Piezoelectric MEMS transducer device, method of manufacturing same, and electronic device comprising same

Abstract

The present invention relates to a piezoelectric MEMS transducer device, a method of manufacturing a piezoelectric MEMS transducer device, and an electronic apparatus including the same. The piezoelectric MEMS transducer device comprises an external circuit and at least one piezoelectric MEMS transducer which are laminated in the thickness direction of the transducer device, wherein an electrical connection channel is arranged between the piezoelectric MEMS transducer and the external circuit; in a top view parallel to the thickness direction of the transducer device, the electrical connection channel at least partially overlaps the corresponding piezoelectric MEMS transducer.

Description

Technical Field

[0001] Embodiments of the present invention relate to the semiconductor field, and in particular, to a piezoelectric MEMS transducer device, a manufacturing method thereof, and an electronic device comprising the same. Background Art

[0002] Devices based on piezoelectric materials have penetrated into all aspects of modern society. Traditional piezoelectric devices are mainly based on bulk materials such as quartz or ceramics. They are not only bulky and expensive, but also difficult to manufacture in a continuous production mode, so they are limited to some special applications or high-end applications. Since the beginning of the 21st century, with the continuous development of advanced materials and semiconductor technology, the integration of piezoelectric thin film material deposition technology and MEMS (Micro-electromechanical Systems) / CMOS (Complementary Metal Oxide Semiconductor) manufacturing processes has become increasingly high, opening up a new path for MEMS transducers based on piezoelectric films. There are three types of piezoelectric MEMS transducers: 1. Sensors that convert other forms of signals / energy into electrical signals / energy, such as piezoelectric MEMS microphones, piezoelectric MEMS energy harvesters, piezoelectric MEMS inertial devices, etc.; 2. Actuators that convert electrical signals / energy into other forms of signals / energy, such as piezoelectric MEMS switches, piezoelectric MEMS speakers, piezoelectric MEMS inkjet print heads, etc.; 3. Devices that convert electrical signals / energy into other forms of signals / energy and then convert them back to electrical signals / energy, such as piezoelectric MEMS filters, piezoelectric MEMS ultrasonic transducers (PMUT), etc. 5G communications, personal voice assistants, wearable detection, and medical imaging equipment are all popular applications for piezoelectric MEMS transducers.

[0003] Taking the ultrasonic transducer as an example, the ultrasonic imager uses the ultrasonic transducer to transmit ultrasonic waves to human tissues, organs and other imaging targets, receives the reflected ultrasonic signals through the ultrasonic transducer, processes the signals and presents the target information on the display in the form of images. As a signal transceiver, the ultrasonic transducer is one of the core components of the ultrasonic imager. The use of mechanical cutting solutions to manufacture ultrasonic transducers is limited in terms of the miniaturization of the size of the vibration unit, as well as production costs, efficiency, product consistency and yield, and cannot meet the further development of ultrasonic imagers, especially in terms of low cost, portability, high resolution and other requirements. The MEMS manufacturing technology based on the semiconductor industry is a very effective way to efficiently, low-cost and mass-produce small-sized devices. The piezoelectric MEMS ultrasonic transducer PMUT can be integrated with CMOS circuits to achieve low-cost, consistent and large-scale manufacturing of miniature ultrasonic transducers with high integration and strong computing power.

[0004] Piezoelectric MEMS transducers usually need to array transducer elements to achieve their functions. For example, PMUT imaging requires individually controlled PMUT elements to form an array to realize ultrasonic transmission and reception. Piezoelectric MEMS oscillators need to make compact electrical connections between resonators and control circuits to achieve ultra-small size integration. Piezoelectric MEMS switches require individually controlled switch elements to form an array to achieve multi-channel on-off control. Piezoelectric MEMS inkjet print heads require thousands of piezoelectric MEMS to perform element integration and make independent electrical connections, etc. The integration of elements / arrays is usually high, and the integration of high-density piezoelectric MEMS transducers is a prerequisite for achieving high performance. Since the elements / arrays require electrode leads to realize the input and output of their electrical signals, the electrical signal input / output method of high-density piezoelectric MEMS transducer arrays is usually limited by size and space, that is, the electrode leads of each element occupy a certain size and space, which reduces the achievable density between piezoelectric MEMS transducer elements to a certain extent, especially when the element size is smaller, the negative impact of the electrode leads on the achievable density is more serious. It is necessary to develop an integration and electrical connection solution for piezoelectric MEMS transducer arrays with high filling density and small element spacing. Summary of the invention

[0005] The present invention is proposed to alleviate or solve at least one aspect of the above-mentioned problems in the prior art.

[0006] According to one aspect of an embodiment of the present invention, a piezoelectric MEMS transducer device is provided, comprising:

[0007] An external circuit and at least one piezoelectric MEMS transducer are stacked in a thickness direction of the transducer device,

[0008] in:

[0009] An electrical connection channel is provided between the piezoelectric MEMS transducer and the external circuit;

[0010] In a top view parallel to the thickness direction of the transducer device, the electrical connection channel at least partially overlaps with the piezoelectric MEMS transducer.

[0011] According to one aspect of an embodiment of the present invention, a method for manufacturing a piezoelectric MEMS transducer device is provided, comprising the steps of:

[0012] Provide external circuits;

[0013] An electrical connection channel including a horizontal circuit and a vertical circuit is formed above the external circuit, wherein the vertical circuit is electrically connected to the external circuit;

[0014] forming a MEMS transducer, wherein the MEMS transducer is electrically connected to the lateral circuit,

[0015] in:

[0016] The method further comprises the step of causing the electrical connection channel to at least partially overlap the MEMS transducer in a top view parallel to the thickness direction of the transducer device.

[0017] An embodiment of the present invention also relates to an electronic device, comprising the above-mentioned piezoelectric MEMS transducer device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following description and accompanying drawings may better help understand these and other features and advantages of various embodiments disclosed by the present invention, in which the same reference numerals always represent the same components, wherein:

[0019] Figure 1 It is a top view schematic diagram of a piezoelectric MEMS transducer device in the prior art;

[0020] Figure 2 is a schematic cross-sectional view of a piezoelectric MEMS transducer device according to a first embodiment of the present invention;

[0021] Figure 3 for Figure 2 A schematic top view of a medium-sized piezoelectric MEMS transducer device;

[0022] Figure 4 is a schematic cross-sectional view of a piezoelectric MEMS transducer device according to a second embodiment of the present invention;

[0023] Figure 5 is a schematic cross-sectional view of a piezoelectric MEMS transducer device according to a third embodiment of the present invention;

[0024] Figure 6-Figure 11FIG. 4 is a schematic diagram of a method for manufacturing a piezoelectric MEMS transducer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further specifically described below through examples and in conjunction with the accompanying drawings. In the specification, the same or similar figure numbers indicate the same or similar parts. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be understood as a limitation of the present invention. Some embodiments of the invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0026] In the present invention, “longitudinal direction” may refer to the thickness direction of the transducer device, and “lateral direction” may refer to the direction perpendicular to the thickness of the transducer device.

[0027] Figure 1 Figure 1 is a top view of a PMUT array integrated on a CMOS circuit, where white circles represent PMUT units and black circles represent electrical channels. Figure 1 As shown, in the prior art, the connection between the PMUT electrode and the CMOS electrode is achieved through an electrical channel that exists in the lateral direction of the PMUT vibration unit, that is, the electrical channel is on the side of the PMUT vibration cavity, which occupies the area of ​​the CMOS unit, reduces the area of ​​the PMUT vibration unit, and increases the spacing between the vibration elements. However, the transmission and reception performance of the ultrasonic transducer are directly related to the area of ​​the PMUT vibration unit. The higher the density of the vibration unit per unit area, the larger the area, the greater the ultrasonic transmission sound pressure, and the higher the receiving sensitivity. Increasing the filling density of the PMUT vibration unit is the only way to obtain a PMUT array with excellent performance. At the same time, reducing the spacing between the vibration units can also enhance the coupling between the vibration elements, improve the imaging core performance indicators such as the bandwidth of the ultrasonic transducer, and help obtain good imaging effects.

[0028] In the present invention, in a top view parallel to the thickness direction of the transducer device, the electrical connection channel at least partially overlaps with the piezoelectric MEMS transducer, which can effectively reduce the ineffective occupation of the wafer surface area by the electrical connection channel, increase the filling density of the piezoelectric MEMS transducer array elements, reduce the array element spacing, and obtain a high-density, highly integrated piezoelectric MEMS transducer.

[0029] Referring to the accompanying drawings, the present invention proposes a piezoelectric MEMS transducer device, comprising: an external circuit and at least one piezoelectric MEMS transducer stacked in the thickness direction of the transducer device, wherein: an electrical connection channel is arranged between the piezoelectric MEMS transducer and the external circuit, and the electrical connection channel at least partially overlaps with the piezoelectric MEMS transducer in the thickness direction of the transducer device.

[0030] Figure 2 FIG. 4 is a cross-sectional schematic diagram of a piezoelectric MEMS transducer device according to a first embodiment of the present invention. Figure 2 As shown, the piezoelectric MEMS transducer device includes a piezoelectric MEMS transducer and an external circuit. The piezoelectric MEMS transducer is a PMUT unit 200, and the external circuit is a CMOS circuit, which includes a CMOS substrate. Figure 2 As shown, a protective layer 110 is disposed on the CMOS substrate 100. The CMOS substrate 100, the protective layer 110 and the PMUT unit 200 are stacked in sequence from bottom to top. The material of the CMOS substrate 100 is, for example, silicon. The material of the protective layer 110 is, for example, silicon oxide or silicon nitride.

[0031] The PMUT unit 200 and the CMOS circuit are electrically connected via an electrical connection channel. Figure 6 As shown, illustratively, the CMOS circuit includes an electrical connection portion 119, intra-layer circuits 113 and 115, and inter-layer circuits 112 and 114. Figure 2 and Figure 6 The electrical connection channel includes a transverse circuit 116 and a vertical circuit 117 which are electrically connected to each other. The transverse circuit 116 extends perpendicular to the thickness direction of the transducer device, and the vertical circuit 117 extends along the thickness direction of the transducer device. Figure 2 In the illustrated embodiment, the vertical circuit 117 is located within the protective layer 110 .

[0032] In the present invention, in a top view parallel to the thickness direction of the transducer device, the electrical connection channel at least partially overlaps with the piezoelectric MEMS transducer, so as to reduce the lateral space occupied by the electrical connection channel. Further, in a top view parallel to the thickness direction of the transducer device, the electrical connection channel completely overlaps with the piezoelectric MEMS transducer.

[0033] See also Figure 2 , there is a bonding interface between the horizontal circuit 116 and the vertical circuit 117. In other embodiments, although not shown, the horizontal circuit 116 and the vertical circuit 117 can be formed as a whole.

[0034] In an optional embodiment, a plurality of PMUT units 200 may be arranged laterally into a PMUT array. Each PMUT unit 200 in the PMUT array is electrically connected to the CMOS circuit via a corresponding electrical connection channel below. The PMUT array generally includes more than 5 PMUT units 200, each unit constituting an array element. Accordingly, in the present invention, the piezoelectric MEMS transducer may be in the form of an array, and the array includes more than 5 piezoelectric MEMS transducer array elements.

[0035] Figure 3 for Figure 2 A top view of the medium-sized piezoelectric MEMS transducer device, where the white circle represents the PMUT unit. Figure 3 and Figure 1 It can be seen that the piezoelectric MEMS transducer device in the present invention can effectively reduce the ineffective occupation of the wafer in-plane area by the electrical connection channel, increase the filling density of the piezoelectric MEMS transducer array elements, reduce the array element spacing, and obtain a high-density, high-integration piezoelectric MEMS transducer.

[0036] Figure 4 FIG. 4 is a schematic cross-sectional view of a piezoelectric MEMS transducer device according to a second embodiment of the present invention.

[0037] like Figure 4 As shown, the piezoelectric MEMS transducer device includes a MEMS switch 300 and an external circuit 400. The external circuit 400 is, for example, an IC (Integrated Circuit) chip or a MEMS device. An interposer 500 is also provided between the MEMS switch 300 and the external circuit 400.

[0038] like Figure 4 As shown, the electrical connection channel between the MEMS switch 300 and the external circuit 400 includes a conductive via 310 located in the MEMS switch 300, a conductive via 320 located in the substrate of the MEMS switch 300, and a conductive via 330 located in the transfer layer 500. The conductive vias overlap with the MEMS switch 300 vertically, reducing the interconnection area.

[0039] It should be pointed out that in Figure 4 In the embodiment of FIG. 5 , the transfer layer 500 may not be provided. In this case, the MEMS switch 300 is directly electrically connected to the external circuit 400 through the conductive vias 310 and the conductive vias 320 .

[0040] Figure 5 FIG. 4 is a cross-sectional schematic diagram of a piezoelectric MEMS transducer device according to a third embodiment of the present invention. Figure 5 As shown, the piezoelectric MEMS transducer device includes a MEMS resonator 600 and an external circuit 700. The MEMS resonator 600 is disposed on a substrate 610. The substrate 610 is bonded to the external circuit 700. The substrate 610 has a cavity.

[0041] like Figure 5As shown, the electrical connection channel between the piezoelectric MEMS resonator 600 and the external circuit 700 includes a conductive via 630 electrically connected to the gap electrode 620 located in the cavity of the substrate 610 and passing through the substrate 610. The electrical connection channel overlaps the MEMS resonator 600 vertically, reducing the interconnection area.

[0042] exist Figure 5 In the figure, the piezoelectric MEMS resonator includes a substrate, a bottom electrode, a piezoelectric layer and a top electrode. The piezoelectric MEMS transducer includes a first MEMS resonator and a second MEMS resonator arranged adjacent to each other in the lateral direction, the bottom electrode of the first MEMS resonator (the right resonator in the figure) is electrically connected to the top electrode of the second MEMS resonator (the left resonator in the figure), and the bottom electrode of the first MEMS resonator is electrically connected to an external circuit via the conductive through hole passing through the substrate.

[0043] like Figure 5 As shown, the two MEMS resonators on the left and right (or one or more) and the circuit at the bottom (such as an IC circuit) form a MEMS oscillator. The connection between the MEMS resonator and the circuit can be completed through a through hole in the silicon substrate. The through hole is below the MEMS resonator, and the area of ​​the entire oscillator is reduced by reducing the plane area of ​​the electrical interconnection between the resonator and the circuit. The lower electrode of the MEMS resonator leads out the electrical signal through the cavity in the silicon substrate and the through hole in the silicon substrate to achieve interconnection. In this embodiment, the connection between the MEMS resonator and the external circuit below is completed through the through hole in the silicon substrate.

[0044] Figure 5 The embodiment shown can also be used as an example of a high-density MEMS inkjet print head. The left and right MEMS inkjet actuator units (or multiple units) form a MEMS inkjet print head. The MEMS inkjet actuator units can be connected through through holes in the silicon substrate. The through holes are below the MEMS inkjet actuator units, and the area of ​​the entire inkjet print head is reduced by reducing the planar area of ​​the electrical interconnection between the MEMS inkjet actuator units. In this embodiment, the lower electrode of the MEMS inkjet actuator unit leads out the electrical signal through the cavity in the silicon substrate and the through hole in the silicon substrate to achieve interconnection. Similarly, the connection between the MEMS inkjet actuator unit and the external circuit can also be completed through the through hole in the silicon substrate.

[0045] Based on the above, as can be understood, in the present invention, the specific type of the piezoelectric MEMS transducer is not limited, such as a PMUT unit, a MEMS switch, a MEMS resonator, a MEMS inkjet actuator or a MEMS speaker. The type of the external circuit is not limited, such as a CMOS circuit, a substrate, a PCB, a MEMS device or an interposer.

[0046] An embodiment of the present invention also provides a method for manufacturing a piezoelectric MEMS transducer device.

[0047] Figure 6-Figure 11 FIG. 1 is a schematic diagram of a method for manufacturing a piezoelectric MEMS transducer device according to an embodiment of the present invention, which takes a PMUT unit as an example. Figure 6-Figure 11 , the method may include the following steps:

[0048] Step 1: Figure 6 As shown, a CMOS substrate 100 is provided, a protective layer 110 is provided on the surface of the CMOS substrate 100, and an electrical connection portion 119 is provided in the protective layer 110. In addition, the protective layer 110 also includes intra-layer circuits 113 and 115, inter-layer circuits 112 and 114, a source and drain 101 of a transistor, and a gate 111 of a transistor.

[0049] Step 2: Figure 7 As shown, the protective layer 110 is etched to expose the electrical connections 119 .

[0050] Step 3: Figure 8 As shown, a horizontal circuit 116 and a vertical circuit 117 are deposited on the protective layer 110, wherein the vertical circuit 117 is electrically connected to the electrical connection portion 119. The horizontal circuit 116 and the vertical circuit 117 can be deposited at one time or separately. In the case where the horizontal circuit 116 and the vertical circuit 117 can be deposited at one time, the horizontal circuit 116 has a downwardly concave morphology at a position corresponding to the electrical connection portion 119.

[0051] Step 4: Figure 9-11 As shown, a PMUT unit is formed on the protection layer 110 , and the PMUT unit includes a top electrode, a piezoelectric layer, and a bottom electrode, wherein the electrodes of the PMUT unit are electrically connected to the corresponding lateral circuit 116 .

[0052] Step 4 may further include:

[0053] Step 4-1: Fig. 9 As shown, a sacrificial material 200 is disposed on the lateral circuit 116 and the protection layer 110 .

[0054] Step 4-2: Fig.10 As shown, a bottom electrode 210 , a piezoelectric layer 220 , and a top electrode 230 are deposited on the lateral circuit 116 and the sacrificial material 200 .

[0055] Step 4-3, such as Fig.11 As shown, the sacrificial material 200 is released, forming a cavity 201 .

[0056] In an optional embodiment, a support layer and a protection layer may be further deposited on the PMUT unit, or may not be deposited. In an optional embodiment, a support layer may be disposed on the side of the bottom electrode 210 that is not in contact with the piezoelectric layer 220 .

[0057] An embodiment of the present invention also relates to an electronic device, comprising the above-mentioned piezoelectric MEMS transducer device.

[0058] Based on the above, the present invention proposes the following technical solutions:

[0059] 1. A piezoelectric MEMS transducer device, comprising:

[0060] An external circuit and at least one piezoelectric MEMS transducer are stacked in a thickness direction of the transducer device,

[0061] in:

[0062] An electrical connection channel is provided between the piezoelectric MEMS transducer and the external circuit;

[0063] In a top view parallel to the thickness direction of the transducer device, the electrical connection channel at least partially overlaps with the piezoelectric MEMS transducer.

[0064] 2. The transducer device according to item 1, wherein:

[0065] In a top view parallel to the thickness direction of the transducer device, the electrical connection channel completely overlaps with the piezoelectric MEMS transducer.

[0066] 3. The transducer device according to item 1, wherein:

[0067] The at least one piezoelectric MEMS transducer includes a piezoelectric MEMS transducer array arranged in an array in a direction perpendicular to the thickness of the transducer device.

[0068] 4. The transducer device according to 3, wherein:

[0069] The at least one piezoelectric MEMS transducer array includes more than 5 piezoelectric MEMS transducer array elements.

[0070] 5. The transducer device according to any one of 1 to 4, wherein:

[0071] The piezoelectric MEMS transducer is a PMUT unit, and the external circuit includes a CMOS circuit.

[0072] 6. The transducer device according to 5, wherein:

[0073] The electrical connection channel includes a vertical circuit extending along the thickness direction of the transducer device and a lateral circuit extending perpendicular to the thickness direction of the transducer device.

[0074] 7. The transducer device according to 6, wherein:

[0075] The vertical circuit and the horizontal circuit are formed as a whole; or

[0076] There is a bonding interface between the vertical circuit and the horizontal circuit.

[0077] 8. The transducer device according to 6, wherein:

[0078] The PMUT cell includes a top electrode, a piezoelectric layer and a bottom electrode;

[0079] The CMOS circuit includes a first circuit and a second circuit adapted to be electrically connected to a top electrode and a bottom electrode, respectively. The electrical connection channel includes a first electrical connection channel electrically connecting the top electrode to the first circuit and a second electrical connection channel electrically connecting the bottom electrode to the second circuit, wherein a lateral circuit of the first electrical connection channel is electrically connected to the top electrode, and a lateral circuit of the second electrical connection channel is electrically connected to the bottom electrode.

[0080] 9. The transducer device according to 8, wherein:

[0081] The transducer device comprises a CMOS substrate and a protection layer arranged between the CMOS substrate and the PMUT unit, the vertical circuit is located in the protection layer, and the first circuit and the second circuit are at least partially located in the protection layer;

[0082] The part of the lateral circuit connected to the electrode of the PMUT unit is on the surface of the protective layer;

[0083] A cavity is provided between the PMUT unit and the lateral circuit in the thickness direction of the transducer device.

[0084] 10. The transducer device according to any one of 1 to 4, wherein:

[0085] The piezoelectric MEMS transducer includes a MEMS switch;

[0086] The external circuit includes a switch control circuit;

[0087] The electrical connection channel electrically connects the MEMS switch to a corresponding switch control circuit.

[0088] 11. The transducer device according to 10, wherein:

[0089] A MEMS switch substrate and a transfer layer are arranged between the MEMS switch and the switch control circuit in the thickness direction of the transducer device;

[0090] The electrical connection channel between the MEMS switch and the switch control circuit includes a first conductive via located in the MEMS switch, a second conductive via located in the MEMS switch substrate, and a third conductive via located in the transfer layer, which are electrically connected to each other, and the third conductive via is electrically connected to the switch control circuit;

[0091] In a top view parallel to the thickness direction of the transducer device, the first conductive via, the second conductive via, and the third conductive via at least partially overlap with the MEMS switch.

[0092] 12. The transducer device according to 10, wherein:

[0093] The electrical connection channel between the MEMS switch and the switch control circuit includes a first conductive via located in the MEMS switch and a second conductive via located in the MEMS switch substrate, which are electrically connected to each other, and the second conductive via is electrically connected to the switch control circuit;

[0094] In a top view parallel to the thickness direction of the transducer device, the first conductive via, the second conductive via, and the MEMS switch at least partially overlap.

[0095] 13. The transducer device according to any one of 1 to 4, wherein:

[0096] The piezoelectric MEMS transducer includes a MEMS resonator, and the MEMS resonator includes a substrate, a bottom electrode, a piezoelectric layer and a top electrode;

[0097] The external circuit is electrically connected to the bottom electrode via an electrical connection path, which includes a conductive through-hole passing through the substrate.

[0098] 14. The transducer device according to 13, wherein:

[0099] The at least one piezoelectric MEMS transducer includes a first MEMS resonator and a second MEMS resonator arranged adjacent to each other in a laterally direction, a bottom electrode of the first MEMS resonator is electrically connected to a top electrode of the second MEMS resonator, and the bottom electrode of the first MEMS resonator is electrically connected to an external circuit via the conductive through hole passing through the substrate.

[0100] 15. The transducer device according to 13, wherein:

[0101] The transducer device is a MEMS oscillator.

[0102] 16. The transducer device according to 13, wherein:

[0103] The bottom electrode of the MEMS resonator is a gap electrode, and the conductive through hole passing through the substrate is electrically connected to the gap electrode.

[0104] 17. The transducer device according to any one of 1 to 4, wherein:

[0105] The at least one piezoelectric MEMS transducer comprises a plurality of MEMS inkjet actuators arranged on a substrate;

[0106] The external circuit is electrically connected to the corresponding MEMS inkjet execution unit via an electrical connection channel, and the electrical connection channel is a conductive through hole passing through the substrate.

[0107] 18. The transducer device according to any one of 1 to 4, wherein:

[0108] The at least one piezoelectric MEMS transducer includes a MEMS speaker or a MEMS micromirror.

[0109] 19. The transducer device according to any one of 1 to 4, wherein:

[0110] The electrical connection channel includes a conductive through hole.

[0111] 20. The transducer device according to any one of 1 to 4, wherein:

[0112] The external circuit includes a CMOS circuit, a substrate, a PCB, a MEMS device or a transfer layer.

[0113] 21. A method for manufacturing a piezoelectric MEMS transducer device, comprising the steps of:

[0114] Provide external circuits;

[0115] An electrical connection channel including a horizontal circuit and a vertical circuit is formed above the external circuit, wherein the vertical circuit is electrically connected to the external circuit;

[0116] forming a MEMS transducer, wherein the MEMS transducer is electrically connected to the lateral circuit,

[0117] in:

[0118] The method further comprises the step of causing the electrical connection channel to at least partially overlap the MEMS transducer in a top view parallel to the thickness direction of the transducer device.

[0119] 22. The method according to 21, wherein:

[0120] The MEMS transducer comprises a PMUT unit, wherein the PMUT unit comprises a top electrode, a piezoelectric layer and a bottom electrode;

[0121] The step of providing an external circuit includes: providing a CMOS substrate, wherein a protective layer is disposed on the surface of the CMOS substrate, and an electrical connection portion is disposed in the protective layer;

[0122] The method further comprises the steps of:

[0123] etching the protective layer to expose the electrical connection portion;

[0124] Depositing the electrical connection channel including a horizontal circuit and a vertical circuit on the protective layer, wherein the vertical circuit is electrically connected to the electrical connection portion;

[0125] forming the PMUT unit on the protective layer;

[0126] The electrical connection portion includes a first circuit and a second circuit adapted to be electrically connected to a top electrode and a bottom electrode respectively, and the method includes electrically connecting the top electrode to one lateral circuit and electrically connecting the bottom electrode to another lateral circuit.

[0127] 23. The method according to 22, wherein the step of depositing a lateral circuit and a vertical circuit on the protective layer comprises:

[0128] forming the horizontal circuit and the vertical circuit respectively; or

[0129] The horizontal circuit and the vertical circuit are formed at one time.

[0130] 24. An electronic device comprising the piezoelectric MEMS transducer device according to any one of 1 to 20 or the piezoelectric MEMS transducer device manufactured according to any one of 21 to 23.

[0131] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A piezoelectric MEMS transducer device, comprising: An external circuit and at least one piezoelectric MEMS transducer are stacked in a thickness direction of the transducer device, in: An electrical connection channel is provided between the piezoelectric MEMS transducer and the external circuit; In a top view parallel to the thickness direction of the transducer device, the electrical connection channel at least partially overlaps with the corresponding piezoelectric MEMS transducer.

2. The transducer device according to claim 1, wherein: In a top view parallel to the thickness direction of the transducer device, the electrical connection channels all overlap with the corresponding piezoelectric MEMS transducers.

3. The transducer device according to claim 1, wherein: The at least one piezoelectric MEMS transducer includes a piezoelectric MEMS transducer array arranged in an array in a direction perpendicular to the thickness of the transducer device.

4. The transducer device according to claim 3, wherein: The at least one piezoelectric MEMS transducer array includes more than 5 piezoelectric MEMS transducer array elements.

5. The transducer device according to any one of claims 1 to 4, wherein: The piezoelectric MEMS transducer is a PMUT unit, and the external circuit includes a CMOS circuit.

6. The transducer device according to claim 5, wherein: The electrical connection channel includes a vertical circuit extending along the thickness direction of the transducer device and a lateral circuit extending perpendicular to the thickness direction of the transducer device.

7. The transducer device according to claim 6, wherein: The vertical circuit and the horizontal circuit are formed as a whole; or There is a bonding interface between the vertical circuit and the horizontal circuit.

8. The transducer device according to claim 6, wherein: The PMUT cell includes a top electrode, a piezoelectric layer and a bottom electrode; The CMOS circuit includes a first circuit and a second circuit adapted to be electrically connected to a top electrode and a bottom electrode, respectively. The electrical connection channel includes a first electrical connection channel electrically connecting the top electrode to the first circuit and a second electrical connection channel electrically connecting the bottom electrode to the second circuit, wherein a lateral circuit of the first electrical connection channel is electrically connected to the top electrode, and a lateral circuit of the second electrical connection channel is electrically connected to the bottom electrode.

9. The transducer device according to claim 8, wherein: The transducer device comprises a CMOS substrate and a protection layer arranged between the CMOS substrate and the PMUT unit, the vertical circuit is located in the protection layer, and the first circuit and the second circuit are at least partially located in the protection layer; The part of the lateral circuit connected to the electrode of the PMUT unit is on the surface of the protective layer; A cavity is provided between the PMUT unit and the lateral circuit in the thickness direction of the transducer device.

10. The transducer device according to any one of claims 1 to 4, wherein: The piezoelectric MEMS transducer includes a MEMS switch; The external circuit includes a switch control circuit; The electrical connection channel electrically connects the MEMS switch to a corresponding switch control circuit.

11. The transducer device according to claim 10, wherein: A MEMS switch substrate and a transfer layer are arranged between the MEMS switch and the switch control circuit in the thickness direction of the transducer device; The electrical connection channel between the MEMS switch and the switch control circuit includes a first conductive via located in the MEMS switch, a second conductive via located in the MEMS switch substrate, and a third conductive via located in the transfer layer, which are electrically connected to each other, and the third conductive via is electrically connected to the switch control circuit; In a top view parallel to the thickness direction of the transducer device, the first conductive via, the second conductive via, and the third conductive via at least partially overlap with the MEMS switch.

12. The transducer device according to claim 10, wherein: The electrical connection channel between the MEMS switch and the switch control circuit includes a first conductive via located in the MEMS switch and a second conductive via located in the MEMS switch substrate, which are electrically connected to each other, and the second conductive via is electrically connected to the switch control circuit; In a top view parallel to the thickness direction of the transducer device, the first conductive via, the second conductive via, and the MEMS switch at least partially overlap.

13. The transducer device according to any one of claims 1 to 4, wherein: The piezoelectric MEMS transducer includes a MEMS resonator, and the MEMS resonator includes a substrate, a bottom electrode, a piezoelectric layer and a top electrode; The external circuit is electrically connected to the bottom electrode via an electrical connection path, which includes a conductive through-hole passing through the substrate.

14. The transducer device according to claim 13, wherein: The at least one piezoelectric MEMS transducer includes a first MEMS resonator and a second MEMS resonator arranged adjacent to each other in a laterally direction, a bottom electrode of the first MEMS resonator is electrically connected to a top electrode of the second MEMS resonator, and the bottom electrode of the first MEMS resonator is electrically connected to an external circuit via the conductive through hole passing through the substrate.

15. The transducer device of claim 13, wherein: The transducer device is a MEMS oscillator.

16. The transducer device of claim 13, wherein: The bottom electrode of the MEMS resonator is a gap electrode, and the conductive through hole passing through the substrate is electrically connected to the gap electrode.

17. The transducer device according to any one of claims 1 to 4, wherein: The at least one piezoelectric MEMS transducer comprises a plurality of MEMS inkjet actuators arranged on a substrate; The external circuit is electrically connected to the corresponding MEMS inkjet execution unit via an electrical connection channel, and the electrical connection channel is a conductive through hole passing through the substrate.

18. The transducer device according to any one of claims 1 to 4, wherein: The at least one piezoelectric MEMS transducer includes a MEMS speaker or a MEMS micromirror.

19. The transducer device according to any one of claims 1 to 4, wherein: The electrical connection channel includes a conductive through hole.

20. The transducer device according to any one of claims 1 to 4, wherein: The external circuit includes a CMOS circuit, a substrate, a PCB, a MEMS device or a transfer layer.

21. A method for manufacturing a piezoelectric MEMS transducer device, comprising the steps of: Provide external circuits; An electrical connection channel including a horizontal circuit and a vertical circuit is formed above the external circuit, wherein: The vertical circuit is electrically connected to the external circuit; forming a MEMS transducer, wherein the MEMS transducer is electrically connected to the lateral circuit, in: The method further comprises the step of: making the electrical connection channel at least partially overlap with the corresponding MEMS transducer in a top view parallel to the thickness direction of the transducer device.

22. The method of claim 21, wherein: The MEMS transducer comprises a PMUT unit, wherein the PMUT unit comprises a top electrode, a piezoelectric layer and a bottom electrode; The step of providing an external circuit includes: providing a CMOS substrate, wherein a protective layer is disposed on the surface of the CMOS substrate, and an electrical connection portion is disposed in the protective layer; The method further comprises the steps of: etching the protective layer to expose the electrical connection portion; Depositing the electrical connection channel including a horizontal circuit and a vertical circuit on the protective layer, wherein the vertical circuit is electrically connected to the electrical connection portion; forming the PMUT unit on the protective layer; The electrical connection portion includes a first circuit and a second circuit adapted to be electrically connected to a top electrode and a bottom electrode respectively, and the method includes electrically connecting the top electrode to one lateral circuit and electrically connecting the bottom electrode to another lateral circuit.

23. The method according to claim 22, wherein: The step of depositing a lateral circuit and a vertical circuit on the protective layer comprises: forming the horizontal circuit and the vertical circuit respectively; or The horizontal circuit and the vertical circuit are formed at one time.

24. An electronic device comprising the piezoelectric MEMS transducer device according to any one of claims 1 to 20 or the piezoelectric MEMS transducer device manufactured by the method according to any one of claims 21 to 23.

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