MEMS device and preparation method thereof, and electronic device

Abstract

The invention discloses an MEMS device and a preparation method thereof, and an electronic device. The MEMS device comprises a semiconductor substrate; the movable structure is arranged on the semiconductor substrate and comprises a supporting part and a cantilever part, the cantilever part and the semiconductor substrate are arranged in a spaced mode in the direction perpendicular to the surface of the semiconductor substrate, and the supporting part is connected between the semiconductor substrate and the cantilever part; and the stop block is arranged on the semiconductor substrate and is opposite to the cantilever part in position. By transferring the stop block from the movable structure to one side of the semiconductor substrate, the preparation precision of the stop block can be controlled in the preparation process of the stop block, so that the preparation precision of the stop block is improved, and the reliability, the service life and the yield of a product are improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a MEMS device and a preparation method thereof, and an electronic device. Background Art

[0002] MEMS (Micro-Electro-Mechanical System) refers to a micro-system that integrates mechanical components, drive components, optical systems, and electronic control systems. MEMS sensors, with their advantages of small size, low power consumption, and mass production, have found widespread application in smartphones, tablets, game consoles, automobiles, drones, electronics, aerospace, and other fields.

[0003] MEMS sensors include a movable structure and a stopper positioned on the movable structure. The stopper is used to limit excessive movement of the movable structure, which could damage the structure, and to prevent large-area contact between the movable structure and the fixed structure, which could cause engagement. However, the manufacturing precision of the stopper in related art is low, resulting in reduced product reliability, service life, and yield. Summary of the Invention

[0004] The Summary of the Invention introduces a series of simplified concepts that will be further described in the Detailed Description of the Invention. The Summary of the Invention is not intended to limit the key features and essential features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] In order to solve the existing problems, a first aspect of an embodiment of the present invention provides a MEMS device, which includes:

[0006] semiconductor substrates;

[0007] A dielectric layer disposed on a surface of a semiconductor substrate;

[0008] A conductive layer is provided on the surface of the dielectric layer, and the conductive layer has a stopper protruding toward a side away from the semiconductor substrate;

[0009] The movable structure is arranged on the conductive layer, and the movable structure includes a support portion and a cantilever portion, wherein the cantilever portion is opposite to the stop block in a direction perpendicular to the surface of the semiconductor substrate, and the support portion is connected between the conductive layer and the cantilever portion.

[0010] In some embodiments of the present application, the MEMS device further includes:

[0011] A first boss is provided on a semiconductor substrate, wherein a dielectric layer covers the first boss and a second boss is conformally formed above the first boss; a conductive layer covers the second boss and a stopper is conformally formed above the second boss.

[0012] In some embodiments of the present application, the conductive layer includes a fixed structure positioned opposite to and spaced apart from the cantilever portion, and a conductive pad electrically insulated from the fixed structure. The fixed structure is conformally formed with a stop block above the second boss, and the support portion is connected to the conductive pad.

[0013] In some embodiments of the present application, there are multiple stop blocks, and the tops of the multiple stop blocks are at the same horizontal height.

[0014] In some embodiments of the present application, the MEMS device includes a MEMS inertial device, and the movable structure includes a movable comb structure of the MEMS inertial device.

[0015] A second aspect of an embodiment of the present invention provides a method for manufacturing a MEMS device, the method comprising:

[0016] providing a semiconductor substrate;

[0017] forming a dielectric layer on a surface of a semiconductor substrate;

[0018] forming a conductive layer on the surface of the dielectric layer, wherein the conductive layer has a stopper protruding toward a side away from the semiconductor substrate;

[0019] A movable structure is formed on the conductive layer. The movable structure includes a support portion and a cantilever portion. The cantilever portion is opposite to the stop block in a direction perpendicular to the surface of the semiconductor substrate. The support portion is connected between the conductive layer and the cantilever portion.

[0020] In some embodiments of the present application, before forming the dielectric layer on the surface of the semiconductor substrate, the preparation method further includes:

[0021] forming a first protrusion on a semiconductor substrate;

[0022] The dielectric layer covers the first boss and a second boss is formed conformally above the first boss. The conductive layer covers the second boss and a stop block is formed conformally above the second boss.

[0023] In some embodiments of the present application, forming a first protrusion on a semiconductor substrate includes:

[0024] forming a dielectric material layer of a predetermined thickness on a semiconductor substrate;

[0025] The dielectric material layer is etched to form a first protrusion.

[0026] In some embodiments of the present application, the conductive layer includes a conductive pad electrically insulated from the stopper;

[0027] A movable structure is formed on the conductive layer, comprising:

[0028] forming a sacrificial layer on the conductive layer;

[0029] etching the sacrificial layer to form a groove in the sacrificial layer that exposes at least the conductive pad;

[0030] forming a structural layer on the sacrificial layer and in the groove;

[0031] patterning the structural layer to form a movable structure, wherein a portion of the structural layer located in the groove forms a support portion;

[0032] The sacrificial layer is removed.

[0033] A third aspect of an embodiment of the present invention provides an electronic device, which includes any one of the above-mentioned MEMS devices.

[0034] According to the MEMS device, preparation method thereof, and electronic device provided by the present invention, by transferring the stop block from the movable structure to the conductive layer close to the semiconductor substrate side, it is beneficial to control the preparation accuracy of the stop block during the preparation process of the stop block, thereby improving the preparation accuracy of the stop block, which is beneficial to improving the reliability, service life and yield of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following drawings of the present invention are incorporated herein as part of the present invention for understanding the present invention. The drawings show embodiments of the present invention and the description thereof is used to explain the principle of the present invention.

[0036] In the attached figure:

[0037] Figure 1 A cross-sectional schematic diagram of a MEMS device according to a specific embodiment of the present invention is shown;

[0038] Figure 2 A schematic flow chart showing a method for preparing a MEMS device according to a specific embodiment of the present invention is shown;

[0039] Figures 3A to 3I A cross-sectional schematic diagram showing various steps in a method for preparing a MEMS device according to a specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0040] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0041] It should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals throughout represent like elements.

[0042] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, 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, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Thus, a first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part without departing from the teachings of the present invention.

[0043] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein for convenience of description to describe the relationship of one element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the drawings is flipped, then the elements or features described as "under" or "beneath" or "beneath" the other elements will be oriented as "over" the other elements or features. Thus, the exemplary terms "under" and "under" may include both the upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0044] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. When used herein, the singular forms "a", "an", and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0045] Example 1

[0046] refer to Figure 1 , an embodiment of the present invention provides a MEMS device, the MEMS device mainly comprising:

[0047] a semiconductor substrate 101;

[0048] A dielectric layer 110 disposed on a surface of the semiconductor substrate 101;

[0049] A conductive layer 107 is disposed on the surface of the dielectric layer 110 , and the conductive layer 107 has a stopper 104 protruding toward a side away from the semiconductor substrate 101 ;

[0050] The movable structure 113 is arranged on the conductive layer 107, and the movable structure 113 includes a supporting portion 103 and a cantilever portion 102, wherein the cantilever portion 102 is opposite to the stop block 104 in a direction perpendicular to the surface of the semiconductor substrate 101, and the supporting portion 103 is connected between the conductive layer 107 and the cantilever portion 102.

[0051] The specific technical effects and principles are as follows: In the related art, the stop block is set on the movable structure, and the specific processing method is: before forming the structural layer, a flattened sacrificial layer is first formed, and then the sacrificial layer is etched to form a groove for pre-forming the stop block, and then a structural layer is formed on the sacrificial layer and in the groove, and the part of the structural layer located in the groove constitutes the stop block; and then the sacrificial layer is removed. However, in this method, the stop block is prepared based on the groove formed by etching the sacrificial layer. Due to the low preparation accuracy during the etching process to form the groove, it is impossible to control the depth of the groove corresponding to different stop blocks to be consistent, resulting in poor height uniformity of different stop blocks. Furthermore, the critical dimension (CD) of the stop block is generally less than 10 microns to prevent large-area contact between the movable structure and the fixed structure. The related art is also unable to monitor the critical dimension of the stop block online. In addition, if an abnormality occurs during the process of etching the wafer to form the groove, it is difficult to solve it by rework, and the abnormality remediation is difficult.

[0052] In the above embodiments of the present application, reference is made to Figure 1 The stopper 104 is transferred from the movable structure 113 to the conductive layer 107 on the side close to the semiconductor substrate 101. Specifically, before preparing the movable structure 113, a conformal deposition process, a patterning process, or the like can be used to form a conductive layer 107 having the stopper 104 on the semiconductor substrate 101. A process that can monitor the height and critical dimensions of the stopper 104 online is preferably selected, thereby eliminating the need to use etching to form grooves. This facilitates controlling the preparation accuracy of the stopper 104 during the preparation of the stopper 104, ensuring a high degree of height uniformity among different stopper 104s, and improving the uniformity of the stopper 104 within or between wafers, thereby avoiding the problem of height differences of the stopper 104 caused by the etching groove process. Furthermore, it is convenient to control the critical dimensions of the stopper 104 online, thereby improving the preparation accuracy of the stopper 104, thereby improving the reliability, service life, and yield of the product and ensuring product quality. Furthermore, since etching is no longer used to form the grooves for the stopper 104, a process with less difficulty in repairing the stopper 104 can be selected, thereby avoiding the difficulty in repairing any anomalies that occur during the groove formation process. Furthermore, the above method requires only a simple adjustment of the process sequence to transfer the stopper 104 from the side where the movable structure 113 is formed to the conductive layer 107 on the side closer to the semiconductor substrate 101, without adding any additional process steps and thus without increasing costs.

[0053] Below, reference Figure 1 The MEMS device according to the embodiment of the present invention is described in detail.

[0054] For example, the semiconductor substrate 101 may 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 semiconductor substrate 101 may include silicon-on-insulator (SOI), stacked silicon-on-insulator (SSOI), stacked silicon-germanium-on-insulator (S-SiGeOI), silicon-germanium-on-insulator (SiGeOI), or germanium-on-insulator (GeOI). Although several examples of materials that can form the semiconductor substrate 101 are described herein, any material that can be used as the semiconductor substrate 101 falls within the spirit and scope of the present invention.

[0055] The movable structure 113 may be made of any conductive material. For example, the movable structure 113 may be made of at least one of the following materials: Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs, or other III / V compound semiconductors, including multilayer structures of these semiconductors.

[0056] Exemplary, reference Figure 1 The cantilever portion 102 is positioned opposite the stop block 104 in a direction perpendicular to the surface of the semiconductor substrate 101. That is, the cantilever portion 102 has a free end that is cantilevered. When the MEMS device moves, the cantilever portion 102 can move toward or away from the semiconductor substrate 101. The cantilever portion 102 is positioned opposite the conductive layer 107, and a capacitor is formed between the cantilever portion 102 and the conductive layer 107. Therefore, when the MEMS device moves, the capacitance between the movable structure 113 and between the movable structure 113 and the conductive layer 107 changes, thereby converting the motion parameters into electrical parameters.

[0057] Exemplary, reference Figure 1 A fixed structure 106 that forms a capacitor with the cantilever portion 102 can be provided on the conductive layer 107. Specifically, the fixed structure 106 and the cantilever portion 102 are positioned relative to each other and are spaced apart. Therefore, when the MEMS device moves, the free end of the cantilever portion 102 can move, thereby changing the capacitance value of the capacitor formed by the cantilever portion 102 and the fixed structure 106, causing the capacitance value of the capacitor of the MEMS device to change, thereby realizing the conversion of motion parameters into electrical parameters.

[0058] Exemplary, reference Figure 1 The cantilever portion 102 and the fixed structure 106 can be the movable plate and the fixed plate of the capacitor respectively. The movable plate and the fixed plate are positioned relative to each other and are spaced apart. Therefore, when the movable plate moves with the MEMS device, the distance between the movable plate and the fixed plate can be changed, thereby changing the capacitance value of the capacitor.

[0059] refer to Figure 1 Regarding the number of stop blocks 104, there can be one or more. In some embodiments, there are multiple stop blocks 104, and the tops of the multiple stop blocks 104 are at the same horizontal height, thereby ensuring the uniformity of the height of the stop blocks 104 between wafers and within a wafer. Therefore, when the multiple stop blocks 104 stop the movable structure 113, it is beneficial for the multiple stop blocks 104 to collide with the movable structure 113 at the same time, thereby increasing the contact area between the movable structure 113 and the stop blocks 104 during the collision, reducing the collision stress, and reducing the risk of damage to the movable structure 113 or the stop blocks 104.

[0060] When setting the stop block 104, various methods can be used, and some methods are exemplarily introduced below.

[0061] Exemplary, reference Figure 1The MEMS device further includes: a first boss 108 disposed on the semiconductor substrate 101, wherein a dielectric layer 110 covers the first boss 108 and a second boss 109 is conformally formed above the first boss 108, and a conductive layer 107 covers the second boss 109 and a stopper 104 is conformally formed above the second boss 109. Specifically, the dielectric layer 110 partially covers the surface of the semiconductor substrate 101 and partially covers the upper surface and sidewalls of the first boss 108, so that the second boss 109 is conformally formed above the first boss 108 based on the outer convex profile of the first boss 108. The conductive layer 107 partially covers the surface of the dielectric layer 110 and partially covers the upper surface and sidewalls of the second boss 109, so that the stopper 104 is conformally formed above the second boss 109 based on the outer convex profile of the second boss 109.

[0062] Through the above method, the height and critical dimensions of the first protrusion 108 can be controlled during the formation process. Subsequently, the height and critical dimensions of the second protrusion 109 on the dielectric layer 110 can be indirectly controlled by controlling the deposition thickness of the dielectric layer 110. Furthermore, the height and critical dimensions of the stopper 104 can be indirectly controlled by controlling the deposition thickness of the conductive layer 107, thus achieving online control of the height and critical dimensions of the stopper 104.

[0063] Exemplary, reference Figure 1 A first boss 108 is provided on the semiconductor substrate 101, and the number of the first bosses 108 is equal to the number of the stop blocks 104. A plurality of first bosses 108 are arranged at intervals on the semiconductor substrate 101. The dielectric layer 110 covers at least the surface of the semiconductor substrate 101 and the side surfaces and upper surfaces of the first bosses 108, that is, the dielectric layer 110 completely covers the first bosses 108. The dielectric layer 110 is also formed with a second boss 109 above the first boss 108 in a conformal manner. The second boss 109 is located above the first boss 108 and its shape is related to the shape of the first boss 108. Exemplarily, the top view profile of the second boss 109 can surround the top view profile of the first boss 108 or coincide with the top view profile of the first boss 108, so that the critical size, profile shape and height of the second boss 109 can be indirectly controlled by the critical size, profile shape and height of the first boss 108 and the deposition thickness of the dielectric layer 110.

[0064] Exemplary, reference Figure 1The conductive layer 107 at least covers the surface of the dielectric layer 110 and the side and top surfaces of the second protrusion 109, that is, the conductive layer 107 completely covers the second protrusion 109. Furthermore, the conductive layer 107 conformally forms a stopper 104 above the second protrusion 109. The stopper 104 is located above the second protrusion 109 and its shape is related to the shape of the second protrusion 109. For example, the top view profile of the stopper 104 may encompass the top view profile of the second protrusion 109 or coincide with the top view profile of the second protrusion 109. Thus, the critical dimensions, profile shape, and height of the stopper 104 can be indirectly controlled by the critical dimensions, profile shape, and height of the second protrusion 109 and the deposition thickness of the conductive layer 107.

[0065] Exemplary, reference Figure 1 The conductive layer 107 includes a fixed structure 106 positioned opposite and spaced from the cantilever portion 102, and a conductive pad 105 electrically insulated from the fixed structure 106. The fixed structure 106 has a stopper 104 formed on top of the second boss 109, and the support portion 103 is connected to the conductive pad 105. A capacitor of the MEMS device can be formed between the fixed structure 106 and the cantilever portion 102. In this case, the fixed structure 106 and the stopper 104 can be patterned based on the same conductive layer 107, forming an integrated structure with the stopper 104, thereby improving the reliability of the connection between the stopper 104 and the fixed structure 106. Simultaneously, the conductive layer 107 can be patterned to form the conductive pad 105, which is located on the same layer as the fixed structure 106 and is electrically insulated from each other. This facilitates the electrical connection of the movable structure 113 to the pads of the semiconductor substrate 101, thereby enabling the extraction of electrical signals from the movable structure 113.

[0066] The conductive layer 107 may be made of any conductive material. For example, the conductive layer 107 may be made of at least one of the following materials: Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs, or other III / V compound semiconductors, including multilayer structures of these semiconductors.

[0067] Exemplarily, the MEMS device may include a MEMS inertial device, in which case the movable structure 113 may include a movable comb-tooth structure of the MEMS inertial device. Exemplarily, the MEMS inertial device may include a MEMS gyroscope, in which case the movable structure 113 is the movable comb-tooth structure of the MEMS gyroscope. Exemplarily, the MEMS inertial device may include a MEMS accelerometer, in which case the movable structure 113 is the movable comb-tooth structure of the MEMS accelerometer. The number, size, etc. of the movable comb-tooth structures may be set according to the process requirements of the accelerometer and gyroscope. Exemplarily, a MEMS gyroscope may also be used in combination with a MEMS accelerometer to reduce cost and volume.

[0068] Exemplarily, the fixed structure 106 may also be a fixed comb-tooth structure in a MEMS inertial device, and the fixed comb-tooth structure and the movable comb-tooth structure are spaced apart and matched to form a capacitor in the MEMS device.

[0069] Exemplary, reference Figure 1 A grounding hole may be provided through the dielectric layer 110. The conductive layer 107 includes a grounding conductive layer 112 electrically insulated from the fixed structure 106. The grounding conductive layer 112 at least covers the sidewalls and bottom of the grounding hole and is electrically connected to the semiconductor substrate 101. Figure 1 The MEMS device may further include a grounding structure 111 , which extends into a grounding hole in the dielectric layer 110 and is electrically connected to the grounding conductive layer 112 , thereby leading out a ground signal from the semiconductor substrate 101 .

[0070] Thus far, the main structure of the MEMS device according to one embodiment of the present invention has been completed. It can be understood that the MEMS device of this embodiment not only includes the above structure, but also may include other required structures, which are all included in the scope of the MEMS device of this embodiment.

[0071] Example 2

[0072] refer to Figure 2 Another embodiment of the present invention further provides a method for preparing a MEMS device, the method mainly comprising:

[0073] In S201 , a semiconductor substrate is provided;

[0074] In S202, a dielectric layer is formed on the surface of the semiconductor substrate;

[0075] In S203, a conductive layer is formed on the surface of the dielectric layer, wherein the conductive layer has a stopper protruding toward a side away from the semiconductor substrate;

[0076] In S204 , a movable structure is formed on the conductive layer, the movable structure including a support portion and a cantilever portion, wherein the cantilever portion is opposite to the stop block in a direction perpendicular to the surface of the semiconductor substrate, and the support portion is connected between the conductive layer and the cantilever portion.

[0077] The specific technical effects and principles are as follows: Compared with the related art, this embodiment forms a stop block on the semiconductor substrate, so that the stop block can be prepared by selecting a process with higher preparation precision, which is convenient for online control of the key dimensions of the stop block, thereby improving the preparation precision of the stop block, which is conducive to improving the reliability, service life and yield of the product and ensuring the product quality. The height uniformity of different stop blocks is made higher, and the uniformity of the stop blocks within the wafer or between wafers is improved, thereby avoiding the problem of stop block height differences caused by the groove etching process. For details, please refer to the corresponding part of the description of Example 1, which will not be repeated here.

[0078] Below, reference Figures 3A to 3I The method for manufacturing the MEMS device according to the embodiment of the present invention is described in detail.

[0079] refer to Figure 3A , providing a semiconductor substrate 301. Regarding the type of the semiconductor substrate 301, reference may be made to the corresponding description in the embodiment, which will not be repeated here.

[0080] In some embodiments, reference Figures 3A to 3B Before forming the dielectric layer 304 on the surface of the semiconductor substrate 301, the preparation method may include: forming a first protrusion 303 on the semiconductor substrate 301. Figure 3C , so that after the dielectric layer 304 is formed on the surface of the semiconductor substrate 301, the dielectric layer 304 also covers the first protrusion 303 and a second protrusion 305 is formed on the first protrusion 303. Figure 3D After the conductive layer 307 is formed on the surface of the dielectric layer 304 , the conductive layer 307 covers the second boss 305 and a stop block 308 is conformally formed above the second boss 305 .

[0081] In the above embodiment, the height and critical dimensions of the first protrusion 303 can be controlled during the formation process. Subsequently, the height and critical dimensions of the second protrusion 305 on the dielectric layer 304 can be indirectly controlled by controlling the deposition thickness of the dielectric layer 304. Furthermore, the height and critical dimensions of the stopper 308 can be indirectly controlled by controlling the deposition thickness of the conductive layer 307, thereby achieving online control of the height and critical dimensions of the stopper 308.

[0082] For example, various methods can be used to form the first protrusion 303 on the semiconductor substrate 301. In a preferred embodiment, a process with high control precision can be selected. Some methods are described below as examples.

[0083] Exemplarily, forming the first protrusion 303 on the semiconductor substrate 301 may include:

[0084] refer to Figure 3A , forming a dielectric material layer 302 of a set thickness on the semiconductor substrate 301;

[0085] refer to Figure 3B , the dielectric material layer 302 is etched to form a first protrusion 303 .

[0086] Among them, in the process of forming the dielectric material layer 302 of a set thickness, the dielectric material layer 302 of a set thickness can be formed by controlling the deposition time and deposition rate of the dielectric material layer 302. Thereafter, when the dielectric material layer 302 is graphically processed to obtain the pattern of the first boss 303, it can be ensured that the top of the obtained first boss 303 is at the same horizontal height, which is conducive to improving the height uniformity of the first boss 303 within and between sheets, and is conducive to finally improving the height uniformity of the stop block 308 within and between sheets.

[0087] For example, the dielectric material layer 302 may be etched using processes such as, but not limited to, dry etching or wet etching. In a preferred embodiment, a highly conformal etching process may be selected to form the first protrusion 303, thereby facilitating control of the critical dimensions and profile of the stopper 308 formed.

[0088] For example, when the dielectric layer 304 is formed on the surface of the semiconductor substrate 301 and the first protrusion 303 , the dielectric layer 304 may be deposited to a target thickness according to subsequent needs of the dielectric layer 304 .

[0089] Exemplary, reference Figure 3C A grounding hole 306 may be formed through the dielectric layer 304 to serve as a grounding structure formation area for subsequently leading out the semiconductor substrate 301 .

[0090] Exemplary, reference Figure 3D , the conductive layer 307 may include a conductive pad 309 electrically insulated from the stopper 308. For example, a conductive material layer may be formed on the dielectric layer 304 first, and then the conductive material layer may be patterned and etched to form the conductive pad 309, the stopper 308, and the fixing structure 310 serving as one of the plates of the capacitor on the same layer. For example, referring to Figure 3DThe conductive layer 307 further includes a grounding conductive layer 311 , which is electrically insulated from the fixed structure 310 . The grounding conductive layer 311 covers the sidewalls and bottom of the grounding hole 306 , thereby being electrically connected to the semiconductor substrate 301 .

[0091] Exemplary, reference Figures 3E to 3I , forming the movable structure 318 on the conductive layer 307 may include the following steps:

[0092] refer to Figure 3E , forming a sacrificial layer 312 on the conductive layer 307;

[0093] refer to Figure 3F , etching the sacrificial layer 312 to form at least a groove 313 exposing the conductive pad 309 in the sacrificial layer 312;

[0094] refer to Figure 3G , forming a structural layer 315 on the sacrificial layer 312 and in the groove 313;

[0095] refer to Figure 3H The structure layer 315 is patterned to form a movable structure 318 , wherein the portion of the structure layer 315 located in the groove 313 forms a support portion 316 . Exemplarily, the portion of the structure layer 315 located on the sacrificial layer 312 forms a cantilever portion 317 .

[0096] refer to Figure 3I , removing the sacrificial layer 312 .

[0097] In the above process, since the stopper 308 has already been formed on the conductive layer 307, there is no need to etch the sacrificial layer 312 to form a groove for the stopper 308. Instead, the sacrificial layer 312 only needs to be etched to form the groove for the support portion 316 and the ground structure. Furthermore, the above process allows for control over the deposition thickness of the sacrificial layer 312 and the structural layer 315, thereby enabling precise control of the movable structure 318 of the MEMS device.

[0098] Exemplary materials for the sacrificial layer 312 include, but are not limited to, an inorganic insulating layer such as a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer, or an insulating layer such as an insulating layer comprising a material such as polyvinylphenol, polyimide, or siloxane. Furthermore, polyvinylphenol, polyimide, or siloxane can be effectively formed by droplet discharge, printing, or spin coating. Siloxane can be classified into silica glass, alkylsiloxane polymers, alkylsilsesquioxane polymers, silsesquioxane hydride polymers, and alkylsilsesquioxane hydride polymers, depending on their structure. Furthermore, the sacrificial layer 312 can be formed using a material including a polymer having Si-N bonds (polysilazane). Furthermore, these films can be stacked to form the sacrificial layer 312.

[0099] For example, the material of the structural layer 315 may be the same as or different from the material of the conductive layer 307. Specifically, the structural layer 315 may be at least one of the following materials: Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs, or other III / V compound semiconductors, including multilayer structures composed of these semiconductors.

[0100] Exemplary, reference Figure 3F In the process of etching the sacrificial layer 312, a grounding groove 314 communicating with the grounding hole 306 in the dielectric layer 304 may also be formed by etching. Figure 3G In the process of forming the structural layer 315, the formed structural layer 315 can fill the grounding hole 306 in the dielectric layer 304 and the grounding groove 314 in the sacrificial layer 312. Figure 3H and Figure 3I During the process of patterning the structural layer 315 , the structural layer 315 may also be patterned to obtain a grounding structure 319 electrically insulated from the movable structure 318 . The grounding structure 319 is electrically connected to the semiconductor substrate 301 through the grounding conductive layer 311 in the grounding hole 306 .

[0101] When removing the sacrificial layer 312 , a process such as, but not limited to, wet etching may be used to remove the sacrificial layer 312 .

[0102] At this point, the main steps in the method for preparing a MEMS device according to an embodiment of the present invention have been completed. It can be understood that the method for preparing a MEMS device in this embodiment not only includes the above steps, but may also include other necessary steps, which are all included in the scope of the method for preparing a MEMS device in this embodiment.

[0103] Example 3

[0104] Another embodiment of the present invention provides an electronic device including the aforementioned MEMS device.

[0105] The electronic device of this embodiment can be any electronic product or device, such as a mobile phone, tablet computer, laptop computer, netbook, game console, television, VCD, DVD, navigation system, camera, camcorder, voice recorder, MP3, MP4, PSP, or any other intermediate product that includes the MEMS device. The electronic device of this embodiment of the present invention, due to the use of the MEMS device, has improved performance.

[0106] The present invention has been described through the above-described embodiments. However, it should be understood that the above-described embodiments are for illustrative and illustrative purposes only and are not intended to limit the present invention to the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the above-described embodiments and that various variations and modifications may be made based on the teachings of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A MEMS device, characterized in that: include: semiconductor substrates; A dielectric layer disposed on a surface of the semiconductor substrate; A conductive layer disposed on a surface of the dielectric layer, the conductive layer having a stopper protruding toward a side away from the semiconductor substrate; A movable structure is arranged on the conductive layer, and the movable structure includes a supporting portion and a cantilever portion, wherein the cantilever portion is opposite to the stop block in a direction perpendicular to the surface of the semiconductor substrate, and the supporting portion is connected between the conductive layer and the cantilever portion.

2. The MEMS device according to claim 1, wherein: Also includes: A first boss is provided on the semiconductor substrate, wherein the dielectric layer covers the first boss and a second boss is conformally formed above the first boss, and the conductive layer covers the second boss and the stop block is conformally formed above the second boss.

3. The MEMS device according to claim 2, wherein: The conductive layer includes a fixed structure positioned opposite to and spaced from the cantilever portion, and a conductive pad electrically insulated from the fixed structure. The fixed structure is conformally formed with the stop block above the second boss, and the support portion is connected to the conductive pad.

4. The MEMS device according to any one of claims 1 to 3, wherein: There are multiple stop blocks, and the tops of the multiple stop blocks are at the same horizontal height.

5. The MEMS device according to claim 1, wherein: The MEMS device includes a MEMS inertial device, and the movable structure includes a movable comb structure of the MEMS inertial device.

6. A method for preparing a MEMS device, characterized in that: include: providing a semiconductor substrate; forming a dielectric layer on the surface of the semiconductor substrate; forming a conductive layer on the surface of the dielectric layer, wherein the conductive layer has a stopper protruding toward a side away from the semiconductor substrate; A movable structure is formed on the conductive layer, the movable structure including a support portion and a cantilever portion, wherein the cantilever portion is opposite to the stop block in a direction perpendicular to the surface of the semiconductor substrate, and the support portion is connected between the conductive layer and the cantilever portion.

7. The preparation method according to claim 6, wherein Before forming the dielectric layer on the surface of the semiconductor substrate, the preparation method further includes: forming a first boss on the semiconductor substrate; The dielectric layer covers the first boss and a second boss is formed conformally above the first boss; the conductive layer covers the second boss and a stop block is formed conformally above the second boss.

8. The preparation method according to claim 7, wherein The step of forming a first protrusion on the semiconductor substrate comprises: forming a dielectric material layer of a predetermined thickness on the semiconductor substrate; The dielectric material layer is etched to form the first protrusion.

9. The preparation method according to claim 7, wherein The conductive layer includes a conductive pad electrically insulated from the stop block; The forming of a movable structure on the conductive layer comprises: forming a sacrificial layer on the conductive layer; etching the sacrificial layer to form at least a groove exposing the conductive pad in the sacrificial layer; forming a structural layer on the sacrificial layer and in the groove; Patterning the structural layer to form the movable structure, wherein a portion of the structural layer located in the groove forms the supporting portion; The sacrificial layer is removed.

10. An electronic device, characterized in that: The electronic device includes the MEMS device according to any one of claims 1 to 5.

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