Gyroscope type deep trench structure silicon capacitor and preparation method thereof

Abstract

The present application relates to a kind of gyro type deep groove structure silicon capacitors and its preparation method, including the array arrangement of multiple gyro type silicon columns, wherein gyro type silicon column center includes a regular hexagonal silicon column, three sides of which are not adjacent respectively connected with the side of other three identical regular hexagonal silicon column through a connecting structure, the same column gyro type silicon column is placed in the same direction, the direction of adjacent two columns gyro type silicon column is opposite, and multiple columns gyro type silicon column is staggered and embedded.The gyro type deep groove structure silicon capacitor of the present application can significantly improve specific surface area and structural stability while ensuring the flowability of deep groove gas, can support higher aspect ratio deep groove structure silicon capacitor, and further improve the capacitance density.

Description

Technical Field

[0001] This application relates to the field of silicon capacitor technology, and in particular to a gyroscope-type deep trench silicon capacitor and its fabrication method. Background Technology

[0002] Existing silicon capacitors based on riveted deep trench structures improve the overall mechanical stability of silicon capacitors without sacrificing the specific surface area of ​​the deep trench structure, thereby supporting the fabrication of silicon capacitors with higher aspect ratios and enabling silicon capacitors to achieve higher capacitance density.

[0003] However, existing silicon capacitors based on riveted deep trench structures mostly have orthogonal elongated riveted deep trench structures, which have limited improvement in relative surface area and a single stress dispersion and transmission path. In actual working conditions, when subjected to large global stresses from multiple directions including external and internal factors, their stress dispersion ability is weak, and the local stress peak is high, resulting in insufficient mechanical stability in actual production. In addition, silicon capacitors with riveted deep trench structures are mostly fabricated using dry etching, which is costly and introduces higher stress during fabrication, severely limiting the aspect ratio of silicon capacitors in actual production. This makes mass production of existing silicon capacitors based on riveted deep trench structures difficult and has limited improvement in capacitance density. Summary of the Invention

[0004] To overcome the technical problems of insufficient specific surface area and stability of silicon capacitors with riveted deep trench structures in the prior art, this invention provides a gyroscope-type deep trench structure silicon capacitor and its preparation method.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A gyroscope-type deep trench silicon capacitor includes: Substrate; Multiple gyroscope-shaped silicon pillars are arranged in an array perpendicular to the upper surface of the substrate, wherein: Multiple gyroscope-shaped silicon pillars are arranged at equal intervals along the vertical direction of the upper surface of the substrate; Along the horizontal direction of the upper surface of the substrate, with the center of the gyro-shaped silicon pillar as the axis, multiple gyro-shaped silicon pillars are rotated by an angle α in sequence and then arranged at equal intervals, with the centers of the multiple gyro-shaped silicon pillars located on the same horizontal straight line; The gaps between the plurality of gyro-shaped silicon pillars form deep grooves; A lower electrode layer, a dielectric layer, and an upper electrode layer are sequentially deposited on the substrate, multiple gyro-shaped silicon pillars, and a deep trench; Each of the aforementioned gyroscope-shaped silicon pillars has the same structure, including a first regular hexagonal silicon pillar, a second regular hexagonal silicon pillar, a third regular hexagonal silicon pillar, a fourth regular hexagonal silicon pillar, and three connecting structures. The three non-adjacent sides of the first regular hexagonal silicon pillar are respectively connected to one side of the second, third, and fourth regular hexagonal silicon pillars through one of the connecting structures.

[0006] Preferably, the width of the deep groove is less than the side length of the regular hexagon on the upper surface of the first regular hexagonal silicon pillar.

[0007] Preferably, the first, second, third, and fourth regular hexagonal silicon pillars are all the same size.

[0008] Preferably, the angle α = n × 60°, where n is an odd number.

[0009] Preferably, the connecting structure is a cuboid or a cube; The length of the connecting structure is the same as the side length of the regular hexagon on the upper surface of the first regular hexagonal silicon pillar; The height of the connecting structure is the same as the height of the first regular hexagonal silicon pillar.

[0010] A method for fabricating a gyroscope-type deep trench silicon capacitor includes the following steps: S1: Photolithography is performed on the silicon substrate to form a silicon substrate covered with a photoresist gyroscope pattern array; S2: Deposit a gold film on a silicon substrate covered with a photoresist gyroscope pattern array, and then remove the photoresist gyroscope pattern array to obtain a silicon substrate with a recessed gyroscope pattern array without photoresist. S3: The silicon substrate with the recessed gyroscope-shaped pattern array without photoresist is sequentially etched and post-processed to obtain a gyroscope-shaped deep trench structure; S4: Sequentially deposit the lower electrode layer, the dielectric layer, and the upper electrode layer on the gyro-shaped deep trench structure to obtain a silicon capacitor with a gyro-shaped deep trench structure.

[0011] Preferably, in step S1, the photolithography process includes: Positive photoresist is uniformly spin-coated onto a silicon substrate, followed by exposure and development. The surface of the silicon substrate is then treated in an oxygen plasma environment to obtain a silicon substrate covered with a photoresist gyroscope pattern array.

[0012] Preferably, in step S2, the thickness of the gold film is less than the thickness of the photoresist, and the thickness is 18~25 nanometers.

[0013] Preferably, in step S3, the etching process includes: The photoresist-free recessed gyroscope-patterned silicon substrate is completely immersed in an etching solution. On the upper surface of the photoresist-free recessed gyroscope-patterned silicon substrate, the photoresist in the gyroscope-patterned array region and the gold film on the photoresist are removed, while the remaining regions are covered with a gold film. In the regions covered with the gold film, gold-catalyzed etching of silicon is performed under the action of the etching solution, which includes hydrofluoric acid, ethanol, hydrogen peroxide, and deionized water.

[0014] Preferably, in step S3, the post-processing includes: removing the gold from the bottom of the gyroscope-shaped deep groove using a mixed solution of iodine and potassium iodide, and cleaning and drying the gyroscope-shaped deep groove structure.

[0015] Compared with the prior art, the beneficial effects of the technical solution of the present invention are: This invention provides a gyro-shaped deep trench silicon capacitor, comprising multiple gyro-shaped silicon pillars arranged in an array, which significantly expands the specific surface area of ​​the deep trench structure, thereby achieving a significant increase in capacitance density. Secondly, the gyro-shaped silicon pillars of this invention consist of four regular hexagonal silicon pillars and three connecting structures, greatly improving the stability of the structure and enabling it to withstand greater mechanical stress. This allows the silicon capacitor using the gyro-shaped deep trench structure to maintain good stability at higher aspect ratios, supporting the fabrication of large-capacity deep trench silicon capacitors with higher aspect ratios. Furthermore, the gyro-shaped deep trench structure fabrication method provided by this invention uses gold-catalyzed etching, which significantly reduces manufacturing costs and, combined with the gyro-shaped deep trench structure provided by this invention, can achieve even higher aspect ratios. Attached Figure Description

[0016] Figure 1 This is one of the top view structural diagrams of a gyroscope-type deep trench structure silicon capacitor in Example 1; Figure 2 This is a cross-sectional schematic diagram of a gyro-type deep trench silicon capacitor in Example 1; Figure 3 This is a stress distribution diagram of a gyro-type deep trench silicon capacitor in Example 2; Figure 4 This is the second top view of a gyroscope-type deep trench silicon capacitor in Example 2; Figure 5 This is a schematic diagram of the dimensional parameters of the incomplete gyro-shaped silicon pillar structure of a gyro-shaped deep trench silicon capacitor in Example 2; Figure 6 This is a flowchart of a method for fabricating a gyroscope-type deep trench silicon capacitor in Example 3.

[0017] In the figure, 1-substrate; 2-gyro-shaped silicon pillar; 3-deep trench; 4-lower electrode layer; 5-dielectric layer; 6-upper electrode layer; 21-first regular hexagonal silicon pillar; 22-second regular hexagonal silicon pillar; 23-third regular hexagonal silicon pillar; 24-fourth regular hexagonal silicon pillar; 25-connection structure. Detailed Implementation

[0018] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this application. To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Example 1 Figure 1 A top view of the gyro-type deep trench structure silicon capacitor in this embodiment is shown; This embodiment provides a gyroscope-type deep trench silicon capacitor, including: Substrate 1; In this embodiment, substrate 1 is made of silicon; Multiple gyroscope-shaped silicon pillars 2 are arranged in an array perpendicular to the upper surface of the substrate 1; Each of the gyroscope-shaped silicon pillars 2 has the same structure, including a first regular hexagonal silicon pillar 21, a second regular hexagonal silicon pillar 22, a third regular hexagonal silicon pillar 23, a fourth regular hexagonal silicon pillar 24, and three connecting structures 25. The three non-adjacent sides of the first regular hexagonal silicon pillar 21 are respectively connected to one side of the second regular hexagonal silicon pillar 22, the third regular hexagonal silicon pillar 23, and the fourth regular hexagonal silicon pillar 24 through one of the connecting structures 25.

[0021] Specifically, the first regular hexagonal silicon pillar 21, the second regular hexagonal silicon pillar 22, the third regular hexagonal silicon pillar 23, and the fourth regular hexagonal silicon pillar 24 are all the same size; the connecting structure 25 is a cuboid or a cube, the length of the connecting structure is the same as the side length of the regular hexagon on the upper surface of the first regular hexagonal silicon pillar 21, and the height of the connecting structure is the same as the height of the first regular hexagonal silicon pillar 21.

[0022] Along the vertical direction of the upper surface of the substrate 1, a plurality of gyroscope-shaped silicon pillars 2 are arranged at equal intervals; Along the horizontal direction of the upper surface of the substrate 1, with the center of the gyro-shaped silicon pillar 2 as the axis, multiple gyro-shaped silicon pillars 2 are rotated by an angle α in sequence and then arranged at equal intervals, with the centers of the multiple gyro-shaped silicon pillars 2 located on the same horizontal straight line; Wherein, the angle α = n × 60°, and n is an odd number; the adjacent two columns of gyro-shaped silicon pillars 2 are placed in opposite directions, and the multiple columns of gyro-shaped silicon pillars 2 are interlocked.

[0023] Specifically, such as Figure 1 As shown, multiple gyroscope-type silicon pillars 2 are first arranged in a row at equal intervals. All gyroscope-type silicon pillars 2 in the same row face the same direction. For example, in the nth column, all gyroscope-type silicon pillars 2 have one of the following regular hexagonal silicon pillars: the second regular hexagonal silicon pillar 22, the third regular hexagonal silicon pillar 23, and the fourth regular hexagonal silicon pillar 24. The center of the regular hexagonal silicon pillar is located on the central axis of the gyroscope-type silicon pillars 2 in the same column. In this embodiment, this regular hexagonal silicon pillar is defined as a pointing regular hexagonal silicon pillar, and it will be referred to as a pointing regular hexagonal silicon pillar thereafter. The pointing regular hexagonal silicon pillar is located at the first regular hexagonal silicon pillar. Directly above or below the hexagonal silicon pillar 21, all gyroscope-type silicon pillars 2 in the same column are arranged in the same orientation as described above. The entire column of gyroscope-type silicon pillars 2 is either directly above the first hexagonal silicon pillar 21, or directly below the first hexagonal silicon pillar 21. Furthermore, the gyroscope-type silicon pillars 2 in adjacent columns are arranged in opposite directions, that is, the gyroscope-type silicon pillars 2 in adjacent columns point in opposite directions to the first hexagonal silicon pillar 21, and are located directly above and directly below the first hexagonal silicon pillar 21, respectively.

[0024] The gaps between the plurality of gyro-shaped silicon pillars 2 form deep grooves 3; Among them, the deep grooves between the gyroscope-shaped silicon pillars 2 are interconnected to form a gas flow channel, ensuring the gas flow inside the deep groove.

[0025] like Figure 2 As shown, a lower electrode layer 4, a dielectric layer 5, and an upper electrode layer 6 are sequentially deposited on the substrate 1, multiple gyroscope-shaped silicon pillars 2, and deep trench 3; The gyro-shaped deep-groove structure in this embodiment can support the mass production of high aspect ratio silicon capacitors with a depth-to-width ratio > 50:1. Compared with traditional riveted deep-groove silicon capacitors, this structure disperses internal stress through integrated riveted gyro-shaped silicon pillar units, reducing the risk of sidewall cracking and pillar collapse, significantly improving structural stability, and at the same time greatly increasing the overall specific surface area, effectively improving capacitance density.

[0026] Example 2 This embodiment provides a gyro-type deep trench structure silicon capacitor, the structure of which is the same as that shown in Embodiment 1, and will not be repeated here. The only difference is the size of the gyro-type silicon pillar 2, the deep trench 3, and the connection structure 25 of the gyro-type deep trench structure silicon capacitor.

[0027] In the specific implementation process, the dimensions of the gyro-shaped silicon pillar 2, deep trench 3, and connection structure in the gyro-shaped deep trench structure silicon capacitor provided in this embodiment can be adjusted according to the actual working conditions and actual product requirements, so as to take into account both the mechanical stability and specific surface area requirements of the structure.

[0028] The gyro-type deep trench structure silicon capacitor provided in this embodiment also exhibits significant mechanical stability, as shown in the stress distribution diagram. Figure 3 As shown, taking a depth-to-width ratio H of 30:1 as an example, when a shear force of 1 MPa is applied to the side of the gyroscope-shaped silicon pillar 2, the maximum stress generated inside it is 186.49 MPa. Under the same applied shear stress, the stress generated inside the silicon pillar of the gyroscope-shaped deep groove structure is lower than the stress generated inside the silicon pillar of the traditional riveted deep groove structure. Therefore, the gyroscope-shaped deep groove structure can withstand greater mechanical stress, that is, it has better mechanical stability, thereby reducing the situation where the stress accumulates to a large value in actual working conditions, causing cracks or collapse in the silicon pillar, which leads to capacitor failure.

[0029] like Figure 4 , Figure 5 As shown, in a specific embodiment, the silicon substrate 1 is rectangular, and the gyroscope-shaped silicon pillars 2 in the gyroscope-shaped deep trench structure also have five incomplete gyroscope-shaped structures. In this embodiment, the dimensional parameters of the five incomplete gyroscope-shaped structures are shown in the figure: a=0.72μm, b=0.65μm, c=0.36μm, r=1.25μm. The length of the rectangular silicon substrate 1 is [0.72*5+(0.985+1.38775)*4] μm =13.091μm, and the width is (1.25*7+0.65*6) μm =12.65μm. The silicon substrate 1 contains six complete gyroscope-shaped structures, as well as two incomplete structures (structure one, four structures two, two structures three, three structures four, and three structures five). The complete gyroscope structure has a side length of 18a+6b. The effective side length of structure one is 8a+2b, the effective side length of structure two is 10a+4b, the effective side length of structure three is 6a+3b+c, the effective side length of structure four is 14a+4b, and the effective side length of structure five is 10a+4b+2c, totaling 248a+86b+8c=237.34μm.

[0030] The formula for calculating capacitance is: ,in Let be the vacuum permittivity, κ be the relative permittivity of the dielectric material, S be the capacitor surface area, and d be the thickness of the dielectric material. In this deep trench capacitor, the capacitor surface area is ( ) μm, where H is the trench depth. Therefore, the calculated capacitance per unit area is _μm_. .

[0031] Compared to traditional riveted deep-groove silicon capacitors, the gyroscope-type deep-groove silicon capacitor provided in this embodiment has a significantly improved capacitance density.

[0032] The gyro-shaped deep trench silicon capacitor provided in this embodiment uses arrayed gyro-shaped silicon pillars 2 to form interconnected channels inside the deep trench 3. This improves the flow of reactive gas in the deep trench 3, enhances the uniformity of deposition of the lower electrode layer 4, dielectric layer 5 and upper electrode layer 6, and improves the stability and controllability of the process. As a result, a deep trench structure with a higher aspect ratio can be obtained, thereby improving the density and accuracy of the capacitor.

[0033] Example 3 like Figure 6 As shown in the figure, this embodiment provides a method for fabricating a gyroscope-type deep trench silicon capacitor, including the following steps: S1: Photolithography is performed on silicon substrate 1 to form silicon substrate 1 with a photoresist gyroscope pattern array; The photolithography process includes: Positive photoresist is uniformly spin-coated onto silicon substrate 1, and exposure and development operations are performed to obtain silicon substrate 1 covered with a photoresist gyroscope pattern array.

[0034] Specifically, after uniformly spin-coating positive photoresist onto the silicon substrate 1, exposure and development are performed using a photolithography machine to form multiple gyroscope-shaped silicon pillar patterns 2 arranged in an array as in Examples 1 and 2 on the photoresist. Then, the entire substrate surface is treated with oxygen plasma for 10-20 seconds to remove residual photoresist on the silicon surface in areas not covered by photoresist, and to activate the silicon surface in those areas to enhance the adhesion during the next gold deposition, resulting in a silicon substrate 1 covered with a photoresist gyroscope-shaped pattern array, wherein the gyroscope-shaped pattern portion has photoresist, and the other areas are bare silicon substrate 1.

[0035] S2: A gold film is deposited on the silicon substrate 1 covered with a photoresist gyroscope pattern array, and the photoresist gyroscope pattern array is stripped to obtain a silicon substrate 1 with a recessed gyroscope pattern array without photoresist. The thickness of the gold film is less than that of the photoresist, and is 18-25 nanometers. The stripping process refers to removing the photoresist from the gyroscope-shaped pattern portion. The gold film covering the photoresist is stripped off along with the photoresist. At this point, the gyroscope-shaped pattern portion is the exposed silicon substrate 1, while the other areas are covered by the gold film. This silicon substrate 1 is defined as a photoresist-free recessed gyroscope-shaped pattern array silicon substrate 1.

[0036] Specifically, a gold film is deposited on a silicon substrate 1 covered with a photoresist gyroscope pattern array using methods such as thermal evaporation or magnetron sputtering, and then immersed in n-methyl-2-pyrrolidone (NMP) to remove the photoresist and the gold film on the gyroscope pattern portion, while the gold film on the bare silicon remains, thus obtaining a photoresist-free recessed gyroscope pattern array silicon substrate 1.

[0037] S3: The silicon substrate 1 with the recessed gyroscope-shaped pattern array without photoresist is sequentially etched and post-processed to obtain a gyroscope-shaped deep trench structure; The etching process refers to the chemical etching of silicon and gold, namely, the gold-catalyzed chemical etching of the silicon substrate. The post-processing refers to the removal of gold from the bottom of the deep trench 3, cleaning, and drying.

[0038] Specifically, a silicon substrate 1 with a recessed gyroscope-shaped pattern array without photoresist is placed in an etching solution composed of hydrofluoric acid, ethanol, hydrogen peroxide, and deionized water. By controlling the etching time, the composition of the etching solution, and the concentration of each component, different silicon etching depths and etching rates can be obtained. During the etching process, the gold film covering the gyroscope structure acts as a catalyst, and the silicon substrate covered with the gold film is etched. The gold film gradually sinks as the etching progresses and eventually reaches the bottom of the deep trench 3. After the etching process is completed, the etched silicon substrate 1 with the gyroscope-shaped pattern array is placed in a solution composed of iodine and potassium iodide, where the gold is etched away. It is then cleaned with deionized water and anhydrous ethanol, and finally dried in a carbon dioxide critical dryer.

[0039] S4: Sequentially deposit the lower electrode layer 4, the dielectric layer 5, and the upper electrode layer 6 on the gyro-shaped deep trench structure to obtain a silicon capacitor with a gyro-shaped deep trench structure.

[0040] The method for fabricating a gyro-type deep trench silicon capacitor provided in this embodiment can obtain a deep trench structure with a high aspect ratio and vertical silicon wall by controlling the etching solution formulation. Compared with reactive plasma dry etching, it can greatly reduce the manufacturing cost and the aspect ratio is better than that of general dry etching, thus realizing low-cost mass production of gyro-type deep trench silicon capacitors.

[0041] The same or similar labels correspond to the same or similar parts; The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this application. Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A gyroscope-type deep trench silicon capacitor, characterized in that, include: Substrate (1); Multiple gyroscope-shaped silicon pillars (2) arranged in an array perpendicular to the upper surface of the substrate (1), wherein: Along the vertical direction of the upper surface of the substrate (1), a plurality of gyroscope-shaped silicon pillars (2) are arranged at equal intervals; Along the horizontal direction of the upper surface of the substrate (1), with the center of the gyro-shaped silicon pillar (2) as the axis, multiple gyro-shaped silicon pillars (2) are rotated by an angle α and then arranged at equal intervals, with the centers of the multiple gyro-shaped silicon pillars (2) located on the same horizontal straight line; The gaps between the plurality of said gyro-shaped silicon pillars (2) form deep grooves (3); A lower electrode layer (4), a dielectric layer (5), and an upper electrode layer (6) are sequentially deposited on the substrate (1), a plurality of gyro-shaped silicon pillars (2), and a deep trench (3). Each of the gyroscope-type silicon pillars (2) has the same structure, including a first regular hexagonal silicon pillar (21), a second regular hexagonal silicon pillar (22), a third regular hexagonal silicon pillar (23), a fourth regular hexagonal silicon pillar (24) and three connecting structures (25). The three non-adjacent sides of the first regular hexagonal silicon pillar (21) are respectively connected to one side of the second regular hexagonal silicon pillar (22), the third regular hexagonal silicon pillar (23), and the fourth regular hexagonal silicon pillar (24) through one of the connecting structures (25).

2. A gyroscope-type deep trench silicon capacitor according to claim 1, characterized in that, The width of the deep groove (3) is less than the side length of the regular hexagon on the upper surface of the first regular hexagonal silicon pillar (21).

3. A gyroscope-type deep trench silicon capacitor according to claim 2, characterized in that, The first regular hexagonal silicon pillar (21), the second regular hexagonal silicon pillar (22), the third regular hexagonal silicon pillar (23), and the fourth regular hexagonal silicon pillar (24) are all the same size.

4. A gyroscope-type deep trench silicon capacitor according to claim 3, characterized in that, The angle α = n × 60°, where n is an odd number.

5. A gyroscope-type deep trench silicon capacitor according to claim 1, characterized in that, The connecting structure (25) is a cuboid or a cube; The length of the connecting structure is the same as the side length of the regular hexagon on the upper surface of the first regular hexagonal silicon pillar (21); The height of the connecting structure is the same as the height of the first regular hexagonal silicon pillar (21).

6. A method for fabricating a gyroscope-type deep trench silicon capacitor, characterized in that, Includes the following steps: S1: Photolithography is performed on the silicon substrate (1) to form a silicon substrate (1) covered with a photoresist gyroscope pattern array. S2: A gold film is deposited on a silicon substrate (1) covered with a photoresist gyroscope pattern array, and the photoresist gyroscope pattern array is stripped to obtain a silicon substrate (1) with a recessed gyroscope pattern array without photoresist. S3: The silicon substrate (1) with the recessed gyroscope pattern array without photoresist is etched and post-processed in sequence to obtain a gyroscope deep trench structure; S4: Deposit the lower electrode layer (4), the dielectric layer (5) and the upper electrode layer (6) sequentially on the gyro-shaped deep trench structure to obtain a silicon capacitor with a gyro-shaped deep trench structure.

7. The method for fabricating a gyroscope-type deep trench silicon capacitor according to claim 6, characterized in that, In step S1, the photolithography process includes: Positive photoresist was uniformly spin-coated onto a silicon substrate (1), and exposure and development were performed. Then, the surface of the silicon substrate (1) was treated in an oxygen plasma environment to obtain a silicon substrate (1) covered with a photoresist gyroscope pattern array.

8. The method for fabricating a gyroscope-type deep trench silicon capacitor according to claim 6, characterized in that, In step S2, the thickness of the gold film is less than the thickness of the photoresist, and the thickness is 18~25 nanometers.

9. The method for fabricating a gyroscope-type deep trench silicon capacitor according to claim 6, characterized in that, In step S3, the etching process includes: The photoresist-free recessed gyroscope-patterned array silicon substrate (1) is completely immersed in the etching solution. On the upper surface of the photoresist-free recessed gyroscope-patterned array silicon substrate (1), the photoresist in the gyroscope-patterned array area and the gold film on the photoresist are removed, and the remaining areas are covered with a gold film. In the areas covered with the gold film, gold-catalyzed etching of silicon is performed under the action of the etching solution, which includes hydrofluoric acid, ethanol, hydrogen peroxide and deionized water.

10. The method for fabricating a gyroscope-type deep trench silicon capacitor according to claim 6, characterized in that, In step S3, the post-processing includes: removing the gold from the bottom of the gyroscope-shaped deep groove using a mixed solution of iodine and potassium iodide, and cleaning and drying the gyroscope-shaped deep groove structure.

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