in sequence. A photoresist layer is then formed on the molding layer. The photoresist layer is formed so as to have at least one opening extending down to the molding layer. The molding layer and the pad layer are then etched in sequence through the opening(s) using the photoresist layer as an etching mask. The etching process forms one or more protective hole(s) in the pad layer and the molding layer to expose the lower layer. The photoresist layer is thereafter removed from the semiconductor substrate. On the molding layer, a dielectric layer, an upper layer, and a set of protective layer patterns are then formed in sequence so as to fill the protective hole(s). The dielectric layer and the pad layer should be formed using a material or materials having a greater mechanical intensity (strength) than that of the molding layer.  
         [0018]     Still another embodiment of a method of forming scribe-line structures according to this invention comprises the initial steps of forming a lower layer, a pad layer, and a molding layer on a semiconductor substrate in order. A photoresist layer is then formed on the molding layer. The photoresist layer is formed so as to have at least one opening extending down to the molding layer. The molding layer is then etched through the opening(s) using the photoresist layer as an etching mask. The etching process forms one or more protective hole(s) in the molding layer and the pad layer to expose the lower layer. The photoresist layer is thereafter removed from the semiconductor substrate. On the molding layer, a dielectric layer, an upper layer, and a set of protective layer patterns are then formed in sequence so as to fill the protective hole(s). The dielectric layer and the pad layer should be formed using a material or materials having a greater mechanical intensity (strength) than that of the molding layer. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     Exemplary embodiments of the invention will be readily apparent to those of ordinary skill in the art upon review of the detailed description that follows when taken in conjunction with the accompanying drawings, in which like reference numerals denote like parts or elements. In the drawings:  
         [0020]      FIG. 1  is a schematic layout diagram illustrating scribe-line structures formed along a face of a semiconductor substrate having at least a semiconductor device thereon, the scribe-line structures being formed according to the present invention;  
         [0021]      FIGS. 2 and 3  are two schematic cross-sectional views, each of a different scribe-line structure as seen in  FIG. 1 , taken along the section line I-I′ of  FIG. 1 , respectively; and  
         [0022]     FIGS.  4  to  11  are schematic cross-sectional views, taken along the section line I-I′ of  FIG. 1 , illustrating the sequential steps in two methods of forming scribe-line structures according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]      FIG. 1  is a schematic layout diagram illustrating scribe-line structures formed along a semiconductor substrate having at least a semiconductor device thereon, the scribe-line structures being formed according to the present invention, and  FIGS. 2 and 3  are schematic cross-sectional views of two different scribe-line structures as seen in  FIG. 1  taken along the section line I-I′ of  FIG. 1 , respectively.  
         [0024]     Referring to FIGS.  1  to  3 , a lower layer  20  and a pad layer  30  are sequentially disposed on a semiconductor substrate  10 . A molding layer  40  is disposed on the pad layer  30 . The molding layer  40  has a first protective contact hole  47  (as seen in  FIG. 2 ) or alternatively has first and second protective contact holes  48  (as seen in  FIG. 3 ), or, as shown in  FIG. 1 , both. The first protective contact hole  47  and/or the first and second protective contact holes  48  may be surrounded with the molding layer  40  along the sides and the pad layer  30  along the bottom(s) thereof. In some invention embodiments, however, the pad layer  30  may not be disposed between the molding layer  40  and the lower layer  20 . In this case, the first protective contact hole  47  and/or the first and second protective contact holes  48  may be surrounded with the molding layer  40  along the sides and the lower layer  20  along the bottom(s) thereof. It is desirable that the lower layer  20  consist essentially of a material having a greater mechanical intensity (strength) than that of either the pad layer  30  or the molding layer  40 . The lower layer  20  may, for example, be formed of silicon oxide (SiO 2 ).  
         [0025]     At the same time, the molding layer  40  should preferably consist essentially of a material having a lower mechanical intensity (strength) than that of the pad layer  30 . It is especially desirable that the pad layer  30  be formed of what will herein be called a “low-k material,” for example a material selected from the group consisting of the substances commonly known in the trade as Black Diamond, Coral, Aurora, and materials having dielectric constants similar thereto. For some invention embodiments, the pad layer  30  and the molding layer  40  may alternatively be formed of what will herein be called a “lower-k material,” for example a material selected from the group consisting of the substances commonly known in the trade as Nanoporous silicate, BCB, Flare, ALCAP, LKD, and materials having dielectric constants similar thereto. For some invention embodiments, the molding layer  40  may be composed of a compositie of two or more low-k materials. For some invention embodiments, the pad layer  30  may also be composed of a compositie of two or more of the previously mentioned low-k materials or of two or more of the previously mentioned lower-k materials. It is also desirable in accordance with this invention that a set of the protective hole(s), such as first protective contact hole  47 , be disposed along a scribe-line  90  of  FIG. 1  to form a trench as shown in  FIG. 2 . The trench has a predetermined contact hole width B. It is similarly desirable that a set of the first and second protective contact holes  48  be disposed along the scribe-line  90  of  FIG. 1  to form two trenches as shown in  FIG. 3 . Each of the first and second protective contact holes  48  in  FIG. 3  defines a trench with a predetermined contact hole width C.  
         [0026]     A base layer  50 , a buried layer  60 , and an upper layer  70  may be sequentially disposed on the molding layer  40  so as to fill the first protective contact hole  47  ( FIG. 2 ) and/or the first and second protective contact holes  48  ( FIG. 3 ). It is particularly desirable that the upper layer  70  be formed of silicon nitride (Si 3 N 4 ). It is also desirable that the buried layer  60  and the base layer  50  be formed of a material or materials having a lower mechanical intensity (strength) than that of the lower layer  20 . It is particularly desirable, for example, that the base layer  50  and the buried layer  60  consist essentially of a low-k material selected from the group consisting of Black Diamond, Coral, Aurora, or materials having dielectric constants similar thereto. In another invention embodiment, the base layer  50  may be a low-k material selected from the group consisting of Black Diamond, Coral, Aurora, or materials having dielectric constants similar thereto, while the buried layer  60  may be a lower-k material selected from the group consisting of Nanoporous silicate, BCB, Flare, ALCAP, LKD, or materials having dielectric constants similar thereto. Also, the base layer  50  may be lower-k material comprising Nanoporous silicate, BCB, Flare, ALCAP, LKD, or materials having dielectric constants similar thereto, while the buried layer  60  may be a low-k material selected from the group consisting of Black Diamond, Coral, Aurora, or materials having dielectric constants similar thereto. Hereinafter, the combination of base layer  50  and buried layer  60 , or, if only one is present, the one layer, will be referred to as dielectric layer  65 . Thus, the dielectric layer  65  may comprise either the buried layer  60  or the base layer  50 . The dielectric layer  65  may also be composed of two or more low-k materials. Alternatively, the dielectric layer  65  may be composed of a combination of two or more low-k materials and also of two or more lower-k materials, said material layers being stacked in turn.  
         [0027]     Protective layer patterns  80  are shown disposed on the upper layer  70 . It is desirable that the protective layer patterns  80  be disposed so as to be spaced a distance away from each other. As seen in  FIG. 2  and  FIG. 3  respectively, a spacing distance A between the protective layer patterns  80  is different from either the contact hole width B of the first protective contact hole  47  ( FIG. 2 ) or the contact hole width C of each of the first and second protective contact holes  48  ( FIG. 3 ). It is particularly desirable that the protective layer patterns  80  be formed of polyimide.  
         [0028]     FIGS.  4  to  11  are schematic cross-sectional views, taken along the section line I-I′ of  FIG. 1 , illustrating sequential steps in two methods according to the present invention of forming scribe-line structures on a semiconductor substrate.  
         [0029]     Referring to  FIGS. 1, 4 , and  5 , a lower layer  20  and a pad layer  30  are sequentially formed on a semiconductor substrate  10 . A molding layer  40  and a photoresist layer  42  are then formed so as to be sequentially stacked on the pad layer  30 . The photoresist layer  42  is formed to have at least one opening, for example the single opening  44  in  FIG. 4  and/or the two openings  44  seen in  FIG. 5 . An etching process  46  is then performed on the molding layer  40  through the one or more openings  44  using the photoresist layer  42  as an etching mask. The etching process (represented by the arrows  46 ) forms a first protective contact hole  47  as shown in  FIG. 4  or, alternatively, first and second protective contact holes  48  as shown in  FIG. 5 , in the molding layer  40 . The first protective contact hole  47  or the first and second protective contact holes  48  are formed so as to expose the pad layer  30 .  
         [0030]     In accordance with this invention, it is desirable that the first protective contact hole  47  be formed so as to extend a trench having a predetermined width B along a scribe-line  90  as shown in  FIG. 1 . Alternatively (or, additionally), the scribe-line  90  may be formed to have the first and second protective contact holes  48 . The first and second protective contact holes  48  are preferably formed so as to extend each of two trenches, each having a predetermined width C, along the scribe-line  90  as shown in  FIG. 1 .  
         [0031]     The first and second protective contact holes  48  ( FIG. 5 ) or the first protective contact hole  47  ( FIG. 4 ) may be repeatedly formed along a double ( FIG. 5 ) or a single ( FIG. 4 ) line  49  in a linear sequence to penetrate both the molding layer  40  and the underlying pad layer  30 . As noted above, the first protective contact hole  47  or the first and second protective contact holes  48  are formed to a suitable depth so as to expose the lower layer  20 . In some invention embodiments, the pad layer  30  may not be formed between the molding layer  40  and the lower layer  20 . In this case, the first protective contact hole  47  or the first and second protective contact holes  48  are formed to a suitable depth so as to expose the lower layer  20  through the molding layer  40 .  
         [0032]     It is desirable that the lower layer- 20  be formed by using a material having a greater mechanical intensity (strength) than that of either the pad layer  30  or the molding layer  40 . In one preferred embodiment, the lower layer  20  can be formed using silicon oxide (SiO 2 ). In another preferred embodiment, the molding layer  40  may be formed by using material having a lower mechanical intensity (strength) than that of the pad layer  30 . In one invention embodiment, the pad layer  30  can be formed by using a low-k material selected from the group consisting of Black Diamond, Coral, Aurora, and materials having dielectric constants similar thereto. In another invention embodiment, the pad layer  30  and the molding layer  40  may both be formed by using a lower-k material selected from the group consisting of Nanoporous silicate, BCB, Flare, ALCAP, LKD, and materials having dielectric constants similar thereto. The molding layer  40  may also be composed of two or more lower-k materials. In yet another embodiment, the pad layer  30  may be formed of two or more of the previously described low-k materials or of two or more of the previously described lower-k materials.  
         [0033]     After the formation of the first protective contact hole  47  and/or of the first and second protective contact holes  48 , the photoresist layer  42  is removed from the semiconductor substrate  10  by methods well known in the art.  
         [0034]     Referring now to  FIGS. 1, 6 , and  7 , a portion or portions of the pad layer  30  is (are) exposed through the first protective contact hole  47  and/or the first and second protective contact holes  48 , a dielectric layer  65  may be formed on the exposed portions of pad layer  30  and on the molding layer  40  so as to fill the first protective contact hole  47  or the first and second protective contact holes  48 . It is often desirable that the dielectric layer  65  be formed by using a base layer  50  and a buried layer  60  which are stacked in sequence. The dielectric  65  may also be formed, however, by only using the base layer  50  or only using the buried layer  60 .  
         [0035]     The buried layer  60  and the base layer  50  are preferably formed by using a material or materials having a greater mechanical intensity (strength) than that of the molding layer  40 . It is also often desirable that the buried layer  60  and the base layer  50  be formed by using a low-k material selected from the group consisting of Black Diamond, Coral, Aurora, and materials having dielectric constants similar thereto. In an alternative embodiment, the base layer  50  may be formed by using a low-k material selected from the group consisting of Black Diamond, Coral, Aurora, and materials having dielectric constants similar thereto, while the buried layer  60  is formed by using a lower-k material selected from the group consisting of Nanoporous silicate, BCB, Flare, ALCAP, LKD, and materials having dielectric constants similar thereto. Alternatively, the base layer  50  may be formed by using a lower-k material selected from the group consisting of Nanoporous silicate, BCB, Flare, ALCAP, LKD, and materials having dielectric constants similar thereto, while the buried layer  60  is formed by using a low-k material selected from the group consisting of Black Diamond, Coral, Aurora, and materials having dielectric constants similar thereto. The dielectric layer  65  may also be formed of two or more low-k materials. Furthermore, the dielectric layer  65  may additionally be formed of two or more low-k materials and two or more lower-k materials, as described above, stacked in turn.  
         [0036]     In the case where a portion or portions of the lower layer  20  is (are) exposed through the first protective contact hole  47  or through the first and second protective contact holes  48 , the base layer  50  and the buried layer  60  may be formed on the exposed portions of lower layer  20  and on the molding layer  40  so as to fill the first protective contact hole  47  or the first and second protective contact holes  48 . At this time, the base layer  50  and the buried layer  60  may be formed to have top surfaces as generally indicated by dotted lines  55  and  65 , respectively, as shown in  FIGS. 6 and 7 .  
         [0037]     The buried layer  60  and the base layer  50  should have a greater mechanical intensity (strength) than that of the molding layer  40 , so that, during performance of a cutting process on the semiconductor substrate  10  along a scribe-line  90 , physical shock to the molding layer  40  can be minimized. As a result, the base layer  50  and the buried layer  60  can reduce the number of crack occurrences during cutting along the scribe-line. Furthermore, because the first and second protective contact holes  48  use the molding layer  40  as a shielding layer against physical shock in a central area of the first protective contact hole  47 , crack transference to a peripheral area of the scribe-line  90  can also be minimized.  
         [0038]     Referring now to  FIGS. 1 and 8  to  11 , in the case where the pad layer  30  is exposed through the first protective contact hole  47  or through the first and second protective contact holes  48 , an upper layer  70  may be formed on the dielectric layer  65 . The upper layer  70  may be conformally formed along the top surface of the dielectric layer  65 . The upper layer  70  may be formed, for example, using silicon nitride (Si 3 N 4 ). In the case where the lower layer  20  is exposed through the first protective contact hole  47  or through the first and second protective contact holes  48 , the upper layer  70  can be conformally formed to have a top surface generally indicated by dotted line  75  of  FIG. 8  or  FIG. 9 .  
         [0039]     Protective layer patterns  80  may then be formed on the upper layer  70 . The protective layer patterns  80  are preferably formed so as to be spaced a distance away from each other. It is desirable that the spacing distance A between the protective layer patterns  80  (as seen in  FIG. 10  and  FIG. 11 ) is selected so as to be different from either a contact hole width B of the first protective contact hole  47  or a contact hole width C of the first and second protective contact holes  48 . In a preferred invention embodiment, the protective layer patterns  80  are formed by using polyimide.  
         [0040]     According to the present invention described above, materials having mechanical intensity (strength) different from one another are formed in or along a scribe-line on a semiconductor substrate to create a scribe-line structure, so that, during performance of a cutting process on a semiconductor substrate, mechanical shock or cracking tendencies to a peripheral area of the scribe-line structure may be minimized. As a result, through the cutting process performed on the semiconductor substrate, the use of scribe-line structures according to this invention enables multiple semiconductor devices formed on the same substrate to be separated from one another and from unused semiconductor substrate while minimizing or eliminating damage to the semiconductor devices.  
         [0041]     While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Technology Category: h