MEMS device and forming method thereof, and electronic equipment

Abstract

The invention discloses an MEMS device, a forming method thereof and electronic equipment. The MEMS device comprises: a control circuit structure, wherein the control circuit structure comprises a first substrate and a circuit wiring layer which is arranged on the first substrate and is provided with a first connecting end; the MEMS device structure and the control circuit structure are arranged in a stacked mode, the MEMS device structure comprises an MEMS structure, and the MEMS structure is provided with a second connecting end which is bonded and electrically connected with the first connecting end; the conductive through hole structure is located in the MEMS device structure and electrically connected with the second connecting end and the first connecting end, and the conductive through hole structure is located in the MEMS device structure, so that the parasitic capacitance of the control circuit structure is reduced, the processing precision of a control circuit of the control circuit structure is improved, and the measurement precision of the MEMS device is improved; the size and the process window of the conductive through hole structure can be increased, and the probability of poor electric connection between the control circuit structure and the MEMS device structure can be reduced.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of semiconductor manufacturing, and in particular to a MEMS device, a forming method thereof, and an electronic device. BACKGROUND

[0002] Micro-Electro-Mechanical System (MEMS) is based on microelectronics, micro-mechanics and material science, and studies, designs, manufactures and has specific functions of micro devices. Micro-Electro-Mechanical System is a strategic high-tech field of cross-disciplinary integration, and is one of the leading industries in the future.

[0003] A finished MEMS device is usually composed of two chips, one is a micro-mechanical chip, that is, a MEMS chip, and the other is a special integrated circuit chip for controlling the MEMS chip, that is, an ASIC chip. The two chips can be independent, combined together by a conventional electronic packaging method such as mounting, wire bonding and encapsulation to become a finished MEMS device. The MEMS chip can also be integrated with the ASIC chip in a wafer processing process through wafer-level packaging to become a monolithic integrated MEMS chip, and then a conventional packaging is performed to form a finished MEMS device. In the monolithic integrated MEMS chip, the MEMS chip and the ASIC chip are tightly attached face to face, the signal channel is short, and the influence of external environment interference signals is small, so the original signal of the MEMS chip can be designed to be small, thereby reducing the chip area and the chip cost.

[0004] However, the performance of the monolithic integrated MEMS chip still needs to be improved. SUMMARY

[0005] Embodiments of the present application solve the problem of providing a MEMS device, a forming method thereof, and an electronic device to improve the performance of the MEMS device.

[0006] To solve the above problem, embodiments of the present application provide a MEMS device, comprising: a control circuit structure, the control circuit structure comprising a first substrate and a circuit wiring layer on the first substrate, the circuit wiring layer having a first connection end; a MEMS device structure stacked with the control circuit structure, the MEMS device structure comprising a MEMS structure, the MEMS structure having a second connection end, the second connection end being bonded and electrically connected with the first connection end; and a conductive via structure in the MEMS device structure, one end of the conductive via structure facing the control circuit structure being electrically connected with the second connection end and the first connection end, and the other end of the conductive via structure facing away from the control circuit structure being exposed by the MEMS device structure.

[0007] Accordingly, the embodiments of the present application also provide a method for forming a MEMS device, comprising: providing a control circuit structure, the control circuit structure comprising a first substrate, and a circuit wiring layer on the first substrate, the circuit wiring layer having a first connecting end; providing a MEMS device structure, the MEMS device structure comprising a MEMS structure, the MEMS structure having a second connecting end; facing a side of the MEMS device structure having the second connecting end to a side of the control circuit structure having the first connecting end, and bonding the first connecting end and the second connecting end to make the first connecting end and the second connecting end electrically connected; and forming a conductive via structure in the MEMS device structure, one end of the conductive via structure being electrically connected to the second connecting end and the first connecting end, and the other end of the conductive via structure being exposed by the MEMS device structure.

[0008] Compared with the prior art, the technical scheme of the embodiments of the present application has the following advantages:

[0009] The MEMS device provided by the application comprises a control circuit structure, the control circuit structure comprises a first substrate and a circuit wiring layer on the first substrate, the circuit wiring layer has a first connecting end, a MEMS device structure stacked with the control circuit structure, the MEMS device structure comprises a MEMS structure, the MEMS structure has a second connecting end, the second connecting end is bonded and electrically connected with the first connecting end, a conductive via structure in the MEMS device structure, one end of the conductive via structure facing the control circuit structure is electrically connected with the second connecting end and the first connecting end, and the other end of the conductive via structure away from the control circuit structure is exposed by the MEMS device structure. The conductive via structure in the MEMS device structure avoids the conductive via structure in the control circuit structure, and accordingly avoids the increase of the parasitic capacitance of the control circuit structure caused by the conductive via structure in the control circuit structure, thereby facilitating the reduction of the parasitic capacitance of the control circuit structure, the improvement of the processing precision of the control circuit in the control circuit structure, and the improvement of the measurement precision of the MEMS device. Moreover, compared with the control circuit structure, the internal structure of the MEMS device structure is relatively simple, the conductive via structure is arranged in the MEMS device structure, thereby facilitating the increase of the size of the conductive via structure, the increase of the process window of the conductive via structure, the reduction of the process difficulty of forming the conductive via structure, and the reduction of the probability of poor electrical connection between the control circuit structure and the MEMS device structure after bonding caused by the small size of the conductive via structure and overlay shift, thereby facilitating the reduction of the probability of failure of the MEMS device. Therefore, the technical scheme of the application facilitates the improvement of the yield and electrical performance of the MEMS device.

[0010] The forming method of the MEMS device provided by the embodiment of the present application comprises the following steps: providing a control circuit structure, wherein the control circuit structure comprises a first substrate and a circuit wiring layer on the first substrate, and the circuit wiring layer is provided with a first connecting end; providing a MEMS device structure, wherein the MEMS device structure comprises a MEMS structure, and the MEMS structure is provided with a second connecting end; bonding the first connecting end and the second connecting end, so that the first connecting end and the second connecting end are electrically connected; and forming a conductive via structure in the MEMS device structure, wherein one end of the conductive via structure is electrically connected with the second connecting end and the first connecting end, and the other end of the conductive via structure is exposed by the MEMS device structure. The conductive via structure is arranged in the MEMS device structure, so that the conductive via structure is not arranged in the control circuit structure, and the parasitic capacitance of the control circuit structure is reduced, the processing precision of the control circuit in the control circuit structure is improved, and the measurement precision of the MEMS device is improved. In addition, compared with the control circuit structure, the internal structure of the MEMS device structure is relatively simple, the conductive via structure is arranged in the MEMS device structure, so that the size of the conductive via structure is increased, the process window of the conductive via structure is increased, the process difficulty of forming the conductive via structure is reduced, the probability of poor electrical connection between the control circuit structure and the MEMS device structure after bonding due to the small size of the conductive via structure and overlay shift is reduced, and the probability of failure of the MEMS device is reduced. Therefore, the technical scheme of the present application is beneficial to improving the yield and electrical performance of the MEMS device. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a top view structural schematic diagram of a first embodiment of the MEMS device of the present application;

[0012] Figure 2 is Figure 1 is a sectional view structural schematic diagram at AA1;

[0013] Figure 3 is a sectional view structural schematic diagram of a second embodiment of the MEMS device of the present application;

[0014] Figures 4 to 17 is a structural schematic diagram corresponding to each step in a first embodiment of the forming method of the MEMS device of the present application;

[0015] Figure 18is a structural schematic diagram corresponding to each step in a second embodiment of a method for forming a MEMS device of the present application. DETAILED DESCRIPTION

[0016] In the prior art, since the control circuit structure is generally used to process the electrical signals obtained by the MEMS device structure, the control circuit structure generally has a complex internal structure, for example, a plurality of circuit wiring layers arranged in a stack, and the conductive via structure is generally arranged in the control circuit structure with a complex internal structure, which easily increases the parasitic capacitance of the control circuit structure, thereby easily affecting the processing accuracy of the control circuit. In addition, since the control circuit structure has a complex internal structure, the space available for arranging the conductive via structure is often small, which accordingly easily makes the size of the arranged conductive via structure small, thereby making the process window for forming the conductive via structure small, and accordingly making the process for forming the conductive via structure difficult. Moreover, due to the small size of the conductive via structure and overlay shift, the electrical connection between the control circuit structure and the MEMS device structure is easily not good, which further easily leads to failure of the MEMS device.

[0017] To solve the above technical problems, an embodiment of the present application provides a MEMS device, comprising: a control circuit structure, the control circuit structure comprising a first substrate and a circuit wiring layer on the first substrate, the circuit wiring layer having a first connecting end; a MEMS device structure stacked with the control circuit structure, the MEMS device structure comprising a MEMS structure, the MEMS structure having a second connecting end, the second connecting end being bonded and electrically connected with the first connecting end; and a conductive via structure in the MEMS device structure, one end of the conductive via structure facing the control circuit structure being electrically connected with the second connecting end and the first connecting end, and the other end of the conductive via structure facing away from the control circuit structure being exposed by the MEMS device structure.

[0018] The scheme of the embodiment of the present application comprises: a control circuit structure, which comprises a first substrate, and a circuit wiring layer on the first substrate, the circuit wiring layer having a first connecting end; a MEMS device structure stacked with the control circuit structure, the MEMS device structure comprising a MEMS structure, the MEMS structure having a second connecting end, the second connecting end being bonded and electrically connected with the first connecting end; and a conductive via structure in the MEMS device structure, one end of the conductive via structure facing the control circuit structure being electrically connected with the second connecting end and the first connecting end, and the other end of the conductive via structure being exposed by the MEMS device structure. The conductive via structure is in the MEMS device structure, avoiding the arrangement of the conductive via structure in the control circuit structure, and accordingly avoiding the increase of the parasitic capacitance of the control circuit structure caused by the arrangement of the conductive via structure in the control circuit structure, thereby facilitating the reduction of the parasitic capacitance in the control circuit structure, the improvement of the processing precision of the control circuit in the control circuit structure, and the improvement of the measurement precision of the MEMS device. Moreover, compared with the control circuit structure, the internal structure of the MEMS device structure is relatively simple, and the arrangement of the conductive via structure in the MEMS device structure facilitates the increase of the size of the conductive via structure, thereby facilitating the increase of the process window of the conductive via structure, the reduction of the process difficulty of forming the conductive via structure, and the reduction of the probability of poor electrical connection between the control circuit structure and the MEMS device structure after bonding caused by the small size of the conductive via structure and overlay shift, and thereby the reduction of the probability of failure of the MEMS device. Therefore, the technical scheme of the present application facilitates the improvement of the yield and electrical performance of the MEMS device.

[0019] In order to make the above objectives, features and advantages of the embodiments of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0020] Figure 1 is a schematic view of a top structure of a first embodiment of the MEMS device of the present application, Figure 2 is Figure 1 is a sectional view at AA1.

[0021] Reference is made to Figures 1 to 2In the embodiment, the MEMS device comprises a control circuit structure 110, the control circuit structure 110 comprises a first substrate 111 and a circuit wiring layer 112 on the first substrate 111, the circuit wiring layer 112 has a first connecting end 115; a MEMS device structure 120 stacked with the control circuit structure 110, the MEMS device structure 120 comprises a MEMS structure 121, the MEMS structure 121 has a second connecting end 125, the second connecting end 125 is bonded and electrically connected with the first connecting end 115; a conductive via structure 130 in the MEMS device structure 120, one end of the conductive via structure 130 towards the control circuit structure 110 is electrically connected with the second connecting end 125 and the first connecting end 115, and the other end of the conductive via structure 130 away from the control circuit structure 110 is exposed by the MEMS device structure 120.

[0022] It should be noted that, in order to clearly show the structure of the MEMS device, Figure 1 In the embodiment, the re-wiring layer is simplified, and the second insulating layer and part of the second conductive layer on top of the conductive via structure are omitted.

[0023] The control circuit structure 110 is used for processing the electrical signal obtained by the MEMS device structure 120.

[0024] In the embodiment, the control circuit structure 110 has a first surface 1101.

[0025] As an example, the control circuit structure 110 is an ASIC (Application Specific Integrated Circuit) chip. In other embodiments, the control circuit structure can also be other chips with control circuits.

[0026] The ASIC chip has complete integrated circuit functions, can process the electrical signal input from the MEMS device structure 120, and output the signal required by the end user, or input the electrical signal to the MEMS device structure 120 in reverse, to control the movement of the MEMS device structure 120.

[0027] The first substrate 111 is used to provide a process basis for forming the control circuit structure 110.

[0028] In the embodiment, the material of the first substrate 111 comprises silicon. In other embodiments, the material of the first substrate can also be germanium, silicon germanium, silicon carbide, gallium arsenide or indium gallium, or other materials, and the substrate can also be a silicon-on-insulator substrate or a germanium-on-insulator substrate, or other types of substrates.

[0029] The circuit wiring layer 112 is used to realize the transmission of electrical signals, for example, to connect the various components (e.g., transistors, etc.) of the control circuit structure 110 to each other to form a complete circuit to realize the transmission of electrical signals.

[0030] The first connecting end 115 is used to be bonded and electrically connected with the second connecting end 125 to realize the transmission of electrical signals between the control circuit structure 110 and the MEMS device structure 120.

[0031] In this embodiment, the material of the first connecting end 115 includes silicon, aluminum, germanium, tin, or gold.

[0032] Silicon, aluminum, germanium, tin, and gold are easy to realize a lower bonding temperature, which reduces the probability of affecting the measurement accuracy of the MEMS device due to excessive stress caused by a high bonding temperature, for example, affecting the measurement accuracy due to deformation inside the MEMS device caused by a high bonding temperature. Moreover, reducing the bonding temperature also helps to reduce the probability of affecting the components inside the control circuit structure 110 caused by the bonding process.

[0033] Specifically, the material of the first connecting end 115 includes aluminum.

[0034] Aluminum has good electrical conductivity and ductility, and is low in cost. Therefore, it is beneficial to reduce the cost of the first connecting end 115 under the condition of low temperature and small resistance between the first connecting end 115 and the second connecting end 125.

[0035] In other embodiments, the material of the first connecting end can also include silicon, germanium, tin, or gold. In other embodiments, the material of the first connecting end can also include other conductive materials that can realize a lower bonding temperature.

[0036] In this embodiment, the control circuit structure 110 further includes an interconnection layer located on the circuit wiring layer 112 and electrically connected with the circuit wiring layer 112, and the interconnection layer serves as the first connecting end 115.

[0037] In this embodiment, the first connecting end 115 is located on the first surface 1101.

[0038] The MEMS (Micro-Electro-Mechanical System) device structure 120 is used to directly perceive the change of external physical quantities (e.g., acceleration, pressure, etc.) through the micro-mechanical structure inside it, and convert the change of external physical quantities into electrical signals such as capacitance.

[0039] In this embodiment, the MEMS device structure 120 has a second surface 1202 and a third surface 1203 disposed opposite to each other; the second surface 1202 faces the first surface 1101 .

[0040] As an example, the material of the MEMS structure 121 includes silicon. In other embodiments, the material of the MEMS structure may also be other materials such as silicon germanium, silicon carbide, gallium arsenide, or indium gallium.

[0041] In this embodiment, the MEMS device structure 120 further includes: a cap structure 122, which is stacked and bonded with the MEMS structure 121, and a groove 126 (such as Figure 2 As shown); the MEMS structure 121 has a second connection end 125 on the side facing away from the cap structure 122, and along a direction parallel to the top surface of the MEMS structure 121, the MEMS structure 121 includes a support portion 123 and a vibration portion 124 located between adjacent support portions 123, and the vibration portion 124 is located in a cavity surrounded by the groove 126, the support portion 123, and the control circuit structure 110.

[0042] The cap structure 122 is used to protect the MEMS structure 121 .

[0043] The groove 126 is used to enclose a cavity together with the support portion 123 and the control circuit structure 110 , thereby providing a space for the vibration portion 124 located in the cavity to move freely.

[0044] The supporting portion 123 is used to provide support for the vibrating portion 124 .

[0045] The vibration part 124 is used to directly sense changes in external physical quantities, and, through cooperation with the support part 123 , convert the changes in external physical quantities into electrical signals that can be processed by the control circuit structure 110 .

[0046] The surface of the MEMS structure 121 having the second connection end 125 is the second surface 1202 , and the second connection end 125 is located on the second surface 1202 ; the surface of the MEMS structure 121 facing the cap structure 122 is the third surface 1203 .

[0047] It should be noted that the MEMS structure 121 is electrically isolated from the cap structure 122 .

[0048] In this embodiment, the support portion 123 includes a first protruding block 1231 protruding from the vibrating portion 124, and a first conductive layer covering the first protruding block 1231, the first conductive layer serving as the second connecting end 125. The material of the first conductive layer is different from that of the first protruding block 1231, so that a conductive material which is easy to realize a lower bonding temperature and is low in price can be selected as the material of the first conductive layer, thereby reducing the process cost of the MEMS device.

[0049] The first protruding block 1231 is configured to provide a gap between the vibrating portion 124 and the first connecting end 115, so as to ensure that the vibrating portion 124 has a space for up-and-down vibration.

[0050] As an example, the lateral dimension of the first protruding block 1231 is greater than that of the conductive via structure 130. Compared with the conductive via structure 130, the first protruding block 1231 has a larger lateral dimension, which is conducive to maintaining the structural integrity of the first protruding block 1231 and the first conductive layer during the formation of the conductive via structure 130, so that the electrical connection between the second connecting end 125 and the first connecting end 115 is better.

[0051] In other embodiments, the support portion includes a first protruding block protruding from the vibrating portion, the first protruding block serving as the second connecting end, which is conducive to reducing the process steps.

[0052] The second connecting end 125 is configured to be bonded and electrically connected with the first connecting end 115, so as to realize the transmission of electrical signals between the MEMS device structure 120 and the control circuit structure 110.

[0053] In this embodiment, the material of the second connecting end 125 includes germanium, aluminum, tin or gold. Aluminum, germanium, tin and gold are easy to realize a lower bonding temperature.

[0054] As an example, the material of the second connecting end 125 is different from that of the first connecting end 115. As another example, the material of the second connecting end can also be the same as that of the first connecting end. That is, the material which can realize a lower bonding temperature when the second connecting end is bonded with the first connecting end can be used as the material of the second connecting end and the first connecting end.

[0055] In particular, the material of the second connecting end 125 includes germanium.

[0056] Germanium is a commonly used material in semiconductor processes, which is conducive to reducing the process cost of the second connecting end 125. Moreover, in the case that the material of the first connecting end 115 comprises aluminum, the material of the second connecting end 125 comprises germanium, which is conducive to achieving a lower bonding temperature.

[0057] In other embodiments, the material of the second connecting end can also comprise aluminum, tin or gold. In other embodiments, the material of the second connecting end can also comprise other conductive materials capable of achieving a lower bonding temperature.

[0058] In this embodiment, the cap structure 122 comprises a third substrate 127 and a bonding layer 128 located on the third substrate 127, and the bonding layer 128 is bonded to the side of the MEMS structure 121 opposite to the second connecting end 125, i.e., the bonding layer is bonded to the third side 1203 of the MEMS structure.

[0059] The third substrate 127 is used to provide a process basis for forming the cap structure 122.

[0060] As an example, the material of the third substrate 127 comprises silicon. In other embodiments, the material of the third substrate can also be germanium, silicon germanium, silicon carbide, gallium arsenide or other materials such as indium gallium.

[0061] The bonding layer 128 is used to be bonded to the side of the MEMS structure 121 opposite to the second connecting end 125, so that the third substrate 127 is stacked with the MEMS structure 121.

[0062] Specifically, the material of the bonding layer 128 is an insulating material. The bonding layer 128 serves as a first insulating layer and is used to electrically isolate the third substrate 127 from the MEMS structure 121, i.e., the cap structure 122 is electrically isolated from the MEMS structure 121. More specifically, the material of the bonding layer 128 comprises silicon oxide. In other embodiments, the material of the bonding layer can also be other insulating materials.

[0063] In other embodiments, the bonding layer can also be used to be bonded only to the side of the MEMS structure opposite to the second connecting end.

[0064] It should be noted that the side of the cap structure 122 facing the MEMS structure 121 is provided with a groove 126, i.e., the side of the cap structure 122 facing the third side 1203 is provided with a groove 126; the bonding layer 128 also covers the inner wall of the groove 126, i.e., the bonding layer 128 conformally covers the third substrate 127.

[0065] The bonding layer 128 is used to protect the groove 126, which is conducive to reducing the probability of damage to the third substrate 127 in the process of forming the MEMS structure 121. Moreover, the bonding layer 128 conformally covers the third substrate 127, which is also conducive to reducing the difficulty of forming the bonding layer 128.

[0066] The conductive via structure 130 is used to be electrically connected with an external circuit.

[0067] The conductive via structure 130 is located in the MEMS device structure 120, which avoids setting the conductive via structure 130 in the control circuit structure 110, and accordingly avoids increasing the parasitic capacitance of the control circuit structure due to setting the conductive via structure in the control circuit structure, thereby being conducive to reducing the parasitic capacitance in the control circuit structure 110, improving the processing precision of the control circuit in the control circuit structure 110, and further being conducive to improving the measurement precision of the MEMS device. Moreover, compared with the control circuit structure 110, the internal structure of the MEMS device structure 120 is relatively simple, and setting the conductive via structure 130 in the MEMS device structure 120 is conducive to increasing the size of the conductive via structure 130, thereby being conducive to increasing the process window of the conductive via structure 130, reducing the process difficulty of forming the conductive via structure 130, and reducing the probability of poor electrical connection between the control circuit structure 110 and the MEMS device structure 120 after bonding due to the small size of the conductive via structure 130 and overlay shift, and further being conducive to reducing the probability of failure of the MEMS device. Therefore, the technical scheme of the present application is conducive to improving the yield and electrical performance of the MEMS device.

[0068] In the embodiment, the conductive via structure 130 penetrates the MEMS device structure 120, that is, the conductive via structure 130 penetrates the cap structure 122 and the MEMS structure 121, that is, the MEMS device structure 120 exposes two ends of the conductive via structure 130.

[0069] The conductive via structure 130 penetrates the MEMS device structure 120, which is conducive to reducing the difficulty of forming the conductive via structure 130.

[0070] In other embodiments, the conductive via structure can also be located in the partial thickness of the MEMS device structure, for example, the conductive via structure penetrates through the cap structure, the cap structure exposes one end of the conductive via structure away from the control circuit structure, and the conductive via structure is located in the partial thickness of the MEMS structure, one end of the conductive via structure towards the control circuit structure is in contact with and electrically connected to the first conductive layer. In yet other embodiments, one end of the conductive via structure towards the control circuit structure can also not be in contact with the first conductive layer, i.e., the conductive via structure is only electrically connected to the first conductive layer.

[0071] In this embodiment, the conductive via structure 130 is located at the edge of the MEMS device structure 120, which is advantageous to reduce the modification to the existing MEMS device structure 120 while further increasing the size of the conductive via structure 130. In other embodiments, the conductive via structure can also be located at other positions of the MEMS device structure.

[0072] Specifically, the number of the conductive via structures 130 is multiple; the MEMS device further comprises: multiple redistribution layers (RDL) 140 located on the side of the cap structure 122 away from the MEMS structure 121, each of the redistribution layers 140 is electrically connected to the corresponding conductive via structure 130; and second bumps 141 located on the redistribution layers 140, each of the second bumps 141 located on different redistribution layers 140 is staggered.

[0073] The redistribution layer (RDL) 140 is used to provide a process platform for the second bump 141, and is used to redistribute the connection end of the conductive via structure 130, so that the layout of the connection end of the redistributed conductive via structure 130 meets the process requirement.

[0074] The second bump 141 is used to connect with an external circuit, so that the conductive via structure 130 is electrically connected to the external circuit. Moreover, each of the second bumps 141 located on different redistribution layers 140 is staggered, which is advantageous to reduce the probability of contact between adjacent second bumps 141.

[0075] As an example, the second bump 141 is a solder ball. The material of the solder ball can be tin or other suitable materials.

[0076] More specifically, the MEMS device further includes a second insulating layer 142 on sidewalls of a via (not labeled) for accommodating the conductive via structure 130, the second insulating layer 142 also covers a surface on a side of the cap structure 122 facing away from the MEMS structure 121; the conductive via structure 130 includes a second conductive layer 132 in the via, the second conductive layer 132 also on the second insulating layer 142 in a region outside the conductive via structure 130, the second conductive layer 132 outside the conductive via structure 130 serving as a re-routed layer 140.

[0077] The second insulating layer 142 is on sidewalls of a via for accommodating the conductive via structure 130, facilitating electrically isolating the conductive via structure 130 from the rest of the MEMS device structure 120 except the second connection terminal 125. In other embodiments, the MEMS device can also not include the second insulating layer in a case where a material in a region of the MEMS device structure penetrated by the conductive via structure is an insulating material.

[0078] The second insulating layer 142 also covers a surface on a side of the cap structure 122 facing away from the MEMS structure 121, for electrically isolating the re-routed layer 140 from the cap structure 122. In yet other embodiments, other ways can also be used to electrically isolate the re-routed layer from the cap structure.

[0079] As an example, the second insulating layer 142 is of silicon oxide. In other embodiments, the second insulating layer can also be of other insulating materials.

[0080] The second conductive layer 132 in the via serves as the conductive via structure 130.

[0081] The second conductive layer 132 is also on the second insulating layer 142 in a region outside the conductive via structure 130, facilitating simplifying a step of forming the re-routed layer 140.

[0082] It is noted that the second conductive layer 132 is of copper. In other embodiments, the second conductive layer can also be of other conductive materials.

[0083] It is further noted that the thickness of the re-routed layer 140 should not be too small or too large. Too small or too large thickness of the re-routed layer 140 can both increase difficulty in forming the re-routed layer 140. Therefore, in the present embodiment, the thickness of the re-routed layer 140 is in a range of 0.1 micrometers to 10 micrometers.

[0084] As an example, the conductive via structure 130 further comprises an adhesion layer 131 between the second conductive layer 132 and the second insulating layer 142.

[0085] The adhesion layer 131 is configured to improve the adhesion between the second conductive layer 132 and the second insulating layer 142.

[0086] The application further provides a MEMS device of a second embodiment. Figure 3 is a schematic diagram of a cross-sectional structure of a MEMS device of a second embodiment of the application.

[0087] The second embodiment is the same as the first embodiment, and thus the same parts are not described again. The second embodiment is different from the first embodiment in that, referring to Figure 3 , the MEMS device structure further comprises a third bump 243 on the top of the conductive via structure 230 and electrically connected with the conductive via structure 230.

[0088] The third bump 243 is on the top of the conductive via structure 230 and electrically connected with the conductive via structure 230, which is configured to simplify the complexity of the circuit on the side of the cap structure 222 away from the MEMS structure 221, thereby simplifying the process flow of the MEMS device.

[0089] It can be understood that the third bump 243 is on the top of the conductive via structure 230 and electrically connected with the conductive via structure 230, and accordingly, the second conductive layer 232 is only in the via (not labeled) for accommodating the conductive via structure 230, thereby facilitating the difficulty of forming the second conductive layer 232.

[0090] It should be noted that the third bump 243 comprises a solder pad 2431 on the top of the conductive via structure 230 and electrically connected with the conductive via structure 230, and a solder ball 2432 on the solder pad 2431, and the solder ball 2432 is electrically connected with the solder pad 2431. In other embodiments, the third bump can only comprise a solder pad.

[0091] The material of the solder pad 2431 comprises aluminum. The metal conductivity of aluminum is better, and the resistance is smaller, which is configured to obtain a solder pad 2431 with better conductivity. In other embodiments, the material of the solder pad can also comprise other metals.

[0092] As an example, the material of the solder ball 2432 comprises tin. In other embodiments, the material of the solder ball can also comprise other metals.

[0093] It is also needed to be explained that the MEMS device further comprises a second insulating layer 242 located on the sidewall of a via (not labeled) for accommodating the conductive via structure 230, and the second insulating layer 242 also covers the surface of the side of the cap structure 222 opposite to the MEMS structure 221.

[0094] Correspondingly, the application also provides a forming method of a MEMS device. Figures 4 to 17 is a structure diagram corresponding to each step in the first embodiment of the forming method of the MEMS device of the application.

[0095] Reference Figure 4 , a control circuit structure 510 is provided, which comprises a first substrate 511 and a circuit wiring layer 512 on the first substrate 511, and the circuit wiring layer 512 has a first connection end 515.

[0096] The control circuit structure 510 is used for processing the electrical signal obtained by the MEMS device structure 520.

[0097] In this embodiment, the control circuit structure 510 has a first surface 5101.

[0098] As an example, the control circuit structure 510 is an ASIC chip. In other embodiments, the control circuit structure can also be other chips with control circuits.

[0099] The ASIC chip has complete integrated circuit functions, and can process the electrical signal input from the MEMS device structure 520, and output the signal required by the end user, or input the electrical signal to the MEMS device structure 520 in the opposite direction, so as to control the movement of the MEMS device structure 520.

[0100] The first substrate 511 is used for providing a process basis for forming the control circuit structure 510.

[0101] In this embodiment, the material of the first substrate 511 comprises silicon. In other embodiments, the material of the first substrate can also be germanium, silicon germanium, silicon carbide, gallium arsenide or indium gallium, and other materials, and the substrate can also be a silicon-on-insulator substrate 100 or a germanium-on-insulator substrate, and other types of substrates.

[0102] The circuit wiring layer 512 is used for realizing the transmission of the electrical signal, for example, for connecting each component (such as a transistor) of the control circuit structure 510 to each other, so as to form a complete circuit to realize the transmission of the electrical signal.

[0103] The first connecting end 515 is used to be bonded and electrically connected with the second connecting end 525, so as to realize the transmission of the electric signal between the control circuit structure 510 and the MEMS device structure.

[0104] In the embodiment, the material of the first connecting end 515 includes silicon, aluminum, germanium, tin or gold.

[0105] The silicon, aluminum, germanium, tin and gold are easy to realize a lower bonding temperature, so as to reduce the probability that the stress is too large due to the too high bonding temperature, thereby affecting the measurement accuracy of the MEMS device, for example, the deformation of the internal MEMS device due to the too high bonding temperature affects the measurement accuracy. Moreover, reducing the bonding temperature is also conducive to reducing the probability that the internal components of the control circuit structure 510 are affected by the bonding process.

[0106] Specifically, the material of the first connecting end 515 includes aluminum.

[0107] The conductivity and ductility of aluminum are better, and the cost is lower. Therefore, it is conducive to reducing the cost of the first connecting end 515 under the condition that the bonding temperature between the first connecting end 515 and the second connecting end 525 is low and the resistance is small.

[0108] In other embodiments, the material of the first connecting end can also include silicon, germanium, tin or gold. In other embodiments, the material of the first connecting end can also include other conductive materials capable of realizing a lower bonding temperature.

[0109] In the embodiment, the control circuit structure 510 further includes an interconnection layer located on the circuit wiring layer 512 and electrically connected with the circuit wiring layer 512, and the interconnection layer serves as the first connecting end 515.

[0110] In the embodiment, the first connecting end 515 is located on the first surface 5101.

[0111] Reference Figures 5 to 10 , a MEMS device structure 520 (as shown in Figure 10 ) is provided, and the MEMS device structure 520 includes a MEMS structure 521 having a second connecting end 525.

[0112] The MEMS device structure 520 is used to directly perceive the change of the external physical quantity (for example, acceleration, pressure, etc.) through the internal micro-mechanical structure, and convert the change of the external physical quantity into an electric signal such as a capacitance.

[0113] In the embodiment, the step of providing the MEMS device structure 520 includes: as Figures 5 to 9As shown, an initial MEMS device structure 520' is provided, which includes an initial MEMS structure 521', and a cap structure 522 which is stack bonded with the initial MEMS structure 521', the cap structure 522 is provided with a recess 526 in a side surface of the cap structure 522 facing the initial MEMS structure 521', and the initial MEMS structure 521' has the second connection end 525 on a side of the initial MEMS structure 521' facing away from the cap structure 522; as Figure 10 As shown, in a direction parallel to a top surface of the initial MEMS structure 521', a part of the initial MEMS structure 521' is removed to form support portions 523, and vibration portions 524 between adjacent support portions 523, and the remaining initial MEMS structure 521' serves as a MEMS structure 521.

[0114] After the initial MEMS device structure 520' and the cap structure 522 which is stack bonded with the initial MEMS structure 521' are provided, a part of the initial MEMS structure 521' is removed to form the support portions 523 and the vibration portions 524, which is conducive to avoiding the influence of the bonding of the initial MEMS device structure 520' and the cap structure 522 on the support portions 523 and the vibration portions 524.

[0115] The cap structure 522 serves to protect the initial MEMS structure 521' and the subsequently formed MEMS structure.

[0116] The recess 526 serves to enclose a cavity with the support portions 523 and the control circuit structure 510, thereby providing a vibration portion 524 in the cavity with a space capable of free movement.

[0117] The support portions 523 serve to provide support for the vibration portions 524.

[0118] The vibration portions 524 serve to directly sense changes in external physical quantities, and convert the changes in external physical quantities into electrical signals processable by the control circuit structure 510 through the joint action of the support portions 523.

[0119] The MEMS structure 521 has a second surface 5202 on a side of the second connection end 525, and the second connection end 525 is located on the second surface 5202; and a third surface 5203 on a side of the MEMS structure 521 facing the cap structure 522.

[0120] It should be noted that the MEMS structure 521 is electrically isolated from the cap structure 522.

[0121] Specifically, the step of providing the initial MEMS device structure 520' includes: as shown in Figures 5 to 6 providing a second substrate 521" (as shown in Figure 5 ), and providing a cap structure 522, one side of which is provided with a groove 526 (as shown in Figure 6 ); as shown in Figure 7 bonding any side of the second substrate 521" to the side of the cap structure 522 provided with the groove 526; as shown in Figures 8 to 9 forming a second connection terminal 525 on the side of the second substrate 521" away from the cap structure 522 to form the initial MEMS structure 521'.

[0122] Before forming the second connection terminal 525 on the side of the second substrate 521" away from the cap structure 522, bonding any side of the second substrate 521" to the side of the cap structure 522 provided with the groove 526 is advantageous to reduce the difficulty of bonding the second substrate 521" and the cap structure 522.

[0123] As an example, the material of the second substrate 521" includes silicon. In other embodiments, the material of the second substrate can also be silicon germanium, silicon carbide, gallium arsenide, or other materials such as indium gallium.

[0124] As an example, the process of bonding the second substrate 521" and the cap structure 522 includes a fusion bonding process.

[0125] More specifically, after bonding any side of the second substrate 521" to the side of the cap structure 522 provided with the groove 526, and before forming the second connection terminal 525, the method further includes: thinning the second substrate 521" to a predetermined thickness.

[0126] After bonding any side of the second substrate 521" to the side of the cap structure 522 provided with the groove 526, thinning the second substrate 521" is advantageous to reduce the probability of the second substrate 521" breaking into pieces.

[0127] In one embodiment, the step of forming the second connection terminal 525 includes: removing a portion of the thickness of the second substrate 521" in a portion of the area of the second substrate 521" on the side away from the groove 526 in a direction parallel to the top surface of the second substrate 521" to form a first bump 5231 (as shown in Figure 8 ); forming a first conductive layer covering the first bump 5231, the first conductive layer serving as the second connection terminal 525 (as shown inFigure 9 In the step of forming the support portions 523 and the vibration portions 524, in the remaining regions except the first protrusions 5231 and the first conductive layers, the initial MEMS structure 521' is removed in part regions, forming the support portions 523 including the first protrusions 5231 and the first conductive layers, and the vibration portions 524 located between adjacent support portions 523 (as shown in FIG. 5C). Figure 10 In the step of forming the support portions 523 and the vibration portions 524, in the remaining regions except the first protrusions 5231 and the first conductive layers, the initial MEMS structure 521' is removed in part regions, forming the support portions 523 including the first protrusions 5231 and the first conductive layers, and the vibration portions 524 located between adjacent support portions 523 (as shown in FIG. 5C).

[0128] After forming the first protrusions 5231, the first conductive layers covering the first protrusions 5231 are formed, so as to make the material of the first conductive layers different from the material of the first protrusions 5231, thereby facilitating the selection of a conductive material which is easy to realize a lower bonding temperature and low in price as the material of the first conductive layers, and further facilitating the reduction of the process cost of the MEMS device.

[0129] The first protrusions 5231 are used to make the vibration portions 524 have a gap with the first connecting ends 515, so as to ensure that the vibration portions 524 have a space for up and down vibration.

[0130] It should be noted that the process of removing part of the thickness of the second substrate 521" includes an anisotropic etching process, for example, an anisotropic dry etching process.

[0131] It should be further noted that the step of forming the first conductive layers covering the first protrusions 5231 includes: forming a first conductive material layer (not shown in the figure) on the second substrate 521", the first conductive material layer covering the top and sidewall of the first protrusions 5231 and covering the second substrate 521" on the side of the first protrusions 5231; removing the first conductive material layer in the remaining regions except the top and sidewall of the first protrusions 5231, and the remaining first conductive material layer on the top and sidewall of the first protrusions 5231 as the first conductive layers.

[0132] In other embodiments, the step of forming the second connecting ends includes: removing part of the thickness of the second substrate to form first protrusions as the second connecting ends in part regions of the second substrate on the side away from the groove in a direction parallel to the top surface of the second substrate, facilitating the reduction of process steps; in the step of forming the support portions and the vibration portions, the initial MEMS structure is removed in part regions in the remaining regions except the first protrusions, forming the support portions including the first protrusions, and the vibration portions located between adjacent support portions.

[0133] The second connecting end 525 is used to be bonded and electrically connected with the first connecting end 515, so as to realize the transmission of the electrical signal between the MEMS device structure 520 and the control circuit structure 510.

[0134] In the embodiment, the material of the second connecting end 525 includes germanium, aluminum, tin or gold.

[0135] Aluminum, germanium, tin and gold are easy to realize a lower bonding temperature.

[0136] As an example, the material of the second connecting end 525 is different from the material of the first connecting end 515. As another example, the material of the second connecting end can also be the same as the material of the first connecting end. That is, the material which can realize a lower bonding temperature when the second connecting end is bonded with the first connecting end can be used as the material of the second connecting end and the first connecting end.

[0137] Specifically, the material of the second connecting end 525 includes germanium.

[0138] Germanium is a commonly used material in semiconductor process, which is conducive to reducing the process cost of the second connecting end 525. Moreover, in the case that the material of the first connecting end 515 includes aluminum, the material of the second connecting end 525 includes germanium, which is conducive to realizing a lower bonding temperature.

[0139] In other embodiments, the material of the second connecting end can also include aluminum, tin or gold. In other embodiments, the material of the second connecting end can also include other conductive materials which can realize a lower bonding temperature.

[0140] In the embodiment, as shown in Figures 6 to 10 In the step of providing the MEMS device structure 520, the MEMS device structure 520 further includes a cap structure 522 which is stack-bonded with the MEMS structure 521. Specifically, the cap structure 522 includes a third substrate 527 and a bonding layer 528 on the third substrate 527, and the bonding layer 528 is bonded with the side of the MEMS structure 521 which is opposite to the second connecting end 525.

[0141] The third substrate 527 is used to provide a process basis for forming the cap structure 522.

[0142] As an example, the material of the third substrate 527 includes silicon. In other embodiments, the material of the third substrate can also be silicon germanium, silicon carbide, gallium arsenide or other materials such as indium gallium.

[0143] The bonding layer 528 is used for bonding with a side of the MEMS structure 521 which is opposite to the second connection end 525, so that the third substrate 527 is stacked with the MEMS structure 521.

[0144] Specifically, the material of the bonding layer 128 is an insulating material. The bonding layer 528 is used as a first insulating layer for electrically isolating the third substrate 527 from the MEMS structure 521, i.e. electrically isolating the cap structure 522 from the MEMS structure 521. More specifically, the material of the bonding layer 528 includes silicon oxide. In other embodiments, the material of the bonding layer can also be other insulating materials.

[0145] In other embodiments, the bonding layer can also be used for bonding with only a side of the MEMS structure which is opposite to the second connection end.

[0146] It should be noted that the side of the cap structure 522 which is towards the MEMS structure 521 is provided with a groove 526, i.e. the side of the cap structure 522 which is towards the third surface 1203 is provided with a groove 526; the bonding layer 528 also covers the inner wall of the groove 526, i.e. the bonding layer 528 conformally covers the third substrate 527.

[0147] The bonding layer 528 is used for protecting the groove 526, which is conducive to reducing the probability of damage to the third substrate 527 in the process of forming the MEMS structure 521. Moreover, the conformal coverage of the bonding layer 528 on the third substrate 127 is also conducive to simplifying the step of forming the bonding layer 528, thereby facilitating the reduction of the difficulty of forming the bonding layer 528.

[0148] More specifically, the process of forming the bonding layer 528 on the third substrate 527 includes one or both of a thermal oxidation process and a deposition process.

[0149] Reference Figure 11 The side of the MEMS device structure 520 which has the second connection end 525 is towards the side of the control circuit structure 510 which has the first connection end 515, and the first connection end 515 is bonded with the second connection end 525, so that the first connection end 515 is electrically connected with the second connection end 525.

[0150] The bonding of the first connection end 515 with the second connection end 525 is used for providing a process basis for the subsequent formation of a conductive via structure which is located in the MEMS device structure 520 and is electrically connected with the second connection end 525 and the first connection end 515.

[0151] In the step of bonding the first connecting end 515 and the second connecting end 525, the temperature of the bonding process is less than or equal to 450 degrees Celsius, which is beneficial to reduce the thermal budget of the MEMS device and reduce the probability of affecting the internal components of the control circuit structure 510.

[0152] In the step of providing the MEMS device structure 520, the initial MEMS device structure 520' includes an initial MEMS structure 521' and a cap structure 522 which is stack-bonded with the initial MEMS structure 521', the cap structure 522 is provided with a groove 526 in the side surface facing the initial MEMS structure 521', and the initial MEMS structure 521' has the second connecting end 525 on the side opposite to the cap structure 522; the initial MEMS structure 521' is removed in part in the direction parallel to the top surface of the initial MEMS structure 521' to form support portions 523 and vibration portions 524 between adjacent support portions 523, and the remaining initial MEMS structure 521' serves as the MEMS structure 521. Correspondingly, in the step of bonding the first connecting end 515 and the second connecting end 525, the vibration portions 524 are located in the cavity surrounded by the groove 526, the support portions 523, and the control circuit structure 510.

[0153] Reference Figures 12 to 14 In the step of bonding the first connecting end 515 and the second connecting end 525, the vibration portions 524 are located in the cavity surrounded by the groove 526, the support portions 523, and the control circuit structure 510. Figure 13 In the step of bonding the first connecting end 515 and the second connecting end 525, the vibration portions 524 are located in the cavity surrounded by the groove 526, the support portions 523, and the control circuit structure 510. Figure 14

[0154] In the step of forming the through hole 535 in the MEMS device structure 520, the process difficulty of forming the hole is reduced.

[0155] The hole is used to provide a spatial position for the subsequently formed conductive via structure.

[0156] In other embodiments, the hole penetrates the cap structure and is located in part of the thickness of the MEMS structure, and the hole exposes the top of the first conductive layer, so that the subsequently formed conductive via structure in the hole is in contact with the first conductive layer. In some other embodiments, the hole penetrates the cap structure and is located in part of the thickness of the MEMS structure, and the hole does not expose the top of the first conductive layer. ​

[0157] It is to be noted that the step of forming the via 535 forms a plurality of vias 535 in the MEMS device structure 520.

[0158] The plurality of vias 535 are used to provide spatial locations for a plurality of conductive via structures to be formed subsequently.

[0159] It is also to be noted that the lateral dimension of the via 535 is smaller than the lateral dimension of the first bump 5231. The lateral dimension of the first bump 5231 is larger than that of the via 535, which is advantageous in maintaining the structural integrity of the first bump 5231 and the first conductive layer during the process of forming the via 535, so that the electrical connection between the second connection end 525 and the first connection end 515 is better.

[0160] It is to be understood that the lateral dimension of the conductive via structure to be formed subsequently is also smaller than the lateral dimension of the first bump 5231.

[0161] It is to be further noted that the step of forming the second insulating layer 542 also covers the surface of the cap structure 522 on the side facing away from the MEMS structure 521.

[0162] The second insulating layer 542 is located on the sidewall of the via 535 for accommodating the conductive via structure 530, which is advantageous in electrically isolating the conductive via structure 530 from the rest of the MEMS device structure 520 except the second connection end 525. In some other embodiments, the second insulating layer can not be formed in the case where the material of the region of the MEMS device structure penetrated by the conductive via structure is an insulating material.

[0163] The second insulating layer 542 also covers the surface of the cap structure 522 on the side facing away from the MEMS structure 521, which is used to electrically isolate the re-distribution layer to be formed subsequently from the cap structure 522. In some other embodiments, other ways can also be used to electrically isolate the re-distribution layer from the cap structure.

[0164] As an example, the step of forming the second insulating layer includes: forming a second insulating material layer (not shown in the figure) on the bottom and sidewall of the via 535 and the third substrate 527 of the cap structure 522 outside the via 535; removing the second insulating material layer on the bottom of the via 535, and the remaining second insulating material layer serves as the second insulating layer 542.

[0165] As another example, the material of the second insulating layer 542 includes silicon oxide. In some other embodiments, the material of the second insulating layer can also be other insulating materials.

[0166] In one embodiment, the step of forming the via 535 in the MEMS device structure 520 comprises: as shown in Figure 10 In the step of providing the MEMS device structure 520, a first hole is formed in the MEMS structure, the first hole is a first via 537, the first via 537 penetrates the MEMS structure, i.e. the first via 537 is formed in the MEMS structure, and the MEMS device structure further comprises a cap structure which is stack bonded with the MEMS structure; as shown in Figures 12 to 13 After the first connection end 515 is bonded with the second connection end 525, a second via 536 is formed in the cap structure 522, the second via 536 penetrates the first via 537, and the second via 536 and the first via 537 constitute the via 535.

[0167] The first via 537 is formed in the MEMS structure first, and then the second via 536 is formed in the cap structure 522, so that the aspect ratio of the second via 536 formed in the cap structure 522 is small, thereby facilitating the formation of the via 535.

[0168] It should be noted that the first via 537 can be formed in the step of forming the support part 523 and the vibration part 524, thereby facilitating the saving of process steps, and combining the process step of forming the first via 537 with the existing process, thereby facilitating the reduction of the modification to the existing process. It can be understood that the first via can also be formed after the formation of the support part and the vibration part, or the first via can be formed before the formation of the support part and the vibration part.

[0169] In other embodiments, in the step of providing the MEMS device structure, a first hole is formed in the MEMS structure, the first hole exposes the first conductive layer. In some other embodiments, in the step of providing the MEMS device structure, the first hole is located in the MEMS structure with a partial thickness, and does not expose the first conductive layer.

[0170] In yet some other embodiments, in the step of providing the MEMS device structure, the MEMS device structure further comprises a cap structure which is stack bonded with the MEMS structure; and the step of forming the via in the MEMS device structure comprises: after the first connection end is bonded with the second connection end, a second via is formed which penetrates the cap structure; the MEMS structure at the bottom of the second via is removed, a first via is formed in the MEMS structure which penetrates the second via, and the first via and the second via constitute the via.

[0171] As an example, in the step of providing the MEMS device structure 520, the MEMS device structure 520 further comprises a cap structure 522 stacked bonded with the MEMS structure 521, the cap structure 522 comprises a third substrate 527, and a bonding layer 528 on the third substrate 527, the bonding layer 528 is bonded with a side of the MEMS structure 521 opposite to the second connecting end 525; the step of forming the second via hole 536 comprises: as shown in Figure 12 forming a second initial via hole 536' through the third substrate 527 at a preset position of the third substrate 527; as shown in Figure 13 removing the bonding layer 528 at the bottom of the second initial via hole 536', to form the second via hole 536.

[0172] The second initial via hole 536' is formed in the third substrate 527 first, and then the bonding layer 528 at the bottom of the second initial via hole 536' is removed to form the second via hole 536, which is conducive to reducing the difficulty of forming the second via hole 536.

[0173] As another example, the second via hole can also be formed directly in the cap structure.

[0174] In the embodiment, after the first connecting end 515 is bonded with the second connecting end 525, before the via hole 535 is formed in the MEMS device structure 520, the cap structure 522 is removed by a partial thickness.

[0175] The cap structure 522 is removed by a partial thickness before the via hole 535 is formed in the MEMS device structure 520, which is conducive to reducing the thickness of the cap structure 522 to be removed in the step of forming the via hole 535, thereby facilitating the reduction of the aspect ratio of the via hole 535, and correspondingly facilitating the reduction of the difficulty of forming the via hole 535.

[0176] Specifically, the cap structure 522 is removed by a partial thickness after the first connecting end 515 is bonded with the second connecting end 525, and before the second initial via hole 536' is formed.

[0177] Referring to Figure 15 , and referring to Figure 14 , a conductive via hole structure 530 is formed in the MEMS device structure 520, one end of the conductive via hole structure 530 is electrically connected with the second connecting end 525 and the first connecting end 515, and the other end of the conductive via hole structure 530 is exposed by the MEMS device structure 520.

[0178] The conductive via hole structure 530 is used for electrical connection with an external circuit.

[0179] The conductive via structure 530 is located in the MEMS device structure 520, which avoids setting the conductive via structure in the control circuit structure, and also avoids increasing the parasitic capacitance of the control circuit structure caused by setting the conductive via structure in the control circuit structure, thereby facilitating to reduce the parasitic capacitance in the control circuit structure 510, improve the processing precision of the control circuit in the control circuit structure 510, and further facilitate to improve the measurement precision of the MEMS device; and compared with the control circuit structure 510, the internal structure of the MEMS device structure 520 is relatively simple, and setting the conductive via structure 530 in the MEMS device structure 520 facilitates to increase the size of the conductive via structure 530, thereby facilitating to increase the process window of the conductive via structure 530, reduce the process difficulty of forming the conductive via structure 530, and also facilitate to reduce the probability of poor electrical connection between the control circuit structure 510 and the MEMS device structure 520 after bonding caused by the small size of the conductive via structure 530 and overlay shift, and further facilitate to reduce the probability of failure of the MEMS device. Therefore, the technical scheme of the present application facilitates to improve the yield and electrical performance of the MEMS device.

[0180] In the present embodiment, a hole is formed in the MEMS device structure 520, and the hole is a through hole 535, and correspondingly, in the step of forming the conductive structure 530, the conductive via structure 530 penetrates the MEMS device structure 520, that is, the conductive via structure 530 penetrates the cap structure 522 and the MEMS structure 521, and the MEMS device structure 520 exposes both ends of the conductive via structure 530.

[0181] The conductive via structure 530 penetrates the MEMS device structure 520, which facilitates to reduce the difficulty of forming the conductive via structure 530.

[0182] In other embodiments, in the step of providing the MEMS device structure, the hole does not penetrate the MEMS device structure; accordingly, the conductive via structure can also be located in the MEMS device structure with a partial thickness. For example, in the step of providing the MEMS device structure, the first hole exposing the first conductive layer is formed in the MEMS structure, in the step of forming the hole, the second via penetrating the cap structure is formed, and accordingly, in the step of forming the conductive via structure in the first hole and the second via, the conductive via structure penetrates the cap structure, the cap structure exposes one end of the conductive via structure away from the control circuit structure, and the conductive via structure is located in the MEMS structure with a partial thickness, and one end of the conductive via structure towards the control circuit structure is in contact with and electrically connected to the first conductive layer. In yet other embodiments, in the step of providing the MEMS device structure, the first hole does not expose the first conductive layer, and accordingly, one end of the conductive via structure towards the control circuit structure can also not be in contact with the first conductive layer, that is, the conductive via structure is only electrically connected to the first conductive layer.

[0183] In the embodiments, in the step of forming the conductive via structure, the conductive via structure is located at the edge of the MEMS device structure, which is advantageous to reduce the modification to the existing MEMS device structure 520 while further increasing the size of the conductive via structure 530. In other embodiments, the conductive via structure can also be located at other positions of the MEMS device structure.

[0184] Specifically, in the step of forming the conductive via structure 530, the number of the conductive via structure 530 is multiple.

[0185] In one embodiment, a second insulating layer 542 is formed on the sidewall of the via 535, and the second insulating layer 542 also covers the side of the cap structure 522 away from the MEMS structure 521 (as shown in FIG. 5B). Figure 14 Accordingly, the step of forming the conductive via structure 530 includes forming a second conductive layer 532 in the remaining space of the via 535 (as shown in FIG. 5C). Figure 15

[0186] It should be noted that the material of the second conductive layer 532 includes copper. In other embodiments, the material of the second conductive layer can also include other conductive materials.

[0187] It should also be noted that, as shown in FIG. 5D, the second conductive layer 532 is in contact with the first conductive layer 531. Figure 14 ​Before forming the second conductive layer 532 in the remaining space of the via 535, the method further comprises: forming an adhesion layer 531 on the second insulating layer 542; and forming the second conductive layer 532 on the adhesion layer 531.

[0188] The adhesion layer 531 is used to improve the adhesion between the second conductive layer 532 and the second insulating layer 542. Accordingly, the conductive via structure 530 comprises the adhesion layer 531 and the second conductive layer 532 in the via 535.

[0189] The step of forming the adhesion layer 531 comprises: forming an adhesion material layer (not shown in the figure) on the second insulating layer 542 and the bottom of the via 535; and removing the adhesion material layer at the bottom of the via 535, and the remaining adhesion material layer serves as the adhesion layer 531.

[0190] As an example, the step of forming the conductive via structure 530 comprises: forming the second conductive layer 532 in the remaining space of the via 535, and the second conductive layer 532 also covers the second insulating layer 542 outside the via 535, which is conducive to simplifying the subsequent step of forming a re-distribution layer.

[0191] Specifically, the step of forming the second conductive layer 532 comprises: forming a second conductive material layer (not shown in the figure) in the remaining space of the via 535, and the second conductive material layer also covers the second insulating layer 542 outside the via 535; and removing part of the thickness of the second conductive material layer outside the via 535, and the remaining second conductive material layer serves as the second conductive layer 532.

[0192] More specifically, the part of the thickness of the second conductive material layer outside the via 535 is removed by a chemical mechanical polishing (CMP) process.

[0193] The thickness of the second conductive material layer outside the via 535 (i.e., the second conductive layer 532 outside the via 535) should not be too small or too large. If the thickness of the second conductive layer 532 outside the via 535 is too small or too large, it will increase the difficulty of forming a re-distribution layer subsequently. Therefore, in the embodiment, the thickness of the second conductive layer 532 outside the via 535 ranges from 0.1 microns to 10 microns.

[0194] Reference is made to Figures 16 to 17 Reference is made to Figure 15In the embodiment, after the conductive via structure 530 is formed, the method further includes: forming a plurality of redistribution layers 540 on the surface of the cap structure 522 away from the MEMS structure 521, each of the redistribution layers 540 is electrically connected with a corresponding conductive via structure 530 (as shown in FIG. 5B); forming second bumps 541 on the redistribution layers 540, each of the second bumps 541 on different redistribution layers 540 is staggered (as shown in FIG. 5C)。 Figure 15 Figure 16 Figure 17

[0195] wherein, Figure 16 is a top view after the second bump 541 is formed, Figure 17 is a cross-sectional view at AA1. Figure 16

[0196] It should be noted that, in order to clearly show the structure of the MEMS device, Figure 16 the redistribution layers are simplified, and the second insulating layer and part of the second conductive layer on the top of the conductive via structure are omitted.

[0197] The redistribution layers 540 are used to provide a process platform for the second bump 541, and to redistribute the connection end of the conductive via structure 530, so that the layout of the connection end of the redistributed conductive via structure 530 meets the process requirements.

[0198] The second bump 541 is used to connect with an external circuit, so that the conductive via structure 530 is electrically connected with the external circuit. Moreover, each of the second bumps 541 on different redistribution layers 540 is staggered, which is conducive to reducing the probability of contact between adjacent second bumps 541.

[0199] As an example, the second bump 541 is a solder ball. The material of the solder ball can be tin or other suitable materials.

[0200] More specifically, the step of forming the redistribution layer 540 includes: removing the second conductive layer 532 in part of the area outside the conductive via structure 530, and the remaining second conductive layer 532 on the surface of the cap structure 522 away from the MEMS structure 521 is used as a redistribution layer 540, which is conducive to simplifying the step of forming a second conductive layer 532 on the second insulating layer 542 outside the via 535, which is used as a process basis for forming a redistribution layer 540, thereby facilitating the step of forming the redistribution layer 540.

[0201] ​​​​In the embodiment, the second conductive layer 532 outside the via hole 535 has a thickness ranging from 0.1 microns to 10 microns. Correspondingly, the thickness of the re-wiring layer 540 also ranges from 0.1 microns to 10 microns.

[0202] The application further provides a method for forming the MEMS device of the second embodiment. Figure 18 FIG. 6 is a structural schematic diagram corresponding to each step in the method for forming the MEMS device of the second embodiment of the application.

[0203] The second embodiment is the same as the first embodiment, and thus will not be repeated here. The second embodiment is different from the first embodiment in that Figure 18 After the conductive via hole structure 630 is formed, the method further includes forming a third bump 643 on the top of the conductive via hole structure 630, and the third bump 643 is electrically connected to the conductive via hole structure 630.

[0204] The third bump 643 is located on the top of the conductive via hole structure 630 and is electrically connected to the conductive via hole structure 630, which is advantageous for simplifying the complexity of the circuit on the surface of the side of the cap structure 622 away from the MEMS structure 621, thereby facilitating the simplification of the process flow of the MEMS device.

[0205] It should be noted that the step of forming the third bump 643 includes forming a solder pad 6431 on the top of the conductive via hole structure 630, and the solder pad 6431 is electrically connected to the conductive via hole structure 630; and forming a solder ball 6432 on the solder pad 6431, and the solder ball 6432 is electrically connected to the solder pad 6431. In other embodiments, the step of forming the third bump only includes forming a solder pad on the top of the conductive via hole structure.

[0206] The material of the solder pad 6431 includes aluminum. Aluminum has good metal conductivity and small resistance, which is advantageous for obtaining a solder pad 6431 with good conductivity. In other embodiments, the material of the solder pad can also include other metals.

[0207] As an example, the material of the solder ball 6432 includes tin. In other embodiments, the material of the solder ball can also include other metals.

[0208] It should be further noted that, before the conductive via hole structure 630 is formed, the method further includes forming a second insulating layer 642 on the sidewall of the via hole (not labeled), and the second insulating layer 642 also covers the surface of the side of the cap structure 622 away from the MEMS structure 621.

[0209] More preferably, the step of forming the conductive via structure 630 includes: forming a second conductive material layer (not shown) in the remaining space of the via, the second conductive material layer also covering the second insulating layer 642 outside the via 635; and removing the second conductive material layer outside the via, the remaining second conductive material layer in the via serving as the second conductive layer 632.

[0210] When the second conductive material layer outside the via is removed, there is no need to control the remaining thickness of the second conductive material layer outside the via, which is conducive to reducing the difficulty of removing the second conductive material layer outside the via.

[0211] As an example, the chemical mechanical polishing process is used to remove the second conductive material layer outside the via.

[0212] It should be noted that the MEMS device can be formed by using the forming method described in the foregoing embodiments, or can be formed by using other forming methods. For the specific description of the MEMS device in the present embodiment, reference can be made to the corresponding description in the foregoing embodiments, which will not be described herein again.

[0213] Correspondingly, the present application also provides an electronic device.

[0214] In combination with reference Figures 1 to 2 In the present embodiment, the electronic device comprises the MEMS device described in any of the embodiments of the present application.

[0215] The MEMS device can be assembled into various electronic devices. As can be known from the foregoing analysis, since the conductive via structure 130 is arranged in the MEMS device structure 120, the conductive via structure 130 is avoided to be arranged in the control circuit structure 110, and accordingly, the parasitic capacitance of the control circuit structure 110 is reduced, the processing precision of the control circuit in the control circuit structure 110 is improved, and the measurement precision of the MEMS device is improved. Moreover, compared with the control circuit structure 110, the internal structure of the MEMS device structure 120 is relatively simple, the conductive via structure 130 is arranged in the MEMS device structure 120, the size of the conductive via structure 130 is increased, the process window of the conductive via structure 130 is increased, the process difficulty of forming the conductive via structure 130 is reduced, the probability of poor electrical connection between the control circuit structure 110 and the MEMS device structure 120 after bonding due to the small size of the conductive via structure 130 and overlay shift is reduced, and the probability of failure of the MEMS device is reduced. Therefore, the technical scheme of the present application is beneficial to improve the yield and electrical performance of the MEMS device.

[0216] The electronic device can be a smart phone, a wearable device, an electronic game device, etc.

[0217] The electronic device provided in the present application comprises the MEMS device described above, and therefore, the electronic device provided in the present application and the MEMS device of the technical scheme described above can solve the same technical problems and achieve the same expected effects. For the specific description of the MEMS device in the electronic device, reference can be made to the related description in the foregoing embodiments, which will not be repeated here.

[0218] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art, without departing from the spirit and scope of the present application, can make various changes and modifications, and therefore, the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A MEMS device, characterized in that: include: A control circuit structure, comprising a first substrate and a circuit wiring layer located on the first substrate, wherein the circuit wiring layer has a first connection terminal; A MEMS device structure stacked with the control circuit structure, the MEMS device structure comprising a MEMS structure having a second connection end, the second connection end being bonded and electrically connected to the first connection end; A conductive through-hole structure is located in the MEMS device structure, wherein one end of the conductive through-hole structure facing the control circuit structure is electrically connected to the second connection end and the first connection end, and one end of the conductive through-hole structure facing away from the control circuit structure is exposed by the MEMS device structure.

2. The MEMS device according to claim 1, wherein: The MEMS device structure further includes: a cap structure, stacked and bonded with the MEMS structure, wherein a groove is provided in a surface of the cap structure facing the MEMS structure; The MEMS structure has the second connection end on the side facing away from the cap structure, and along a direction parallel to the top surface of the MEMS structure, the MEMS structure includes a supporting part and a vibrating part located between adjacent supporting parts, and the vibrating part is located in a cavity surrounded by the groove, the supporting part, and the control circuit structure.

3. The MEMS device according to claim 2, wherein: The supporting portion includes a first bump protruding from the vibrating portion, and a first conductive layer covering the first bump, wherein the first conductive layer serves as the second connecting end; or, The supporting portion includes a first bump protruding from the vibrating portion, and the first bump serves as the second connecting end.

4. The MEMS device according to claim 1, wherein: The MEMS device structure further includes: a cap structure, which is stacked and bonded with the MEMS structure; the cap structure includes: a third substrate; A bonding layer is located on the third substrate, and the bonding layer is bonded to a surface of the MEMS structure that is away from the second connection end.

5. The MEMS device according to claim 1, wherein: The conductive through-hole structure is located at an edge of the MEMS device structure.

6. The MEMS device according to claim 5, wherein: There are multiple conductive through-hole structures; The MEMS device also includes: a cap structure, stacked and bonded with the MEMS structure; multiple redistribution layers, located on the surface of the cap structure facing away from the MEMS structure, each of the redistribution layers is electrically connected to the corresponding conductive through-hole structure; second bumps, located on the redistribution layers, and the second bumps located on different redistribution layers are staggered.

7. The MEMS device according to claim 6, wherein: The MEMS device further includes: a second insulating layer located on the sidewall of the through hole for accommodating the conductive through hole structure, the second insulating layer also covering the surface of the cap structure facing away from the MEMS structure; The conductive via structure includes a second conductive layer located in the via, and the second conductive layer is also located on a portion of the second insulating layer outside the conductive via structure. The second conductive layer outside the conductive via structure serves as a rewiring layer.

8. The MEMS device according to claim 1, wherein: The MEMS device further includes a third bump located on top of the conductive via structure and electrically connected to the conductive via structure.

9. The MEMS device according to claim 1, wherein: The material of the first connection end includes silicon, aluminum, germanium, tin or gold; The material of the second connection end includes germanium, aluminum, tin or gold.

10. The MEMS device according to claim 1, wherein: The conductive through-hole structure runs through the MEMS device structure.

11. A method for forming a MEMS device, characterized in that: include: A control circuit structure is provided, the control circuit structure comprising a first substrate and a circuit wiring layer located on the first substrate, the circuit wiring layer having a first connection terminal; Providing a MEMS device structure, the MEMS device structure comprising a MEMS structure, the MEMS structure having a second connection end; Positioning the side of the MEMS device structure having the second connection end toward the side of the control circuit structure having the first connection end, and bonding the first connection end to the second connection end so that the first connection end and the second connection end are electrically connected; A conductive via structure is formed in the MEMS device structure, one end of the conductive via structure is electrically connected to the second connection end and the first connection end, and the other end of the conductive via structure is exposed by the MEMS device structure.

12. The method for forming a MEMS device according to claim 11, wherein: The steps of providing a MEMS device structure include: Providing an initial MEMS device structure, the initial MEMS device structure comprising an initial MEMS structure and a cap structure stacked and bonded to the initial MEMS structure, the cap structure having a groove in a surface facing the initial MEMS structure, and the initial MEMS structure having the second connection end on a side facing away from the cap structure; removing a portion of the initial MEMS structure in a direction parallel to a top surface of the initial MEMS structure to form a support portion and a vibration portion located between adjacent support portions, with the remaining initial MEMS structure serving as a MEMS structure; In the step of bonding the first connecting end to the second connecting end, the vibration part is located in a cavity surrounded by the groove, the support part, and the control circuit structure.

13. The method for forming a MEMS device according to claim 12, wherein: The step of providing the initial MEMS device structure comprises: Providing a second substrate and a cap structure, wherein a groove is provided in one side of the cap structure; bonding any one surface of the second substrate to the surface of the cap structure on the side where the groove is provided; A second connecting terminal is formed on a side of the second substrate facing away from the cap structure to form the initial MEMS structure.

14. The method for forming a MEMS device according to claim 13, wherein: The step of forming the second connecting terminal includes: removing a portion of the thickness of the second substrate in a portion of the second substrate facing away from the groove in a direction parallel to the top surface of the second substrate to form a first bump; forming a first conductive layer covering the first bump, the first conductive layer serving as the second connecting terminal; In the step of forming the supporting portion and the vibrating portion, in the remaining region except the first bump and the first conductive layer, the initial MEMS structure is partially removed to form a supporting portion including the first bump and the first conductive layer, and a vibrating portion located between adjacent supporting portions; or, The step of forming the second connecting end includes: removing a portion of the thickness of the second substrate in a portion of the second substrate facing away from the groove in a direction parallel to the top surface of the second substrate to form a first bump, wherein the first bump serves as the second connecting end; In the step of forming the supporting portion and the vibrating portion, in the remaining region except the first bump, a portion of the initial MEMS structure is removed to form the supporting portion including the first bump and the vibrating portion located between adjacent supporting portions.

15. The method for forming a MEMS device according to claim 11, wherein: In the step of providing a MEMS device structure, the MEMS device structure also includes a cap structure stacked and bonded with the MEMS structure, the cap structure includes a third substrate and a bonding layer located on the third substrate, and the bonding layer is bonded to a side of the MEMS structure facing away from the second connection end.

16. The method for forming a MEMS device according to claim 11, wherein: After bonding the first connection end and the second connection end and before forming the conductive through-hole structure, the method further includes: forming a through hole in the MEMS device structure; forming a second insulating layer on the sidewalls of the through hole; The step of forming the conductive via structure includes forming a second conductive layer in the remaining space of the via.

17. The method for forming a MEMS device according to claim 16, wherein: The step of forming a through hole in the MEMS device structure includes: In the step of providing the MEMS device structure, a first through hole is formed in the MEMS structure, and the MEMS device structure further includes a cap structure stacked and bonded with the MEMS structure; After bonding the first connecting end to the second connecting end, a second through hole is formed in the cap structure to communicate with the first through hole, wherein the second through hole and the first through hole constitute a through hole; or, In the step of providing the MEMS device structure, the MEMS device structure further includes a cap structure stacked and bonded with the MEMS structure; The step of forming a through hole in the MEMS device structure includes: After bonding the first connecting end and the second connecting end, a second through hole penetrating the cap structure is formed; The MEMS structure at the bottom of the second through hole is removed, and a first through hole penetrating the second through hole is formed in the MEMS structure. The first through hole and the second through hole constitute a through hole.

18. The method for forming a MEMS device according to claim 17, wherein: In the step of providing a MEMS device structure, the MEMS device structure further includes a cap structure stacked and bonded with the MEMS structure, the cap structure including a third substrate and a bonding layer located on the third substrate, the bonding layer being bonded to a surface of the MEMS structure facing away from the second connection end; The step of forming the second through hole includes: forming a second initial through hole penetrating the third substrate at a preset position of the third substrate; The bonding layer at the bottom of the second initial through hole is removed to form a second through hole.

19. The method for forming a MEMS device according to claim 16, wherein: In the step of providing a MEMS device structure, the MEMS device structure further includes a cap structure stacked and bonded with the MEMS structure; After bonding the first connecting end to the second connecting end and before forming a through hole in the MEMS device structure, the method further includes: removing a portion of the thickness of the cap structure.

20. The method for forming a MEMS device according to claim 11, wherein: In the step of forming the conductive via structure, the conductive via structure is located at an edge of the MEMS device structure.

21. The method for forming a MEMS device according to claim 20, wherein: In the step of providing a MEMS device structure, the MEMS device structure further includes a cap structure stacked and bonded with the MEMS structure; In the step of forming the conductive through-hole structure, the number of the conductive through-hole structures is multiple; After forming the conductive through-hole structure, the method further includes: forming a plurality of redistribution layers on a surface of the cap structure facing away from the MEMS structure, wherein each redistribution layer is electrically connected to a corresponding conductive through-hole structure; Second bumps are formed on the rewiring layer, and the second bumps on different rewiring layers are staggered.

22. The method for forming a MEMS device according to claim 21, wherein: After bonding the first connection end and the second connection end and before forming the conductive through-hole structure, the method further includes: forming a plurality of through holes in the MEMS device structure; forming a second insulating layer on the sidewall of the through hole, wherein the second insulating layer also covers the surface of the cap structure facing away from the MEMS structure; The step of forming the conductive through-hole structure includes: forming a second conductive layer in the remaining space of the through-hole, wherein the second conductive layer also covers the second insulating layer outside the through-hole; The step of forming the rewiring layer includes: removing the second conductive layer in a partial area outside the conductive via structure, and using the remaining second conductive layer on the surface of the cap structure facing away from the MEMS structure as the rewiring layer.

23. The method for forming a MEMS device according to claim 11, wherein: After forming the conductive via structure, the method further includes: forming a third bump on the top of the conductive via structure, wherein the third bump is electrically connected to the conductive via structure.

24. An electronic device, characterized in that: include: The MEMS device according to any one of claims 1 to 10.

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