MEMS device and manufacturing method therefor, and electronic device

Abstract

A MEMS device and a manufacturing method therefor, and an electronic device. The manufacturing method comprises: providing a first substrate (210) and a second substrate (220), wherein a first sacrificial layer (213) is formed on the surface of the first substrate (210), and a second sacrificial layer (223) is formed on the surface of the second substrate (220); forming a first structural layer (214) on the first sacrificial layer (213), and forming a second structural layer (224) on the second sacrificial layer (223), wherein the first structural layer (214) comprises a first structural region and a first bonding region, and the second structural layer (224) comprises a second structural region and a second bonding region; forming a first MEMS structure (215) in the first structural region, and forming a second MEMS structure (225) in the second structural region; forming a first cavity (216) and a second cavity (226); and bonding the first structural layer (214) and the second structural layer (224), such that the first cavity (216) and the second cavity (226) together form a cavity. The non-planar layout reduces the area of the MEMS device, reducing costs and device noise, while also improving the impact resistance of the device.

Description

A MEMS device, a manufacturing method thereof and an electronic device TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, in particular to a MEMS device, a manufacturing method thereof and an electronic device. BACKGROUND

[0002] MEMS (Micro-Electro-Mechanical System) refers to a micro system integrating mechanical components, driving components, optical systems and electrical control systems into one whole. MEMS devices have the advantages of small size and low power consumption, and have a wide range of application scenarios in smart phones, tablet computers, game consoles, automobiles, unmanned aerial vehicles and other fields. Commonly used MEMS chips include accelerometers, gyroscopes and the like.

[0003] An IMU (Inertial Measurement Unit) is a device for measuring the three-axis attitude angle (or angular rate) and acceleration of an object. Generally, an IMU includes three single-axis accelerometers and three single-axis gyroscopes to realize six-axis sensing functions. In order to reduce the chip size and cost, the six-axis sensing functions are integrated and manufactured on one chip by using the same processing flow.

[0004] However, the IMU structure in the related art generally adopts a planar layout mode, resulting in a large device area, poor mechanical impact resistance, large device noise, and thus reduced device performance and yield. SUMMARY

[0005] A series of simplified concepts are introduced in the summary section, which will be further described in detail in the specific embodiments section. The summary section of the present application does not mean to attempt to limit the key features and necessary technical features of the claimed technical solutions, nor to attempt to determine the protection scope of the claimed technical solutions.

[0006] In view of the existing problems, the present application provides a manufacturing method of a MEMS device, comprising:

[0007] providing a first substrate and a second substrate, a first sacrificial layer is formed on the surface of the first substrate, and a second sacrificial layer is formed on the surface of the second substrate;

[0008] forming a first structure layer on the first sacrificial layer, and forming a second structure layer on the second sacrificial layer, the first structure layer includes a first structure region and a first bonding region located outside the first structure region, and the second structure layer includes a second structure region corresponding to the first structure region and a second bonding region corresponding to the first bonding region;

[0009] forming a first MEMS structure in the first structure region and a second MEMS structure in the second structure region;

[0010] etching part of the first sacrificial layer to form a first cavity and etching part of the second sacrificial layer to form a second cavity;

[0011] bonding the first structure layer and the second structure layer through the first bonding region and the second bonding region, the first cavity and the second cavity together forming a cavity accommodating the first MEMS structure and the second MEMS structure.

[0012] Exemplarily, the first structure layer and the second structure layer are bonded through the first bonding region and the second bonding region by a hybrid bonding process.

[0013] Exemplarily, before forming the first MEMS structure and the second MEMS structure, the method further comprises:

[0014] etching the first structure layer of the first structure region by a first thickness to lower the surface of the first structure region below the surface of the first bonding region, and etching the second structure layer of the second structure region by a second thickness to lower the surface of the second structure region below the surface of the second bonding region.

[0015] Exemplarily, the first thickness and the second thickness are in the range of 4 μm-6 μm.

[0016] Exemplarily, the cavity is a vacuum cavity, and the vacuum degree of the cavity is less than 10 -8 Pa.

[0017] Exemplarily, the first MEMS structure comprises a comb structure of a gyroscope, and the second MEMS structure comprises a comb structure of an accelerometer.

[0018] Another aspect of the present application provides a MEMS device, comprising:

[0019] a first substrate;

[0020] a first sacrificial layer on the first substrate, a first cavity being formed in the first sacrificial layer;

[0021] a first structure layer on the first sacrificial layer, comprising a first structure region and a first bonding region outside the first structure region, and a first MEMS structure being formed in the first structure region;

[0022] a second structure layer on the first structure layer, comprising a second structure region corresponding to the first structure region and a second bonding region corresponding to the first bonding region, and a second MEMS structure is formed in the second structure region;

[0023] a second sacrificial layer on the second structure layer, and a second cavity is formed in the second sacrificial layer;

[0024] a second substrate on the second sacrificial layer;

[0025] wherein the first cavity and the second cavity jointly form a cavity accommodating the first MEMS structure and the second MEMS structure.

[0026] Exemplarily, a surface of the first structure region towards the second MEMS structure is lower than a surface of the first bonding region towards the second MEMS structure by 4-6 μm;

[0027] a surface of the second structure region towards the first MEMS structure is higher than a surface of the second bonding region towards the first MEMS structure by 4-6 μm.

[0028] Exemplarily, the cavity is a vacuum cavity, and a vacuum degree of the cavity is less than 10 -8 Pa.

[0029] Exemplarily, a first insulating layer is further formed on a surface of the first substrate, a first interconnection layer is further formed on the first insulating layer, and the first sacrificial layer is on the first interconnection layer and the first insulating layer; a second insulating layer is further formed on a surface of the second substrate, a second interconnection layer is further formed on the second insulating layer, and the second sacrificial layer is on the second interconnection layer and the second insulating layer;

[0030] the first structure layer partially extends into the first sacrificial layer and is in contact with the first interconnection layer, and the second structure layer partially extends into the second sacrificial layer and is in contact with the second interconnection layer.

[0031] In still another aspect, the present application provides an electronic device comprising the above MEMS device.

[0032] The MEMS device and the manufacturing method thereof and the electronic device according to the embodiments of the present application bond the first structure layer with the first MEMS structure formed therein and the second structure layer with the second MEMS structure formed therein, thereby reducing the area of the MEMS device, reducing the cost and the noise of the device, improving the anti-impact ability and the sensitivity of the device, and further improving the performance and the yield of the device. BRIEF DESCRIPTION OF DRAWINGS

[0033] The following drawings for the present application are hereby incorporated into this specification as part of the present application for understanding the present application. The drawings illustrate embodiments of the present application and a description thereof, serve to explain the principles of the present application.

[0034] In the drawings:

[0035] FIG. 1 shows a flow chart of a method for manufacturing a MEMS device according to an example embodiment of the present application;

[0036] FIGS. 2A-2G show cross-sectional schematic views of a MEMS device obtained by sequentially performing a method for manufacturing a MEMS device according to an example embodiment of the present application. DETAILED DESCRIPTION

[0037] The present application will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the application are shown. This application may, however, be embodied in different forms, and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided as non-limiting examples so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions are exaggerated for clarity. Identical reference numerals indicate identical elements throughout the several views.

[0038] It will be understood that when an element or layer is referred to as being "on" or "adjacent" or "connected" or "coupled" to another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer or one or more intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on," "directly adjacent," "directly connected" or "directly coupled" to another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0039] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, then a dependent element or feature described as "below" or "beneath" another element or feature is oriented "above" or "over" the other element or feature. Thus, the exemplary term "below" or "beneath" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] Embodiments of the application are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the application. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Thus, embodiments of the application should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle will, typically, have rounded or curved features and / or a gradient of implant concentration at its edges rather than a binary change between implanted and non-implanted regions. Similarly, an implanted region illustrated as a rectangle will, typically, have a region of some implant between the implanted region and the surface of the substrate upon which it is formed. Thus, the regions illustrated in the figures are schematic and are not intended to illustrate actual dimensions but are intended to be exemplary of the regions that are formed during the fabrication of a device. As used herein, the term "substantially" is used to describe an aspect that is expected to be identical to a true value within a margin of error. Further, the term "substantially" is used to describe an aspect that is not identical to a true value, but is sufficiently similar as to have little to no effect on the results obtained from a process, measurement, or test.

[0042] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and / or the

[0043] For a thorough understanding of the application, both the following detailed description and the structure will be presented in the following description in order to illustrate the technical solutions proposed by the application. The preferred embodiments of the application are described in detail as follows. However, in addition to these detailed descriptions, the application can have other implementations.

[0044] In the related art, in order to reduce the chip area, the IMU structure is generally formed by bonding to replace the planar layout. However, the bonding method in the related art generally needs to be bonded through an additional connection layer, and the MEMS structure is bonded with the connection layer respectively, and multiple bonding is needed, which increases the cost and increases the process steps, and the reliability of the device is also reduced.

[0045] In view of the existence of the foregoing technical problems, the application proposes a manufacturing method of a MEMS device, comprising:

[0046] Step S1, providing a first substrate and a second substrate, a first sacrificial layer is formed on the surface of the first substrate, and a second sacrificial layer is formed on the surface of the second substrate;

[0047] Step S2, forming a first structure layer on the first sacrificial layer, and forming a second structure layer on the second sacrificial layer, the first structure layer comprises a first structure region and a first bonding region located outside the first structure region, and the second structure layer comprises a second structure region corresponding to the first structure region and a second bonding region corresponding to the first bonding region;

[0048] Step S3, forming a first MEMS structure in the first structure region, and forming a second MEMS structure in the second structure region;

[0049] Step S4, etching to remove part of the first sacrificial layer to form a first cavity, and removing part of the second sacrificial layer to form a second cavity;

[0050] Step S5, bonding the first structure layer and the second structure layer through the first bonding region and the second bonding region, and the first cavity and the second cavity jointly form a cavity accommodating the first MEMS structure and the second MEMS structure.

[0051] The manufacturing method of the MEMS device of the application bonds the first structure layer with the first MEMS structure and the second structure layer with the second MEMS structure, which reduces the area of the MEMS device, reduces the cost and the noise of the device, and improves the impact resistance and sensitivity of the device, thereby improving the performance and yield of the device.

[0052] Embodiment one

[0053] The manufacturing method of the MEMS device of the present application will be described in detail below with reference to FIG. 1 and FIG. 2A-2G. FIG. 1 shows a flow chart of the manufacturing method of the MEMS device of an exemplary embodiment of the present application, and FIG. 2A-2G show cross-sectional schematic views of the MEMS device obtained by sequentially implementing the manufacturing method of the MEMS device of an exemplary embodiment of the present application. Exemplarily, the manufacturing method of the MEMS device of the present application includes the following steps:

[0054] First, step S1 is performed to provide a first substrate and a second substrate, wherein a first sacrificial layer is formed on a surface of the first substrate, and a second sacrificial layer is formed on a surface of the second substrate.

[0055] In one example, as shown in FIG. 2A and FIG. 2D, the first substrate 210 and the second substrate 220 are bulk silicon substrates, which can include at least one of the following materials: Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs, or other III / V compound semiconductors, or the first substrate 210 and the second substrate 220 can also include silicon-on-insulator (SOI), silicon-on-silicon-on-insulator (SSOI), silicon-on-silicon germanium-on-insulator (S-SiGeOI), silicon germanium-on-insulator (SiGeOI), germanium-on-insulator (GeOI), etc. Although several examples of the materials that can form the first substrate 210 and the second substrate 220 are described herein, any material that can serve as a semiconductor substrate falls within the spirit and scope of the present application.

[0056] In one example, as shown in FIG. 2A and FIG. 2D, the first sacrificial layer 213 is formed on the surface of the first substrate 210, and the second sacrificial layer 223 is formed on the surface of the second substrate 220. Exemplarily, various deposition processes commonly used in the art can be used to form the first sacrificial layer 213 and the second sacrificial layer 223, such as chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, or atomic layer deposition (ALD) method, etc., which are not limited by the present application. Exemplarily, the first sacrificial layer 213 and the second sacrificial layer 223 can include any of a number of dielectric materials, non-limiting examples of which include oxides, nitrides, and oxynitrides, and in particular oxides, nitrides, and oxynitrides of silicon, such as silicon oxide and carbon-doped silicon oxide (SiOC), etc.

[0057] In one example, as shown in FIG. 2A and FIG. 2D, a first insulating layer 211 is further formed on the surface of the first substrate 210, a first interconnection layer 212 is further formed on the first insulating layer 211, and a first sacrificial layer 213 is located on the first interconnection layer 212 and the first insulating layer 211; a second insulating layer 221 is further formed on the surface of the second substrate 220, a second interconnection layer 222 is further formed on the second insulating layer 221, and a second sacrificial layer 223 is located on the second interconnection layer 222 and the second insulating layer 221. Exemplarily, the first interconnection layer 212 and the second interconnection layer 222 serve as interconnections, such as connecting electrodes, etc.; wherein the material of the first interconnection layer 212 and the second interconnection layer 222 includes but is not limited to polysilicon. Exemplarily, the first insulating layer 211 and the second insulating layer 221 can include any one of a plurality of dielectric materials, non-limiting examples of which include oxides, nitrides, and oxynitrides, especially oxides, nitrides, and oxynitrides of silicon, such as silicon oxide and carbon-doped silicon oxide (SiOC), etc. Exemplarily, various deposition processes commonly used in the art can be used to form the first insulating layer 211, the first interconnection layer 212, the second insulating layer 221, and the second interconnection layer 222, such as chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, or atomic layer deposition (ALD) method, etc., which are not limited in the present application.

[0058] Next, step S2 is performed to form a first structure layer on the first sacrificial layer and a second structure layer on the second sacrificial layer, the first structure layer including a first structure region and a first bonding region located outside the first structure region, and the second structure layer including a second structure region corresponding to the first structure region and a second bonding region corresponding to the first bonding region.

[0059] In one example, as shown in FIG. 2A and FIG. 2D, a first structure layer 214 is formed on the first sacrificial layer 213, and a second structure layer 224 is formed on the second sacrificial layer 223, wherein the first structure layer 214 includes a first structure region and a first bonding region outside the first structure region, and the second structure layer 224 includes a second structure region corresponding to the first structure region and a second bonding region corresponding to the first bonding region. Exemplarily, the material of the first structure layer 214 and the second structure layer 224 includes but is not limited to polysilicon. Exemplarily, various deposition processes commonly used in the art can be used to form the first structure layer 214 and the second structure layer 224, such as chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, atomic layer deposition (ALD) method, selective epitaxial growth (SEG) method, etc., which are not limited in the present application. Exemplarily, as shown in FIG. 2A and FIG. 2D, the first structure layer 214 also partially extends into the first sacrificial layer 213 and contacts the first interconnection layer 212, and the second structure layer 224 also partially extends into the second sacrificial layer 223 and contacts the second interconnection layer 222, and also partially extends into the second insulating layer 221. Exemplarily, a metal pad electrically connected to an external circuit can also be formed on the first structure layer 214.

[0060] Then, step S3 is performed to form a first MEMS structure in the first structure region and a second MEMS structure in the second structure region.

[0061] In one example, as shown in FIG. 2B and FIG. 2E, various etching processes commonly used in the art can be used to etch the first structure layer 214 of the first structure region and the second structure layer 224 of the second structure region to form the first MEMS structure 215 and the second MEMS structure 225. The etching process can include conventional dry etching process and wet etching process, such as deep reactive ion etching, ion beam etching, plasma etching, laser ablation, or any combination of these methods, and a single etching process can be used, or more than one etching process can be used.

[0062] In one example, the first MEMS structure 215 includes a comb structure of a gyroscope, and the second MEMS structure 225 includes a comb structure of an accelerometer. The comb structure can also be referred to as a mass block. Taking the accelerometer as an example, when subjected to an acceleration load, the mass block will displace relative to the cantilever beam, and the displacement will be converted into an electrical signal output. Taking the gyroscope as an example, two moving mass blocks move in opposite directions. As long as an angular velocity parallel to the movement plane is applied, a Coriolis force perpendicular to the direction of movement of the mass block will be generated, causing the mass block to displace. The displacement is proportional to the size of the applied angular velocity. The displacement will cause a change in capacitance between the comb electrode of the mass block and the fixed electrode. Therefore, the angular velocity applied by the input part of the gyroscope is converted into an electrical parameter that can be detected by a dedicated circuit. The number and size of the comb structure can be set according to the process requirements of the accelerometer and the gyroscope.

[0063] In one example, as shown in FIG. 2B and FIG. 2E, before forming the first MEMS structure and the second MEMS structure, the method of the present application further includes etching the first structure layer 214 of the first structure region to a first thickness to lower the surface of the first structure region below the surface of the first bonding region, and etching the second structure layer 224 of the second structure region to a second thickness to lower the surface of the second structure region below the surface of the second bonding region. In subsequent steps, the first structure layer 214 and the second structure layer 224 are bonded by the first bonding region and the second bonding region, so the first structure region and the second structure region need to be etched to ensure that the first MEMS structure 215 and the second MEMS structure 225 have movable space in the direction perpendicular to the bonding surface. In this embodiment, the first thickness and the second thickness are in the range of 4-6 μm, for example, the first thickness and the second thickness can be 4 μm, 4.5 μm, 5 μm, 5.5 μm, or 6 μm, etc. In other embodiments, the first thickness and the second thickness can also be any other suitable range of values. The etching process can include traditional dry etching and wet etching, such as deep reactive ion etching, ion beam etching, plasma etching, laser ablation, or any combination of these methods. A single etching process can be used, or more than one etching process can be used. Before the etching step, the surfaces of the first structure region and the first bonding region are flush, and the surfaces of the second structure region and the second bonding region are flush, so that after the bonding step, the height difference between the surface of the first structure region and the surface of the first bonding region is the first thickness, and the height difference between the surface of the second structure region and the surface of the second bonding region is the second thickness.

[0064] Then, step S4 is performed to etch and remove part of the first sacrificial layer to form a first cavity and to etch and remove part of the second sacrificial layer to form a second cavity.

[0065] In one example, as shown in FIG. 2C and FIG. 2F, a wet etching process or a dry etching process can be employed to remove part of the first sacrificial layer 213 and part of the second sacrificial layer 223 to form the first cavity 216 and the second cavity 226. More specifically, a Buffer Oxide Etchant can be employed to remove part of the first sacrificial layer 213 and part of the second sacrificial layer 223, or a gaseous hydrogen fluoride (VHF) can be employed to remove part of the first sacrificial layer 213 and part of the second sacrificial layer 223. Illustratively, the first cavity 216 and the second cavity 226 are respectively configured to accommodate the first MEMS structure 215 and the second MEMS structure 225 and to provide movable space.

[0066] Finally, step S5 is performed to bond the first structure layer and the second structure layer through the first bonding region and the second bonding region, and the first cavity and the second cavity jointly form a cavity to accommodate the first MEMS structure and the second MEMS structure.

[0067] In one example, as shown in FIG. 2G, the first structure layer 214 and the second structure layer 224 are bonded through the first bonding region and the second bonding region, and the first cavity 216 and the second cavity 226 jointly form a cavity to accommodate the first MEMS structure 215 and the second MEMS structure 225. In this embodiment, the first structure layer 214 and the second structure layer 224 are bonded through the first bonding region and the second bonding region by a hybrid bonding process. Compared with a related bonding process which requires forming a bump or a bonding metal ring, the hybrid bonding process has the following advantages: the hybrid bonding process has a lower temperature, generally lower than or equal to 400 degrees Celsius, while the related bonding process has a temperature of 900 degrees Celsius to 1200 degrees Celsius; the hybrid bonding process has a shorter time, generally between 15 minutes to 25 minutes, while the related bonding process generally needs 120 minutes to 160 minutes; the hybrid bonding process has a higher alignment accuracy, 20 nm-300 nm, while the related bonding process has an alignment accuracy of about 15 μm; the hybrid bonding process has a higher vacuum degree, which can reach 10 -8 Pa, while the related bonding process generally has a vacuum degree of 10 -6 Pa. Illustratively, the cavity jointly formed by the first cavity 216 and the second cavity 226 is a vacuum cavity, and the vacuum degree of the cavity is less than 10 -8Pa, a higher vacuum degree can effectively improve the quality factor of the device (e.g., a gyroscope and an accelerometer), reduce the mechanical thermal noise, and improve the zero bias stability. Optionally, the vacuum degree of the cavity can be 10 -8.1 Pa, 10 -8.5 Pa, 10 -8.6 Pa, 10 -8.8 Pa, or 10 -9 Pa, etc. Exemplarily, a bonding layer (not shown) can also be formed on the first bonding region and the second bonding region, respectively, and the material of the bonding layer includes but is not limited to silicon nitride, silicon dioxide, silicon carbide, etc. The first structure layer 214 and the second structure layer 224 are bonded by the bonding layer through a hybrid bonding process.

[0068] In one example, the first structure layer 214 and the second structure layer 224 are bonded to form a MEMS device, and the first MEMS structure and the second MEMS structure are arranged in a top-down manner. Compared with the planar layout, the area of the MEMS device in the present application is smaller, the integration is higher, and the impact resistance is stronger. At the same time, the metal wiring can be reduced, thereby reducing the parasitic capacitance, reducing the noise, and improving the sensitivity of the device. Exemplarily, only one bonding step is required in the present application, and the first MEMS structure and the second MEMS structure are located in the same cavity, which can improve the reliability of the device, reduce the process steps, and reduce the cost.

[0069] The key steps of the method for manufacturing the MEMS device of the present application have been described so far. The complete manufacturing of the MEMS device can also include other steps, which are not described here. It is worth mentioning that the above step sequence can be adjusted without conflict.

[0070] In summary, the method for manufacturing the MEMS device of the embodiment of the present application bonds the first structure layer with the first MEMS structure and the second structure layer with the second MEMS structure, which reduces the area of the MEMS device, reduces the cost and the noise of the device, and improves the impact resistance and the sensitivity of the device, thereby improving the performance and the yield of the device. Exemplarily, the cavity is a vacuum cavity, and a higher vacuum degree can effectively improve the quality factor of the device, reduce the mechanical thermal noise, and improve the zero bias stability.

[0071] Embodiment Two

[0072] The present application also provides a MEMS device manufactured by the method in the foregoing embodiment one.

[0073] Next, the MEMS device of the present application will be described in detail with reference to FIG. 2G. Exemplarily, the MEMS device of the present application includes:

[0074] a first substrate 210;

[0075] a first sacrificial layer 213 on the first substrate 210, the first sacrificial layer 213 having a first cavity 216 formed therein;

[0076] a first structural layer 214 on the first sacrificial layer 213, the first structural layer 214 including a first structural region and a first bonding region outside the first structural region, and the first MEMS structure 215 being formed in the first structural region;

[0077] a second structural layer 224 on the first structural layer 214, the second structural layer 224 including a second structural region corresponding to the first structural region and a second bonding region corresponding to the first bonding region, and the second MEMS structure 225 being formed in the second structural region;

[0078] a second sacrificial layer 223 on the second structural layer 224, the second sacrificial layer 223 having a second cavity 226 formed therein;

[0079] a second substrate 220 on the second sacrificial layer 223;

[0080] wherein the first cavity 216 and the second cavity 226 together form a cavity accommodating the first MEMS structure and the second MEMS structure.

[0081] In one example, the first substrate 210 and the second substrate 220 are bulk silicon substrates, which can include at least one of the following mentioned materials: Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs, or other III / V compound semiconductors, or the first substrate 210 and the second substrate 220 can also include silicon-on-insulator (SOI), silicon-on-silicon stacked-on-insulator (SSOI), silicon germanium-on-insulator (SiGeOI), or germanium-on-insulator (GeOI), etc. Although several examples of materials that can form the first substrate 210 and the second substrate 220 are described herein, any material that can serve as a semiconductor substrate falls within the spirit and scope of the present application.

[0082] In one example, as shown in FIG. 2G, the first substrate 210 and the first sacrificial layer 213 are further formed with a first insulating layer 211 and a first interconnect layer 212, and the second substrate 220 and the second sacrificial layer 223 are further formed with a second insulating layer 221 and a second interconnect layer 222. Exemplarily, the first interconnect layer 212 and the second interconnect layer 222 serve as interconnects, such as electrodes and the like; wherein the material of the first interconnect layer 212, the second interconnect layer 222, the first structural layer 214 and the second structural layer 224 includes but is not limited to polysilicon. Exemplarily, the first insulating layer 211, the second insulating layer 221, the first sacrificial layer 213 and the second sacrificial layer 223 can include any one of a plurality of dielectric materials, non-limiting examples of which include oxides, nitrides and oxynitrides, especially oxides, nitrides and oxynitrides of silicon, such as silicon oxide and carbon-doped silicon oxide (SiOC) and the like.

[0083] In one example, as shown in FIG. 2G, the surface of the first structural region towards the second MEMS structure 225 is lower than the surface of the first bonding region towards the second MEMS structure 225 by 4-6 μιη; the surface of the second structural region towards the first MEMS structure 215 is higher than the surface of the second bonding region towards the first MEMS structure 215 by 4-6 μιη, for example, the surface of the second structural region towards the first MEMS structure 215 can be higher than the surface of the second bonding region towards the first MEMS structure 215 by 4 μιη, 4.5 μιη, 5 μιη, 5.5 μιη or 6 μιη and the like, so as to provide movable space for the first MEMS structure 215 and the second MEMS structure 225 in the direction perpendicular to the bonding surface.

[0084] In one example, the first MEMS structure 215 includes a comb structure of a gyroscope, and the second MEMS structure 225 includes a comb structure of an accelerometer.

[0085] In one example, the first structural layer 214 and the second structural layer 224 are bonded together through the first bonding region and the second bonding region. In this embodiment, the first structural layer 214 and the second structural layer 224 are bonded through the first bonding region and the second bonding region by a hybrid bonding process. Exemplarily, a bonding layer (not shown) can be further formed on the first bonding region and the second bonding region respectively, the material of the bonding layer includes but is not limited to silicon nitride, silicon dioxide, silicon carbide and the like, and the first structural layer 214 and the second structural layer 224 are bonded through the bonding layer by the hybrid bonding process.

[0086] In one example, the cavity formed by the first cavity 216 and the second cavity 226 is a vacuum cavity, and the vacuum degree of the cavity is less than 10 -8Pa, the higher vacuum degree can effectively improve the quality factor of the device (e.g., a gyroscope and an accelerometer), reduce the mechanical thermal noise, and improve the zero bias stability. Optionally, the vacuum degree of the cavity can be 10 -8.1 Pa, 10 -8.5 Pa, 10 -8.6 Pa, 10 -8.8 Pa, or 10 -9 Pa, etc.

[0087] The structure of the MEMS device of the present application is introduced above, and other component structures can also be included in the complete device, which are not described herein.

[0088] In summary, the MEMS device of the embodiment of the present application is manufactured by the above method, the first structure layer with the first MEMS structure and the second structure layer with the second MEMS structure are bonded, the area of the MEMS device is reduced, the cost and the device noise are reduced, and the impact resistance and the sensitivity of the device are improved, thereby improving the device performance and the yield. Exemplarily, the cavity is a vacuum cavity, and the higher vacuum degree can effectively improve the quality factor of the device, reduce the mechanical thermal noise, and improve the zero bias stability.

[0089] Embodiment Three

[0090] Another embodiment of the present application further provides an electronic device including the MEMS device described above.

[0091] The electronic device of the embodiment can be a mobile phone, a tablet computer, a notebook computer, a netbook, a game console, a television, a VCD, a DVD, a navigator, a camera, a video camera, a recording pen, an MP3, an MP4, a PSP, or any other electronic product or device, and can also be any intermediate product including the MEMS device. The electronic device of the embodiment of the present application has better performance due to the use of the MEMS device described above.

[0092] Although a plurality of embodiments are described herein, it should be understood that various other modifications and embodiments can be conceived by those skilled in the art, which will fall within the spirit and scope of the concept disclosed by the present application. More particularly, various modifications and changes can be made in the arrangement and / or component parts of the subject matter in the scope of the present application disclosure, the accompanying drawings, and the appended claims. In addition to the modifications and changes of the component parts and / or arrangement, the use of alternative ways is also an obvious choice for those skilled in the art.

Claims

1. A method of manufacturing a MEMS device, characterized by, The method comprises: providing a first substrate and a second substrate, a first sacrificial layer is formed on a surface of the first substrate, and a second sacrificial layer is formed on a surface of the second substrate; forming a first structure layer on the first sacrificial layer, the first structure layer comprising a first structure region and a first bonding region outside the first structure region, and forming a second structure layer on the second sacrificial layer, the second structure layer comprising a second structure region corresponding to the first structure region and a second bonding region corresponding to the first bonding region; forming a first MEMS structure in the first structure region and a second MEMS structure in the second structure region; etching to remove part of the first sacrificial layer to form a first cavity and etching to remove part of the second sacrificial layer to form a second cavity; bonding the first structure layer and the second structure layer through the first bonding region and the second bonding region, and the first cavity and the second cavity jointly forming a cavity accommodating the first MEMS structure and the second MEMS structure.

2. The manufacturing method according to claim 1, characterized by, The first structure layer and the second structure layer are bonded through the first bonding region and the second bonding region by a mixed bonding process.

3. The production method according to claim 1, characterized by Before forming the first MEMS structure and the second MEMS structure, the method further comprises: etching the first structure layer of the first structure region to a first thickness so that the surface of the first structure region is lower than the surface of the first bonding region, and etching the second structure layer of the second structure region to a second thickness so that the surface of the second structure region is lower than the surface of the second bonding region.

4. The production method according to claim 3, characterized by The first thickness and the second thickness range from 4 μm to 6 μm.

5. The production method according to claim 1, characterized by The cavity is a vacuum cavity, and a vacuum degree of the cavity is less than 10 -8 Pa.

6. The production method according to claim 1, characterized by A first insulating layer is further formed on the surface of the first substrate, a first interconnection layer is further formed on the first insulating layer, and the first sacrificial layer is located on the first interconnection layer and the first insulating layer; a second insulating layer is further formed on the surface of the second substrate, a second interconnection layer is further formed on the second insulating layer, and the second sacrificial layer is located on the second interconnection layer and the second insulating layer; The first structure layer partially extends into the first sacrificial layer and is in contact with the first interconnection layer, and the second structure layer partially extends into the second sacrificial layer and is in contact with the second interconnection layer.

7. The production method according to any one of claims 1 to 6, characterized by, The first MEMS structure comprises a comb structure of a gyroscope, and the second MEMS structure comprises a comb structure of an accelerometer.

8. A MEMS device, characterized by Comprise: a first substrate; a first sacrificial layer located on the first substrate, a first cavity being formed in the first sacrificial layer; a first structure layer located on the first sacrificial layer, comprising a first structure region and a first bonding region outside the first structure region, and a first MEMS structure being formed in the first structure region; a second structure layer located on the first structure layer, comprising a second structure region corresponding to the first structure region and a second bonding region corresponding to the first bonding region, and a second MEMS structure being formed in the second structure region; a second sacrificial layer on the second structural layer, a second cavity being formed in the second sacrificial layer; a second substrate on the second sacrificial layer; wherein the first cavity and the second cavity together form a cavity accommodating the first MEMS structure and the second MEMS structure.

9. The MEMS device of claim 8, wherein, a surface of the first structural region facing the second MEMS structure is lower than a surface of the first bonding region facing the second MEMS structure by 4-6 pm; a surface of the second structural region facing the first MEMS structure is higher than a surface of the second bonding region facing the first MEMS structure by 4-6 pm.

10. The MEMS device of claim 8, wherein, The cavity is a vacuum cavity, and a vacuum degree of the cavity is less than 10 -8 Pa.

11. An electronic device, comprising: The electronic device comprises the MEMS device of any one of claims 8-10.

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