MEMS device and manufacturing method therefor

Abstract

The present application provides a MEMS device and a manufacturing method therefor. The device comprises: a first substrate, at least one X-axis and / or Y-axis detection structure being formed on the first substrate; and a second substrate, at least one Z-axis detection structure being formed on the second substrate. The first substrate and the second substrate are bonded to each other, and the at least one X-axis or Y-axis detection structure and the at least one Z-axis detection structure at least partially overlap in a vertical direction to form the MEMS device. In the present application, the overlapping of the detection structures is achieved by bonding the first substrate and the second substrate, thereby reducing orthogonal and zero-bias errors caused by a process, improving the device performance, and reducing the costs of an original cap wafer.

Description

A MEMS device and its manufacturing method Cross-references to related applications

[0001] This patent application claims priority to Chinese Patent Application No. 202510115247.6, filed on January 23, 2025, entitled “A MEMS Device and a Method for Manufacturing the Same Thereof”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of semiconductor technology, and more specifically to a MEMS device and a method for manufacturing the same. Background Technology

[0003] MEMS (Micro-Electro-Mechanical System) refers to a miniature system that integrates mechanical components, drive components, optical systems, and electronic control systems into a single unit. MEMS devices offer advantages such as small size and low power consumption, and have wide applications in various fields including smartphones, tablets, game consoles, automobiles, and drones. Commonly used MEMS chips include accelerometers and gyroscopes. An Inertial Measurement Unit (IMU) is a device that measures an object's three-axis attitude angles (or angular rates) and acceleration.

[0004] In related technologies, detection structures in different directions in MEMS devices are mostly formed in the same layer. However, the detection structures in different directions have structural differences, resulting in different etching rates. This leads to uneven etching of the detection structures in different directions, which seriously affects the zero bias, orthogonality error, post-packaging error and reliability of the device. Summary of the Invention

[0005] The summary of this application introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary is not intended to limit the key and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] To address the existing problems, this application provides a MEMS device comprising: a first substrate on which at least one X-axis and / or Y-axis detection structure is formed; a second substrate on which at least one Z-axis detection structure is formed; the first substrate and the second substrate are bonded to each other, and the at least one X-axis and / or Y-axis detection structure and the at least one Z-axis detection structure at least partially overlap in the vertical direction.

[0007] For example, the device further includes a third substrate located between the first substrate and the second substrate, wherein the first substrate, the third substrate, and the second substrate are bonded to each other; at least one X-axis detection structure and at least one Y-axis detection structure are formed on the first substrate and the third substrate, respectively, or at least one Y-axis detection structure and at least one X-axis structure are formed on the first substrate and the third substrate, respectively; in the MEMS device, at least one X-axis detection structure, at least one Y-axis detection structure, and at least one Z-axis detection structure at least partially overlap in the vertical direction.

[0008] For example, at least one X-axis detection structure and at least one Y-axis detection structure are formed on the first substrate; the at least one X-axis detection structure and at least one Y-axis detection structure overlap at least partially with the at least one Z-axis detection structure in the vertical direction; the MEMS device includes at least one X-axis detection structure, at least one Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

[0009] For example, the MEMS device includes a first device and a second device; at least one X-axis detection structure and at least one Y-axis detection structure of the first device and at least one Z-axis detection structure of the second device are formed on the first substrate; at least one X-axis detection structure and at least one Y-axis detection structure of the second device and at least one Z-axis detection structure of the first device are formed on the second substrate; the at least one X-axis detection structure and at least one Y-axis detection structure of the first device and the at least one Z-axis detection structure of the first device overlap at least partially in the vertical direction, and the at least one X-axis detection structure and at least one Y-axis detection structure of the second device overlap at least partially in the vertical direction; both the first device and the second device include at least one X-axis detection structure, at least one Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

[0010] For example, the MEMS device includes a first device and a second device; at least one X-axis detection structure and at least one Y-axis detection structure of the first device and at least one X-axis detection structure and at least one Y-axis detection structure of the second device are formed on the first substrate; at least one Z-axis detection structure of the first device and at least one Z-axis detection structure of the second device are formed on the second substrate; the at least one X-axis detection structure and at least one Y-axis detection structure of the first device and the at least one Z-axis detection structure of the first device overlap at least partially in the vertical direction, and the at least one X-axis detection structure and at least one Y-axis detection structure of the second device overlap at least partially in the vertical direction; both the first device and the second device include at least one X-axis detection structure, at least one Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

[0011] For example, a cavity is formed between the first substrate and the second substrate, and the first device and the second device are located in the same cavity.

[0012] For example, a first cavity and a second cavity are formed between the second substrate and the first substrate, the first device is located in the first cavity, and the second device is located in the second cavity; the vacuum levels of the first cavity and the second cavity are the same, or the vacuum level of the second cavity is less than that of the first cavity.

[0013] For example, the first device is connected to the second device, and the first cavity and the second cavity are separated by a portion of the segmentation structure, the segmentation structure including detection structures bonded together and formed on different substrates; or, the first device and the second device are spaced apart.

[0014] For example, there is a misalignment between the first substrate and the second substrate; or, the first substrate and the second substrate are aligned in the horizontal direction.

[0015] For example, the first device includes an accelerometer, and the second device includes a gyroscope.

[0016] For example, the at least one X-axis or Y-axis detection structure includes a comb structure, and the Z-axis detection structure includes a flat plate structure; or the at least one X-axis or Y-axis detection structure includes a flat plate structure, and the Z-axis detection structure includes a comb structure.

[0017] For example, a bonding surface is formed between the first substrate and the second substrate, and the thickness of the bonding surface is 0.2 to 5 μm.

[0018] According to another aspect of this application, a method for manufacturing a MEMS device is provided, the method comprising: providing a first substrate and a second substrate, wherein at least one X-axis and / or Y-axis detection structure is formed on the first substrate and at least one Z-axis detection structure is formed on the second substrate; bonding the first substrate and the second substrate to each other such that the at least one X-axis and / or Y-axis detection structure and the at least one Z-axis detection structure at least partially overlap in the vertical direction to obtain at least one MEMS device comprising at least one X-axis and / or Y-axis detection structure and at least one Z-axis detection structure at least partially overlap in the vertical direction.

[0019] For example, the first substrate and the second substrate are bonded to each other by at least one of the following methods: metal bonding, gold-silicon bonding, hybrid bonding, low-temperature bonding, electrostatic bonding, and chemical vapor deposition bonding.

[0020] For example, when the first substrate and the second substrate are bonded at low temperature, the bonding temperature is less than 400 degrees Celsius.

[0021] The MEMS device and its manufacturing method described in this application involve forming an X-axis or Y-axis detection structure on a first substrate and a Z-axis detection structure on a second substrate. The first and second substrates are bonded together so that the X-axis or Y-axis detection structure overlaps with the Z-axis detection structure, thereby forming a MEMS device. This structure, using two substrates for bonding, can reduce orthogonal errors and zero-bias errors introduced by the manufacturing process, thus improving device performance. Furthermore, the movable cavity accommodating the device is formed using this two-substrate structure, which also reduces the cost of traditional capped wafers. Attached Figure Description

[0022] The following drawings, which are incorporated herein by reference and are used to understand this application, illustrate embodiments of the invention and their descriptions to explain the principles of the invention.

[0023] In the attached image:

[0024] Figures 1(a) and 1(b) show schematic diagrams of the structure of an inertial measurement unit in the relevant technology.

[0025] Figure 2 shows a flowchart of the manufacturing method of MEMS devices in an embodiment of this application.

[0026] Figure 3 shows a schematic diagram of the structure of the MEMS device in Embodiment 1 of this application.

[0027] Figure 4 shows a schematic diagram of the MEMS device in Embodiment 2 of this application.

[0028] Figures 5(a)-5(c) show schematic diagrams of the structure of the MEMS device in each step of Embodiment 3 of this application.

[0029] Figures 6(a) and 6(b) show schematic diagrams of MEMS devices with different cavity structures in Embodiment 3 of this application.

[0030] Figures 7(a) and 7(b) show schematic diagrams of the packaging structure of the device in Embodiment 3 of this application.

[0031] Reference numerals: 10, first substrate; 11, first structure; 12, first insulating layer; 13, first bonding region; 20, second substrate; 21, second structure; 22, second insulating layer; 23, second bonding region; 30, third substrate; 31, third structure; 40, first device; 50, second device; 60, metal layer. Detailed Implementation

[0032] The present application will now be described more fully with reference to the accompanying drawings, in which embodiments of the present application are illustrated. However, the present application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0033] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0034] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0036] Embodiments of the application are described herein with reference to cross-sectional views illustrating ideal embodiments (and intermediate structures). Thus, variations from the shapes shown can be anticipated due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of the application should not be limited to the specific shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing processes. For example, implantation regions shown as rectangular typically have rounded or curved features at their edges and / or implantation concentration gradients, rather than a binary change from implantation regions to non-implantation regions. Similarly, buried regions formed by implantation can result in some implantation in the region between the buried region and the surface traversed during implantation. Therefore, the regions shown in the figures are substantially schematic, and their shapes are not intended to show the actual shapes of the regions of the device and are not intended to limit the scope of the application.

[0037] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms as defined in commonly used dictionaries shall be interpreted as having a meaning consistent with their meaning in the relevant field and / or the context of this specification, and not as in an ideal or overly formal sense, unless expressly defined herein.

[0038] To fully understand this application, detailed steps and structures will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0039] Please refer to Figure 1(a), which is a schematic diagram of the structure of an inertial measurement unit in the related technology. It includes a substrate, an insulating layer, a movable structure formed on the insulating layer, and a cap wafer bonded to the substrate structure. The movable structure includes a Z-axis detection structure and an X-axis or Y-axis detection structure. As shown in Figure 1(a), the movable structures in the related technology are disposed on the same layer of the device. Referring to Figure 1(b), the left side of Figure 1(b) shows that the in-plane X and Y-axis detection structures typically employ multiple pairs of comb-like structures with largely similar morphology and etching duty cycles, only their placement is a 90° cross arrangement, resulting in relatively uniform etching consistency. The right side of Figure 1(b) shows that the out-of-plane Z-axis detection structure includes a flat plate structure, and the etched structure is a dense array of release square holes, which differs significantly from the X and Y axis morphology and duty cycle. This leads to etching process errors when the XY and Z axes are etched synchronously due to significant structural differences, ultimately resulting in orthogonal errors in the output signals. These errors are unavoidable due to the inherent properties of the principle and structural design, and cannot be avoided or corrected at the process end.

[0040] To eliminate the impact of orthogonal errors, the conventional approach is to add an orthogonal error compensation module to the back-end integrated circuit and perform calibration through a conditioning program to ultimately correct the orthogonal errors and improve test accuracy. However, this also leads to an increase in the functionality of the integrated circuit module, which in turn increases power consumption, software, and cost, and may also bring risks such as increased heat generation.

[0041] Example 1

[0042] As shown in Figure 2, this application embodiment also provides a MEMS device, comprising: a first substrate 10 and a second substrate 20. At least one X-axis and / or Y-axis detection structure is formed on the first substrate 10, and at least one Z-axis detection structure is formed on the second substrate 20. The first substrate and the second substrate are bonded to each other, and the at least one X-axis and / or Y-axis detection structure and the at least one Z-axis detection structure overlap at least partially in the vertical direction to form the MEMS device.

[0043] Exemplarily, the device includes a first insulating layer 12 disposed on a first substrate 10, a first structure 11 formed on the first insulating layer 12, a second insulating layer 22 disposed on a second substrate 20, and a second structure 21 formed on the second insulating layer 22. The first structure 11 includes X-axis and Y-axis detection structures, and the second structure 21 includes a Z-axis detection structure. A first bonding region 13 and a second bonding region 23 are formed on both sides of the first structure 11 and the second structure 21, respectively. In some embodiments, the first bonding region 13 may be formed on the first insulating layer 12, and the second bonding region 23 may be formed on the second insulating layer 22. Bonding is performed between the first substrate 10 and the second substrate 20 through the first bonding region 13 and the second bonding region 23. After the bonding between the first substrate 10 and the second substrate 20 is achieved, the first structure 11 and the second structure 21 partially overlap in the vertical direction, thereby forming a MEMS device.

[0044] For example, the second substrate 20 serves as both a structural layer and a capping layer for the device. Compared to the device structures in related technologies, this application places the Z-axis detection structure on the second substrate 20, thereby reducing the cost (and space cost) of the original capping wafer.

[0045] In some embodiments, the device is an accelerometer, wherein the X-axis and Y-axis detection structures are comb structures of the accelerometer, and the Z-axis detection structure is a flat plate structure of the accelerometer. Alternatively, the X-axis and Y-axis detection structures are flat plate structures of the accelerometer, and the Z-axis detection structure is a comb structure of the accelerometer. In some embodiments, the device is a gyroscope, wherein the X-axis and Y-axis detection structures are comb structures of the gyroscope, and the Z-axis detection structure is a flat plate structure of the gyroscope. Alternatively, the X-axis and Y-axis detection structures are flat plate structures of the gyroscope, and the Z-axis detection structure is a comb structure of the gyroscope.

[0046] For example, the bonding process between the first and second substrates in this application embodiment can be compatible with various bonding schemes, including traditional anodic bonding and germanium-aluminum bonding. However, traditional bonding has a high bonding temperature, resulting in a long overall process of heating, cooling, and holding, which seriously affects production efficiency. Therefore, this application adopts a low-temperature bonding process, which has the advantages of high production efficiency per unit time, low bonding temperature, and high alignment accuracy. Furthermore, the number of bonding layers can be continuously increased to improve chip performance and manufacture high-precision, high-performance inertial sensors. Specifically, the bonding temperature is less than 400 degrees Celsius, and the bonding surface thickness is 0.2–5 μm. Examples of bonding surface thicknesses include 0.2 μm, 0.5 μm, 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm, 3.0 μm, 3.5 μm, 4.0 μm, 4.5 μm, and 5.0 μm. In some embodiments, the bonding region includes a metal layer, and the bonding method can also be mixed bonding, metal-to-metal bonding, gold-silicon bonding between metal and Si, as well as electrostatic bonding, chemical vapor deposition bonding, etc. The specific bonding method can be determined according to the actual situation.

[0047] The MEMS device in this embodiment forms an X-axis or Y-axis detection structure on a first substrate 10 and a Z-axis detection structure on a second substrate 20. The X-axis or Y-axis detection structure overlaps with the Z-axis detection structure through bonding the first substrate 10 and the second substrate 20. Bonding the two substrates reduces orthogonal errors and zero-bias errors introduced by the manufacturing process, improving device performance. Furthermore, the movable cavity accommodating the device is formed using the two-substrate structure, which also reduces the cost of the original capped wafer.

[0048] For example, the first substrate and the second substrate in the embodiments of this application may be a wafer or a part of a wafer, wherein the second substrate may be a cap wafer or a part of a cap wafer.

[0049] As shown in Figure 3, in order to solve the above problems, this application embodiment also provides a method for manufacturing a MEMS device, the method including the following steps:

[0050] S310. A first substrate and a second substrate are provided, wherein at least one X-axis and / or Y-axis detection structure is formed on the first substrate, and at least one Z-axis detection structure is formed on the second substrate.

[0051] S320. Bond the first substrate and the second substrate to each other so that at least one X-axis and / or Y-axis detection structure and at least one Z-axis detection structure overlap at least partially in the vertical direction to obtain at least one MEMS device, which includes at least one X-axis and / or Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

[0052] The MEMS device manufacturing method in this application involves forming an X-axis or Y-axis detection structure on a first substrate and a Z-axis detection structure on a second substrate. The X-axis or Y-axis detection structure overlaps with the Z-axis detection structure through bonding the first and second substrates, thereby forming a MEMS device. Bonding two substrates reduces orthogonal errors and zero-bias errors introduced by the manufacturing process, improving device performance. Furthermore, the movable cavity accommodating the device is formed using a two-substrate structure, reducing the cost of the original cap substrate.

[0053] For example, the method further includes: after providing a first substrate and a second substrate, forming a first insulating layer on the surface of the first substrate and forming a second insulating layer on the surface of the second substrate; the structure of the X-axis or Y-axis is formed on the first insulating layer, and the structure of the Z-axis is formed on the second insulating layer.

[0054] For example, in the above method, in step S310, at least one X-axis detection structure and at least one Y-axis detection structure are formed on the first substrate.

[0055] In step S320, the first substrate and the second substrate are bonded to each other, so that at least one X-axis detection structure and at least one Y-axis detection structure overlap at least partially with at least one Z-axis detection structure in the vertical direction.

[0056] In some embodiments, the method further includes cutting the first substrate and the second substrate to cut the bonded first substrate and the second substrate to obtain at least one MEMS device, which includes at least one X-axis detection structure and at least one Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

[0057] The MEMS device obtained by the above method has X-axis and Y-axis detection structures formed simultaneously on the first substrate. When combined with the Z-axis detection structure on the second substrate, it forms a movable structure of a triaxial inertial sensor.

[0058] Example 2

[0059] This application provides a MEMS device, which differs from the one in Embodiment 1 above in that:

[0060] The MEMS device also includes a third substrate. When at least one X-axis detection structure is formed on the first substrate, at least one Y-axis detection structure is formed on the third substrate; when at least one Y-axis detection structure is formed on the first substrate, at least one X-axis detection structure is formed on the third substrate.

[0061] The first substrate, the third substrate, and the second substrate are bonded to each other, such that at least one X-axis detection structure, at least one Y-axis detection structure, and at least one Z-axis detection structure at least partially overlap in the vertical direction. The third substrate is located between the first substrate and the second substrate, and its two sides are bonded to the first substrate and the second substrate, respectively.

[0062] MEMS devices include at least one X-axis detection structure, at least one Y-axis detection structure, and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

[0063] In the process of forming the MEMS device in the embodiments of this application, the step of etching away the substrate on the third substrate so that the detection structures on the XYZ axis overlap each other is also included.

[0064] For example, a MEMS device includes an X-axis detection structure, a Y-axis detection structure, and a Z-axis detection structure, thereby forming a multi-axis detection device. In some embodiments, there are multiple (e.g., two) detection structures for each of the X, Y, and Z axes, thereby improving the detection sensitivity of the MEMS device.

[0065] Figure 4 shows a MEMS device according to an embodiment of this application, including a first substrate 10, a third substrate 30 bonded to the first substrate 10, and a second substrate 20 bonded to the third substrate 30. A first structure 11 and a third structure 31 are formed on the first substrate 10 and the third substrate 30, respectively, where the first structure 11 and the third structure 31 are the X-axis and Y-axis detection structures of the device (or the first structure 11 and the third structure 31 are the Y-axis and X-axis detection structures of the device, respectively). A second structure 21 is formed on the second substrate 20, where the second structure 21 is the Z-axis detection structure of the device. The X-axis and Y-axis detection structures include a comb-like structure, and the Z-axis detection structure includes a flat plate structure, or the X-axis and Y-axis detection structures include a flat plate structure, and the Z-axis detection structure includes a comb-like structure.

[0066] A first insulating layer 12 is formed on the first substrate 10, and an X-axis detection structure (or a Y-axis detection structure) is formed on the first insulating layer 12. A second insulating layer 22 is formed on the second substrate 20, and a Z-axis detection structure is formed on the second insulating layer 22. The X-axis detection structure, the Y-axis detection structure, and the Z-axis detection structure overlap to form a movable structure of the device.

[0067] For example, the device in the embodiments of this application includes an accelerometer or a gyroscope, and the detection structures of the X, Y, and Z axes correspond to the movable structures within the accelerometer or gyroscope.

[0068] The MEMS device in this embodiment adopts a three-layer bonding process, which can effectively reduce the mutual influence between the design structures. The structures in the three axes are etched separately and then mixed and bonded to form a three-layer vertical structure, which can further reduce the orthogonality error.

[0069] Example 3

[0070] This application provides a MEMS device, which differs from Embodiment 1 described above in that:

[0071] At least one X-axis detection structure and at least one Y-axis detection structure of a first device and at least one Z-axis detection structure of a second device are formed on a first substrate.

[0072] At least one X-axis detection structure and at least one Y-axis detection structure of the second device and at least one Z-axis detection structure of the first device are formed on the second substrate.

[0073] The first substrate and the second substrate are bonded to each other such that at least one X-axis detection structure and at least one Y-axis detection structure of the first device at least partially overlap with at least one Z-axis detection structure of the first device in the vertical direction, and at least one X-axis detection structure and at least one Y-axis detection structure of the second device at least partially overlap with at least one Z-axis detection structure of the second device in the vertical direction.

[0074] Both the first device and the second device include at least one X-axis detection structure, at least one Y-axis detection structure, and at least one Z-axis detection structure that at least partially overlap in the vertical direction.

[0075] Compared to Embodiment 1, the MEMS device in this embodiment has a structure of at least two devices on the first substrate, namely, partially movable structures of the first and second devices. The second substrate also has partially movable structures of two devices. The first and second devices can be simultaneously obtained by bonding the first and second substrates. Specifically, the X and Y axis detection structures of the first device and the Z axis detection structure of the second device are respectively disposed on the first substrate, while the Z axis detection structure of the first device and the X and Y axis detection structures of the second device are respectively disposed on the second substrate. Through bonding the first and second substrates, the X, Y, and Z axis detection structures of the first device overlap to form the first device. The X, Y, and Z axis detection structures of the second device overlap to form the second device.

[0076] In this configuration, the first device is an accelerometer and the second device is a gyroscope, or the first device is a gyroscope and the second device is an accelerometer.

[0077] In some embodiments, a movable structure of the same type as the first device and the second device is formed on a first substrate, and a movable structure of the same type as the first device and the second device is formed on a second substrate. Specifically:

[0078] At least one X-axis detection structure and at least one Y-axis detection structure of a first device and at least one X-axis detection structure and at least one Y-axis detection structure of a second device are formed on a first substrate.

[0079] At least one Z-axis detection structure of the first device and at least one Z-axis detection structure of the second device are formed on the second substrate.

[0080] The first substrate and the second substrate are bonded to each other such that at least one X-axis detection structure and at least one Y-axis detection structure of the first device at least partially overlap with at least one Z-axis detection structure of the first device in the vertical direction, and at least one X-axis detection structure and at least one Y-axis detection structure of the second device at least partially overlap with at least one Z-axis detection structure of the second device in the vertical direction.

[0081] Both the first device and the second device include at least one X-axis detection structure, at least one Y-axis detection structure, and at least one Z-axis detection structure that at least partially overlap in the vertical direction.

[0082] For example, X and Y axis detection structures of a first device and X and Y axis detection structures of a second device are respectively disposed on a first substrate. Simultaneously, Z axis detection structures of the first device and the second device are respectively disposed on a second substrate. A cavity is formed by bonding the first and second substrates. The X, Y, and Z axis detection structures of the first device overlap to form the first device within the cavity. The X, Y, and Z axis detection structures of the second device overlap to form the second device within the cavity.

[0083] The following description uses the same type of movable structure formed on the first substrate and the second substrate, respectively, as examples, in conjunction with Figure 5. Figures 5(a)-5(c) show cross-sectional schematic diagrams of the MEMS device in each step of the embodiments of this application. Referring to Figure 5(a), firstly, a first insulating layer 12 is formed on the first substrate 10, and a first structure 11 and a first bonding region 13 are formed on the first insulating layer 12. Simultaneously, a first cavity is formed by etching, wherein the first structure 11 is the movable structure of the first device 40 and the second device 50. Referring to Figure 5(b), a second insulating layer 22 is formed on the second substrate 20, and a second structure 21 and a second bonding region 23 are formed on the second insulating layer 22. Simultaneously, a second cavity is formed by etching, wherein the second structure 21 includes another part of the movable structure of the first device 40 and the second device 50. As shown in Figure 5(c), the first bonding region 13 on the first substrate 10 and the second bonding region 23 on the second substrate 20 are bonded together, and the first cavity and the second cavity form a closed cavity, resulting in the first device 40 and the second device 50, which together form a MEMS device structure.

[0084] For example, in Figure 5, the first device 40 is an accelerometer, and the second device 50 is a gyroscope. The first structure 11 on the first substrate 10 includes an XY-axis detection structure (accelerometer comb structure) for the accelerometer and an XY-axis detection structure (gyroscope comb structure) for the gyroscope. The second structure 21 on the second substrate 20 includes a Z-axis detection structure (accelerometer flat plate structure) for the accelerometer and a Z-axis detection structure (gyroscope flat plate structure) for the gyroscope. The first device 40 and the second device 50 are housed in a closed cavity formed by the first cavity and the second cavity. This constitutes a monolithically integrated six-axis inertial sensor. In some embodiments, the first device 40 and the second device 50 can be a gyroscope and an accelerometer, respectively.

[0085] Please refer to Figures 5(c)-6(b), which show three different MEMS devices in this embodiment. The main difference between the three is that the first device 40 and the second device 50 have different cavities. First, as shown in Figure 5(c), the first device 40 and the second device 50 use a common closed cavity. As shown in Figure 6(a), the first device 40 and the second device 50 use different cavities. The two cavities are separated by a portion of the first structure 11, the second structure 21, the first bonding region 13, and the second bonding region 23 to form a first cavity and a second cavity. The first device 40 and the second device 50 are located in different first cavities and second cavities, respectively, and the two closed cavities are not interconnected. The vacuum levels of the two closed cavities can be the same or different. For example, both vacuum levels are less than 10. -8Pa. For example, the first cavity and the second cavity can also be low-pressure chambers. In some cases, the first device 40 and the second device 50 may require different pressures and vacuum levels. Using a device structure with different enclosed cavities as shown in Figure 6(a) better meets practical needs. Specifically, when the vacuum levels of the first cavity and the second cavity are different, the vacuum level of the second cavity is less than that of the first cavity.

[0086] As shown in Figure 6(b), compared with Figure 6(a), the first device 40 and the second device 50 in this application are also located in different enclosed cavities, but the first device 40 and the second device 50 are not connected. They can be separated by a distance and located at different positions on the integrated circuit. This arrangement is more flexible and facilitates the wiring and configuration of the integrated circuit. As mentioned above, after bonding the first substrate 10 and the second substrate 20, the method in this application also includes a step of cutting the first substrate 10 and the second substrate 20. During the cutting process, the first device 40 and the second device 50 can be separated so that they are independent of each other to form the device structure in Figure 6(b).

[0087] Figure 7(a) shows a schematic diagram of the MEMS device packaging in an embodiment of this application. The device includes a first substrate 10 and a second substrate 20. A first insulating layer 12 is formed on the first substrate 10, and a second insulating layer 22 is formed on the second substrate 20. A first structure 11 is formed on the first insulating layer 12, and a second structure 21 is formed on the second insulating layer 22. A first bonding region 13 is formed on the first structure 11, and a second bonding region 23 is formed on the second structure 21. Bonding is performed through the first bonding region 13 and the second bonding region 23, thereby forming a cavity structure. There is a misalignment between the two sides of the first substrate 10 and the second substrate 20 after bonding. The first structure 11 includes an XY axis detection structure, and the second structure 21 includes a Z axis detection structure. After bonding, the XY axis detection structure and the Z axis detection structure overlap in the vertical direction. In addition, a metal layer 60 is formed on both the first structure 11 and the second structure 21, and the structure of the metal layer 60 enables the connection between the MEMS device and the external circuit. This connection method allows for routing from inside the device, facilitating circuit design and packaging.

[0088] Figure 7(b) shows a schematic diagram of another packaging method for MEMS devices. It uses TSV (Three-Dimensional Integrated Packaging) technology for packaging. The device includes a first substrate 10 and a second substrate 20. A first insulating layer 12 is formed on the first substrate 10, and a second insulating layer 22 is formed on the second substrate 20. A first structure 11 is formed on the first insulating layer 12, and a second structure 21 is formed on the second insulating layer 22. A first bonding region 13 is formed on the first structure 11, and a second bonding region 23 is formed on the second structure 21. The first bonding region 13 and the second bonding region 23 are bonded together to form a cavity structure. After bonding, the two sides of the first substrate 10 and the second substrate 20 are aligned in the horizontal direction. The first structure 11 includes an XY-axis detection structure, and the second structure 21 includes a Z-axis detection structure. After bonding, the XY-axis detection structure and the Z-axis detection structure overlap in the vertical direction. The difference from the structure in Figure 7(a) is that a metal layer 60 is formed on the outer surface of the first substrate 10 and the second substrate 20. The metal layer 60 is electrically connected to the MEMS device for connection with external circuits. Compared with the device structure in Figure 7(a), the advantage of this structure is that the first substrate 10 and the second substrate 20 are aligned, and the overall space occupied is smaller, saving more area.

[0089] In summary, the MEMS device and its manufacturing method in this application form an X-axis and Y-axis detection structure on a first substrate and a Z-axis detection structure on a second substrate. The X-axis and Y-axis detection structures overlap with the Z-axis detection structure through bonding the first and second substrates, thereby forming the MEMS device. Bonding the two substrates reduces orthogonal and zero-bias errors introduced by the manufacturing process, improving device performance. Furthermore, the movable cavity accommodating the device is formed using the two-substrate structure, reducing the cost of the original cap wafer. Separating the XY-axis comb structure and the Z-axis flat structure of the inertial sensor significantly reduces orthogonal errors caused by etching errors due to pattern differences, making it easier to fabricate high-precision inertial sensors.

[0090] Although several embodiments have been described herein, it should be understood that many other modifications and embodiments will be conceived by those skilled in the art, all of which will fall within the scope of the concept disclosed herein. More specifically, various modifications and changes may be made in terms of the arrangement and / or components of the subject matter within the scope of this disclosure, the drawings, and the appended claims. In addition to modifications and changes in components and / or arrangement, the use of alternative methods will also be obvious to those skilled in the art.

Claims

1. A MEMS device, characterized in that, The device includes: A first substrate (10) having at least one X-axis and / or Y-axis detection structure formed thereon; A second substrate (20) having at least one Z-axis detection structure formed thereon; The first substrate (10) and the second substrate (20) are bonded to each other, and the at least one X-axis and / or Y-axis detection structure overlaps at least partially with the at least one Z-axis detection structure in the vertical direction to form the MEMS device.

2. The MEMS device according to claim 1, characterized in that, The device further includes a third substrate (30) located between the first substrate (10) and the second substrate (20), wherein the first substrate (10), the third substrate (30) and the second substrate (20) are bonded to each other; At least one X-axis detection structure and at least one Y-axis detection structure are formed on the first substrate (10) and the third substrate (30), respectively; or, at least one Y-axis detection structure and at least one X-axis structure are formed on the first substrate (10) and the third substrate (30), respectively. In the MEMS device, at least one X-axis detection structure, at least one Y-axis detection structure, and at least one Z-axis detection structure overlap at least partially in the vertical direction.

3. The MEMS device according to claim 1, characterized in that, At least one X-axis detection structure and at least one Y-axis detection structure are formed on the first substrate (10); the at least one X-axis detection structure and at least one Y-axis detection structure overlap at least partially with the at least one Z-axis detection structure in the vertical direction; The MEMS device includes at least one X-axis detection structure, at least one Y-axis detection structure, and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

4. The MEMS device according to claim 3, characterized in that, The MEMS device includes a first device (40) and a second device (50); At least one X-axis detection structure and at least one Y-axis detection structure of the first device (40) and at least one Z-axis detection structure of the second device (50) are formed on the first substrate (10); At least one X-axis detection structure and at least one Y-axis detection structure of the second device (50) and at least one Z-axis detection structure of the first device (40) are formed on the second substrate (20); The at least one X-axis detection structure and at least one Y-axis detection structure of the first device (40) overlap at least partially with the at least one Z-axis detection structure of the first device (40) in the vertical direction, and the at least one X-axis detection structure and at least one Y-axis detection structure of the second device (50) overlap at least partially with the at least one Z-axis detection structure of the second device (50) in the vertical direction. Both the first device (40) and the second device (50) include at least one X-axis detection structure and at least one Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

5. The MEMS device according to claim 3, characterized in that, The MEMS device includes a first device (40) and a second device (50); At least one X-axis detection structure and at least one Y-axis detection structure of the first device (40) and at least one X-axis detection structure and at least one Y-axis detection structure of the second device (50) are formed on the first substrate (10); At least one Z-axis detection structure of the first device (40) and at least one Z-axis detection structure of the second device (50) are formed on the second substrate (20); The at least one X-axis detection structure and at least one Y-axis detection structure of the first device (40) overlap at least partially with the at least one Z-axis detection structure of the first device (40) in the vertical direction, and the at least one X-axis detection structure and at least one Y-axis detection structure of the second device (50) overlap at least partially with the at least one Z-axis detection structure of the second device in the vertical direction. Both the first device (40) and the second device (50) include at least one X-axis detection structure and at least one Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

6. The MEMS device according to claim 4 or 5, characterized in that, A cavity is formed between the first substrate (10) and the second substrate (20), and the first device (40) and the second device (50) are located in the same cavity.

7. The MEMS device according to claim 4 or 5, characterized in that, A first cavity and a second cavity are formed between the second substrate (20) and the first substrate (10), the first device (40) is located in the first cavity, and the second device (50) is located in the second cavity; The first cavity and the second cavity have the same vacuum level, or the second cavity has a lower vacuum level than the first cavity.

8. The MEMS device according to claim 7, characterized in that, The first device (40) is connected to the second device (50), and the first cavity and the second cavity are separated by a partition structure, the partition structure including detection structures bonded together and formed on different substrates; or, The first device (40) and the second device (50) are spaced apart.

9. The MEMS device according to claim 7, characterized in that, There is a misalignment between the first substrate (10) and the second substrate (20); or, the first substrate (10) and the second substrate (20) are aligned in the horizontal direction.

10. The MEMS device according to any one of claims 4 to 9, characterized in that, The first device (40) includes an accelerometer, and the second device (50) includes a gyroscope.

11. The MEMS device according to any one of claims 1-10, characterized in that, The at least one X-axis or Y-axis detection structure includes a comb-tooth structure, and the Z-axis detection structure includes a flat plate structure; or the at least one X-axis or Y-axis detection structure includes a flat plate structure, and the Z-axis detection structure includes a comb-tooth structure.

12. The MEMS device according to any one of claims 1-11, characterized in that, A bonding surface is formed between the first substrate (10) and the second substrate (20), and the thickness of the bonding surface is 0.2 to 5 μm.

13. A method for manufacturing a MEMS device, characterized in that, The method includes: A first substrate (10) and a second substrate (20) are provided, wherein at least one X-axis and / or Y-axis detection structure is formed on the first substrate (10) and at least one Z-axis detection structure is formed on the second substrate (20); The first substrate (10) and the second substrate (20) are bonded to each other, such that the at least one X-axis and / or Y-axis detection structure and the at least one Z-axis detection structure overlap at least partially in the vertical direction to obtain at least one MEMS device comprising at least one X-axis and / or Y-axis detection structure and at least one Z-axis detection structure that overlap at least partially in the vertical direction.

14. The method according to claim 13, characterized in that, The first substrate (10) and the second substrate (20) are bonded to each other by at least one of the following methods: metal bonding, gold-silicon bonding, hybrid bonding, low-temperature bonding, electrostatic bonding, and chemical vapor deposition bonding.

15. The method according to claim 13, characterized in that, When the first substrate (10) and the second substrate (20) are bonded at low temperature, the bonding temperature is less than 400 degrees Celsius.

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