TWI521677B - Capacitor in integrated circuit - Google Patents

Description

Capacitor of integrated circuit

The present invention relates to a structure of a capacitor, and more particularly to a structure of a capacitor of an integrated circuit.

With the advancement of semiconductor technology, integrated circuits have become an important component in electronic devices. Among them, the embedded capacitor in the integrated circuit is often an important component in the crystal circuit. However, it is necessary to dispose a capacitor having a sufficiently large capacitance value in the integrated circuit, which often consumes a large layout area of the integrated circuit, and therefore, how to construct a built-in circuit in consideration of the cost of the integrated circuit Embedded capacitors with large enough capacitance values have become a topic of interest to designers in this field.

The present invention provides a capacitor for an integrated circuit that utilizes a limited area to provide a larger capacitance value.

The capacitor of the integrated circuit provided by the present invention comprises a base layer, a first capacitor and a second capacitor, and the first capacitor is disposed in the base layer. The second capacitor is disposed on the first capacitor and at least partially covers the first capacitor. Wherein the first electrode of the first capacitor is coupled The first electrode of the second capacitor is coupled to the second electrode of the second capacitor.

Based on the above, the present invention performs a layout of a plurality of capacitors in the same vertical extending direction of the base layer by using different materials in the integrated circuit, and by connecting the capacitors in parallel, effectively in a fixed area. A capacitor with a large enough capacitance value can be provided. In this way, the embedded capacitor in the integrated circuit can not affect the excessive layout area and affect the cost.

The above described features and advantages of the present invention will be more apparent from the following description.

100, 300, 600‧‧ ‧ capacitance of integrated circuit

110, 510, 710‧‧ ‧ basal layer

120, 320, 620, 720‧‧‧ first capacitor

130, 330, 630, 730‧‧‧ second capacitor

E11, E21‧‧‧ first electrode

E12, E22‧‧‧ second electrode

T1~TN‧‧‧O crystal

S‧‧‧ source

D‧‧‧汲

G‧‧‧ gate

C1, C2‧‧‧ contact window

A-A’‧‧‧ segment

M11~M36‧‧‧ metal pattern

500‧‧‧Transistor Capacitance

520, 530‧‧ ‧ well area

541, 542‧‧‧Doped area

550‧‧‧ Polycrystalline layer

FIG. 1 is a schematic diagram showing the capacitance of an integrated circuit according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the capacitance of the integrated circuit.

3 is an equivalent circuit diagram of a capacitor of an integrated circuit according to another embodiment of the present invention.

4A and 4B are respectively a market diagram and a cross-sectional view showing the capacitance of the integrated circuit of the embodiment of the present invention.

FIG. 5 illustrates an embodiment of a transistor capacitor in accordance with an embodiment of the present invention.

6A and 6B are respectively a cross-sectional view and an equivalent circuit diagram of a capacitor of an integrated circuit according to still another embodiment of the present invention.

Please refer to FIG. 1. FIG. 1 is a schematic diagram showing the capacitance of an integrated circuit according to an embodiment of the present invention. The capacitor 100 of the integrated circuit includes a base layer 110, a first capacitor 120, and a second capacitor 130. The first capacitor 120 is disposed in the base layer 110, and the second capacitor 130 is disposed on the first capacitor 120. Moreover, the second capacitor 130 at least partially covers the first capacitor 120. In addition, please refer to FIG. 2 for an equivalent circuit diagram of the capacitance of the integrated circuit. The first capacitor 120 has a first electrode E11 and a second electrode E12, and the second capacitor 120 has a first electrode E21 and a second electrode E22. The first electrode E11 of the first capacitor 120 is coupled to the first electrode E21 of the second capacitor 120, and the second electrode E12 of the first capacitor 120 is coupled to the second electrode E22 of the second capacitor 120.

It should be noted that in FIG. 1, the second capacitor 130 may completely or partially cover the upper surface of the first capacitor 120. The main point is that the first capacitor 120 and the second capacitor 130 overlap each other on the base layer 110. Therefore, the layout of the second capacitor 130 is not performed through the area of the redundant integrated circuit, which can effectively save layout space. Moreover, the first capacitor 120 and the second capacitor 130 are coupled to each other in parallel, and therefore, the capacitance value provided by the capacitor 100 can be effectively increased.

In addition, in the embodiment, the first capacitor 120 is not limited to its material. The first capacitor 120 can be constructed using various materials that can form a capacitor in a semiconductor process, such as a transistor capacitor, a junction capacitor, or a metal-insulator-metal (MIM) capacitor.

Please refer to FIG. 3, which illustrates an integrated circuit according to another embodiment of the present invention. The equivalent circuit diagram of the capacitor. In this embodiment, the capacitor 300 of the integrated circuit includes a first capacitor 320 and a second capacitor 330 that are connected in parallel with each other. The first capacitor 320 is a transistor capacitor formed by the transistor T1. The source S and the drain D of the transistor T1 are coupled to each other to become the first electrode E11 of the first capacitor 320, and the gate G of the transistor T1 is the second electrode E12 of the first capacitor 320.

For the structure of the capacitor 300 of the integrated circuit of FIG. 3, please refer to FIG. 4A and FIG. 4B. FIG. 4A and FIG. 4B are respectively a market diagram and a cross-sectional view showing the capacitance of the integrated circuit of the embodiment of the present invention. In FIG. 4A, the second capacitor 330 is formed by staggering the metal patterns 331 and 332, wherein the metal pattern 331 forms the first electrode E21 of the second capacitor 330, and the metal pattern 332 forms the second electrode of the second capacitor 330. E22.

The first electrode E21 of the second capacitor 330 and the second electrode E22 of the second capacitor 330 are overlaid on the first capacitor 320. The first electrode E21 of the second capacitor 330 can be coupled to the first electrode of the first capacitor 320 through a plurality of contact windows C1, and the second electrode E22 of the second capacitor 330 can pass through a plurality of The contact window C2 is coupled to the second electrode of the first capacitor 320.

Fig. 4B is a cross-sectional view showing the capacitor 300 of the integrated circuit in accordance with the line segment A-A' of Fig. 4A. The second capacitor 330 includes a plurality of metal patterns M11 to M36 distributed on different metal layers. The metal patterns M11~M15 are distributed in the topmost metal layer, the metal patterns M21~M26 are distributed in the second metal layer, and the metal patterns M31~M36 are distributed in the bottommost metal layer. In this embodiment, adjacent metal patterns in the same metal layer are physically isolated from each other, and in the metal patterns M11 to M15, the metal patterns M11, M13, and M15 are coupled to each other to form a second The first electrode of the capacitor 330, and the metal patterns M12 and M14 are coupled to each other to form a second electrode of the second capacitor 330. In addition, in the metal patterns M21 to M26, the metal patterns M21, M23, and M15 are coupled to each other to form a second electrode of the second capacitor 330, and the metal patterns M22, M24, and M26 are coupled to each other to form a second capacitor 330. An electrode. Further, in the metal patterns M31 to M36, the metal patterns M31, M33, and M35 are coupled to each other to form a first electrode of the second capacitor 330, and the metal patterns M32, M34, and M36 are coupled to each other to form a second capacitor 330. Two electrodes. The second capacitor 330 is a metal-insulator-metal (MIM) capacitor.

Incidentally, a plurality of insulating layers are included in the plurality of metal layers in FIG. 4B to isolate the metal layers.

Of course, the construction of the first capacitor 320 of the embodiment of FIG. 3 using a transistor capacitor is merely an example and is not intended to limit the scope of the invention. The first capacitor 320 can also be formed using materials provided in other semiconductor processes.

Next, please refer to FIG. 5. FIG. 5 illustrates an embodiment of a transistor capacitor according to an embodiment of the present invention. The transistor capacitor 500 includes a base layer 510, a first well region 520, a second well region 530, doped regions 541 and 542, and a polysilicon layer 550. A first well region 520 is formed in the base layer 510, a second well region 530 is formed in the first well region 520, and doped regions 541, 542 are formed in two different regions of the second well region 530 to respectively form electricity The bungee and source of the crystal. A polysilicon layer 550 is covered in a region between the doping regions 541 and 542 to form a gate of the transistor.

The doped regions 541, 542 are connected to each other to become the first electrode E11 of the transistor capacitor 500, and the polysilicon layer 550 is the second electrode E12 of the transistor capacitor 500. in In this embodiment, the first electrode E11 and the second electrode E12 of the transistor capacitor 500 can be arbitrarily connected to different voltage levels.

In this embodiment, the base layer 510 may be a P-type base layer, the first well region 520 may be an N-type well region, the second well region 530 may be a P-type well region, and the doped regions 541 and 542 may be It is an N-type doped region.

Please note that the transistor capacitance of FIG. 5 is only an example, and the first capacitor of the present invention is not limited to being implemented by using such a transistor capacitor.

Referring to FIG. 6A and FIG. 6B, FIG. 6A and FIG. 6B are respectively a cross-sectional view and an equivalent circuit diagram of a capacitor of an integrated circuit according to still another embodiment of the present invention. In FIGS. 6A and 6B, the first capacitor 620 of the capacitor 600 of the integrated circuit can be implemented by a transistor capacitor composed of a plurality of parallel transistors T1 to TN. The gates of the transistors T1 T TN are connected to each other to form a second electrode of the first capacitor 620 , and the sources and the drains of the transistors T1 T TN are connected to each other to form a first electrode of the first capacitor 620 and pass through the first electrode. One electrode and the second electrode are connected in parallel with the second capacitor 630.

In summary, the present invention utilizes a plurality of mutually parallel capacitors in a stacked manner in the same vertical direction of the integrated circuit to effectively increase the capacitance of the capacitor in the integrated circuit in a limited area. In this way, the layout area occupied by the capacitance of the integrated circuit can be reduced, and the cost of the product can be effectively reduced.

100‧‧‧Capacitance of integrated circuit

110‧‧‧ basal layer

120‧‧‧first capacitor

130‧‧‧second capacitor

Claims (7)

A capacitor of an integrated circuit, comprising: a base layer; a first capacitor disposed in the base layer, wherein the first capacitor is a transistor capacitor, the transistor capacitor comprises a transistor, the transistor has a source a pole, a drain, and a gate, wherein a source and a drain of the transistor are coupled to each other and become a first electrode of the first capacitor, and a gate of the transistor is a second electrode of the first capacitor, the electricity The crystal includes: a first well region formed in the base layer; a second well region formed in the first well region; a first doping region formed in the second well region; a second a doping region formed in the second well region; and a polysilicon layer covering the first doping region and the second doping region, wherein the first doping region forms the transistor a source, the second doping region forms a drain of the transistor, the polysilicon layer forms a gate of the transistor; and a second capacitor is disposed on the first capacitor and at least partially covers the first capacitor The first electrode of the first capacitor is coupled to the first electrode of the second capacitor And a second electrode of the first capacitor coupled to the second electrode of the second capacitor. The capacitor of the integrated circuit according to claim 1, wherein the base layer is a P-type base layer, the first well region is an N-type well region, and the second well region is a P-type In the well region, the first and the second doping regions are N-type doping regions. The capacitor of the integrated circuit of claim 1, wherein when the number of the at least one transistor included in the transistor capacitor is plural, each of the transistors has a source, a drain, and a gate. The sources and the drains of the transistors are coupled to each other to form a first electrode of the first capacitor, and the gates of the transistors are coupled to each other to form a second electrode of the first capacitor. The capacitor of the integrated circuit of claim 1, wherein the second capacitor is a metal-insulator-metal capacitor. The capacitor of the integrated circuit of claim 4, wherein the second capacitor comprises: a plurality of metal layers, each of the metal layers having a plurality of metal patterns, and a plurality of first partial metal patterns of the metal patterns The first electrodes are coupled to each other to form the second capacitor, and the plurality of second partial metal patterns of the metal pattern are coupled to each other to form a first electrode of the second capacitor. The capacitor of the integrated circuit of claim 5, wherein the second capacitor further comprises: a plurality of insulating layers, each of the insulating layers being disposed between adjacent two metal layers of the metal layers. The capacitor of the integrated circuit of claim 5, wherein adjacent metal patterns in each of the metal layers are physically isolated from each other.