Micro-electro-mechanical system transducer and method of manufacturing micro-electro-mechanical system transducer

Abstract

The invention provides a micro-electro-mechanical system transducer and a method for manufacturing the micro-electro-mechanical system transducer, and relates to the technical field of semiconductor devices. Wherein the MEMS transducer comprises: a first membrane, the first membrane comprising at least one first arched membrane unit; the second membrane is provided with at least one second arched membrane unit which is symmetrical to the first arched membrane unit; the two ends of the supporting column are fixedly connected with the first arched membrane unit and the second arched membrane unit respectively; the vacuum cavity is formed by the first arched membrane unit, the second arched membrane unit and the supporting columns in a surrounding mode. According to the invention, the sensitivity and the stability of the micro-electro-mechanical system transducer with the sealed double-membrane structure can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular, to a microelectromechanical system transducer and a method for manufacturing a microelectromechanical system transducer. Background Art

[0002] In the technical field of microelectromechanical systems (MEMS), the sealed dual membrane (SDM) technology has emerged as an innovative design solution in recent years. By constructing a cavity structure formed by a double-layer membrane and support columns connecting therebetween, a vacuum region is ingeniously created. This design significantly reduces the background noise of the sensor, opening up a new path for improving the sensor performance. At the core of the SDM structure, the stator structure located at the center of the double-layer membrane and the cavity region together form a variable parallel plate capacitor structure, realizing an efficient physical field coupling between the mechanical domain and the electrical domain, enabling this structure to be widely used as a transducer in various sensors, especially in precision devices such as MEMS microphones.

[0003] Although the SDM technology exhibits unique advantages, since the membrane is mechanically anchored by the support columns, this inevitably increases the equivalent thickness of the membrane, that is, the equivalent acoustic mass, thereby limiting the improvement of the sensor sensitivity. In addition, the pressure difference between the inside and outside of the membrane results in obvious stress concentration near the connecting columns, which not only affects the vibration characteristics of the membrane but also may pose a threat to the long-term stability and reliability of the sensor. More complicatedly, when the support columns pass through specific structures such as perforated plates, it will interfere with the distribution and size design of the perforations, thereby affecting the equivalent damping characteristics of the entire structure, which is also an important factor restricting the improvement of the SDM sensor sensitivity.

[0004] Therefore, how to effectively improve the sensitivity and stability of the microelectromechanical system transducer with a sealed dual membrane structure is a technical problem to be urgently solved. Summary of the Invention

[0005] Aiming at the above problems existing in the prior art, the present invention provides a microelectromechanical system transducer and a method for manufacturing a microelectromechanical system transducer to effectively improve the sensitivity and stability of the microelectromechanical system transducer with a sealed dual membrane structure.

[0006] The present invention provides a microelectromechanical system transducer, comprising: a first membrane, the first membrane including at least one first arched membrane unit; a second membrane, the second membrane having at least one second arched membrane unit symmetrically arranged with the first arched membrane unit; a support column, two ends of the support column being fixedly connected to the first arched membrane unit and the second arched membrane unit respectively; a vacuum cavity, formed jointly surrounded by the first arched membrane unit, the second arched membrane unit and the support column.

[0007] For a microelectromechanical system transducer provided by the present invention, the first membrane further includes a first planar membrane unit; the second membrane further includes a second planar membrane unit.

[0008] For a microelectromechanical system transducer provided by the present invention, the first arched membrane unit surrounds the first planar membrane unit and is arranged along the edge of the first membrane; the second arched membrane unit surrounds the second planar membrane unit and is arranged along the edge of the second membrane.

[0009] For a microelectromechanical system transducer provided by the present invention, the microelectromechanical system transducer is a microelectromechanical system microphone; the first membrane is the first sound membrane of the microelectromechanical system microphone; the second membrane is the second sound membrane of the microelectromechanical system microphone; the microelectromechanical system transducer further includes: a stator, arranged in the vacuum cavity.

[0010] For a microelectromechanical system transducer provided by the present invention, the microelectromechanical system transducer is a microelectromechanical system accelerometer, the microelectromechanical system accelerometer includes a thin-film mass block; the first membrane is the first thin-film layer of the thin-film mass block; the second membrane is the second thin-film layer of the thin-film mass block.

[0011] The present invention provides a method for manufacturing a microelectromechanical system transducer, comprising: forming a first sacrificial layer above a substrate; wherein, the thickness of the first sacrificial layer is not less than the longitudinal length of the first arched membrane unit; using a mask plate to perform overlay etching and etching on the first sacrificial layer to obtain the first sacrificial layer with an arc-shaped surface morphology; forming the first arched membrane unit on the surface of the first sacrificial layer with the arc-shaped surface morphology; forming a second sacrificial layer on the upper surface of the first arched membrane unit; using the second sacrificial layer as a base to form the support column at the edge of the first arched membrane unit; forming a third sacrificial layer on the upper surface of the second sacrificial layer; using a mask plate to perform overlay etching and etching on the third sacrificial layer to obtain the third sacrificial layer with an arched surface morphology; forming the second arched membrane unit on the upper surface of the third sacrificial layer with the arched surface morphology.

[0012] For a method for manufacturing a microelectromechanical system transducer provided by the present invention, the step of using a mask plate to perform overlay etching and etching on the first sacrificial layer to obtain the first sacrificial layer with an arc-shaped surface morphology includes: Using multiple masks, a plurality of blocking layers in the shape of rings that are connected but do not intersect are sequentially formed on the surface of the first sacrificial layer; wherein, the light-transmitting area of each mask corresponds to a ring shape of a preset size, and through the sequential use of the multiple masks, the plurality of blocking layers are nested to form; for each of the blocking layers, alignment and etching processes are respectively performed to make the first sacrificial layer form a stepped topography that descends from both sides to the center; the first sacrificial layer with the stepped topography is isotropically etched to obtain the first sacrificial layer with an arc-shaped topography.

[0013] According to a method for manufacturing a MEMS transducer provided by the present invention, the step of using a mask to perform alignment and etching on the third sacrificial layer to obtain the third sacrificial layer with a domed topography includes: using multiple masks to sequentially form a plurality of blocking layers in the shape of rings that are connected but do not intersect on the surface of the third sacrificial layer; wherein, the light-transmitting area of each mask corresponds to a ring shape of a preset size, and through the sequential use of the multiple masks, the plurality of blocking layers are nested to form; for each blocking layer, alignment and etching processes are respectively performed to make the third sacrificial layer form a stepped topography that descends from the center to both sides; the third sacrificial layer with the stepped topography is isotropically etched to obtain the third sacrificial layer with a domed topography.

[0014] According to a method for manufacturing a MEMS transducer provided by the present invention, the MEMS transducer is a MEMS microphone; the first arched film unit is the first arched film unit included in the first sound film of the MEMS microphone; the second arched film unit is the second arched film unit included in the second sound film of the MEMS microphone; the method further includes: forming a stator in the vacuum cavity formed by the first arched film unit and the second arched film unit.

[0015] According to a method for manufacturing a MEMS transducer provided by the present invention, the MEMS transducer is a MEMS accelerometer, and the MEMS accelerometer includes a thin-film mass block; the first arched film unit is the first arched film unit included in the first thin-film layer of the thin-film mass block; the second arched film unit is the second arched film unit included in the second thin-film layer of the thin-film mass block.

[0016] The MEMS transducer provided by the present invention has a double-membrane structure: the first membrane includes at least one first arched membrane unit, and the second membrane includes at least one second arched membrane unit symmetrically arranged with respect to the first arched membrane unit. Due to the arched design, the first arched membrane unit and the second arched membrane unit can effectively slow down the pressure directed towards the center of the two membranes generated due to the internal and external pressure difference. Therefore, the MEMS transducer provided by the present invention can effectively reduce the number of support pillars used compared to the MEMS transducers of the prior art, thereby forming a sparse support structure. The reduction in the support pillar density not only reduces the transfer impedance of the stator structure but also effectively alleviates the stress concentration phenomenon on the surface of the thin film. Thereby, the sensitivity and stability of the sealed double-membrane structure MEMS transducer can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of the MEMS transducer provided by the present invention.

[0019] Figure 2 It is a schematic flowchart of the method for manufacturing the MEMS transducer provided by the present invention.

[0020] Figure 3 It is a schematic flowchart of the method for manufacturing the first sacrificial layer with an arc-shaped topography provided by the present invention.

[0021] Figure 4 It is a schematic flowchart of the method for manufacturing the third sacrificial layer with an arc-shaped topography provided by the present invention.

[0022] Figure 5 It is a schematic diagram of the process for forming the first sacrificial layer with a stepped topography provided by the present invention.

[0023] Figure 6 It is a schematic structural diagram of the first sacrificial layer with an arc-shaped topography provided by the present invention.

[0024] Figure 7 It is a schematic structural diagram of the first arched membrane unit formed on the first sacrificial layer with an arc-shaped topography provided by the present invention.

[0025] Figure 8 It is a schematic structural diagram of the second sacrificial layer deposited on the first arched membrane unit provided by the present invention.

[0026] Figure 9It is a schematic diagram of the process of forming the second arched film unit on the third sacrificial layer provided by the present invention. Detailed implementation manners

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts fall within the protection scope of the present invention.

[0028] The following combines Figure 1 - Figure 2 to describe the microelectromechanical system transducer of the present invention.

[0029] Figure 1 It is a schematic structural diagram of the microelectromechanical system transducer provided by the present invention.

[0030] The microelectromechanical system transducer is a device manufactured based on microelectromechanical system technology and is used to convert vibration energy into electrical energy. For example, a microelectromechanical system microphone, etc.

[0031] As Figure 1 shown, the microelectromechanical system transducer includes the following components.

[0032] The first film, and the first film includes at least one first arched film unit.

[0033] The second film, and the second film has at least one second arched film unit symmetrically arranged with the first arched film unit.

[0034] In some embodiments, the microelectromechanical system transducer is a microelectromechanical system microphone. The first film is the first sound film of the microelectromechanical system microphone; the second film is the second sound film of the microelectromechanical system microphone; the microelectromechanical system transducer further includes: a stator, which is arranged in a vacuum cavity.

[0035] In some embodiments, the microelectromechanical system transducer is a microelectromechanical system accelerometer, and the microelectromechanical system accelerometer includes a thin film mass block; the first film is the first thin film layer of the thin film mass block; the second film is the second thin film layer of the thin film mass block.

[0036] The first film and the second film together constitute two major film layers in the microelectromechanical system sealed double-film structure.

[0037] The first arched film unit is a film unit with an arched structure in the first film. The second arched film unit is a film unit with an arched structure in the second film. The first arched film unit and the second arched film unit are symmetrically arranged (for example, mirror-symmetrically arranged).

[0038] In some embodiments, the first membrane may be composed of a first arched membrane unit. Correspondingly, the second membrane may be composed of a second arched membrane unit.

[0039] In some embodiments, the first membrane may be composed of multiple first arched membrane units. Correspondingly, the second membrane may be composed of multiple second arched membrane units.

[0040] In some embodiments, the first membrane further includes a first planar membrane unit; the second membrane further includes a second planar membrane unit. Both the first planar membrane unit and the second planar membrane unit are membrane units with a flat surface. In this embodiment, the first arched membrane unit and the first planar membrane unit can be arranged in the first mold in various ways. Correspondingly, the second arched membrane unit and the second planar membrane unit can be arranged in the second mold in various ways.

[0041] Merely by way of example, the first arched membrane unit surrounds the first planar membrane unit and is arranged along the edge of the first membrane; the second arched membrane unit surrounds the second planar membrane unit and is arranged along the edge of the second membrane. For example, the diameter of the membrane sheet of the first membrane is 1 millimeter. The first arched membrane units are arranged in sequence along the edge of the first membrane, and the width of each first arched membrane unit is 0.1 millimeter. The remaining part of the first membrane is provided with the first planar membrane unit, and the second membrane is arranged correspondingly.

[0042] Support columns, with both ends of the support columns fixedly connected to the first arched membrane unit and the second arched membrane unit respectively.

[0043] In the specific implementation process, the shape of the support columns can be designed according to actual application requirements, not limited by the description in this specification. For example, the support columns can be in the shape of a hollow cylinder.

[0044] Vacuum cavity, formed by jointly surrounding the first arched membrane unit, the second arched membrane unit and the support columns.

[0045] The support columns ensure the consistency of the phase and swing amplitude of the symmetrically arranged first arched membrane unit and the second arched membrane unit during vibration, so as to generate a True Differential signal relative to a certain fixed part, and this signal serves as the output of the microelectromechanical system transducer part. The following formula is the calculation formula for the output signal of the microelectromechanical system transducer.

[0046] y1 and y2 respectively represent the output signals generated by the first membrane and the second membrane. x is the input excitation. Perform Taylor expansion on y1 and y2: Subtracting them gives the output signal of the microelectromechanical system transducer: Among them, , , are Taylor coefficients.

[0047] As can be seen from the above calculation formula, the dual-mode structure of the MEMS transducer provided by the present invention can eliminate the even harmonics of the output signal and reduce the total harmonic distortion of the sensor.

[0048] Next, a method for manufacturing a MEMS transducer of the present invention will be described in conjunction with Figure 2 - Figure 9 A method for manufacturing a MEMS transducer of the present invention will be described.

[0049] Figure 2 is a schematic flow chart of a method for manufacturing a MEMS transducer provided by the present invention. As shown in Figure 2 , the method includes the following: Step 201: Form a first sacrificial layer above the substrate.

[0050] In a specific implementation process, a first sacrificial layer can be deposited on the substrate using various materials (for example, silicon oxide), and the thickness of the first sacrificial layer is controlled to be not less than the longitudinal length of the first arch-shaped film unit.

[0051] Step 202: Use a mask to perform alignment and etching on the first sacrificial layer to obtain a first sacrificial layer with a curved surface morphology.

[0052] In a specific implementation process, in various ways, a mask can be used to perform alignment and etching on the first sacrificial layer to obtain a first sacrificial layer with a curved surface morphology as shown in Figure 6 .

[0053] For an embodiment of using a mask to perform alignment and etching on the first sacrificial layer to obtain a first sacrificial layer with a curved surface morphology, refer to the relevant content in Figure 3 , which will not be elaborated here.

[0054] Step 203: Form a first arch-shaped film unit on the surface of the first sacrificial layer with a curved surface morphology.

[0055] In a specific implementation process, a first arch-shaped film unit as shown in Figure 7 can be formed on the surface of the first sacrificial layer.

[0056] Step 204: Form a second sacrificial layer on the upper surface of the first arch-shaped film unit.

[0057] As shown in Figure 8 , deposit a second sacrificial layer on the upper surface of the first arch-shaped film unit as a filling between the first arch-shaped film unit and the second arch-shaped film unit. After the deposition is completed, the surface of the second sacrificial layer is polished, such as chemical or mechanical polishing, to facilitate the arrangement of other necessary structures or the progress of the process.

[0058] Step 205: Using the second sacrificial layer as a base, form support pillars at the edge of the first arch-shaped membrane unit.

[0059] In the specific implementation process, common methods can be used to form the support pillars.

[0060] Step 206: Form a third sacrificial layer on the upper surface of the second sacrificial layer.

[0061] The third sacrificial layer is used as the sacrificial layer for forming the second arch-shaped membrane unit.

[0062] Step 207: Using a mask, perform overlay and etching processes on the third sacrificial layer to obtain a third sacrificial layer with an arch-shaped topography.

[0063] In the specific implementation process, in various ways, using a mask, perform overlay and etching processes on the third sacrificial layer to obtain a third sacrificial layer with an arch-shaped topography, which is not limited by the description in this specification.

[0064] Regarding an embodiment of using a mask to perform overlay and etching processes on the third sacrificial layer to obtain a third sacrificial layer with an arch-shaped topography, see Figure 4 the relevant content therein, which will not be elaborated here.

[0065] Step 208: Form a second arch-shaped membrane unit on the upper surface of the third sacrificial layer with an arch-shaped topography.

[0066] As Figure 9 shown, form a second arch-shaped membrane unit on the upper surface of the third sacrificial layer with an arch-shaped topography. After the second arch-shaped membrane unit is fabricated, the remaining sacrificial layer can be removed using common methods (such as dry etching, etc.) to obtain a microelectromechanical system transducer.

[0067] In some embodiments, the microelectromechanical system transducer is a microelectromechanical system microphone. The first arch-shaped membrane unit is the first arch-shaped membrane unit included in the first sound membrane of the microelectromechanical system microphone; the second arch-shaped membrane unit is the second arch-shaped membrane unit included in the second sound membrane of the microelectromechanical system microphone. After the fabrication of the first arch-shaped membrane unit and the second arch-shaped membrane unit is completed, a stator also needs to be formed in the vacuum cavity formed by the first arch-shaped membrane unit and the second arch-shaped membrane unit.

[0068] In some embodiments, the microelectromechanical system transducer is a microelectromechanical system accelerometer, and the microelectromechanical system accelerometer includes a thin-film mass block; the first arch-shaped membrane unit is the first arch-shaped membrane unit included in the first thin-film layer of the thin-film mass block; the second arch-shaped membrane unit is the second arch-shaped membrane unit included in the second thin-film layer of the thin-film mass block. After obtaining the thin-film mass block using the above method, the fabrication of other components in the microelectromechanical system accelerometer also needs to be completed.

[0069] Figure 3It is a schematic flow chart of the method for manufacturing the first sacrificial layer with a spherical surface topography provided by the present invention. As Figure 3 shown, the method includes the following: Step 301: Using a plurality of masks, a plurality of blocking layers in the shape of connected but non-intersecting rings are sequentially formed on the surface of the first sacrificial layer.

[0070] The light-transmitting area of each mask corresponds to a ring shape of a preset size. By sequentially using a plurality of masks, a plurality of blocking layers are nested and formed.

[0071] As Figure 5 shown, through mask 1, a blocking layer 1 in the shape of a ring can be generated, and step 1 is formed by subsequent processing; through mask 2, step 2 is formed by subsequent processing; through mask 3, step 3 is formed by subsequent processing... Among them, the inner diameter of mask 1 is equal to the outer diameter of mask 2; the inner diameter of mask 2 is equal to the outer diameter of mask 3, and so on.

[0072] In the specific implementation process, according to the needs of the implementation process, a plurality of masks can be used, and the finally formed stepped steps can be n (n>=2). The specific value of n depends on the curvature of the formed curved surface. The greater the curvature, the more steps n are required to more accurately simulate the curved surface shape.

[0073] Step 302: For each blocking layer, alignment and etching processes are respectively performed to make the first sacrificial layer form a stepped topography that descends from both sides to the center.

[0074] In the specific implementation process, it is necessary to start from the innermost blocking layer and sequentially perform alignment and etching processes, so as to form a stepped topography that descends from both sides to the center.

[0075] Step 303: Isotropic etching is performed on the first sacrificial layer with the stepped topography to obtain the first sacrificial layer with a spherical surface topography.

[0076] In the specific implementation process, various methods can be used to perform isotropic etching on the first sacrificial layer with the stepped topography. For example, wet etching, etc., and finally form Figure 6 the spherical surface shown.

[0077] In the embodiments provided by the present invention, by using a plurality of masks with different light-transmitting area sizes, a plurality of blocking layers in the shape of connected but non-intersecting rings can be accurately formed on the surface of the first sacrificial layer. Since the size and position of each blocking layer can be flexibly adjusted, high-precision stepped topography processing can be achieved. By respectively performing alignment and etching processes on each blocking layer, a stepped topography that descends from both sides to the center can be gradually formed on the first sacrificial layer. Subsequently, high-precision spherical surface processing can be realized based on the complex stepped topography.

[0078] Figure 4 is a schematic flowchart of the method for manufacturing the third sacrificial layer with a curved surface topography provided by the present invention. As Figure 4 shown, the method includes the following: Step 401: Using a plurality of masks, a plurality of blocking layers in the shape of connected but non-intersecting rings are sequentially formed on the surface of the third sacrificial layer.

[0079] The light-transmitting area of each mask corresponds to a ring shape of a preset size. By sequentially using a plurality of masks, a plurality of blocking layers are nested and formed.

[0080] In a specific implementation process, in order to obtain a second arched film unit that is mirror-symmetrical to the first arched film unit, the same plurality of masks as in step 301 can be used to form a plurality of blocking layers on the surface of the third sacrificial layer.

[0081] For a detailed description of the plurality of masks, refer to the relevant content in step 301, which will not be elaborated here.

[0082] Step 402: For each blocking layer, perform overlay and etching processes respectively, so that the third sacrificial layer forms a stepped topography that descends from the center to both sides.

[0083] In a specific implementation process, it is necessary to start from the outermost blocking layer and perform overlay and etching processes in sequence, so as to form a stepped topography that descends from the center to both sides as Figure 9 shown.

[0084] Step 403: Perform isotropic etching on the third sacrificial layer with the stepped topography to obtain the third sacrificial layer with a curved surface topography.

[0085] In a specific implementation process, various methods can be used to perform isotropic etching on the third sacrificial layer with the stepped topography. For example, wet etching, etc. Finally, an arch as Figure 9 shown is formed.

[0086] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the above technical solutions, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disc, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A micro-electromechanical system transducer, characterized in that: include: a first membrane, the first membrane comprising at least one first arched membrane unit; a second membrane, the second membrane having at least one second arched membrane unit symmetrically arranged with respect to the first arched membrane unit; A supporting column, two ends of which are respectively fixedly connected to the first arched membrane unit and the second arched membrane unit; The vacuum chamber is formed by the first arched membrane unit, the second arched membrane unit and the supporting column.

2. The MEMS transducer according to claim 1, characterized in that: The first membrane also includes a first planar membrane unit; The second membrane further includes a second planar membrane unit.

3. The MEMS transducer according to claim 2, characterized in that: The first arched membrane unit surrounds the first planar membrane unit and is arranged along the edge of the first membrane; The second arched membrane unit surrounds the second planar membrane unit and is arranged along an edge of the second membrane.

4. The MEMS transducer according to any one of claims 1 to 3, characterized in that: The MEMS transducer is a MEMS microphone; The first membrane is a first sound membrane of the micro-electromechanical system microphone; The second membrane is a second sound membrane of the micro-electromechanical system microphone; The micro-electromechanical system transducer also includes: The stator is arranged in the vacuum chamber.

5. The MEMS transducer according to any one of claims 1 to 3, characterized in that: The MEMS transducer is a MEMS accelerometer, and the MEMS accelerometer includes a thin film mass; The first film is a first film layer of the film proof block; The second film is a second film layer of the thin film proof block.

6. A method for manufacturing a micro-electromechanical system transducer, characterized in that: The method is used to manufacture the micro-electromechanical system transducer according to claim 1, and the method comprises: forming a first sacrificial layer above the substrate; wherein the thickness of the first sacrificial layer is not less than the longitudinal length of the first arched membrane unit; Using a mask, performing overlay and etching processing on the first sacrificial layer to obtain the first sacrificial layer with a curved surface morphology; forming the first arched membrane unit on the surface of the first sacrificial layer having a curved surface; forming a second sacrificial layer on the upper surface of the first arched membrane unit; Taking the second sacrificial layer as a base, forming the support column at the edge of the first arched membrane unit; forming a third sacrificial layer on the upper surface of the second sacrificial layer; Using a mask, performing overlay and etching processing on the third sacrificial layer to obtain the third sacrificial layer with an arched surface morphology; The second arched membrane unit is formed on the upper surface of the third sacrificial layer having an arched surface morphology.

7. The method for manufacturing a MEMS transducer according to claim 6, characterized in that: The method of using a mask to perform overlay and etching on the first sacrificial layer to obtain the first sacrificial layer with a curved surface morphology includes: Using a plurality of masks, a plurality of barrier layers in the shape of circular rings that are connected but not intersecting are sequentially generated on the surface of the first sacrificial layer; wherein the light-transmitting area of ​​each mask corresponds to a circular ring shape of a preset size, and the plurality of barrier layers are nested and formed by sequentially using the plurality of masks; For each of the barrier layers, respectively, overlay and etching are performed to form a step morphology of the first sacrificial layer descending from both sides to the center; The first sacrificial layer having a step morphology is isotropically etched to obtain the first sacrificial layer having a curved surface morphology.

8. The method for manufacturing a MEMS transducer according to claim 7, characterized in that: The method of using a mask to perform overlay and etching on the third sacrificial layer to obtain the third sacrificial layer with an arched surface morphology includes: Using a plurality of masks, a plurality of barrier layers in the shape of circular rings that are connected but not intersecting are sequentially generated on the surface of the third sacrificial layer; wherein the light-transmitting area of ​​each mask corresponds to a circular ring shape of a preset size, and the plurality of barrier layers are nested to form the plurality of mask layers by sequentially using the plurality of masks; For each barrier layer, overlay and etching are performed respectively, so that the third sacrificial layer forms a step morphology descending from the center to both sides; The third sacrificial layer with a step morphology is isotropically etched to obtain the third sacrificial layer with an arched surface morphology.

9. The method for manufacturing a MEMS transducer according to claim 6, characterized in that: The MEMS transducer is a MEMS microphone; The first arched membrane unit is a first arched membrane unit included in the first sound membrane of the micro-electromechanical system microphone; The second arched membrane unit is a second arched membrane unit included in the second sound membrane of the micro-electromechanical system microphone; The method further comprises: A stator is formed in the vacuum chamber formed by the first arched membrane unit and the second arched membrane unit.

10. The method for manufacturing a MEMS transducer according to claim 6, characterized in that: The MEMS transducer is a MEMS accelerometer, and the MEMS accelerometer includes a thin film mass; The first arched membrane unit is a first arched membrane unit included in the first membrane layer of the membrane mass block; The second arched membrane unit is a second arched membrane unit included in the second membrane layer of the membrane proof block.

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