CN114582860B - A multi-capacitance matching MOM capacitor - Google Patents

Abstract

The invention provides a multi-capacitance matching type MOM capacitor, comprising: a substrate; a capacitor body located above the substrate, which comprises: multi-layer metallization layers and multi-layer dielectric layers, each of which has a dielectric layer between the two metallization layers , each metallization layer has a plurality of first electrode strips and second electrode strips arranged at intervals and parallel to each other, and an isolation dielectric is filled between the adjacent first electrode strips and the second electrode strips; the common T plate, All the first electrode strips are electrically connected to the common T plate; a plurality of B plates are arranged in parallel and opposite to the common T plate, and the capacitor body is divided into a plurality of matching capacitor units. The electrode strips are connected to the corresponding B pole plates; the redundant pole plates are arranged on the outer side of the B pole plates at the edge, and are arranged in parallel and opposite to the common T pole plates; the redundant capacitors are located on the base and outside the capacitor body, One end of the redundant capacitor is connected to the common T plate, and the other end is connected to the redundant plate.

Description

A multi-capacitance matching MOM capacitor

technical field

The invention relates to the technical field of integrated circuits, in particular to a multi-capacitor matching MOM capacitor.

Background technique

Capacitors are an important component of integrated circuits (IC for short), and are widely used in memory, microwave, radio frequency, smart cards and filtering chips.

With the continuous advancement of semiconductor integrated circuit manufacturing technology, the performance of semiconductor devices is also continuously improved. In the process of improving the integration of integrated circuits, how to obtain high-density capacitors in a limited area has become an important issue.

Existing capacitors generally include: junction capacitors, gate capacitors, metal-metal (Intra-metal) capacitors, and the like. Among them, in the case of high capacitance density, the linearity and quality factor of junction capacitors and gate capacitors are poor, and the breakdown voltage is low, and the applicability is not strong; while the linear characteristics of metal-metal (Intra-metal) capacitors are far It is better than other types of capacitors, so it has better accuracy and can better meet the needs of high capacitance density occasions. The above-mentioned metal-metal (Intra-metal) capacitors include MIM (metal-insulator-metal, metal-insulator-metal) capacitors and MOM (metal-oxide-metal, metal-oxide-metal) capacitors.

In many analog circuits such as high-precision ADC (Analog to Digital Converter, analog-to-digital converter), the matching of capacitors directly affects the accuracy of the circuit. As shown in Figure 1, the four capacitors, the T terminals are connected together. As sensitive nodes, B1~B4 may be connected to different signals respectively. The four capacitors require the higher the matching accuracy, the better.

Therefore, how to improve the matching accuracy of multiple capacitors and reduce the chip size of the multi-capacitor matching MOM capacitor is an urgent problem for those skilled in the art to solve.

SUMMARY OF THE INVENTION

The invention discloses a multi-capacitor matching MOM capacitor, which can improve the matching accuracy of the multiple capacitors and reduce the chip size of the multi-capacitor matching MOM capacitor.

In order to solve the above-mentioned technical problems, the present invention provides a multi-capacitance matching MOM capacitor, comprising:

base;

A capacitor body, the capacitor body is located above the substrate, and the capacitor body includes: multiple metallization layers and multiple dielectric layers, and there is a dielectric layer between every two metallization layers, and each The metallization layer has a plurality of first electrode strips and second electrode strips arranged at intervals and parallel to each other, and an isolation dielectric is filled between the adjacent first electrode strips and the second electrode strips;

Common T plate, all the first electrode strips are electrically connected to the common T plate;

A plurality of B plates are arranged in parallel and opposite to the common T plate, and the capacitor body is divided into a plurality of matching capacitor units, and the second electrode strip of each matching capacitor unit is connected to the corresponding the B plate;

Redundant pole plates, arranged on the outside of the B pole plates on the edge, and arranged in parallel with the common T pole plates;

A redundant capacitor, the redundant capacitor is located on the base and outside the capacitor body, one end of the redundant capacitor is connected to the common T plate, and the other end is connected to the redundant plate .

In an optional solution, the common T-pole plate includes two opposite sides, and a plurality of the B-pole plates are arranged on the same side of the common T-pole plate, or a plurality of the B-pole plates are separately arranged on the common T-pole plate. Both sides of the T plate.

In an optional solution, a plurality of the B pole plates are arranged on both sides of the common T pole plate, and the B pole plates located on one side of the common T pole plate are connected to the common T pole plate through a conductive structure. The B pole plates on the other side of the pole plates are electrically connected, so that the outlet ports of the B pole plates are all located on one side of the common T pole plate.

In an optional solution, the redundant capacitor includes multiple metallization layers and multiple dielectric layers, and there is a dielectric layer between every two metallization layers, and each metallization layer has a plurality of dielectric layers. The first redundant electrode strips and the second redundant electrode strips are arranged at intervals and are parallel to each other, and an isolation dielectric is filled between the adjacent first redundant electrode strips and the second redundant electrode strips, wherein all The first redundant electrode strips are connected to the common T plate, and all the second redundant electrode strips are connected to the redundant electrodes.

In an optional solution, each of the metallization layers of the redundant capacitor corresponds to each of the metallization layers of the capacitor body, and each of the dielectric layers of the redundant capacitor corresponds to the Each of the dielectric layers of the capacitor body is in one-to-one correspondence.

In an optional solution, the length of the first redundant electrode strip is equal to the length of the second redundant electrode strip, and is equal to the length of the first electrode strip and the length of the second electrode strip.

In an optional solution, a plurality of the B-pole plates are electrically connected to external signals through their respective conductive structures, or a set number of the B-pole plates are electrically connected first and then electrically connected to the external signals.

In an optional solution, a plurality of the redundant pole plates are connected to the reference ground through respective conductive structures, or a set number of the redundant pole plates are firstly connected to the reference ground and then connected to the reference ground.

In an optional solution, the first electrode strips are arranged equidistantly from two adjacent second electrode strips.

In an optional solution, in the vertical direction, the second electrode strips are provided above and below the first electrode strips.

The beneficial effects of the present invention are:

By sharing the common T plate and connecting redundant capacitors, the invention improves the matching accuracy of multiple capacitors and facilitates the use of analog-to-digital converters (ADC) and other circuits that require high matching accuracy. It not only increases the effective capacitance value, but also reduces the use of redundant capacitors and reduces the chip size.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of the exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which the same reference numerals generally refer to the same parts .

FIG. 1 shows a schematic diagram of a multi-capacitor matched MOM capacitor in the prior art.

FIG. 2a shows a schematic structural diagram of a multi-capacitor matched MOM capacitor according to an embodiment of the present invention.

FIG. 2b is the circuit diagram of FIG. 2a.

FIG. 3a is a cross-sectional view of the multi-capacitor matched MOM capacitor at A in FIG. 2a.

FIG. 3b is a cross-sectional view of the multi-capacitor matched MOM capacitor at B in FIG. 2a.

FIG. 4a shows a schematic structural diagram of a multi-capacitor matched MOM capacitor according to another embodiment of the present invention.

FIG. 4b is the circuit diagram of FIG. 4a.

FIG. 5a shows a schematic structural diagram of a multi-capacitor matched MOM capacitor according to still another embodiment of the present invention.

FIG. 5b is the circuit diagram of FIG. 5a.

Reference number:

1-common T plate; 11-first electrode strip; 2-B plate; 21-second electrode strip; 301-first redundant electrode strip; 302-second redundant electrode strip; 3-redundant electrode plate.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and accompanying drawings. However, it should be noted that the concept of the technical solution of the present invention can be implemented in various forms, and is not limited to the specific implementation described here. example. The accompanying drawings are all in a very simplified form and in an inaccurate scale, and are only used to facilitate and clearly assist the purpose of explaining the embodiments of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the/the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the terms "compose" and/or "include", when used in this specification, identify the presence of stated features, integers, steps, operations, elements and/or components, but do not exclude one or more other The presence or addition of features, integers, steps, operations, elements, parts and/or groups. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

If a method herein includes a series of steps, the order of the steps presented herein is not necessarily the only order in which the steps may be performed, and some of the steps may be omitted and/or some other steps not described herein may be added to this method. If the components in a certain drawing are the same as the components in other drawings, although these components can be easily identified in all the drawings, in order to make the description of the drawings clearer, this specification will not refer to all the same components. Numbers are attached to each figure.

An embodiment of the present invention provides a multi-capacitor matched MOM capacitor, the multi-capacitor matched MOM capacitor includes:

base;

A capacitor body, the capacitor body is located above the substrate, and the capacitor body includes: multiple metallization layers and multiple dielectric layers, and there is a dielectric layer between every two metallization layers, and each The metallization layer has a plurality of first electrode strips and second electrode strips arranged at intervals and parallel to each other, and an isolation dielectric is filled between the adjacent first electrode strips and the second electrode strips;

A common T plate, all the first electrode strips are electrically connected to the common T plate; a plurality of B plates are arranged in parallel and opposite to the common T plate, and the capacitor body is divided into multiple There are matching capacitor units, and the second electrode strip of each matching capacitor unit is connected to the corresponding B plate; the B plate is used to connect electrical signals.

The redundant pole plate is arranged on the outer side of the B pole plate at the edge, and is arranged in parallel and opposite to the common T pole plate; the redundant pole plate is used to connect the reference ground.

A redundant capacitor, the redundant capacitor is located on the base and outside the capacitor body, one end of the redundant capacitor is connected to the common T plate, and the other end is connected to the redundant plate .

The common T-pole plate includes two opposite sides, and a plurality of the B-pole plates may all be arranged on the same side of the common T-pole plate, or a plurality of B-pole plates may be arranged on both sides of the common T-pole plate.

In this embodiment, the redundant capacitor includes multiple metallization layers and multiple dielectric layers, there is a dielectric layer between every two metallization layers, and each metallization layer has multiple The first redundant electrode strips and the second redundant electrode strips are arranged at intervals and are parallel to each other, and an isolation dielectric is filled between the adjacent first redundant electrode strips and the second redundant electrode strips, wherein all The first redundant electrode strips are connected to the common T-pole plate, and all the second redundant electrode strips are connected to the redundant pole plate. In an alternative solution, each metallization layer of the redundant capacitor corresponds to each metallization layer of the capacitor body one-to-one, and each of the dielectric layers of the redundant capacitor corresponds to the capacitor Each of the dielectric layers of the main body corresponds to each other. During fabrication, the redundant electrode strips of the redundant capacitor and the electrode strips of the capacitor body are fabricated in a synchronous process.

The material of the first redundant electrode strip and the second redundant electrode strip is metal. The number of the first redundant electrode strip and the second redundant electrode strip located on the same metallization layer can be one or more, and when there are multiple, the first redundant electrode strip and the second redundant electrode The bars are spaced in parallel.

In different embodiments, a plurality of the B-pole plates are electrically connected to external signals through respective conductive structures, or a set number of the B-pole plates are electrically connected first, and then electrically connected to the external signals. In this embodiment, different B plates are connected to different signals. In other embodiments, there are eight independent matching capacitor units, and the ratio of the eight matching capacitor units is 1:1:1:1:1: 1:1:1, when it needs to be combined into four capacitors, and the ratio of the four capacitors is 1:1:2:4, connect two of the B-polarizers through a conductive structure, and four of the B-polarizers are electrically connected. The plates are electrically connected by conductive structures. Capacitors can be combined through this connection method to adjust the ratio between capacitors.

In one example, a plurality of the redundant pole plates are connected to the reference ground through respective conductive structures. In another example, a set number of the redundant pole plates are first electrically connected, and then connected to the reference ground.

In this embodiment, in the vertical direction, the upper and lower sides of the first electrode strips are both the second electrode strips. That is, the top, bottom, left, and right of the first electrode strip are all second electrode strips, and the top, bottom, left, and right of the second electrode strip are both first electrode strips.

In this embodiment, the first electrode strips and the second electrode strips are elongated. In a preferred solution, the lengths of the first electrode strip and the second electrode strip are equal. The lengths of the first redundant electrode strips are equal to the lengths of the second redundant electrode strips, and are equal to the lengths of the first electrode strips and the second electrode strips. The first electrode strips are equidistant from two adjacent second electrode strips.

By sharing the common T plate and connecting redundant capacitors, the invention improves the matching accuracy of multiple capacitors and facilitates the use of analog-to-digital converters (ADC) and other circuits that require high matching accuracy. It not only increases the effective capacitance value, but also reduces the use of redundant capacitors and reduces the chip size.

Multiple capacitors share a common T plate, and the B plate is connected to different signals. The capacitance from the common T plate to the B plate is an effective capacitance, including the parasitic capacitance between the common T plate and the B plate. The common T plate is a sensitive node, and the B plate is relatively insensitive. Excluding processing errors, the present invention can ensure that the effective capacitance values of multiple capacitors are completely equal.

Example 1

This embodiment provides a specific structure of a multi-capacitance matching MOM capacitor. Please refer to FIGS. 2a and 2b. FIG. 2a is a top view, which is an internal structure of one of the metallization layers.

The common T plate 1 extends along the left and right directions of the figure, and has a plurality of first electrode strips 11. In this embodiment, there are ten first electrode strips 11. The first electrode strips 11 include opposite first ends and a third At both ends, a plurality of the first electrode strips 11 are arranged in parallel along the extending direction of the common T plate 1 (the left-right direction in the figure), and the first end of each of the first electrode strips 11 ( The upper end in the figure) is connected to the common T-pole plate 1; at least two B-pole plates 2 (four B-pole plates 2 are shown in the figure), the B-pole plates 2 and the first electrode strips 11 The second ends of the electrodes are oppositely arranged (the first electrode strips 11 and the B plate are not in contact); a plurality of second electrode strips 21, the second electrode strips 21 include opposite first and second ends, so The second electrode strips 21 are arranged in parallel along the extending direction of the B plate 2 (the left-right direction in the figure), and the first end (lower end in the figure) of each second electrode strip 21 is connected to the On the B plate 2, the first electrode strips 11 and the second electrode strips 21 are arranged parallel to each other and spaced apart; a dielectric layer (not shown in the figure), the dielectric layer is filled in the Between an electrode strip and the second electrode strip; the redundant pole plate 3 is arranged on the outer side of the B pole plate 2 at the edge, and is arranged in parallel and opposite to the common T pole plate 1; the redundant capacitor, the A redundant capacitor is located on the base and outside the capacitor body. One end of the redundant capacitor is connected to the common T plate 1 , and the other end is connected to the redundant plate 3 .

In this embodiment, the redundant capacitor includes multiple metallization layers and multiple dielectric layers, and there is a dielectric layer between every two metallization layers, and each metallization layer has a plurality of first spaced and parallel to each other. The redundant electrode strips 301 and the second redundant electrode strips 302, and the adjacent first redundant electrode strips 301 and the second redundant electrode strips 302 are filled with an isolation dielectric, wherein all the first redundant electrode strips 301 Connected to the common T pole plate 1 , all the second redundant electrode strips 302 are connected to the redundant pole plate 3 .

In this embodiment, the common T-pole plate includes two opposite sides, and the four B-pole plates are all disposed on the same side (lower side) of the common T-pole plate 1 . In this embodiment, the first electrode strips 11 and the two adjacent second electrode strips 21 are arranged at equal distances, S1=S2, and each B plate is connected with two second electrode strips (with one layer of metal layer for example). The first electrode strips and the second electrode strips are elongated, and the lengths of the first electrode strips 11 and the second electrode strips 21 are equal.

Referring to FIG. 3 a and FIG. 3 b , in this embodiment, the multi-capacitor matching MOM capacitor is formed on a semiconductor substrate, and the multi-capacitor matching MOM capacitor is manufactured by a semiconductor process. The first electrode strips 11 and the second electrode strips 21 are embedded in the dielectric layer, and the first electrode strips 11 of the adjacent metallization layers are electrically connected by plugs penetrating the dielectric layers; all the adjacent metallization layers are electrically connected. The second electrode strips 21 are electrically connected by plugs penetrating the dielectric layer. The figure shows four metal layers (M1~M4), and V1, V2, and V3 are plugs passing through the dielectric layer.

Example 2

This embodiment provides a specific structure of a multi-capacitance matching MOM capacitor. The difference between Embodiment 2 and Embodiment 1 is that the distribution mode of the B plate 2 is different.

4a and 4b, the multi-capacitor matching MOM capacitor includes eight B-pole plates 2, which are symmetrically arranged on both sides of the common T-pole plate 1, and four B-pole plates 2 are arranged on each side. It includes four redundant capacitors, which are arranged on the outermost side. The structure of the redundant capacitors is the same as that of the first embodiment. In this embodiment, the common T-pole plate 1 is placed in the middle, and the common T-pole plate 1 is enclosed inside, which can better isolate the sensitive nodes.

Example 3

This embodiment provides a specific structure of a multi-capacitance matching MOM capacitor. The difference between Embodiment 3 and Embodiment 2 is that the electrical connection between the B plate and the external signal is different.

5a and 5b, a plurality of the B pole plates are arranged on both sides of the common T pole plate, and the B pole plates located on one side of the common T pole plate are connected with each other through a conductive structure. The B pole plates on the other side of the common T pole plate are electrically connected, so that the outlet ports of the B pole plates are all located on one side of the common T pole plate. A plurality of the redundant pole plates are arranged on both sides of the common T pole plate and the redundant pole plates located on one side of the common T pole plate are connected to the other side of the common T pole plate through a conductive structure. The redundant pole plates on the side are electrically connected, so that the outlet ports of the redundant pole plates are all located on one side of the common T pole plate.

In this embodiment, the two matching capacitor units are conductively interconnected with their respective B electrode plates through a conductive structure, so that the two matching capacitor units are powered through one B electrode plate. The two redundant capacitors are conductively interconnected with their respective redundant pole plates through a conductive structure, so that the two redundant capacitors are connected to the reference ground through one redundant pole plate.

As an optional method, the conductive structure of this embodiment is set by removing a layer of metal connection of the original T plate (the area under the slanted shadow in Fig. 5a ). Referring to Fig. 3a, for example, the metal connection of the T plate is Layer M2 or M4, the connection line of the B plate of the lower matching capacitor unit in Figure 5a passes through the T plate through the region where the metal layer is removed from the T plate, and is electrically connected to the upper B plate in Figure 5a. In this way, the outlet port only needs to be on one side, and the cable outlet is on the upper side in the figure.

It should be noted that each embodiment in this specification is described in a related manner, and the same and similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. .

The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes and modifications made by those of ordinary skill in the field of the present invention based on the above disclosure all belong to the protection scope of the claims.

Claims (9)

1. a multi-capacitance matching type MOM capacitor, is characterized in that, comprises: base; A capacitor body, the capacitor body is located above the substrate, and the capacitor body includes: multiple metallization layers and multiple dielectric layers, and there is a dielectric layer between every two metallization layers, and each The metallization layer has a plurality of first electrode strips and second electrode strips arranged at intervals and parallel to each other, and an isolation dielectric is filled between the adjacent first electrode strips and the second electrode strips; adjacent the first electrode strip and the second electrode strip in the metallization layer are stacked in the vertical direction; Common T plate, all the first electrode strips are electrically connected to the common T plate; A plurality of B plates are arranged in parallel and opposite to the common T plate, and the capacitor body is divided into a plurality of matching capacitor units, and the second electrode strip of each matching capacitor unit is connected to the corresponding the B plate; Redundant pole plates, arranged on the outside of the B pole plates on the edge, and arranged in parallel with the common T pole plates; A redundant capacitor, the redundant capacitor is located on the base and outside the capacitor body, one end of the redundant capacitor is connected to the common T plate, and the other end is connected to the redundant plate ; The common T-pole plate includes two opposite sides, and a plurality of the B-pole plates are arranged on both sides of the common T-pole plate. 2. The multi-capacitance matching MOM capacitor of claim 1, wherein a plurality of the B plates are arranged on both sides of the common T plate, and are located on one side of the common T plate The described B pole plate is electrically connected with the described B pole plate on the other side of the common T pole plate through a conductive structure, so that the outlet ports of the B pole plate are all located on one side of the common T pole plate . 3. The multi-capacitor matching MOM capacitor according to claim 1, wherein the redundant capacitor comprises a multi-layer metallization layer and a multi-layer dielectric layer, and there is a In the dielectric layer, each of the metallization layers has a plurality of first redundant electrode strips and second redundant electrode strips arranged at intervals and parallel to each other, and the adjacent first redundant electrode strips and the An isolation dielectric is filled between the second redundant electrode strips, wherein all the first redundant electrode strips are connected to the common T plate, and all the second redundant electrode strips are connected to the redundant electrodes plate. 4 . The multi-capacitor matching MOM capacitor of claim 3 , wherein each of the metallization layers of the redundant capacitor is in one-to-one correspondence with each of the metallization layers of the capacitor body, 5 . Each of the dielectric layers of the redundant capacitor is in one-to-one correspondence with each of the dielectric layers of the capacitor body. 5 . The multi-capacitor matching MOM capacitor of claim 3 , wherein the length of the first redundant electrode strip is equal to the length of the second redundant electrode strip, and is equal to the length of the first electrode strip. 6 . , the length of the second electrode strips are equal. 6. The multi-capacitance matching type MOM capacitor of claim 1, wherein a plurality of the B-pole plates are electrically connected to external signals through respective conductive structures, or the B-pole plates of a set number conduct electricity first connected, and then electrically connected to external signals. 7. The multi-capacitance matching MOM capacitor of claim 1, wherein a plurality of the redundant pole plates are connected to the reference ground through respective conductive structures, or the redundant pole plates of a set number are first connected to the reference ground. Conductive connection, and then connect to the reference ground. 8 . The multi-capacitance matching MOM capacitor according to claim 1 , wherein the first electrode strip and the adjacent two second electrode strips are arranged at equal distances. 9 . 9 . The multi-capacitance matching MOM capacitor of claim 1 , wherein in the vertical direction, the second electrode strips are provided above and below the first electrode strips. 10 .

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