CN119071705A - Micro-electromechanical condenser microphone and method for manufacturing micro-electromechanical condenser microphone - Google Patents

Abstract

A micro-electromechanical capacitance microphone comprises a substrate, a vibrating diaphragm, a back plate structure, a supporting structure and a second protection fence. The substrate is provided with a cavity and a plurality of flashboard structures, the cavity penetrates through the substrate, the flashboard structures extend from the inner wall of the cavity towards the center of the cavity, the vibrating diaphragm is arranged on the substrate in a vibrating mode and comprises a main deformation area and a non-main deformation area, the non-main deformation area surrounds the main deformation area, the main deformation area is provided with a bottom surface facing the cavity, a plurality of anti-collision stop blocks are formed on the bottom surface, a first protection fence is formed on the periphery of the non-main deformation area and fixed on the substrate, the backboard structure corresponds to the main deformation area and is arranged on the main deformation area, the main deformation area is arranged between the substrate and the backboard structure, a plurality of sound holes are formed on the backboard structure, the support structures are arranged on the backboard structure and penetrate through the periphery of the main deformation area and respectively abut against the flashboard structures, and a second protection fence is arranged on the substrate and covers part of the first protection fence.

Description

Micro-electromechanical capacitance microphone and manufacturing method thereof

Technical Field

The present invention relates to the field of microphone technologies, and in particular, to a Micro Electro MECHANICAL SYSTEM, MEMS (mems) condenser microphone and a method for manufacturing the mems condenser microphone.

Background

Microelectromechanical (MEMS) microphones are increasingly being required to have high sensitivity, high signal-to-noise ratio, wider dynamic range, and high structural reliability, but not only are there trade-offs between sensitivity and dynamic range, but also there are trade-offs between low air impedance (high backplate open ratio), high backplate stiffness, and large backplate electrode area, which can significantly affect the signal-to-noise ratio of the MEMS condenser microphone.

Specifically, in the microelectromechanical condenser microphone, if the sensitivity is high enough to collect a minute sound, the flexibility of the diaphragm is increased, that is, the diaphragm is easily deformed by the sound pressure, so that the allowable sound pressure level is reduced, and the dynamic range is narrowed. In contrast, if the rigidity of the diaphragm is increased, that is, the diaphragm is less prone to deformation caused by the sound pressure, so that the diaphragm is not prone to nonlinear deformation at a large volume, the distortion degree is small, the allowable sound pressure level is high, the dynamic range is widened, but the sensitivity is reduced, and the signal to noise ratio is directly affected by the reduction of the sensitivity. In addition, in order to improve the signal-to-noise ratio of the mems condenser microphone, consideration must be given to how to reduce noise sources, such as Johnson-Nyquist noise (Johnson-Nyquist noise) in a circuit, parasitic capacitance of mems structure coupling, air impedance, or acoustic pressure deformation caused by insufficient rigidity of a back plate.

Therefore, how to improve the structural design of the MEMS microphone to solve the decision dilemma of the traditional MEMS microphone that there is a high trade-off relationship among air impedance, backplate electrode area or backplate rigidity is sought by the current industry.

Disclosure of Invention

The invention provides a micro-electromechanical capacitance microphone and a manufacturing method thereof, wherein the micro-electromechanical capacitance microphone has higher rigidity of a back plate, and can greatly reduce air impedance so as to improve the signal-to-noise ratio of the micro-electromechanical capacitance microphone. Meanwhile, the MEMS capacitor microphone also has the advantage of good sensing efficiency.

The invention provides a micro-electromechanical capacitance microphone which comprises a substrate, a vibrating diaphragm, a back plate structure, a supporting structure and a second protection fence. The substrate is provided with a cavity and a plurality of flashboard structures, the cavity penetrates through the substrate, the flashboard structures extend from the inner wall of the cavity towards the center of the cavity, the vibrating diaphragm is arranged on the substrate in a vibrating mode and comprises a main deformation area and a non-main deformation area, the non-main deformation area surrounds the main deformation area, the main deformation area is provided with a bottom surface facing the cavity, a plurality of anti-collision stop blocks are formed on the bottom surface, a first protection fence is formed on the periphery of the non-main deformation area and fixed on the substrate, the backboard structure corresponds to the main deformation area and is arranged on the main deformation area, the main deformation area is arranged between the substrate and the backboard structure, a plurality of sound holes are formed on the backboard structure, the support structures are arranged on the backboard structure and penetrate through the periphery of the main deformation area and respectively abut against the flashboard structures, and a second protection fence is arranged on the substrate and covers part of the first protection fence.

In an embodiment of the present invention, the bump stop is adapted to be disposed around the periphery of each supporting structure.

In an embodiment of the invention, the back plate structure includes a back plate main body and a back plate electrode, the vibrating diaphragm is a vibrating electrode, a main deformation area of the vibrating diaphragm faces the back plate electrode, and an air gap exists between the main deformation area and the back plate electrode.

In an embodiment of the invention, the back plate structure further includes a plurality of anti-adhesion stoppers connected to the back plate electrode and protruding toward the main deformation region.

In an embodiment of the invention, the back plate structure further includes a reinforcing frame, and a plurality of support structures are connected together in a ring.

In an embodiment of the invention, the gate plate structure is uniformly distributed on the inner wall of the cavity in a centripetal shape.

In an embodiment of the present invention, the shape of the shutter structure is selected from one or a combination of an elongated shape, a circular shape, a ring shape, an oval shape, a honeycomb shape, a square shape, a triangle shape, and a polygon shape.

In an embodiment of the invention, a plurality of diaphragm through holes are formed on the diaphragm, and a plurality of support structures respectively pass through the diaphragm through holes.

The manufacturing method of the MEMS capacitive microphone comprises providing a substrate, forming a first sacrificial layer on the substrate, defining a plurality of first through holes, a plurality of anti-collision baffle block through holes and a fence groove on the first sacrificial layer, forming a diaphragm on the first sacrificial layer, wherein the diaphragm comprises a main deformation region and a non-main deformation region, the non-main deformation region surrounds the main deformation region, the positions of the plurality of first through holes and the plurality of anti-collision baffle block through holes correspond to the peripheral region of the main deformation region, partial diaphragm is filled into the plurality of anti-collision baffle block through holes to be suitable for forming a plurality of anti-collision baffle blocks on the bottom surface of the main deformation region, partial diaphragm is filled into the fence groove to be suitable for forming a first protective fence on the peripheral region of the non-main deformation region, the plurality of diaphragm through holes correspond to the first through holes respectively, forming a second sacrificial layer on the diaphragm, defining a plurality of second through holes and a plurality of predefined through holes on the second sacrificial layer, the positions of the plurality of predefined through holes correspond to the main deformation region respectively, forming a third sacrificial layer on the second sacrificial layer, the plurality of the second sacrificial layer corresponds to the second sacrificial layer, the plurality of anti-collision baffle block through holes are formed on the second sacrificial layer, the second sacrificial layer corresponds to the second protective fence is suitable for forming a plurality of anti-collision baffle block through holes on the back plate, the second protective layer is suitable for forming a plurality of anti-collision baffle block through holes, the anti-adhesion layer is formed on the back plate, the main body is suitable for being formed on the back plate, the anti-adhesion layer is formed, the anti-adhesion protective layer is suitable for forming a plurality of the anti-adhesion baffle plate, and is suitable for being adhered to be formed on the main body and a main body layer, the backboard main body and the backboard electrode form a backboard structure corresponding to the main deformation area, each supporting structure penetrates through each third through hole, each second through hole, each vibrating diaphragm through hole and each first through hole, the second protection fence is arranged in the fence groove and covers part of the first protection fence, a plurality of sound holes are formed in the backboard structure, a cavity and a plurality of flashboard structures are formed in the substrate, the cavity penetrates through the substrate, the flashboard structures extend from the inner wall of the cavity towards the center of the cavity, the flashboard structures respectively correspond to the supporting structures, and the first sacrificial layer, the second sacrificial layer and the third sacrificial layer are removed.

In an embodiment of the present invention, before the substrate forms the cavity and the plurality of gate structures, a polishing process is performed on a back surface of the substrate away from the first sacrificial layer, so as to thin the substrate.

In an embodiment of the present invention, the materials of the first sacrificial layer, the second sacrificial layer, and the third sacrificial layer are silicon oxide, silicon nitride, or a combination thereof.

In an embodiment of the invention, the diaphragm is a polysilicon layer, a metal layer, an insulating layer and a lamination of the polysilicon layer, or a lamination of the insulating layer and the metal layer.

The invention sets the best sensing area between the vibrating diaphragm and the backboard according to the deformation curve of the vibrating diaphragm, and only establishes a pavilion-like backboard structure in the best capacitance coupling area corresponding to the vibrating diaphragm and the backboard structure, and because the backboard structure is arranged in the center of the cavity of the substrate, the flashboard structure is designed on the periphery of the backboard structure and is matched with the supporting structure to form a support on the backboard structure and the flashboard structure. Besides the area reduction, the back plate structure can further improve the rigidity of the back plate due to the inward movement of the supporting position, and the back plate structure is not easy to generate synchronous deformation with the vibrating diaphragm under the action of sound pressure so as to influence the performance. And because the backboard structure is not arranged in the area except the optimal capacitive coupling, no extra air impedance is generated, and therefore the signal and signal-to-noise ratio degradation of the vibrating diaphragm is not affected.

The foregoing description is only an overview of the present invention, and is intended to be implemented in accordance with the teachings of the present invention, as well as the preferred embodiments thereof, together with the following detailed description of the invention, given by way of illustration only, together with the accompanying drawings.

Drawings

Fig. 1A to 1K are schematic cross-sectional views illustrating a method for manufacturing a microelectromechanical condenser microphone according to an embodiment of the invention.

Fig. 2 is a schematic top view of a mems condenser microphone according to an embodiment of the invention.

FIG. 3 is a schematic top view of a cavity and silicon wafer structure in accordance with one embodiment of the present invention.

Fig. 4A and fig. 4B are schematic top views of a microelectromechanical condenser microphone according to another embodiment of the invention.

Fig. 5 is a schematic partial cross-sectional view of a first protective fence and a second protective fence according to another embodiment of the present invention.

Detailed Description

Fig. 1A to 1K are schematic cross-sectional views illustrating a method for manufacturing a microelectromechanical condenser microphone according to an embodiment of the invention. As shown in fig. 1A, a substrate 10 is provided. In particular, substrate 10 is used to provide a process platform for the formation of microelectromechanical condenser microphones, and the material of substrate 10 may be a silicon substrate, a germanium substrate, a silicon carbide substrate, a silicon-on-insulator substrate, a germanium-on-insulator substrate, a glass substrate, a III-V compound substrate (e.g., a gallium nitride substrate or a gallium arsenide-based substrate, etc.), or other suitable substrate. In the present embodiment, the substrate 10 is exemplified by a silicon substrate, but is not limited thereto.

Next, as shown in fig. 1B, a first sacrificial layer 12 is formed on the substrate 10, and a plurality of first through holes 121, a plurality of bump stop through holes 122 and rail grooves 123 are defined on the first sacrificial layer 12. In an embodiment, the rail slot 123 is formed, for example, on the periphery of the first sacrificial layer 12, the plurality of first through holes 121 are formed, for example, around the middle region of the first sacrificial layer 12, and the periphery of each first through hole 121 is surrounded with, for example, a bump stop through hole 122. Specifically, the first sacrificial layer 12 is formed on the substrate 10 by using chemical vapor deposition or other suitable methods, and the first through holes 121, the plurality of bump stopper through holes 122, and the rail grooves 123 may be formed in the first sacrificial layer 12 by photolithography, etching, and the like. The material of the first sacrificial layer 12 is preferably silicon dioxide, so as to form insulation with the diaphragm 14 (shown in fig. 1C) formed later, and has a high etching selectivity during the structure release process, so as to avoid damage to the diaphragm 14 caused by chemical solution during the structure release. The material of the first sacrificial layer 12 is not limited thereto, but may include, for example, silicon nitride, a stack of silicon oxide and silicon nitride, or other suitable materials, and may be specifically selected as desired, which is not limited thereto.

Next, as shown in fig. 1C, a diaphragm 14 is formed on the first sacrificial layer 12. In an embodiment, the diaphragm 14 includes a main deformation region 14a and a non-main deformation region 14b, wherein the non-main deformation region 14b surrounds the main deformation region 14a, and the positions of the first through holes 121 and the bump stop through holes 122 defined on the first sacrificial layer 12 correspond to the peripheral and peripheral regions of the main deformation region 14 a. Specifically, the diaphragm 14 is formed by physical vapor deposition or other suitable method, wherein a portion of the diaphragm 14 is filled into the bump stop through hole 122 (shown in fig. 1B) to form the bump stop 141 on the bottom surface of the main deformation region 14a, and a portion of the diaphragm 14 is filled into the partial rail groove 123 to form the first protection rail 142 on the periphery of the non-main deformation region 14B. A plurality of diaphragm through holes 143 are formed in the peripheral area of the main deformation region 14a of the diaphragm 14 and correspond to the plurality of first through holes 121, and specifically, the diaphragm through holes 143 are formed by patterning the diaphragm 14 by photolithography, etching, and other processes. The material of the diaphragm 14, which is used as the vibrating electrode of the mems microphone, may include a polysilicon layer, a metal layer, a laminate of an insulating layer and a polysilicon layer, a laminate of an insulating layer and a metal layer, or other elastic metals. In an embodiment, before forming the diaphragm 14, an extremely thin silicon dioxide layer 13 may be formed on the surface of the substrate 10 exposed by the first through holes 121, the plurality of bump stopper through holes 122 and the rail grooves 123, so that the bump stopper 141 is not directly contacted to the surface of the substrate 10.

Next, as shown in fig. 1D, a second sacrificial layer 16 is formed on the diaphragm 14, and a plurality of second through holes 161 and a plurality of predefined through holes 162 are defined on the second sacrificial layer 16. The plurality of second through holes 161 correspond to the plurality of diaphragm through holes 143, respectively, and the plurality of predefined through holes 162 correspond to the main deformation region 14a, for example, to the middle region of the main deformation region 14 a. Specifically, in one embodiment, the second sacrificial layer 16 is formed by chemical vapor deposition, physical vapor deposition, or other suitable method, and the material of the second sacrificial layer 16 may include silicon dioxide or other suitable materials, and the material of the second sacrificial layer 16 may be the same as or different from the material of the first sacrificial layer 12, which is not limited herein. However, as a preferred aspect, the material of the second sacrificial layer 16 and the material of the diaphragm 14 have a high etching selectivity, so as to avoid damage to the diaphragm 14 during subsequent etching. In yet another embodiment, the second via 161 and the predefined via 162 may be formed in the second sacrificial layer 16 by photolithography, etching, and the like. Also, in an embodiment, the second sacrificial layer 16 also defines a rail slot 163 at the periphery of the second sacrificial layer 16, the rail slot 163 corresponds to the rail slot 123 at the periphery of the first sacrificial layer 12, and the first protection rail 142 is exposed through the rail slot 163.

Next, as shown in fig. 1E, a third sacrificial layer 18 is formed on the second sacrificial layer 16, a plurality of third through holes 181 are defined on the third sacrificial layer 18 and correspond to the plurality of second through holes 161, and a portion of the third sacrificial layer 18 is deposited on the plurality of predefined through holes 162 (shown in fig. 1D) to form a plurality of anti-sticking block through holes 182 on the third sacrificial layer 18, wherein a portion of the third sacrificial layer 18' covers the sidewalls of the first through holes 121, the diaphragm through holes 143 and the second through holes 161. Specifically, in one embodiment, the third sacrificial layer 18 is formed by using chemical vapor deposition, physical vapor deposition, or other suitable method, wherein the pattern of the plurality of predefined vias 162 of the second sacrificial layer 16 is transferred to the anti-stick block via 182 formed by the third sacrificial layer 18, and the aperture of the anti-stick block via 182 is smaller than the aperture of the predefined via 162. The material of the third sacrificial layer 18 may include silicon dioxide or other suitable materials, and the material of the third sacrificial layer 18 may be the same as or different from the material of the second sacrificial layer, which is not limited herein. However, as a preferred aspect, the material of the third sacrificial layer 18 and the material of the diaphragm 14 have a high etching selectivity, so as to avoid damage to the diaphragm 14 during subsequent etching. Also, in an embodiment, the third sacrificial layer 18 also defines a rail slot 183 at the periphery of the third sacrificial layer 18, the rail slot 183 corresponds to the rail slot 163 at the periphery of the second sacrificial layer 16, and the first protection rail 142 is exposed through the rail slot 183.

Referring to fig. 1E, an anti-adhesion layer 20 is formed on a portion of the third sacrificial layer 18, and a portion of the anti-adhesion layer 20 corresponding to the main deformation region 14a is filled with a plurality of anti-adhesion block through holes 182 to form a plurality of anti-adhesion blocks 201. Specifically, the anti-adhesion layer 20 is deposited by chemical vapor deposition, physical vapor deposition or other suitable method to cover the portion of the third sacrificial layer 18 corresponding to the main deformation region 14a, and the anti-adhesion layer 20 is filled into the anti-adhesion stop through hole 182, and the material of the anti-adhesion layer 20 is, for example, silicon nitride. Next, as shown in fig. 1F, a back plate electrode 22 is formed on the adhesion preventing layer 20, and the back plate electrode 22 corresponds to the main deformation region 14a.

Thereafter, as shown in fig. 1G, a backplate body 24, a plurality of support structures 26 and a second protection fence 28 are formed, wherein the backplate body 24 is disposed on the backplate electrode 22 and extends, for example, to above the third through holes 181 (shown in fig. 1F), and the backplate body 24 and the backplate electrode 22 form a backplate structure 30 corresponding to the main deformation region 14a. The support structure 26 is connected to the back plate main body 24, and the support structure 26 is disposed through the third through hole 181, the second through hole 161 (shown in fig. 1F), the diaphragm through hole 143 (shown in fig. 1F), and the first through hole 121 (shown in fig. 1F), and the second protection rail 28 is disposed in the communicating rail grooves 183, 163, 123 (shown in fig. 1F) and covers a portion of the first protection rail 142, and then, a plurality of sound holes 32 are formed in the back plate structure 30, and as shown in fig. 1G, a portion of the third sacrificial layer 18 that is not covered by the back plate structure 30 and corresponds to the non-main deformation region 14b is also removed.

Afterwards, the main electrical structure of the mems microphone is fabricated, for example, a conductive contact electrode conductive layer is defined by a common process, and the description thereof is omitted. Next, a polishing process is performed on the back surface of the substrate 10 away from the first sacrificial layer 12, as shown in fig. 1H, to obtain a thinned substrate 10'. In one embodiment, the thinned substrate 10' may be formed using chemical mechanical polishing or other suitable process.

Thereafter, as shown in fig. 1I, a shutter mask 34 and a cavity mask 36 are provided on the back surface of the thinned substrate 10 'away from the first sacrificial layer 12 so as to pattern the back surface of the thinned substrate 10'. As shown in fig. 1J, after forming the cavity 38 and the plurality of gate structures 40 of the thinned substrate 10' by patterning and etching processes, the gate mask 34 (shown in fig. 1I) and the cavity mask 36 (shown in fig. 1I) are removed. The cavity 38 extends through the thinned substrate 10', the plurality of gate structures 40 extend from an inner wall 381 of the cavity 38 toward the center of the cavity 38, in an embodiment, the plurality of gate structures 40 extend toward the center and are distributed at the end corresponding to the periphery of the main deformation region 14a of the diaphragm 14, and the plurality of gate structures 40 respectively correspond to the plurality of support structures 26, so that the effect of stabilizing the support structures 26 is provided by the gate structures 40, and the overall mechanical structure is more stable. The portion of the diaphragm 14 originally filled in the bump stopper through hole 122 (shown in fig. 1B) of the first sacrificial layer 12 faces the gate structure as the bump stopper 141.

Specifically, a deep reactive ion etch or other suitable process is used to form the cavity 38 in the substrate 10', where the cavity 38 extends through the substrate 10' in a vertical direction, wherein different combinations of the shutter masks 34 may be used to form the height differences when patterning the back surface of the substrate 10' to form the shutter structure 40 on the inner wall 381 of the cavity 38. In one embodiment, during the patterning and etching process, a portion of the first sacrificial layer 12 (shown in FIG. 1I) is removed, leaving a portion of the first sacrificial layer 12' adjacent to the diaphragm 14 side.

Afterwards, the remaining portions of the first sacrificial layer 12', the second sacrificial layer 16 and the remaining third sacrificial layer 18 are removed, as shown in fig. 1K, so that the main deformation region 14a of the diaphragm 14 and the anti-adhesion layer 20 are directly faced, and the anti-adhesion stop 201 originally filled in the anti-adhesion stop through hole 182 (shown in fig. 1D) faces the main deformation region 14a, and an air gap G exists between the main deformation region 14a and the backplate electrode 22, where the air gap G is located, and can be used as a structural operation region of the mems capacitive microphone 100. The first through hole 121 (shown in fig. 1E), the diaphragm through hole 143 (shown in fig. 1E), and a portion of the third sacrificial layer 18' (shown in fig. 1J) covered by the sidewalls of the second through hole 161 (shown in fig. 1E) are removed together, so that a gap S exists between the support structure 26 and the inner wall of the diaphragm through hole 143.

Fig. 1K is a schematic cross-sectional view of a mems condenser microphone according to an embodiment of the invention, and fig. 2 is a schematic top view of the mems condenser microphone according to an embodiment of the invention. As shown in fig. 1K and 2, the microelectromechanical condenser microphone 100 mainly includes a substrate (i.e., thinned substrate 10'), a diaphragm 14, a backplate structure 30, a support structure 26, and a second protective rail 28. The substrate 10 'has a cavity 38 and a plurality of gate structures 40, the cavity 38 penetrates the substrate 10', the plurality of gate structures 40 extend from an inner wall 381 of the cavity 38 towards the center of the cavity 38, the diaphragm 14 is vibratingly disposed on the substrate 10', the diaphragm 14 includes a main deformation region 14a and a non-main deformation region 14b, the non-main deformation region 14b surrounds the main deformation region 14a, wherein the main deformation region 14a has a bottom 144 facing the cavity 38, a plurality of bump stops 141 are formed on the bottom 144, a first protection fence 142 is formed on a periphery of the non-main deformation region 14b and is fixed on the substrate 10', and in one embodiment, a plurality of diaphragm through holes 143 are formed in a peripheral region of the main deformation region 14a of the diaphragm 14.

Continuing the above description, the back plate structure 30 is disposed on the main deformation region 14a corresponding to the main deformation region 14a, and the main deformation region 14a is located between the substrate 10' and the back plate structure 30, and the back plate structure 30 is formed with a plurality of sound holes 32, and the plurality of support structures 26 are disposed on the back plate structure 30, penetrating through the periphery of the main deformation region 14a and respectively abutting against the plurality of gate structures 40, wherein the support structures 26 are adapted to penetrate through the diaphragm through holes 143, and gaps S exist between the support structures 26 and the inner walls of the diaphragm through holes 143. In an embodiment, the bump stop 141 formed on the bottom surface 144 of the main deformation region 14a of the diaphragm 14 is adapted to be disposed around the periphery of the support structure 26. In an embodiment, the backplate structure 30 includes a backplate body 24 and backplate electrodes 22, the diaphragm 14 is a vibrating electrode, the main deformation region 14a of the diaphragm 14 faces the backplate electrodes 22, and an air gap G exists between the main deformation region 14a and the backplate electrodes 22. The backplate structure 30 includes a plurality of anti-adhesion stoppers 201 connected to the backplate electrode 22 and protruding toward the main deformation region 14a.

Fig. 3 is a schematic top view of a cavity and silicon gate structure according to an embodiment of the present invention, and as shown in fig. 3, a plurality of gate structures 40 extend from an inner wall 381 of the cavity 38 toward the center of the cavity 38 in a centripetal shape. The shape of the shutter structure 120 may be one of an elongated shape, a circular shape, a ring shape, an oval shape, a honeycomb shape, a square shape, a triangle shape, a polygon shape, or a combination thereof.

Fig. 4A and fig. 4B are schematic top views of a microelectromechanical condenser microphone according to another embodiment of the invention, where, as shown in fig. 4A and fig. 4B, the back plate structure 30 further includes a reinforcing frame 42, and a plurality of support structures 26 are connected together in a ring, as shown in fig. 4A, the reinforcing frame 42 has a single ring structure, and as shown in fig. 4B, the reinforcing frame 42A has a double ring structure. By the design of the reinforcing frame 42/42A, the reliability of the back plate structure can be increased.

Continuing with the above description, as shown in fig. 1K, the second protection fence 28 is disposed on the substrate 10' and completely covers the first protection fence 142, but not limited thereto, fig. 5 is a schematic partial cross-sectional view of the first protection fence and the second protection fence according to another embodiment of the present invention, and as shown in fig. 5, the second protection fence 28 does not completely cover the first protection fence 142, wherein, for example, the second protection fence 28 only covers a part of the lateral portion 142a of the first protection fence 142, but does not cover the longitudinal portion 142b of the first protection fence 142, so as to increase the deformation amount of the diaphragm 14.

In the mems condenser microphone according to the embodiment of the present invention, the optimal sensing area between the diaphragm and the backplate is set according to the deformation curve of the diaphragm, and a backplate structure (hereinafter referred to as a "pavilion backplate") similar to a pavilion is set only in the optimal capacitive coupling area corresponding to the diaphragm and the backplate structure. In other words, by means of the supporting structure corresponding to the flashboard structure and supporting the periphery of the pavilion type backboard, the pavilion type backboard can further improve the rigidity of the backboard due to the inward movement of the supporting position besides the reduced area, namely, the reduced pavilion type backboard has higher rigidity than the traditional backboard under the same backboard thickness, so that the pavilion type backboard is less prone to generating synchronous deformation with the vibrating diaphragm under the action of sound pressure to influence the performance.

Continuing with the above description, since the pavilion-type backplate is only disposed in the center of the cavity of the substrate, and no backplate structure is disposed in the region other than the optimal capacitive coupling, no additional air impedance is generated, and therefore signal to noise ratio degradation of the diaphragm is not affected. Compared with the traditional method that the signal to noise ratio can be improved only by one way by increasing the chip area, the micro-electromechanical capacitive microphone of the embodiment of the invention uses the reduced pavilion type backboard design, and removes the traditional backboard using area outside the optimal capacitive coupling and area, so that the signal to noise ratio can be improved without increasing the area of a single chip, and the chip output of a single wafer can be improved.

The present invention is not limited to the preferred embodiments, and the present invention is described above in any way, but is not limited to the preferred embodiments, and any person skilled in the art will appreciate that the present invention is not limited to the embodiments described above, while the above-described methods and techniques may be utilized to make some changes or modifications to equivalent embodiments, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical principles of the present invention will still fall within the scope of the technical solutions of the present invention.

Claims (12)

1. A micro-electromechanical capacitive microphone, characterized by comprising the following steps:

A substrate having a cavity and a plurality of shutter structures, the cavity extending through the substrate, the shutter structures extending from an inner wall of the cavity toward a center of the cavity;

The vibrating diaphragm is arranged on the substrate in a vibrating way and comprises a main deformation area and a non-main deformation area, the non-main deformation area surrounds the main deformation area, the main deformation area is provided with a bottom surface facing the cavity, a plurality of anti-collision stops are formed on the bottom surface, and a first protection fence is formed on the periphery of the non-main deformation area and fixed on the substrate;

The back plate structure is arranged on the main deformation area corresponding to the main deformation area, the main deformation area is positioned between the substrate and the back plate structure, and a plurality of sound holes are formed on the back plate structure;

A plurality of support structures arranged on the back plate structure, penetrating the periphery of the main deformation area and respectively propping against the flashboard structure, and

And a second protective fence arranged on the substrate and covering at least part of the first protective fence.

2. The microelectromechanical condenser microphone of claim 1, wherein the bump stop is adapted to be disposed around the perimeter of each of the support structures.

3. The microelectromechanical condenser microphone of claim 1, wherein the backplate structure comprises a backplate body and a backplate electrode, the main deformation region of the diaphragm facing the backplate electrode with an air gap therebetween.

4. The mems microphone of claim 3, wherein the backplate structure further comprises a plurality of anti-adhesion stops connected to the backplate electrode and protruding toward the main deformation region.

5. The mems condenser microphone of claim 1, wherein the back plate structure further comprises a reinforcing frame that connects the support structures together in a ring.

6. The microelectromechanical condenser microphone of claim 1, wherein the paddle structure is uniformly distributed radially on the inner wall of the cavity.

7. The microelectromechanical condenser microphone of claim 1, wherein the shape of the paddle structure is selected from one of elongated, circular, annular, elliptical, honeycomb, square, triangular, or a combination thereof.

8. The microelectromechanical condenser microphone of claim 1, wherein the diaphragm has a plurality of diaphragm through holes formed therein for the support structures to pass therethrough, respectively.

9. A method for manufacturing a microelectromechanical condenser microphone, comprising:

Providing a substrate;

Forming a first sacrificial layer on the substrate, wherein a plurality of first through holes, a plurality of anti-collision stop block through holes and a fence slot are defined on the first sacrificial layer;

Forming a vibrating diaphragm on the first sacrificial layer, wherein the vibrating diaphragm comprises a main deformation area and a non-main deformation area, the non-main deformation area surrounds the main deformation area, the positions of the first through holes and the anti-collision stop through holes correspond to the peripheral area of the main deformation area, part of the vibrating diaphragm is filled into the anti-collision stop through holes so as to be suitable for forming a plurality of anti-collision stops on the bottom surface of the main deformation area, part of the vibrating diaphragm is filled into part of the rail grooves so as to be suitable for forming a first protection rail on the periphery of the non-main deformation area, and a plurality of vibrating diaphragm through holes are formed in the peripheral area of the main deformation area and correspond to the first through holes respectively;

Forming a second sacrificial layer on the vibrating diaphragm, wherein a plurality of second through holes and a plurality of predefined through holes are defined on the second sacrificial layer, the second through holes respectively correspond to the vibrating diaphragm through holes, and the positions of the predefined through holes correspond to the main deformation area;

Forming a third sacrificial layer on the second sacrificial layer, wherein a plurality of third through holes are defined on the third sacrificial layer and correspond to the second through holes respectively, and a part of the third sacrificial layer is deposited on the predefined through holes so as to be suitable for forming a plurality of anti-sticking block through holes on the third sacrificial layer;

Forming an anti-adhesion layer on part of the third sacrificial layer, wherein the anti-adhesion layer corresponds to the main deformation area, and part of the anti-adhesion layer is filled into the anti-adhesion stop block through hole so as to be suitable for forming a plurality of anti-adhesion stop blocks;

forming a backboard electrode on the anti-adhesion layer;

Forming a backboard main body, a plurality of supporting structures and a second protection fence, wherein the backboard main body is arranged on the backboard electrode, the backboard main body and the backboard electrode form a backboard structure corresponding to the main deformation area, each supporting structure penetrates through each third through hole, each second through hole, each vibrating diaphragm through hole and each first through hole, and the second protection fence is arranged in the fence grooving and covers at least part of the first protection fence;

Forming a plurality of sound holes in the back plate structure;

forming a cavity and a plurality of gate structures on the substrate, wherein the cavity penetrates through the substrate, the gate structures extend from the inner wall of the cavity towards the center of the cavity, and the gate structures respectively correspond to the supporting structures, and

And removing the first sacrificial layer, the second sacrificial layer and the third sacrificial layer.

10. The method of claim 9, wherein a polishing process is performed on a back surface of the substrate away from the first sacrificial layer before the cavity and the gate structure are formed on the substrate, so as to thin the substrate.

11. The method of claim 9, wherein the first sacrificial layer, the second sacrificial layer, and the third sacrificial layer are made of silicon oxide, silicon nitride, or a combination thereof.

12. The method of claim 9, wherein the diaphragm is a polysilicon layer, a metal layer, a lamination of an insulating layer and a polysilicon layer, or a lamination of an insulating layer and a metal layer.