Capacitor structure and preparation method thereof, and memory

Abstract

The present disclosure provides a capacitor structure, a preparation method thereof, and a memory, and relates to the field of semiconductor technology. The capacitor structure includes a first capacitor unit and a second capacitor unit arranged in a stacked manner. The first capacitor unit includes a plurality of first capacitors arranged in an array, and the second capacitor unit includes a plurality of second capacitors arranged in an array, and an electrode of a first capacitor and an electrode of a second capacitor are correspondingly connected. A supporting layer is provided between the first capacitor unit and the second capacitor unit, and the supporting layer includes a plurality of supporting structures arranged in an array, and the supporting structure is located between the first capacitor and the second capacitor. The cross-sectional area of ​​the electrode of the first capacitor close to the support structure is larger than the cross-sectional area of ​​the electrode of the second capacitor close to the support structure. The capacitor structure reduces the difficulty of aligning the two stacked capacitors by reducing the cross-sectional area of ​​the end where the electrode of the second capacitor is connected to the electrode of the first capacitor, thereby solving the technical problem that the preparation of multilayer capacitors is more difficult.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a capacitor structure and a preparation method thereof, and a memory. Background Art

[0002] Memories, such as dynamic random access memory (DRAM) or static random access memory (SRAM), are widely used in the fields of computers and communications.

[0003] Taking DRAM as an example, it includes multiple memory cells, each of which includes a transistor and a capacitor. The capacitor stores data information, and the transistor controls the reading and writing of data information in the capacitor. The storage capacity of the capacitor affects the storage performance of the DRAM. In related art, capacitors include multiple layers of interconnected capacitors, which can effectively increase the storage capacity of the capacitor.

[0004] However, as DRAM manufacturing processes shrink, multilayer capacitors become more difficult to prepare and have poor connection stability, affecting DRAM storage performance. Summary of the Invention

[0005] The embodiments of the present disclosure provide a capacitor structure and a preparation method thereof, and a memory, which can solve the problems of difficulty in capacitor preparation and low connection stability, and help solve the problem of the capacitor structure affecting the storage performance of the memory.

[0006] In a first aspect, an embodiment of the present disclosure provides a capacitor structure comprising a first capacitor unit and a second capacitor unit arranged in a stacked manner. The first capacitor unit comprises a plurality of first capacitors arranged in an array, the second capacitor unit comprises a plurality of second capacitors arranged in an array, and an electrode of a first capacitor and an electrode of a second capacitor are connected correspondingly. A supporting layer is provided between the first capacitor unit and the second capacitor unit, the supporting layer comprising a plurality of supporting structures arranged in an array, and the supporting structure is located between the first capacitor and the second capacitor. The cross-sectional area of ​​the electrode of the first capacitor close to the supporting structure is greater than the cross-sectional area of ​​the electrode of the second capacitor close to the supporting structure.

[0007] In the above-mentioned capacitor structure, the first capacitor unit and the second capacitor unit are stacked, and the electrode of the first capacitor unit is correspondingly connected to the electrode of the second capacitor unit, thereby improving the aspect ratio of the capacitor structure. A support structure is provided at the connection between the first capacitor and the second capacitor, thereby helping to improve the stability of the connection between the electrode of the first capacitor and the electrode of the second capacitor, thereby helping to improve the stability and reliability of the capacitor structure. In addition, the cross-sectional area of ​​the electrode of the first capacitor close to the support structure is larger than the cross-sectional area of ​​the electrode of the second capacitor close to the support structure, thereby allowing the electrodes of the first capacitor and the second capacitor to overlap and connect at a larger position deviation, which is not only beneficial to reducing the difficulty of preparing the capacitor structure, but also beneficial to preventing the electrodes of the first capacitor and the second capacitor from short-circuiting at the connection, thereby improving the yield rate and reliability of the capacitor structure.

[0008] In a second aspect, an embodiment of the present disclosure further provides a method for preparing a capacitor structure. The method for preparing the capacitor structure includes: providing a base layer; forming a first capacitor unit, the first capacitor unit is located on the base layer, and the first capacitor unit includes a plurality of first capacitors arranged in an array; forming a support layer, the support layer is located on the first capacitor unit, and the support layer includes a plurality of support structures arranged in an array; forming a second capacitor unit, the second capacitor unit is located on the support layer, and the second capacitor unit includes a plurality of second capacitors arranged in an array, and an electrode of a first capacitor and an electrode of a second capacitor are correspondingly connected; wherein the support structure is located between the first capacitor and the second capacitor, and the cross-sectional area of ​​the electrode of the first capacitor close to the support structure is larger than the cross-sectional area of ​​the electrode of the second capacitor close to the support structure.

[0009] In the method for preparing the capacitor structure in the embodiment of the present disclosure, a first capacitor unit is formed on a base layer, a second capacitor unit is formed on the first capacitor unit, and the first capacitor in the first capacitor unit and the second capacitor in the second capacitor unit are connected to each other, which is beneficial to improving the aspect ratio of the capacitor structure. In addition, the support structure is located between the first capacitor and the second capacitor, and the cross-sectional area of ​​the electrode of the first capacitor close to the support structure is larger than the cross-sectional area of ​​the electrode of the second capacitor close to the support structure, which is beneficial to reducing the difficulty of stacking the second capacitor unit and the first capacitor unit, improving the yield rate of the capacitor structure and the reliability of the connection between the electrode of the first capacitor and the electrode of the second capacitor in the capacitor structure.

[0010] In a third aspect, embodiments of the present disclosure further provide a memory device. The memory device includes a base layer and the aforementioned capacitor structure, wherein the capacitor structure is disposed on the base layer; the base layer includes a substrate, a transistor structure, a word line, and a bit line, wherein the transistor structure, the word line, and the bit line are all disposed in the substrate; the source of the transistor structure is connected to the bit line, the gate of the transistor structure is connected to the word line, and the drain of the transistor structure is connected to the corresponding electrode of the first capacitor unit of the capacitor structure.

[0011] The memory provided above includes a structure identical to the capacitor structure described above, and has the same or corresponding technical effects as the above capacitor structure, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of the base layer in some optional embodiments of the present disclosure;

[0013] Figure 2 Schematic diagram of forming a first dielectric layer on a base layer in some optional embodiments of the present disclosure;

[0014] Figure 3 Schematic diagram of forming a first channel on a first dielectric layer in some optional embodiments of the present disclosure;

[0015] Figure 4 Schematic diagram of forming a first conductive layer in a first channel in some optional embodiments of the present disclosure;

[0016] Figure 5 Schematic diagram of removing the first conductive layer on the side of the first dielectric layer facing away from the base layer in some optional embodiments of the present disclosure;

[0017] Figure 6 Schematic diagram of forming a support material layer in some optional embodiments of the present disclosure;

[0018] Figure 7 Schematic diagram of forming a second dielectric layer in some optional embodiments of the present disclosure;

[0019] Figure 8 Schematic diagram of forming a second channel in some optional embodiments of the present disclosure;

[0020] Figure 9 Schematic diagram of forming a second conductive layer in some optional embodiments of the present disclosure;

[0021] Figure 10 Schematic diagram of the connection between the electrode of the first capacitor and the electrode of the second capacitor in some optional embodiments of the present disclosure Figure 1 ;

[0022] Figure 11 Schematic diagram of the connection between the electrode of the first capacitor and the electrode of the second capacitor in some optional embodiments of the present disclosure Figure 2 ;

[0023] Figure 12 Schematic diagram of removing the second conductive layer on the side of the second dielectric layer facing away from the base layer in some optional embodiments of the present disclosure;

[0024] Figure 13 Schematic diagram of forming a third channel in the second dielectric layer in some optional embodiments of the present disclosure;

[0025] Figure 14 Schematic diagram of forming a third channel in the first dielectric layer and the support material layer in some optional embodiments of the present disclosure;

[0026] Figure 15 Schematic diagram of forming a capacitor dielectric layer and an electrode in the third trench in some optional embodiments of the present disclosure;

[0027] Figure 16 Schematic diagram of a support structure in which the molecular weight ratio of boron to nitrogen is 2:3 in some optional embodiments of the present disclosure;

[0028] Figure 17 Schematic diagram of a support structure in which the molecular weight ratio of boron to nitrogen is 1:2 in some optional embodiments of the present disclosure;

[0029] Figure 18 Schematic diagram of a support structure in which the molecular weight ratio of boron to nitrogen is 1:3 in some optional embodiments of the present disclosure;

[0030] Figure 19 Schematic diagram of a support structure in which the molecular weight ratio of boron to nitrogen is 1:4 in some optional embodiments of the present disclosure;

[0031] Figure 20 Flowchart of a method for preparing a capacitor structure in some optional embodiments of the present disclosure.

[0032] Description of reference numerals:

[0033] 100 - base layer; 110 - substrate; 111 - active area; 120 - bit line; 130 - capacitor plug; 140 - contact pad; 150 - shallow trench isolation;

[0034] 200 - first capacitor unit; 210 - first capacitor; 211 - first electrode; 212 - second electrode; 213 - first capacitor dielectric layer; 201 - first conductive layer;

[0035] 300 - second capacitor unit; 310 - second capacitor; 311 - third electrode; 312 - fourth electrode; 313 - second capacitor dielectric layer; 314 - first extension segment; 315 - second extension segment; 301 - second conductive layer;

[0036] 400-support layer; 410-support structure; 401-support material layer;

[0037] 500 - first dielectric layer; 510 - first sub-dielectric layer; 520 - first auxiliary support material layer; 521 - first auxiliary support structure; 530 - second sub-dielectric layer; 540 - second auxiliary support material layer; 541 - second auxiliary support structure; 501 - first channel; 502 - third channel;

[0038] 600 - second dielectric layer; 610 - third sub-dielectric layer; 620 - third auxiliary support material layer; 621 - third auxiliary support structure; 601 - second channel. DETAILED DESCRIPTION

[0039] In related art, capacitors are configured with multiple layers of capacitors to improve their aspect ratio. However, during the stacking process, alignment deviations between adjacent capacitors can easily occur. This can cause the electrodes of one capacitor in one layer to connect to the electrodes of two capacitors in the next layer, resulting in a short circuit.

[0040] Therefore, although the capacitor formed by stacking multiple layers of capacitors can improve the aspect ratio of the capacitor, it requires higher preparation precision for each layer of capacitors and is more difficult to prepare.

[0041] Based on the above technical problems, in the capacitor structure of the embodiment of the present disclosure, by forming a first capacitor unit and a second capacitor unit, a first capacitor in the first capacitor unit is connected to a second capacitor in the second capacitor unit, so as to increase the aspect ratio of the capacitor structure. In addition, the cross-sectional area of ​​the electrode of the first capacitor close to the support structure is larger than the cross-sectional area of ​​the electrode of the second capacitor close to the support structure, which is beneficial to reduce the difficulty of aligning the second capacitor with the corresponding first capacitor, and further helps to reduce the difficulty of manufacturing the capacitor structure.

[0042] In order to make the above-mentioned purpose, features and advantages of the embodiments of the present disclosure more obvious and easy to understand, the following will be combined with the embodiments of the present disclosure. Figures 1 to 20 , clearly and completely describes the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of them. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0043] Reference Figure 15In some optional embodiments, the capacitor structure provided by the present disclosure includes a first capacitor unit 200 and a second capacitor unit 300 arranged in a stacked manner. The first capacitor unit 200 includes a plurality of first capacitors 210 arranged in an array, and the second capacitor unit 300 includes a plurality of second capacitors 310 arranged in an array, and an electrode of a first capacitor 210 is connected to an electrode of a second capacitor 310. In some optional embodiments, the first capacitor 210 and the second capacitor 310 correspond one to one. Exemplarily, a second capacitor 310 in the second capacitor unit 300 is stacked on the first capacitor 210 in the corresponding first capacitor unit 200.

[0044] Reference Figure 15 In some optional embodiments, the first capacitor unit 200 and the second capacitor unit 300 are stacked in a first direction. For example, the first direction can be the thickness direction of the first capacitor unit 200 and the second capacitor unit 300. For example, the first direction can be Figure 15 The direction shown by the z-axis.

[0045] In some optional embodiments, the plurality of first capacitors 210 in the first capacitor unit 200 are arranged in parallel and spaced apart. The plurality of second capacitors 310 in the second capacitor unit 300 are arranged in parallel and spaced apart. Optionally, the first capacitors 210 in the first capacitor unit 200 extend in the first direction. The second capacitors 310 in the second capacitor unit 300 extend in the first direction.

[0046] In some optional embodiments, the first capacitor 210 and the second capacitor 310 may be columnar structures. Further, optionally, the first capacitor 210 and the second capacitor 310 may extend in the direction of the axis of the columnar structure.

[0047] Reference Figure 15 In some optional embodiments, a support layer 400 is provided between the first capacitor unit 200 and the second capacitor unit 300. The support layer 400 includes a plurality of support structures 410 arranged in an array. The support structure 410 is located between the first capacitor 210 and the second capacitor 310, so as to provide a support effect for the connection between the first capacitor 210 and the second capacitor 310 through the support structure 410, thereby improving the stability and reliability of the connection between the first capacitor 210 and the second capacitor 310.

[0048] In some optional embodiments, at least a portion of the second capacitor 310 near one end of the first capacitor 210 is embedded in the support layer 400. Exemplarily, the second capacitor 310 is embedded in the support layer 400 along the thickness direction of the support layer 400, wherein the thickness direction of the support layer 400 is the first direction.

[0049] In the above embodiment, the support structure 410 formed by the support layer 400 can be supported between two adjacent second capacitors 310 respectively, and thus the force perpendicular to the extension direction of the second capacitor 310 can be transferred to the support layer 400, which is beneficial to prevent the second capacitor 310 from tilting and improve the stability and reliability of the capacitor structure.

[0050] Reference Figures 11 to 15 In some optional embodiments, the cross-sectional area of ​​the side of the electrode of the first capacitor 210 close to the support structure 410 is greater than the cross-sectional area of ​​the side of the electrode of the second capacitor 310 close to the support structure 410. Exemplarily, the cross-sectional area of ​​the side of the electrode of the first capacitor 210 close to the support structure 410 is: the area of ​​the cross section of the side of the electrode of the first capacitor 210 close to the support structure 410, and perpendicular to the extension direction of the first capacitor 210. The cross-sectional area of ​​the side of the electrode of the second capacitor 310 close to the support structure 410 is: the area of ​​the cross section of the side of the electrode of the second capacitor 310 close to the support structure 410, and perpendicular to the extension direction of the second capacitor 310.

[0051] According to some optional embodiments, the electrode of the first capacitor 210 has a first end and a second end opposite to each other in its extension direction. The electrode of the second capacitor 310 has a first end and a second end opposite to each other in its extension direction. As an optional embodiment, the first end of the first capacitor 210 in the extension direction is Figure 15 The first capacitor 210 shown in FIG is close to one end of the bottom in its extending direction. The second end of the first capacitor 210 in the extending direction is Figure 15 The first capacitor 210 shown in FIG is close to the top end in its extension direction. Figure 15 The first end of the electrode of the first capacitor 210 is connected to the second end of the electrode of the second capacitor 310. The end surface area of ​​the first end of the electrode of the first capacitor 210 is larger than the end surface area of ​​the second end of the second capacitor 310. It should be noted that the "end surface area of ​​the electrode of the first capacitor 210" here refers to the area of ​​the end surface perpendicular to the extension direction of the first capacitor 210. The end surface area of ​​the electrode of the second capacitor 310 is similar and will not be repeated here.

[0052] In the capacitor structure provided by the above embodiment, the cross-sectional area of ​​the electrode of the first capacitor 210 on the side close to the support structure 410 is larger than the cross-sectional area of ​​the electrode of the second capacitor 310 on the side close to the support structure 410, so that the first capacitor 210 and the second capacitor 310 can allow a larger alignment deviation, which is beneficial to reducing the difficulty of preparing the capacitor structure, and is also beneficial to preventing the electrode of the second capacitor 310 from being connected to the electrodes of the two first capacitors 210 at the same time, which is beneficial to preventing the first capacitor 210 from short-circuiting and improving the reliability of the capacitor structure.

[0053] In some optional embodiments, the capacitor structure includes a plurality of stacked capacitor units, each of which includes capacitors arranged in an array. The capacitors in two adjacent capacitor units correspond one to one, and the electrodes of each capacitor are connected to the electrodes of the corresponding capacitors in the adjacent capacitor units.

[0054] Illustratively, in the capacitor structure, the structures of the capacitor units are the same, and the stacking manner of any two adjacent capacitor units is the same as or similar to the stacking manner of the first capacitor unit 200 and the second capacitor unit 300 .

[0055] In some optional embodiments, such as Figure 10 and Figure 11 As shown, the electrode of the second capacitor 310 includes a first extension segment 314 and a second extension segment 315 connected to each other, wherein the first extension segment 314 is close to the support structure 410, and the second extension segment 315 is away from the support structure 410. In a further optional embodiment, the cross-sectional area of ​​at least a portion of the first extension segment 314 is smaller than the cross-sectional area of ​​the corresponding electrode of the first capacitor 210, and the cross-sectional area of ​​at least a portion of the first extension segment 314 is smaller than the cross-sectional area of ​​the second extension segment 315.

[0056] In the capacitor structure provided by the above embodiment, by reducing the cross-sectional area of ​​one end where the electrode of the second capacitor 310 is connected to the electrode of the first capacitor 210, not only can the first capacitor unit 200 and the second capacitor unit 300 be allowed to have a larger alignment deviation, reducing the difficulty of alignment of the first capacitor unit 200 and the second capacitor unit 300, but it is also beneficial to improve the compactness of the second capacitor 310 arranged perpendicular to its extension direction, thereby obtaining a larger capacitor area when the cross-sectional area of ​​the capacitor structure perpendicular to the first direction is constant, thereby benefiting to increase the storage capacity of the capacitor structure. When the capacitor structure is applied to a memory, it is beneficial to improve the performance of the memory in storing data.

[0057] In some optional embodiments, the cross-sectional area of ​​the first extension section 314 gradually increases in a direction away from the support structure 410. In some optional embodiments, the first extension section 314 may be configured as a truncated cone structure or a stepped cone structure.

[0058] The electrode structure of the second capacitor 310 provided in the above embodiment is not only beneficial to improving the regularity of the electrode shape of the second capacitor 310, but also beneficial to preventing local stress concentration in the second capacitor 310, improving the stability of the electrode of the second capacitor 310, and further beneficial to preventing the collapse of the second capacitor unit 300 and / or the first capacitor unit 200.

[0059] Reference Figure 10 and Figure 11In some optional embodiments, the cross-sectional area of ​​one end of the first extension section 314 connected to the second extension section 315 is the same as the cross-sectional area of ​​the second extension section 315. This is beneficial to improving the regularity of the electrode structure of the second capacitor 310, and is beneficial to preventing local stress concentration on the electrode of the second capacitor 310, thereby improving the stability of the structure of the second capacitor 310.

[0060] In some further optional embodiments, the cross-sectional area of ​​the second extension section 315 is equal to the cross-sectional area of ​​the electrode of the corresponding first capacitor 210. This helps to make the arrangement density of the first capacitors 210 in the first capacitor unit 200 consistent with the arrangement density of the second capacitors 310 in the second capacitor unit 300, thereby making the overall arrangement of the first capacitor unit 200 and the second capacitor unit 300 in the capacitor structure more compact, thereby increasing the overall capacitance area of ​​the capacitor structure and increasing the storage capacity of the capacitor structure.

[0061] In some further optional embodiments, the second extension section 315 and the electrode of the first capacitor 210 are both columnar structures. For example, the second extension section 315 and the electrode of the first capacitor 210 are both cylindrical. In further optional embodiments, the diameter of the second extension section 315 is equal to the diameter of the first capacitor 210 connected thereto.

[0062] The capacitor structure provided by the above embodiment, the first capacitor 210 and the second capacitor 310 are arranged in a cylindrical shape, which is beneficial to increasing the capacitance area of ​​the first capacitor 210 and the second capacitor 310, and thus beneficial to increasing the storage capacity of the capacitor structure. In addition, the diameter of the second extension section 315 is equal to that of the electrode connected thereto in the first capacitor 210, which is beneficial to improving the consistency of the electrode of the first capacitor 210 and the electrode of the second capacitor 310, and is beneficial to reducing the impedance value of the electrode in the capacitor structure. Moreover, this can also avoid the cross-section of the overall structure of the second capacitor 310 perpendicular to the first direction being smaller than the cross-sectional area of ​​the electrode of the first capacitor 210 perpendicular to the first direction, and thus can increase the storage capacity of the capacitor structure when the capacitor structure has the same size in the first direction.

[0063] In some optional embodiments, the length of the first extension section 314 in the extension direction of the second capacitor 310 is 8 nm to 12 nm. For example, the length of the first extension section 314 in the extension direction of the second capacitor 310 is 10 nm. In this embodiment, the first extension section 314 can provide sufficient clearance for the connection between the first capacitor unit 200 and the second capacitor unit 300, thereby reducing the difficulty in manufacturing the second capacitor unit 300.

[0064] Reference Figure 15In some optional embodiments, the second capacitor unit 300 is stacked on top of the first capacitor unit 200. Exemplarily, the top of the first capacitor unit 200 is an end of the first capacitor unit 200 along the extension direction of the first capacitor 210.

[0065] The first capacitor 210 includes a first electrode 211 and a second electrode 212. A first capacitor dielectric layer 213 is disposed between the first electrode 211 and the second electrode 212. The second capacitor 310 includes a third electrode 311 and a fourth electrode 312. A second capacitor dielectric layer 313 is disposed between the third electrode 311 and the fourth electrode 312. The first electrode 211 and the third electrode 311 are connected to each other, and the second electrode 212 and the fourth electrode 312 are disposed to each other. The support structure 410 is located between the corresponding second electrode 212 and the fourth electrode 312.

[0066] In some optional embodiments, the support structure 410 has a plurality of mounting grooves, and at least a portion of the first electrode 211 and / or the third electrode 311 is located in the mounting grooves, so that the first electrode 211 and the third electrode 311 can penetrate the support structure 410 and be connected.

[0067] In some optional embodiments, one end of the third electrode 311 connected to the first electrode 211 is at least partially located in the support structure 410. Further optionally, one end of the third electrode 311 connected to the first electrode 211 passes through the support structure 410 and is connected to the first electrode 211. In this way, the support structure 410 can provide support for the third electrode 311 in the second capacitor unit 300, improve the stability of the capacitor structure, and thus help prevent the first capacitor unit 200 and the second capacitor unit 300 from being unstable and collapsing after being stacked. In addition, the third electrode 311 is connected to the first electrode 211 so that the force supported on the third electrode 311 can be transmitted to the first electrode 211, thereby allowing the support structure 410 to provide support for the first electrode 211 and improve the stability of the capacitor structure.

[0068] Reference Figure 10 In some optional embodiments, the sidewalls of the support structure 410 are inclined. In further optional embodiments, as Figure 10 As shown, the cross-sectional area of ​​the support structure 410 on the side close to the first capacitor unit 200 is greater than the cross-sectional area of ​​the support structure 410 on the side close to the second capacitor unit 300. The cross-sectional area of ​​the support structure 410 is the area of ​​the cross section along the direction perpendicular to the first capacitor unit 200 to the second capacitor unit 300. In some optional embodiments, the cross-sectional area of ​​the support structure 410 gradually decreases along the direction from the first capacitor unit 200 to the second capacitor unit 300.

[0069] In the capacitor structure provided by the above embodiment, the sidewalls of the support structure 410 are tilted, which is beneficial to improving the compactness of the assembly between the support structure 410 and the third electrode 311 , thereby enabling the support structure 410 to better provide support for the third electrode 311 .

[0070] In some optional embodiments, the sidewalls of the support structure 410 are supported by the sidewalls of the electrode of the second capacitor 310. In further optional embodiments, the sidewalls of the support structure 410 abut against the sidewalls of the first extension 314. Exemplarily, the sidewalls of the support structure 410 are the inner sidewalls of the mounting groove in the support structure 410. In further optional embodiments, the sidewalls of the support structure 410 can be aligned with the sidewalls of the third electrode 311 of the second capacitor 310, increasing the contact area between the support structure 410 and the third electrode 311, thereby improving the stability of the third electrode 311.

[0071] Reference Figure 10 In some optional embodiments, the angle between the sidewall of the support structure 410 and the preset plane is in the range of 70°-80°. The extending direction of the preset plane is perpendicular to the direction from the first capacitor unit 200 to the second capacitor unit 300.

[0072] In some optional embodiments, the direction from the first capacitor unit 200 to the second capacitor unit 300 may be the extension direction of the first capacitor 210 or the second capacitor 310. For example, the direction from the first capacitor unit 200 to the second capacitor unit 300 may be Figure 10 Optionally, the angle between the side wall of the support structure 410 and the preset plane is Figure 10 Angle β is shown.

[0073] During the preparation of the capacitor structure, the support structure 410 is first formed, and then the electrode of the second capacitor 310 that passes through the support structure 410 is formed on the support structure 410. In the above embodiment, when the size and structure of the second capacitor 310 are constant, the larger the angle between the side wall of the support structure 410 and the preset plane, the larger the cross-sectional area of ​​the electrode of the second capacitor 310 close to the support structure 410, and thus the smaller the allowable alignment deviation between the electrode of the second capacitor 310 and the electrode of the first capacitor 210. The smaller the angle between the side wall of the support structure 410 and the preset plane, the smaller the cross-sectional area of ​​the electrode of the second capacitor 310 close to the support structure 410, the greater the impedance at the connection between the electrode of the second capacitor 310 and the electrode of the first capacitor 210, and the poorer the stability of the connection between the electrode of the second capacitor 310 and the electrode of the first capacitor 210.

[0074] In the above embodiment, the angle between the sidewall of the support structure 410 and the preset plane is in the range of 70°-80°, which not only ensures that the electrodes of the second capacitor 310 and the first capacitor 210 can tolerate a larger alignment deviation, reducing the difficulty of stacking the second capacitor 310 and the first capacitor 210, but also avoids a large impedance at the connection between the second capacitor 310 and the first capacitor 210, ensuring the stability of the connection between the electrodes of the second capacitor 310 and the first capacitor 210. In a further preferred embodiment, the angle between the sidewall of the support structure 410 and the preset plane can be 72°, 75°, or 78°.

[0075] In some optional embodiments, the material of the support structure 410 is silicon boron nitride, wherein the molecular weight ratio of boron to nitrogen is 1:3. Figures 6 to 8 As shown, in the process of forming the support structure 410 , a support material layer 401 may be formed first, and then a trench or a through hole for accommodating the electrode of the second capacitor 310 may be formed in the support material layer 401 through an etching process.

[0076] Reference Figures 16 to 19 In the process of realizing the capacitor structure provided by the present disclosure, the inventors found that during the etching process, different shapes of channels can be formed by doping different proportions of boron elements in the silicon nitride material. Figure 16 and Figure 17 As shown in Figure 1, the greater the proportion of boron, the more obvious the arched concave surface formed on the sidewall of the channel. Figure 19 As shown in FIG, the smaller the angle between the sidewall of the formed channel and the preset plane is. In the case where the molecular weight ratio of boron to nitrogen is 1:3, as shown in FIG. Figure 18 The support material layer 401 can be etched to form a channel or through hole with an angle between the inner sidewall of the channel and the preset plane ranging from 70° to 80°, thereby forming a support structure 410.

[0077] Reference Figure 15 In some optional embodiments, the capacitor structure further includes a plurality of auxiliary support structures, at least some of which are located between the corresponding second electrode 212 and the fourth electrode 312 and abut against the side of the support structure 410 close to the second electrode 212.

[0078] In some optional embodiments, such as Figure 15As shown, the plurality of auxiliary support structures include a second auxiliary support structure 541, and the second auxiliary support structure 541 abuts against the support structure 410. Optionally, the second auxiliary support structure 541 has a mounting groove, and the electrode of the first capacitor 210 passes through the mounting groove of the second auxiliary support structure 541 and is connected to the electrode of the second capacitor 310. In some further optional embodiments, the first electrode 211 of the first capacitor 210 passes through the second auxiliary support structure 541 and is connected to the third electrode 311 of the second capacitor 310. Exemplarily, one end of the first electrode 211 connected to the third electrode 311 is embedded in the second auxiliary support structure 541, and one end of the third electrode 311 connected to the first electrode 211 is embedded in the support structure 410.

[0079] In the above embodiment, the second auxiliary support structure 541 can provide support for one end of the first electrode 211 connected to the third electrode 311, thereby helping to transfer the force of the first electrode 211 perpendicular to its extension direction to the auxiliary support structure. The support structure 410 provides support for one end of the third electrode 311 connected to the first electrode 211, thereby helping to transfer the force of the third electrode 311 perpendicular to its extension direction to the support structure 410. Therefore, the second auxiliary support structure 541 and the support structure 410 are beneficial to reducing the shear stress at the connection between the first electrode 211 and the third electrode 311, thereby helping to improve the stability of the connection between the first electrode 211 and the third electrode 311, thereby improving the stability and reliability of the overall structure of the capacitor structure, and helping to prevent the capacitor structure from collapsing.

[0080] Reference Figure 15 A portion of the plurality of auxiliary support structures supports the sidewalls of the first capacitor 210. Exemplarily, the plurality of auxiliary support structures includes a first auxiliary support structure 521. The first capacitor 210 extends through the first auxiliary support structure 521, and both ends of the first capacitor 210 in the extension direction at least partially extend beyond the first auxiliary support structure 521.

[0081] In some optional embodiments, the plurality of auxiliary support structures include an auxiliary support structure that supports the middle portion of the first capacitor 210 in its extension direction. In the above embodiment, the first auxiliary support structure 521 can be used to further improve the stability of the first capacitor 210, thereby helping to prevent the first capacitor 210 from collapsing.

[0082] In some optional implementations, a portion of the plurality of auxiliary support structures are supported on sidewalls of the second capacitor 310. Exemplarily, the plurality of auxiliary support structures include a fourth auxiliary support structure, the second capacitor 310 extends through the fourth auxiliary support structure, and the second capacitor 310 at both ends of its extension direction at least partially extends beyond the fourth auxiliary support structure.

[0083] In some optional embodiments, the plurality of auxiliary support structures include an auxiliary support structure that supports the middle portion of the second capacitor 310 in its extension direction. In the above embodiment, the fourth auxiliary support structure can be used to further improve the stability of the second capacitor 310, thereby helping to prevent the second capacitor 310 from collapsing.

[0084] In some optional embodiments, along the direction from the first capacitor unit 200 to the second capacitor unit 300 , a plurality of auxiliary support structures are arranged at intervals in the first capacitor unit 200 and supported between adjacent first electrodes 211 .

[0085] Reference Figure 15 In some optional embodiments, the auxiliary support structure provided in the first capacitor unit 200 may be a first auxiliary support structure 521. The first auxiliary support structure 521 may provide support for the first capacitor 210 in the first capacitor unit 200, thereby improving the structural stability and reliability of the first capacitor unit 200.

[0086] In some optional embodiments, in the first capacitor unit 200, multiple layers of first auxiliary support structures 521 are provided along the extension direction of the first capacitor 210. Specifically, the number of layers of the first auxiliary support structures 521 can be set according to the height of the first capacitor 210, and the embodiments of the present disclosure do not limit the specific value of the number of layers.

[0087] In some optional embodiments, a plurality of auxiliary support structures are spaced apart in the second capacitor unit 300 and supported between adjacent third electrodes 311 to improve the stability of each second capacitor 310 in the second capacitor unit 300. In some further optional embodiments, at least some of the auxiliary support structures are supported on an end of the third electrode 311 away from the first capacitor unit 200.

[0088] Reference Figure 15 In some optional embodiments, the auxiliary support structure supporting the end of the third electrode 311 away from the first capacitor unit 200 is a third auxiliary support structure 621. Optionally, the third auxiliary support structure 621 has a mounting groove, and the end of the third electrode 311 of the second capacitor 310 away from the first capacitor unit 200 is at least partially located in the mounting groove. The third auxiliary support structure 621 provides support for the third electrode 311 in the second capacitor unit 300, thereby improving the structural stability and reliability of the second capacitor unit 300.

[0089] On the other hand, the embodiments of the present disclosure further provide a method for preparing a capacitor structure, which can be applied to prepare the above-mentioned capacitor structure.

[0090] Reference Figure 20In some optional embodiments, the method for preparing the capacitor structure may include the following steps:

[0091] Step S01: Provide a base layer. The base layer 100 is a basic structural component that can provide a mounting base for the first capacitor unit 200. Figure 1 In some optional embodiments, when the capacitor structure is applied to a memory, it may include a substrate 110, a transistor structure, a word line, and a bit line 120, wherein the transistor structure, the word line, and the bit line 120 are all disposed in the substrate 110. The substrate 110 may be formed into a plurality of active regions 111 by doping, and shallow trench isolation (STI) 150 is disposed between adjacent active regions 111 to prevent electrical interference between adjacent active regions 111.

[0092] refer to Figure 1 and Figure 15 , a plurality of bit lines 120 extending along the second direction and spaced apart are formed in the base layer 100, as well as a plurality of word lines (not shown) extending along the third direction and spaced apart are formed. The second direction and the third direction have an angle. For example, the second direction and the third direction can be perpendicular to each other, wherein the third direction can be Figure 15 The second direction can be perpendicular to Figure 15 The direction indicated by the x-axis and the direction indicated by the z-axis.

[0093] In some optional embodiments, the word line may be a buried word line. For example, along a direction perpendicular to the base layer 100 ( Figure 15 The word line is located below the bit line 120, that is, the word line is located deeper in the base layer 100 than the bit line 120. Figures 1 to 15 is a cross-sectional view of the capacitor structure perpendicular to the extending direction of the bit line 120 .

[0094] Multiple capacitor plugs 130 are spaced apart between adjacent bit lines 120, and each capacitor plug 130 is insulated from another. A contact pad 140 is disposed at one end of each capacitor plug 130. The contact pad 140 is exposed on the surface of the substrate 100 to facilitate contact with the capacitor structure and achieve electrical connection. The capacitor plug 130 can be made of polysilicon, and the contact pad 140 can be made of tungsten.

[0095] Step S03: forming a first capacitor unit, where the first capacitor unit is located on the base layer and includes a plurality of first capacitors arranged in an array.

[0096] In some optional embodiments, the source of the transistor structure is connected to the bit line 120, the gate of the transistor structure is connected to the word line, and the drain of the transistor structure is connected to the electrode of the first capacitor unit 200 of the capacitor structure.

[0097] like Figure 1 As shown, the cross-section of the contact pad 140, taken along a surface perpendicular to the extending direction of the bit line 120, can be roughly Z-shaped. This arrangement allows the size of the surface of the contact pad 140 at the end connected to the capacitor structure to be adjusted so that the area of ​​the surface is larger than the area of ​​the contact surface between the contact pad 140 and the capacitor plug 130. That is, the area of ​​the top surface of the contact pad 140 is larger than the area of ​​the bottom surface of the contact pad 140, thereby facilitating the formation of a capacitor structure on the base layer 100.

[0098] refer to Figure 15 The capacitor structure is formed on the base layer 100. For example, one first capacitor 210 in the first capacitor unit 200 corresponds to one contact pad 140. Furthermore, optionally, one electrode of the first capacitor 210 is in direct contact with and electrically connected to the corresponding contact pad 140. In this way, the corresponding capacitor structure can be discharged or charged through the transistor structure, thereby achieving data storage.

[0099] Step S05: Forming a support layer, which is located on the first capacitor unit and includes a plurality of support structures arranged in an array. The support layer 400 can provide a mounting base for the second capacitor unit 300, thereby preparing for the second capacitor unit 300 to be superimposed on the first capacitor unit 200.

[0100] Step S07: forming a second capacitor unit, the second capacitor unit being located on the support layer, the second capacitor unit including a plurality of second capacitors arranged in an array, an electrode of a first capacitor being connected to an electrode of a second capacitor correspondingly. The support structure is located between the first capacitor and the second capacitor, and the cross-sectional area of ​​the electrode of the first capacitor close to the support structure is larger than the cross-sectional area of ​​the electrode of the second capacitor close to the support structure. Exemplarily, the support structure 410 has a mounting groove so that at least a portion of the second capacitor 310 in the second capacitor unit 300 can pass through the mounting groove through the support structure 410 and be connected to the corresponding first capacitor 210.

[0101] In the above-mentioned method for preparing the capacitor structure, a second capacitor unit 300 is further prepared on the basis of the first capacitor unit 200 so that the second capacitor unit 300 is connected to the first capacitor unit 200, thereby improving the aspect ratio of the capacitor structure and making the capacitor structure have a larger storage capacity.

[0102] In addition, the cross-sectional area of ​​the electrode of the second capacitor 310 on the side closest to the support structure 410 is reduced, so that the cross-sectional area of ​​the electrode of the second capacitor 310 on the side closest to the support structure 410 is smaller than the cross-sectional area of ​​the electrode of the first capacitor 210 on the side closest to the support structure 410. Therefore, during the preparation of the second capacitor unit 300, not only is the difficulty of aligning the electrode of the second capacitor 310 with the electrode of the first capacitor 210 reduced, but it is also beneficial to prevent the electrode of the second capacitor 310 from being simultaneously conductively connected to the same electrode of two first capacitors 210, thereby improving the product yield and reliability.

[0103] In some optional embodiments, step S05, forming a support layer, may include the following sub-steps:

[0104] Step S051: forming a support material layer, where the support material layer is located on the first capacitor unit.

[0105] Reference Figure 5 and Figure 6 In some optional embodiments, after forming the first capacitor unit 200, a support material layer 401 may be formed on the surface of the first capacitor unit 200 facing away from the base layer 100. In some optional embodiments, before forming the support material layer 401, the surface of the first capacitor unit 200 facing away from the base layer 100 may be processed so that the electrode of the first capacitor unit 200 is exposed on the surface of the first capacitor unit 200 facing away from the base layer 100. That is, the end surface of the electrode of the first capacitor unit 200 facing away from the base layer 100 abuts against the support material layer 401, preparing for electrical connection between the electrode of the second capacitor 310 and the electrode of the first capacitor unit 200.

[0106] In some optional embodiments, a support material layer 401 may be formed on a side of the first capacitor unit 200 facing away from the base layer 100 by a deposition process. For example, the deposition process may be, but is not limited to, chemical vapor deposition (CVD), physical vapor deposition (PVD), or atomic layer deposition (ALD).

[0107] In a further optional embodiment, the material of the support material layer 401 may be silicon boron nitride. In a further optional embodiment, the molecular weight ratio of boron to nitrogen in the support material layer 401 is 1:3.

[0108] Step S053: Etching the support material layer to form a plurality of support structures arranged in an array, wherein the plurality of support structures form a support layer. Figure 7 and Figure 8In some optional embodiments, a plurality of support structures 410 can be formed on the support material layer 401 through an etching process. In an optional embodiment, one support structure 410 corresponds to one first capacitor 210. Further optionally, each support structure 410 has a mounting groove, and each mounting groove is opposite to an electrode of a first capacitor 210, so that the electrode of the second capacitor 310 on the support layer 400 is connected to the electrode of the first capacitor 210 through the mounting groove.

[0109] Reference Figure 8 and Figure 10 In some optional embodiments, the sidewalls of the support structure 410 are inclined. Furthermore, optionally, the cross-sectional area of ​​the support structure 410 on the side closest to the first capacitor unit 200 is greater than the cross-sectional area of ​​the support structure 410 on the side closest to the second capacitor unit 300. The cross-sectional area of ​​the support structure 410 is the area of ​​the cross section perpendicular to the direction from the first capacitor unit 200 to the second capacitor unit 300.

[0110] For example, a plurality of holes or trenches for accommodating the electrodes of the second capacitor 310 can be formed on the support material layer 401 by an etching process. Furthermore, the inner sidewalls of the holes or trenches for accommodating the electrodes of the second capacitor 310 are inclined. Further optionally, the cross-sectional area of ​​the holes or trenches for accommodating the electrodes of the second capacitor 310 gradually decreases from the side away from the first capacitor unit 200 to the side close to the first capacitor unit 200, thereby making the cross-sectional area of ​​the side of the support structure 410 close to the first capacitor unit 200 larger than the cross-sectional area of ​​the side of the support structure 410 close to the second capacitor unit 300. The cross-sectional area of ​​the holes or trenches for accommodating the electrodes of the second capacitor 310 is the area of ​​the cross section along the direction perpendicular to the first capacitor unit 200 to the second capacitor unit 300.

[0111] In the above embodiment, the support layer 400 is formed by the support material layer 401, and the support structure 410 of the support layer 400 provides a support base for the third electrode 311 of the second capacitor 310. In this embodiment, the sidewalls of the support structure 410 are inclined, which helps to reduce the difficulty of aligning the trench in the support structure 410 that accommodates the electrode of the second capacitor 310 with the first electrode 211 of the first capacitor 210, thereby reducing the difficulty of manufacturing the capacitor structure.

[0112] In some optional embodiments, step S03, forming the first capacitor unit, may include the following sub-steps:

[0113] Step S031: forming a first dielectric layer. Figure 2 In some optional embodiments, the first dielectric layer 500 may be formed by a deposition process. For example, the first dielectric layer 500 is stacked on a side of the base layer 100 having the contact pad 140 .

[0114] Step S033: etching the first dielectric layer to form a plurality of first channels arranged in an array. Figure 3 The first trench 501 is opposite to the contact pad 140 in the base layer 100, so that the end surface of the contact pad 140 away from the capacitor plug 130 is exposed through the first trench 501. In this way, preparations can be made for forming the first electrode 211 so that the first electrode 211 can be electrically connected to the contact pad 140 in the base layer 100.

[0115] For example, the portion of the first dielectric layer 500 opposite to the contact pad 140 may be removed by dry etching with a chlorine-based gas to form a Figure 3 A first channel 501 is shown.

[0116] Step S035: forming a first conductive layer, the first conductive layer filling the first trench, the first conductive layer forming the first electrode of the first capacitor unit. Figure 4 In some optional embodiments, the first conductive layer 201 may be filled in the first trench 501 through a deposition process, so that the first conductive layer 201 may be used to form the first electrode 211 .

[0117] In some optional embodiments, the first conductive layer 201 fills the first channel 501. Further optionally, the first conductive layer 201 covers the surface of the first dielectric layer 500 facing away from the base layer 100, thereby ensuring that the first conductive layer 201 can fill the first channel 501.

[0118] Reference Figure 4 and Figure 5 In some optional embodiments, step S03 of forming the first capacitor unit further includes the following sub-steps:

[0119] Step S037: removing a portion of the first conductive layer located on a side of the first dielectric layer away from the base layer, and exposing a surface of the first dielectric layer away from the base layer, to form a plurality of first electrodes arranged in an array.

[0120] In a further optional embodiment, the surface of the first conductive layer 201 in the first channel 501 facing away from the base layer 100 is flush with the surface of the first dielectric layer 500 facing away from the base layer 100, so as to prepare for forming the support layer 400 and the second capacitor unit 300.

[0121] Reference Figure 5 and Figure 6 In some optional implementations, step S051 is after step S037. Figure 6 As shown, the support material layer 401 covers the surface of the first dielectric layer 500 facing away from the base layer 100 and the surface of the first conductive layer 201 facing away from the base layer 100 .

[0122] Reference Figure 7 and Figure 8 In some optional embodiments, step S07, the second capacitor unit, may include the following sub-steps: Step S071: forming a second dielectric layer. Figure 6 and Figure 7 In some optional embodiments, the second dielectric layer 600 may be formed by a deposition process. Figure 7 , step S071 , forming the second dielectric layer 600 may be before step S053 , etching the support material layer 401 .

[0123] Illustratively, a support material layer 401 is first formed on the side of the first capacitor unit 200 facing away from the base layer 100, and then a second dielectric layer 600 is formed on the side of the support material layer 401 facing away from the base layer 100, so that the second dielectric layer 600 is stacked on the side of the support material layer 401 facing away from the first dielectric layer 500.

[0124] Step S073: Etching the second dielectric layer and the supporting material layer to form a plurality of second channels arranged in an array, wherein one second channel is connected to one first channel. Figure 8 In some optional embodiments, a second trench 601 is opposite to a first trench 501. Furthermore, optionally, the second trench 601 penetrates the second dielectric layer 600 and the support material layer 401 to expose the surface of the first conductive layer 201 in the first trench 501 on the side facing away from the base layer 100. The second trench 601 can prepare for the formation of the third electrode 311 and facilitate electrical connection between the third electrode 311 and the first electrode 211 in the first trench 501.

[0125] In a further optional embodiment, the cross-sectional area of ​​the portion of the second channel 601 that passes through the support material layer 401 gradually decreases from the second dielectric layer 600 to the first dielectric layer 500. This helps ensure that one second channel 601 is connected to one first channel 501, thereby reducing the difficulty of aligning the second channel 601 with the first channel 501.

[0126] Step S075 : forming a second conductive layer, which fills the second trench and is connected to the first conductive layer in the corresponding first trench. The second conductive layer forms the third electrode of the second capacitor unit 300 .

[0127] Reference Figure 9 In some optional embodiments, the second conductive layer 301 may be filled in the second trench 601 by a deposition process, so that the second conductive layer 301 may be used to form the third electrode 311. Figure 8 and Figure 9, the second conductive layer 301 fills the second channel 601, so that the second conductive layer 301 can be used to form the third electrode 311. Further, optionally, the second conductive layer 301 covers the surface of the second dielectric layer 600 facing away from the support material layer 401, thereby ensuring that the second conductive layer 301 can fill the second channel 601. One second channel 601 is connected to one first channel 501. Therefore, this embodiment is beneficial in ensuring that one third electrode 311 is electrically connected to one first electrode 211.

[0128] Reference Figure 9 and Figure 12 In some optional embodiments, step S07, the second capacitor unit, may further include:

[0129] Step S077 , removing a portion of the second conductive layer located on a side of the second dielectric layer away from the support material layer, and exposing a surface of the second dielectric layer away from the support material layer to form a plurality of third electrodes arranged in an array.

[0130] Reference Figure 2 In some optional embodiments, the first dielectric layer 500 includes a first sub-dielectric layer 510 , a first auxiliary support material layer 520 , a second sub-dielectric layer 530 and a second auxiliary support material layer 540 stacked in sequence in a direction away from the base layer 100 .

[0131] Exemplarily, step S031, forming a first dielectric layer, may include the following sub-steps:

[0132] Step S0311 , forming a first sub-dielectric layer on the base layer.

[0133] Step S0313: forming a first auxiliary supporting material layer on a side of the first sub-dielectric layer facing away from the base layer.

[0134] Step S0315 : forming a second sub-dielectric layer on a side of the first auxiliary supporting material layer away from the first sub-dielectric layer.

[0135] Step S0317 : forming a second auxiliary supporting material layer on a surface of the second sub-dielectric layer on a side facing away from the first auxiliary supporting material layer.

[0136] For example, the material of the first sub-dielectric layer 510 and the material of the second sub-dielectric layer 530 may be the same. The material of the first auxiliary supporting material layer 520 and the material of the second auxiliary supporting material layer 540 may be the same.

[0137] Reference Figure 3 In some optional embodiments, step S033, etching the first dielectric layer, may include the following sub-steps:

[0138] Step S0331: Etching the first sub-dielectric layer, the first auxiliary support material layer, the second sub-dielectric layer and the second auxiliary support material layer. The etched first auxiliary support material layer forms a first auxiliary support structure, and the etched second auxiliary support material layer forms a second auxiliary support structure, which abuts against the support structure.

[0139] Reference Figure 3 After etching, the first sub-dielectric layer 510, the first auxiliary support material layer 520, the second sub-dielectric layer 530 and the second auxiliary support material layer 540 all form corresponding groove structures, and the corresponding groove structures are interconnected to prepare for the subsequent formation of the first electrode 211.

[0140] Reference Figure 7 The second dielectric layer 600 includes a third sub-dielectric layer 610 and a third auxiliary supporting material layer 620 stacked in a direction away from the base layer 100 .

[0141] In some optional embodiments, step S071, forming a second dielectric layer, includes the following sub-steps:

[0142] Step S0711: forming a third sub-dielectric layer on a surface of the supporting material layer facing away from the first dielectric layer.

[0143] Step S0712: forming a third auxiliary supporting material layer on a surface of the third sub-dielectric layer facing away from the supporting material layer.

[0144] In some optional embodiments, step S073, etching the second dielectric layer, includes the following sub-steps:

[0145] Step S0731: etching the third sub-dielectric layer and the third auxiliary support material layer, and the etched third auxiliary support material layer forms a third auxiliary support structure.

[0146] Reference Figure 8 , a channel structure can be formed by etching the third sub-dielectric layer 610 and the third auxiliary support material layer 620. Further optionally, the channel structures on the third sub-dielectric layer 610 and the third auxiliary support material layer 620 correspond to and are connected to the channel structures of the support material layer 401.

[0147] Reference Figure 7 and Figure 8 In some optional embodiments, a support material layer 401 and a second dielectric layer 600 can be first formed on the surface of the first capacitor unit 200 facing away from the base layer 100, and then the second dielectric layer 600 and the support material layer 401 are etched to form a second channel 601 penetrating the second dielectric layer 600 and the support material layer 401.

[0148] In some optional implementations, after forming the second conductive layer in step S075, the method for preparing the capacitor structure further includes the following steps:

[0149] Step S0751: removing the first sub-dielectric layer, the second sub-dielectric layer and the third sub-dielectric layer to form a third trench, wherein the third trench exposes part of the sidewalls of the first electrode and the third electrode.

[0150] For example, Figure 13 and Figure 14 As shown, the third sub-dielectric layer 610 , the second sub-dielectric layer 530 and the first sub-dielectric layer 510 may be removed in sequence through an etching process.

[0151] Step S0753: forming a capacitor dielectric layer, the capacitor dielectric layer covers the exposed sidewalls of the first electrode and the third electrode, and forming a fourth channel in the capacitor dielectric layer.

[0152] For example, a capacitor dielectric layer may be formed by deposition on part of the sidewalls of the first electrode 211 and the third electrode 311. The thickness of the capacitor dielectric layer is less than half the width of the third channel 502, so that the fourth channel can be formed in the capacitor dielectric layer.

[0153] Step S0755: Form a third conductive layer, which fills the fourth trench. The capacitor dielectric layer covering the first electrode forms the first capacitor dielectric layer, the capacitor dielectric layer covering the third electrode forms the second capacitor dielectric layer, the third conductive layer abutting the first capacitor dielectric layer forms the second electrode of the first capacitor unit, and the third conductive layer abutting the second capacitor dielectric layer forms the fourth electrode of the second capacitor unit. In an optional embodiment, the third conductive layer fills the fourth trench to form the second electrode 212 and the fourth electrode 312, which is beneficial for improving the stability of the capacitor structure.

[0154] In some optional embodiments, such as Figure 12 and Figure 13 As shown, removing the third sub-dielectric layer 610 includes the following steps:

[0155] Step S07511: opening a hole in the third auxiliary supporting material layer to expose at least a portion of the surface of the third sub-dielectric layer on a side facing away from the supporting layer.

[0156] In this step, a through hole can be formed on the third auxiliary supporting material layer 620 , so that the acid used to etch the third sub-dielectric layer 610 can enter through the through hole and etch the third sub-dielectric layer 610 to remove the third sub-dielectric layer 610 .

[0157] Step S07513: removing the third sub-dielectric layer.

[0158] Exemplarily, the third sub-dielectric layer may be removed by an etching process.

[0159] In some optional embodiments, a hole can be opened in the third auxiliary support material layer 620 through an etching process. For example, the third auxiliary support material layer 620 can be etched using a CF4 / CHF3 / O2-based gas to form a through hole penetrating the third auxiliary support material layer 620. Further, optionally, the third sub-dielectric layer 610 can be etched using a C4F6 / O2-based gas to remove the third sub-dielectric layer 610.

[0160] In some optional embodiments, referring to Figure 12 and Figure 13 , removing the second sub-dielectric layer and the first sub-dielectric layer includes the following steps:

[0161] Step S07515: opening holes in the support layer and the second auxiliary support material layer to expose at least a portion of the surface of the second sub-dielectric layer facing away from the first auxiliary support material layer and away from the first sub-dielectric layer.

[0162] In this way, a through hole can be formed on the second auxiliary supporting material layer 540 , so that the acid used to etch the second sub-dielectric layer 530 can enter through the through hole and etch the second sub-dielectric layer 530 to remove the second sub-dielectric layer 530 .

[0163] For example, the support layer 400 may be etched using C4F6 / O2 in combination with some CF4-based gases to form a through hole penetrating the support layer 400. For example, the second auxiliary support material layer 540 may be etched using CF4 / CHF3 / O2-based gases to form a through hole penetrating the second auxiliary support material layer 540, thereby exposing at least a portion of the surface of the second sub-dielectric layer 530.

[0164] Step S07517: removing the second sub-dielectric layer. For example, a C4F6 / O2-based gas may be used to etch the second sub-dielectric layer 530 to remove the second sub-dielectric layer 530.

[0165] Step S07518: opening a hole in the first auxiliary supporting material layer to expose at least a portion of the surface of the first sub-dielectric layer facing away from the base layer.

[0166] In this way, a through hole can be formed in the first auxiliary support material layer 520, so that the acid used to etch the first sub-dielectric layer 510 can enter through the through hole and etch the first sub-dielectric layer 510 to remove the first sub-dielectric layer 510. For example, the first auxiliary support material layer 520 can be etched using a CF4 / CHF3 / O2-based gas to form a through hole penetrating the first auxiliary support material layer 520, thereby exposing at least a portion of the surface of the first sub-dielectric layer 510.

[0167] Step S07519: removing the first sub-dielectric layer. For example, a C4F6 / O2-based gas may be used to etch the first sub-dielectric layer 510 to remove the first sub-dielectric layer 510.

[0168] In some optional examples, the materials of the first auxiliary support material layer 520 , the second auxiliary support material layer 540 and the third auxiliary support material layer 620 may be silicon nitride, silicon oxide or silicon oxynitride.

[0169] In some optional embodiments, the first sub-dielectric layer 510, the second sub-dielectric layer 530, and the third sub-dielectric layer 610 can be made of borophospho-silicate glass (BPSG) or a silicon dioxide layer deposited by a HDP-CVD (high-density plasma chemical vapor deposition) process. Of course, the first sub-dielectric layer 510, the second sub-dielectric layer 530, and the third sub-dielectric layer 610 can also be made of polysilicon, photoresist, metal film, polyimide, etc.

[0170] In some optional embodiments, the first capacitor dielectric layer 213 and the second capacitor dielectric layer 313 are made of insulating materials. For example, the first capacitor dielectric layer 213 and the second capacitor dielectric layer 313 may be made of hafnium oxide, zirconium oxide, calcium titanate, or barium titanate.

[0171] In some optional embodiments, the first electrode 211 , the second electrode 212 , the third electrode 311 and the fourth electrode 312 may be made of titanium nitride, molybdenum nitride, ruthenium nitride, germanium-doped polysilicon or alloys thereof.

[0172] On the other hand, embodiments of the present disclosure further provide a memory. The memory includes a base layer 100 and the capacitor structure provided in the above embodiments, wherein the capacitor structure is disposed on the base layer 100. The base layer 100 includes a substrate 110, a transistor structure, a word line, and a bit line 120, wherein the transistor structure, the word line, and the bit line 120 are all disposed in the substrate 110; the source of the transistor structure is connected to the bit line 120, the gate of the transistor structure is connected to the word line, and the drain of the transistor structure is connected to the corresponding electrode of the first capacitor unit 200 of the capacitor structure.

[0173] The memory provided in the above embodiment includes the same structure as the capacitor structure described above. Therefore, the memory provided in the present disclosure has the same or corresponding technical effects as the above capacitor structure, which will not be described in detail here. In addition, in the above embodiment, the capacitor structure has a larger storage capacity.

[0174] In some optional embodiments, the drain of a transistor structure is connected to the electrode of a first capacitor 210, so that a transistor structure can transmit a signal to the electrode corresponding to the first capacitor 210 and the electrode of the second capacitor 310 correspondingly connected to the first capacitor 210, thereby completing the storage and reading of multiple stacked capacitor units.

[0175] In the present disclosure, each embodiment or implementation method is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referenced to each other. In the description of the present disclosure, the description of the reference terms "one embodiment", "some embodiments", "illustrative embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the present disclosure, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0176] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A capacitor structure, characterized in that: The invention comprises a first capacitor unit and a second capacitor unit arranged in a stacked manner, wherein the second capacitor unit is stacked on top of the first capacitor unit; the first capacitor unit comprises a plurality of first capacitors arranged in an array, the first capacitor comprises a first electrode and a second electrode, and a first capacitor dielectric layer is provided between the first electrode and the second electrode; the second capacitor unit comprises a plurality of second capacitors arranged in an array, the second capacitor comprises a third electrode and a fourth electrode, and a second capacitor dielectric layer is provided between the third electrode and the fourth electrode; the first electrode and the third electrode are connected correspondingly, and the second electrode and the fourth electrode are connected correspondingly; A support layer is provided between the first capacitor unit and the second capacitor unit, the support layer comprising a plurality of support structures arranged in an array, the support structures being located between the corresponding second electrode and the fourth electrode; The cross-sectional area of ​​the side of the electrode of the first capacitor close to the support structure is larger than the cross-sectional area of ​​the side of the electrode of the second capacitor close to the support structure; And / or, the capacitor structure further includes a plurality of auxiliary support structures, at least some of the auxiliary support structures are located between the corresponding second electrode and the fourth electrode, and abut against a side of the support structure close to the second electrode.

2. The capacitor structure according to claim 1, wherein: The electrode of the second capacitor includes a first extension segment and a second extension segment connected to each other, the first extension segment is close to the support structure, and the second extension segment is far away from the support structure; The cross-sectional area of ​​at least part of the first extension segment is smaller than the cross-sectional area of ​​the corresponding electrode of the first capacitor, and the cross-sectional area of ​​at least part of the first extension segment is smaller than the cross-sectional area of ​​the second extension segment.

3. The capacitor structure according to claim 2, wherein: The cross-sectional area of ​​the first extension section gradually increases in a direction away from the support structure; The cross-sectional area of ​​one end of the first extension section connected to the second extension section is the same as the cross-sectional area of ​​the second extension section; And / or, the cross-sectional area of ​​the second extension segment is equal to the cross-sectional area of ​​the corresponding electrode of the first capacitor.

4. The capacitor structure according to claim 1, wherein: The side walls of the support structure are arranged at an angle, and the cross-sectional area of ​​the support structure on the side close to the first capacitor unit is larger than the cross-sectional area of ​​the support structure on the side close to the second capacitor unit; the cross-sectional area of ​​the support structure is the area of ​​the cross section along the direction perpendicular to the first capacitor unit to the second capacitor unit.

5. The capacitor structure according to claim 4, characterized in that: Along the direction from the first capacitor unit to the second capacitor unit, the cross-sectional area of ​​the support structure gradually decreases; And / or, the angle between the side wall of the support structure and the preset plane is in the range of 70°-80°, and the extension direction of the preset plane is perpendicular to the direction from the first capacitor unit to the second capacitor unit.

6. The capacitor structure according to any one of claims 1 to 5, characterized in that: The material of the support structure is silicon boron nitride, wherein the molecular weight ratio of boron to nitrogen is 1:

3.

7. A method for preparing a capacitor structure, characterized in that: include: Provide grassroots; forming a first capacitor unit, where the first capacitor unit is located on the base layer and includes a plurality of first capacitors arranged in an array; forming a support material layer, wherein the support material layer is located on the first capacitor unit; Etching the support material layer to form a plurality of support structures arranged in an array, wherein the plurality of support structures form a support layer; forming a second capacitor unit, the second capacitor unit being located on the supporting layer, the second capacitor unit comprising a plurality of second capacitors arranged in an array, an electrode of the first capacitor being connected to an electrode of the second capacitor correspondingly; In which, the support structure is located between the first capacitor and the second capacitor, the side wall of the support structure is inclined, and the cross-sectional area of ​​the support structure close to the first capacitor unit is larger than the cross-sectional area of ​​the support structure close to the second capacitor unit; the cross-sectional area of ​​the support structure is the area of ​​the cross section along the direction perpendicular to the first capacitor unit to the second capacitor unit.

8. A memory, characterized in that: include: A base layer and a capacitor structure according to any one of claims 1 to 6, wherein the capacitor structure is arranged on the base layer; The base layer includes a substrate, a transistor structure, a word line and a bit line, and the transistor structure, the word line and the bit line are all arranged in the substrate; the source of the transistor structure is connected to the bit line, the gate of the transistor structure is connected to the word line, and the drain of the transistor structure is correspondingly connected to the electrode of the first capacitor unit of the capacitor structure.

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