Patent Publication Number: US-2009225490-A1

Title: Capacitor structure

Description:
BACKGROUND OF THE INVENTION  
     1. Field of the Invention 
     The present invention relates to a capacitor structure, and more particularly, to a capacitor structure with a greater capacitance. 
     2. Description of the Prior Art 
     A capacitor, a device for storing charges, is normally adopted in various integrated circuits e.g. RFIC and analog circuits. Basically, a capacitor structure includes two opposite electrodes and a dielectric material disposed between the electrodes. The two electrodes are electrically connected to two different voltages, and are separated by the said dielectric material, so the capacitor has the functionality of storing electric charges. U.S. Pat. No. 6,822,312 discloses a conventional flat plate capacitor structures. Please refer to  FIG. 1  to  FIG. 3 .  FIG. 1  is a top view of a conventional interdigitated multilayer (IM) capacitor structure  20  according to U.S. Pat. No. 6,822,312;  FIG. 2  is a perspective view of a section of the conventional IM capacitor structure  20  of  FIG. 1 ; and  FIG. 3  is an end view of the conventional IM capacitor structure  20  section of  FIG. 2 . 
     As shown in  FIG. 1  and  FIG. 2 , the conventional IM capacitor structure  20  is constructed over a substrate  21  of semiconductor material in a multiple conductor level process. The first conductor level  11  includes a first parallel array of electrically conductive horizontal lines  22 , the second conductor level  12  includes a second parallel array of electrically conductive horizontal lines  23 , the third conductor level  13  includes a third parallel array of electrically conductive horizontal lines  24 , and the fourth conductor level  14  includes a fourth parallel array of electrically conductive horizontal lines  25 . A first dielectric layer (not shown) fills the space between the substrate  21  and the first conductor level  11 ; a second dielectric layer  27  fills the space between the first conductor level  11  and the second conductor level  12 ; a third dielectric layer  28  fills the space between the second conductor level  12  and the third conductor level  13 ; and a fourth dielectric layer  29  fills the space between the third conductor level  13  and the fourth conductor level  14 . 
     The four levels  11 ,  12 ,  13 , and  14  of conductive lines  22 ,  23 ,  24  and  25  are aligned over each other in vertical in rows or stacks. The conductive lines  22 ,  23 ,  24  and  25  in each row are electrically interconnected through vertically extending electrically conductive vias  30 ,  31  and  32  formed in the second, third, and fourth dielectric layers  27 ,  28  and  29 . The rows of conductive lines  23 ,  24  and  25  and vias  30 ,  31  and  32  form a parallel array of vertically extending plates  33  which form the electrodes of the conventional IM capacitor structure  20 . The vertically extending plates  33  are electrically interdigitated to opposite polarity by electrically connecting the top or bottom of the vertically extending plates  33  to a first common node A or a second common node B. The first node A and the second node B form the terminals of the conventional IM capacitor structure  20 . 
     As shown in  FIG. 3 , the conventional IM capacitor structure  20  also has a total capacitance which is the sum of all the cross-over capacitance Cc between the vertically extending plates  33  (the sum of the cross-over capacitance between adjacent conductive lines and the cross-over capacitance between adjacent vias) and all the fringing capacitance Cf between the vertically extending plates  33 . The quantity of cross-over capacitance Cc becomes a dominant factor in the capacitor&#39;s total capacitance, while the quantity of fringing capacitance Cf becomes much less significant. 
     However, the capacitor dielectric layer, and these vertically extending plates  33  of the conventional IM capacitor structure  20  are stacked up horizontally, and the overlapping region takes a large layout area for a needed capacitance. Therefore, the layout of the conventional IM capacitor structure  20  reduces the density of integration. 
     SUMMARY OF THE INVENTION  
     It is therefore one object of the present invention to provide a capacitor structure with a greater capacitance. 
     From one aspect of the present invention, a capacitor structure is disclosed. The capacitor structure includes a first electrode, a second electrode and a dielectric material filling a space formed between the first electrode and the second electrode. The first electrode includes a plurality of first meshed conductive structures electrically connecting to each other. Each of the first meshed conductive structures has a layout pattern, and the layout patterns of the first meshed conductive structures are the same. The second electrode includes a plurality of second meshed conductive structures electrically connecting to each other. The first meshed conductive structures and the second meshed conductive structures are alternately stacked, and the first meshed conductive structures do not contact the second meshed conductive structures. Each of the second meshed conductive structures has a layout pattern, and the layout patterns of the second meshed conductive structures are the same. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       The invention can be more fully understood by reading the following detailed description of the preferred embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a top view of a conventional IM capacitor structure; 
         FIG. 2  is a perspective view of a section of the conventional IM capacitor structure of  FIG. 1 ; 
         FIG. 3  is an end view of the conventional IM capacitor structure section of  FIG. 2 ; 
         FIG. 4  shows a top-view schematic diagram of the capacitor structure according to the first preferred embodiment of the present invention; 
         FIG. 5  is a schematic diagram illustrating the layout pattern of the first conductive layer shown in  FIG. 4 ; 
         FIG. 6  is a schematic diagram illustrating the layout pattern of the second conductive layer shown in  FIG. 4 ; 
         FIG. 7  is a schematic diagram illustrating the layout pattern of the plug layer of the capacitor structure according to the first preferred embodiment of the present invention; 
         FIG. 8  shows a top-view schematic diagram of the capacitor structure according to the second preferred embodiment of the present invention; 
         FIG. 9  is a schematic diagram illustrating the layout pattern of the first conductive layer and the related plug layer of the capacitor structure according to the second preferred embodiment of the present invention; 
         FIG. 10  is a schematic diagram illustrating the layout pattern of the second conductive layer shown in  FIG. 8 ; 
         FIG. 11  shows a top-view schematic diagram of the capacitor structure according to the third preferred embodiment of the present invention; 
         FIG. 12  is a schematic diagram illustrating the layout pattern of the first conductive layer and the related plug layer of the capacitor structure according to the third preferred embodiment of the present invention; 
         FIG. 13  is a schematic diagram illustrating the layout pattern of the second conductive layer shown in  FIG. 11 ; 
         FIG. 14  shows a top-view schematic diagram of the capacitor structure according to the fourth preferred embodiment of the present invention; 
         FIG. 15  shows a top-view schematic diagram of the capacitor structure according to the fifth preferred embodiment of the present invention; 
         FIG. 16  is a schematic diagram illustrating the layout pattern of the first conductive layer and the related plug layer of the capacitor structure according to the fifth preferred embodiment of the present invention; 
         FIG. 17  shows a top-view schematic diagram of the capacitor structure according to the sixth preferred embodiment of the present invention; 
         FIG. 18  is a schematic diagram illustrating the layout pattern of the first conductive layer and the related plug layer of the capacitor structure according to the sixth preferred embodiment of the present invention; 
         FIG. 19  shows an oblique schematic diagram of the capacitor structure according to the seventh preferred embodiment of the present invention; 
         FIG. 20  shows an oblique schematic diagram of parts of the capacitor structure according to the eighth preferred embodiment of the present invention; 
         FIG. 21  shows a top-view schematic diagram of the capacitor structure according to the ninth preferred embodiment of the present invention; 
         FIG. 22  is a schematic diagram illustrating the layout pattern of the first conductive layer and the related plug layer of the capacitor structure according to the ninth preferred embodiment of the present invention; 
         FIG. 23  is a schematic diagram illustrating the layout pattern of the second conductive layer and the related plug layer of the capacitor structure according to the ninth preferred embodiment of the present invention; and 
         FIG. 24  is a schematic diagram illustrating the layout pattern of the third conductive layer shown in  FIG. 21 . 
     
    
    
     DETAILED DESCRIPTION  
     Please refer to  FIG. 4  to  FIG. 7 .  FIG. 4  shows a top-view schematic diagram of the capacitor structure  200  according to the first preferred embodiment of the present invention;  FIG. 5  is a schematic diagram illustrating the layout pattern of the first conductive layer  210  shown in  FIG. 4 ;  FIG. 6  is a schematic diagram illustrating the layout pattern of the second conductive layer  230  shown in  FIG. 4 ; and  FIG. 7  is a schematic diagram illustrating the layout pattern of the plug layer of the capacitor structure  200  according to the first preferred embodiment of the present invention, where like numbered numerals designate similar or the same parts, regions or elements. It is to be understood that the drawings are not drawn to scale and are served only for illustration purposes. It is appreciated that the capacitor structure  200  of the present invention is not limited to a two-layer structure formed by stacking the first conductive layer  210  and the second conductive layer  230 , and can be a multi-layer structure including at least three conductive layers, such as a four-layer stacked structure or a six-layer stacked structure. For a multi-layer structure, the layout pattern of a conductive pattern of an odd layer can be identical to the conductive pattern  212  of the first conductive layer  210 , and the layout pattern of a conductive pattern of an even layer can be identical to the conductive pattern  232  of the second conductive layer  230 . 
     As shown in  FIG. 4 , the capacitor structure  200  includes at least a first conductive layer  210  and at least a second conductive layer  230  disposed on the first conductive layer  210 . Both the conductive pattern  212  of the first conductive layer  210  and the conductive pattern  232  of the second conductive layer  230  include conductive rectangular mesh. As shown in  FIG. 5 , the first conductive layer  210  has a conductive pattern  212 , and the conductive pattern  212  includes at least a meshed conductive structure  214  and a plurality of conductive islands  216 . The meshed conductive structure  214  can be formed by a plurality of rectangular conductive rings  218 , and each rectangular conductive ring  218  can form a rectangular mesh  215  respectively. Each conductive island  216  can be disposed in each rectangular mesh  215  and does not contact the meshed conductive structure  214 . The meshed conductive structure  214  can be electrically connected to a first voltage (not shown in the drawings) as a part of the first electrode of the capacitor structure  200 , while all the conductive islands  216  are electrically connected to a second voltage (not shown in the drawings) as a part of the second electrode of the capacitor structure  200 . For example, the first voltage and the second voltage can be a positive voltage and a negative voltage. 
     As shown in  FIG. 6 , the second conductive layer  230  has a conductive pattern  232 . The conductive pattern  232  includes at least a meshed conductive structure  234  and a plurality of conductive islands  236 . The meshed conductive structure  234  can also be formed by a plurality of rectangular conductive rings  238 , and each rectangular conductive ring  238  can form a rectangular mesh  235  respectively. In this embodiment, the conductive pattern  232  and the conductive pattern  212  have the same pattern shape but different orientations (rotated 180 degrees). Thus, the layout pattern of the meshed conductive structure  234  and the layout pattern of the meshed conductive structure  214  can be the same, and the meshed conductive structure  234  is staggered from the meshed conductive structure  214 . Each conductive island  236  can be disposed in each rectangular mesh  235  and does not contact the meshed conductive structure  234 . In contrast between  FIG. 4  and  FIG. 5 , the conductive islands  236  can correspond to corners of the rectangular conductive rings  218  of the meshed conductive structure  214 , while the corners of the rectangular conductive rings  238  of the meshed conductive structure  234  can correspond to the conductive islands  216 . 
     As shown in  FIG. 7 , the capacitor structure  200  further has a plugs layer disposed between the first conductive layer  210  and the second conductive layer  230 . The plugs layer includes a plurality of plugs  252  and a plurality of plugs  254 , such as via plugs or contact plugs. In this embodiment, the plugs  252  can be disposed right under each conductive island  236 . The plugs  252  can contact and electrically connect the meshed conductive structure  214 , such as the corners of the rectangular conductive rings  218 , and the conductive islands  236 . In addition, the plugs  254  can be disposed right above each conductive island  216 , contacting and electrically connecting the meshed conductive structure  234 , such as the corners of the rectangular conductive rings  238 , and the conductive islands  216 . 
     In this embodiment, the second conductive layer  230  and the first conductive layer  210  have similar layout patterns, and the conductive pattern  232  and the conductive pattern  212  are arranged in different orientations. As a result, the meshed conductive structure  214  is staggered from the meshed conductive structure  234 . Specifically speaking, there are two offsets between the position of the meshed conductive structure  234  and the position of the meshed conductive structure  214  in two directions along the length and the width of the rectangular conductive ring  218  respectively. Thus, the meshed conductive structure  234  of the second conductive layer  230 , the conductive islands  216  of the first conductive layer  210 , and the plugs  254  disposed between the meshed conductive structure  234  and the conductive islands  216  are electrically connected to each other as the second electrode of the capacitor structure  200 . On the other hand, the conductive islands  236  of the second conductive layer  230 , the meshed conductive structure  214  of the first conductive layer  210 , and the plugs  252  disposed between the meshed conductive structure  214  and the conductive islands  236  are electrically connected to each other as the first electrode of the capacitor structure  200 . 
     Accordingly, the capacitor structure  200  of the present invention can provide a grater capacitance in the unit volume. The capacitance of the capacitor structure  200  is contributed to by the vertical capacitance between the first conductive layer  210  and the second conductive layer  230 , the horizontal capacitance between the meshed conductive structure  214  and the conductive islands  216 , the horizontal capacitance between the meshed conductive structure  234  and the conductive islands  236 , and the horizontal capacitance between the plugs  252  and the plugs  254 . 
     One of the characteristics of the present invention is that the electrode of the capacitor structure has the meshed conductive structure, and there are conductive islands having different polarities inside the meshed conductive structure to provide the horizontal capacitance. It should be noted that the layouts and the shapes of the conductive patterns and the plugs should not be limited to the above-mentioned embodiment, and the layouts and the shapes can be adjusted to be various shapes, such as triangular shape, circular shape, pentagonal shape, hexagonal shape, octagonal shape or parallelogram. Please refer to  FIG. 8  to  FIG. 10 .  FIG. 8  shows a top-view schematic diagram of the capacitor structure  300  according to the second preferred embodiment of the present invention;  FIG. 9  is a schematic diagram illustrating the layout pattern of the first conductive layer  310  and the related plug layer of the capacitor structure  300  according to the second preferred embodiment of the present invention; and  FIG. 10  is a schematic diagram illustrating the layout pattern of the second conductive layer  330  shown in  FIG. 8 , where like numbered numerals designate similar or the same parts, regions or elements. As shown in  FIG. 8 , it is a difference from the first embodiment that both the conductive pattern  312  of the first conductive layer  310  and the conductive pattern  332  of the conductive layer second  330  include conductive triangular meshes  314 ,  334  in the second embodiment. 
     As shown in  FIG. 9 , the first conductive layer  310  has a conductive pattern  312 , and the conductive pattern  312  includes at least a meshed conductive structure  314  and a plurality of conductive islands  316 . The meshed conductive structure  314  can be formed by a plurality of triangular conductive rings  318 . 
     As shown in  FIG. 10 , the second conductive layer  330  has a conductive pattern  332 , and the conductive pattern  332  includes at least a meshed conductive structure  334  and a plurality of conductive islands  336 . The second conductive layer  230  and the first conductive layer  210  have similar layout patterns, and the meshed conductive structure  334  is staggered from the meshed conductive structure  314 . For instance, there are two offsets between the position of the meshed conductive structure  334  and the position of the meshed conductive structure  314  in two directions along two edges of the triangular conductive ring  318  respectively. As a result, the conductive islands  336  can correspond to corners of the triangular conductive rings  318  of the meshed conductive structure  314 , while the corners of the triangular conductive rings  318  of the meshed conductive structure  334  can correspond to the conductive islands  316 . 
     In contrast among  FIG. 8 ,  FIG. 9  and  FIG. 10 , each conductive island  316  of the first conductive layer  310  can contact at least a plug  254  thereon, and each conductive island  336  of the second conductive layer  330  can contact at least an underlying plug  252 . Thus, the meshed conductive structure  334  of the second conductive layer  330 , the conductive islands  316  of the first conductive layer  310 , and the plugs  254  disposed between the meshed conductive structure  334  and the conductive islands  316  are electrically connected to each other as the second electrode of the capacitor structure  300 . On the other hand, the conductive islands  336  of the second conductive layer  330 , the meshed conductive structure  314  of the first conductive layer  310 , and the plugs  252  disposed between the meshed conductive structure  314  and the conductive islands  336  are electrically connected to each other as the first electrode of the capacitor structure  300 . 
     In the above two embodiments, the meshed conductive structures, which are vertically adjacent, have the similar layout patterns and are staggered from each other. In order to take more advantage of the space in the integrated circuit, the meshed conductive structures, which are vertically adjacent, can have different layout patterns in other embodiments of the present invention. Accordingly, there can be at least a conductive island in each conductive ring to effectively increase the electrode area of the capacitor structure. Please refer to  FIG. 11  to  FIG. 13 . It is a difference from the second embodiment that the conductive pattern of the first conductive layer  410  includes conductive hexagonal meshes in the third embodiment. 
     As shown in  FIG. 12 , the first conductive layer  410  has a conductive pattern  412 , and the conductive pattern  412  includes at least a meshed conductive structure  414  and a plurality of conductive islands  416 . The meshed conductive structure  414  can be formed by a plurality of hexagonal conductive rings  418 . Each hexagonal conductive ring  418  can form a hexagonal mesh respectively. Each conductive island  416  can be disposed in each hexagonal mesh and does not contact the meshed conductive structure  414 . 
     As shown in  FIG. 13 , the second conductive layer  430  has a conductive pattern  432 , and the conductive pattern  432  includes at least a meshed conductive structure  434  and a plurality of conductive islands  436 . The meshed conductive structure  434  can be formed by a plurality of triangular conductive rings  318 , and each triangular conductive ring  318  can form a triangular mesh respectively. Each conductive island  436  can be disposed in each triangular mesh and does not contact the meshed conductive structure  434 . For example, the conductive islands  436  can correspond to corners of the hexagonal conductive rings  418  of the meshed conductive structure  414 , while corners of the triangular conductive rings  318  can correspond to the conductive islands  416 . 
     In addition, in contrast between  FIG. 12  and  FIG. 13 , the capacitor structure  400  has a plug layer disposed between the first conductive layer  410  and the second conductive layer  430 . The meshed conductive structure  434  of the second conductive layer  430 , the conductive islands  416  of the first conductive layer  410 , and the plugs  254  disposed between the meshed conductive structure  434  and the conductive islands  416  are electrically connected to each other as the second electrode of the capacitor structure  400 . On the other hand, the conductive islands  436  of the second conductive layer  430 , the meshed conductive structure  414  of the first conductive layer  410 , and the plugs  252  disposed between the meshed conductive structure  414  and the conductive islands  436  are electrically connected to each other as the first electrode of the capacitor structure  400 . 
     Furthermore, the conductive patterns of the capacitor structure should not be limited to the conductive pattern including merely the meshed conductive structure and the conductive islands in the present invention. In practice, the conductive patterns can further include conductive structures having other shapes. For example, the conductive pattern of some layers can further include conductive bars. Please refer to  FIG. 14 , which shows a top-view schematic diagram of the capacitor structure  500  according to the fourth preferred embodiment of the present invention. It is a difference from the first embodiment that many major conductive bars  534  are included in the fourth embodiment in place of the meshed conductive structure  234  of the first embodiment. Comparing with the continuous meshed structure, the conductive bars can decrease the structural stress of the capacitor structure. 
     As shown in  FIG. 14 , the second conductive layer  530  has a conductive pattern  532 , and the conductive pattern  532  includes a plurality of major conductive bars  534  and a plurality of conductive islands  536 . Some of the major conductive bars  534   a  can be parallel with the length direction of the rectangular conductive ring  218  of the first conductive layer  510 , and some of the major conductive bars  534   b  are parallel with the width direction of the rectangular conductive ring  218  of the first conductive layer  510 . A major conductive bar  534   a  and a major conductive bar  534   b  can form a separated conductive structure having a L-shape. The conductive islands  536  can correspond to corners of the rectangular conductive ring  218  of the meshed conductive structure  214 , while the intersections of the major conductive bars  534   a  and the major conductive bars  534   b  can correspond to the conductive islands (not shown in the drawings) of the first conductive layer  510 . The major conductive bars  534  can be disposed around each conductive island  536 . 
     Accordingly, the conductive islands  536  do not contact the major conductive bars  534 . The conductive islands  536  can be electrically connected to the meshed conductive structure  214  through the underlying plugs (not shown in the drawings) to form the first electrode of the capacitor structure  500 . Meanwhile, the conductive islands (not shown in the drawings) of the first conductive layer  510  can be electrically connected to the major conductive bars  534  through the upper plugs (not shown in the drawings) to form the second electrode of the capacitor structure  500 . 
     In addition, the major conductive bars  534  of the second conductive layer  530  can have other layout arrangements in other embodiments of the present invention. Please refer to  FIG. 15  to  FIG. 18 . 
     As  FIG. 15  and  FIG. 16  show, the first conductive layer  610  has a conductive pattern  612 , and the conductive pattern  612  includes at least a meshed conductive structure  614  and a plurality of conductive islands  616 . The second conductive layer  630  has a conductive pattern  632 , and the conductive pattern  632  includes a plurality of the major conductive bars  634  and a plurality of conductive islands  636 . Some of the major conductive bars  634   a  can be parallel with the length direction of the rectangular conductive rings  218  of the first conductive layer  610 , and the major conductive bars  634   a  can be abreast of each other. Some of the major conductive bars  634   b  can be disposed between the conductive bars  634 , be parallel with the width direction of the rectangular conductive rings  218  of the first conductive layer  610 , and be abreast of each other. Each of the major conductive bars  634  can correspond to at least an underlying plug  254 , each of the plugs  254  can correspond to an underlying conductive island  616 , and each of the major conductive bars  634 , each of the plugs  254 , and each of the conductive islands  616  can be electrically connected to the second voltage to form the second electrode of the capacitor structure  600 . On the other hand, the conductive islands  636  can be electrically connected to the meshed conductive structure  614  through of the underlying plugs  252  to form the first electrode of the capacitor structure  600 . 
     As shown in  FIG. 17  and  FIG. 18 , the first conductive layer  710  has a conductive pattern  712 , and the conductive pattern  712  includes at least a meshed conductive structure  714  and a plurality of conductive islands  716 . The second conductive layer  730  has a conductive pattern  732 , and the conductive pattern  732  includes a plurality of the major conductive bars  734  and a plurality of conductive islands  736 . Each of the major conductive bars  734  can correspond to an underlying plug  254 , each of the plugs  254  can correspond to an underlying conductive island  716 , and each of the major conductive bars  734 , each of the plugs  254 , and each of the conductive islands  716  can be electrically connected to the second voltage to form the second electrode of the capacitor structure  700 . On the other hand, the conductive islands  736  can be electrically connected to the meshed conductive structure  714  through of the underlying plugs  252  to form the first electrode of the capacitor structure  700 . 
     As the mentioned above, the capacitor structure of the present invention is not limited to a two-layer structure formed by stacking the first conductive layer and the second conductive layer, and can be a multi-layer structure, such as a three-layer stacked structure formed by stacking the first, the second and the third conductive layers. Please refer to  FIG. 19 , which shows an oblique schematic diagram of the capacitor structure  800  according to the seventh preferred embodiment of the present invention, where like numbered numerals designate similar or the same parts, regions or elements. 
     As shown in  FIG. 19 , the capacitor structure  800  includes at least a first conductive layer  810 , at least a second conductive layer  830  and at least a third conductive layer  870 . The second conductive layer  830  is disposed on the first conductive layer  810 , and the third conductive layer  870  is disposed on the second conductive layer  830 . The conductive pattern of the first conductive layer  810 , the conductive pattern of the second conductive layer  830  and the conductive pattern of the third conductive layer  870  in the seventh embodiment can be identical to the conductive pattern  212  of the first conductive layer  210  in the first embodiment, the conductive pattern  232  of the second conductive layer  230  in the first embodiment, and the conductive pattern  532  of the second conductive layer  530  in the fourth embodiment respectively. Accordingly, the plugs  252  and the plugs  254  disposed between the first conductive layer  810  and the second conductive layer  830  in the seventh embodiment can be identical to the plugs  252  and the plugs  254  of the first embodiment, and the plugs  252  and the plugs  254  disposed between the second conductive layer  830  and the third conductive layer  870  in the seventh embodiment can be identical to the plugs  252  and the plugs  254  of the fourth embodiment. 
     The meshed conductive structure  214  of the first conductive layer  810 , the conductive islands  236  of the second conductive layer  830 , the major conductive bars  534  of the third conductive layer  870 , and the plugs  252  disposed between them are electrically connected to each other to form the first electrode of the capacitor structure  800 . On the other hand, the conductive islands  216  of the first conductive layer  810 , the meshed conductive structure  234  of the second conductive layer  830 , the conductive islands  536  of the third conductive layer  870 , and the plugs  254  disposed between them are electrically connected to each other to form the second electrode of the capacitor structure  800 . 
     Since the capacitor structure  800  is an odd-layer structure formed by stacking the first, the second and the third conductive layers, it appreciated that the meshed conductive structures of odd layers can be staggered to the meshed conductive structures of even layers when more conductive layers are stacked above to increase the capacitance. Accordingly, the meshed conductive structures of odd layers can be electrically connected to each other vertically, and the meshed conductive structures of even layers can also be electrically connected to each other vertically. Thus, the capacitance can be improved, and the capacitor structure can have a good matching structure. Please refer to  FIG. 20 , which shows an oblique schematic diagram of parts of the capacitor structure  801  according to the eighth preferred embodiment of the present invention, where like numbered numerals designate similar or the same parts, regions or elements. It is worthy of note that the dialectical material of the capacitor structure, some of the conductive islands and some of the plugs are omitted in  FIG. 20  for clearly illustrating the relative positions among the meshed conductive structure and the major conductive bars, so only the meshed conductive structures, the major conductive bars, some of the conductive islands and some of the plugs of the capacitor structure  801  are shown in  FIG. 20 . 
     As shown in  FIG. 20 , the capacitor structure  801  includes at least a first conductive layer  810 , at least a second conductive layer  830 , at least a third conductive layer  870 , at least a fourth conductive layer  811 , at least a fifth conductive layer  831  and at least a sixth conductive layer  871  from bottom to top. The conductive pattern of the fourth conductive layer  811 , the conductive pattern of the fifth conductive layer  831 , and the conductive pattern of the sixth conductive layer  871  can be identical to the conductive pattern  212 , the conductive pattern  232  and the conductive pattern  532  respectively. The meshed conductive structure  214  of the fourth conductive layer  811  is staggered from the meshed conductive structure  214  of the first conductive layer  810 ; the meshed conductive structure  234  of the fifth conductive layer  831  is staggered from the meshed conductive structure  234  of the second conductive layer  830 ; and the major conductive bars  534  of the sixth conductive layer  871  are staggered from the major conductive bars  534  of the third conductive layer  870 . 
     The meshed conductive structure  214  of the first conductive layer  810 , the conductive islands  236  of the second conductive layer  830 , the major conductive bars  534  of the third conductive layer  870 , the conductive islands  216  of the fourth conductive layer  811 , the meshed conductive structure  234  of the fifth conductive layer  831 , the conductive islands  236  of the sixth conductive layer  871 , and the plugs  252  disposed between them are electrically connected to each other to form the first electrode of the capacitor structure  801 . On the other hand, the conductive islands  216  of the first conductive layer  810 , the meshed conductive structure  234  of the second conductive layer  830 , the conductive islands  536  of the third conductive layer  870 , the meshed conductive structure  214  of the fourth conductive layer  811 , the conductive islands  236  of the fifth conductive layer  831 , the major conductive bars  534  of the sixth conductive layer  871 , and the plugs  254  disposed between them are electrically connected to each other to form the second electrode of the capacitor structure  800 . 
     In other embodiments of the present invention, the first conductive layer, the second conductive layer and the third conductive layer can have three different conductive patterns respectively. Please refer to  FIG. 21  to  FIG. 24 . 
     As shown in  FIG. 21 , the capacitor structure  900  includes a first conductive layer  910  and a second conductive layer  930  and a third conductive layer  970  from bottom to top. As shown in  FIG. 22  and  FIG. 23 , the conductive pattern of the first conductive layer  910  and the conductive pattern of the second conductive layer  930  in the ninth embodiment can be identical to the conductive pattern of the first conductive layer  410  and the conductive pattern of the conductive layer  430  in the third embodiment respectively. Accordingly, the plugs  252  and the plugs  254  disposed between the first conductive layer  910  and the second conductive layer  930  in the ninth embodiment can have same layout pattern with the plugs  252  and the plugs  254  in the third embodiment. 
     As shown in  FIG. 24 , the third conductive layer  970  has a conductive pattern  972 , and the conductive pattern  972  includes a plurality of major conductive bars  974 , which are parallel with each other, and a plurality of conductive islands  976 . In contrast among  FIG. 21 ,  FIG. 22 ,  FIG. 23  and  FIG. 24 , the major conductive bars  974  of the third conductive layer  970  can correspond to the conductive islands  436  of the second conductive layer  430 , and each conductive island  976  of the third conductive layer  970  can correspond to each conductive island  416  of the first conductive layer  410  respectively. 
     Accordingly, each of the major conductive bars  974  of the third conductive layer  970  can be electrically connected to the conductive islands  436  of the second conductive layer  930  through the underlying plugs  252 , and each of the conductive islands  436  of the second conductive layer  930  can be electrically connected to the meshed conductive structure  414  of first conductive layer  410  through the underlying plugs  252  to form the first electrode of the capacitor structure  900 . On the other hand, each of the conductive islands  976  of the third conductive layer  970  can be electrically connected to the meshed conductive structure  434  of the second conductive layer  930  through the underlying plugs  254 , the meshed conductive structure  434  of the second conductive layer  930  can be electrically connected to the conductive islands  416  of the first conductive layer  410  through the underlying plugs  254  to form the second electrode of the capacitor structure  900 . 
     Thus, the shape, size, and arranged density of the plugs are not limited by the above-mentioned configurations and can be modified to obtain an optimal capacitance and a great matching. It should be understood by a person skilled in the art that the present invention can further include a dielectric material or a plurality of dielectric layers (not shown in the drawings) to fill a space between the first electrode and the second electrode as the dielectric layer of the capacitor structure. However, for clearly illustrating the electrode structure of the present invention, the dielectric material is not shown in the drawings. Furthermore, the capacitor structure of the present invention can include two I/O ports (not shown in the drawings) for external connections. In addition, the fabrication of the capacitor structure of the present invention can be integrated into the metal interconnection process. In such a case, the conductive pattern can be made from metal materials e.g. aluminum or copper, or other conductive materials, such as polycrystalline silicon. The material of the contact plugs can be tungsten, copper, aluminum, etc. The dielectric layer may be silicon oxide, silicon nitride, silicon oxynitride, or any single or composite dielectric materials. 
     The capacitance of the capacitor is contributed by the vertical capacitance between the conductive patterns, the horizontal capacitance between the meshed conductive structures and the conductive islands in each layer, the horizontal capacitance between the major conductive bars and the conductive islands in each layer, and the horizontal capacitance between the plugs, and therefore the capacitance of the capacitor structure in unit volume can be effectively improved. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.