MEMS device and method of manufacturing the same

Abstract

The application provides a MEMS device and a manufacturing method thereof. The manufacturing method comprises the following steps: providing a first substrate with a formed sacrificial layer; forming a first insulating medium layer in the sacrificial layer; forming a semiconductor layer covering the sacrificial layer; forming a release hole and a movable mass in the semiconductor layer; releasing the sacrificial layer through the release hole to form a first cavity exposing the first insulating medium layer, the first insulating medium layer being located on a side of the movable mass close to the first substrate and serving as a first anti-adhesion structure; forming a second insulating medium layer in a second substrate; etching the second substrate outside the second insulating medium layer to form a second cavity, the second substrate reserved below the second insulating medium layer serving as a limiting structure, and the second insulating medium layer serving as a second anti-adhesion structure; and bonding the semiconductor layer with the second substrate, with the second anti-adhesion structure being aligned with the movable mass. The technical scheme of the application can avoid test failure and improve the reliability of the device.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a MEMS device and its manufacturing method. Background Technology

[0002] In conventional inertial devices, the Z-axis detection unit may come into contact with the limiting structure and anti-adhesion structure under extreme conditions during its up-and-down movement.

[0003] like Figure 1 As shown, the inertial device includes a first substrate 11 and a second substrate 12 bonded together. The first substrate 11 includes a semiconductor substrate 111, a conductive structure 112 electrically connected to the semiconductor substrate 111, a movable mass 113, and an anti-adhesion structure 114. The anti-adhesion structure 114 is located on the bottom surface of the movable mass 113. A limiting structure 121 is formed in the second substrate 12. The movable mass 113 and the anti-adhesion structure 114 are integral structures, as are the second substrate 12 and the limiting structure 121, and both are made of semiconductor materials. When the inertial device is powered on for testing, the movable mass 113 will move up and down. Under extreme conditions, this can lead to contact between the movable mass 113 and the limiting structure 121, and between the anti-adhesion structure 114 and the conductive structure 112, resulting in the discharge of test charge, which in turn leads to test failure and affects the reliability of the device.

[0004] Therefore, how to avoid test failures and improve device reliability is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a MEMS device and its manufacturing method, which can avoid test failures and improve the reliability of the device.

[0006] To achieve the above objectives, the present invention provides a method for manufacturing a MEMS device, comprising:

[0007] A first substrate is provided, on which a sacrificial layer is formed;

[0008] A first groove is formed in the sacrificial layer;

[0009] A first insulating dielectric layer is formed and filled into the first groove;

[0010] A semiconductor layer is formed covering the sacrificial layer, and the semiconductor layer covers the first insulating dielectric layer;

[0011] The semiconductor layer is etched and stopped at the sacrificial layer to form a release hole and a movable mass block in the semiconductor layer;

[0012] releasing part of the sacrificial layer through the release hole to form a first cavity, the first cavity exposing the first insulating medium layer and part of the first substrate, the first insulating medium layer being located on a side of the movable mass close to the first substrate, so that the first insulating medium layer serves as a first anti-sticking structure of the movable mass;

[0013] providing a second substrate;

[0014] forming a second recess in the second substrate;

[0015] forming a second insulating medium layer in the second recess;

[0016] etching the second substrate around the second insulating medium layer to form a second cavity, the second substrate remaining under the second insulating medium layer serving as a limiting structure, and the second insulating medium layer serving as a second anti-sticking structure of the limiting structure;

[0017] bonding a side of the semiconductor layer away from the first substrate to a side of the second substrate having the second cavity formed therein, the second anti-sticking structure being aligned with the movable mass.

[0018] Optionally, the first substrate comprises a semiconductor base and a third insulating medium layer covering the semiconductor base, and a conductive structure connected to the semiconductor base is formed in the third insulating medium layer; the first cavity exposes the third insulating medium layer and the conductive structure, and the exposed conductive structure is aligned with the first anti-sticking structure.

[0019] Optionally, a height difference between a top surface of the first insulating medium layer and a top surface of the sacrificial layer around the first recess is less than 1500 angstroms.

[0020] Optionally, a top surface of the second insulating medium layer is lower than a top surface of the second substrate around the second recess.

[0021] Optionally, after etching the second substrate around the second insulating medium layer, the method for manufacturing the MEMS device further comprises:

[0022] forming a gas absorption layer on a bottom wall of the second cavity.

[0023] Optionally, after forming the semiconductor layer to cover the sacrificial layer and before etching the semiconductor layer and stopping on the sacrificial layer, the method for manufacturing the MEMS device further comprises:

[0024] forming a first bonding ring on the semiconductor layer;

[0025] After forming the second insulating medium layer in the second recess and before etching the second substrate periphery of the second insulating medium layer, the method for manufacturing the MEMS device further comprises:

[0026] forming a second bonding ring on the second substrate;

[0027] The bonding of the one side of the semiconductor layer away from the first substrate to the one side of the second substrate forming the second cavity comprises: bonding the one side of the semiconductor layer away from the first substrate to the one side of the second substrate forming the second cavity through the first bonding ring and the second bonding ring.

[0028] Optionally, before the bonding of the one side of the semiconductor layer away from the first substrate to the one side of the second substrate forming the second cavity, the method for manufacturing the MEMS device further comprises:

[0029] forming a barrier wall body on the surface of the second substrate close to the second bonding ring.

[0030] Optionally, after the forming of the barrier wall body on the surface of the second substrate close to the second bonding ring, the method for manufacturing the MEMS device further comprises:

[0031] forming a barrier wall protection layer on the surface of the barrier wall body.

[0032] Optionally, the barrier wall body is formed simultaneously with the second insulating medium layer, and the barrier wall protection layer is formed simultaneously with the second bonding ring.

[0033] The application further provides a MEMS device, comprising:

[0034] a first substrate, a sacrificial layer and a semiconductor layer are formed on the first substrate, the semiconductor layer covers the sacrificial layer, a first cavity is formed in the sacrificial layer, a release hole and a movable mass are formed in the semiconductor layer, the release hole is communicated with the first cavity, a first insulating medium layer is formed on the one side of the movable mass close to the first substrate, the first cavity exposes the first insulating medium layer and part of the first substrate, and the first insulating medium layer serves as a first anti-adhesion structure of the movable mass;

[0035] A second substrate is bonded on the semiconductor layer, one side of the second substrate close to the semiconductor layer is formed with a second cavity, the second cavity is communicated with the release hole, a limiting structure is formed in the second cavity, the limiting structure is an integral structure with the second substrate and extends to the semiconductor layer, one end of the limiting structure close to the semiconductor layer is formed with a second insulating medium layer, the second insulating medium layer is used as a second anti-adhesion structure of the limiting structure, and the second anti-adhesion structure is aligned with the movable mass.

[0036] Optionally, the first substrate comprises a semiconductor base and a third insulating medium layer covering the semiconductor base, and a conductive structure connected with the semiconductor base is formed in the third insulating medium layer; the first cavity exposes the third insulating medium layer and the conductive structure, and the exposed conductive structure is aligned with the first anti-adhesion structure.

[0037] Optionally, a height difference between one side of the first insulating medium layer away from the first substrate and one side of the sacrificial layer away from the first substrate is less than 1500 angstroms.

[0038] Optionally, one side of the second insulating medium layer close to the semiconductor layer is higher than one side of the second substrate close to the semiconductor layer at the periphery of the second cavity.

[0039] Optionally, the MEMS device further comprises:

[0040] A gas absorption layer is formed on a bottom wall of the second cavity.

[0041] Optionally, the MEMS device further comprises:

[0042] A first bonding ring is formed on one side of the semiconductor layer away from the first substrate.

[0043] A second bonding ring is formed on one side of the second substrate close to the semiconductor layer, and one side of the semiconductor layer away from the first substrate and one side of the second substrate close to the semiconductor layer are bonded through the first bonding ring and the second bonding ring.

[0044] Optionally, the MEMS device further comprises:

[0045] A barrier wall body is formed on a surface of the second substrate close to the second bonding ring.

[0046] Optionally, the MEMS device further comprises:

[0047] A barrier wall protection layer is formed on a surface of the barrier wall body.

[0048] Optionally, the barrier wall body is made of the same material as the second insulating medium layer, and the barrier wall protection layer is made of the same material as the second bonding ring.

[0049] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0050] 1. The manufacturing method of the MEMS device, by providing a first substrate, the first substrate is formed with a sacrificial layer; a first groove is formed in the sacrificial layer; a first insulating medium layer is formed to fill the first groove; a semiconductor layer is formed to cover the sacrificial layer, and the semiconductor layer covers the first insulating medium layer; the semiconductor layer is etched and stopped on the sacrificial layer to form a release hole and a movable mass in the semiconductor layer; part of the sacrificial layer is released through the release hole to form a first cavity, the first cavity exposes the first insulating medium layer and part of the first substrate, the first insulating medium layer is located on the side of the movable mass close to the first substrate, so that the first insulating medium layer serves as the first anti-adhesion structure of the movable mass; a second substrate is provided; a second groove is formed in the second substrate; a second insulating medium layer is formed in the second groove; the second substrate around the second insulating medium layer is etched to form a second cavity, the second substrate reserved below the second insulating medium layer serves as a limiting structure, and the second insulating medium layer serves as a second anti-adhesion structure of the limiting structure; the side of the semiconductor layer away from the first substrate is bonded to the side of the second substrate with the second cavity, and the second anti-adhesion structure is aligned with the movable mass, so that the movable mass and the structures above and below it are insulated while avoiding adhesion, thereby avoiding the test charge from being led out, avoiding test failure, and improving the reliability of the device.

[0051] 2、The MEMS device of the present application, comprising: a first substrate, a sacrificial layer and a semiconductor layer being formed on the first substrate, the semiconductor layer covering the sacrificial layer, a first cavity being formed in the sacrificial layer, a release hole and a movable mass being formed in the semiconductor layer, the release hole being communicated with the first cavity, a first insulating medium layer being formed on the side of the movable mass close to the first substrate, the first cavity exposing the first insulating medium layer and part of the first substrate, the first insulating medium layer serving as a first anti-adhesion structure of the movable mass; a second substrate being bonded on the semiconductor layer, a second cavity being formed on the side of the second substrate close to the semiconductor layer, the second cavity being communicated with the release hole, a limiting structure being formed in the second cavity, the limiting structure being an integral structure with the second substrate and extending towards the semiconductor layer, a second insulating medium layer being formed on the end of the limiting structure close to the semiconductor layer, the second insulating medium layer serving as a second anti-adhesion structure of the limiting structure, the second anti-adhesion structure being aligned with the movable mass, so that the movable mass and the structures above and below the movable mass are insulated while avoiding adhesion between the movable mass and the structures above and below the movable mass, thereby avoiding test charge from being led out, avoiding test failure, and improving the reliability of the device. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 is a sectional view of a MEMS device;

[0053] Figure 2 is a flow chart of the manufacturing method of the MEMS device of the embodiment of the present application;

[0054] Figures 3a to 3m is Figure 2 is a sectional view of the device in the manufacturing method of the MEMS device.

[0055] wherein the accompanying Figures 1 to 3m The reference signs in the accompanying

[0056] 11 - first substrate; 111 - semiconductor substrate; 112 - conductive structure; 113 - movable mass; 114 - anti-sticking structure; 12 - second substrate; 121 - limiting structure; 21 - first substrate; 211 - semiconductor substrate; 212 - third insulating medium layer; 213 - conductive structure; 214 - fourth insulating medium layer; 22 - sacrificial layer; 221 - first recess; 222 - first insulating medium layer; 223 - first cavity; 23 - semiconductor layer; 231 - release hole; 232 - movable mass; 233 - fixed mass; 234 - movable comb-tooth structure; 24 - first bonding ring; 31 - second substrate; 311 - second recess; 312 - second insulating medium layer; 313 - second cavity; 314 - limiting structure; 32 - barrier structure; 321 - barrier body; 322 - barrier protection layer; 33 - second bonding ring; 34 - gas absorption layer. DETAILED DESCRIPTION

[0057] To make the objects, advantages and features of the present application more clear, the following further describes the MEMS device and the manufacturing method thereof according to the present application. It should be noted that all the drawings are in a very simplified form and all use non-precise proportions, only for the purpose of conveniently and clearly assisting the description of the embodiments of the present application.

[0058] An embodiment of the present application provides a manufacturing method of a MEMS device, referring to Figure 2 , Figure 2 is a flow chart of the manufacturing method of the MEMS device according to an embodiment of the present application, and the manufacturing method of the MEMS device comprises:

[0059] Step S1, providing a first substrate, wherein a sacrificial layer is formed on the first substrate;

[0060] Step S2, forming a first recess in the sacrificial layer;

[0061] Step S3, forming a first insulating medium layer filled in the first recess;

[0062] Step S4, forming a semiconductor layer covering the sacrificial layer, and the semiconductor layer covers the first insulating medium layer;

[0063] Step S5, etching the semiconductor layer and stopping on the sacrificial layer, so as to form a release hole and a movable mass in the semiconductor layer;

[0064] Step S6, releasing part of the sacrificial layer through the release hole, so as to form a first cavity, wherein the first cavity exposes the first insulating medium layer and part of the first substrate, and the first insulating medium layer is located on a side of the movable mass close to the first substrate, so that the first insulating medium layer serves as a first anti-sticking structure of the movable mass;

[0065] Step S7, providing a second substrate;

[0066] Step S8, forming a second recess in the second substrate;

[0067] Step S9, forming a second insulating medium layer in the second recess;

[0068] Step S10, etching the second substrate around the periphery of the second insulating medium layer to form a second cavity, the second substrate remaining under the second insulating medium layer as a limiting structure, and the second insulating medium layer as a second anti-adhesion structure of the limiting structure;

[0069] Step S11, bonding the semiconductor layer away from the side of the first substrate to the side of the second substrate with the second cavity formed, and the second anti-adhesion structure aligned with the movable mass.

[0070] Reference will now be made to Figures 3a to 3m A more detailed description of the manufacturing method of the MEMS device provided by the embodiment will be given below, Figures 3a to 3m is Figure 2 a device schematic diagram in the manufacturing method of the MEMS device shown, Figures 3a to 3m is also a longitudinal cross-sectional schematic diagram of the MEMS device.

[0071] According to step S1, reference is made to Figure 3a , a first substrate 21 is provided, and a sacrificial layer 22 is formed on the first substrate 21.

[0072] The first substrate 21 can include a semiconductor substrate 211 and a third insulating medium layer 212 covering the semiconductor substrate 211, and a conductive structure 213 connected to the semiconductor substrate 211 is formed in the third insulating medium layer 212, the third insulating medium layer 212 exposes the conductive structure 213, and the sacrificial layer 22 covers the third insulating medium layer 212 and the conductive structure 213.

[0073] The material of the semiconductor substrate 211 can include Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs or other III / V compound semiconductors, and can also include a multilayer structure composed of these semiconductors, etc.; or the semiconductor substrate 211 can be silicon-on-insulator (SOI), stacked silicon-on-insulator (SSOI), stacked silicon germanium-on-insulator (S-SiGeOI), silicon germanium-on-insulator (SiGeOI), and germanium-on-insulator (GeOI), etc. Those skilled in the art can select as needed.

[0074] The material of the third insulating dielectric layer 212 can be at least one of insulating materials such as silicon oxide, silicon oxynitride, and silicon nitride, and the third insulating dielectric layer 212 can be a structure of at least two stacked layers.

[0075] The conductive structure 213 can be made of polycrystalline silicon or metal.

[0076] Device structures may also be formed in the semiconductor substrate 211 and the third insulating dielectric layer 212, and the device structures may include transistors, etc.

[0077] The material of the sacrificial layer 22 includes, but is not limited to, silicon oxide.

[0078] The side of the first substrate 21 away from the sacrificial layer 22 may be covered with a fourth insulating dielectric layer 214, so that the side of the first substrate 21 away from the sacrificial layer 22 is insulated from other structures.

[0079] Follow step S2, see Figure 3b The sacrificial layer 22 is etched to form a first groove 221 in the sacrificial layer 22.

[0080] The number of the first groove 221 is preferably at least two.

[0081] The first groove 221 does not expose the first substrate 21.

[0082] Follow step S3, see [link / reference] Figure 3c A first insulating dielectric layer 222 is formed and filled in the first groove 221.

[0083] The steps may include: first, depositing insulating material on the sacrificial layer 22, and filling the first groove 221 with insulating material; then, removing the insulating material on the sacrificial layer 22 surrounding the first groove 221 by an etching process or a chemical mechanical polishing process, and retaining the insulating material in the first groove 221 as the first insulating dielectric layer 222.

[0084] The top surface of the first insulating dielectric layer 222 may be higher or lower than the top surface of the sacrificial layer 22 surrounding the first groove 221, or the top surface of the first insulating dielectric layer 222 may be flush with the top surface of the sacrificial layer 22 surrounding the first groove 221; preferably, the height difference between the top surface of the first insulating dielectric layer 222 and the top surface of the sacrificial layer 22 surrounding the first groove 221 is less than 1500 angstroms.

[0085] The etching rate difference between the sacrificial layer 22 and the first insulating medium layer 222 is large, for example, the etching selectivity ratio between the sacrificial layer 22 and the first insulating medium layer 222 is greater than 10, so that subsequent etching of the sacrificial layer 22 can avoid etching of the first insulating medium layer 222 or only a small amount of etching of the first insulating medium layer 222.

[0086] The material of the first insulating medium layer 222 can be silicon nitride or silicon oxynitride, etc.

[0087] According to step S4, referring to Figure 3d , a semiconductor layer 23 is formed to cover the sacrificial layer 22, and the semiconductor layer 23 covers the first insulating medium layer 222.

[0088] The semiconductor layer 23 can be formed by epitaxy process.

[0089] The material of the semiconductor layer 23 can include Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs or other III / V compound semiconductors, and can also include a multilayer structure formed by these semiconductors, etc.

[0090] And, referring to Figure 3e , after the semiconductor layer 23 is formed to cover the sacrificial layer 22 and before subsequent etching of the semiconductor layer 23 and stopping on the sacrificial layer 22, the manufacturing method of the MEMS device further includes: forming a first bonding ring 24 on the semiconductor layer 23.

[0091] The step of forming the first bonding ring 24 on the semiconductor layer 23 can include: first, forming a metal material on the semiconductor layer 23 by sputtering or evaporation process; then, forming a patterned mask layer (not shown) on the metal material; then, etching the metal material with the patterned mask layer as a mask to form the first bonding ring 24; then, removing the patterned mask layer. Wherein, the first bonding ring 24 can also be formed on the semiconductor layer 23 at the same time as forming a pad or other structure.

[0092] The material of the first bonding ring 24 can include germanium, aluminum, copper, nickel or gold and other metal materials.

[0093] According to step S5, referring to Figure 3fetching the semiconductor layer 23 and stopping at the sacrificial layer 22 to form a movable mass 232, a fixed mass 233 and a movable comb structure 234 in the semiconductor layer 23, and the movable mass 232, the fixed mass 233 and the movable comb structure 234 form release holes 231 therebetween, and the movable comb structure 234 also forms release holes 231 therein, and the release holes 231 expose the sacrificial layer 22.

[0094] The first insulating medium layer 222 is aligned with the movable mass 232, i.e. the first insulating medium layer 222 is formed between the movable mass 232 and the sacrificial layer 22.

[0095] According to step S6, referring to Figure 3g releasing part of the sacrificial layer 22 through the release holes 231 to form a first cavity 223 in the sacrificial layer 22, the first cavity 223 exposes the first insulating medium layer 222 and part of the first substrate 21, and the first insulating medium layer 222 is located on the side of the movable mass 232 close to the first substrate 21, so that the first insulating medium layer 222 serves as a first anti-sticking structure of the movable mass 232.

[0096] The gaseous hydrofluoric acid (Vapor HF, VHF) etching process can be used to release part of the sacrificial layer 22, i.e. gaseous hydrofluoric acid is introduced into the release holes 231 to etch and remove part of the sacrificial layer 22 through the release holes 231.

[0097] Moreover, the sacrificial layer 22 between the movable mass 232 and the movable comb structure 234 and the first substrate 21 is completely removed, so that the movable mass 232 and the movable comb structure 234 can move up and down; and part of the sacrificial layer 22 remains between the fixed mass 233 and the first substrate 21, so that the fixed mass 233 can be fixed.

[0098] Due to the high etching selectivity of the etching process to the first insulating medium layer 222 at this moment, after the etching removal of the sacrificial layer 22 around the first insulating medium layer 222, the first insulating medium layer 222 can be reserved on the side of the movable mass 232 close to the first substrate 21, and the first insulating medium layer 222 is exposed by the first cavity 223, so that the first insulating medium layer 222 can serve as the first anti-sticking structure of the movable mass 232 to avoid the sticking between the movable mass 232 and the first substrate 21 under extreme conditions; and due to the insulating material of the first anti-sticking structure, the movable mass 232 and the first substrate 21 can also be insulated under extreme conditions, so as to avoid the test charge from being led out, thereby avoiding test failure and improving the reliability of the device.

[0099] The first cavity 223 can expose the third insulating medium layer 212 and the conductive structure 213, and the exposed conductive structure 213 is aligned with the first anti-sticking structure, so that the movable mass 232 and the conductive structure 213 are insulated by the first anti-sticking structure under extreme conditions.

[0100] According to step S7, referring to Figure 3h , a second substrate 31 is provided.

[0101] The second substrate 31 can be only a semiconductor substrate or a wafer containing a semiconductor substrate, and device structures such as transistors can be formed in the second substrate 31 as needed.

[0102] According to step S8, referring to Figure 3h , the second substrate 31 is etched to form a second groove 311 in the second substrate 31.

[0103] The number of the second groove 311 is at least one.

[0104] According to step S9, referring to Figure 3i , a second insulating medium layer 312 is formed in the second groove 311.

[0105] The top surface of the second insulating medium layer 312 is lower than the top surface of the second substrate 31 around the second groove 311, so that after the bonding of the first substrate 21 and the second substrate 31, there is enough distance between the second insulating medium layer 312 and the movable mass 232, that is, enough space for the movable mass 232 to move up and down.

[0106] Preferably, the top surface of the second insulating medium layer 312 is 2-3 μm lower than the top surface of the second substrate 31 outside the second groove 311.

[0107] The step of forming the second insulating medium layer 312 in the second groove 311 can include: first, depositing insulating material on the second substrate 31, and the insulating material fills the second groove 311; then, using an etching process to remove the insulating material on the second substrate 31 outside the second groove 311 and part of the thickness of the insulating material in the second groove 311, only retaining part of the thickness of the insulating material in the second groove 311 as the second insulating medium layer 312. At this time, part of the insulating material on the sidewall of the second groove 311 can also be removed.

[0108] The material of the second insulating medium layer 312 can be at least one of silicon oxide, silicon nitride, and silicon oxynitride.

[0109] In addition, referring to FIG. 3.j, after forming the second insulating medium layer 312 in the second groove 311 and before etching the second substrate 31 outside the second insulating medium layer 312, the method for manufacturing the MEMS device further includes: forming a second bonding ring 33 on the second substrate 31.

[0110] The step of forming the second bonding ring 33 on the second substrate 31 can include: first, forming a metal material on the second substrate 31 using a sputtering or evaporation process; then, forming a patterned mask layer (not shown) on the metal material; then, etching the metal material with the patterned mask layer as a mask to form the second bonding ring 33; and then, removing the patterned mask layer. At this time, a pad or other structure can also be formed on the second substrate 31 at the same time as the second bonding ring 33.

[0111] The material of the second bonding ring 33 can include a metal material such as germanium, aluminum, copper, nickel, or gold.

[0112] According to step S10, referring to FIG. 3.i, the second insulating medium layer 312 is formed in the second groove 311. Figure 3k The second substrate 31 outside the second insulating medium layer 312 is etched to form a second cavity 313, and the second substrate 31 remaining below the second insulating medium layer 312 serves as a limiting structure 314, and the second insulating medium layer 312 serves as a second anti-adhesion structure of the limiting structure 314.

[0113] At this time, part of the second substrate 31 below the second insulating medium layer 312 can also be etched and removed, so that part of the bottom surface of the second insulating medium layer 312 is exposed.

[0114] After the first substrate 21 is bonded to the second substrate 31, the second cavity 313 is aligned with the movable mass 232, the fixed mass 233 and the movable comb-tooth structure 234, and the second cavity 313 is used to provide a space for the movable mass 232 and the movable comb-tooth structure 234 to move up and down.

[0115] In addition, after the first substrate 21 is bonded to the second substrate 31, the limiting structure 314 is aligned with the movable mass 232 to limit the range of the movable mass 232 to move up and down, so as to avoid the problem of the movable mass 232 being broken due to excessive vibration.

[0116] In addition, referring to FIG. 31, after the second substrate 31 is etched around the second insulating medium layer 312, the method for manufacturing the MEMS device further comprises: forming a gas absorption layer 34 on the bottom wall of the second cavity 313, and the gas absorption layer 34 is used to absorb gas to improve the vacuum degree of the MEMS device.

[0117] In this embodiment, the thick glue process is used to form a photoresist layer which exposes the second cavity 313, and the gas absorption layer 34 is deposited on the exposed bottom of the second cavity 313.

[0118] The material of the gas absorption layer 34 can be a metal material.

[0119] According to step S11, referring to Figure 3m The side of the semiconductor layer 23 away from the first substrate 21 is bonded to the side of the second substrate 31 which has the second cavity 313, and after the bonding, the second anti-adhesion structure is aligned with the movable mass 232.

[0120] Since the second anti-adhesion structure is aligned with the movable mass 232, the second anti-adhesion structure can avoid the adhesion between the movable mass 232 and the limiting structure 314 under extreme conditions when the movable mass 232 moves up and down. In addition, since the material of the second anti-adhesion structure is an insulating material, the movable mass 232 and the limiting structure 314 can also be insulated under extreme conditions, so as to avoid the test charge being led out, thereby avoiding the test failure and improving the reliability of the device.

[0121] The bonding of the side of the semiconductor layer 23 away from the first substrate 21 to the side of the second substrate 31 having the second cavity 313 formed thereon comprises bonding the side of the semiconductor layer 23 away from the first substrate 21 to the side of the second substrate 31 having the second cavity 313 formed thereon through the first bonding ring 24 and the second bonding ring 33.

[0122] The first bonding ring 24 and the second bonding ring 33 are both annular structures, and the first bonding ring 24 and the second bonding ring 33 can have the same size or a size close to the same. The first bonding ring 24 and the second bonding ring 33 can be eutectic bonded.

[0123] In the bonding, the side of the semiconductor layer 23 away from the first substrate 21 is opposite to the side of the second substrate 31 having the second cavity 313 formed thereon, the first bonding ring 24 is aligned with the second bonding ring 33, and a certain pressure is applied so that the first bonding ring 24 and the second bonding ring 33 are in contact and a bonding reaction occurs under a set condition to form a metal block, and the distance between the first substrate 21 and the second substrate 31 is further reduced. When the first bonding ring 24 and the second bonding ring 33 are made of different materials (for example, the first bonding ring 24 is made of aluminum and the second bonding ring 33 is made of germanium), the metal block is an alloy.

[0124] Preferably, before the bonding of the side of the semiconductor layer 23 away from the first substrate 21 to the side of the second substrate 31 having the second cavity 313 formed thereon, the method for manufacturing the MEMS device further comprises forming a barrier wall body 321 on the surface of the second substrate 31 close to the second bonding ring 33.

[0125] The barrier wall body 321 is made of an insulating material.

[0126] Preferably, after the formation of the barrier wall body 321 on the surface of the second substrate 31 close to the second bonding ring 33 and before the bonding of the side of the semiconductor layer 23 away from the first substrate 21 to the side of the second substrate 31 having the second cavity 313 formed thereon, the method for manufacturing the MEMS device further comprises forming a barrier wall protection layer 322 on the surface of the barrier wall body 321.

[0127] The barrier wall protection layer 322 is made of a metal material.

[0128] Further preferably, as shown in FIG. 1C, the barrier wall body 321 is formed simultaneously with the second insulating medium layer 312; as shown in FIG. 1D, the barrier wall body 321 is formed simultaneously with the second insulating medium layer 312 and the second bonding ring 33. Figure 3i Figure 3j ​As shown, the barrier wall protection layer 322 is formed simultaneously with the second bonding ring 33, so that the process steps are simplified and the cost is reduced.

[0129] Due to the bonding, a melting reaction occurs between the first bonding ring 24 and the second bonding ring 33 under high temperature and high bonding pressure, and the generated molten fluid flows around. The barrier wall body 321 can block the molten fluid from flowing to the middle region and / or the edge region of the semiconductor layer 23 and the second substrate 31.

[0130] The barrier wall protection layer 322 is used to avoid the barrier wall body 321 from being damaged during the etching process of forming the second cavity 313, so as to avoid that the barrier wall body 321 cannot limit the flow of the molten fluid according to the designed position.

[0131] The barrier wall body 321 and the barrier wall protection layer 322 can jointly constitute a barrier wall structure 32, and the barrier wall structure 32 has a gap between the second bonding ring 33 and the first bonding ring 24, so as to avoid that the barrier wall protection layer 322 made of metal material flows around with the molten alloy generated by the bonding reaction.

[0132] In addition, the inner side or the outer side of the second bonding ring 33 can be formed with the barrier wall structure 32, or both the inner side and the outer side of the second bonding ring 33 can be formed with the barrier wall structure 32; and the barrier wall structure 32 can be a ring structure.

[0133] In addition, the barrier wall structure 32 can also serve as a support structure for controlling the bonding reaction, and the height of the barrier wall structure 32 can be set according to the required bonding degree. In the initial stage of bonding, there is still a gap between the upper surface of the barrier wall structure 32 and the semiconductor layer 23, and the gap decreases with the progress of the bonding reaction. When the side of the barrier wall structure 32 away from the second substrate 31 contacts the surface of the semiconductor layer 23, it indicates that the bonding reaction has reached the degree required for bonding, and then the bonding process stops.

[0134] It should be noted that the steps S1-S6 and the steps S7-S10 can be performed simultaneously.

[0135] From the above, the manufacturing method of the MEMS device of the present application, when the MEMS device is powered on for testing, since the one side of the movable mass 232 close to the first substrate 21 is formed with the first insulating medium layer 222, and the first insulating medium layer 222 serves as the first anti-adhesion structure of the movable mass 232, so that when the movable mass 232 moves up and down, the first anti-adhesion structure can avoid the adhesion between the movable mass 232 and the first substrate 21 under extreme conditions, and can keep the insulation between the movable mass 232 and the first substrate 21 under extreme conditions through the first anti-adhesion structure; and since the limiting structure 314 integrated with the second substrate 31 is formed with the second insulating medium layer 312 close to one end of the semiconductor layer 23, and the second insulating medium layer 312 serves as the second anti-adhesion structure of the limiting structure 314, the second anti-adhesion structure is aligned with the movable mass 232, so that when the movable mass 232 moves up and down, the second anti-adhesion structure can avoid the adhesion between the movable mass 232 and the limiting structure 314 under extreme conditions, and can keep the insulation between the movable mass 232 and the limiting structure 314 under extreme conditions through the second anti-adhesion structure. Therefore, the manufacturing method of the MEMS device of the present application can not only avoid the adhesion between the movable mass and the structure above and below it, but also can keep the insulation between the movable mass and the structure above and below it, thereby avoiding the test charge from being led out, avoiding the test failure, and improving the reliability of the device.

[0136] An embodiment of the present application provides a MEMS device, which comprises: a first substrate, a sacrificial layer and a semiconductor layer are formed on the first substrate, the semiconductor layer covers the sacrificial layer, a first cavity is formed in the sacrificial layer, a release hole and a movable mass are formed in the semiconductor layer, the release hole is communicated with the first cavity, a first insulating medium layer is formed on the one side of the movable mass close to the first substrate, the first cavity exposes the first insulating medium layer and part of the first substrate, and the first insulating medium layer serves as a first anti-adhesion structure of the movable mass; and a second substrate, which is bonded on the semiconductor layer, the second substrate is formed with a second cavity close to the semiconductor layer, the second cavity is communicated with the release hole, and a limiting structure is formed in the second cavity, the limiting structure is an integral structure with the second substrate and extends to the semiconductor layer, a second insulating medium layer is formed on one end of the limiting structure close to the semiconductor layer, and the second insulating medium layer serves as a second anti-adhesion structure of the limiting structure, and the second anti-adhesion structure is aligned with the movable mass.

[0137] Hereinafter, the MEMS device of the present embodiment will be described in detail. Figure 3m The MEMS device of the present embodiment will be described in detail.

[0138] The first substrate 21 is provided with a sacrificial layer 22 and a semiconductor layer 23, the semiconductor layer 23 covers the sacrificial layer 22, the sacrificial layer 22 is provided with a first cavity 223, the semiconductor layer 23 is provided with a release hole 231 and a movable mass 232, the release hole 231 is communicated with the first cavity 223, the movable mass 232 is provided with a first insulating medium layer 222 on the side close to the first substrate 21, the first cavity 223 exposes the first insulating medium layer 222 and part of the first substrate 21, and the first insulating medium layer 222 serves as a first anti-adhesion structure of the movable mass 232.

[0139] The first substrate 21 can include a semiconductor base 211 and a third insulating medium layer 212 covering the semiconductor base 211, the third insulating medium layer 212 is provided with a conductive structure 213 connected with the semiconductor base 211, the third insulating medium layer 212 exposes the conductive structure 213, and the sacrificial layer 22 covers part of the third insulating medium layer 212 and part of the conductive structure 213.

[0140] The semiconductor base 211 and the third insulating medium layer 212 can also be provided with a device structure, which can include a transistor and the like.

[0141] The side of the first substrate 21 away from the sacrificial layer 22 can be covered with a fourth insulating medium layer 214, so that the side of the first substrate 21 away from the sacrificial layer 22 is insulated from other structures.

[0142] Preferably, the side of the movable mass 232 close to the first substrate 21 is provided with at least two first insulating medium layers 222 arranged at intervals, so as to further avoid the movable mass 232 from adhering to the first substrate 21 when moving up and down.

[0143] The side of the first insulating medium layer 222 away from the first substrate 21 can be higher or lower than the side of the sacrificial layer 22 away from the first substrate 21, or the side of the first insulating medium layer 222 away from the first substrate 21 is flush with the side of the sacrificial layer 22 away from the first substrate 21; preferably, the height difference between the side of the first insulating medium layer 222 away from the first substrate 21 and the side of the sacrificial layer 22 away from the first substrate 21 is less than 1500 angstroms.

[0144] The semiconductor layer 23 further forms a fixed mass 233 and a movable comb structure 234, and the movable mass 232, the fixed mass 233 and the movable comb structure 234 form the release hole 231 therebetween, and the movable comb structure 234 also forms the release hole 231, and the first cavity 223 provides a space for the movable mass 232 and the movable comb structure 234 to move up and down.

[0145] Further, the movable mass 232 and the movable comb structure 234 are completely removed from the sacrificial layer 22 between the movable mass 232 and the movable comb structure 234 and the first substrate 21, so that the movable mass 232 and the movable comb structure 234 can move up and down; and the fixed mass 233 retains part of the sacrificial layer 22 between the fixed mass 233 and the first substrate 21, so that the fixed mass 233 can be fixed.

[0146] Since the movable mass 232 forms the first insulating medium layer 222 on the side close to the first substrate 21, and the first cavity 223 exposes the first insulating medium layer 222, when the movable mass 232 moves up and down, the first insulating medium layer 222 can act as a first anti-sticking structure of the movable mass 232, avoiding sticking between the movable mass 232 and the first substrate 21 under extreme conditions; and since the material of the first anti-sticking structure is an insulating material, the movable mass 232 and the first substrate 21 can also be insulated under extreme conditions, avoiding the test charge being led out, thereby avoiding test failure and improving the reliability of the device.

[0147] The first cavity 223 can expose part of the third insulating medium layer 212 and part of the conductive structure 213, and the exposed conductive structure 213 is aligned with the first anti-sticking structure, so that the movable mass 232 and the conductive structure 213 are insulated by the first anti-sticking structure under extreme conditions.

[0148] The material of the semiconductor substrate 211 can include Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs or other III / V compound semiconductors, and can also include a multilayer structure composed of these semiconductors, etc.; or the semiconductor substrate 211 can be silicon-on-insulator (SOI), stacked silicon-on-insulator (SSOI), stacked germanium-silicon-on-insulator (S-SiGeOI), germanium-silicon-on-insulator (SiGeOI) and germanium-on-insulator (GeOI), etc. Those skilled in the art can select as needed.

[0149] The third insulating medium layer 212 can be made of at least one of silicon oxide, silicon oxynitride, and silicon nitride, and can be a structure of at least two layers stacked.

[0150] The conductive structure 213 can be made of polysilicon or metal.

[0151] The sacrificial layer 22 can be made of silicon oxide, but is not limited thereto.

[0152] The first insulating medium layer 222 can be made of silicon nitride or silicon oxynitride.

[0153] The semiconductor layer 23 can be made of Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs, or other III / V compound semiconductors, and can also be made of a multilayer structure of these semiconductors.

[0154] The second substrate 31 is bonded to the semiconductor layer 23, and a second cavity 313 is formed on a side of the second substrate 31 close to the semiconductor layer 23. The second cavity 313 is in communication with the release hole 231, and a limiting structure 314 is formed in the second cavity 313. The limiting structure 314 is an integral structure of the second substrate 31 and extends toward the semiconductor layer 23. A second insulating medium layer 312 is formed on an end of the limiting structure 314 close to the semiconductor layer 23. The second insulating medium layer 312 serves as a second anti-adhesion structure of the limiting structure 314, and is aligned with the movable mass 232.

[0155] The second substrate 31 can be a semiconductor substrate or a wafer containing a semiconductor substrate, and a device structure such as a transistor can be formed in the second substrate 31 as needed.

[0156] The second insulating medium layer 312 can be higher than a side of the second substrate 31 close to the semiconductor layer 23 at the periphery of the second cavity 313, so that a sufficient distance is provided between the second insulating medium layer 312 and the movable mass 232, and a sufficient space for the movable mass 232 to move up and down is provided.

[0157] Preferably, the second insulating medium layer 312 can be 2 μm to 3 μm higher than a side of the second substrate 31 close to the semiconductor layer 23 at the periphery of the second cavity 313.

[0158] The second insulating medium layer 312 can be made of at least one of silicon oxide, silicon nitride, and silicon oxynitride.

[0159] The second cavity 313 is aligned with the movable mass 232, the fixed mass 233 and the movable comb-tooth structure 234, and is used to provide a space for the movable mass 232 and the movable comb-tooth structure 234 to move up and down.

[0160] The limiting structure 314 is aligned with the movable mass 232, and is used to limit the range of the movable mass 232 to move up and down, so as to avoid the problem of the movable mass 232 being broken due to excessive vibration.

[0161] Since the second anti-adhesion structure is aligned with the movable mass 232, the second anti-adhesion structure can avoid the movable mass 232 and the limiting structure 314 from being adhered under extreme conditions when the movable mass 232 moves up and down. In addition, since the material of the second anti-adhesion structure is an insulating material, the movable mass 232 and the limiting structure 314 can also be insulated under extreme conditions, so as to avoid the test charge being led out, thereby avoiding causing test failure and improving the reliability of the device.

[0162] The MEMS device can further include a gas absorption layer 34 formed on the bottom wall of the second cavity 313, and the gas absorption layer 34 is used to absorb gas, so as to improve the vacuum degree of the MEMS device. The material of the gas absorption layer 34 can be a metal material.

[0163] The MEMS device further includes:

[0164] A first bonding ring 24 is formed on the side of the semiconductor layer 23 away from the first substrate 21.

[0165] A second bonding ring 33 is formed on the side of the second substrate 31 close to the semiconductor layer 23, and the side of the semiconductor layer 23 away from the first substrate 21 and the side of the second substrate 31 close to the semiconductor layer 23 are bonded through the first bonding ring 24 and the second bonding ring 33.

[0166] The material of the first bonding ring 24 and the second bonding ring 33 can include a metal material such as germanium, aluminum, copper, nickel or gold.

[0167] The first bonding ring 24 and the second bonding ring 33 are both ring structures, and the size of the first bonding ring 24 and the second bonding ring 33 can be the same or close to the same, and the first bonding ring 24 and the second bonding ring 33 can be eutectic bonding.

[0168] In the bonding process, the semiconductor layer 23 is opposite to the surface of the second substrate 31 where the second cavity 313 is formed, and the first bonding ring 24 is aligned with the second bonding ring 33, and a pressure is applied so that the first bonding ring 24 and the second bonding ring 33 are in contact and form a metal block under a certain condition, and the distance between the first substrate 21 and the second substrate 31 is closer. When the material of the first bonding ring 24 and the second bonding ring 33 is different (for example, the material of the first bonding ring 24 is aluminum, and the material of the second bonding ring 33 is germanium), the metal block is an alloy.

[0169] Preferably, the MEMS device further comprises a barrier body 321 formed on the surface of the second substrate 31 close to the second bonding ring 33.

[0170] The material of the barrier body 321 is an insulating material.

[0171] Preferably, the MEMS device further comprises a barrier protection layer 322 formed on the surface of the barrier body 321.

[0172] The material of the barrier protection layer 322 is a metal material.

[0173] Further preferably, the material of the barrier body 321 is the same as that of the second insulating medium layer 312, and the material of the barrier protection layer 322 is the same as that of the second bonding ring 33, that is, the barrier body 321 and the second insulating medium layer 312 are formed at the same time, and the barrier protection layer 322 and the second bonding ring 33 are formed at the same time, so that the process steps are simplified and the cost is reduced.

[0174] Because of the melting reaction between the first bonding ring 24 and the second bonding ring 33 under high temperature and high bonding pressure during the bonding process, the molten fluid generated will flow around, and the barrier body 321 can block the molten fluid from flowing to the middle and / or edge regions of the semiconductor layer 23 and the second substrate 31.

[0175] The barrier protection layer 322 is used to avoid damage to the barrier body 321 during the etching process of forming the second cavity 313, thereby avoiding that the barrier body 321 cannot limit the flow of molten fluid according to the designed position.

[0176] The barrier body 321 and the barrier protection layer 322 can jointly constitute a barrier structure 32, and there is a gap between the barrier structure 32 and the second bonding ring 33 and the first bonding ring 24, so as to avoid that the barrier protection layer 322 made of metal material and the molten alloy generated by the bonding reaction flow around.

[0177] And, the inner side or the outer side of the second bonding ring 33 can be formed with the barrier wall structure 32, or the inner side and the outer side of the second bonding ring 33 can be formed with the barrier wall structure 32; the barrier wall structure 32 can be a ring structure.

[0178] And, the barrier wall structure 32 can also be used as a support structure for controlling the bonding reaction, and the height of the barrier wall structure 32 can be set according to the required bonding degree. Wherein, at the initial stage of bonding, there is still a certain gap between the side of the barrier wall structure 32 away from the second substrate 31 and the semiconductor layer 23, and with the progress of the bonding reaction, the gap is continuously reduced, and when the side of the barrier wall structure 32 away from the second substrate 31 contacts the surface of the semiconductor layer 23, it indicates that the bonding reaction has reached the required degree of bonding, and then the bonding process stops.

[0179] The MEMS device can include at least one of a microphone, a resonator, a gyroscope, an infrared sensor, an accelerometer, and a magnetometer.

[0180] From the above, the MEMS device of the application, when the MEMS device is powered on for testing, since the side of the movable mass 232 close to the first substrate 21 is formed with the first insulating medium layer 222, and the first insulating medium layer 222 serves as the first anti-adhesion structure of the movable mass 232, so that when the movable mass 232 moves up and down, the first anti-adhesion structure can avoid adhesion between the movable mass 232 and the first substrate 21 under extreme conditions, and can keep insulation between the movable mass 232 and the first substrate 21 under extreme conditions through the first anti-adhesion structure; and since the end of the limiting structure 314 integrated with the second substrate 31 close to the semiconductor layer 23 is formed with the second insulating medium layer 312, and the second insulating medium layer 312 serves as the second anti-adhesion structure of the limiting structure 314, the second anti-adhesion structure is aligned with the movable mass 232, so that when the movable mass 232 moves up and down, the second anti-adhesion structure can avoid adhesion between the movable mass 232 and the limiting structure 314 under extreme conditions, and can keep insulation between the movable mass 232 and the limiting structure 314 under extreme conditions through the second anti-adhesion structure. Therefore, the MEMS device of the application can not only avoid adhesion between the movable mass and the structure above and below it, but also can insulate the movable mass from the structure above and below it, thereby avoiding the test charge from being led out, so as to avoid causing test failure, and improve the reliability of the device.

[0181] The above description is only the description of the preferred embodiments of the present application, and is not any limitation on the scope of the present application. Any change and modification made by the person skilled in the art according to the above disclosure is within the protection scope of the claims.

Claims

1. A method of manufacturing a MEMS device, characterized by, The method comprises: providing a first substrate, a sacrificial layer being formed on the first substrate; forming a first recess in the sacrificial layer; forming a first insulating medium layer to fill in the first recess; forming a semiconductor layer to cover the sacrificial layer, and the semiconductor layer covering the first insulating medium layer; etching the semiconductor layer and stopping on the sacrificial layer to form a release hole and a movable mass in the semiconductor layer; releasing part of the sacrificial layer through the release hole to form a first cavity, the first cavity exposing the first insulating medium layer and part of the first substrate, the first insulating medium layer being on a side of the movable mass close to the first substrate, so that the first insulating medium layer serves as a first anti-sticking structure of the movable mass; providing a second substrate; forming a second recess in the second substrate; forming a second insulating medium layer in the second recess; etching the second substrate around the second insulating medium layer to form a second cavity, the second substrate remaining under the second insulating medium layer serving as a limiting structure, and the second insulating medium layer serving as a second anti-sticking structure of the limiting structure; bonding a side of the semiconductor layer away from the first substrate to a side of the second substrate having the second cavity, and the second anti-sticking structure aligning with the movable mass.

2. The method of manufacturing a MEMS device according to claim 1, wherein The first substrate comprises a semiconductor base and a third insulating medium layer covering the semiconductor base, and a conductive structure connected with the semiconductor base is formed in the third insulating medium layer; the first cavity exposes the third insulating medium layer and the conductive structure, and the exposed conductive structure aligns with the first anti-sticking structure.

3. The method of manufacturing a MEMS device according to claim 1, wherein A height difference between a top surface of the first insulating medium layer and a top surface of the sacrificial layer around the first recess is less than 1500 angstroms.

4. The method of manufacturing a MEMS device according to claim 1, wherein A top surface of the second insulating medium layer is lower than a top surface of the second substrate around the second recess.

5. The method of manufacturing a MEMS device according to claim 1, wherein After etching the second substrate around the second insulating medium layer, the method further comprises: forming a gas absorption layer on a bottom wall of the second cavity.

6. The method of manufacturing a MEMS device according to claim 1, wherein After forming the semiconductor layer to cover the sacrificial layer and before etching the semiconductor layer and stopping on the sacrificial layer, the method further comprises: forming a first bonding ring on the semiconductor layer; After forming the second insulating medium layer in the second recess and before etching the second substrate around the second insulating medium layer, the method further comprises: forming a second bonding ring on the second substrate; The bonding of the side of the semiconductor layer away from the first substrate to the side of the second substrate having the second cavity comprises bonding the side of the semiconductor layer away from the first substrate to the side of the second substrate having the second cavity through the first bonding ring and the second bonding ring.

7. The method of manufacturing a MEMS device according to claim 6, wherein Before bonding the side of the semiconductor layer away from the first substrate to the side of the second substrate having the second cavity, the method further comprises: forming a spacer body on a surface of the second substrate close to the second bonding ring.

8. The method of manufacturing a MEMS device according to claim 7, wherein, After forming the spacer body on the surface of the second substrate close to the second bonding ring, the manufacturing method of the MEMS device further comprises: forming a spacer protection layer on a surface of the spacer body.

9. The method of manufacturing a MEMS device according to claim 8, wherein, The spacer body is formed simultaneously with the second insulating medium layer, and the spacer protection layer is formed simultaneously with the second bonding ring.

10. A MEMS device, characterized by comprises: a first substrate, a sacrificial layer and a semiconductor layer are formed on the first substrate, the semiconductor layer covers the sacrificial layer, a first cavity is formed in the sacrificial layer, a movable mass and a release hole are formed in the semiconductor layer, the release hole is in communication with the first cavity, a first insulating medium layer is formed on a side of the movable mass close to the first substrate, and the first cavity exposes the first insulating medium layer and part of the first substrate, and the first insulating medium layer serves as a first anti-adhesion structure of the movable mass; a second substrate is bonded to the semiconductor layer, a second cavity is formed on a side of the second substrate close to the semiconductor layer, the second cavity is in communication with the release hole, a limiting structure is formed in the second cavity, the limiting structure is an integral structure with the second substrate and extends towards the semiconductor layer, a second insulating medium layer is formed on an end of the limiting structure close to the semiconductor layer, and the second insulating medium layer serves as a second anti-adhesion structure of the limiting structure, and the second anti-adhesion structure is aligned with the movable mass.

11. The MEMS device of claim 10, wherein, The first substrate comprises a semiconductor base and a third insulating medium layer covering the semiconductor base, and a conductive structure connected with the semiconductor base is formed in the third insulating medium layer; the first cavity exposes the third insulating medium layer and the conductive structure, and the exposed conductive structure is aligned with the first anti-adhesion structure.

12. The MEMS device of claim 10, wherein, The height difference between a side of the first insulating medium layer away from the first substrate and a side of the sacrificial layer away from the first substrate is less than 1500 angstroms.

13. The MEMS device of claim 10, wherein, A side of the second insulating medium layer close to the semiconductor layer is higher than a side of the second substrate close to the semiconductor layer at the periphery of the second cavity.

14. The MEMS device of claim 10, wherein, The MEMS device further comprises: a gas absorption layer formed on a bottom wall of the second cavity.

15. The MEMS device of claim 10, wherein, The MEMS device further comprises: a first bonding ring formed on a side of the semiconductor layer away from the first substrate; a second bonding ring formed on a side of the second substrate close to the semiconductor layer, and a side of the semiconductor layer away from the first substrate and a side of the second substrate close to the semiconductor layer are bonded through the first bonding ring and the second bonding ring.

16. The MEMS device of claim 15, wherein, The MEMS device further comprises: a spacer body formed on a surface of the second substrate close to the second bonding ring.

17. The MEMS device of claim 16, wherein, The MEMS device further comprises: a spacer protection layer formed on a surface of the spacer body.

18. The MEMS device of claim 17, wherein, The spacer body and the second insulating medium layer are made of the same material, and the spacer protection layer and the second bonding ring are made of the same material.

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