WO2022135003A1

WO2022135003A1 - Mems sensor chip, microphone, and electronic device

Info

Publication number: WO2022135003A1
Application number: PCT/CN2021/132768
Authority: WO
Inventors: 邱冠勋; 刘松; 周宗燐
Original assignee: 歌尔微电子股份有限公司
Priority date: 2020-12-25
Filing date: 2021-11-24
Publication date: 2022-06-30
Also published as: CN213847003U

Abstract

Disclosed are an MEMS sensor chip, a microphone and an electronic device. The MEMS sensor chip comprises a substrate, an induction assembly and an annular protective layer, wherein the substrate has a cavity; the induction assembly comprises a first annular support layer, a second annular support layer, a vibrating diaphragm, and a back plate which has a through hole; the first annular support layer is arranged on the substrate; the first annular support layer, the back plate, the second annular support layer and the vibrating diaphragm are sequentially stacked in a direction away from the substrate; the annular protective layer is arranged on a peripheral side of the induction assembly; and the annular protective layer at least covers the first annular support layer and/or the second annular support layer.

Description

MEMS sensor chips, microphones and electronics

This application claims the priority of the Chinese patent application with application number 202023206702.5 filed on December 25, 2020, the entire contents of which are incorporated herein by reference.

technical field

The present application relates to the field of sensor technology, and in particular, to a MEMS sensor chip, a microphone and an electronic device.

Background technique

MEMS (Micro-Electro-Mechanical System) microphone is an acousto-electric transducer made by micro-machining (MEMS) technology. Because of its small size, good frequency response characteristics and low noise, it is widely used in mobile phones such as mobile phones. , tablet computers, cameras, hearing aids, smart toys and electronic devices such as surveillance devices. The MEMS microphone mainly includes a package shell and a MEMS sensor chip arranged in the package shell, so as to convert the sound signal into an electrical signal through the MEMS sensor chip.

At present, a MEMS sensor chip usually includes a substrate and a sensing component disposed on the substrate. The sensing component includes a diaphragm and a back plate opposite to each other, and a flat capacitive structure composed of the diaphragm and the back plate. Among them, the diaphragm vibrates under the action of sound waves, which causes the distance between the diaphragm and the back plate to change, so that the capacitance of the plate capacitor changes, thereby converting the sound wave signal into an electrical signal.

In the process of preparing MEMS sensor chips, a sacrificial layer (mostly an oxide layer) is set between the sensing component and the substrate, as well as between the diaphragm and the back plate of the sensing component, and then the sacrificial layer is passed through HF acid or BOE. A corrosive solution such as a solution is used to etch away part of the sacrificial layer to release the micro-motor structure; the remaining sacrificial layer is usually used as a support layer of the micro-motor structure to support the induction components.

However, during the etching process, the sacrificial layer is easily etched and transitioned, resulting in lower reliability of the support layer, thereby lowering the reliability of the MEMS sensor chip and the microphone.

technical problem

The main purpose of this application is to propose a MEMS sensor chip, which aims to solve the technical problem of low reliability of the support layer of the micro-motor structure in the existing MEMS sensor chip preparation process.

technical solutions

To achieve the above purpose, the present application proposes a MEMS sensor chip, comprising:

a substrate having a cavity;

an induction assembly, the induction assembly includes a first annular support layer, a second annular support layer, a vibrating film and a back plate with a through hole, the first annular support layer is arranged on the substrate, the back electrode The plate is arranged on the side of the first annular support layer away from the substrate, the second annular support layer is arranged at the side of the back plate away from the substrate, and the diaphragm is arranged on the side of the back plate away from the substrate. a side of the second annular support layer facing away from the substrate; and

An annular protective layer, the annular protective layer is provided on the peripheral side of the induction component, and the annular protective layer covers at least the first annular support layer and/or the second annular support layer.

In one embodiment, the annular protective layer sequentially covers the first annular support layer, the back plate, the second annular support layer, and the diaphragm.

In one embodiment, the annular protective layer is integrally connected with the diaphragm.

In one embodiment, the vibrating membrane includes an annular connecting portion integrally connected with the annular protective layer, and a vibrating portion disposed inside the annular connecting portion, the vibrating portion and the annular connecting portion being spaced apart.

In one embodiment, the diaphragm further includes a spacer, and the spacer is at least partially disposed in the interval between the vibration portion and the annular connecting portion.

In one embodiment, the annular protective layer is an insulating protective layer.

In one embodiment, the back plate includes a conductive layer and a first protective layer;

The conductive layer is arranged on the side of the first annular support layer away from the substrate, the first protective layer is arranged on the side of the conductive layer away from the substrate, and the second annular support layer is arranged on the side away from the substrate. The support layer is provided on the side of the first protective layer away from the substrate; or,

The first protective layer is disposed on the side of the first annular support layer away from the substrate, the conductive layer is disposed on the side of the first protective layer away from the substrate, and the first protective layer is disposed on the side of the first annular support layer away from the substrate. Two annular support layers are arranged on the side of the conductive layer facing away from the substrate.

In one embodiment, the back plate further includes an isolation ring, and the isolation ring is provided between the conductive layer and the annular protective layer; or,

The conductive layer has an annular isolation hole, and the first protective layer includes an annular isolation convex portion arranged in the annular isolation hole.

In one embodiment, the back plate includes a conductive layer, a first protective layer and a second protective layer, the first protective layer is provided on a side of the first annular support layer away from the substrate, The conductive layer is arranged on the side of the first protective layer away from the substrate, the second protective layer is arranged on the side of the conductive layer away from the substrate, and the second annular support A layer is provided on a side of the second protective layer facing away from the substrate.

The outer periphery of the first protective layer is integrally connected with the outer periphery of the second protective layer; or,

The conductive layer has an annular isolation hole, and the back plate further includes an annular isolation portion arranged in the annular isolation hole and connected to the first protection layer and the second protection layer.

In one embodiment, the outer annular surface of the annular protective layer is a stepped surface.

In one embodiment, the annular protection layer includes a first protection ring layer and a second protection ring layer, the first protection ring layer covers the first annular support layer, and the second protection ring layer covers the The second annular support layer.

In one embodiment, the first guard ring layer is integrally connected with the conductive layer of the back plate; and/or,

The second guard ring layer is integrally connected with the diaphragm.

The present application also proposes a microphone, which includes:

an encapsulation case; and

In the above-mentioned MEMS sensor chip, the MEMS sensor chip is provided in the package casing.

The present application also proposes an electronic device, which includes the above-mentioned microphone.

beneficial effect

In this application, an annular protective layer covering at least the first annular supporting layer and/or the second annular supporting layer is provided on the outside of the induction assembly, so that the annular protective layer can protect the first annular supporting layer and/or the second annular supporting layer. The outer periphery of the MEMS sensor chip is protected from corrosion during the preparation of the MEMS sensor chip, thereby ensuring or providing the reliability of the first annular support layer and/or the second annular support layer, thereby improving the performance and reliability of the microphone , improve the yield of MEMS sensor chips and microphones.

Moreover, by arranging the back plate close to the substrate, the distance between the sensing component and the substrate can be reduced, that is, the thickness of the first annular support layer can be reduced, thereby facilitating the realization of miniaturized design.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a first embodiment of a MEMS sensor chip of the present application;

FIG. 2 is a schematic structural diagram of the MEMS sensor chip in FIG. 1 before being etched;

3 is a schematic structural diagram of a second embodiment of the MEMS sensor chip of the present application;

FIG. 4 is a schematic structural diagram of a third embodiment of the MEMS sensor chip of the present application;

5 is a schematic structural diagram of a fourth embodiment of the MEMS sensor chip of the present application;

6 is a schematic structural diagram of a fifth embodiment of the MEMS sensor chip of the present application;

7 is a schematic structural diagram of a sixth embodiment of the MEMS sensor chip of the present application;

FIG. 8 is a schematic structural diagram of a seventh embodiment of the MEMS sensor chip of the present application;

FIG. 9 is a schematic structural diagram of an eighth embodiment of the MEMS sensor chip of the present application;

FIG. 10 is a schematic structural diagram of a ninth embodiment of the MEMS sensor chip of the present application.

Description of reference numbers:

标号 label	名称 name	标号 label	名称 name
100 100	MEMS传感器芯片 MEMS sensor chip	23 twenty three	第二环形支撑层 second annular support layer
10 10	衬底 substrate	24 twenty four	振膜 Diaphragm
11 11	空腔 cavity	241 241	环形连接部 Ring connection
21 twenty one	第一环形支撑层 first annular support layer	242 242	振动部 Vibration Department
22 twenty two	背极板 back plate	243 243	隔离件 spacer
221 221	通孔 through hole	30 30	环形保护层 ring protective layer
222 222	导电层 conductive layer	31 31	限位翻边 Limit flanging
223 223	第一保护层 first protective layer	32 32	第一保护环层 first guard ring layer
2231 2231	环形隔离凸部 annular isolation bump	33 33	第二保护环层 second guard ring layer
224 224	第二保护层 second protective layer	a a	第一牺牲层 first sacrificial layer
225 225	隔离环 isolation ring	b b	第二牺牲层 second sacrificial layer
226 226	环形隔离部 annular spacer

The realization, functional characteristics and advantages of the purpose of the present application will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Embodiments of the present invention

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of this application, the descriptions of "first", "second", etc. are only used for description purposes, and should not be construed as instructions or Implicit their relative importance or implicitly indicate the number of technical features indicated. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature.

In addition, the meaning of "and/or" in the whole text is to include three parallel schemes. Taking "A and/or B" as an example, it includes scheme A, scheme B, or scheme that A and B satisfy at the same time.

This application proposes a MEMS sensor chip, which is mainly used for microphones.

In an embodiment of the present application, as shown in FIGS. 1 and 3-10 , the MEMS sensor chip 100 includes a substrate 10 , a sensing component and an annular protective layer 30 .

As shown in FIGS. 1 and 3-10 , the substrate 10 has a cavity 11 , and the cavity 11 penetrates the substrate 10 .

As shown in FIGS. 1 and 3-10 , the sensing assembly includes a first annular support layer 21 , a second annular support layer 23 , a diaphragm 24 and a back plate 22 having a through hole 221 . The first annular support layer 21 is arranged on the substrate 10, the back plate 22 is arranged on the side of the first annular supporting layer 21 away from the substrate 10, and the second annular supporting layer 23 is arranged on the backing liner of the back plate 22 On one side of the bottom 10 , the diaphragm 24 is disposed on the side of the second annular support layer 23 away from the substrate 10 . In short, the first annular support layer 21 is disposed on the substrate 10 , and the first annular support layer 21 , the back plate 22 , the second annular support layer 23 and the diaphragm 24 are away from the substrate 10 . are arranged in layers in the direction of the .

Specifically, as shown in FIGS. 1 and 3-10 , the annular holes of the first annular support layer 21 are arranged corresponding to the cavity 11 , and the annular holes of the first annular support layer 21 are communicated with the cavity 11 ; The annular holes of the second annular support layer 23 are arranged corresponding to the annular holes of the first annular support layer 21 , and the through holes 221 on the back plate 22 communicate with the annular holes of the second annular support layer 23 and the first annular support layer 21 . ring hole.

Specifically, the through hole 221 may be provided in one or a plurality of through holes (ie, greater than or equal to two). In this embodiment, a plurality of the through holes 221 are arranged on the back plate 22 at intervals.

Specifically, the through holes 221 can be used as sound holes, pressure relief holes and corrosion holes. Specifically, when preparing the MEMS sensor chip 100, the through hole 221 is used as an etching hole for the etching liquid to pass through, so as to facilitate the removal of the second sacrificial layer b; when assembling the microphone or assembling the microphone on the main control board of the electronic device When working, the through hole 221 can be used as a pressure relief hole; when working, the through hole 221 can be used as a sound hole for transmitting sound to the diaphragm 24 .

Wherein, the annular protective layer 30 is disposed on the peripheral side of the induction assembly, and the annular protective layer 30 at least covers the first annular support layer 21 and/or the second annular support layer 23 . In this way, it is convenient to protect the first annular support layer 21 and/or the second annular support layer 23 to ensure/improve their reliability.

Specifically, the diaphragm 24 and the back plate 22 form a parallel plate capacitor. During operation, the diaphragm 24 vibrates under the action of sound waves, which causes the distance between the diaphragm 24 and the back plate 22 to change, so that the capacitance of the parallel plate capacitor changes, thereby converting the sound wave signal into an electrical signal.

In order to facilitate the detailed description of the function of the annular protective layer 30, the present application also provides a preparation process of the sensor chip, which is as follows:

1. A first sacrificial layer a, a back plate 22 , a second sacrificial layer b, and a diaphragm 24 are sequentially (deposited) formed on the substrate 10 , wherein the back plate 22 is formed with a through hole 221 .

2. As shown in FIG. 2, an annular protective layer 30 is formed on the peripheral side (deposited) of the first sacrificial layer a, the back plate 22, the second sacrificial layer b and the diaphragm 24, and the annular protective layer 30 covers at least the the first sacrificial layer a and/or the second sacrificial layer b.

3. Remove part of the first sacrificial layer a and the second sacrificial layer b (by wet etching or gas-phase HF fumigation with corrosive solutions such as HF acid or BOE solution) to release the micro-motor structure; The sacrificial layer a forms a first annular supporting layer 21 , and the remaining second sacrificial layer b forms a second annular supporting layer 23 .

In the process of removing part of the first sacrificial layer a and the second sacrificial layer b, since the annular protective layer 30 covers at least the first sacrificial layer a and/or the second sacrificial layer b, the outer periphery of the first sacrificial layer a can be removed. will not be removed/etched, and/or, the outer periphery of the second sacrificial layer b may not be removed/etched, so that the ring-shaped protective layer 30 can realize the protection of the first sacrificial layer a and/or the second sacrificial layer b Protect the outer periphery of the first sacrificial layer a and/or the second sacrificial layer b from excessive corrosion, thereby ensuring or providing the reliability of the first annular support layer 21 and/or the second annular support layer 23, thereby The performance and reliability of the microphone can be improved, and the yield of the MEMS sensor chip 100 and the microphone can be improved.

That is, the annular protective layer 30 can protect the outer periphery of the first annular support layer 21 and/or the second annular support layer 23 from being corroded during the manufacturing process, thereby ensuring or providing the first annular support The reliability of the layer 21 and/or the second annular support layer 23 can be improved, thereby improving the performance and reliability of the microphone, and improving the yield of the MEMS sensor chip 100 and the microphone.

Moreover, by arranging the back plate 22 close to the substrate 10 , the distance between the sensing component and the substrate 10 can be reduced, that is, the thickness of the first annular support layer 21 can be reduced, and the miniaturization can be achieved. design.

In this embodiment, the annular protective layer 30 covers at least the first annular support layer 21 and the second annular support layer 23 to ensure or provide the reliability of the first annular support layer 21 and the second annular support layer 23 .

Further, as shown in FIGS. 1 and 3-10 , the outer annular surface of the annular protective layer 30 is a stepped surface.

Specifically, as shown in FIGS. 1 and 3-10 , the back plate 22 protrudes from the second annular support layer 23 radially (ie, in a direction away from the centerline of the substrate 10 ), and the first annular support The layer 21 protrudes from the back plate 22 radially (ie, in the direction away from the centerline of the substrate 10 ), so that the shape of the peripheral side of the sensing component is a stepped structure, and the shape of the annular protective layer 30 is the same as that of the sensing component. The shape of the peripheral side is suitable, so that the thickness of the annular protective layer 30 is relatively uniform, so as to ensure the protection effect. Therefore, the outer annular surface of the annular protective layer 30 is a stepped surface.

Of course, in other embodiments, the outer ring surface of the annular protective layer 30 can also be a flat surface.

In a specific embodiment, as shown in FIGS. 1 and 3-10 , the annular protective layer 30 can cover the first annular support layer 21 , the back plate 22 , the second annular support layer 23 and the diaphragm 24 in sequence. . Specifically, one end of the annular protective layer 30 is hermetically connected to the upper surface of the substrate 10 , and the other end covers the diaphragm 24 .

In a specific embodiment, the material of the annular protective layer 30 may be the same as the material of the diaphragm 24 (for example, both can be selected as polysilicon), or may be different from the material of the diaphragm 24 (for example, the annular protective layer 30 is made of insulating material). , such as silicon nitride, etc., the vibrating film 24 is made of polysilicon), but it should be different from the material of the first sacrificial layer a and the second sacrificial layer b (for example, the first sacrificial layer a and/or the second sacrificial layer b may be selected as silicon oxide, etc.) to prevent the ring-shaped protective layer 30 from being corroded during the preparation process, which will be described with an example below.

In a specific embodiment, the back electrode plate 22 can be configured as a double-layer film structure, that is, the back electrode plate 22 includes a conductive layer 222 and a first protective layer 223 arranged in layers, and the through holes 221 penetrate the conductive layer 222 in sequence. and the first protective layer 223; it can also be set to a three-layer film structure, that is, the back plate 22 includes a first protective layer 223, a conductive layer 222 and a second protective layer 224 that are stacked and arranged, and the through holes 221 sequentially penetrate through the first protective layer 223. The protective layer 223, the conductive layer 222 and the second protective layer 224; the following examples are used for description. Of course, in some embodiments, the back plate 22 can also be a single-layer conductive layer 222 structure.

It should be noted that, when the back plate 22 is provided with a double-layer film structure, the conductive layer 222 can be provided on the side of the first annular support layer 21 away from the substrate 10, and the A protective layer 223 is provided on the side of the conductive layer 222 away from the substrate 10, and the second annular support layer 23 is provided on the side of the first protective layer 223 away from the substrate 10; The layer 223 is provided on the side of the first annular support layer 21 away from the substrate 10, the conductive layer 222 is provided on the side of the first protective layer 223 away from the substrate 10, and the second annular support layer 23 is provided on the side of the first protective layer 223 away from the substrate 10. The side of the conductive layer 222 facing away from the substrate 10 . Hereinafter, "the conductive layer 222 is provided on the side of the first annular support layer 21 away from the substrate 10, and the first protective layer 223 is provided on the side of the conductive layer 222 away from the substrate 10" as an example Be explained.

When the back plate 22 is configured as a three-layer film structure, the first protective layer 223 can be disposed on the side of the first annular support layer 21 away from the substrate 10 , and the conductive layer 222 can be disposed on the first protective layer The side of the layer 223 facing away from the substrate 10, the second protective layer 224 is provided on the side of the conductive layer 222 facing away from the substrate 10, the second annular support layer 23 is provided on the backing liner of the second protective layer 224 side of bottom 10.

In some embodiments, as shown in FIGS. 1 and 3-7 , the annular protective layer 30 is integrally connected with the diaphragm 24 . In this way, when the diaphragm 24 is formed (deposited), the annular protective layer 30 can be formed (deposited) together, so that the fabrication process of the MEMS sensor chip 100 can be simplified.

In the first embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 1 , the back plate 22 is configured as a double-layer film structure, for example, the back plate 22 includes a conductive layer 222 and a first protective layer 223 , and the first protective layer 223 is disposed on the side of the first annular support layer 21 away from the substrate 10, the conductive layer 222 is disposed on the side of the first protective layer 223 away from the substrate 10, the first Two annular support layers 23 are disposed on the side of the conductive layer 222 away from the substrate 10 .

In this embodiment, further, as shown in FIG. 1 , the periphery of the conductive layer 222 is spaced from (the inner surface of) the annular protective layer 30 to prevent the conductive layer 222 from being short-circuited with the annular protective layer 30 , thereby preventing conductive Layer 222 is shorted to diaphragm 24 through annular protective layer 30 .

In this embodiment, further, as shown in FIG. 1 , the back plate 22 further includes an isolation ring 225 , and the isolation ring 225 is provided between the conductive layer 222 and the annular protective layer 30 . Specifically, the isolation ring 225 is made of insulating material, and the isolation ring 225 is located in the interval between the periphery of the conductive layer 222 and the (inner surface of the annular protective layer 30 ). In this way, better isolation can be achieved to prevent short circuits.

In this embodiment, the isolation ring 225 may be a separate component, or may be integrally connected with the first protective layer 223 .

In this embodiment, the material of the diaphragm 24 can be selected from polysilicon or the like, the material of the annular protective layer 30 can be selected from polysilicon or the like, and the material of the conductive layer 222 can be selected from polysilicon or the like.

In this embodiment, the material of the first protective layer 223 can be selected from silicon nitride or the like, and the material of the first annular support layer 21 and/or the second annular support layer 23 can be selected from silicon oxide or the like.

In the second embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 3 , the back plate 22 is configured as a double-layer film structure, for example, the back plate 22 includes a conductive layer 222 and a first protective layer 223 , and the first protective layer 223 is disposed on the side of the first annular support layer 21 away from the substrate 10, the conductive layer 222 is disposed on the side of the first protective layer 223 away from the substrate 10, the first Two annular support layers 23 are disposed on the side of the conductive layer 222 away from the substrate 10 .

In this embodiment, further, as shown in FIG. 3 , the conductive layer 222 has an annular isolation hole. Specifically, the annular isolation hole separates the conductive layer 222 into an outer ring portion integrally connected with the annular protective layer 30 and a conductive portion located inside the outer ring portion. In this way, the conductive portion can be prevented from being short-circuited with the annular protective layer 30 , thereby preventing the conductive portion from being short-circuited with the diaphragm 24 through the annular protective layer 30 .

In this embodiment, further, as shown in FIG. 3 , the first protective layer 223 includes an annular isolation protrusion 2231 disposed in the annular isolation hole. In this way, not only can better isolation be achieved to prevent short circuits, but also the structure can be simplified. It should be noted that, the annular isolation protrusion 2231 and the first protective layer 223 may also be provided separately.

In the third embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 4 , the diaphragm 24 includes an annular connecting portion 241 integrally connected with the annular protective layer 30 , and a vibrating portion disposed inside the annular connecting portion 241 . 242 , the vibrating part 242 and the annular connecting part 241 are arranged at intervals. In this way, the short circuit between the vibration part 242 and the annular protective layer 30 can be prevented, so that the short circuit between the vibration part 242 and the back plate 22 through the annular protective layer 30 can be prevented.

In this embodiment, further, as shown in FIG. 4 , the diaphragm 24 further includes a spacer 243 , and the spacer 243 is at least partially disposed in the interval between the vibration portion 242 and the annular connecting portion 241 . . Specifically, the spacer 243 is made of insulating material. In this way, better isolation can be achieved to prevent short circuits.

In this embodiment, as shown in FIG. 4 , the cross-sectional shape of the spacer 243 is T-shaped.

In this embodiment, as shown in FIG. 4 , the spacer 243 is an annular structure.

In this embodiment, as shown in FIG. 4 , the back plate 22 is configured as a double-layer film structure. For example, the back plate 22 includes a conductive layer 222 and a first protective layer 223 , and the first protective layer 223 is arranged on the side of the first annular support layer 21 away from the substrate 10, the conductive layer 222 is arranged on the side of the first protective layer 223 away from the substrate 10, and the second annular support layer 23 is arranged on the conductive layer 223. The side of layer 222 facing away from the substrate 10 .

In addition, it should be noted that the technical solutions between the above embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions contradicts or cannot be realized, it should be considered that such The combination of technical solutions does not exist and does not fall within the protection scope claimed in this application. For example, the vibrating membrane 24 may include the annular connecting portion 241 and the vibrating portion 242 arranged at intervals, and the periphery of the conductive layer 222 may be arranged at an interval from (the inner surface of the annular protective layer 30 ) or the conductive Layer 222 has annular isolation holes.

In the fourth embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 5 , the back plate 22 has a three-layer film structure, that is, the back plate 22 includes a conductive layer 222 , a first protective layer 223 and a The second protective layer 224, the first protective layer 223 is provided on the side of the first annular support layer 21 away from the substrate 10, and the conductive layer 222 is provided on the side of the first protective layer 223 away from the substrate 10 On one side, the second protective layer 224 is disposed on the side of the conductive layer 222 away from the substrate 10 , and the second annular support layer 23 is disposed on the side of the second protective layer 224 away from the substrate 10 .

In this embodiment, further, as shown in FIG. 5 , the periphery of the conductive layer 222 is spaced from (the inner surface of) the annular protective layer 30 to prevent the conductive layer 222 from being short-circuited with the annular protective layer 30 , thereby preventing the conductive layer 222 from being short-circuited. Layer 222 is shorted to diaphragm 24 through annular protective layer 30 .

In this embodiment, further, as shown in FIG. 5 , the back plate 22 further includes an isolation ring 225 , and the isolation ring 225 is provided between the conductive layer 222 and the annular protective layer 30 . Specifically, the isolation ring 225 is made of insulating material, and the isolation ring 225 is located in the interval between the periphery of the conductive layer 222 and the (inner surface of the annular protective layer 30 ). In this way, better isolation can be achieved to prevent short circuits.

In this embodiment, the isolation ring 225 may be a separate component, or may be integrally connected with the first protective layer 223 and/or the second protective layer 224 . It can be understood that when the isolation ring 225 is integrally connected with the first protective layer 223 and the second protective layer 224, respectively, the outer periphery of the first protective layer 223 and the outer periphery of the second protective layer 224 are Connect as one.

In this embodiment, the material of the first protective layer 223 and the second protective layer 224 can be selected from silicon nitride or the like, and the material of the first annular support layer 21 and/or the second annular support layer 23 can be selected from For silicon oxide, etc.

In the fifth embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 6 , the back plate 22 is a three-layer film structure, that is, the back plate 22 includes a conductive layer 222 , a first protective layer 223 and a The second protective layer 224, the first protective layer 223 is provided on the side of the first annular support layer 21 away from the substrate 10, and the conductive layer 222 is provided on the side of the first protective layer 223 away from the substrate 10 On one side, the second protective layer 224 is disposed on the side of the conductive layer 222 away from the substrate 10 , and the second annular support layer 23 is disposed on the side of the second protective layer 224 away from the substrate 10 .

In this embodiment, further, as shown in FIG. 6 , the conductive layer 222 has an annular isolation hole. Specifically, the annular isolation hole separates the conductive layer 222 into an outer ring portion integrally connected with the annular protective layer 30 and a conductive portion located inside the outer ring portion. In this way, the conductive portion can be prevented from being short-circuited with the annular protective layer 30 , thereby preventing the conductive portion from being short-circuited with the diaphragm 24 through the annular protective layer 30 .

In this embodiment, further, as shown in FIG. 6 , the back plate 22 further includes an annular isolation portion 226 disposed in the annular isolation hole and connected to the first protective layer 223 and the second protective layer 224 . In this way, better isolation can be achieved to prevent short circuits.

In the sixth embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 7 , the diaphragm 24 includes an annular connecting portion 241 integrally connected with the annular protective layer 30 , and a vibrating portion disposed inside the annular connecting portion 241 . 242 , the vibrating part 242 and the annular connecting part 241 are arranged at intervals. In this way, the short circuit between the vibration part 242 and the annular protective layer 30 can be prevented, so that the short circuit between the vibration part 242 and the back plate 22 through the annular protective layer 30 can be prevented.

In this embodiment, further, as shown in FIG. 7 , the diaphragm 24 further includes a spacer 243 , and the spacer 243 is at least partially disposed in the interval between the vibration portion 242 and the annular connecting portion 241 . . Specifically, the spacer 243 is made of insulating material. In this way, better isolation can be achieved to prevent short circuits.

In this embodiment, as shown in FIG. 7 , the cross-sectional shape of the spacer 243 is T-shaped.

In this embodiment, as shown in FIG. 7 , the spacer 243 is an annular structure.

In this embodiment, the back plate 22 has a three-layer film structure, that is, the back plate 22 includes a conductive layer 222 , a first protective layer 223 and a second protective layer 224 , and the first protective layer 223 is provided with On the side of the first annular support layer 21 facing away from the substrate 10, the conductive layer 222 is provided on the side of the first protective layer 223 facing away from the substrate 10, and the second protective layer 224 is provided on the conductive layer On the side of the second protective layer 222 facing away from the substrate 10 , the second annular support layer 23 is provided on the side of the second protective layer 224 facing away from the substrate 10 .

In addition, it should be noted that the technical solutions of the above fourth, fifth and sixth embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized It should be considered that such a combination of technical solutions does not exist and is not within the protection scope claimed in this application. For example, the vibrating membrane 24 may include the annular connecting portion 241 and the vibrating portion 242 arranged at intervals, and the periphery of the conductive layer 222 may be arranged at an interval from (the inner surface of the annular protective layer 30 ) or the conductive Layer 222 has annular isolation holes.

In some embodiments, as shown in FIGS. 8 and 9 , the annular protective layer 30 can also be an insulating protective layer. In this way, the short circuit between the diaphragm 24 and the back plate 22 through the annular protective layer 30 can be avoided. In this part of the embodiment, the material of the annular protective layer 30 can be selected from silicon nitride or the like. The following description will be made with reference to the specific structure of the back plate 22 .

In the seventh embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 8 , the annular protective layer 30 is an insulating protective layer, and the back plate 22 is configured as a double-layer film structure, as shown in the back plate 22 includes a conductive layer 222 and a first protective layer 223, and the first protective layer 223 is provided on the side of the first annular support layer 21 away from the substrate 10, and the conductive layer 222 is provided on the first protective layer 223. On the side facing away from the substrate 10 , the second annular support layer 23 is provided on the side of the conductive layer 222 facing away from the substrate 10 .

In this embodiment, specifically, as shown in FIG. 8 , one end of the annular protective layer 30 is provided with a limiting flange 31 , and the limiting flange 31 is provided on the side of the diaphragm 24 away from the substrate 10 .

In the eighth embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 9 , that is, the back plate 22 includes a conductive layer 222 , a first protective layer 223 and a second protective layer 224 , the first protective layer 223 is provided on the side of the first annular support layer 21 away from the substrate 10, the conductive layer 222 is provided on the side of the first protective layer 223 away from the substrate 10, and the second protective layer 224 is provided on the side of the substrate 10. A side of the conductive layer 222 facing away from the substrate 10 is provided, and the second annular support layer 23 is provided on a side of the second protective layer 224 facing away from the substrate 10 .

In this embodiment, specifically, as shown in FIG. 9 , one end of the annular protective layer 30 is provided with a limiting flange 31 , and the limiting flange 31 is provided with the side of the diaphragm 24 facing away from the substrate 10 .

Of course, in specific embodiments, the annular protective layer 30 can also be set in other structural forms, so as to “cover at least the first annular support layer 21 and/or the second annular support layer 23 ”.

As in the ninth embodiment of the MEMS sensor chip 100 of the present application, as shown in FIG. 10 , the annular protective layer 30 includes a first guard ring layer 32 and a second guard ring layer 33 , and the first guard ring layer 32 The first annular support layer 21 is covered, and the second guard ring layer 33 covers the second annular support layer 23 . In this way, the outer peripheries of the first annular support layer 21 and the second annular support layer 23 can also be protected to avoid corrosion during the preparation of the MEMS sensor chip 100, so that the first annular support layer 21 and the second annular support layer 23 can be guaranteed or provided. Reliability of the second annular support layer 23 .

In this embodiment, as shown in FIG. 10 , in an embodiment, the first guard ring layer 32 is integrally connected with the conductive layer 222 of the back plate 22 ; and/or the second guard ring The layer 33 is integrally connected with the diaphragm 24 to simplify the structure. Of course, the first guard ring layer 32 and/or the second guard ring layer 33 can also be configured as insulating protection layers.

In addition, it should be noted that the technical solutions between the above embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that this The combination of these technical solutions does not exist and is not within the scope of protection claimed in this application.

The present application also proposes a microphone, comprising:

packaging shell;

The specific structure of the MEMS sensor chip refers to the above-mentioned embodiments. Since the microphone of the present application adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here. Repeat.

The present application also proposes an electronic device, which includes a main control board and a microphone, and the microphone is electrically connected to the main control board. For the specific structure of the microphone, refer to the above-mentioned embodiments. Since the electronic device of the present application adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here. .

Wherein, the electronic device can be selected from electronic devices such as mobile phones, tablet computers, cameras, hearing aids, smart toys or listening devices.

The above descriptions are only optional embodiments of the present application and are not intended to limit the scope of the patent of the present application. Under the inventive concept of the present application, any equivalent structural transformations made by using the contents of the description and drawings of the present application, or direct/indirect Applications in other related technical fields are included in the scope of patent protection of this application.

Claims

A MEMS sensor chip, wherein the MEMS sensor chip includes:

a substrate having a cavity;

an induction assembly, the induction assembly includes a first annular support layer, a second annular support layer, a vibrating film and a back plate with a through hole, the first annular support layer is arranged on the substrate, the back electrode The plate is arranged on the side of the first annular support layer away from the substrate, the second annular support layer is arranged at the side of the back plate away from the substrate, and the diaphragm is arranged on the side of the back plate away from the substrate. a side of the second annular support layer facing away from the substrate; and

An annular protective layer, the annular protective layer is provided on the peripheral side of the induction component, and the annular protective layer covers at least the first annular support layer and/or the second annular support layer.
The MEMS sensor chip of claim 1, wherein the annular protective layer sequentially covers the first annular support layer, the back plate, the second annular support layer and the diaphragm.
The MEMS sensor chip of claim 2, wherein the annular protective layer is integrally connected with the diaphragm.
The MEMS sensor chip according to claim 3, wherein the vibrating film comprises an annular connecting portion integrally connected with the annular protective layer, and a vibrating portion disposed inside the annular connecting portion, the vibrating portion being connected to the The annular connecting parts are arranged at intervals.
The MEMS sensor chip of claim 4 , wherein the vibrating film further comprises a spacer, and the spacer is at least partially disposed in a space between the vibration part and the annular connecting part.
The MEMS sensor chip of claim 2, wherein the annular protective layer is an insulating protective layer.
The MEMS sensor chip according to any one of claims 2 to 6, wherein the back plate comprises a conductive layer and a first protective layer;

The conductive layer is arranged on the side of the first annular support layer away from the substrate, the first protective layer is arranged on the side of the conductive layer away from the substrate, and the second annular support layer is arranged on the side away from the substrate. The support layer is provided on the side of the first protective layer away from the substrate; or,

The first protective layer is disposed on the side of the first annular support layer away from the substrate, the conductive layer is disposed on the side of the first protective layer away from the substrate, and the first protective layer is disposed on the side of the first annular support layer away from the substrate. Two annular support layers are arranged on the side of the conductive layer facing away from the substrate.
The MEMS sensor chip according to claim 7, wherein the back plate further comprises an isolation ring, and the isolation ring is provided between the conductive layer and the annular protection layer; or,

The conductive layer has an annular isolation hole, and the first protective layer includes an annular isolation convex portion arranged in the annular isolation hole.
The MEMS sensor chip according to any one of claims 2 to 6, wherein the back plate comprises a conductive layer, a first protective layer and a second protective layer, and the first protective layer is provided on the first protective layer The side of the annular support layer facing away from the substrate, the conductive layer is provided on the side of the first protective layer facing away from the substrate, and the second protective layer is provided on the side of the conductive layer facing away from the substrate. one side of the substrate, and the second annular support layer is provided on the side of the second protective layer away from the substrate.
The MEMS sensor chip according to claim 9, wherein the back plate further comprises an isolation ring, and the isolation ring is provided between the conductive layer and the annular protection layer; or,

The outer periphery of the first protective layer is integrally connected with the outer periphery of the second protective layer; or,

The conductive layer has an annular isolation hole, and the back plate further includes an annular isolation portion arranged in the annular isolation hole and connected to the first protection layer and the second protection layer.
The MEMS sensor chip according to any one of claims 2 to 6, wherein the outer annular surface of the annular protective layer is a stepped surface.
The MEMS sensor chip of claim 1, wherein the annular protection layer comprises a first protection ring layer and a second protection ring layer, the first protection ring layer covers the first annular support layer, and the first protection ring layer Two guard ring layers cover the second annular support layer.
The MEMS sensor chip of claim 12, wherein the first guard ring layer is integrally connected with the conductive layer of the back plate; and/or,

The second guard ring layer is integrally connected with the diaphragm.
A microphone, wherein the microphone comprises:

an encapsulation case; and

The MEMS sensor chip according to any one of claims 1 to 13, wherein the MEMS sensor chip is provided in the package housing.
14. An electronic device, wherein the electronic device includes the microphone of claim 14.