Capacitor structure and forming method thereof

Abstract

A capacitor structure and a forming method thereof, the capacitor structure comprising: at least one layer of electrode plate structure, the electrode plate structure comprising: a plurality of circles of first electrode plates (301) and a plurality of circles of second electrode plates (302) alternately arranged along a first direction, the plurality of circles of first electrode plates (301) and the plurality of circles of second electrode plates (302) being mutually discrete, the first electrode plate (301) comprises a plurality of first branch parts (C1) which are connected and closed, the first branch parts (C1) are petal-shaped, the second electrode plate (302) comprises a plurality of second branch parts (C2) which are connected and closed, the second branch parts (C2) are petal-shaped, and the second branch parts (C2) are petal-shaped. The curvature radiuses of the plurality of first electrode plates (301) and the curvature radiuses of the plurality of second electrode plates (302) are gradually increased from the inner ring to the outer ring; and the dielectric structures are positioned between the adjacent layers of the first electrode plate and the second electrode plate of the same layer of electrode plate structure. The capacitance density of the capacitor structure is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a capacitor structure and a method for forming the same. Background Art

[0002] Capacitors in passive devices are indispensable in most logic, radio frequency, and storage integrated circuits. Reducing the area occupied by capacitors is also an effort to improve the integration of integrated circuits and increase the number of dies. Nowadays, metal-insulator-metal capacitors (MIM) and metal-oxide-metal capacitors (MOM) are mostly used in circuit design. Among them, compared with metal-insulator-metal capacitors, metal-oxide-metal capacitors have good capacitance matching, process compatibility and lower cost, so they are widely used in analog circuits and digital integrated circuits.

[0003] High-performance metal-oxide-metal capacitors are often evaluated from the dimensions of important parameters such as capacitance density, leakage current and capacitance voltage coefficient. Among them, with the development trend of continuous miniaturization of integrated circuit size, it is urgent to improve the capacitance density. In order to obtain a sufficiently large capacitance, the commonly used methods and their limitations are: 1. Thinning the thickness of the insulating medium, but it is limited by the material and electrical requirements, such as breakdown voltage; 2. Using insulating dielectric materials with high dielectric constants, but the cost increases and the process is limited; 3. Increasing the specific surface area of ​​the capacitor, but simply increasing the specific surface area will waste area, reduce the number of dies, and increase costs.

[0004] Therefore, it is necessary to optimize the metal-oxide-metal capacitor in terms of structural design to improve the capacitance density. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a capacitor structure and a method for forming the same, so as to improve the capacitance density.

[0006] To solve the above technical problems, an embodiment of the present invention provides a capacitor structure, including: at least one layer of electrode plate structure, the electrode plate structure including: several circles of first electrode plates and several circles of second electrode plates alternately arranged along a first direction, the several circles of first electrode plates and the several circles of second electrode plates are separate from each other, the first electrode plate includes several connected and closed first divisions, the shape of the first division includes a "petal" type, the second electrode plate includes several connected and closed second divisions, the shape of the second division includes a "petal" type, the curvature radius of several first electrode plates and the curvature radius of several second electrode plates gradually increase from the inner circle to the outer circle; a dielectric structure, located between the first electrode plate and the second electrode plate of adjacent layers of the same layer of electrode plate structure.

[0007] Optionally, the first electrode plate and the second electrode plate have a first width, adjacent first electrode plates and second electrode plates have a first spacing, and a ratio of the first width to the first spacing is in a range of 0.5-2.

[0008] Optionally, the number of the first divisions is the same as the number of the second divisions; the number of the first divisions and the number of the second divisions include three, four, five or six.

[0009] Optionally, the electrode plate structure is multi-layered, the multi-layer electrode plate structure is stacked in the second direction, and the electrode plate structures in adjacent layers are electrically connected, and the second direction is perpendicular to the first direction.

[0010] Optionally, the capacitor structure further includes: a connection structure located between the electrode plate structures in adjacent layers, and the electrode plate structures in adjacent layers are electrically connected via the connection structure.

[0011] Optionally, the connection structure includes: a first electrical connection layer and a second electrical connection layer, the first electrical connection layer electrically connects the first electrode plates of adjacent layers, and the second electrical connection layer electrically connects the second electrode plates of adjacent layers.

[0012] Optionally, the dielectric structure is also located between the first electrical connection layer and the second electrical connection layer which are adjacent to each other in the same layer.

[0013] Optionally, the width of the first electrical connection layer is less than or equal to the width of the first electrode plate; and the width of the second electrical connection layer is less than or equal to the width of the second electrode plate.

[0014] Optionally, the material of the first electrical connection layer is the same as that of the first electrode plate; the material of the second electrical connection layer is the same as that of the second electrode plate; and the material of the first electrode plate is the same as that of the second electrode plate.

[0015] Correspondingly, an embodiment of the present invention also provides a method for forming the capacitor structure, comprising: providing a substrate; forming a dielectric structure and at least one layer of electrode plate structure on the substrate, the electrode plate structure comprising: a plurality of circles of first electrode plates and a plurality of circles of second electrode plates alternately arranged along a first direction, the plurality of circles of first electrode plates and the plurality of circles of second electrode plates being separate from each other, the first electrode plate comprising a plurality of connected and closed first divisions, the projection shape of the first divisions on the substrate comprising a "petal" type, the second electrode plate comprising a plurality of connected and closed second divisions, the projection shape of the second divisions on the substrate comprising a "petal" type, the curvature radii of the plurality of first electrode plates and the curvature radii of the plurality of second electrode plates gradually increasing from the inner circle to the outer circle, and the dielectric structure being located between the first electrode plates and the second electrode plates of adjacent layers of the same layer of the electrode plate structure.

[0016] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0017] In the capacitor structure of the technical solution of the present invention, the "petal"-shaped first and second divisions have a larger specific surface area, thereby increasing the capacitance density of the capacitor formed, while occupying a smaller layout area.

[0018] Furthermore, the capacitor structure also includes a connecting structure, which can connect the capacitor units formed by adjacent first electrode plates and second electrode plates among the plurality of first electrode plates and the plurality of second electrode plates, and then enable the plurality of capacitor units to be connected in parallel through the electrical connection between the first conductive structure and the second conductive structure, which can greatly improve the capacitor density under a limited footprint; in addition, the connecting structure is electrically connected to the electrode plate structure, and a capacitor can also be formed between the plurality of circles of the first electrical connection layer and the plurality of circles of the second electrical connection layer, so that the overall capacitance value of the capacitor structure is increased, further improving the capacitor density of the capacitor structure.

[0019] The method for forming a capacitor structure of the technical solution of the present invention has a simple process and is easy to implement, and can improve production efficiency and yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a capacitor structure in one embodiment;

[0021] Figure 2 is a schematic structural diagram of a capacitor structure in one embodiment;

[0022] Figures 3 to 8 Schematic diagram of the capacitor structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] As described in the background art, improving the capacitance density of metal-oxide-metal capacitors is a problem that needs to be solved continuously. The following will be described in detail with reference to the accompanying drawings.

[0024] Figure 1 is a structural schematic diagram of a capacitor structure in an embodiment.

[0025] Please refer to Figure 1 The capacitor structure is a finger-shaped capacitor structure, including: a plurality of first finger electrodes 101 and a plurality of second finger electrodes 102 alternately arranged along a first direction; a dielectric structure 110, wherein the plurality of first finger electrodes 101 and the second finger electrodes 102 are located in the dielectric structure; a first conductive structure 103 electrically connected to the plurality of first finger electrodes 101, wherein the first conductive structure 103 is parallel to the first direction, and a plurality of second finger electrodes 102 and the first conductive structure 103 have a spacing therebetween; a second conductive structure 104 electrically connected to the plurality of second finger electrodes 102, wherein the second conductive structure 104 is parallel to the first direction, and a plurality of first finger electrodes 101 and the second conductive structure 104 have a spacing therebetween.

[0026] The plurality of first interdigitated finger electrodes 101 and the plurality of second interdigitated finger electrodes 102 of the capacitor structure are alternately arranged along a first direction, occupying a larger area in the first direction; in addition, a certain distance needs to be maintained between the second interdigitated finger electrodes 102 and the first conductive structure 103, and a certain distance needs to be maintained between the first interdigitated finger electrodes 101 and the second conductive structure 104, so as to ensure that the parasitic capacitance generated between the second interdigitated finger electrodes 102 and the first conductive structure 103 is not too large, and to ensure that the parasitic capacitance generated between the first interdigitated finger electrodes 101 and the second conductive structure 104 is not too large, and therefore, a larger area is also required in the second direction perpendicular to the first direction.

[0027] In summary, a single capacitor structure occupies a large layout area and has a low capacitance density. In addition, in order to meet the capacitance density requirements, multiple capacitors need to be integrated, which also occupies a large layout area.

[0028] Figure 2 is a structural schematic diagram of a capacitor structure in an embodiment.

[0029] Please refer to Figure 2 The capacitor structure is a circular capacitor structure, including: a plurality of circles of first electrode plates 201 and a plurality of circles of second electrode plates 202 arranged alternately, the projection pattern of the first electrode plates 201 is a circle, and the projection pattern of the second electrode plates 202 is a circle; a dielectric structure 210, wherein the plurality of first electrode plates 201 and the second electrode plates 202 are located in the dielectric structure.

[0030] A single capacitor occupies a large layout area, and the layout of multiple capacitors arranged in an integrated manner inevitably occupies a large layout area.

[0031] In order to solve the above problems, the technical solution of the present invention provides a capacitor structure and a method for forming the same, wherein the electrode plate structure comprises: several circles of first electrode plates and several circles of second electrode plates alternately arranged along a first direction, wherein the first electrode plate comprises several connected and closed first divisions, and the projection shape of the first division comprises a "petal" type, and the second electrode plate comprises several connected and closed second divisions, and the projection shape of the second division comprises a "petal" type, and the curvature radius of several first electrode plates and the curvature radius of several second electrode plates gradually increase from the inner circle to the outer circle, and the "petal"-shaped first division and second division have a larger specific surface area, which improves the capacitance density. Under the same specific surface area, the occupied layout area is smaller.

[0032] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] Figures 3 to 8 Schematic diagram of the capacitor structure in an embodiment of the present invention.

[0034] Please refer to Figures 3 to 7 , Figure 3 This is a three-dimensional schematic diagram of the capacitor structure with the connection structure omitted. Figure 4 for Figure 3 Schematic diagram of the structure along the section line AA'. Figure 5 for Figure 3 and Figure 4 The top view of the connection structure is omitted. Figure 6 is a top view schematic diagram of a single-layer first electrode plate, Figure 7 is a schematic top view of a single-layer second electrode plate, and the capacitor structure may include:

[0035] At least one layer of electrode plate structure, the electrode plate structure may include: a plurality of circles of first electrode plates 301 and a plurality of circles of second electrode plates 302 alternately arranged along a first direction X, the plurality of circles of first electrode plates 301 and the plurality of circles of second electrode plates 302 are separate from each other, the first electrode plate 301 includes a plurality of connected and closed first subdivisions C1, the shape of the first subdivision C1 may include a "petal" type, the second electrode plate 302 includes a plurality of connected and closed second subdivisions C2, the shape of the second subdivision C2 may include a "petal" type, and the curvature radii of the plurality of first electrode plates 301 and the curvature radii of the plurality of second electrode plates 302 gradually increase from the inner circle to the outer circle;

[0036] The dielectric structure is located between the first electrode plate 301 and the second electrode plate 302 in adjacent layers of the same electrode plate structure.

[0037] In this embodiment, the shapes of the first sub-portion C1 and the second sub-portion C2 are projection shapes of the first sub-portion C1 and the second sub-portion C2 in the second direction Y direction.

[0038] In this embodiment, the first electrode plate 301 , the second electrode plate 302 , and the dielectric structure between the first electrode plate 301 and the second electrode plate 302 may form a MIM capacitor.

[0039] In this embodiment, the "petals" may specifically be semicircular or semi-elliptical, and this application does not make any specific limitation on this.

[0040] In this embodiment, the first electrode plate of the electrode plate structure of the capacitor is composed of a number of connected and closed "petal"-shaped first divisions, and the second electrode plate of the electrode plate structure is composed of a number of connected and closed "petal"-shaped second divisions. The "petal"-shaped first division C1 and the second division C2 have a larger specific surface area, which can improve the capacitance density of the formed capacitor, and at the same time can also make the occupied layout area smaller, thereby improving the layout utilization rate.

[0041] In this embodiment, the absolute value of the difference between the number of turns of the first electrode plate 301 and the number of turns of the second electrode plate 302 is 1.

[0042] Specifically, the first electrode plate 301 is electrically connected to a first potential to form an upper electrode plate or a lower electrode plate, and the second electrode plate 302 is electrically connected to a second potential to form a lower electrode plate or an upper electrode plate corresponding to the first electrode plate 301. The first potential and the second potential are opposite, and any three consecutive electrode plates (two first electrode plates and a second electrode plate between two first electrode plates, or two second electrode plates and a first electrode plate between two second electrode plates) constitute a parallel capacitor, so the number of turns of the first electrode plate 301 is not equal to the number of turns of the second electrode plate 302.

[0043] In other embodiments, the number of turns of the first electrode plate and the number of turns of the second electrode plate may be the same.

[0044] In this embodiment, the intervals between adjacent first electrode plates 301 and second electrode plates 302 may be the same.

[0045] That is, the alternately arranged circles of first electrode plates 301 and circles of second electrode plates 302 are arranged at equal intervals. A capacitor unit is formed between adjacent first electrode plates 301 and second electrode plates 302. This design makes the capacitance values ​​of multiple capacitor units more uniform and the distribution of capacitance density more uniform, which is convenient for circuit design.

[0046] In other embodiments, the spacing between adjacent first electrode plates and second electrode plates may not be completely the same. By designing first electrode plates and second electrode plates with different spacings, the diversity of capacitors can be improved to meet different practical application requirements and improve the flexibility and diversity of device manufacturing.

[0047] In this embodiment, the widths of several circles of the first electrode plates 301 are the same; the widths of several circles of the second electrode plates 302 are the same.

[0048] In the above embodiment, by forming the first electrode plate and the second electrode plate of the same width, when forming several circles of the first electrode plate 301 or forming several circles of the second electrode plate 302, the process of the first electrode plate 301 and the second electrode plate 302 can be better controlled, which can reduce the manufacturing cost and improve the manufacturing efficiency.

[0049] In this embodiment, the widths of the first electrode plate 301 and the second electrode plate 302 may be the same.

[0050] In the above embodiment, by setting the first electrode plate and the second electrode plate of the same width, when the first electrode plate 301 and the second electrode plate 302 are formed by the same process, the processing technology of forming the first electrode plate 301 and the second electrode plate 302 can be better controlled, which can reduce the manufacturing cost and thus improve the manufacturing efficiency.

[0051] In other embodiments, the widths of the first electrode plate and the second electrode plate may be different.

[0052] In this embodiment, the first electrode plate 301 and the second electrode plate 302 have a first width, and there is a first interval between adjacent first electrode plates 301 and second electrode plates 302 . The ratio of the first width to the first interval is in the range of 0.5-2.

[0053] In the above embodiment, by setting the first width and the first spacing in a ratio range of 0.5 to 2, the capacitor structure has a sufficiently large capacitance density under a given layout occupation area. In addition, by setting the first width and the first spacing in a ratio range of 0.5 to 2, the setting of the plate width and the plate spacing is combined with the processing equipment or process specifics, so that it is easy to implement in actual process, which can improve the actual product manufacturing yield.

[0054] In this embodiment, the number of the first sections C1 of each circle of the first electrode plates 301 is the same as the number of the second sections C2 of each circle of the second electrode plates 302, so as to ensure that the intervals between adjacent first electrode plates 301 and second electrode plates 302 are the same.

[0055] In this embodiment, the curvature radii of several of the first divisions C1 and the curvature radii of several of the second divisions C2 gradually increase from the inner circle to the outer circle, that is, the curvature radius of the first division C1 in the outermost circle is the largest, and the projection shape of the first division C1 in the outermost circle is a semicircle. From the outermost circle to the inner circle, the curvature radii of the second division C2 and the curvature radii of the first division C1 decrease in sequence according to the arrangement order, and the projection shape of the first division C1 or the second division C2 in the innermost circle approaches to a circle.

[0056] In this embodiment, the curvature radius of the first division C1 of the first electrode plate 301 in each circle is different, and the curvature radius of the first electrode plate 301 in each circle gradually increases from the inner circle to the outer circle; the curvature radius of the second division C2 of the second electrode plate 302 in each circle is different, and the curvature radius of the second division C2 of the second electrode plate 302 in each circle gradually increases from the inner circle to the outer circle.

[0057] In this embodiment, the radius of curvature of the first electrode plate 301 in each circle gradually increases from the inner circle to the outer circle. Specifically, the radius of curvature of the first division C1 in each circle gradually increases from the inner circle to the outer circle.

[0058] In this embodiment, the curvature radius of the second section C2 of each circle of the second electrode plate 302 gradually increases from the inner circle to the outer circle. Specifically, the curvature radius of the second section C2 of each circle gradually increases from the inner circle to the outer circle.

[0059] In this embodiment, the "petal"-shaped first sub-section C1 and the second sub-section C2 have a larger specific surface area, so that under the same limited layout area, the capacitance density of the formed capacitor can be higher and the layout area can be saved.

[0060] In one embodiment, the number of the first sections C1 and the number of the second sections C2 may include three, four, five or six.

[0061] In this embodiment, the number of the first sub-portions C1 in one circle of the first electrode plate 301 and the number of the second sub-portions C2 in one circle may include four.

[0062] In one embodiment, each "petal"-shaped first division C1 is connected and closed to form the first electrode plate 301, and the projection shape of the first electrode plate 301 may include a "flower" shape; each "petal"-shaped second division C2 is connected and closed to form the second electrode plate 302, and the projection shape of the second electrode plate 302 may include a "flower" shape.

[0063] In this embodiment, the projection shapes of the first sub-portions C1 in the second direction are the same, and the perimeters of the first sub-portions C1 are the same. That is, the thickness and effective perimeter of the first sub-portions C1 are the same, and the first sub-portions C1 have the same specific surface area. Therefore, it is convenient to control and design the capacitance value of the capacitor structure.

[0064] In this embodiment, the projection shapes of the plurality of second sub-portions C2 in the second direction are the same, and the perimeters of the plurality of second sub-portions C2 are the same. That is, the thickness and effective perimeter of the plurality of second sub-portions C2 are the same, and the plurality of second sub-portions C2 have the same specific surface area. Thus, it is convenient to control and design the capacitance value of the capacitor structure.

[0065] In the above embodiment, by making the projection shapes of several first divisions C1 in the second direction the same, the circumferences of several first divisions C1 the same, and the projection shapes of several second divisions C2 in the second direction the same, and the circumferences of several second divisions C2 the same, the processing of each first division and second division can be achieved based on the same processing technology, which can simplify the processing technology and improve the processing efficiency.

[0066] In this embodiment, the capacitor structure includes a multi-layer electrode plate structure, the multi-layer electrode plate structure is stacked in a second direction Y, and the multi-layer electrode plate structure is electrically connected to each other, and the second direction Y is perpendicular to the first direction X.

[0067] In this embodiment, the projection shape of the first section C1 in the second direction Y includes a “petal” shape; the projection shape of the second section C2 in the second direction Y includes a “petal” shape.

[0068] In this embodiment, the electrical connection between the multi-layer electrode plate structures may include: the first electrode plates 301 of the multi-layer electrode plate structures are electrically connected to each other, and the second electrode plates 302 of the multi-layer electrode plate structures are electrically connected to each other.

[0069] In this embodiment, the capacitor structure also includes: a connection structure located between the electrode plate structures of adjacent layers, and the connection structure includes: a first electrical connection layer 304 electrically connecting the first electrode plate 301 of the adjacent layer, and a second electrical connection layer 305 electrically connecting the second electrode plate 302 of the adjacent layer.

[0070] Figure 3 and Figure 4 FIG. 4 schematically shows a stacking structure of three-layer electrode plate structures and two-layer connection structures in the second direction Y. FIG.

[0071] The connection structure can connect the capacitor units formed by adjacent first electrode plates 301 and second electrode plates 302 among a plurality of first electrode plates 301 and a plurality of second electrode plates 302, and then through the subsequent electrical connection of the first conductive structure 307 and the second conductive structure 308, the plurality of capacitor units formed by adjacent first electrode plates 301 and second electrode plates 302 can be connected in parallel, which can greatly improve the capacitance density under limited floor space.

[0072] Specifically, in three consecutive electrode plates (two first electrode plates 301 and a second electrode plate 302 located between the two first electrode plates 301, or two second electrode plates 302 and a first electrode plate 301 located between the two second electrode plates 302), adjacent first electrode plates 301 and second electrode plates 302 constitute a capacitor unit, and the three consecutive electrode plates constitute two capacitor units. The connection structure is connected to the three consecutive electrode plates respectively, so that the two capacitor units constituted by the three consecutive electrode plates can be connected to improve the capacitance density.

[0073] The width of the first electrical connection layer 304 is smaller than or equal to the width of the first electrode plate 301 ; the width of the second electrical connection layer 305 is smaller than or equal to the width of the second electrode plate 302 .

[0074] In this embodiment, the width of the first electrical connection layer 304 is smaller than the width of the first electrode plate 301; the width of the second electrical connection layer 305 is smaller than the width of the second electrode plate 302. Therefore, when a groove is formed in the dielectric structure to form the first electrical connection layer 304 and the second electrical connection layer 305, the width of the groove is smaller than the width of the first electrode plate 301 and the width of the second electrode plate 302. Therefore, the process window when forming the groove is large, and it is easy to form contact with the first electrode plate 301 and the second electrode plate 302, which is easy to implement in terms of process.

[0075] In another embodiment, the width of the first electrical connection layer is equal to the width of the first electrode plate; the width of the second electrical connection layer is equal to the width of the second electrode plate. Thus, the interlayer spacing of the connection structure is the same as the interlayer spacing of the electrode plate structure, which facilitates the calculation of the overall capacitance value of the connection structure and the electrode plate structure.

[0076] In this embodiment, the projection pattern of the first electrical connection layer 304 is the same as the projection pattern of the first electrode plate 301; the projection pattern of the second electrical connection layer 305 is the same as the projection pattern of the second electrode plate 302. Thus, it can be ensured that the connection structure is in full contact with and electrically connected to the electrode plate structure, and the capacitance value between the first electrical connection layer 304 and the second electrical connection layer 305 is easy to calculate.

[0077] It should be noted that the electrode plate structures in this embodiment and the connection structures between adjacent layers of electrode plate structures are vertically stacked in a direction perpendicular to the substrate surface, and the projection figures described in this embodiment are all projections on the substrate surface.

[0078] In this embodiment, the material of the first electrical connection layer 304 is the same as that of the first electrode plate 301 ; the material of the second electrical connection layer 305 is the same as that of the second electrode plate 302 .

[0079] In the above embodiment, by forming the first electrical connection layer 304 and the first electrode plate 301 of the same material, and the second electrical connection layer 305 and the second electrode plate 302 of the same material, the process of forming the first electrical connection layer 304 is compatible with the process of forming the first electrode plate 301, and the process of forming the second electrical connection layer 305 is compatible with the process of forming the second electrode plate 302, which can reduce the process difficulty and improve the processing efficiency.

[0080] In this embodiment, the connection structure may also include: a first adhesion layer and a first barrier layer located between the first electrical connection layer 304 and the dielectric structure, the first adhesion layer is located between the first barrier layer and the first electrical connection layer 304; a second adhesion layer and a second barrier layer located between the second electrical connection layer 305 and the dielectric structure, the second adhesion layer is located between the second barrier layer and the second electrical connection layer 305.

[0081] In this embodiment, the material of the first electrical connection layer 304 may include metal; the metal may include: a combination of one or more of copper, aluminum, tungsten, cobalt, nickel and tantalum.

[0082] In this embodiment, the material of the first electrical connection layer 304 may include copper.

[0083] In this embodiment, the material of the second electrical connection layer 305 may include metal; the metal may include: a combination of one or more of copper, aluminum, tungsten, cobalt, nickel and tantalum.

[0084] In this embodiment, the material of the second electrical connection layer 305 includes copper. The resistance of copper material is relatively low, which can reduce the energy loss in the signal transmission process. In addition, copper has a high electrical mobility, which can improve the operating speed and reliability of the chip. Furthermore, copper has good adhesion to dielectric insulating materials such as silicon dioxide, which can reduce the contact resistance between the connection structure and the dielectric structure. Furthermore, the semiconductor copper process has stronger applicability and is suitable for different chip manufacturing processes such as CMOS and BiCMOS.

[0085] In one embodiment, the first adhesion layer and the second adhesion layer are made of the same material; the first adhesion layer and the second adhesion layer may include metal, and the metal may include tantalum.

[0086] In one embodiment, the first barrier layer and the second barrier layer are made of the same material; the first barrier layer and the second barrier layer may include metal nitride, and the metal nitride may include titanium nitride or tantalum nitride.

[0087] In other embodiments, the material of the first electrical connection layer may be different from the material of the first electrode plate; the material of the second electrical connection layer may be different from the material of the second electrode plate.

[0088] In this embodiment, the material of the first electrode plate 301 is the same as that of the second electrode plate 302 .

[0089] In the above embodiment, the first electrode plate 301 and the second electrode plate 302 are made of the same material, so that the process of forming the electrode plate structure is compatible with the process of forming the connection structure, which can reduce the difficulty of the process.

[0090] In one embodiment, the material of the first electrode plate 301 may include metal; the material of the second electrode plate 302 may include metal; the metal may include: a combination of one or more of copper, aluminum, tungsten, cobalt, nickel and tantalum.

[0091] In this embodiment, the material of the first electrode plate 301 and the material of the second electrode plate 302 may include copper.

[0092] In the above embodiment, the resistance of the copper material is relatively low, which can reduce the energy loss during signal transmission; and copper has a high electrical mobility, which can improve the operating speed and reliability of the chip; in addition, copper has good adhesion to dielectric insulating materials such as silicon dioxide, which can reduce the contact resistance between the connection structure and the dielectric structure; the semiconductor copper process also has stronger applicability and is suitable for different chip manufacturing processes such as CMOS and BiCMOS.

[0093] In other embodiments, the material of the first electrode plate may be different from the material of the second electrode plate.

[0094] In this embodiment, the dielectric structure may include several layers of first dielectric layers 303 and several layers of second dielectric layers 306, one layer of the first dielectric layer 303 is located between several layers of adjacent first electrode plates 301 and second electrode plates 302 of the electrode plate structure, and one layer of the second dielectric layer 306 is located between several layers of adjacent first electrical connection layers 304 and second electrical connection layers 305 of the connection structure.

[0095] In the above embodiment, a second dielectric layer 306 is provided between the first electrical connection layer 304 and the second electrical connection layer 305 of the connection structure, and the connection structure is connected to the electrode plate structure. Capacitors can also be formed between several circles of the first electrical connection layer 304 and several circles of the second electrical connection layer 305, thereby increasing the overall capacitance value of the capacitor structure and further improving the capacitance density of the capacitor structure.

[0096] In this embodiment, the first dielectric layer 303 and the second dielectric layer 306 are made of the same material. The first dielectric layer 303 and the second dielectric layer 306 are made of the same material, so that the first dielectric layer 303 and the second dielectric layer 306 have the same dielectric constant, which is convenient for calculating the capacitance value between the electrode plate structures and the capacitance value between the connection structures. At the same time, they can be formed by the same process, which is also easy to implement in terms of process.

[0097] In this embodiment, the material of the first dielectric layer 303 may include a dielectric material, and the dielectric material may include a combination of one or more of silicon oxide, silicon nitride, silicon carbide, silicon oxycarbide, silicon oxynitride, aluminum oxide, aluminum nitride, silicon carbide nitride, and silicon oxycarbon nitride.

[0098] In this embodiment, the material of the second dielectric layer 306 may include a dielectric material, and the dielectric material may include one or more combinations of silicon oxide, silicon nitride, silicon carbide, silicon oxycarbide, silicon oxynitride, aluminum oxide, aluminum nitride, silicon carbide nitride, and silicon oxycarbon nitride.

[0099] In this embodiment, the material of the first dielectric layer 303 and the material of the second dielectric layer 306 may include silicon oxide. Compared with other dielectric layer materials, silicon oxide material has low cost, simple formation process, and is easy to manufacture.

[0100] In other embodiments, the material of the first dielectric layer and the material of the second dielectric layer may include a high dielectric constant material, the dielectric constant of the high dielectric constant material is greater than 3.9, and the high dielectric constant material may include hafnium oxide, zirconium oxide, hafnium silicon oxide, lanthanum oxide, zirconium silicon oxide, titanium oxide, tantalum oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide or aluminum oxide.

[0101] In this embodiment, the capacitor structure may also include: a first conductive structure 307 electrically connected to the plurality of first electrode plates 301; a second conductive structure 308 electrically connected to the plurality of second electrode plates 302, wherein the first conductive structure 307 and the second conductive structure 308 are respectively arranged at opposite ends of the electrode plate structure in the second direction Y, and the electrical connection between the first conductive structure 307 and the second conductive structure 308 enables the capacitor units formed by the plurality of first electrode plates 301 and the plurality of second electrode plates 302 to be connected in parallel, thereby improving the capacitance density.

[0102] In this embodiment, the first conductive structure 307 is parallel to the first direction X, and the second conductive structure 308 is parallel to the first direction X.

[0103] In this embodiment, the first conductive structure 307 and the second conductive structure 308 are used to apply a positive voltage and a negative voltage to the capacitor structure, respectively, so that a voltage difference can be formed between the first electrode plate 301 and the second electrode plate 302 to form a capacitor structure.

[0104] In this embodiment, the first conductive structure 307 and the second conductive structure 308 are made of the same material.

[0105] In this embodiment, the material of the first conductive structure 307 may include metal; the material of the second conductive structure 308 may include metal; the metal may include a combination of one or more of copper, aluminum, tungsten, cobalt, nickel and tantalum.

[0106] In this embodiment, the material of the first conductive structure 307 and the second conductive structure 308 may include copper.

[0107] In this embodiment, the dielectric structure may further include: a third dielectric layer 309 , in which the first conductive structure 307 is located; and a fourth dielectric layer 310 , in which the second conductive structure 308 is located.

[0108] In this embodiment, the third dielectric layer 309 and the fourth dielectric layer 310 are made of the same material.

[0109] In this embodiment, the dielectric constant of the materials of the first dielectric layer 303 and the second dielectric layer 306 is greater than the dielectric constant of the materials of the third dielectric layer 309 and the fourth dielectric layer 310 .

[0110] In the above embodiment, the dielectric constant of the material of the third dielectric layer 309 and the fourth dielectric layer 310 is small, which can reduce the interlayer capacitance and reduce the RC delay. The dielectric constant of the material of the first dielectric layer 303 and the second dielectric layer 306 is large, which can increase the capacitance value of the capacitor formed by the first dielectric layer 303 and the electrode plate structure, and can increase the capacitance value of the capacitor formed by the second dielectric layer 306 and the connection structure, thereby increasing the overall capacitance density of the capacitor structure.

[0111] In this embodiment, the material of the first dielectric layer 303 and the second dielectric layer 306 may include a high dielectric constant material, the dielectric constant of the high dielectric constant material is greater than 3.9, and the high dielectric constant material may include hafnium oxide, zirconium oxide, hafnium silicon oxide, lanthanum oxide, zirconium silicon oxide, titanium oxide, tantalum oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide or aluminum oxide.

[0112] In this embodiment, the materials of the first dielectric layer 303 and the second dielectric layer 306 may include a low dielectric constant material or silicon oxide, and the dielectric constant of the low dielectric constant material is less than 3.9.

[0113] In other embodiments, the materials of the third dielectric layer and the fourth dielectric layer are the same as the materials of the first dielectric layer and the second dielectric layer.

[0114] Figure 8 It is a schematic diagram of the layout of multiple capacitor structures when integrated in an embodiment of the present invention. The layout area occupied by a single capacitor structure is reduced, and the capacitance density of a single capacitor structure is improved, thereby saving layout area and greatly improving the capacitance density while occupying a small area.

[0115] Accordingly, the embodiment of the present invention further provides a method for forming Figures 3 to 8 The method of the capacitor structure comprises:

[0116] providing a substrate;

[0117] A dielectric structure and at least one layer of electrode plate structure are formed on a substrate, wherein the electrode plate structure comprises: a plurality of circles of first electrode plates 301 and a plurality of circles of second electrode plates 302 alternately arranged along a first direction X, wherein the plurality of circles of first electrode plates 301 and the plurality of circles of second electrode plates 302 are separate from each other, wherein the first electrode plate 301 comprises a plurality of connected and closed first subdivisions C1, wherein the projection shape of the first subdivision C1 on the substrate comprises a "petal" type, wherein the second electrode plate 302 comprises a plurality of connected and closed second subdivisions C2, wherein the projection shape of the second subdivision C2 on the substrate comprises a "petal" type, wherein the curvature radii of the plurality of first electrode plates 301 and the curvature radii of the plurality of second electrode plates 302 gradually increase from the inner circle to the outer circle, and wherein the dielectric structure is located between the first electrode plates 301 and the second electrode plates 302 of adjacent layers of the same layer of electrode plate structure.

[0118] In this embodiment, the dielectric structure may include a fourth dielectric layer 310 located on a substrate, and the capacitor structure further includes: a second conductive structure 308 electrically connected to the plurality of second electrode plates 302 , and the second conductive structure 308 is located in the fourth dielectric layer 310 .

[0119] The method for forming the second conductive structure 308 includes: forming a fourth dielectric layer 310 on a substrate; forming an opening (not shown) in the fourth dielectric layer 310; and forming the second conductive structure 308 in the opening.

[0120] In this embodiment, the dielectric structure also includes a first dielectric layer 303 located on the fourth dielectric layer 310, and the first electrode plate 301 and the second electrode plate 302 are formed simultaneously. The formation of the electrode plate structure includes: forming the first dielectric layer 301 on the fourth dielectric layer 310; forming a first groove (not shown) and a second groove (not shown) in the first dielectric layer 301, and the second groove exposes the surface of the second conductive structure 308; forming an electrode material layer (not shown) in the first groove, in the second groove and on the first dielectric layer 303; flattening the electrode material layer until the surface of the first dielectric layer 303 is exposed, forming a first electrode plate 301 in the first groove, forming a second electrode plate 302 in the second groove, and the second electrode plate 302 is electrically connected to the second conductive structure 308.

[0121] In this embodiment, when the electrode plate structure includes multiple layers, it may further include: forming a connection structure between the electrode plate structures of adjacent layers. Specifically, the formation process of the multiple-layer electrode plate structure and the multiple-layer connection structure includes: first forming a first-layer first dielectric layer 303 and an electrode plate structure located in the first dielectric layer 303, then forming a first-layer second dielectric layer 306 and a connection structure located in the second dielectric layer 306 on the first-layer first dielectric layer 303, and then forming a second-layer first dielectric layer 303 and an electrode plate structure located in the first dielectric layer 303 on the first-layer second dielectric layer 306. Repeat the above process multiple times until the formation of the multiple-layer electrode plate structure and the multiple-layer connection structure is completed.

[0122] In other embodiments, two adjacent layers of structures, ie, adjacent electrode plate structures and connecting structures, can be formed simultaneously during the same metal forming process.

[0123] In other embodiments, adjacent three-layer structures, ie, a two-layer electrode plate structure and a connection structure between the two-layer electrode plate structures, can be formed simultaneously during the same metal forming process.

[0124] In this embodiment, the connection structure may include: a first electrical connection layer 304 electrically connecting adjacent first electrode plates 301, and a second electrical connection layer 305 electrically connecting adjacent second electrode plates 302. The first electrical connection layer 304 and the second electrical connection layer 305 of the same layer are formed simultaneously.

[0125] In this embodiment, the dielectric structure may include a second dielectric layer 306, and forming the connection structure may include: forming a second dielectric layer 306 on the first dielectric layer 303 and the electrode plate structure; forming a third groove (not shown) and a fourth groove (not shown) in the second dielectric layer 306, the third groove exposing the top surface of the first electrode plate 301, and the fourth groove exposing the top surface of the second electrode plate 302; forming a connection material layer (not shown) in the third groove, in the fourth groove, and on the second dielectric layer 306; flattening the connection material layer until the surface of the second dielectric layer 306 is exposed, forming a first electrical connection layer 304 in the third groove, the first electrical connection layer 304 is electrically connected to the first electrode plate 301, and forming a second electrical connection layer 305 in the fourth groove, the second electrical connection layer 305 is electrically connected to the second electrode plate 302.

[0126] Furthermore, a first dielectric layer 303 and an electrode plate structure in the first dielectric layer 303 are formed on the second dielectric layer 306 ; a third dielectric layer 309 is formed on the first dielectric layer 303 and the electrode plate structure; and a first conductive structure 309 is formed in the third dielectric layer 304 .

[0127] In the above method for forming the capacitor structure, by forming the electrode plate of the first division of the "petal" shape, the capacitance density of the formed capacitor device can be improved. In addition, the process flow of forming the capacitor structure is simple and easy to implement, which can improve the efficiency and yield of production.

[0128] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A capacitor structure, characterized in that: include: At least one layer of electrode plate structure, the electrode plate structure comprising: a plurality of circles of first electrode plates and a plurality of circles of second electrode plates alternately arranged along a first direction, the plurality of circles of first electrode plates and the plurality of circles of second electrode plates being separate from each other, the first electrode plate comprising a plurality of connected and closed first subdivisions, the shape of the first subdivisions comprising a "petal" type, the second electrode plate comprising a plurality of connected and closed second subdivisions, the shape of the second subdivisions comprising a "petal" type, the curvature radii of the plurality of first electrode plates and the curvature radii of the plurality of second electrode plates gradually increasing from the inner circle to the outer circle; The dielectric structure is located between the first electrode plate and the second electrode plate in adjacent layers of the same-layer electrode plate structure.

2. The capacitor structure according to claim 1, characterized in that: The first electrode plate and the second electrode plate have a first width, and there is a first interval between adjacent first electrode plates and second electrode plates. The ratio of the first width to the first interval is in the range of 0.5-2.

3. The capacitor structure according to claim 1, characterized in that: The number of the first divisions is the same as the number of the second divisions; the number of the first divisions and the number of the second divisions include three, four, five or six.

4. The capacitor structure according to claim 1, characterized in that: The electrode plate structure is multi-layered, the multi-layered electrode plate structure is stacked in a second direction, and the electrode plate structures in adjacent layers are electrically connected, and the second direction is perpendicular to the first direction.

5. The capacitor structure according to claim 4, characterized in that: The capacitor structure further includes: a connection structure located between the electrode plate structures of adjacent layers, and the electrode plate structures of adjacent layers are electrically connected via the connection structure.

6. The capacitor structure according to claim 5, characterized in that: The connection structure includes: a first electrical connection layer and a second electrical connection layer, the first electrical connection layer electrically connects the first electrode plates of adjacent layers, and the second electrical connection layer electrically connects the second electrode plates of adjacent layers.

7. The capacitor structure according to claim 6, characterized in that: The dielectric structure is also located between the first electrical connection layer and the second electrical connection layer adjacent to each other in the same layer.

8. The capacitor structure according to claim 6, characterized in that: The width of the first electrical connection layer is less than or equal to the width of the first electrode plate; the width of the second electrical connection layer is less than or equal to the width of the second electrode plate.

9. The capacitor structure according to claim 6, characterized in that: The material of the first electrical connection layer is the same as that of the first electrode plate; the material of the second electrical connection layer is the same as that of the second electrode plate; and the material of the first electrode plate is the same as that of the second electrode plate.

10. A method for forming a capacitor structure according to any one of claims 1 to 9, characterized in that: include: providing a substrate; A dielectric structure and at least one layer of electrode plate structure are formed on a substrate, wherein the electrode plate structure comprises: a plurality of circles of first electrode plates and a plurality of circles of second electrode plates alternately arranged along a first direction, the plurality of circles of first electrode plates and the plurality of circles of second electrode plates being separate from each other, the first electrode plate comprising a plurality of connected and closed first divisions, the projection shape of the first divisions on the substrate comprising a "petal" type, the second electrode plate comprising a plurality of connected and closed second divisions, the projection shape of the second divisions on the substrate comprising a "petal" type, the curvature radii of the plurality of first electrode plates and the curvature radii of the plurality of second electrode plates gradually increase from the inner circle to the outer circle, and the dielectric structure is located between the first electrode plates and the second electrode plates of adjacent layers of the same layer of electrode plate structure.

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