Gyroscope structure and preparation method thereof
By introducing a stress relief ring and optimizing the connecting beam structure in a ring resonant MEMS gyroscope, combined with the encapsulation design of the getter layer, the frequency matching and environmental interference problems of existing vibrating ring gyroscopes are solved, achieving a high-stability and low-cost high-performance gyroscope.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHONGQING UNIV
- Filing Date
- 2026-01-28
- Publication Date
- 2026-04-21
AI Technical Summary
Existing vibrating ring gyroscopes suffer from insufficient frequency matching between the driving mode and the detection mode, poor zero-bias stability, limited ability to suppress external environmental interference, and high manufacturing costs, making it difficult to meet the stringent performance requirements of high-end application scenarios.
A gyroscope structure was designed, including a ring resonator, an arc-shaped mass block, a connecting beam, and a stress relief ring. By setting a stress relief ring between the ring resonator and the substrate, adopting an S-shaped and Y-shaped connecting beam structure, and combining it with the encapsulation design of the getter layer, the modal matching degree and anti-interference capability are optimized.
This improves the gyroscope's zero-bias stability, environmental adaptability, and service life, reduces manufacturing costs, enhances its isolation capability from external stress, and improves detection sensitivity and structural reliability.
Smart Images
Figure CN121898358A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microelectromechanical gyroscope technology, specifically to a gyroscope structure and its fabrication method. Background Technology
[0002] A gyroscope is a key inertial sensor used to measure the angular velocity of an object, and it is widely used in navigation, guidance, attitude control, and stabilization systems. Although traditional mechanical gyroscopes have high accuracy, they have inherent drawbacks such as large size, high manufacturing cost, and high power consumption, making it difficult to meet the urgent needs of modern electronic systems for miniaturization, low power consumption, and low cost.
[0003] With the rapid development of Micro-Electro-Mechanical Systems (MEMS) technology, MEMS gyroscopes have emerged. Among them, vibrational gyroscopes have become a research and application hotspot due to their advantages such as compact structure, low power consumption, ease of mass production, and compatibility with integrated circuits. In particular, ring resonant MEMS gyroscopes, with their high symmetry and excellent modal matching potential, show promising prospects in the field of high-performance inertial sensing.
[0004] However, existing vibrating ring gyroscopes still face several technical bottlenecks in practical applications: 1. Insufficient frequency matching between the driving mode and the detection mode leads to poor zero-bias stability; 2. The structure has limited ability to suppress external environmental disturbances (such as temperature drift, air pressure fluctuations and mechanical stress), which affects long-term working accuracy; 3. Some design schemes rely on complex multi-layer processes or high-precision alignment steps, which leads to increased manufacturing costs and limited yield. 4. In high-end application scenarios (such as high-precision navigation, aerospace, etc.), the sensitivity, resolution and long-term reliability of existing devices are still difficult to meet the stringent performance requirements. Summary of the Invention
[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a gyroscope structure and its preparation method, which has a simple structure, low manufacturing process requirements, high symmetry, good modal matching, strong impact resistance and good anti-interference ability.
[0006] In a first aspect, embodiments of this application disclose a gyroscope structure, which includes: Base, Multiple electrodes are evenly distributed circumferentially in a fixed region of the substrate; A ring resonator, as a movable sensing element, is electrically connected to the electrode via leads; Multiple arc-shaped mass blocks are evenly distributed along the inner circumference of the annular resonator, and the arc-shaped contour of the inner side of the arc-shaped mass blocks matches the curvature of the annular resonator. Multiple first connecting beams are evenly distributed around the outer circumference of the annular resonator, with their inner ends connected to the annular resonator and their outer ends connected to stress relief rings. A stress relief ring is arranged around the annular resonator; Multiple second connecting beams connect the stress relief ring to the fixed support area on the base, for isolating external stress.
[0007] In one embodiment, the system further includes a cover and a base, the base being sandwiched between the cover and the base, the upper surface of the base being bonded to the cover, and the lower surface of the base being bonded to the base; The bottom surface of the cover is provided with a first groove, and the first groove is provided with a getter layer. The top surface of the base is provided with a second groove, and / or the bottom surface of the base is provided with a third groove; The annular resonator, multiple arc-shaped mass blocks, multiple first connecting beams, stress relief rings, and multiple second connecting beams are formed on the substrate and located within the clearance space formed by the first groove, the second groove, and / or the third groove, suspended between the cover and the base.
[0008] In one embodiment, the number of the arc-shaped mass blocks is twelve, which are evenly distributed along the inner circumference of the annular resonator; each arc-shaped mass block includes an integrally formed body and a connecting handle, one end of the connecting handle is fixedly connected to the inner wall of the annular resonator, and the other end is connected to the body.
[0009] In one embodiment, the number of the first connecting beams is twenty-four, which are evenly distributed around the outer periphery of the annular resonator. The inner end of each first connecting beam is connected to the annular resonator, and the outer end is connected to the stress relief ring.
[0010] In one embodiment, each of the first connecting beams includes a first connecting segment, an S-shaped segment, and a second connecting segment connected in sequence. The S-shaped segment includes a straight segment and two arc segments respectively connected to both ends of the straight segment. The two arc segments are smoothly connected to the straight segment. The length of each straight segment is 1000~2000μm; the radius of each arc segment is 50~150μm, and the central angle is 200~300°. The first connecting segment is L-shaped and includes a first vertical segment connected to the ring resonator, and a first transverse segment connecting the end of the first vertical segment and one end of the S-shaped segment; The second connecting segment is L-shaped and includes a second vertical segment connected to the stress relief ring, and a second transverse segment connecting the end of the second vertical segment and the other end of the S-shaped segment.
[0011] In one embodiment, the number of the second connecting beams is twenty-four, which are evenly distributed around the outer periphery of the stress relief ring; Each of the second connecting beams includes a main support arm and two symmetrically arranged branch arms. One end of the main support arm is connected to the outside of the stress relief ring, and the other end serves as a connecting node. The two branch arms extend from the connecting node to both sides and are each anchored to a fixed support area on the base.
[0012] In one embodiment, the length y1 of the main arm is 100~200μm, the length y2 of the branch arm is 100~200μm, and the width h at the connection between the main arm and the branch arm is 40~100μm.
[0013] In one embodiment, the electrode includes twenty-four functional electrodes and four ground electrodes, wherein the four ground electrodes are located at the four corners of a rectangular base. The twenty-four functional electrodes are evenly distributed along the circumference of the ring resonator, with a central angle of 15° between two adjacent functional electrodes, and are numbered sequentially from one to twenty-four in a clockwise direction, with electrode one located at 356.5°. The twenty-four functional electrodes are divided into four groups; The first functional electrode group includes electrodes one, two, nine, ten, seventeen, and eighteen, which are used for driving mode excitation; The second functional electrode group includes electrodes three, four, eleven, twelve, nineteen, and twentieth, which are used to detect the displacement response of the mode. The third functional electrode group includes electrodes five, six, thirteen, fourteen, twenty-one, and twenty-two, and their circumferential distribution is the same as that of the first functional electrode group. The fourth functional electrode group includes electrodes seven, eight, fifteen, sixteen, twenty-three, and twenty-four, and their circumferential distribution is the same as that of the second functional electrode group. The third and fourth functional electrode groups are used for redundancy or as backup.
[0014] Secondly, embodiments of this application disclose a method for fabricating a gyroscope structure, comprising: Provide a base; A first patterned photoresist layer is formed on the substrate, and ion implantation is performed on the substrate using the first patterned photoresist layer as a mask to form a conductive region on the surface of the substrate as a lead. A metal layer is sputtered onto the substrate, and the metal layer is patterned by photolithography and etching processes to form multiple electrodes, which are located in a fixed region of the substrate. A second patterned photoresist layer is formed on the substrate. Using the second patterned photoresist layer as a mask, the substrate is etched to integrally form a ring resonator, multiple arc-shaped mass blocks, multiple first connecting beams, a stress relief ring, and multiple second connecting beams on the substrate. The plurality of arc-shaped mass blocks are uniformly distributed along the inner circumference of the annular resonator, and their outer contours match the curvature of the inner wall of the annular resonator. The plurality of first connecting beams are evenly distributed circumferentially along the outer side of the annular resonator, with their inner ends connected to the annular resonator and their outer ends connected to the stress relief ring. The stress relief ring is arranged around the annular resonator; The plurality of second connecting beams connect the stress relief ring to the fixed support area on the base; The ring resonator is electrically connected to the electrode via the lead wire.
[0015] In one embodiment, it further includes: providing a cover and a base, wherein the bottom surface of the cover is provided with a first groove, and the first groove is provided with a getter layer; A third groove is etched on the bottom surface of the substrate, and / or a second groove is etched on the top surface of the base; The base is bonded to the bottom surface of the substrate, and the cover is bonded to the top surface of the substrate, so that the first groove, the second groove and / or the third groove together enclose and form a clearance space; The annular resonator, multiple arc-shaped mass blocks, multiple first connecting beams, stress relief ring, and multiple second connecting beams are located within the clearance space and suspended between the cover and the base.
[0016] The present invention has the following beneficial effects: 1. This invention incorporates a stress relief ring between the ring resonator and the substrate. This stress relief ring primarily isolates external stress interference. Specifically, during manufacturing, the stress relief ring absorbs thermal stress and residual stress generated during encapsulation and etching processes, buffers mechanical impacts during dicing or assembly, and protects the resonator ring from damage or deformation. Under normal operating conditions, the stress relief ring further blocks stress transmission paths caused by external vibrations from the substrate, temperature gradient changes, or deformation of the encapsulation shell, preventing these disturbances from directly affecting the ring resonator and thus preventing resonant frequency drift, vibration mode distortion, or quality factor degradation. Furthermore, the stress relief ring reduces stress accumulation effects during long-term operation, significantly improving the gyroscope's zero-bias stability, environmental adaptability, and service life.
[0017] 2. In this invention, the first connecting beams are evenly distributed around the outer periphery of the annular resonator. Each first connecting beam adopts an S-shaped serpentine configuration and preferably includes a first L-shaped connecting segment, an S-shaped segment, and a second L-shaped connecting segment connected in sequence. While realizing a reliable connection between the annular resonator and the stress relief ring, it significantly reduces the rigid constraint of the supporting structure on the annular resonator and improves the detection sensitivity of weak inertial forces and the structural anti-disturbance capability. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.
[0019] Figure 1 This is a schematic diagram of the gyroscope structure provided in an embodiment of this application.
[0020] Figure 2 This is a schematic diagram showing the connection between the arc-shaped mass block and the ring resonator provided in an embodiment of this application.
[0021] Figure 3 This is a schematic diagram showing the connection between the first connecting beam and the annular resonator provided in an embodiment of this application.
[0022] Figure 4 This is a structural schematic diagram of the first connecting beam provided in an embodiment of this application.
[0023] Figure 5 This is a schematic diagram showing the connection between the second connecting beam, the stress relief ring, and the base, as provided in an embodiment of this application.
[0024] Figure 6 This is a schematic diagram of electrode numbering provided in an embodiment of this application.
[0025] Figure 7 A schematic diagram showing the connection of the cover, base, and substrate provided in an embodiment of this application.
[0026] Figure 8 This is a schematic diagram of the structure of the cover provided in an embodiment of this application.
[0027] Figure 9 This is a schematic diagram of the structure of the base provided in an embodiment of this application.
[0028] Figure 10 This is a schematic diagram of the structure of a silicon wafer provided in an embodiment of this application.
[0029] Figure 11 This is a schematic diagram of the structure after the first patterned photoresist layer is formed on the substrate according to an embodiment of this application.
[0030] Figure 12This is a schematic diagram of the structure after the substrate is formed with leads by ion implantation, according to an embodiment of this application.
[0031] Figure 13 This is a schematic diagram of the structure after a third patterned photoresist layer is formed on the bottom surface of the substrate, according to an embodiment of this application.
[0032] Figure 14 This is a schematic diagram of the structure after the third groove is formed on the bottom surface of the substrate according to an embodiment of this application.
[0033] Figure 15 This is a schematic diagram of the structure after a metal layer is formed on the substrate according to an embodiment of this application.
[0034] Figure 16 This is a schematic diagram of the structure after the second patterned photoresist layer is formed on the substrate according to an embodiment of this application.
[0035] Figure 17 This is a schematic diagram of the structure after the substrate and the cover are bonded together according to an embodiment of this application.
[0036] Figure 18 This is a schematic diagram of the structure after a hard mask layer and a fourth patterned photoresist layer are formed on the bottom surface of the cover in an embodiment of this application.
[0037] Figure 19 This is a schematic diagram of the structure after the first groove is formed on the bottom surface of the cover in an embodiment of this application.
[0038] Figure 20 This is a schematic diagram of the structure after the getter layer is formed in the first groove according to an embodiment of this application.
[0039] Explanation of reference numerals in the attached figures: 1-Base, 2-Electrode, 21-Grounding electrode, 22-Functional electrode, 3-Ring resonator, 4-Arc-shaped mass block, 41-Main body, 42-Connecting handle, 5-First connecting beam, 51-First connecting segment, 511-First vertical segment, 512-First horizontal segment, 52-S-shaped segment, 521-Straight segment, 522-Arc-shaped segment, 53-Second connecting segment, 531-Second vertical segment, 532-Second horizontal segment, 6-Stress relief ring, 7-Second connecting beam, 71-Main support arm, 72-Branch arm, 8-Lead wire, 9-Cover, 91-First groove, 10-Base, 101-Second groove, 11-Getter layer, 12-Third groove; 110 - Silicon nitride layer, 120 - First patterned photoresist layer, 121 - First opening, 130 - Second patterned photoresist layer, 131 - Second opening, 140 - Metal layer, 141 - First chromium layer, 142 - First gold layer, 150 - Third patterned photoresist layer, 151 - Third opening, 160 - Hard mask layer, 161 - Second chromium layer, 162 - Second gold layer, 170 - Fourth patterned photoresist layer. Detailed Implementation
[0040] The embodiments of this application are described below with reference to the accompanying drawings.
[0041] In one embodiment, this application provides a gyroscope structure, see [link to relevant documentation]. Figure 1 As shown, it includes: Base 1, Multiple electrodes 2 are evenly distributed circumferentially in a fixed area of the substrate 1; The ring resonator 3, as a movable sensing element, is electrically connected to the electrode 2 via the lead wire 8; Multiple arc-shaped mass blocks 4 are evenly distributed along the inner circumference of the annular resonator 3, and the arc-shaped contour of the inner side of the arc-shaped mass blocks 3 matches the curvature of the annular resonator 3. Multiple first connecting beams 5 are evenly distributed around the outer circumference of the annular resonator 3, with their inner ends connected to the annular resonator 3 and their outer ends connected to stress relief rings 6. A stress relief ring 6 is arranged around the annular resonator 3; Multiple second connecting beams 7 connect the stress relief ring 6 to the fixed support area on the base 1 to isolate external stress.
[0042] This application incorporates a stress relief ring 6 between the ring resonator 3 and the substrate 1. The stress relief ring 6 primarily serves to isolate external stress interference. Specifically, during manufacturing, the stress relief ring 6 absorbs thermal stress and residual stress generated during encapsulation and etching processes, buffers mechanical impacts during dicing or assembly, and protects the resonator ring from damage or deformation. Under normal operating conditions, the stress relief ring 6 further blocks stress transmission paths caused by external vibrations, temperature gradient changes, or deformation of the encapsulation shell from the substrate 1, preventing these interferences from directly affecting the ring resonator 3, thereby preventing resonant frequency drift, vibration mode distortion, or quality factor degradation. Furthermore, the stress relief ring 6 reduces stress accumulation effects during long-term operation, significantly improving the gyroscope's zero-bias stability, environmental adaptability, and service life.
[0043] As a preferred embodiment of this application, see [link to application]. Figures 7 to 9 As shown, the gyroscope structure provided in this application also includes a cover 9 and a base 10. The base 1 is sandwiched between the cover 9 and the base 10. The upper surface of the base 1 is bonded to the cover 9, and the lower surface of the base 1 is bonded to the base 10, forming a closed three-layer encapsulation structure.
[0044] The bottom surface of the cover 9 is provided with a first groove 91, and the first groove 91 is provided with a getter layer 11; The top surface of the base 10 is provided with a second groove 101, and / or the bottom surface of the base 1 is provided with a third groove 12; The annular resonator 3, multiple arc-shaped mass blocks 4, multiple first connecting beams 5, stress relief ring 6, and multiple second connecting beams 7 are formed on the base 1 and located in the clearance space formed by the first groove 91, the second groove 101, and / or the third groove 12. They are suspended between the cover 9 and the base 10 to avoid physical contact with the encapsulation shell, thereby ensuring that the movable structure has sufficient free movement space during operation and realizing sensitive measurement of high-precision inertial signals.
[0045] The getter layer 11 is activated during the bonding process and can effectively adsorb residual gas molecules within the encapsulation cavity, including water vapor, oxygen, and nitrogen. If these gases are not removed, they will have a significant air damping effect on the MEMS microstructure, reducing the vibration quality factor and thus weakening the gyroscope's sensitivity and response speed. Furthermore, the getter can continuously capture trace amounts of gas released during long-term device operation due to material desorption or interfacial reactions, preventing vacuum levels from decaying over time and fundamentally ensuring the long-term stability of device performance.
[0046] Furthermore, since the getter layer 11 is directly integrated into the first groove 91 of the cover 9, there is no need to occupy additional external space of the package or introduce an independent getter sheet, which simplifies the packaging process and avoids adverse effects on the overall size of the device, making it particularly suitable for miniaturized application scenarios that are sensitive to size.
[0047] Finally, by providing the second groove 101 and the third groove 12 on the base 10 and / or the substrate 1, not only is sufficient vertical clearance space provided for the movable structure, but stress distribution is also further optimized, reducing the transmission of residual stress to the resonator caused by thermal expansion coefficient mismatch during the bonding process, thereby suppressing frequency drift and modal distortion, and improving zero-bias stability and environmental adaptability.
[0048] As a preferred embodiment of this application, see [link to application]. Figure 2 As shown, there are twelve arc-shaped mass blocks 4, which are evenly distributed along the inner circumference of the annular resonator 3; each arc-shaped mass block 4 includes an integrally formed body 41 and a connecting handle 42, one end of the connecting handle 42 is fixedly connected to the inner wall of the annular resonator 3, and the other end is connected to the body 41.
[0049] The core function of the arc-shaped mass block 4 is to adapt to the working mechanism of the ring resonator 3. Its arc-shaped profile, matching the curvature of the ring resonator 3, precisely participates in standing wave vibration, improving vibration stability and energy conversion efficiency. Furthermore, its mass distribution, conforming to the circular motion trajectory, amplifies the mechanical response brought by the Coriolis force, enhancing angular velocity detection sensitivity. Simultaneously, the arc-shaped design of the mass block 4 disperses vibration stress, reduces air damping and structural interference, and its symmetrical distribution maintains the balanced vibration mode of the vibration ring, avoiding interference from non-target modes. This optimizes structural reliability and extends service life while ensuring detection accuracy.
[0050] The one-piece molded body 41 and connecting handle 42 structure avoids the problems of interface loosening or stress concentration caused by traditional split assembly, which not only enhances the overall rigidity of the structure, but also improves manufacturing yield and long-term reliability. As a flexible transition section, the connecting handle 42 effectively buffers local stress while transmitting vibration, preventing fatigue fracture of the body 41 due to high-frequency reciprocating motion.
[0051] As a preferred embodiment of this application, see [link to application]. Figure 1 and Figure 3 As shown, there are twenty-four first connecting beams 5, which are evenly distributed around the outer periphery of the annular resonator 3. The inner end of each first connecting beam 5 is connected to the annular resonator 3, and the outer end is connected to the stress relief ring 6, so as to maintain the annular characteristics as much as possible.
[0052] Further, see Figure 4 As shown, each of the first connecting beams 5 includes a first connecting segment 51, an S-shaped segment 52 and a second connecting segment 53 connected in sequence. The S-shaped segment 52 includes a straight segment 521 and two arc segments 522 respectively connected to both ends of the straight segment 521. The two arc segments 522 are smoothly connected to the straight segment 521. The length L of each straight segment is 1000~2000 μm; the radius R of each arc segment is 50~150 μm, and the central angle α is 200~300°. The first connecting segment 51 is L-shaped and includes a first vertical segment 511 connected to the ring resonator 3, and a first transverse segment 512 connecting the end of the first vertical segment 511 and one end of the S-shaped segment 52. The second connection 53 is L-shaped, including a second vertical segment 531 connected to the stress relief ring 6, and a second transverse segment 532 connecting the end of the second vertical segment 531 and the other end of the S-shaped segment 52.
[0053] Each of the first connecting beams 5 is a "snake" shaped beam. Compared with "U" shaped beams and "L" shaped beams, it is more prone to elastic deformation at the bend, which facilitates the free vibration of the ring resonator, reduces the driving voltage, and improves sensitivity. In other directions (radial and axial), it has high stiffness, is less prone to elastic deformation, and can effectively resist external impacts and vibrations, suppress parasitic modes, and reduce errors. Compared with other beams, the "snake" shaped beam has a longer and more curved structure within the same area, which can more effectively "filter" the vibration energy transmitted from the ring resonator to the base anchor point, helping to obtain a higher mechanical quality factor (Q value), thereby improving the gyroscope's resolution and reducing noise. In terms of quantity, the deformation of the ring in the in-plane third-order mode will produce three vibration peaks and three vibration troughs, and the sine and cosine modes are separated by an angle of 30°. Considering the distribution of signal leads on the ring to cover all vibration extreme points, twelve ion implantation leads are required. The twelve ion implantation leads correspond to twenty-four endpoints, and correspondingly, twenty-four first connecting beams are set.
[0054] As a preferred embodiment of this application, see [link to application]. Figure 1 As shown, there are twenty-four second connecting beams 7, which are evenly distributed around the outer periphery of the stress relief ring 6.
[0055] See Figure 5 As shown, each of the second connecting beams 7 includes a main support arm 71 and two symmetrically arranged branch arms 72. One end of the main support arm 71 is connected to the outside of the stress relief ring 6, and the other end serves as a connection node. The two branch arms 72 extend from the connection node to both sides and are respectively anchored to the fixed support area on the base 1.
[0056] The Y-shaped second connecting beam 7 is radially and evenly distributed between the outer ring base 1 and the inner functional structure, achieving multi-level stress dispersion and flexible connection. See also... Figure 1 As shown, the Y-shaped second connecting beam 7 is also aligned and connected with the serpentine first connecting beam 5 to facilitate signal output, and a lead wire 8 is made on one side to output the signal. Since ion implantation is used as the lead wire 8 in this application, it does not affect the structural symmetry of the second connecting beam 7.
[0057] In traditional straight beam connections, stress transmission is a linear single path. However, the second connecting beam 7 in this application adopts a bifurcated path with main support bearing and branch dispersion: when external stress is transmitted to the second connecting beam 7, the main support arm 71 first bears the initial stress, and then the stress is divided into two paths and transmitted to the inner connection part through two symmetrical branch arms 72, which satisfies the large stress buffer and effectively absorbs external interference such as temperature changes and encapsulates residual stress.
[0058] It should be noted that the outer ring of the gyroscope structure described in this application, namely the stress relief ring 6, is immovable and is only used to isolate stress interference and bear part of the signal output. The inner ring, namely the ring resonator 3, is the resonator sensitive structure and is a movable structure used for sensitive measurement. The design of the outer ring does not affect the internal movable structure. The resonant frequency of the internal movable structure is still consistent with the resonant frequency of the designed outer ring. This preferred embodiment uses a Y-shaped beam instead of a straight beam to better isolate stress. At the same time, the width of the Y-shaped beam is 1.5 to 2 times the width of the internal serpentine beam. The width of the internal first connecting beam 5 is related to the resonant frequency of the structure, but the width of the external second connecting beam 7 is independent of the overall structural parameters. The second connecting beam 7 is wider than the first connecting beam 5, which can better resist stress, is easier to process, and reduces manufacturing difficulty.
[0059] Further, see Figure 5 As shown, the length y1 of the main support arm 71 is 100~200μm, the length y2 of the branch arm 72 is 100~200μm, and the width w at the connection between the main support arm 71 and the branch arm 72 is 40~100μm. This configuration effectively absorbs most of the stress and isolates the stress from interfering with the gyroscope's sensitive structure.
[0060] As a preferred embodiment of this application, see [link to application]. Figure 1 As shown, the number of electrodes 2 consists of twenty-four functional electrodes 22 and four grounding electrodes 21, with the four grounding electrodes 21 located at the four corners of the rectangular base 1. The grounding electrodes 21 serve as a reference plane for electromagnetic shielding, reducing interference from external electromagnetic waves on the electrode signals and preventing the signal radiation from the electrodes 2 themselves from affecting other components; they also provide a unified potential reference (0 potential) for the electrodes 2, avoiding parasitic capacitance and stray currents caused by potential drift between different electrodes 2, thus ensuring the accuracy of signal detection or driving.
[0061] See Figure 6 As shown, the electrode 2 includes twenty-four functional electrodes 22 and four ground electrodes 21, wherein the four ground electrodes 21 are located at the four corners of the rectangular base 1 respectively; The twenty-four functional electrodes 22 are evenly distributed along the circumference of the ring resonator 3, with a central angle of 15° between two adjacent functional electrodes 22, and are numbered from one to twenty-four in a clockwise direction, with electrode one located at 356.5°. The twenty-four functional electrodes are divided into four groups; the first functional electrode group includes electrodes one, two, nine, ten, seventeen, and eighteen, which are used for driving the excitation of the mode; the second functional electrode group includes electrodes three, four, eleven, twelve, nineteen, and twenty, which are used for detecting the displacement response of the mode; the third functional electrode group includes electrodes five, six, thirteen, fourteen, twenty-one, and twenty-two, which are distributed in the same circumferential direction as the first functional electrode group; the fourth functional electrode group includes electrodes seven, eight, fifteen, sixteen, twenty-three, and twenty-four, which are distributed in the same circumferential direction as the second functional electrode group; the third and fourth functional electrode groups are used for redundancy or as spares.
[0062] As a preferred embodiment of this application, see [link to application]. Figure 1 As shown, the leads 8 on the ring resonator 3 are symmetrically distributed, which can better facilitate energy exchange and signal conversion inside the device. It is approximately assumed that the forces generated on the "snake"-shaped first connecting beam 5 cancel each other out. The two ion films on the diagonal form a pair for simultaneous use. The two pairs of leads 8 in the horizontal and vertical directions are used for the excitation generation of the driving mode and the amplitude response output, respectively. The two pairs of leads 8 in the 45° direction can be used for displacement detection of the detection mode and force feedback closed-loop signal input.
[0063] In one embodiment, this application provides a method for fabricating a gyroscope structure, comprising: Provide substrate 1; A first patterned photoresist layer 120 is formed on the substrate 1, and ion implantation is performed on the substrate 1 using the first patterned photoresist layer 120 as a mask to form a conductive region on the surface of the substrate 1 as a lead 8. A metal layer 140 is sputtered on the substrate 1, and the metal layer 140 is patterned by photolithography and etching processes to form a plurality of electrodes 2, the electrodes 2 being located in a fixed region of the substrate 1; A second patterned photoresist layer 130 is formed on the substrate 1. Using the second patterned photoresist layer 130 as a mask, the substrate 1 is etched to integrally form a ring resonator 3, multiple arc-shaped mass blocks 4, multiple first connecting beams 5, stress relief rings 6 and multiple second connecting beams 7 on the substrate 1. The plurality of arc-shaped mass blocks 4 are evenly distributed along the inner circumference of the annular resonator 3, and their outer contours match the curvature of the inner wall of the annular resonator 3. The plurality of first connecting beams 5 are evenly distributed around the outer circumference of the annular resonator 3, with their inner ends connected to the annular resonator 3 and their outer ends connected to the stress relief ring 6. The stress relief ring 6 is arranged around the annular resonator 3; The plurality of second connecting beams 7 connect the stress relief ring 6 to the fixed support area on the base 1; The ring resonator 3 is electrically connected to the electrode 2 via the lead 8.
[0064] In a preferred embodiment of this application, the method for fabricating the gyroscope structure further includes: providing a cover 9 and a base 10, wherein the bottom surface of the cover 9 is provided with a first groove 91, and a getter layer 11 is provided in the first groove 91; etching a third groove 12 to form the bottom surface of the substrate 1, and / or etching a second groove 101 to form the top surface of the base 10; bonding the base 10 to the bottom surface of the substrate 1, and bonding the cover 9 to the top surface of the substrate 1, such that the first groove 91, the second groove 101, and / or the third groove 12 together enclose a clearance space. The annular resonator 3, multiple arc-shaped mass blocks 4, multiple first connecting beams 5, stress relief rings 6, and multiple second connecting beams 7 are located within the clearance space and suspended between the cover 9 and the base 10.
[0065] Specifically, see Figure 10 As shown, a 4-inch double-polished silicon wafer with a thickness of 200μm is provided as substrate 1, and oxidation and nitriding are performed on both sides. A silicon nitride layer 110 is formed on the top and bottom surfaces of substrate 1, and then washed with deionized water and dried for later use.
[0066] See Figure 11 As shown, the silicon nitride layer 110 on the top surface of the substrate 1 is etched using reactive ion etching (RIE), and then the silicon oxide on the top surface of the substrate 1 is removed using buffered oxide etching (BOE) to expose the silicon. Photoresist is then coated onto the exposed silicon surface and exposed and developed to obtain a first patterned photoresist layer 120. A first opening 121 on the first patterned photoresist layer 120, connecting the exposed silicon surface to the outside, is used to define the position of the lead 8.
[0067] See Figure 12 As shown, using the first patterned photoresist layer 120 as a mask, leads 8 are formed on the substrate 1 by ion implantation. High-energy ion implantation technology is used to implant dopant atoms into a specific region of the single-crystal silicon substrate. After annealing, a heavily doped semiconductor region is formed that is lattice-integrated with the silicon substrate and has no physical interface. This region serves as a conductive path, forming an intrinsic and stable ohmic contact with the silicon substrate, and avoids the use of metal electrodes, which can lead to insufficient bonding hermeticity due to the "steps" generated during packaging.
[0068] See Figure 13As shown, the first patterned photoresist layer 120 is removed, and a third patterned photoresist layer 150 is formed on the bottom surface of the substrate 1 by coating, exposure, and development. The third opening 151 on the third patterned photoresist layer 150 is used to define the position of the third groove 12 on the bottom surface of the substrate 1. The silicon nitride layer 110 on the bottom surface of the substrate 1 is removed by RIE, and then the silicon oxide on the bottom surface of the substrate 1 is removed by BOE solution, so that the silicon in the third opening 151 is exposed, and the third patterned photoresist layer 150 is removed.
[0069] See Figure 14 As shown, the bottom surface of substrate 1 is etched using a wet etching process to form a shallow pit, namely the third groove 12, which serves as a movable space to prevent the movable structure from bonding with the glass. The remaining silicon nitride layer 110 and silicon oxide on the bottom surface of substrate 1 are then removed using wet etching, exposing all the silicon. The substrate is then cleaned with deionized water and dried for later use. Prepare 400μm thick borosilicate glass as base 10, clean it with deionized water, and then dry it for later use. See [link to documentation]. Figure 15 As shown, the bottom surface of substrate 1 is anodicly bonded to base 10, and the anchor points in the middle and around the edges are bonded to glass. Under high temperature (300~450℃) and a strong DC electric field, the cations in the borosilicate glass migrate during the silicon-glass anodic bonding, forming an extremely strong electrostatic field at the glass / silicon interface. This promotes atomic-level close contact between the two, and a direct chemical reaction occurs between silicon (Si) and oxygen (O), generating a robust Si-O-Si covalent bond network. This interface is a single-layer atomic-level bond, possessing intrinsic high strength and extremely low gas permeability. The anodicly bonded Si-O-Si covalent bonds have extremely high bond energy and thermal stability; their long-term stability, creep resistance, and temperature resistance are far superior to slurry interfaces that rely on organic binders and glass solidification. Furthermore, the bonding temperature is precisely designed to activate the getter, adsorbing any remaining traces of gas in the cavity, further enhancing and maintaining the vacuum level.
[0070] See Figure 15 As shown, a metal layer 140 is sputtered on the top surface of the substrate 1 to form a Pad electrode for convenient signal extraction. The metal layer 140 includes a first chromium layer 141 and a first gold layer. The first chromium layer 141 is attached to the top surface of the substrate 1, and the first gold layer is attached to the top surface of the first chromium layer 141.
[0071] See Figure 16As shown, a second patterned photoresist layer 130 is formed on the top surface of the substrate 1 by coating, exposure and development. The second opening 131 on the second patterned photoresist layer 130 is used to define the shape and position of the ring resonator 3, multiple arc-shaped mass blocks 4, multiple first connecting beams 5, stress relief ring 6 and multiple second connecting beams 7. Using the second patterned photoresist layer 130 as a mask, an inductively coupled plasma etching (ICP) structure is used to integrally form a ring resonator 3, multiple arc-shaped mass blocks 4, multiple first connecting beams 5, a stress relief ring 6, and multiple second connecting beams 7 on the substrate 1. The multiple arc-shaped mass blocks 4 are uniformly distributed circumferentially along the inner side of the ring resonator 3, and their outer contours match the curvature of the inner wall of the ring resonator 3. The multiple first connecting beams 5 are uniformly distributed circumferentially along the outer side of the ring resonator 3, with their inner ends connected to the ring resonator 3 and their outer ends connected to the stress relief rings 6. The stress relief rings 6 are arranged around the ring resonator 3. The multiple second connecting beams 7 connect the stress relief rings 6 to a fixed support area on the substrate 1. The ring resonator 3 is electrically connected to the electrode 2 via the lead wire 8. The ring resonator 3 and the first connecting beams 5 form a movable structure.
[0072] See Figure 18 As shown, a 4-inch borosilicate glass with a thickness of 400μm is used as the cover 9. A second chromium layer 161 and a second gold layer 162 are sequentially sputtered on the bottom surface of the cover 9 and used as the etching hard mask layer 160.
[0073] See Figure 19 As shown, a pattern is transferred by photolithography on the bottom surface of the cover 9 to form a fourth patterned photoresist layer 170. The exposed second gold layer 162 and second chromium layer 161 defined by the fourth patterned photoresist layer 170 are removed using gold and chromium etching solutions to obtain a three-layer mask. A shallow pit, i.e., a first groove 91, is formed by etching the bottom surface of the cover 9 with hydrofluoric acid HF, creating a movable space, and the three-layer mask is removed. See Figure 20 As shown, a getter is deposited in the first groove 91 to form a getter layer.
[0074] See Figure 17 As shown, the bottom surface of the cover 9 and the top surface of the substrate 1 are aligned and bonded. During the bonding process, the getter is activated, and a small amount of gas remains in the adsorption cavity to maintain a long-term high vacuum environment.
[0075] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.
Claims
1. A gyroscope structure, characterized in that: include: Base (1) Multiple electrodes (2) are uniformly distributed circumferentially in a fixed region of the substrate (1); The ring resonator (3), as a movable sensing element, is electrically connected to the electrode (2) via a lead (8); Multiple arc-shaped mass blocks (4) are evenly distributed along the inner circumference of the ring resonator (3), and the arc-shaped contour of the inner side of the arc-shaped mass blocks (4) matches the curvature of the ring resonator (3); Multiple first connecting beams (5) are evenly distributed around the outer circumference of the annular resonator (3), with their inner ends connected to the annular resonator (3) and their outer ends connected to stress relief rings (6). A stress relief ring (6) is arranged around the annular resonator (3); Multiple second connecting beams (7) connect the stress relief ring (6) to the fixed support area on the base (1) for isolating external stress.
2. The gyroscope structure according to claim 1, characterized in that: It also includes a cover (9) and a base (10), wherein the base (1) is sandwiched between the cover (9) and the base (10), the upper surface of the base (1) is bonded to the cover (9), and the lower surface of the base (1) is bonded to the base (10); The bottom surface of the cover (9) is provided with a first groove (91), and the first groove (91) is provided with a getter layer (11). The top surface of the base (10) is provided with a second groove (101), and / or the bottom surface of the base (1) is provided with a third groove (12). The annular resonator (3), multiple arc-shaped mass blocks (4), multiple first connecting beams (5), stress relief ring (6) and multiple second connecting beams (7) are formed on the base (1) and located in the clearance space formed by the first groove (91), the second groove (101) and / or the third groove (12), suspended between the cover (9) and the base (10).
3. The gyroscope structure according to claim 1, characterized in that: The number of the arc-shaped mass blocks (4) is twelve, and they are evenly distributed along the inner circumference of the annular resonator (3); Each of the arc-shaped mass blocks (4) includes an integrally formed body (41) and a connecting handle (42), one end of which is fixedly connected to the inner wall of the annular resonator (3), and the other end is connected to the body (41).
4. The gyroscope structure according to claim 1, characterized in that: The number of the first connecting beams (5) is twenty-four, which are evenly distributed around the outer periphery of the annular resonator (3). The inner end of each first connecting beam (5) is connected to the annular resonator (3), and the outer end is connected to the stress relief ring (6).
5. The gyroscope structure according to claim 1, characterized in that: Each of the first connecting beams (5) includes a first connecting segment (51), an S-shaped segment (52), and a second connecting segment (53) connected in sequence. The S-shaped segment (52) includes a straight segment (521) and two arc segments (522) respectively connected to both ends of the straight segment (521). The two arc segments (522) are smoothly connected to the straight segment (521). The length L of the straight segment (521) is 1000~2000μm; the radius R of each arc segment (522) is 50~150μm, and the central angle α is 200~300°. The first connecting segment (51) is L-shaped and includes a first vertical segment (511) connected to the ring resonator (3) and a first transverse segment (512) connecting the end of the first vertical segment (511) and one end of the S-shaped segment (52). The second connecting segment (53) is L-shaped and includes a second vertical segment (531) connected to the stress relief ring (6) and a second transverse segment (532) connecting the end of the second vertical segment (531) and the other end of the S-shaped segment (52).
6. The gyroscope structure according to claim 1, characterized in that: The number of the second connecting beams (7) is twenty-four, and they are evenly distributed around the outer periphery of the stress relief ring (6); Each of the second connecting beams (7) includes a main support arm (71) and two symmetrically arranged branch arms (72). One end of the main support arm (71) is connected to the outside of the stress relief ring (6), and the other end serves as a connection node. The two branch arms (72) extend from the connection node to both sides and are anchored to the fixed support area on the base (1).
7. The gyroscope structure according to claim 1, characterized in that: The length y1 of the main support arm (71) is 100~200μm, the length y2 of the branch arm (72) is 100~200μm, and the width h at the connection between the main support arm (71) and the branch arm (72) is 40~100μm.
8. The gyroscope structure according to claim 1, characterized in that: The electrode (2) includes twenty-four functional electrodes (22) and four ground electrodes (21), wherein the four ground electrodes (21) are located at the four corners of the rectangular base (1); The twenty-four functional electrodes (22) are evenly distributed along the circumference of the ring resonator (3), with a central angle of 15° between two adjacent functional electrodes (22), and are numbered from one to twenty-four in a clockwise direction, with electrode one located at 356.5°. The twenty-four functional electrodes are divided into four groups; The first functional electrode group includes electrodes one, two, nine, ten, seventeen, and eighteen, which are used for driving mode excitation; The second functional electrode group includes electrodes three, four, eleven, twelve, nineteen, and twentieth, which are used to detect the displacement response of the mode. The third functional electrode group includes electrodes five, six, thirteen, fourteen, twenty-one, and twenty-two, and their circumferential distribution is the same as that of the first functional electrode group. The fourth functional electrode group includes electrodes seven, eight, fifteen, sixteen, twenty-three, and twenty-four, and their circumferential distribution is the same as that of the second functional electrode group. The third and fourth functional electrode groups are used for redundancy or as backup.
9. A method for fabricating a gyroscope structure, characterized in that, include: Provide a substrate (1); A first patterned photoresist layer (120) is formed on the substrate (1), and ion implantation is performed on the substrate (1) using the first patterned photoresist layer (120) as a mask to form a conductive region as a lead (8) on the surface of the substrate (1). A metal layer (140) is sputtered on the substrate (1), and the metal layer (140) is patterned by photolithography and etching processes to form a plurality of electrodes (2), the electrodes (2) being located in a fixed region of the substrate (1); A second patterned photoresist layer (130) is formed on the substrate (1). The substrate (1) is etched using the second patterned photoresist layer (130) as a mask. A ring resonator (3), multiple arc-shaped mass blocks (4), multiple first connecting beams (5), stress relief rings (6) and multiple second connecting beams (7) are integrally formed on the substrate (1). Among them, the plurality of arc-shaped mass blocks (4) are evenly distributed along the inner circumference of the ring resonator (3), and their outer contours match the curvature of the inner wall of the ring resonator (3); The plurality of first connecting beams (5) are evenly distributed around the outer circumference of the annular resonator (3), with their inner ends connected to the annular resonator (3) and their outer ends connected to the stress relief ring (6). The stress relief ring (6) is arranged around the annular resonator (3); The plurality of second connecting beams (7) connect the stress relief ring (6) to the fixed support area on the base (1); The ring resonator (3) is electrically connected to the electrode (2) via the lead (8).
10. The method for preparing the gyroscope structure according to claim 9, characterized in that, Also includes: Provide a cover (9) and a base (10), wherein the bottom surface of the cover (9) is provided with a first groove (91) and a getter layer (11) is provided in the first groove (91); A third groove (12) is etched on the bottom surface of the substrate (1), and / or a second groove (101) is etched on the top surface of the base (10). The base (10) is bonded to the bottom surface of the base (1), and the cover (9) is bonded to the top surface of the base (1), so that the first groove (91), the second groove (101) and / or the third groove (12) together enclose and form a clearance space; The annular resonator (3), multiple arc-shaped mass blocks (4), multiple first connecting beams (5), stress relief ring (6), and multiple second connecting beams (7) are located within the clearance space and suspended between the cover (9) and the base (10).