TWI831224B - Metal-oxide-metal capacitor structure - Google Patents

Abstract

The disclosure provides a metal-oxide-metal capacitor structure, which includes at least a first finger electrode structure and a second finger electrode structure. The first finger electrode structure includes a plurality of first metal lines and a first electrode. The first metal lines extend along a first direction, and the first electrode extends along a second direction and is connected to the first metal lines. The second finger electrode structure includes a plurality of second metal lines and a second electrode. The second metal lines extend along the first direction, and the second electrode extends along the second direction and is connected to the second metal lines. The first metal lines and the second metal lines are staggered each other and arranged between the first electrodes and the second electrodes, so that each first metal line is located between every two adjacent second metal lines.

Description

Metal oxide metal capacitor structure

This case relates to a semiconductor capacitor structure, specifically a metal oxide metal (MOM) capacitor structure.

Capacitors usually play an important role in the layout of integrated circuits, and metal oxide capacitor structures are widely used because of their low capacitance leakage. FIG. 1 is a schematic structural diagram of a conventional metal oxide metal capacitor structure. As shown in FIG. 1 , the conventional metal oxide metal capacitor structure 40 includes a first finger-like electrode structure 42 and a second finger-like electrode structure 44. The first The finger electrode structure 42 includes a plurality of first metal lines 421, the second finger electrode structure 44 includes a plurality of second metal lines 441, and the first metal lines 421 and the second metal lines 441 are interlaced with each other to present the first A staggered structure of metal lines 421, second metal lines 441, first metal lines 421, second metal lines 441....

In the conventional technology, as shown in Figure 2, when two metal oxide metal capacitor structures 40 and 40' are arranged together, in order to comply with the spacing rule (Spacing Rule), the metal oxide metal capacitor structure 40 and the metal oxide metal capacitor structure 40 are arranged together. The distance between the capacitor structures 40' must maintain a fixed distance D and cannot be reduced. Furthermore, if there are two or more metal oxide metal capacitor structures 40, 40', the third one as the positive terminal One finger electrode structure 42, 42' needs to receive different signals, and the second finger electrode structure 44, 44' serving as the negative terminal needs to receive the same signal. At this time, because the first metal line 421, 421' or the second metal line 441 , 441' cannot be shared and the existence of fixed spacing D increases the use of the overall area, and there are many restrictions on the arrangement, which cannot cope with the downward shrinkage of semiconductor dimensions and the increase in circuit density.

This application provides a metal oxide metal capacitor structure, including at least a first finger-shaped electrode structure and a second finger-shaped electrode structure. The first finger electrode structure includes a plurality of first metal lines and a first electrode. The first metal lines extend along a first direction. The first electrode extends along a second direction and connects the first metal lines. . The second finger electrode structure includes a plurality of second metal lines and a second electrode. The second metal lines extend along the first direction. The second electrode extends along the second direction and connects the second metal lines. The first metal lines and the second metal lines are interlaced and arranged side by side between the first electrode and the second electrode, so that each first metal line is located between every two adjacent second metal lines.

This case also provides a metal oxide metal capacitor structure, including a plurality of first finger electrode structures and a second finger electrode structure. Each first finger electrode structure includes a plurality of first metal lines and a first electrode. The first metal lines extend along a first direction. The first electrode extends along a second direction and connects the first electrodes. metal wire. The second finger electrode structure includes a plurality of second metal lines and a second electrode. The second metal lines extend along the first direction. The second electrode extends along the second direction and connects the second metal lines. As a common electrode, all the first metal lines and the second metal lines are interlaced with each other and located between the first electrode and the second electrode, so that each first metal line is located between every two adjacent second metal lines. between lines.

In some embodiments, the sum of a first total number of all the first metal lines and a second total number of the second metal lines is an odd number.

In some embodiments, the first direction is perpendicular to the second direction.

In some embodiments, each first electrode is a positive electrode and each second electrode is a negative electrode. Alternatively, each first electrode is a negative electrode and the second electrode is a positive electrode.

In some embodiments, the first finger-shaped electrode structures can be connected to another first finger-shaped electrode structure of another electrode layer through a plurality of first via holes; and the second finger-shaped electrode structure can be connected to another first finger-shaped electrode structure through a plurality of first via holes. The two via holes are connected to another second finger electrode structure of another electrode layer.

In some embodiments, the first metal lines have the same distance from each other, and the second metal lines have the same distance from each other, and the first metal lines and the second metal lines are staggered and side by side. They are also at the same distance from each other.

In some embodiments, the first finger-shaped electrode structures may be located on two opposite sides of the second finger-shaped electrode structure respectively, so as to share the second finger-shaped electrode structure.

In summary, with the downward shrinkage of semiconductor dimensions and the increase in circuit density, this project proposes a metal oxide metal capacitor structure with a common second finger electrode structure, so that it can effectively maintain the same capacitance. Reduce the occupied integrated circuit area. Moreover, in this case, when two or more metal oxide metal capacitor structures are arranged, the shared second finger-shaped electrode structure helps to reduce the area, and the arrangement is also more flexible. Based on this, under the condition that the size and area of the chip (chip) is shrinking day by day, this case helps to reduce the use of area to obtain the same capacitance, so as to improve the area utilization rate.

Preferred embodiments are provided below for detailed description. However, the embodiments are only used as examples and will not limit the scope of the present case. In addition, some components or structures are omitted in the drawings of the embodiments to clearly illustrate the technical features of the present invention. In the drawings, the same reference numbers refer to the same or similar elements or circuits, it is understood that although the terms "first", "second", etc. may be used herein to describe various elements, components, regions or functions , but these elements, components, regions and/or functions should not be limited by these terms, which are only used to distinguish one element, component, region or function from another element, component, region or function.

Figure 3 is a schematic structural diagram of a metal oxide metal capacitor structure according to an embodiment of the present invention. Please refer to Figure 3. As shown in Figure 3, a metal oxide metal capacitor structure 10 includes at least a first finger-shaped electrode structure 12 and a second finger-shaped electrode structure. The electrode structure 14, in this embodiment, takes a first finger-shaped electrode structure 12 as an example. The first finger electrode structure 12 includes a plurality of first metal lines 121 and a first electrode 122. The first metal lines 121 are parallel to each other and extend along a first direction. The first electrode 122 extends along a second direction. And connect the first metal lines 121 . The second finger electrode structure 14 includes a plurality of second metal lines 141 and a second electrode 142. The second metal lines 141 are parallel to each other and extend along the first direction. The second electrode 142 extends along the second direction and is connected. The second metal lines 141, the first metal lines 121 and the second metal lines 141 are staggered and arranged side by side and are located between the first electrode 122 and the second electrode 142, so that each first metal line 121 is located between every two adjacent second metal lines 141 . The first direction is perpendicular to the second direction, so that the first electrode 122 is vertically connected to the first metal line 121 and the second electrode 142 is vertically connected to the second metal line 141 .

As shown in FIG. 3 , the first metal lines 121 in the first finger electrode structure 12 have the same distance from each other, and the second metal lines 141 in the second finger electrode structure 14 have the same distance from each other. , and the first metal wires 121 and the second metal wires 141 that are staggered side by side also have the same distance from each other, so that the first metal wires 121 and the second metal wires 141 are not connected to each other.

Wherein, in the metal oxide metal capacitor structure 10 , the sum of a first total number of all first metal lines 121 and a second total number of all second metal lines 141 is an odd number (odd number). In the present embodiment as shown in FIG. 3 , the first total number of the first metal lines 121 is 4, and the second total number of the second metal lines 141 is 5. Therefore, the first total number and the second total number are The sum is 9, which is an odd number. Furthermore, since the second total number of the second metal lines 141 is greater than the first total number of the first metal lines 121, each first metal line 121 can be positioned between every two adjacent second metal lines 141. space, and two of the second metal lines 141 will be located on the outermost side.

In one embodiment, the materials of the first finger electrode structure 12 (including the first metal line 121 and the first electrode 122) and the second finger electrode structure 14 (including the second metal line 141 and the second electrode 142) can be It can be any metal material suitable for making capacitor structures, such as aluminum, copper, silver, tungsten, etc., but this case is not limited to this.

In one embodiment, the first electrode 122 is a positive electrode, and the second electrode 142 is a negative electrode, so that they have opposite electrical properties. In another embodiment, the first electrode 122 is a negative electrode, and the second electrode 142 is a positive electrode, so that the electrical terminal positions are exchanged according to design requirements.

In addition to being a two-dimensional capacitor structure, the metal oxide capacitor structure 10 of the present application can also be a three-dimensional stacked capacitor structure, which includes more than two electrode layers, such as three layers. , four or more floors. The metal oxide metal capacitor structure 10 includes a first electrode layer 16 and a second electrode layer 16'. This embodiment takes an electrode layer with two layers as an example for detailed description. Please refer to the first electrode layer 16 shown in Figure 4. It includes a first finger electrode structure 12 and a second finger electrode structure 14. The second electrode layer 16' is located under the first electrode layer 16, and the second electrode layer 16' includes the first finger electrode structure 12' and a second finger electrode structure 14. Finger electrode structure 14'. Among them, the first finger electrode structure 12 of the first electrode layer 16 is connected to the first finger electrode structure 12' of the second electrode layer 16' through a plurality of first vias (vias) 18, so that the first finger electrode The structures 12 and 12' both have the same electrical polarity; the second finger-shaped electrode structure 14 of the first electrode layer 16 can also be connected to the second finger-shaped electrode structure of the second electrode layer 16' through a plurality of second via holes 20. 14', so that the second finger electrode structures 14 and 14' share the same electrical polarity. For the remaining detailed structures of the first finger electrode structures 12, 12' and the second finger electrode structures 14, 14', please refer to the foregoing description and will not be repeated here.

In one embodiment, as shown in FIG. 4 , the layout structure and number of the first finger electrode structures 12 and the second finger electrode structures 14 of the first electrode layer 16 are the same as those of the first fingers of the second electrode layer 16 ′. The finger-shaped electrode structure 12' is the same as the second finger-shaped electrode structure 14', and if the metal oxide metal capacitor structure 10 of this case includes more than two electrode layers, such as three layers, four layers or more layers, each electrode layer will have the same layout structure and quantity.

Figure 5 is a schematic structural diagram of a metal oxide metal capacitor structure according to another embodiment of the present invention. Please refer to Figure 5. As shown in Figure 5, a metal oxide metal capacitor structure 10 includes a plurality of first finger electrode structures 12, 22, 24 and a The second finger electrode structure 14, in this embodiment, takes three first finger electrode structures 12, 22, and 24 as an example. The first finger electrode structure 12 includes a plurality of first metal lines 121 and a first electrode 122. The first metal lines 121 are parallel to each other and extend along the first direction. The first electrode 122 extends along the second direction and is vertical. Connect the first metal lines 121 . The first finger electrode structure 22 is located on one side of the first finger electrode structure 12. The first finger electrode structure 22 includes a plurality of first metal lines 221 and a first electrode 222. The first metal lines 221 are parallel to each other and along the The first electrode 222 extends along the first direction and vertically connects the first metal lines 221 along the second direction. The first finger electrode structure 24 is located on one side of the first finger electrode structure 22. The first finger electrode structure 24 includes a plurality of first metal lines 241 and a first electrode 242. The first metal lines 241 are parallel to each other and along the The first electrode 242 extends along the first direction and vertically connects the first metal lines 241 along the second direction. The second finger electrode structure 14 includes a plurality of second metal lines 141 and a second electrode 142. The second metal lines 141 are parallel to each other and extend along the first direction. The second electrode 142 extends along the second direction and is connected. The second metal lines 141 serve as common electrodes. All the first metal lines 121, 221, 241 and all the second metal lines 141 are staggered and arranged side by side and are respectively located at the first electrodes 122, 222, 242 and the second electrode 142. so that each first metal line 121, 221, 241 is located between every two adjacent second metal lines 141.

As shown in FIG. 5 , all the first metal lines 121 , 221 , and 241 in the first finger electrode structures 12 , 22 , and 24 have the same distance from each other, and the second metal lines 121 , 221 , and 241 in the second finger electrode structure 14 have the same distance from each other. The metal wires 141 are at the same distance from each other, and the staggered first metal wires 121, 221, 241 and the second metal wires 141 are also at the same distance from each other, so that the first metal wires 121, 221, 241 and the second metal wires 141 are at the same distance from each other. The metal wires 141 are not connected to each other.

In the metal oxide metal capacitor structure 10 , the sum of a first total number of all first metal lines 121 , 221 , 241 and a second total number of all second metal lines 141 is an odd number. In the embodiment shown in FIG. 5 , the number of the first metal wires 121 is 4, the number of the first metal wires 221 is 4, and the number of the first metal wires 241 is 4, so the first total number is 12. The second total number of the second metal wires 141 is 13, so the sum of the first total number and the second total number is 25, which is an odd number. Furthermore, since the second total number of the second metal lines 141 is greater than the first total number of all the first metal lines 121, 221, 241, each first metal line 121, 221, 241 can be located at every two Between the adjacent second metal lines 141, and two of the second metal lines 141 will be located on the outermost side, the middle second metal line 141' is shared by the first finger electrode structures 12 and 22, and the middle second metal line 141' is shared by the first finger electrode structures 12 and 22. The two metal lines 141″ are shared by the first finger electrode structures 22 and 24.

In one embodiment, if the positive terminal of the metal oxide metal capacitor structure 10 is to be connected to the same signal and the negative terminal is to be connected to different signals, then the first electrodes 122, 222, and 242 are negative electrodes respectively, and the second electrode 142 is Common positive pole. If the positive terminals of the metal oxide metal capacitor structure 10 are connected to different signals and the negative terminals are connected to the same signal, then the first electrodes 122, 222, and 242 are respectively positive electrodes, and the second electrode 142 is a common negative electrode.

Figure 6 is a schematic structural diagram of a metal oxide metal capacitor structure according to another embodiment of the present invention. Please refer to Figure 6. As shown in Figure 6, a metal oxide metal capacitor structure 10 includes a plurality of first finger electrode structures 12, 22, 24, 26, 28, 30 and a second finger-like electrode structure 14. In this embodiment, six first finger-like electrode structures 12, 22, 24, 26, 28, 30 are taken as an example, and they are respectively located at the second The two opposite sides of the finger electrode structure 14 share the second finger electrode structure 14 . As shown in FIG. 6 , the first finger electrode structure 12 includes a plurality of first metal lines 121 and a first electrode 122 . The first metal lines 121 are parallel to each other and extend along the first direction. The first electrode 122 extends along the first direction. The second direction extends and vertically connects the first metal lines 121 . The first finger electrode structure 22 is located on one side of the first finger electrode structure 12. The first finger electrode structure 22 includes a plurality of first metal lines 221 and a first electrode 222. The first metal lines 221 are parallel to each other and Extending along the first direction, the first electrode 222 extends along the second direction and vertically connects the first metal lines 221 . The first finger electrode structure 24 is located on one side of the first finger electrode structure 22. The first finger electrode structure 24 includes a plurality of first metal lines 241 and a first electrode 242. The first metal lines 241 are parallel to each other. Extending along the first direction, the first electrode 242 extends along the second direction and vertically connects the first metal lines 241 . The first finger electrode structure 26 is symmetrical to the first finger electrode structure 12. The first finger electrode structure 26 includes a plurality of first metal lines 261 and a first electrode 262. The first metal lines 261 are parallel to each other and along the The first electrode 262 extends along the second direction and vertically connects the first metal lines 261 . The first finger electrode structure 28 is located on one side of the first finger electrode structure 26 and is symmetrical to the first finger electrode structure 22. The first finger electrode structure 28 includes a plurality of first metal lines 281 and a first electrode 282. The first metal lines 281 are parallel to each other and extend along the first direction. The first electrodes 282 extend along the second direction and are vertically connected to the first metal lines 281 . The first finger electrode structure 30 is located on one side of the first finger electrode structure 28 and is symmetrical to the first finger electrode structure 24. The first finger electrode structure 30 includes a plurality of first metal lines 301 and a first electrode 302. The first metal lines 301 are parallel to each other and extend along the first direction. The first electrodes 302 extend along the second direction and are vertically connected to the first metal lines 301 . The second finger electrode structure 14 is located between the first finger electrode structures 12, 22, 24 and the first finger electrode structures 26, 28, 30. The second finger electrode structure 14 includes a plurality of second metal lines 141 and a The second electrode 142, the second metal lines 141 are parallel to each other and extend along the first direction. The second electrode 142 extends along the second direction and is vertically connected between the second metal lines 141, so that the first finger-shaped The electrode structures 12, 22, 24 and the first finger electrode structures 26, 28, 30 are respectively located on opposite sides of the second electrode 142 to serve as a common electrode. The first metal lines 121, 221, 241 and the second metal lines The upper half of the first metal lines 261, 281, 301 and the second metal line 141 are interlaced with each other and are located between the first electrodes 122, 222, 242 and the second electrode 142 respectively. staggered and arranged side by side between the first electrodes 262, 282, 302 and the second electrode 142, so that each first metal line 121, 221, 241, 261, 281, 301 is located between every two adjacent second metal lines 141 between.

As shown in FIG. 6 , since the first finger electrode structures 12 , 22 , 24 and the first finger electrodes 26 , 28 , 30 are respectively located on the upper and lower opposite sides of the second finger electrode structure 14 , they can share the second finger electrode structure 14 . The finger electrode structure 14 reduces the layout of the second finger electrode structure 14 to reduce the area and winding space.

In the embodiment shown in FIG. 6 , the number of the first metal lines 121 located in the upper half is 4, the number of the first metal lines 221 is 4, and the number of the first metal lines 241 is 4. The number of the first metal lines 241 located in the lower half is 4. The number of the first metal wires 261 is 4, the quantity of the first metal wires 281 is 4, and the quantity of the first metal wires 301 is 4, so the first total quantity is 24, and the second total quantity of the second metal wires 14 The system is 13, so the sum of the first total quantity and the second total quantity is 37, which is indeed an odd number. Based on this, the sum of the first total number of all the first metal lines 121, 221, 241, 261, 281, 301 and the second total number of all the second metal lines 141 is an odd number.

Of course, the metal oxide metal capacitor structure 10 shown in FIGS. 5 and 6 can also be designed as a three-dimensional stacked capacitor structure, which includes more than two electrode layers. Each electrode layer can have the same layout structure and number. Please refer to the detailed description recorded in the aforementioned Figure 4 for some details, and will not be repeated here.

In one embodiment, the present case is explained based on the actual layout structure of the metal oxide metal capacitor structure 10. Please also refer to FIG. 7. Under the same capacitance and the same quantity, by comparing the differences between the conventional technology and the present case , to show the effect that this case can achieve. As shown in Figure 7, taking the area when 150 metal oxide metal capacitor structures 40 and 10 are arranged as an example, the layout area of the conventional metal oxide metal capacitor structure 40 is 1073.43 μm ² . The metal oxide metal capacitor structure of this case 10 (As shown in Figure 3, the single first finger electrode structure and the shared second finger electrode structure can be regarded as a metal oxide metal capacitor structure) Using the shared second finger electrode structure, the entire layout area is reduced to 775.45 µm ² . Compared with the conventional metal oxide metal capacitor structure 40 , the area reduction rate of the metal oxide metal capacitor structure 10 in this case reaches 27.76%. Therefore, the layout occupied area can be effectively reduced, in line with the increasingly high concentration in the future. trend.

Furthermore, as shown in Table 1 below, when 50 metal oxide metal capacitor structures are laid out, the area reduction rate of the entire capacitor structure is 24.02%. When 200 metal oxide metal capacitor structures are laid out, the area reduction rate of the entire capacitor structure is 24.02%. The area reduction rate increased to 28.46%, and when the layout of 400 metal oxide metal capacitor structures was increased, the area reduction rate of the entire capacitor structure reached 29.01%. Therefore, as the number of metal oxide metal capacitor structures gradually increases, the area reduction rate of the entire capacitor structure will gradually increase and become higher and higher.

Table 1 Area difference comparison table quantity 50 100 150 200 250 300 350 400 Known capacitor structure area (µm ² ) 340.4 706.92 1073.43 1443.16 1806.46 2163.92 2539.49 2906 Capacitor structure area of this case (µm ² ) 258.63 512.41 775.45 1032.41 1292.28 1543.1 1809.1 2062 reduction rate 24.02% 27.51% 27.76% 28.46% 28.46% 28.69% 28.76% 29.01%

In summary, with the downward shrinkage of semiconductor dimensions and the increase in circuit density, this project proposes a metal oxide metal capacitor structure with a common second finger electrode structure, so that it can effectively maintain the same capacitance. Reduce the occupied integrated circuit area. Moreover, in this case, when two or more metal oxide metal capacitor structures are arranged, the shared second finger-shaped electrode structure helps to reduce the area, and the arrangement is also more flexible. Based on this, under the condition that the size and area of the chip (chip) is shrinking day by day, this case helps to reduce the use of area to obtain the same capacitance, so as to improve the area utilization rate.

The above-mentioned embodiments are only for illustrating the technical ideas and characteristics of this case. Their purpose is to enable those familiar with this technology to understand the contents of this case and implement them accordingly. However, they cannot be used to limit the patent scope of this case. That is, generally speaking, according to this case Equal changes or modifications made to the spirit disclosed should still be covered by the patent application scope of this case.

10: Metal oxide metal capacitor structure 12,12’: first finger electrode structure 121:First metal wire 122:First electrode 14,14’: Second finger electrode structure 141,141’,141”: second metal wire 142:Second electrode 16: First electrode layer 16’: Second electrode layer 18: First via hole 20: Second via hole 22: First finger electrode structure 221:First metal wire 222: First electrode 24: First finger electrode structure 241:First metal wire 242:First electrode 26: First finger electrode structure 261:First metal wire 262:First electrode 28: First finger electrode structure 281:First metal wire 282:First electrode 30: First finger electrode structure 301:First metal wire 302: First electrode 40,40’: Metal oxide metal capacitor structure 42,42’: first finger electrode structure 421,421’: First metal line 44,44’: Second finger electrode structure 441,441’: Second metal wire D:interval

Figure 1 is a schematic structural diagram of a conventional metal oxide metal capacitor structure. FIG. 2 is a schematic diagram of the combined structure of a conventional metal oxide metal capacitor structure. FIG. 3 is a schematic structural diagram of a metal oxide metal capacitor structure according to an embodiment of the present invention. FIG. 4 is a schematic structural diagram of a metal oxide metal capacitor structure according to another embodiment of the present invention. FIG. 5 is a schematic structural diagram of a metal oxide metal capacitor structure according to yet another embodiment of the present invention. FIG. 6 is a schematic structural diagram of a metal oxide metal capacitor structure according to another embodiment of the present invention. FIG. 7 is a schematic diagram of the layout structure of a conventional metal oxide metal capacitor structure and the metal oxide metal capacitor structure of the present invention.

10: Metal oxide metal capacitor structure 12: First finger electrode structure 121:First metal wire 122:First electrode 14: Second finger electrode structure 141: Second metal wire 142:Second electrode

Claims (3)

A metal oxide metal capacitor structure includes: a plurality of first finger electrode structures, each of the first finger electrode structures includes a plurality of first metal lines and a first electrode, and the first metal lines are along a first direction extending, the first electrode extends along a second direction and connects the first metal lines; and a second finger-shaped electrode structure includes a plurality of second metal lines and a second electrode, the second metal lines Extending along the first direction, the second electrode extends along the second direction and connects the second metal lines as a common electrode, and all the first metal lines and the second metal lines intersect with each other. arranged side by side between the first electrode and the second electrode, so that each first metal line is located between every two adjacent second metal lines; wherein a second total number of the second metal lines is greater than A first total number of all the first metal lines. The metal oxide metal capacitor structure as claimed in claim 1, wherein the sum of the first total number of all the first metal lines and the second total number of the second metal lines is an odd number. The metal oxide metal capacitor structure of claim 1, wherein the first finger electrode structures can be located on two opposite sides of the second finger electrode structure respectively, so as to share the second finger electrode structure.

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