CN213847011U

CN213847011U - MEMS sensor chip, microphone and electronic device

Info

Publication number: CN213847011U
Application number: CN202023206703.XU
Authority: CN
Inventors: 刘松; 邱冠勋; 周宗燐
Original assignee: Goertek Microelectronics Inc
Current assignee: Goertek Microelectronics Inc
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2021-07-30
Anticipated expiration: 2030-12-25

Abstract

The utility model discloses a MEMS sensor chip, microphone and electronic equipment. The MEMS sensor chip comprises a substrate, a sensing assembly and an annular protection layer, wherein the substrate is provided with a cavity, the sensing assembly comprises a first annular supporting layer, a second annular supporting layer, a third annular supporting layer, a vibrating diaphragm, a first back plate with a first through hole and a second back plate with a second through hole, the first annular supporting layer is arranged on the substrate, the first annular supporting layer, the first back plate, the second annular supporting layer, the vibrating diaphragm, the third annular supporting layer and the second back plate are sequentially stacked in the direction departing from the substrate, the annular protection layer is arranged on the periphery of the sensing assembly, and the annular protection layer at least covers the first annular supporting layer and/or the second annular supporting layer and/or the third annular supporting layer. In this way, the reliability of the first and/or second and/or third annular support layers may be ensured or provided.

Description

MEMS sensor chip, microphone and electronic device

Technical Field

The utility model relates to a sensor technical field, in particular to MEMS sensor chip, microphone and electronic equipment.

Background

A Micro-Electro-Mechanical System (MEMS) microphone is an acoustic-electric transducer manufactured by Micro-machining (MEMS) technology, and is widely applied to electronic devices such as mobile phones, tablet computers, cameras, hearing aids, intelligent toys, monitoring devices and the like due to its characteristics of small volume, good frequency response, low noise and the like. The MEMS microphone mainly comprises a packaging shell and an MEMS sensor chip arranged in the packaging shell, so that a sound signal is converted into an electric signal through the MEMS sensor chip.

At present, a MEMS sensor chip generally includes a substrate and a sensing component disposed on the substrate, where the sensing component includes a vibrating diaphragm and a back plate disposed opposite to each other, and the vibrating diaphragm and the back plate form a flat capacitor structure. The vibrating diaphragm vibrates under the action of sound waves, so that the distance between the vibrating diaphragm and the back plate is changed, the capacitance of the plate capacitor is changed, and sound wave signals are converted into electric signals.

In the preparation process of the MEMS sensor chip, sacrificial layers (mostly oxide layers) are arranged between a sensing component and a substrate and between a vibrating diaphragm and a back plate of the sensing component, and then part of the sacrificial layers are corroded by corrosive liquids such as HF acid or BOE solution and the like to release the micro-motor structure; the remaining sacrificial layer typically serves as a support layer for the MEMS structure to support the sensing elements.

However, during the etching process, the sacrificial layer is easily etched and transited, so that the reliability of the supporting layer is low, and the reliability of the MEMS sensor chip and the microphone is low.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a MEMS sensor chip aims at solving current MEMS sensor chip preparation technology, the lower technical problem of reliability of micromotor structure's supporting layer.

In order to achieve the above object, the present invention provides a MEMS sensor chip, including:

a substrate having a cavity;

the induction assembly comprises a first annular supporting layer, a second annular supporting layer, a third annular supporting layer, a vibrating diaphragm, a first back plate with a first through hole and a second back plate with a second through hole, wherein the first annular supporting layer is arranged on the substrate, the first back plate is arranged on one side, away from the substrate, of the first annular supporting layer, the second annular supporting layer is arranged on one side, away from the substrate, of the first back plate, the vibrating diaphragm is arranged on one side, away from the substrate, of the second annular supporting layer, the third annular supporting layer is arranged on one side, away from the substrate, of the vibrating diaphragm, and the second back plate is arranged on one side, away from the substrate, of the third annular supporting layer; and

the annular protective layer is arranged on the peripheral side of the induction assembly and at least covers the first annular supporting layer and/or the second annular supporting layer and/or the third annular supporting layer.

Optionally, the annular protection layer sequentially covers the first annular supporting layer, the first back plate, the second annular supporting layer, the diaphragm, the third annular supporting layer, and the second back plate.

Optionally, the second back plate comprises a first conductive layer and a first protective layer;

the first conducting layer is arranged on one side, away from the substrate, of the third annular supporting layer, and the first protective layer is arranged on one side, away from the substrate, of the first conducting layer; alternatively, the first and second electrodes may be,

the first protective layer is arranged on one side, away from the substrate, of the third annular supporting layer, and the first conductive layer is arranged on one side, away from the substrate, of the first protective layer.

Optionally, the annular protective layer is integrally connected with the first conductive layer.

Optionally, the first back plate comprises a second conductive layer and a second protective layer which are stacked; and the number of the first and second electrodes,

the first back plate further comprises an isolating ring, and the isolating ring is arranged between the first conducting layer and the annular protective layer; alternatively, the first and second electrodes may be,

the second conducting layer is connected with the annular protective layer, the first conducting layer is provided with a first annular isolating hole, and the second back plate further comprises an isolating piece at least partially arranged in the first annular isolating hole; alternatively, the first and second electrodes may be,

the second conducting layer is connected with the annular protective layer, the second conducting layer is provided with a second annular isolation hole, and the second protective layer comprises an annular isolation convex part arranged in the second annular isolation hole.

Optionally, the annular protection layer is integrally connected with the first protection layer; and/or the presence of a gas in the gas,

the annular protective layer is integrally connected with the second protective layer of the first back plate.

Optionally, the second back plate includes a third protective layer, a third conductive layer, and a fourth protective layer, where the third protective layer is disposed on a side of the third annular supporting layer away from the substrate, the third conductive layer is disposed on a side of the third protective layer away from the substrate, and the fourth protective layer is disposed on a side of the third conductive layer away from the substrate.

Optionally, the annular protective layer is integrally connected with the third conductive layer.

Optionally, the first back plate includes a fifth protective layer, a fourth conductive layer, and a sixth protective layer that are sequentially stacked; and the number of the first and second electrodes,

the first back plate further comprises an isolating ring, and the isolating ring is arranged between the fourth conducting layer and the annular protective layer; alternatively, the first and second electrodes may be,

the second back plate further comprises a first annular isolation part which is arranged in the third annular isolation hole and is connected with the third protective layer and the fourth protective layer; alternatively, the first and second electrodes may be,

the fourth conducting layer is connected with the annular protective layer, the fourth conducting layer is provided with a fourth annular isolating hole, and the first back plate further comprises a second annular isolating part which is arranged in the fourth annular isolating hole and connected with the fifth protective layer and the sixth protective layer.

Optionally, the annular protective layer is integrally connected with the third protective layer and/or the fourth protective layer.

Optionally, the periphery of the diaphragm and the annular protection layer are spaced, and the second annular supporting layer and the third annular supporting layer are connected into a whole through the space between the periphery of the diaphragm and the annular protection layer.

Optionally, the outer annular surface of the annular protection layer is a stepped surface; and/or the presence of a gas in the gas,

and the vibrating diaphragm is provided with a pressure relief hole.

The utility model discloses still provide a microphone, include:

a package housing; and

the MEMS sensor chip as described above, the MEMS sensor chip is disposed within the package housing.

The utility model also provides an electronic equipment, include as above the microphone.

The utility model discloses in, set up the annular protective layer that covers first annular supporting layer and/or second annular supporting layer and/or third annular supporting layer at least through the outside at the response subassembly for the annular protective layer can be protected first annular supporting layer and/or second annular supporting layer and/or the outer peripheral edges of third annular supporting layer, in order to avoid it to be corroded at the preparation in-process, thereby can guarantee or provide the reliability of first annular supporting layer and/or second annular supporting layer and/or third annular supporting layer, thereby can improve the performance and the reliability of microphone, improve the yield of MEMS sensor chip and microphone.

Moreover, the first back plate and the second back plate are respectively arranged on two sides of the vibrating diaphragm, so that the vibrating diaphragm and the first back plate form a first parallel plate capacitor, the vibrating diaphragm and the second back plate form a second parallel plate capacitor, and the first parallel plate capacitor and the second parallel plate capacitor are subjected to differential control, so that not only can the sensitivity of the MEMS sensor chip be improved, but also the signal-to-noise ratio of the MEMS sensor chip can be improved, and the performance of the MEMS sensor chip can be improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a first embodiment of a MEMS sensor chip according to the present invention;

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

fig. 3 is a schematic structural diagram of a second embodiment of the MEMS sensor chip of the present invention;

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

fig. 5 is a schematic structural diagram of a fourth embodiment of the MEMS sensor chip of the present invention;

fig. 6 is a schematic structural diagram of a fifth embodiment of the MEMS sensor chip of the present invention;

fig. 7 is a schematic structural diagram of a sixth embodiment of the MEMS sensor chip of the present invention;

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

fig. 9 is a schematic structural diagram of an eighth embodiment of the MEMS sensor chip of the present invention.

The reference numbers illustrate:

the objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that if the embodiments of the present invention are described with reference to "first", "second", etc., the description of "first", "second", etc. is only for descriptive purposes and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

In addition, the meaning of "and/or" appearing throughout is to include three juxtapositions, exemplified by "A and/or B" including either scheme A, or scheme B, or a scheme in which both A and B are satisfied.

The utility model provides a MEMS sensor chip, mainly used microphone.

In an embodiment of the present invention, as shown in fig. 1, and 3-9, the MEMS sensor chip 100 includes a substrate 10, a sensing component, and an annular protection layer 30.

Wherein, as shown in fig. 1, and 3-9, the substrate 10 has a cavity 11, and the cavity 11 penetrates through the substrate 10.

As shown in fig. 1, and 3-9, the sensing assembly includes a first ring-shaped supporting layer 21, a second ring-shaped supporting layer 23, a third ring-shaped supporting layer 25, a diaphragm 24, a first back plate 22 having a first through hole 221, and a second back plate 26 having a second through hole 261, where the first ring-shaped supporting layer 21 is disposed on the substrate 10, the first back plate 22 is disposed on a side of the first ring-shaped supporting layer 21 away from the substrate 10, the second ring-shaped supporting layer 23 is disposed on a side of the first back plate 22 away from the substrate 10, the diaphragm 24 is disposed on a side of the second ring-shaped supporting layer 23 away from the substrate 10, the third ring-shaped supporting layer 25 is disposed on a side of the diaphragm 24 away from the substrate 10, and the second back plate 26 is disposed on a side of the third ring-shaped supporting layer 25 away from the substrate 10.

In short, as shown in fig. 1, and 3 to 9, the first annular support layer 21 is provided on the substrate 10, and the first annular support layer 21, the first back plate 22, the second annular support layer 23, the diaphragm 24, the third annular support layer 25, and the second back plate 26 are sequentially stacked in a direction away from the substrate 10.

Specifically, as shown in fig. 1, and 3-9, the annular hole of the first annular supporting layer 21 is disposed corresponding to the cavity 11, and the annular hole of the first annular supporting layer 21 is communicated with the cavity 11; the annular hole of the second annular supporting layer 23 is arranged corresponding to the annular hole of the first annular supporting layer 21, and the first through hole 221 on the first back plate 22 is communicated with the annular hole of the second annular supporting layer 23 and the annular hole of the first annular supporting layer 21; the annular hole of the third annular supporting layer 25 is arranged corresponding to the annular hole of the second annular supporting layer 23, and the second through hole 261 on the second back plate 26 is communicated with the annular hole of the third annular supporting layer 25.

Specifically, the first through hole 221 and/or the second through hole 261 may be provided in one or more than one (i.e., two or more) number. In this embodiment, the first through holes 221 and the second through holes 261 are arranged in a plurality at intervals on the corresponding back plate, and the number of the first through holes 221 and the number of the second through holes 261 are equivalent.

Specifically, the diaphragm 24 is provided with a pressure relief hole (not shown). Alternatively, the pressure relief hole may be provided in one or more (i.e., two or more). In this embodiment, the plurality of pressure relief holes are arranged at intervals on the diaphragm 24.

Specifically, the diameter or equivalent diameter of the pressure relief holes may be smaller than the diameter or equivalent diameter of the first through holes 221, and the number of the pressure relief holes may be smaller than the number of the first through holes 221.

Specifically, the first through hole 221 and the second through hole 261 can be used as a sound hole, a pressure relief hole, and a corrosion hole. Specifically, when the MEMS sensor chip 100 is manufactured, the first via hole 221 and the second via hole 261 function as etching holes through which an etching liquid passes to facilitate removal of the second sacrificial layer b and the third sacrificial layer c; when the microphone is assembled or assembled on a main control board of the electronic device, the first through hole 221 can be used as a pressure relief hole; the first and second through

holes

221 and 261 may serve as sound holes for transmitting sound to the diaphragm 24 when in operation.

The annular protection layer 30 is disposed on the peripheral side of the sensing assembly, and the annular protection layer 30 at least covers the first annular support layer 21, the second annular support layer 23, and/or the third annular support layer 25. In this way, it is possible to facilitate the protection of the first annular supporting layer 21 and/or of the second annular supporting layer 23 and/or of said third annular supporting layer 25, so as to guarantee/improve the reliability thereof.

Specifically, the diaphragm 24 and the first back plate 22 may form a first parallel plate capacitor, the diaphragm 24 and the second back plate 26 may form a second parallel plate capacitor, and differential control may be performed on the first parallel plate capacitor and the second parallel plate capacitor, so as to improve performance of the MEMS sensor chip 100. Specifically, in operation, the diaphragm 24 vibrates under the action of sound waves, which causes the distances between the diaphragm 24 and the first and

second back plates

22 and 26 to change, so that the capacitances of the first and second parallel-plate capacitors change, and the sound wave signals are converted into two electrical signals.

In order to facilitate the detailed explanation of the function of the annular protection layer 30, the present invention further provides a manufacturing process of the sensor chip, which is as follows:

1. a first sacrificial layer a, a first back plate 22, a second sacrificial layer b, a diaphragm 24, a third sacrificial layer c, and a second back plate 26 are sequentially (deposited) formed on the substrate 10, wherein a first through hole 221 is formed on the first back plate 22, and a second through hole 261 is formed on the second back plate 26.

2. As shown in fig. 2, an annular protection layer 30 is formed on the peripheral sides (deposited) of the first sacrificial layer a, the first back plate 22, the second sacrificial layer b, the diaphragm 24, the third sacrificial layer c and the second back plate 26, and the annular protection layer 30 covers at least the first sacrificial layer a, the second sacrificial layer b and/or the third sacrificial layer c.

3. Removing part of the first sacrificial layer a, the second sacrificial layer b and the third sacrificial layer c (by a method of wet etching or vapor phase HF fumigation by using an etching solution such as HF acid or BOE solution) to release the micro-electromechanical structure; meanwhile, the remaining first sacrificial layer a forms a first ring-shaped support layer 21, the remaining second sacrificial layer b forms a second ring-shaped support layer 23, and the remaining third sacrificial layer c forms a third ring-shaped support layer 25.

During the process of removing the portions of the first, second and third sacrificial layers a, b and c, since the annular protection layer 30 covers at least the first, second and/or third sacrificial layers a, b and/or c, the outer periphery of the first sacrificial layer a may not be removed/corroded, and/or the outer periphery of the second sacrificial layer b may not be removed/corroded, and/or the outer periphery of the third sacrificial layer c may not be removed/corroded, so that the annular protection layer 30 may protect the outer periphery of the first and/or second sacrificial layers a, b and/or c, and may avoid excessive corrosion of the first and/or second sacrificial layers a, b and/or c, and thus may ensure or provide reliable first and/or second and/or third annular support layers 21, 23 and/or 25 Thereby improving the performance and reliability of the microphone and increasing the yield of the MEMS sensor chip 100 and the microphone.

That is, the annular protection layer 30 may protect the outer periphery of the first annular support layer 21, the second annular support layer 23, and/or the third annular support layer 25 from being corroded during the manufacturing process, so that the reliability of the first annular support layer 21, the second annular support layer 23, and/or the third annular support layer 25 may be ensured or provided, thereby improving the performance and reliability of the microphone, and increasing the yield of the MEMS sensor chip 100 and the microphone.

Moreover, by respectively disposing the first back plate 22 and the second back plate 26 on two sides of the diaphragm 24, the diaphragm 24 and the first back plate 22 can form a first parallel plate capacitor, and the second back plate 26 can form a second parallel plate capacitor, and by performing differential control on the first parallel plate capacitor and the second parallel plate capacitor, not only the sensitivity of the MEMS sensor chip 100 can be improved, but also the signal-to-noise ratio of the MEMS sensor chip 100 can be improved, so that the performance of the MEMS sensor chip 100 can be improved.

In this embodiment, the annular protective layer 30 covers at least the first, second, and third annular support layers 21, 23, and 25 to ensure the reliability of the first, second, and third annular support layers 21, 23, and 25.

In some embodiments, as shown in fig. 1, and 3-9, the outer annular surface of the annular protection layer 30 may be a stepped surface. In this embodiment, optionally, the outer peripheries of the third annular supporting layer 25, the second back plate 26 and the diaphragm 24 may be flush, the second annular supporting layer 23 protrudes radially (i.e., in a direction away from the center line of the substrate 10) from the diaphragm 24, the first back plate 22 protrudes radially (i.e., in a direction away from the center line of the substrate 10) from the second annular supporting layer 23, and the first annular supporting layer 21 protrudes radially (i.e., in a direction away from the center line of the substrate 10) from the first back plate 22, so that the shape of the peripheral side of the inductive component is a stepped structure, and the shape of the annular protection layer 30 is adapted to the shape of the peripheral side of the inductive component, so that the thickness of the annular protection layer 30 is relatively uniform, so as to ensure the protection effect, that the outer annular surface of the annular protection layer 30 may be a stepped surface. In other embodiments, the outer annular surface of the annular protection layer 30 may be a flat surface.

In an embodiment, as shown in fig. 1, and 3-9, the annular protection layer 30 may be sequentially covered on the first annular support layer 21, the first back plate 22, the second annular support layer 23, the diaphragm 24, the third annular support layer 25, and the second back plate 26 in a direction away from the substrate 10. Specifically, one end of the annular protection layer 30 is hermetically connected to the upper surface of the substrate 10, and the other end covers the second back plate 26. It should be noted that the annular protection layer 30 may cover the periphery of the second back plate 26 completely or partially, as will be described below by way of example.

In an embodiment, the material of the annular protection layer 30 may be the same as that of the conductive layer of the second back plate 26 (for example, polysilicon may be selected), may be the same as that of the protection layer of the second back plate 26 (for example, silicon nitride may be selected), and may also be different from that of the second back plate 26; however, it should be different from the first sacrificial layer a, the second sacrificial layer b and the third sacrificial layer c (for example, the first sacrificial layer a and/or the second sacrificial layer b may be silicon oxide, etc.) to avoid corrosion of the annular protection layer 30 during the preparation process, which is exemplified below.

In a specific embodiment, the back plate (the first back plate 22 and/or the second back plate 26) may be a double-layer film structure, that is, the back plate includes a conductive layer and a protective layer which are stacked, and the through hole sequentially penetrates through the conductive layer and the protective layer; the back plate comprises a conducting layer and two protective layers which are arranged in a laminated mode, the conducting layer is located between the two protective layers, and the through hole penetrates through the conducting layer and the two protective layers; in the following, the description mainly takes "the first back plate 22 and the second back plate 26 are both of a double-layer film structure" or "the first back plate 22 and the second back plate 26 are both of a three-layer film structure" as an example, but the case of "one of the first back plate 22 and the second back plate 26 is a double-layer film structure, and the other is a three-layer film structure" is not excluded. Of course, in some embodiments, the back plate may also be a single-layer conductive layer structure.

It should be noted that, when the second back plate 26 is configured as a double-layer film structure (in this case, the second back plate 26 includes the first conductive layer 262 and the first protective layer 263), the first conductive layer 262 may be disposed on a side of the third ring-shaped support layer 25 facing away from the substrate 10, and the first protective layer 263 is disposed on a side of the first conductive layer 262 facing away from the substrate 10; it is also possible to provide the first protective layer 263 on the side of the third ring-shaped support layer 25 facing away from the substrate 10 and to provide the first conductive layer 262 on the side of the first protective layer 263 facing away from the substrate 10. In the following, the description will be given by taking an example that the first protective layer 263 is disposed on the side of the third ring-shaped support layer 25 facing away from the substrate 10, and the first conductive layer 262 is disposed on the side of the first protective layer 263 facing away from the substrate 10.

When the first back plate 22 is configured as a double-layer film structure (in this case, the first back plate 22 includes the second conductive layer 222 and the second protective layer 223), the second conductive layer 222 may be disposed on a side of the first annular support layer 21 away from the substrate 10, the second protective layer 223 may be disposed on a side of the second conductive layer 222 away from the substrate 10, and the second annular support layer 23 is disposed on a side of the second protective layer 223 away from the substrate 10; it is also possible to provide the second protective layer 223 on a side of the first annular support layer 21 facing away from the substrate 10, to provide the second conductive layer 222 on a side of the second protective layer 223 facing away from the substrate 10, and to provide the second annular support layer 23 on a side of the second conductive layer 222 facing away from the substrate 10. In the following, the description will be given by taking an example that the second conductive layer 222 is provided on the side of the first annular support layer 21 facing away from the substrate 10, the second protective layer 223 is provided on the side of the second conductive layer 222 facing away from the substrate 10, and the second annular support layer 23 is provided on the side of the second protective layer 223 facing away from the substrate 10.

When the second back plate 26 is configured as a three-layer film structure (in this case, the second back plate 26 includes the third protection layer 265, the third conductive layer 264 and the fourth protection layer 266), the third protection layer 265 may be disposed on a side of the third annular support layer 25 away from the substrate 10, the third conductive layer 264 may be disposed on a side of the third protection layer 265 away from the substrate 10, and the fourth protection layer 266 may be disposed on a side of the third conductive layer 264 away from the substrate 10.

When the first back plate 22 is configured as a three-layer film structure (at this time, the first back plate 22 includes a fifth protective layer 225, a fourth conductive layer 224 and a sixth protective layer 226), the fifth protective layer 225 may be disposed on a side of the first annular supporting layer 21 away from the substrate 10, the fourth conductive layer 224 is disposed on a side of the fifth protective layer 225 away from the substrate 10, the sixth protective layer 226 is disposed on a side of the fourth conductive layer 224 away from the substrate 10, and the second annular supporting layer 23 is disposed on a side of the sixth protective layer 226 away from the substrate 10.

In the specific embodiment, the annular protection layer 30 may be integrally connected to the conductive layer of the second back plate 26, the annular protection layer 30 may be integrally connected to the protection layer of the second back plate 26, or the annular protection layer 30 may be separately connected to the second back plate 26, which will be described below by way of example.

In some embodiments, as shown in fig. 1 and 3, the annular protective layer 30 is integrally connected to the protective layer of the second backplate 26. In this way, the annular protection layer 30 can be formed (deposited) when the protection layer of the second back plate 26 is formed (deposited), so that the manufacturing process of the MEMS sensor chip 100 can be simplified.

In the first embodiment of the MEMS sensor chip 100 of the present invention, as shown in fig. 1, the second back plate 26 is configured as a double-layer film structure, and for example, the second back plate 26 includes a first conductive layer 262 and a first protective layer 263, and the first protective layer 263 is disposed on the side of the third annular supporting layer 25 away from the substrate 10, and the first conductive layer 262 is disposed on the side of the first protective layer 263 away from the substrate 10; the first via 221 sequentially penetrates through the first conductive layer 262 and the first protective layer 263. Optionally, the first conductive layer 262 is made of a conductive material, such as polysilicon; the first protection layer 263 is made of an insulating material, such as silicon nitride.

In this embodiment, further, as shown in fig. 1, the annular protective layer 30 is integrally connected to the first protective layer 263. Specifically, the annular protection layer 30 is made of an insulating material, such as silicon nitride. That is, the annular protective layer 30 is an insulating protective layer. In this way, the diaphragm 24, the first back plate 22 and the second back plate 26 are prevented from being short-circuited by the annular protection layer 30, so as to ensure that the first parallel plate capacitor and the second parallel plate capacitor form a differential capacitance structure.

In this embodiment, further, as shown in fig. 1, the first back plate 22 is provided as a double-layer film structure, for example, the first back plate 22 includes a second conductive layer 222 and a second protective layer 223, and the second conductive layer 222 is provided on the side of the first annular support layer 21 facing away from the substrate 10, the second protective layer 223 is provided on the side of the second conductive layer 222 facing away from the substrate 10, and the second annular support layer 23 is provided on the side of the second protective layer 223 facing away from the substrate 10; the second through hole 261 sequentially penetrates the second conductive layer 222 and the second protective layer 223. Optionally, the second conductive layer 222 is made of a conductive material, such as polysilicon; the second passivation layer 223 is made of an insulating material, such as silicon nitride.

In this embodiment, further, as shown in fig. 1, the annular protective layer 30 is integrally connected to the second protective layer 223 of the first back plate 22.

In this embodiment, the periphery of the diaphragm 24 may be disposed at a distance from (the inner surface of) the annular protective layer 30, or the periphery of the diaphragm 24 may extend to (the inner surface of) the annular protective layer 30.

In the second embodiment of the MEMS sensor chip 100 of the present invention, as shown in fig. 3, the second back plate 26 is configured as a three-layer film structure, that is, the second back plate 26 includes a third protection layer 265, a third conductive layer 264 and a fourth protection layer 266, and the third protection layer 265 is disposed on one side of the third ring-shaped support layer 25 away from the substrate 10, the third conductive layer 264 is disposed on one side of the third protection layer 265 away from the substrate 10, and the fourth protection layer 266 is disposed on one side of the third conductive layer 264 away from the substrate 10; the first via hole 221 sequentially penetrates through the third protective layer 265, the third conductive layer 264, and the fourth protective layer 266. Optionally, the third conductive layer 264 is made of a conductive material, such as polysilicon; the third protection layer 265 and the fourth protection layer 266 are made of an insulating material, such as silicon nitride.

In this embodiment, further, as shown in fig. 3, the annular protective layer 30 is integrally connected with the third protective layer 265 and/or the fourth protective layer 266. Alternatively, the annular protective layer 30 is integrally connected to the third protective layer 265 and the fourth protective layer 266, respectively. Specifically, the annular protection layer 30 is made of an insulating material, such as silicon nitride. That is, the annular protective layer 30 is an insulating protective layer. In this way, the diaphragm 24, the first back plate 22 and the second back plate 26 are prevented from being short-circuited by the annular protection layer 30, so as to ensure that the first parallel plate capacitor and the second parallel plate capacitor form a differential capacitance structure.

In this embodiment, as further shown in fig. 3, the first back plate 22 is configured as a three-layer film structure, that is, the first back plate 22 includes a fifth protective layer 225, a fourth conductive layer 224 and a sixth protective layer 226, the fifth protective layer 225 is disposed on a side of the first annular support layer 21 facing away from the substrate 10, the fourth conductive layer 224 is disposed on a side of the fifth protective layer 225 facing away from the substrate 10, the sixth protective layer 226 is disposed on a side of the fourth conductive layer 224 facing away from the substrate 10, and the second annular support layer 23 is disposed on a side of the sixth protective layer 226 facing away from the substrate 10. Optionally, the fourth conductive layer 224 is made of a conductive material, such as polysilicon; the fifth passivation layer 225 and the sixth passivation layer 226 are made of an insulating material, such as silicon nitride.

In this embodiment, further, as shown in fig. 3, the annular protective layer 30 is integrally connected with the fifth protective layer 225 and/or the sixth protective layer 226.

In yet another partial embodiment, as shown in fig. 4-9, the annular protective layer 30 is integrally connected to the conductive layer of the second back plate 26. In this way, the annular protection layer 30 can be formed (deposited) when the conductive layer of the second back plate 26 is formed (deposited), so that the manufacturing process of the MEMS sensor chip 100 can be simplified.

In the third embodiment of the present invention, as shown in fig. 4, the second back plate 26 is provided as a double-layer film structure, and for example, the second back plate 26 includes a first conductive layer 262 and a first protective layer 263 which are stacked, and the first protective layer 263 is provided on the side of the third annular supporting layer 25 which is away from the substrate 10, and the first conductive layer 262 is provided on the side of the first protective layer 263 which is away from the substrate 10; the first via 221 sequentially penetrates through the first conductive layer 262 and the first protective layer 263. Optionally, the first conductive layer 262 is made of a conductive material, such as polysilicon; the first protection layer 263 is made of an insulating material, such as silicon nitride.

In this embodiment, further, as shown in fig. 4, the annular protective layer 30 is integrally connected to the first conductive layer 262. Specifically, the material of the annular protection layer 30 is a conductive material, such as polysilicon.

In this embodiment, further, as shown in fig. 4, the periphery of the diaphragm 24 is spaced from (the inner surface of) the annular protective layer 30 to avoid the diaphragm 24 from being short-circuited with the first back plate 22 and/or the second back plate 26 through the annular protective layer 30.

In this embodiment, further, as shown in fig. 4, the second ring-shaped support layer 23 and the third ring-shaped support layer 25 are integrally connected through a space between the periphery of the diaphragm 24 and (the inner surface of) the ring-shaped protective layer 30. Thus, the reliability of the second ring support layer 23 and the third ring support layer 25 can be improved.

In this embodiment, further, as shown in fig. 4, the first back plate 22 is provided as a double-layer film structure, for example, the first back plate 22 includes a second conductive layer 222 and a second protective layer 223 which are stacked, and the second conductive layer 222 is provided on a side of the first annular support layer 21 facing away from the substrate 10, the second protective layer 223 is provided on a side of the second conductive layer 222 facing away from the substrate 10, and the second annular support layer 23 is provided on a side of the second protective layer 223 facing away from the substrate 10; the second through hole 261 sequentially penetrates the second conductive layer 222 and the second protective layer 223. Optionally, the second conductive layer 222 is made of a conductive material, such as polysilicon; the second passivation layer 223 is made of an insulating material, such as silicon nitride.

In this embodiment, as shown in fig. 4, the second conductive layer 222 is integrally or separately connected to the annular protection layer 30, the first conductive layer 262 has a first annular isolation hole, and the second back plate 26 further includes an isolator 267 at least partially disposed in the first annular isolation hole. Specifically, the spacers 267 are made of an insulating material, such as silicon nitride. Thus, the first conductive layer 262 and the second conductive layer 222 can be prevented from being short-circuited through the ring-shaped protection layer 30.

In this embodiment, the cross-sectional shape of the separator 267 is optionally T-shaped, as shown in fig. 4.

In this embodiment, optionally, as shown in fig. 4, the separator 267 is an annular structure.

In the fourth embodiment of the present invention, as shown in fig. 5, the main difference between this embodiment and the third embodiment of the present invention is that the structure for preventing the first conductive layer 262 and the second conductive layer 222 from being short-circuited through the annular protective layer 30 is different.

In this embodiment, as shown in fig. 5, the periphery of the second conductive layer 222 is spaced from (the inner surface of) the annular protection layer 30 to prevent the first conductive layer 262 and the second conductive layer 222 from being short-circuited through the annular protection layer 30.

In this embodiment, as shown in fig. 5, the first back plate 22 further includes a spacer ring 227, and the spacer ring 227 is disposed between the second conductive layer 222 and the annular protection layer 30. Specifically, the isolation ring 227 is made of an insulating material, such as silicon nitride. Thus, isolation can be better achieved.

In this embodiment, the isolation ring 227 may be integrally connected to the second protection layer 223, or may be separately provided. Preferably, the isolation ring 227 is integrally connected with the second protective layer 223.

In the fifth embodiment of the present invention, as shown in fig. 6, the main difference between this embodiment and the third and fourth embodiments of the present invention is that the structure for preventing the first conductive layer 262 and the second conductive layer 222 from being short-circuited through the annular protective layer 30 is different.

In this embodiment, as shown in fig. 6, the second conductive layer 222 is connected to the annular protection layer 30, the second conductive layer 222 has a second annular isolation hole, and the second protection layer 223 includes an annular isolation convex 2231 disposed in the second annular isolation hole. Thus, the first conductive layer 262 and the second conductive layer 222 are prevented from being short-circuited through the ring-shaped passivation layer 30.

The above-described configuration for preventing the first conductive layer 262 and the second conductive layer 222 from being short-circuited through the ring-shaped protective layer 30 may be combined with each other when they are not contradictory or unrealizable.

In a sixth embodiment of the present invention, as shown in fig. 7, the main difference between this embodiment and the third, fourth and fifth embodiments of the present invention is that the second back plate 26 is provided as a three-layer film structure.

In this embodiment, as shown in fig. 7, the second back plate 26 includes a third protection layer 265, a third conductive layer 264 and a fourth protection layer 266, and the third protection layer 265 is disposed on a side of the third annular support layer 25 facing away from the substrate 10, the third conductive layer 264 is disposed on a side of the third protection layer 265 facing away from the substrate 10, and the fourth protection layer 266 is disposed on a side of the third conductive layer 264 facing away from the substrate 10; the first via hole 221 sequentially penetrates through the third protective layer 265, the third conductive layer 264, and the fourth protective layer 266. Optionally, the third conductive layer 264 is made of a conductive material, such as polysilicon; the third protection layer 265 and the fourth protection layer 266 are made of an insulating material, such as silicon nitride.

In this embodiment, further, as shown in fig. 7, the annular protective layer 30 is integrally connected to the third conductive layer 264. Specifically, the material of the annular protection layer 30 is a conductive material, such as polysilicon.

In this embodiment, further, as shown in fig. 7, the periphery of the diaphragm 24 is spaced from (the inner surface of) the annular protective layer 30 to avoid the diaphragm 24 from being short-circuited with the first back plate 22 and/or the second back plate 26 through the annular protective layer 30.

In this embodiment, further, as shown in fig. 7, the second ring-shaped support layer 23 and the third ring-shaped support layer 25 are integrally connected through a space between the periphery of the diaphragm 24 and (the inner surface of) the ring-shaped protective layer 30. Thus, the reliability of the support layer can be improved.

In this embodiment, as shown in fig. 7, the first back plate 22 is configured as a three-layer film structure, that is, the first back plate 22 includes a fifth protective layer 225, a fourth conductive layer 224 and a sixth protective layer 226, the fifth protective layer 225 is disposed on a side of the first annular support layer 21 facing away from the substrate 10, the fourth conductive layer 224 is disposed on a side of the fifth protective layer 225 facing away from the substrate 10, the sixth protective layer 226 is disposed on a side of the fourth conductive layer 224 facing away from the substrate 10, and the second annular support layer 23 is disposed on a side of the sixth protective layer 226 facing away from the substrate 10. Optionally, the fourth conductive layer 224 is made of a conductive material, such as polysilicon; the fifth passivation layer 225 and the sixth passivation layer 226 are made of an insulating material, such as silicon nitride.

In this embodiment, further, as shown in fig. 7, the fourth conductive layer 224 is connected with the annular protection layer 30, such as integrally or separately connected; and the third conductive layer 264 has a third annular isolation hole, and the second back plate 26 further includes a first annular isolation portion 268 disposed in the third annular isolation hole and connecting the third protection layer 265 and the fourth protection layer 266. Specifically, the first annular isolation portion 268 is made of an insulating material, such as silicon nitride. Thus, the third conductive layer 264 and the fourth conductive layer 224 can be prevented from being short-circuited through the annular protection layer 30.

In the seventh embodiment of the present invention, as shown in fig. 8, the main difference between this embodiment and the sixth embodiment of the present invention is that the structure for preventing the third conductive layer 264 and the fourth conductive layer 224 from being short-circuited through the annular protective layer 30 is different.

In this embodiment, as shown in fig. 8, the periphery of the fourth conductive layer 224 is spaced from (the inner surface of) the annular protection layer 30 to avoid short-circuiting between the third conductive layer 264 and the fourth conductive layer 224 through the annular protection layer 30.

In this embodiment, as shown in fig. 8, the first back plate 22 further includes a spacer ring 227, and the spacer ring 227 is disposed between the fourth conductive layer 224 and the annular protection layer 30. Specifically, the isolation ring 227 is made of an insulating material, such as silicon nitride. Thus, isolation can be better achieved.

In this embodiment, the isolation ring 227 is optionally connected with the fifth protective layer 225 and the sixth protective layer 226, respectively.

In the eighth embodiment of the present invention, as shown in fig. 9, the main difference between this embodiment and the sixth and seventh embodiments of the present invention is that the structure for preventing the third conductive layer 264 and the fourth conductive layer 224 from being short-circuited through the annular protective layer 30 is different.

In this embodiment, as shown in fig. 9, the fourth conductive layer 224 is connected to the annular protection layer 30, the fourth conductive layer 224 has a fourth annular isolation hole, and the first back plate 22 further includes a second annular isolation portion 228 disposed in the fourth annular isolation hole and connecting the fifth protection layer 225 and the sixth protection layer 226. Thus, the third conductive layer 264 and the fourth conductive layer 224 can be prevented from being short-circuited through the ring-shaped passivation layer 30.

In addition, the above-described structural schemes for preventing the third conductive layer 264 and the fourth conductive layer 224 from being short-circuited through the ring-shaped protective layer 30 may be combined with each other when they are not contradictory or unrealizable.

Of course, in a specific embodiment, the annular protection layer 30 may be provided in other structural forms to realize "at least cover the first annular support layer 21, the second annular support layer 23, and/or the third annular support layer 25".

For example, the annular protective layer 30 may include a first protective ring layer covering the first annular support layer 21 and a second protective ring layer covering the second annular support layer 23 and the third annular support layer 25; and so on.

In addition, it should be specifically noted that the technical solutions in the above embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model discloses still provide a microphone, include:

a package housing; and

This MEMS sensor chip's concrete structure refers to above-mentioned embodiment, because the utility model discloses the microphone has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, no longer gives unnecessary details here.

The utility model also provides an electronic equipment, this electronic equipment include main control board and microphone, the microphone is connected with the main control board electricity. The concrete structure of this microphone refers to above-mentioned embodiment, because the utility model discloses electronic equipment has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, no longer gives unnecessary details here.

The electronic equipment can be selected from electronic equipment such as a mobile phone, a tablet personal computer, a camera, a hearing aid, an intelligent toy or a monitoring device.

The above is only the optional embodiment of the present invention, and not the scope of the present invention is limited thereby, all the equivalent structure changes made by the contents of the specification and the drawings are utilized under the inventive concept of the present invention, or the direct/indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A MEMS sensor chip, comprising:

a substrate having a cavity;

2. The MEMS sensor chip of claim 1, wherein the annular protective layer sequentially covers the first annular support layer, the first back plate, the second annular support layer, the diaphragm, the third annular support layer, and the second back plate.

3. The MEMS sensor chip of claim 2, wherein the second back plate comprises a first conductive layer and a first protective layer;

4. The MEMS sensor chip of claim 3, wherein the annular protective layer is integrally connected with the first conductive layer.

5. The MEMS sensor chip of claim 4, wherein the first back plate comprises a second conductive layer and a second protective layer disposed in a stack; and the number of the first and second electrodes,

6. The MEMS sensor chip of claim 3, wherein the annular protective layer is integrally connected with the first protective layer; and/or the presence of a gas in the gas,

7. The MEMS sensor chip of claim 2, wherein the second back plate comprises a third protective layer, a third conductive layer, and a fourth protective layer, the third protective layer being disposed on a side of the third ring-shaped support layer facing away from the substrate, the third conductive layer being disposed on a side of the third protective layer facing away from the substrate, and the fourth protective layer being disposed on a side of the third conductive layer facing away from the substrate.

8. The MEMS sensor chip of claim 7, wherein the annular protective layer is integrally connected with the third conductive layer.

9. The MEMS sensor chip of claim 8, wherein the first back plate comprises a fifth protective layer, a fourth conductive layer, and a sixth protective layer sequentially stacked; and the number of the first and second electrodes,

10. The MEMS sensor chip of claim 7, wherein the annular protective layer is integrally connected with the third protective layer and/or the fourth protective layer.

11. The MEMS sensor chip of any one of claims 2 to 10, wherein the periphery of the diaphragm is spaced apart from the annular protective layer, and the second annular supporting layer and the third annular supporting layer are integrally connected through the space between the periphery of the diaphragm and the annular protective layer.

12. The MEMS sensor chip of any one of claims 2 to 10, wherein an outer annular surface of the annular protective layer is a stepped surface; and/or the presence of a gas in the gas,

and the vibrating diaphragm is provided with a pressure relief hole.

13. A microphone, comprising:

a package housing; and

the MEMS sensor chip of any one of claims 1 to 12, disposed within the package housing.

14. An electronic device comprising the microphone of claim 13.