阅读说明：本技术 Mems麦克风及其制备方法 (MEMS microphone and preparation method thereof ) 是由 吕婷 于 2021-09-23 设计创作，主要内容包括：本发明提供一种MEMS麦克风及其制备方法。麦克风包括基底、背极和背板材料层,基底中形成有空腔；振膜架设于基底上,振膜中形成有褶皱结构及泄气孔；背极位于振膜上方,且与振膜具有间距,背极中形成有多个声孔；背板材料层位于背极上,且向外延伸至基底的表面,背板材料层中形成有多个开孔、若干背极阻挡块和支撑柱,开孔一一对应显露出声孔,支撑柱和背极阻挡块穿过背极并向下延伸,支撑柱与振膜相连接。本发明在振膜上设置褶皱结构的同时设置位于背极和振膜之间的支撑柱,可以确保MEMS麦克风在具有很高的检测灵敏度的同时避免振膜局部振幅过大,避免振膜破损以及和背极之间发生粘连,有助于提高MEMS麦克风的机械强度和性能。(The invention provides an MEMS microphone and a preparation method thereof. The microphone comprises a substrate, a back pole and a back plate material layer, wherein a cavity is formed in the substrate; the vibrating diaphragm is erected on the substrate, and a fold structure and an air leakage hole are formed in the vibrating diaphragm; the back electrode is positioned above the vibrating diaphragm and has a distance with the vibrating diaphragm, and a plurality of sound holes are formed in the back electrode; the back plate material layer is located on the back electrode and extends outwards to the surface of the substrate, a plurality of openings, a plurality of back electrode blocking blocks and supporting columns are formed in the back plate material layer, the sound holes are exposed in the openings in a one-to-one correspondence mode, the supporting columns and the back electrode blocking blocks penetrate through the back electrode and extend downwards, and the supporting columns are connected with the vibrating diaphragm. The support column is arranged between the back electrode and the vibrating diaphragm while the corrugated structure is arranged on the vibrating diaphragm, so that the MEMS microphone can be ensured to have high detection sensitivity, the local amplitude of the vibrating diaphragm is prevented from being too large, the vibrating diaphragm is prevented from being damaged and from being adhered to the back electrode, and the mechanical strength and the performance of the MEMS microphone are improved.)

1. A preparation method of an MEMS microphone is characterized by comprising the following steps:

providing a substrate, and forming a first sacrificial layer on the substrate;

carrying out graphical processing on the first sacrificial layer to form a first groove corresponding to the diaphragm;

forming a vibrating diaphragm material layer on the first sacrificial layer, wherein the vibrating diaphragm material layer fills the first groove to form a vibrating diaphragm, and the vibrating diaphragm comprises a folded structure and a support located on the outer side of the folded structure;

forming a gas release hole in the diaphragm, wherein the first sacrificial layer is exposed from the gas release hole;

forming a second sacrificial layer by adopting a conformal deposition method, wherein the second sacrificial layer covers the vibrating diaphragm and the air leakage hole, and the upper surface of the formed second sacrificial layer is provided with a concave-convex structure corresponding to the corrugated structure of the vibrating diaphragm;

grinding the second sacrificial layer to enable the upper surface of the second sacrificial layer to be flush;

etching the second sacrificial layer to form a second groove corresponding to the back electrode blocking block, wherein the depth of the second groove corresponding to the back electrode blocking block is smaller than the height of the second sacrificial layer;

forming a back electrode material layer on the surface of the second sacrificial layer, wherein the back electrode material layer covers the second sacrificial layer and fills the second groove;

etching the back pole material layer to form a back pole, wherein a plurality of sound holes are formed in the back pole, the second grooves corresponding to the back pole blocking blocks are exposed in the back pole, and the second sacrificial layers are exposed out of the plurality of sound holes;

forming a back plate material layer, wherein the back plate material layer covers the back pole material layer and fills the sound holes and the second grooves;

removing the back plate material layer correspondingly positioned in the sound hole until the second sacrificial layer is exposed in the sound hole, wherein the back plate material filled in the second groove corresponding to the back pole blocking block forms the back pole blocking block, and the back pole blocking block penetrates through the back pole and extends downwards;

forming a cavity in the substrate, the cavity penetrating through the substrate;

and etching the first sacrificial layer and the second sacrificial layer to release the diaphragm and the back electrode.

2. The method of claim 1, further comprising thinning the substrate before forming the cavity through the substrate, and then forming the cavity in the thinned substrate.

3. The method of claim 1, wherein the first sacrificial layer and the second sacrificial layer are made of silicon oxide, and the thickness of the second sacrificial layer is greater than that of the first sacrificial layer.

4. The method for preparing the MEMS microphone according to claim 1, wherein the diaphragm and the back electrode are made of polysilicon, the plurality of air release holes and the plurality of supports are arranged between the corrugated structure and the supports.

5. The method of claim 1, wherein the step of forming a cutting channel on the periphery of the diaphragm while forming the air-release hole in the diaphragm, the cutting channel exposing the first sacrificial layer, and then the step of etching the corresponding material layers to expose the cutting channel during the processing of the second sacrificial layer, the back electrode material layer, and the back plate material layer.

6. The method of claim 1, wherein the material of the backplate material layer comprises silicon nitride, and the backplate material layer extends outward to the surface of the substrate and has a distance from the diaphragm.

7. The method for preparing the MEMS microphone according to any one of claims 1 to 6, wherein a second groove corresponding to the supporting pillar is simultaneously formed in the second sacrificial layer during the process of etching the second groove corresponding to the back electrode barrier, wherein the second groove corresponding to the supporting pillar penetrates through the second sacrificial layer, the supporting pillar is formed by a back plate material subsequently filled in the second groove corresponding to the supporting pillar, the supporting pillar penetrates through the back electrode and extends downward to be connected with the diaphragm, and the supporting pillar is located above the cavity.

8. A MEMS microphone, comprising:

a substrate having a cavity formed therein that extends through the substrate;

the vibrating diaphragm is erected on the substrate through a support, and a corrugated structure and an air leakage hole penetrating through the vibrating diaphragm are formed in the vibrating diaphragm;

the back electrode is positioned above the vibrating diaphragm and has a distance with the vibrating diaphragm, and a plurality of sound holes are formed in the back electrode;

the back plate material layer is positioned on the back electrode and extends outwards to the surface of the substrate, a plurality of openings, a plurality of back electrode blocking blocks and supporting columns are formed in the back plate material layer, the sound holes are exposed in the openings in a one-to-one correspondence mode, the supporting columns and the back electrode blocking blocks penetrate through the back electrode and extend downwards, and the supporting columns are connected with the vibrating diaphragm.

9. The MEMS microphone of claim 8, wherein the support post comprises any one of a circular post and a polygonal post.

10. The MEMS microphone of claim 8, wherein the back pole barrier has a height of 1/4-3/4 of the back pole-to-diaphragm spacing, wherein the back pole barrier is not disposed above the corrugated structure; the fold structure is an annular structure and is wound on the periphery of the support column.

Technical Field

The invention relates to the technical field of micro electro mechanical systems, in particular to an MEMS microphone and a preparation method thereof.

Background

With the rapid development of consumer electronics, the microphone industry is also developing vigorously. The microphone is widely applied to the fields of consumer electronics, smart home and the like, and all devices with sound control functions need the microphone. In recent years, conventional electret condenser microphones have been replaced by MEMS microphones because of the relatively cumbersome matching work.

The MEMS microphone comprises a diaphragm capable of vibrating up and down and a fixed back plate, the back plate has excellent rigidity and is etched with a sound hole, air circulation is allowed without deviation, the diaphragm can bend along with sound waves to cause the diaphragm to move relative to the back plate to generate certain capacitance change, and the weak capacitance change is amplified and converted into an electric signal to be output through an ASIC chip connected with the MEMS microphone.

In the existing MEMS microphone structure, a corrugated structure is usually disposed on a diaphragm 21, which is beneficial to increase the amplitude of the diaphragm in the same area, but a groove of the corrugated structure may cause the back electrode 22 to grow in shape during the preparation process, which may cause stress concentration in an area a indicated by a dashed box shown in fig. 1, and may cause crack damage. In addition, the vibration amplitude of the diaphragm is too large or the attraction between the diaphragm and the back electrode is easy to occur when conductive particles exist between the back electrodes of the diaphragm.

Disclosure of Invention

In view of the above drawbacks of the prior art, an object of the present invention is to provide an MEMS microphone and a manufacturing method thereof, for solving the problems that when the MEMS microphone in the prior art is provided with a corrugated structure, a part of stress corresponding to the corrugated structure of a diaphragm is concentrated due to conformal growth of the back electrode in the manufacturing process, so that cracks occur in the back electrode, and the diaphragm and the back electrode are easy to be attracted when the amplitude of the diaphragm is too large or conductive particles exist between the back electrodes of the diaphragm.

To achieve the above and other related objects, the present invention provides a method for manufacturing a MEMS microphone, comprising the steps of:

providing a substrate, and forming a first sacrificial layer on the substrate;

carrying out graphical processing on the first sacrificial layer to form a first groove corresponding to the diaphragm;

forming a vibrating diaphragm material layer on the first sacrificial layer, wherein the vibrating diaphragm material layer fills the first groove to form a vibrating diaphragm, and the vibrating diaphragm comprises a folded structure and a support located on the outer side of the folded structure;

forming a gas release hole in the diaphragm, wherein the first sacrificial layer is exposed from the gas release hole;

forming a second sacrificial layer by adopting a conformal deposition method, wherein the second sacrificial layer covers the vibrating diaphragm and the air leakage hole, and the upper surface of the formed second sacrificial layer is provided with a concave-convex structure corresponding to the corrugated structure of the vibrating diaphragm;

grinding the second sacrificial layer to enable the upper surface of the second sacrificial layer to be flush;

etching the second sacrificial layer to form a second groove corresponding to the back electrode blocking block, wherein the depth of the second groove corresponding to the back electrode blocking block is smaller than the height of the second sacrificial layer;

forming a back electrode material layer on the surface of the second sacrificial layer, wherein the back electrode material layer covers the second sacrificial layer and fills the second groove;

etching the back pole material layer to form a back pole, wherein a plurality of sound holes are formed in the back pole, the second grooves corresponding to the back pole blocking blocks are exposed in the back pole, and the second sacrificial layers are exposed out of the plurality of sound holes;

forming a back plate material layer, wherein the back plate material layer covers the back pole material layer and fills the sound holes and the second grooves;

removing the back plate material layer correspondingly positioned in the sound hole until the second sacrificial layer is exposed in the sound hole, wherein the back plate material filled in the second groove corresponding to the back pole blocking block forms the back pole blocking block, and the back pole blocking block penetrates through the back pole and extends downwards;

forming a cavity in the substrate, the cavity penetrating through the substrate;

and etching the first sacrificial layer and the second sacrificial layer to release the diaphragm and the back electrode.

Optionally, before forming the cavity penetrating through the substrate in the substrate, the method further includes a step of thinning the substrate, and then forming the cavity in the thinned substrate.

Optionally, the material of the first sacrificial layer and the material of the second sacrificial layer both include silicon oxide.

Optionally, the thickness of the second sacrificial layer is greater than the thickness of the first sacrificial layer.

Optionally, the material of the diaphragm and the back electrode includes polysilicon.

Optionally, the air release holes and the bracket are multiple, and the air release holes are located between the folded structure and the bracket.

Optionally, the method further includes forming a cutting street on the periphery of the diaphragm while forming the air release hole in the diaphragm, where the cutting street exposes the first sacrificial layer, and then etching the corresponding material layers to expose the cutting street in the process of processing the second sacrificial layer, the back electrode material layer, and the back plate material layer.

Optionally, the material of the backplate material layer includes silicon nitride, and the backplate material layer extends outward to the surface of the substrate and has a distance from the diaphragm.

Optionally, a second groove corresponding to the supporting pillar is further formed in the second sacrificial layer in a synchronous manner in the process of etching the second groove corresponding to the back electrode blocking block, wherein the second groove corresponding to the supporting pillar penetrates through the second sacrificial layer, the supporting pillar is formed by a back plate material subsequently filled in the second groove corresponding to the supporting pillar, the supporting pillar penetrates through the back electrode and extends downwards to be connected with the diaphragm, and the supporting pillar is located above the cavity.

The present invention also provides a MEMS microphone, comprising:

a substrate having a cavity formed therein that extends through the substrate;

the vibrating diaphragm is erected on the substrate through a support, and a corrugated structure and an air leakage hole penetrating through the vibrating diaphragm are formed in the vibrating diaphragm;

the back electrode is positioned above the vibrating diaphragm and has a distance with the vibrating diaphragm, and a plurality of sound holes are formed in the back electrode;

the back plate material layer is positioned on the back electrode and extends outwards to the surface of the substrate, a plurality of openings, a plurality of back electrode blocking blocks and supporting columns are formed in the back plate material layer, the sound holes are exposed in the openings in a one-to-one correspondence mode, the supporting columns and the back electrode blocking blocks penetrate through the back electrode and extend downwards, and the supporting columns are connected with the vibrating diaphragm.

Optionally, the support column includes any one of a circular column and a polygonal column.

Optionally, the height of the back pole barrier is 1/4-3/4 of the distance between the back pole and the diaphragm.

Optionally, the back pole barrier is not disposed above the corrugated structure.

Optionally, the corrugated structure is an annular structure and is wound around the periphery of the support column.

As described above, the MEMS microphone and the method for manufacturing the same according to the present invention have the following advantageous effects: according to the invention, the second sacrificial layer is formed through conformal deposition, then the second sacrificial layer is ground, the stress of the second sacrificial layer can be effectively released through grinding, and meanwhile, the upper surface of the second sacrificial layer is a horizontal plane, so that adverse effects on subsequent processes, such as generation of cracks on a back electrode caused by overlarge local stress of a subsequent back electrode material layer, are avoided. Set up the support column that is located between back of the body utmost point and vibrating diaphragm through setting up fold structure on the vibrating diaphragm, can ensure that MEMS microphone avoids the local amplitude of vibrating diaphragm too big when having very high detectivity, avoid the vibrating diaphragm damage and with take place the adhesion between the back of the body utmost point, help improving MEMS microphone's mechanical strength and performance.

Drawings

Fig. 1 shows an exemplary structure diagram of a MEMS microphone in the prior art.

Fig. 2 to 16 are schematic cross-sectional structures of MEMS microphones in various steps of the manufacturing process.

Description of the element reference numerals

11 substrate

111 hollow cavity

12 first sacrificial layer

121, 121a, 121b, 121c first grooves

13 diaphragm

131 fold structure

132 bracket

133 air escape hole

13a layer of diaphragm material

14 second sacrificial layer

141, 141a, 141b second recess

142 concave-convex structure

15 support column

16 back pole block

17 back pole

171 sound hole

17a back electrode material layer

18 layer of backing material

181 opening hole

19 cutting path

21 diaphragm

22 backboard

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated. In order to keep the drawings as concise as possible, not all features of a single figure may be labeled in their entirety.

In order to improve the detection accuracy of the MEMS microphone, a through hole or a corrugated structure is usually disposed on the diaphragm to improve the response of the diaphragm to external excitation, but this may cause damage to the diaphragm or attraction with the back electrode due to excessive local amplitude. Meanwhile, local stress of the MEMS microphone may be too concentrated to affect the performance of the device during the manufacturing process. Therefore, the inventor has long studied and proposed an improvement scheme which helps to improve the mechanical strength of the microphone while maintaining the diaphragm corrugation structure.

Specifically, the invention provides a preparation method of an MEMS microphone, which comprises the following steps:

providing a substrate 11, and forming a first sacrificial layer 12 on the substrate 11; the substrate 11 is preferably a substrate 11 made of a semiconductor material, including but not limited to silicon, silicon germanium, silicon carbide, SOI or sapphire, the first sacrificial layer 12 is preferably but not limited to a silicon oxide layer, the formation method includes but not limited to an oxidation method and a vapor deposition method, and the structure obtained after the step is as shown in fig. 2;

patterning the first sacrificial layer 12 to form a first groove 121 corresponding to the diaphragm 12; the step may specifically include forming a first groove 121a corresponding to the corrugated structure of the diaphragm 12 by using a photolithography and etching process, and forming a first groove 121b corresponding to the diaphragm stop block in this step, that is, the first grooves 121a and 121b corresponding to the stop block and the corrugated structure may have the same depth, and the obtained structure is as shown in fig. 3, and then continuing to etch the first sacrificial layer 12 by using photolithography and etching to obtain a first groove 121c corresponding to the bracket 132 and penetrating through the first sacrificial layer 12, and the obtained structure is as shown in fig. 4;

forming a diaphragm material layer 12a on the first sacrificial layer 12, wherein the diaphragm material layer 12a fills the first groove 121 to form the diaphragm 12, and the diaphragm 12 includes a corrugated structure 131 and a bracket 132 located outside (a side away from the center is defined as an outer side) the corrugated structure 131; the diaphragm material layer 12a is preferably a polysilicon layer, and the forming method preferably adopts conformal deposition processes such as atomic layer deposition, etc., that is, the deposited polysilicon layer is completely filled with the first groove 121 to form the diaphragm 12 including the corrugated structure 131, the barrier block and the bracket 132; the structure obtained after this step is shown in fig. 5;

forming a venting hole 133 in the diaphragm 12 by using an etching process, including but not limited to, exposing the first sacrificial layer 12 through the venting hole 133; in this step, a cutting channel 19 may be etched on the periphery of the diaphragm 12 synchronously or after this step, and the cutting channel 19 exposes the surface of the substrate 11; the structure obtained after this step is shown in fig. 6;

forming a second sacrificial layer 14 by adopting a conformal deposition process, wherein the second sacrificial layer 14 covers the diaphragm 12 and the air release hole 133; specifically, the second sacrificial layer 14 is preferably a silicon dioxide layer, and is preferably formed by a conformal deposition process such as atomic layer deposition, so that a concave-convex structure 142 corresponding to the corrugated structure 131 of the diaphragm 12 is formed on the upper surface of the second sacrificial layer 14, and the obtained structure is as shown in fig. 7, and the second sacrificial layer 14 is preferably thicker than the first sacrificial layer 12, so as to ensure that a cavity with a certain volume is formed between the subsequently formed back electrode 17 and the diaphragm 12; under the condition that the concave-convex structure 142 is correspondingly formed on the second sacrificial layer 14, then, polishing is performed, for example, a chemical mechanical polishing process may be used to planarize the second sacrificial layer 14, so as to remove the concave-convex structure 142 and make the upper surface of the second sacrificial layer 14 be a horizontal plane, and through chemical mechanical polishing, the stress of the second sacrificial layer 14 can be effectively released, and simultaneously, the upper surface thereof is a horizontal plane, thereby avoiding the adverse effects on the subsequent processes, such as cracks on the back electrode caused by excessive local stress of the subsequent back electrode material layer 17a, and the like, caused by excessive local stress of the second sacrificial layer 14; the structure obtained after grinding is shown in fig. 8;

etching a second groove 141 corresponding to the back pole stopper 16 in the second sacrificial layer 14 by using an etching process including, but not limited to, etching, and in this step, a second groove corresponding to the supporting pillar 15 may be simultaneously formed, wherein the second groove 141b corresponding to the supporting pillar 15 penetrates through the second sacrificial layer 14 until the diaphragm 12 is exposed, and a depth of the second groove 141a corresponding to the back pole stopper 16 is less than a height of the second sacrificial layer 14, for example, may be 1/4-3/4 of a thickness of the second sacrificial layer 14, and is preferably within 1/2; the resulting structure after this step is shown in FIG. 9; this step may be followed by continued etching to reveal the dicing streets 19, the resulting structure being as described in fig. 10;

forming a back electrode material layer 17a on the surface of the second sacrificial layer 14, wherein the back electrode material layer 17a covers the second sacrificial layer 14 and fills the second groove 141; the back electrode material layer 17a is preferably but not limited to a polysilicon layer, and the formation method includes but not limited to a vapor deposition method, and the structure obtained after this step is as shown in fig. 11;

etching the back pole material layer 17a to form a back pole 17, wherein a plurality of sound holes 171 are formed in the back pole 17, the second grooves 141 corresponding to the back pole blocking blocks 16 and the supporting pillars 15 are exposed in the back pole 17 (i.e. the back pole material layer 17a in the second grooves is removed), the second sacrificial layer 14 is exposed in the plurality of sound holes 171, and the back pole material on the scribe line 19 can be removed at the same time; the resulting structure after this step is shown in FIG. 12;

forming a back plate material layer 18, wherein the back plate material layer 18 covers the back electrode material layer 17a and fills the sound hole 171 and the second groove 141; the layer 18 of backplate material is preferably a layer of silicon nitride, and the formation method is preferably a vapor deposition method, which may extend to the surface of the substrate 11 but has a distance from the diaphragm 12; the resulting structure after this step is shown in FIG. 13;

removing the backplate material layer 18 correspondingly located in the sound holes 171 until the second sacrificial layer 14 is exposed in the sound holes 171 (which can also be described as forming a plurality of openings in the backplate material layer 18, the plurality of openings correspondingly expose the sound holes 171 one by one, or the openings in the backplate material layer 18 are communicated up and down, or the openings in the backplate material layer 18 can also be considered as a part of the sound holes 171), if a second groove corresponding to the support pillar is formed, in this step, the backplate material filled in the second groove corresponding to the support pillar 15 forms the support pillar 15 (i.e. the support pillar 15 and the backplate material layer 18 are integrally connected, or the support pillar 15 extends downward from the backplate material layer 18 to below the back pole 17, and the support pillar 15 can be contacted with the back pole 17), and the backplate material filled in the second groove corresponding to the back pole block 16 forms the back pole block 16, the back pole stop block 16 and the support columns 15 penetrate through the back pole 17 and extend downwards, and the support columns 15 are connected with the diaphragm 12; the back plate blocking blocks 16 are preferably multiple (but the back plate blocking blocks 16 are preferably not arranged above the corrugated structure to avoid collision of parts of the corresponding corrugated structure with the back plate blocking blocks 16 due to too large amplitude), and are uniformly distributed on two opposite sides of the supporting column 15, the corrugated structure is an annular structure and is wound on the periphery of the supporting column 15, the supporting column 15 can be a circular column or a polygonal column (such as a quadrangle, a pentagon, a hexagon and the like, and is preferably circular in terms of process and the like), and the back plate material layer 18 located at the position of the cutting street 19 can be synchronously etched in the etching process; the resulting structure after this step is shown in FIG. 14;

forming a cavity in the substrate 11, wherein the supporting pillar 15 is located above the cavity; specifically, the substrate 11 may be first subjected to back grinding and thinning, and then the cavity is formed in the thinned substrate 11 by using a dry etching process, so that the obtained structure is as shown in fig. 15;

the first sacrificial layer 12 and the second sacrificial layer 14 are preferably etched by wet etching to release the diaphragm 12 and the back electrode 17, and the resulting structure is shown in fig. 16, where it can be seen that the diaphragm 12 is erected on the substrate 11 through the bracket 132, the corrugated structure 131 is located above the cavity, the diaphragm 12 is spaced from the back-plate material layer 18, and the lower surface of the diaphragm 12 has a plurality of blocking blocks (not shown), so as to prevent the diaphragm 12 and the substrate 11 from being adhered to each other.

Illustratively, the plurality of air release holes 133 and the bracket 132 are provided, and the plurality of air release holes 133 are located between the corrugated structure 131 and the bracket 132.

The present invention also provides a MEMS microphone that can be prepared based on any of the methods described above, and thus the foregoing can be incorporated herein in its entirety. Specifically, as shown in fig. 16, the MEMS microphone includes:

a substrate 11, wherein a cavity penetrating through the substrate 11 is formed in the substrate 11;

the vibrating diaphragm 12 is erected on the substrate 11 through a bracket 132, a corrugated structure 131 and an air release hole 133 penetrating through the vibrating diaphragm 12 are formed in the vibrating diaphragm 12, and the corrugated structure 131 is preferably correspondingly located above the cavity;

a back electrode 17 located above the diaphragm 12 and spaced apart from the diaphragm 12, wherein a plurality of sound holes 171 are formed in the back electrode 17;

the back plate material layer 18 is located on the back pole 17 and extends outward to the surface of the substrate 11, a plurality of openings, a plurality of back pole blocking blocks 16 and supporting columns 15 are formed in the back plate material layer 18, the openings expose the sound holes 171 in a one-to-one correspondence, the supporting columns 15 and the back pole blocking blocks 16 penetrate through the back pole 17 and extend downward, and the supporting columns 15 are connected with the diaphragm 12. A plurality of auxiliary supporting columns (not shown) may be further formed on the backplate material layer, and are spaced from the supporting columns, and the auxiliary supporting columns also penetrate the back pole downward and extend downward, except that the height of the auxiliary supporting columns is smaller than that of the supporting columns and is not connected with the diaphragm. The provision of the auxiliary support posts contributes to further improving the mechanical strength of the MEMS microphone.

The support column 15 includes, by way of example, any one of a circular column and a polygonal column.

By way of example, the height of the back pole stopper 16 is 1/4-3/4 of the distance between the back pole 17 and the diaphragm 12, preferably within 1/2, and preferably, the back pole stopper 16 is not arranged above the corrugated structure 131.

By way of example, the corrugated structure 131 is an annular structure and is disposed around the periphery of the supporting column 15.

As an example, the diaphragm 12 and the back electrode 17 are preferably polysilicon layers, and the back plate material layer 18 is preferably a polysilicon layer.

As an example, the MEMS microphone further includes a dicing street 19 located at the periphery of the diaphragm 12.

The substrate may be any one of a silicon substrate, a germanium substrate, an SOI substrate, a germanium-silicon substrate, a silicon carbide substrate, and other semiconductor substrates.

For more description of the MEMS microphone, please refer to the foregoing, and further description is omitted for brevity.

In summary, the invention provides an MEMS microphone and a method for manufacturing the same. The MEMS microphone comprises a substrate, a back pole and a back plate material layer, wherein a cavity penetrating through the substrate is formed in the substrate; the vibrating diaphragm is erected on the substrate through a support, and a corrugated structure and an air leakage hole penetrating through the vibrating diaphragm are formed in the vibrating diaphragm; the back electrode is positioned above the vibrating diaphragm and has a distance with the vibrating diaphragm, and a plurality of sound holes are formed in the back electrode; the back plate material layer is located on the back electrode and extends outwards to the surface of the substrate, a plurality of openings, a plurality of back electrode blocking blocks and supporting columns are formed in the back plate material layer, the sound holes are exposed in the openings in a one-to-one correspondence mode, the supporting columns and the back electrode blocking blocks penetrate through the back electrode and extend downwards, and the supporting columns are connected with the vibrating diaphragm. According to the invention, the second sacrificial layer is formed through conformal deposition, and then the second sacrificial layer is ground, so that the stress of the second sacrificial layer can be effectively released, and meanwhile, the upper surface of the second sacrificial layer is a horizontal plane, thereby avoiding adverse effects on subsequent processes caused by cracks generated in the second sacrificial layer due to overlarge local stress, such as adverse effects caused by cracks generated in a back electrode due to overlarge local stress of a subsequent back electrode material layer. Set up the support column that is located between back of the body utmost point and vibrating diaphragm through setting up fold structure on the vibrating diaphragm, can ensure that MEMS microphone avoids the local amplitude of vibrating diaphragm too big when having very high detectivity, avoid the vibrating diaphragm damage and with take place the adhesion between the back of the body utmost point, help improving MEMS microphone's mechanical strength and performance. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.