MEMS chip and manufacturing method therefor, and electronic device

Abstract

A MEMS chip and a manufacturing method therefor, and an electronic device. The MEMS chip comprises: a substrate; a supporting beam fixed on the substrate; and comb tooth pairs comprising a plurality of first comb teeth and a plurality of second comb teeth, wherein the plurality of first comb teeth are fixed on the substrate, and the plurality of second comb teeth are fixed on the supporting beam; or, the plurality of first comb teeth are fixed on the supporting beam, and the plurality of second comb teeth are fixed on the substrate. The plurality of first comb teeth and the plurality of second comb teeth are arranged in the same direction alternately. The first comb teeth comprise at least two conductive layers stacked in a thickness direction, and the second comb teeth comprise at least one conductive layer. At least one conductive layer of the first comb teeth and the at least one conductive layer of the second comb teeth are arranged on the same layer, so that a MEMS chip using non-coplanar comb tooth pairs and a MEMS chip using coplanar comb tooth pairs can be manufactured on the basis of the same process platform.

Description

MEMS chip, manufacturing method thereof, and electronic device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 9, 2023, with application number 202311160545.4 and invention name “MEMS chip, manufacturing method thereof and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of semiconductor technology, and in particular to a MEMS chip, a manufacturing method thereof, and an electronic device. Background Art

[0003] Microelectromechanical systems (MEMS) chips are widely used in fields such as optical communications and consumer electronics. MEMS chips can include comb teeth. Their operating principle is to use the potential difference applied to the comb teeth to generate electrostatic force and torque, driving the movement of components on the MEMS chip.

[0004] Comb tooth pairs can be divided into coplanar comb tooth pairs and skew comb tooth pairs. Coplanar comb tooth pairs refer to pairs in which the driving comb teeth and driven comb teeth are arranged on the same layer. Skew comb tooth pairs refer to pairs in which the driving comb teeth and driven comb teeth are arranged on different layers. Given the different structures of coplanar comb tooth pairs and skew comb tooth pairs, they are usually manufactured based on different process platforms. Therefore, two different process platforms are required to manufacture MEMS chips with coplanar comb tooth structures and MEMS chips with skew comb tooth structures, respectively.

[0005] Summary of the Invention

[0006] In order to solve the above technical problems, the present application provides a MEMS chip, a manufacturing method thereof, and an electronic device, which can enable MEMS chips using skew comb tooth pairs and MEMS chips using coplanar comb tooth pairs to be manufactured based on the same process platform.

[0007] In a first aspect of the present application, a MEMS chip is provided, comprising: a substrate, a support beam, and a comb tooth pair. The support beam is connected to the substrate and has a suspended portion.

[0008] The comb teeth pair includes a plurality of first comb teeth and a plurality of second comb teeth. In one possible embodiment, the plurality of first comb teeth are fixed to the base plate, and the plurality of second comb teeth pairs are fixed to the suspended portion. In another possible embodiment, the plurality of first comb teeth are fixed to the suspended portion, and the plurality of second comb teeth are fixed to the base plate.

[0009] The plurality of first comb teeth are arranged in a direction perpendicular to the thickness of the MEMS chip, and the plurality of second comb teeth are arranged in a direction perpendicular to the thickness. The plurality of first comb teeth and the plurality of second comb teeth are arranged in the same direction and alternately. The first comb teeth include at least two conductive layers stacked in the thickness direction, and the second comb teeth include at least one conductive layer. The at least one conductive layer of the first comb teeth and the at least one conductive layer of the second comb teeth are arranged on the same layer.

[0010] Because the first comb teeth include at least two conductive layers, the at least two conductive layers can be separately fabricated using a deposition-first, then etching process. The at least one conductive layer of the second comb teeth is provided on the same layer as the at least one conductive layer of the first comb teeth. Therefore, the second comb teeth can be fabricated simultaneously with the first comb teeth. In other words, the first and second comb teeth can be fabricated on the same process platform and in the same step, thereby reducing the complexity of the MEMS chip fabrication process and lowering manufacturing costs.

[0011] In addition, when the MEMS chip is used, different voltage signals can be provided to at least two stacked conductive layers, so that the same MEMS chip can realize multiple different functions, thereby improving the integration of the MEMS chip.

[0012] In some possible implementations, the comb tooth pair is a coplanar comb tooth pair, then the second comb tooth includes at least two conductive layers, the number of conductive layers of the first comb tooth is the same as the number of conductive layers of the second comb tooth, and the at least two conductive layers of the first comb tooth and the at least two conductive layers of the second comb tooth are respectively arranged in the same layer. Exemplarily, the number of conductive layers in the first comb tooth and the second comb tooth is two, three or more layers. In this way, when making the comb tooth pair, at least two polysilicon layers and an insulating layer located between two adjacent polysilicon layers can be respectively made by deposition, and then the first comb tooth and the second comb tooth can be etched out by etching. Therefore, the first comb tooth and the second comb tooth can be made on the same process platform, and the first comb tooth and the second comb tooth can be made at the same time.

[0013] The second comb teeth may include a third conductive layer and a fourth conductive layer, wherein the first conductive layer and the third conductive layer are provided on the same layer, and the second conductive layer and the fourth conductive layer are provided on the same layer. The thickness of the third conductive layer may be the same as that of the first conductive layer, and the thickness of the fourth conductive layer may be the same as that of the second conductive layer.

[0014] In other possible implementations, the comb tooth pair is a skewed comb tooth pair, the second comb tooth includes a conductive layer, and the at least two conductive layers of the first comb tooth include a first conductive layer and a second conductive layer. The conductive layer of the second comb tooth is provided on the same layer as the first conductive layer, or the conductive layer of the second comb tooth is provided on the same layer as the second conductive layer. In this way, when manufacturing the comb tooth pair, at least two polysilicon layers and an insulating layer located between two adjacent polysilicon layers can be separately manufactured by deposition, and then the first comb teeth and the second comb teeth can be etched out by etching. Therefore, the first comb teeth and the second comb teeth can be manufactured on the same process platform, and the first comb teeth and the second comb teeth can be manufactured simultaneously.

[0015] Regarding the relationship between the thickness of the first conductive layer and the thickness of the second conductive layer, in one possible embodiment, the thickness of the first conductive layer is the same as the thickness of the second conductive layer. When the second comb teeth include a third conductive layer and a fourth conductive layer, the thickness of the third conductive layer is also the same as the thickness of the fourth conductive layer.

[0016] In another possible implementation, the thickness of the first conductive layer is different from the thickness of the second conductive layer. When the second comb teeth include a third conductive layer and a fourth conductive layer, the thickness of the third conductive layer is also different from the thickness of the fourth conductive layer.

[0017] The MEMS chip may further include a plurality of signal electrodes, each of which may receive a different voltage signal, and some of the signal electrodes may receive the same voltage signal.

[0018] Regarding the structure of the MEMS chip, in one possible embodiment, the number of fixing parts and the number of comb tooth pairs are both two, the two fixing parts are respectively located on opposite sides of the support beam, and each comb tooth pair is respectively fixed between each fixing part and the support beam.

[0019] In another possible embodiment, there are four fixing portions and four comb tooth pairs, the four fixing portions are arranged in a rectangular array on the periphery of the support beam, and a comb tooth pair is connected between each fixing portion and the support beam.

[0020] When the first comb teeth include a first conductive layer and a second conductive layer, and the second comb teeth include a third conductive layer and a fourth conductive layer, the first and fourth conductive layers are connected to different signal electrodes, and the second and third conductive layers are connected to different signal electrodes. In this way, the first and second conductive layers, and the third and fourth conductive layers, can receive different voltage signals through different signal electrodes. For example, the first conductive layer can receive a first voltage, the second conductive layer can receive a second voltage, the third conductive layer can receive a third voltage, and the fourth conductive layer can receive a fourth voltage. The first voltage is different from the fourth voltage, and the second voltage is different from the third voltage. When the first voltage is greater than the fourth voltage, a potential difference can be generated between the first and fourth conductive layers. When the third voltage is also greater than the second voltage, a potential difference can also be generated between the third and second conductive layers, generating an electrostatic force between the first and second comb teeth, thereby driving the second comb teeth to rotate. Because the second comb teeth are fixed to the suspended portion of the support beam, the second comb teeth can drive the support beam to rotate. Therefore, the MEMS chip of this application can be used in devices requiring a rotating pair, for example, a MEMS galvanometer.

[0021] The MEMS chip may further include a ground electrode. In one possible embodiment, at least two conductive layers of the first comb teeth are connected to the ground electrode, and at least two conductive layers of the second comb teeth are connected to the same signal electrode, or at least two conductive layers of the second comb teeth are connected to different signal electrodes. In this way, a capacitor can be formed between each conductive layer of the first comb teeth and each conductive layer of the second comb teeth. Exemplarily, a first capacitor can be formed between the first conductive layer and the third conductive layer, and a second capacitor can be formed between the second conductive layer and the fourth conductive layer. Since the number of the first comb teeth and the number of the second comb teeth are both multiple, the comb tooth pair can form multiple first capacitors and multiple second capacitors, multiple first capacitors connected in series, and multiple second capacitors connected in series. The MEMS chip can be a MEMS accelerometer. When the MEMS accelerometer is used to detect the object to be detected, the electronic device including the MEMS chip can be fixed on the object to be detected. When the object to be detected moves, the suspended portion of the support beam also moves, thereby driving the second comb teeth to move. When the object to be detected moves in different directions, the change amount and change trend of the first and second capacitances corresponding to each comb tooth pair may be different. Therefore, the magnitude and direction of the acceleration of the object to be detected can be calculated based on the change amount and change trend of the first and second capacitances corresponding to each comb tooth pair. Moreover, the present application can detect acceleration in three directions based on the change amount and change trend of the first and second capacitances corresponding to each comb tooth pair, thereby improving the integration of the MEMS chip.

[0022] In one possible embodiment, at least two conductive layers of the second teeth of each tooth pair are connected to the ground electrode, that is, the third conductive layer and the fourth conductive layer are both connected to the ground electrode. The first conductive layers of the first teeth of two opposing tooth pairs are respectively connected to different signal electrodes, and the second conductive layers of the first teeth of two opposing tooth pairs are respectively connected to different signal electrodes.

[0023] The first and second conductive layers of the same comb tooth pair are connected to the same signal electrode. The first and second conductive layers of one of the two oppositely arranged comb tooth pairs can receive a first voltage, while the first and second conductive layers of the other comb tooth pair can receive a second voltage. The first and second voltages are equal in magnitude and opposite in direction. A potential difference is formed between the first and third conductive layers, and between the second and fourth conductive layers, thereby driving the mass to resonate under the action of electrostatic force. Therefore, the present application can implement a drive mode for a MEMS gyroscope.

[0024] Moreover, the two opposing comb teeth pairs can form multiple first capacitors, multiple second capacitors, multiple third capacitors, and multiple fourth capacitors. When the second comb teeth rotate in two different directions, the capacitance changes of the multiple first capacitors, multiple second capacitors, multiple third capacitors, and multiple fourth capacitors are different, and the magnitude and direction of the angular velocity can be calculated based on the capacitance changes of these capacitors. Therefore, the present application can detect the magnitude of the angular velocity of the object to be detected in two different directions, thereby improving the integration of the MEMS gyroscope.

[0025] In other embodiments, the first conductive layer and the second conductive layer of the same comb tooth pair are connected to different signal electrodes.

[0026] In another possible embodiment, the first conductive layers of the first comb teeth of the two relatively arranged comb tooth pairs are connected to the ground electrode, and the second conductive layers of the first comb teeth of the two relatively arranged comb tooth pairs are connected to the same signal electrode. The second conductive layer and the third conductive layer of the second comb teeth are respectively connected to different signal electrodes, and the fourth conductive layer of the second comb teeth of each comb tooth pair is connected to the ground electrode. The first conductive layer of the first comb teeth of the two relatively arranged comb tooth pairs is grounded, and the third conductive layer of the second comb teeth is grounded. The second conductive layer of the two relatively arranged comb tooth pairs is used to receive a first voltage, and the fourth conductive layer of the second comb teeth is used to receive a second voltage, and the first voltage is the same in magnitude and opposite in direction to the second voltage. A potential difference can be formed between the first conductive layer and the third conductive layer, and a potential difference can be formed between the second conductive layer and the fourth conductive layer, thereby driving the second comb teeth to resonate under the action of electrostatic force. Therefore, the present application can realize the driving mode of MEMS.

[0027] Moreover, the two opposing comb teeth pairs can form multiple first capacitors, multiple second capacitors, multiple third capacitors, and multiple fourth capacitors. When the second comb teeth rotate in two different directions, the capacitance changes of the multiple first capacitors, multiple second capacitors, multiple third capacitors, and multiple fourth capacitors are different, and the magnitude and direction of the angular velocity can be calculated based on the capacitance changes of these capacitors. Therefore, the present application can detect the magnitude of the angular velocity of the object to be detected in three different directions, thereby improving the integration of the MEMS gyroscope.

[0028] The second aspect of the present application further provides a method for manufacturing a MEMS chip, the method comprising: providing a substrate. Manufacturing at least two conductive layers on the substrate. Etching the at least two conductive layers to form a support beam and a comb tooth pair, wherein the support beam has a suspended portion; the comb tooth pair comprises a plurality of first comb teeth and a plurality of second comb teeth, wherein the plurality of first comb teeth are arranged in a direction perpendicular to the thickness direction of the MEMS chip, and the plurality of second comb teeth are arranged in a direction perpendicular to the thickness direction, and the arrangement direction of the plurality of first comb teeth and the plurality of second comb teeth are the same and are arranged alternately; the first comb teeth comprise at least two conductive layers stacked in the thickness direction, and the second comb teeth comprise at least one conductive layer, wherein the at least one conductive layer of the first comb teeth and the at least one conductive layer of the second comb teeth are arranged in the same layer; etching the substrate to form a base plate.

[0029] Because the first comb teeth include at least two conductive layers, the at least two conductive layers can be separately fabricated using a deposition-first, then-etching process when manufacturing the first comb teeth. The at least one conductive layer of the second comb teeth is provided on the same layer as the at least one conductive layer of the first comb teeth. Therefore, the second comb teeth can be fabricated simultaneously with the first comb teeth. In other words, the first and second comb teeth can be fabricated on the same process platform and in the same step, thereby reducing the complexity of the MEMS chip fabrication process and lowering manufacturing costs.

[0030] In addition, when the MEMS chip is used, different voltage signals can be provided to at least two stacked conductive layers, so that the same MEMS chip can realize multiple different functions, such as driving and sensing, thereby improving the integration of the MEMS chip.

[0031] In a third aspect of the present application, an electronic device is provided, comprising a circuit board and a MEMS chip according to any implementation of the first aspect or a MEMS chip manufactured according to any implementation of the second aspect, wherein the circuit board is electrically connected to the MEMS chip. The electronic device can achieve all the effects of the MEMS chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] FIG1a is a schematic structural diagram of an electronic device according to an embodiment of the present application;

[0034] FIG1b is a schematic structural diagram of an electronic device in another embodiment of the present application;

[0035] FIG2a is a schematic diagram of a planar structure of a comb tooth pair in the related art;

[0036] FIG2 b is a schematic diagram of a cross-sectional structure of a coplanar comb tooth pair in the related art;

[0037] FIG2c is a schematic diagram of a cross-sectional structure of a comb tooth pair in the related art in which the comb tooth pair is a skewed comb tooth pair;

[0038] FIG3 a is a schematic structural diagram of a MEMS chip in an embodiment of the present application when the MEMS chip is a MEMS galvanometer;

[0039] FIG3 b is a cross-sectional view of the first comb tooth pair at AA in FIG3 a ;

[0040] FIG4 is a schematic diagram of a first cross-sectional structure of FIG3a;

[0041] FIG5 is a schematic diagram of a second cross-sectional structure of FIG3a;

[0042] FIG6 is a schematic diagram of a third cross-sectional structure of FIG3a;

[0043] FIG7 is a schematic diagram of a fourth cross-sectional structure of FIG3a;

[0044] FIG8 is a schematic diagram of a fifth cross-sectional structure of FIG3a;

[0045] FIG9 is a schematic structural diagram of a MEMS chip according to an embodiment of the present application when it is a MEMS accelerometer;

[0046] FIG10 a is a cross-sectional view at point BB in FIG9 ;

[0047] FIG10b is a schematic structural diagram of FIG10a after the second comb teeth move upward;

[0048] FIG11 is an equivalent circuit diagram of the structure shown in FIG10a and FIG10b;

[0049] FIG12 is a schematic structural diagram of a MEMS chip according to an embodiment of the present application when the MEMS chip is a MEMS gyroscope;

[0050] FIG13 is a partial enlarged schematic diagram of FIG12;

[0051] FIG14 is a cross-sectional view taken along line DD in FIG13 ;

[0052] FIG15 is a schematic structural diagram of a MEMS chip according to an embodiment of the present application when the MEMS chip is a MEMS gyroscope;

[0053] FIG16 a is a cross-sectional view of the MEMS chip in FIG13 at EE in the first sensing mode;

[0054] FIG16 b is a cross-sectional view of the MEMS chip in FIG13 at EE in the second sensing mode;

[0055] FIG17 is an equivalent circuit diagram of the structure shown in FIG16a and FIG16b;

[0056] FIG18 is a cross-sectional view at FF in FIG15 ;

[0057] FIG19 is a schematic flow chart of a method for manufacturing a MEMS chip according to an embodiment of the present application;

[0058] FIG20 is a schematic diagram showing the specific production steps S71-S75 in the production method shown in FIG19 ;

[0059] FIG. 21 is a schematic diagram showing the specific production steps S76 and S77 in the production method shown in FIG. 19 .

[0060] Icons: 10-MEMS chip; 20-circuit; 21-controller; 22-power supply; 23-voltage adjustment circuit; 24-detection circuit; 25-processor; 30-comb tooth pair; 301-first comb tooth pair; 302-second comb tooth pair; 303-third comb tooth pair; 304-fourth comb tooth pair; 31-first comb tooth; 311-conductive layer; 3111-first conductive layer; 3112-second conductive layer; 3113-third conductive layer; 3114-fourth conductive layer Electrical layer; 312-interlayer insulating layer; 313-upper insulating layer; 314-lower insulating layer; 32-second comb teeth; 40-base plate; 41-hollow area; 42-support frame; 43-fixed part; 44-anchor point; 51-substrate; 52-first insulating layer; 53-first conductive layer; 54-second insulating layer; 55-second conductive layer; 56-third insulating layer; 61-support beam; 611-fixed end; 612-suspended part; 62-lens; 63-mass block. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0062] The term "and / or" herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone, wherein A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (item)" refers to one or more, and "more" refers to two or more. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or multiple.

[0063] In the description and claims of the embodiments of this application, the terms "first" and "second" are used to distinguish different objects, rather than to describe a specific order of objects. For example, the terms "first target object" and "second target object" are used to distinguish different objects, rather than to describe a specific order of objects.

[0064] "Connected", "connected" and similar words are used to express the intercommunication or interaction between different components, which may include direct connection or indirect connection through other components. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. The method, system, product or device is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. "Up", "down", "left", "right" and the like are only used with respect to the orientation of the components in the drawings. These directional terms are relative concepts. They are used for description and clarification relative to the description, which may change accordingly according to the change in the orientation of the components in the drawings.

[0065] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0066] In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more. For example, "multiple processing units" means two or more processing units; "multiple systems" means two or more systems.

[0067] Electronic devices such as mobile phones, electronic watches, and televisions typically include a MEMS chip, a circuit board electrically connected to the MEMS chip, and circuitry electrically connected to the MEMS chip. A MEMS chip can be a MEMS actuator, such as a MEMS resonator, a MEMS micro-mirror, a MEMS optical image stabilization device, a MEMS speaker, or a MEMS switch. A MEMS chip can also be a MEMS sensor, such as a MEMS crystal oscillator, a MEMS accelerometer, a MEMS gyroscope, or a MEMS clock device.

[0068] When the MEMS chip is a MEMS actuator, as shown in FIG1a , the circuit 20 in the electronic device may include a controller 21, a power supply 22, and a voltage adjustment circuit 23. The power supply 22 may be electrically connected to the voltage adjustment circuit 23. The controller 21 may be electrically connected to the voltage adjustment circuit 23. The voltage adjustment circuit 23 may be electrically connected to the MEMS chip 10. In this way, the power supply 22 may send a voltage signal to the MEMS chip 10 via the voltage adjustment circuit 23. The controller 21 may also control the voltage level and phase of the voltage signal sent by the voltage adjustment circuit 23 to the MEMS chip 10 to implement the driving function of the MEMS actuator.

[0069] When the MEMS chip 10 is a MEMS sensor, as shown in FIG1b , the circuit 20 in the electronic device may include, in addition to the controller 21, the power supply 22, and the voltage adjustment circuit 23, a detection circuit 24 and a processor 25. The detection circuit 24 may be electrically connected to the processor 25, and the detection circuit 24 may also be electrically connected to the MEMS chip 10. In this way, the detection circuit 24 can detect the capacitance signal in the MEMS chip 10 and send it to the processor 25. The processor 25 can calculate parameters such as acceleration and angular velocity based on the capacitance signal.

[0070] The MEMS chip 10 includes a comb tooth pair 30 as shown in FIG2a. The comb tooth pair 30 includes a plurality of first comb teeth 31 and a plurality of second comb teeth 32, wherein the first comb teeth 31 can be driving comb teeth and the second comb teeth 32 can be driven comb teeth. Different voltage signals can be provided to the first comb teeth 31 and the second comb teeth 32 to form an electric potential difference between the first comb teeth 31 and the second comb teeth 32, thereby generating an electrostatic force to drive the second comb teeth 32 to generate displacement. Moreover, a capacitor can be formed between the first comb teeth 31 and the second comb teeth 32. As the displacement of the second comb teeth 32 changes, the gap or overlapping area of ​​the capacitor formed between the first comb teeth 31 and the second comb teeth 32 will change, and the capacitance of the capacitor will also change accordingly. Parameters such as acceleration and angular velocity can be calculated based on the change in the capacitance of the capacitor to realize electrostatic induction of the MEMS sensor.

[0071] Depending on whether the driving comb teeth and the driven comb teeth are in the same plane, the comb tooth pair 30 can be divided into a coplanar comb tooth pair and an eccentric comb tooth pair. For example, as shown in Figure 2b, a coplanar comb tooth pair refers to a pair in which the first comb teeth 31 and the second comb teeth 32 are arranged on the same surface, that is, arranged in the same layer. As shown in Figure 2c, an eccentric comb tooth pair refers to a pair in which the first comb teeth 31 and the second comb teeth 32 are arranged on different surfaces, that is, arranged in different layers. Coplanar comb tooth pairs can be used for driving and feedback of in-plane motion. For example, when the first comb teeth 31 and the second comb teeth 32 need to move away from or towards each other, the comb tooth pair 30 can adopt a coplanar comb tooth pair. Occentric comb tooth pairs can be used for driving and feedback of out-of-plane motion. For example, when the first comb teeth 31 and the second comb teeth 32 need to rotate relative to each other, the comb tooth pair 30 can adopt an eccentric comb tooth pair. Of course, coplanar comb tooth pairs can also be used for driving and feedback of out-of-plane motion.

[0072] In the related art, as shown in Figures 2b and 2c, the first comb teeth 31 and the second comb teeth 32 each include a conductive layer 311. For the MEMS chip 10 using a coplanar comb tooth pair, they can be manufactured on the same process platform during production. For the MEMS chip 10 using a non-planar comb tooth pair, since the first comb teeth 31 and the second comb teeth 32 alternate along their arrangement direction and are staggered along the thickness direction, that is, as shown in Figure 2a, the first comb teeth 31 and the second comb teeth 32 alternate along the Y direction and are staggered along the Z direction. Therefore, when manufacturing the MEMS chip 10, it is necessary to manufacture the first comb teeth 31 on the first substrate and the second comb teeth 32 on the second substrate, and then fix the second comb teeth 32 and the second substrate to the first comb teeth 31 and the first substrate by bonding, and then etch away the second substrate to obtain the MEMS chip 10.

[0073] It can be seen that in the related art, the MEMS chip 10 using the coplanar comb tooth pair and the MEMS chip 10 using the skew comb tooth pair have different manufacturing processes and cannot be manufactured on the same process platform.

[0074] Based on this, an embodiment of the present application provides a MEMS chip 10 , and the MEMS chip 10 using a coplanar comb tooth pair and the MEMS chip 10 using a skew comb tooth pair can be manufactured on the same process platform.

[0075] For ease of description, three directions may be defined: a first direction (X direction), a second direction (Y direction), and a third direction (Z direction). The X direction represents the length direction of the MEMS chip 10, the Y direction represents the width direction of the MEMS chip 10, and the Z direction represents the thickness direction of the MEMS chip 10. The X direction, the Y direction, and the Z direction are perpendicular to each other.

[0076] As shown in FIG3 a , the MEMS chip 10 of this embodiment may be a MEMS galvanometer, and may include: a substrate 40 , a support beam 61 , a mirror 62 , and a comb tooth pair 30 .

[0077] As shown in FIG3a , the substrate 40 may include a support frame 42 and a fixing portion 43. The support frame 42 may be a frame-type structure and may have a hollow region 41 formed in the middle thereof.

[0078] As shown in Figure 3a, the support beam 61 includes two fixed ends 611 and a suspended portion 612 located between the two fixed ends 611. The two fixed ends 611 are rotatably connected to the base plate 40, and the suspended portion 612 is suspended above the hollow area 41 of the base plate 40. When subjected to external force, the support beam 61 rotates about its own axis.

[0079] As shown in Figure 3a, the lens 62 is fixed to the support beam 61. In this way, when the support beam 61 rotates around its own axis, it will drive the lens 62 to rotate together, thereby adjusting the incident angle of the light received by the lens 62.

[0080] As shown in Figure 3a, in this embodiment, there can be two fixing portions 43. Both fixing portions 43 are fixed to the substrate 40. Furthermore, the two fixing portions 43 are disposed on opposite sides of the support beam 61. When the MEMS galvanometer is used, the fixing portions 43 always remain fixed in position.

[0081] As shown in Figure 3a, there can be two comb tooth pairs 30, each secured between two fixing portions 43 and the support beam 61. Each comb tooth pair 30 includes a plurality of first comb teeth 31 and a plurality of second comb teeth 32. The plurality of first comb teeth 31 are secured to the fixing portion 43 and arranged along the Y-direction and extend along the X-direction. A gap is provided between each pair of adjacent first comb teeth 31.

[0082] As shown in Figure 3b, the first comb teeth 31 include at least two conductive layers 311 stacked along the Z direction, an interlayer insulating layer 312 located between two adjacent conductive layers 311, an upper insulating layer 313 located above the at least two conductive layers 311, and a lower insulating layer 314 located below the at least two conductive layers 311.

[0083] It can be understood that “above” and “below” are both directions determined by taking the substrate 40 as the bottom of the MEMS chip 10 .

[0084] As shown in FIG3 a , the plurality of second comb teeth 32 are fixed to the suspended portion 612 , arranged along the Y direction and extending along the X direction. A gap exists between each pair of adjacent second comb teeth 32 . It is understood that in other embodiments, the plurality of first comb teeth 31 may be fixed to the suspended portion 612 , and the plurality of second comb teeth 32 may be fixed to the substrate 40 .

[0085] As shown in Figure 3b, the second comb teeth 32 include at least two conductive layers 311 stacked along the Z direction, an interlayer insulating layer 312 located between two adjacent conductive layers 311, an upper insulating layer 313 located above the at least two conductive layers 311, and a lower insulating layer 314 located below the at least two conductive layers 311.

[0086] The plurality of first comb teeth 31 and the plurality of second comb teeth 32 are arranged in the same direction and alternately. For example, as shown in FIG3a , the plurality of first comb teeth 31 and the plurality of second comb teeth 32 are arranged along the Y direction. Furthermore, a second comb tooth 32 is disposed between every two adjacent first comb teeth 31, and a first comb tooth 31 is disposed between every two adjacent second comb teeth 32.

[0087] At least one conductive layer 311 of the first comb teeth 31 is provided on the same layer as at least one conductive layer 311 of the second comb teeth 32. In one possible embodiment, as shown in FIG3b , the comb tooth pair 30 is a coplanar comb tooth pair. In another possible embodiment, as shown in FIG7 , the comb tooth pair 30 is a skew comb tooth pair.

[0088] As shown in FIG3b , when the comb tooth pair 30 is a coplanar comb tooth pair, the first comb tooth 31 and the second comb tooth 32 each include at least two conductive layers 311, and the number of conductive layers 311 of the first comb tooth 31 is the same as the number of conductive layers 311 of the second comb tooth 32. The at least two conductive layers 311 of the first comb tooth 31 and the at least two conductive layers 311 of the second comb tooth 32 are respectively disposed on the same layer. The thickness of the at least two conductive layers 311 of the first comb tooth 31 and the at least two conductive layers 311 of the second comb tooth 32 are respectively the same.

[0089] For example, in this embodiment, as shown in FIG3b , the first comb teeth 31 include two conductive layers 311, which are, from top to bottom, a first conductive layer 3111 and a second conductive layer 3112. The second comb teeth 32 include two conductive layers 311, which are, from top to bottom, a third conductive layer 3113 and a fourth conductive layer 3114. The first conductive layer 3111 and the third conductive layer 3113 are provided on the same layer, while the second conductive layer 3112 and the fourth conductive layer 3114 are provided on the same layer. The thickness of the first conductive layer 3111 is the same as that of the third conductive layer 3113, while the thickness of the second conductive layer 3112 is the same as that of the fourth conductive layer 3114. Thus, when fabricating the comb tooth pair 30, at least two polysilicon layers, an insulating layer between two adjacent polysilicon layers, and insulating layers above and below the two polysilicon layers can be deposited. The two polysilicon layers and the three insulating layers are then etched to form the first comb teeth 31 and the second comb teeth 32. Therefore, the first comb teeth 31 and the second comb teeth 32 can be manufactured on the same process platform, and the first comb teeth 31 and the second comb teeth 32 can be manufactured at the same time.

[0090] Moreover, since in the related art, the first comb teeth 31 and the second comb teeth 32 are manufactured separately, and then the MEMS chip 10 is manufactured by bonding, and the processing error of the bonding process is large, the matching accuracy between the first comb teeth 31 and the second comb teeth 32 of the MEMS chip 10 of the related art is poor, and the yield is low. In this embodiment, the first comb teeth 31 and the second comb teeth 32 can be manufactured on the same process platform, and the first comb teeth 31 and the second comb teeth 32 can be manufactured at the same time, thereby improving the manufacturing accuracy and thus improving the yield. For example, the gap between the first comb teeth 31 and the second comb teeth 32 can be less than 1μm. In this way, after providing voltage signals to the first comb teeth 31 and the second comb teeth 32 respectively, the electrostatic force generated between the first comb teeth 31 and the second comb teeth 32 can be increased.

[0091] Conductors (not shown in FIG3b ) are respectively provided on the first conductive layer 3111 and the second conductive layer 3112, and the MEMS galvanometer may further include a plurality of signal electrodes (not shown in FIG3b ). The first conductive layer 3111 and the second conductive layer 3112 are respectively connected to different signal electrodes through their respective conductors. The signal electrode can be connected to the circuit 20 shown in FIG2b , and the circuit 20 can send a voltage signal to the signal electrode. Thus, the first conductive layer 3111 and the second conductive layer 3112 can receive a voltage signal through the signal electrode. For example, in this embodiment, the first conductive layer 3111 of the first comb tooth 31 can receive a first voltage signal, and the second conductive layer 3112 can receive a second voltage signal.

[0092] Conductors are provided on the third conductive layer 3113 and the fourth conductive layer 3114 of the second comb teeth 32. The third conductive layer 3113 and the second and fourth conductive layers are connected to different signal electrodes via their respective conductors. Thus, voltage signals can be received by the signal electrodes. For example, the third conductive layer 3113 can receive a third voltage signal, and the fourth conductive layer 3114 can receive a fourth voltage signal.

[0093] In FIG3b , the first voltage V1 in the first voltage signal is different from the fourth voltage V4 in the fourth voltage signal, and the second voltage V2 in the second voltage signal is different from the third voltage V3 in the third voltage signal. Thus, the first conductive layer 3111 and the second conductive layer 3112, and the third conductive layer 3113 and the fourth conductive layer 3114 can each receive different voltage signals via different signal electrodes. Similarly, the second conductive layer 3112 and the third conductive layer 3113 can each receive different voltage signals via different signal electrodes. When the first voltage V1 is greater than the fourth voltage V4, a potential difference can be formed between the first conductive layer 3111 and the fourth conductive layer 3114. When the third voltage V3 is also greater than the second voltage V2, a potential difference can also be formed between the third conductive layer 3113 and the second conductive layer 3112. This generates an electrostatic force between the first comb teeth 31 and the second comb teeth 32, thereby driving the second comb teeth 32 to rotate. As shown in Figure 3a, since the second comb teeth 32 are fixed to the suspended portion 612 of the support beam 61, the second comb teeth 32 can drive the support beam 61 to rotate clockwise and counterclockwise, thereby driving the rotation of the lens 62 fixed to the support beam 61. The voltage signal sent by the circuit 20 shown in Figure 2b can be an AC voltage signal. As a result, as the voltage signal changes, the support beam 61 can rotate counterclockwise and clockwise. Therefore, by providing different voltage signals to the at least two stacked conductive layers 311, relative rotation between the first comb teeth 31 and the second comb teeth 32 can be achieved, thereby achieving out-of-plane motion driving.

[0094] Regarding the relationship between the thicknesses of the first conductive layer 3111 and the second conductive layer 3112, in one example, as shown in FIG4 , the thickness of the first conductive layer 3111 is the same as the thickness of the second conductive layer 3112. In this way, the structural parameters of the first conductive layer 3111 and the second conductive layer 3112 are exactly the same. This structure is suitable for a MEMS chip 10 in which the lower insulating layer 314, the second conductive layer 3112, the interlayer insulating layer 312, the first conductive layer 3111, and the upper insulating layer 313 are symmetrical in an up-down manner. In another example, as shown in FIG5 , the thickness of the first conductive layer 3111 is different from the thickness of the second conductive layer 3112. Exemplarily, the thickness of the first conductive layer 3111 is greater than the thickness of the second conductive layer 3112, and correspondingly, the thickness of the third conductive layer 3113 is greater than the thickness of the fourth conductive layer 3114.

[0095] In other embodiments, as shown in FIG6 , the first comb teeth 31 and the second comb teeth 32 each include three conductive layers 311 . Each conductive layer 311 of the first comb teeth 31 is disposed on the same layer and has the same thickness as each conductive layer 311 of the second comb teeth 32 . In this way, a different voltage can be configured for each conductive layer 311 .

[0096] When the comb tooth pair 30 is a skewed comb tooth pair, illustratively, the first comb tooth 31 includes at least two conductive layers 311, and the second comb tooth 32 includes a single conductive layer 311. In one example, as shown in FIG7 , the first comb tooth 31 includes a first conductive layer 3111 and a second conductive layer 3112, and the conductive layer 311 of the second comb tooth 32 is provided on the same layer as the first conductive layer 3111. In another example, as shown in FIG8 , the conductive layer 311 of the second comb tooth 32 is provided on the same layer as the second conductive layer 3112. Thus, when fabricating the comb tooth pair 30, at least two polysilicon layers, an insulating layer between two adjacent polysilicon layers, and insulating layers above and below the two polysilicon layers can be deposited. Subsequently, the two polysilicon layers and the three insulating layers are etched to form the first comb teeth 31 and the second comb teeth 32. Therefore, the first comb teeth 31 and the second comb teeth 32 can be fabricated on the same process platform and simultaneously. Therefore, when the comb tooth pair 30 is a coplanar comb tooth pair or an eccentric comb tooth pair, the comb tooth pair 30 can be manufactured by deposition and etching, so that the MEMS chip 10 using the coplanar comb tooth pair and the MEMS chip 10 using the eccentric comb tooth pair are manufactured based on the same process platform.

[0097] It is understood that in this embodiment, as shown in FIG3 a , the two comb tooth pairs 30 in the MEMS galvanometer have the same structure, and both comb tooth pairs 30 are coplanar comb tooth pairs. In other embodiments, both comb tooth pairs 30 can be skew comb tooth pairs. Alternatively, the structures of the two comb tooth pairs 30 in the MEMS galvanometer can be different. For example, one comb tooth pair 30 is a coplanar comb tooth pair, and the other comb tooth pair 30 is a skew comb tooth pair.

[0098] In other embodiments of the present application, as shown in FIG9 , the MEMS chip 10 may be a MEMS accelerometer. In this embodiment, as shown in FIG9 , the MEMS chip 10 may include a substrate 40, a mass 63, a support beam 61, a comb tooth pair 30, a ground electrode (not shown in FIG9 ), and multiple signal electrodes (not shown in FIG9 ). The substrate 40 includes a fixing portion 43 and an anchor point 44. There may be four fixing portions 43, four support beams 61, and four comb tooth pairs 30. There may be one mass 63, and four anchor points 44. The four fixing portions 43 are arranged in a rectangular array around the periphery of the mass 63. Each comb tooth pair 30 is connected between each fixing portion 43 and the mass 63. The four anchor points 44 are arranged in a rectangular array around the periphery of the mass 63 and located at the four corners of the mass 63. A support beam 61 is connected between each anchor point 44 and the multiple second comb teeth 32 of each comb tooth pair 30. The support beam 61 has a rectangular wave shape. The support beam 61 has a certain degree of flexibility, and the mass block 63 is fixed to the suspended portion 612 of the support beam 61. When the mass block 63 is subjected to force, the mass block 63 is displaced, causing the support beam 61 to deform to a certain extent.

[0099] For ease of description, as shown in FIG9 , the four comb tooth pairs 30 can be respectively named as the first comb tooth pair 301, the second comb tooth pair 302, the third comb tooth pair 303, and the fourth comb tooth pair 304. The first comb tooth pair 301 and the third comb tooth pair 303 are arranged opposite each other, while the second comb tooth pair 302 and the fourth comb tooth pair 304 are arranged opposite each other. Furthermore, the first comb teeth 31 and the second comb teeth 32 in the first comb tooth pair 301 and the third comb tooth pair 303 are arranged along the Y direction, while the first comb teeth 31 and the second comb teeth 32 in the second comb tooth pair 302 and the fourth comb tooth pair 304 are arranged along the X direction.

[0100] As shown in Figure 10a, at least two conductive layers 311 of the first comb teeth 31 are connected to the ground electrode. In this embodiment, at least two conductive layers 311 of the second comb teeth 32 are connected to the same signal electrode. In this way, at least two conductive layers 311 of the second comb teeth 32 can receive the same voltage signal. Therefore, in the circuit 20 shown in Figure 2b, a voltage adjustment circuit 23 can be provided for the at least two conductive layers 311 to output a single voltage signal. In other embodiments, at least two conductive layers 311 of the second comb teeth 32 are connected to different signal electrodes. In this way, at least two conductive layers 311 of the second comb teeth 32 can receive different voltage signals. Therefore, in the circuit 20, multiple different voltage adjustment circuits 23 can be provided for the at least two conductive layers 311, and each of the multiple voltage adjustment circuits 23 is electrically connected to the at least two conductive layers 311 of the second comb teeth 32.

[0101] As shown in Figure 10a, since the first conductive layer 3111 of the first comb tooth 31 is connected to the ground electrode, and the third conductive layer 3113 of the second comb tooth 32 is connected to the signal electrode, when the third conductive layer 3113 receives a voltage signal, the first conductive layer 3111 and the third conductive layer 3113 can form the first capacitor C1 shown in Figure 11. The second conductive layer 3112 is connected to the ground electrode, and the fourth conductive layer 3114 of the second comb tooth 32 is connected to the signal electrode. When the fourth conductive layer 3114 receives a voltage signal, the second conductive layer 3112 and the fourth conductive layer 3114 can form the second capacitor C2 shown in Figure 11. Since there are multiple first comb teeth 31 and multiple second comb teeth 32, the comb tooth pair 30 can form multiple first capacitors C1 and multiple second capacitors C2, with the multiple first capacitors C1 connected in series and the multiple second capacitors C2 connected in series. Each comb tooth pair 30 corresponds to multiple first capacitors and multiple second capacitors. The detection circuit 24 shown in Figure 1b can detect the capacitance signal of each capacitor. That is, in this embodiment, the capacitance signals of the first capacitors C1 of the four comb tooth pairs 30 and the capacitance signals of the second capacitors C2 of the four comb tooth pairs 30 can be detected, so as to calculate the acceleration of the object to be detected based on the capacitance signals.

[0102] In a MEMS accelerometer application, the MEMS accelerometer is fixed to the object to be detected, or an electronic device containing the MEMS accelerometer is fixed to the object to be detected. When the object to be detected moves, the mass block 63 in Figure 9 also moves, and the suspended portion 612 of the support beam 61 also moves, thereby driving the movement of the second comb teeth 32.

[0103] For example, when the object to be detected moves along the X-direction, since the mass block 63 is located on the suspended portion 612 of the support beam 61, the mass block 63 also moves along the X-direction. The second teeth 32 of each of the four tooth pairs 30 move along the X-direction. As a result, the overlapping area between the first teeth 31 and the second teeth 32 of the first tooth pair 301 and the overlapping area between the first teeth 31 and the second teeth 32 of the third tooth pair 303 change. Consequently, the overlapping area of ​​the first capacitor C1 and the second capacitor C2 formed by the first tooth pair 301 and the third tooth pair 303 changes. Consequently, the capacitance of the first capacitor C1 and the second capacitor C2 formed by the first tooth pair 301 and the second tooth pair 302 changes, and the change is large and linear. For the second comb tooth pair 302 and the fourth comb tooth pair 304, the movement of the second comb tooth 32 along the X direction will cause the gap between the first comb tooth 31 and the second comb tooth 32 to change, thereby the first capacitor C1 and the second capacitor C2 formed by the second comb tooth pair 302 and the fourth comb tooth pair 304 also change, but the change is small and presents a nonlinear change.

[0104] When the object to be detected moves along the Y direction, the mass block 63 also moves along the Y direction. In contrast to the case where the object to be detected moves along the X direction, the capacitance changes of the first capacitor C1 and the second capacitor C2 corresponding to the first comb tooth pair 301 and the third comb tooth pair 303 are small and change nonlinearly; while the capacitance changes of the first capacitor C1 and the second capacitor C2 corresponding to the second comb tooth pair 302 and the fourth comb tooth pair 304 are large and change linearly.

[0105] Moreover, when the object to be detected moves along the X direction and / or the Y direction, the capacitance changes of the first capacitor C1 and the second capacitor C2 are the same.

[0106] When the object to be detected moves along the Z direction, the mass block 63 also moves along the Z direction. For example, when the object to be detected moves upward, as shown in Figure 10b, the second comb teeth 32 move upward. Since the overlapping area between the first conductive layer 3111 and the third conductive layer 3113 changes significantly, the capacitance of the first capacitor C1 shown in Figure 11 changes significantly. Since the second conductive layer 3112 overlaps with part of the third conductive layer 3113 and part of the fourth conductive layer 3114, and the second conductive layer 3112 also overlaps with the insulating layer between the third conductive layer 3113 and the fourth conductive layer 3114, the effect of this overlapping area on the second capacitor C2C1 is small and can be ignored. Therefore, the capacitance change of the second capacitor C2 is small. When the object to be detected moves downward, the capacitance change of the first capacitor C1 and the second capacitor C2 is opposite to that when the object to be detected moves upward, that is, the capacitance change of the first capacitor C1 is small, and the capacitance change of the second capacitor C2 is large.

[0107] It can be seen that when the object to be detected moves along the Z direction, the capacitance changes of the first capacitor C1 and the second capacitor C2 are different. However, the capacitance changes of the first capacitor C1 and the second capacitor C2 corresponding to each comb tooth pair 30 are the same.

[0108] Therefore, after obtaining the capacitance signals of the first capacitor C1 and the second capacitor C2 corresponding to each comb tooth pair 30, if the capacitance change of the first capacitor C1 corresponding to each comb tooth pair 30 is the same, and the capacitance change of the second capacitor C2 corresponding to each comb tooth pair 30 is the same, it indicates that the acceleration of the object to be detected is in the Z direction. And further, based on the magnitude relationship between the capacitance change of the first capacitor C1 and the capacitance change of the second capacitor C2, the direction of the acceleration is determined to be upward or downward, and the magnitude of the acceleration is calculated based on the capacitance change of the first capacitor C1 and the capacitance change of the second capacitor C2. If the capacitance change of the first capacitor C1 corresponding to some of the four comb tooth pairs 30 is different, and the capacitance change of the first capacitor C1 corresponding to some of the comb tooth pairs 30 is different, it indicates that the direction of the acceleration of the object to be detected is in the X direction or the Y direction. The direction of the acceleration of the object to be detected can then be determined based on the capacitance change of the first capacitor C1 and the second capacitor C2 corresponding to different comb tooth pairs 30 and whether the change is linear, and the magnitude of the acceleration can be calculated based on the capacitance change of the first capacitor C1 and the second capacitor C2. Therefore, in this embodiment, the MEMS accelerometer can simultaneously detect the acceleration of the object to be detected along the X direction, along the Y direction, and along the Z direction. Since in the related art shown in Figure 2b, the first comb teeth 31 and the second comb teeth 32 both include a conductive layer 311, they can only detect acceleration in two directions. Therefore, the embodiment of the present application can improve the integration of the MEMS accelerometer.

[0109] In other embodiments of the present application, the MEMS chip 10 may be a MEMS gyroscope. As shown in FIG12 , the difference between the embodiment shown in FIG9 lies in the number of anchor points 44 and the structure of the support beam 61. In this embodiment, the number of anchor points 44 is two.

[0110] As shown in Figure 13, the operating modes of the MEMS gyroscope may include a first sensing mode, a second sensing mode, and a driving mode. Regarding the directions of each mode of the MEMS gyroscope, in one possible embodiment, as shown in Figure 13, the driving mode is in the X direction, the first sensing mode is in the Y direction, and the second sensing mode is in the Z direction.

[0111] At least two conductive layers 311 of the second teeth 32 of the first and third tooth pairs 301, 303 are connected to the ground electrode. Specifically, the third and fourth conductive layers 3113, 3114 shown in FIG14 are both connected to the ground electrode. The first conductive layers 3111 of the first and third tooth pairs 301, 303 are each connected to a different signal electrode, and the second conductive layers 3112 of the first and third tooth pairs 301, 303 are each connected to a different signal electrode. That is, as shown in FIG14 , the first conductive layer 3111 of the first and third tooth pairs 301, 303 are connected to different signal electrodes. Thus, the first conductive layer 3111 of the first and third tooth pairs 301, 303 can receive different voltage signals.

[0112] The first conductive layer 3111 and the second conductive layer 3112 of the first comb tooth pair 301 can be connected to the same signal electrode, that is, the first conductive layer 3111 and the second conductive layer 3112 of the first comb tooth pair 301 can receive a first voltage signal through the signal electrode. The first conductive layer 3111 and the second conductive layer 3112 of the third comb tooth pair 303 can be connected to the same signal electrode, that is, the first conductive layer 3111 and the second conductive layer 3112 of the third comb tooth pair 303 can receive a second voltage signal through the signal electrode. The first voltage signal and the second voltage signal are a pair of differential signals, that is, the first voltage V1 in the first voltage signal and the second voltage V2 in the second voltage signal are equal in magnitude and opposite in direction. Thus, as shown in FIG14 , the first voltage V1 is applied to both the first conductive layer 3111 and the second conductive layer 3112 of the first comb tooth pair 301, and the second voltage V2 is applied to both the first conductive layer 3111 and the second conductive layer 3112 of the third comb tooth pair 303.

[0113] As a result, as shown in Figure 14 , a potential difference is formed between the first conductive layer 3111 and the third conductive layer 3113 of the first comb-tooth pair 301, and a potential difference is formed between the third conductive layer 3113 and the first conductive layer 3111 of the third comb-tooth pair 303. Furthermore, a potential difference is formed between the second conductive layer 3112 and the fourth conductive layer 3114 of the first comb-tooth pair 301, and a potential difference is formed between the fourth conductive layer 3114 and the second conductive layer 3112 of the third comb-tooth pair 303. Electrostatic force is generated between the first comb teeth 31 and the second comb teeth 32 of the first comb-tooth pair 301, and between the first comb teeth 31 and the second comb teeth 32 of the third comb-tooth pair 303. This force drives the mass 63 to resonate, thereby achieving a driving mode.

[0114] In the first sensing mode and the second sensing mode, the third conductive layer 3113 and the fourth conductive layer 3114 of the second teeth 32 of the second and fourth comb-tooth pairs 302 and 304 shown in FIG16a are both connected to the ground electrode. The first conductive layers 3111 of the second and fourth comb-tooth pairs 302 and 304 are each connected to a different signal electrode, and the second conductive layers 3112 of the second and fourth comb-tooth pairs 302 and 304 are each connected to a different signal electrode. The first conductive layer 3111 and the second conductive layer 3112 of the second and fourth comb-tooth pairs 302 and 304 are each connected to a different signal electrode. The first conductive layer 3111 and the second conductive layer 3112 of the second and fourth comb-tooth pairs 302 are connected to the same signal electrode, and the first conductive layer 3111 and the second conductive layer 3112 of the fourth comb-tooth pair 304 are connected to the same signal electrode. Thus, the third conductive layer 3113 and the fourth conductive layer 3114 of the second and fourth comb-tooth pairs 302 and 304 are both grounded. The first conductive layer 3111 and the second conductive layer 3112 of the second comb tooth pair 302 can receive a first voltage V1, and the first conductive layer 3111 and the second conductive layer 3112 of the fourth comb tooth pair 304 can receive a second voltage V2. The first voltage V1 and the second voltage V2 are of the same magnitude and opposite in direction.

[0115] The first conductive layer 3111 of the second comb tooth pair 302 and the third conductive layer 3113 form the first capacitor C1 shown in Figure 17, the second conductive layer 3112 of the second comb tooth pair 302 and the fourth conductive layer 3114 form the second capacitor C2 shown in Figure 17, the third conductive layer 3113 of the fourth comb tooth pair 304 and the first semiconductor form the third capacitor C3 shown in Figure 17, and the fourth conductive layer 3114 of the fourth comb tooth pair 304 and the second semiconductor form the fourth capacitor C4 shown in Figure 17.

[0116] In the first sensing mode, when the object to be detected rotates about an axis along the X-direction, the mass 63 also rotates about the axis along the X-direction, and the Coriolis force is in the Y-direction. For example, when the object to be detected rotates clockwise about the axis along the X-direction, the overlapping area between the first capacitor C1 and the fourth capacitor C4 remains substantially unchanged. Therefore, the change in capacitance between the first capacitor C1 and the fourth capacitor C4 remains substantially unchanged. The overlapping area between the second capacitor C2 and the third capacitor C3 decreases. Therefore, the capacitance between the second capacitor C2 and the third capacitor C3 decreases, and the capacitance change is significant. When the object to be detected rotates counterclockwise about the axis along the X-direction, the overlapping area between the second capacitor C2 and the third capacitor C3 remains substantially unchanged. Therefore, the capacitance change between the second capacitor C2 and the third capacitor C3 remains substantially unchanged. The overlapping area between the first capacitor C1 and the fourth capacitor C4 decreases. Therefore, the capacitance between the first capacitor C1 and the fourth capacitor C4 decreases, and the capacitance change is significant.

[0117] In the second sensing mode, when the object to be detected rotates about its axis along the Y direction, the mass 63 also rotates about its axis along the Y direction, and the Coriolis force is exerted in the Z direction. As shown in Figure 16b, the capacitance of the first capacitor C1 of some of the second comb tooth pairs 302 decreases, while the capacitance of the first capacitor C1 of some of the second comb tooth pairs 302 increases. The capacitance of the second capacitor C2 of some of the second comb tooth pairs 302 decreases, while the capacitance of the second capacitor C1 of some of the second comb tooth pairs 302 increases. Similarly, the capacitance of the third capacitor C3 of some of the fourth comb tooth pairs 304 decreases, while the capacitance of the third capacitor C3 of some of the fourth comb tooth pairs 304 increases. The capacitance of the second capacitor C2 of some of the fourth comb tooth pairs 304 decreases, while the capacitance of the second capacitor C2 of some of the fourth comb tooth pairs 304 increases.

[0118] It can be seen that when the object to be detected rotates along the axis of the X direction and around the axis of the Y direction, the capacitance changes of the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 corresponding to each comb tooth pair 30 are different. Therefore, the direction of the angular velocity of the object to be detected and the magnitude of the angular velocity can be determined based on the capacitance changes of the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 of each comb tooth pair 30. Therefore, the embodiment of the present application can realize the detection of angular velocities in two directions. Since in the related art shown in Figure 2b, the first comb tooth 31 and the second comb tooth 32 both include a conductive layer 311, they can only detect acceleration in one direction. Therefore, the embodiment of the present application can improve the integration of the MEMS gyroscope.

[0119] Regarding the directions of the modes of the MEMS gyroscope, in another possible implementation, as shown in FIG15 , the direction of the second sensing mode is the Y direction, the direction of the first sensing mode is the Y direction, and the direction of the driving mode is the Z direction.

[0120] As shown in FIG18 , the first conductive layer 3111 of the first comb tooth pair 301, the first conductive layer 3111 of the third comb tooth pair 303, and the fourth conductive layer 3114 are all connected to the ground electrode. The second conductive layer 3112 of the first comb tooth pair 301 and the second conductive layer 3112 of the third comb tooth pair 303 can be connected to the same signal electrode. Thus, the second conductive layer 3112 of the first comb tooth pair 301 and the second conductive layer 3112 of the third comb tooth pair 303 can receive the same voltage signal. Of course, it is understood that the second conductive layer 3112 of the first comb tooth pair 301 and the second conductive layer 3112 of the third comb tooth pair 303 can be connected to different signal electrodes, and the power supply 22 shown in FIG1 b can provide the same voltage signal to the two different signal electrodes via different voltage adjustment circuits 23.

[0121] The second conductive layer 3112 and the third conductive layer 3113 of the first comb tooth pair 301 are respectively connected to different signal electrodes to receive different voltage signals. For example, the second conductive layer 3112 of the first comb tooth pair 301 and the second conductive layer 3112 of the third comb tooth pair 303 can receive a first voltage signal, while the third conductive layer 3113 can receive a second voltage signal. The first voltage V1 in the first voltage signal and the second voltage V2 in the second voltage signal have the same magnitude and opposite directions.

[0122] In this way, potential differences can be formed between the first conductive layer 3111 and the third conductive layer 3113 of the first comb tooth pair 301, between the third conductive layer 3113 and the first conductive layer 3111 of the third comb tooth pair 303, between the second conductive layer 3112 and the fourth conductive layer 3114 of the first comb tooth pair 301, and between the second conductive layer 3112 and the fourth conductive layer 3114 of the third comb tooth pair 303, thereby driving the second comb tooth 32 to resonate along the Z direction and completing the driving mode of the MEMS gyroscope.

[0123] In the first sensing mode, the third conductive layer 3113 and the fourth conductive layer 3114 are both connected to the ground electrode. The first conductive layer 3111 and the second conductive layer 3112 of the second comb-tooth pair 302 can be connected to the same signal electrode, and the first conductive layer 3111 and the second conductive layer 3112 of the fourth comb-tooth pair 304 can be connected to the same signal electrode. The first conductive layer 3111 of the second comb-tooth pair 302 and the second conductive layer 3112 of the fourth comb-tooth pair 304 can be connected to different signal electrodes. Thus, as shown in FIG16a , the first conductive layer 3111 and the second conductive layer 3112 of the second comb-tooth pair 302 can both receive a first voltage signal, and the first conductive layer 3111 and the second conductive layer 3112 of the fourth comb-tooth pair 304 can both receive a second voltage signal. The first voltage V1 in the first voltage signal and the second voltage V2 in the second voltage signal are of equal magnitude and opposite in direction. When the mass 63 senses in the first sensing mode, the Coriolis force is in the Y direction.

[0124] In the second sensing mode, the third conductive layer 3113 and the fourth conductive layer 3114 are both connected to the ground electrode. The first conductive layer 3111 and the second conductive layer 3112 of the first comb tooth pair 301 can be connected to the same signal electrode, and the first conductive layer 3111 and the second conductive layer 3112 of the third comb tooth pair 303 can be connected to the same signal electrode. The first conductive layer 3111 of the second comb tooth pair 302 and the second conductive layer 3112 of the fourth comb tooth pair 304 can be connected to different signal electrodes. Thus, as shown in FIG14 , the first conductive layer 3111 and the second conductive layer 3112 of the second comb tooth pair 302 can both receive the first voltage signal, and the first conductive layer 3111 and the second conductive layer 3112 of the fourth comb tooth pair 304 can both receive the second voltage signal. The first voltage V1 in the first voltage signal and the second voltage V2 in the second voltage signal are of equal magnitude and opposite in direction. When the mass 63 senses in the first sensing mode, the Coriolis force F is along the X-direction.

[0125] The principle of detecting the direction and magnitude of the angular velocity is the same as that of the embodiment shown in FIG15 . In this embodiment, the detection of angular velocities in two directions can also be achieved, thereby improving the integration of the MEMS gyroscope.

[0126] The embodiment of the present application further provides a method for manufacturing a MEMS chip 10, which is applied to the MEMS chip 10 shown in FIG4 . As shown in FIG19 , the manufacturing method may include:

[0127] S71, providing a substrate 51 and a first insulating layer 52. As shown in FIG20, the substrate 51 and the first insulating layer 52 are stacked.

[0128] S72, as shown in FIG20, a first conductive layer 53 is formed on the first insulating layer 52. The first conductive layer 53 may be made of polysilicon.

[0129] In other embodiments of the present application, the step of providing an SOI substrate 51 may be used instead of steps S71 and S72 in this embodiment.

[0130] S73, forming a second insulating layer 54 on the first conductive layer 53. The second insulating layer 54 can be formed on the side of the first conductive layer 53 facing away from the first insulating layer 52 as shown in FIG. 20 by deposition.

[0131] S74 , as shown in FIG. 20 , a second conductive layer 55 is formed on the second insulating layer 54 .

[0132] S75: Form a third insulating layer 56 on the second conductive layer 55. The third insulating layer 56 can be formed on the side of the second conductive layer 55 away from the second insulating layer 54 as shown in FIG. 20 by deposition.

[0133] S76: Etch the third insulating layer 56, the second conductive layer 55, the second insulating layer 54, the first conductive layer 53, and the first insulating layer 52 to obtain the first comb teeth 31, the second comb teeth 32, and the support beam 61 (not shown in FIG20). As shown in FIG21, a plurality of gaps can be etched along the Z direction on the third insulating layer 56, the second conductive layer 55, the second insulating layer 54, the first conductive layer 53, and the first insulating layer 52 to form the first comb teeth 31 and the second comb teeth 32.

[0134] S77, etching the substrate 51 from the side facing away from the first insulating layer 52 to obtain the base plate 40. As shown in FIG21, the substrate 51 below where the first comb teeth 31, the second comb teeth 32 and the support beam 61 are provided can be etched away to obtain the base plate 40.

[0135] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A micro-electromechanical system (MEMS) chip, characterized in that: include: substrate; a support beam connected to the base plate; A comb tooth pair, the comb tooth pair comprising a plurality of first comb teeth and a plurality of second comb teeth, the plurality of first comb teeth being fixed on the substrate, and the plurality of second comb teeth being fixed on the support beam; or the plurality of first comb teeth being fixed on the support beam, and the plurality of second comb teeth being fixed on the substrate; The arrangement direction of the multiple first comb teeth and the multiple second comb teeth are the same and they are arranged alternately; the first comb teeth include at least two conductive layers stacked along the thickness direction of the MEMS chip, and the second comb teeth include at least one conductive layer, and the at least one conductive layer of the first comb teeth is arranged on the same layer as the at least one conductive layer of the second comb teeth.

2. The MEMS chip according to claim 1, characterized in that: The second comb teeth include at least two conductive layers, the number of conductive layers of the first comb teeth is the same as the number of conductive layers of the second comb teeth, and the at least two conductive layers of the first comb teeth and the at least two conductive layers of the second comb teeth are respectively arranged in the same layer.

3. The MEMS chip according to claim 1, characterized in that: The second comb teeth include a conductive layer, and the at least two conductive layers of the first comb teeth include a first conductive layer and a second conductive layer; The conductive layer of the second comb teeth is disposed on the same layer as the first conductive layer, or the conductive layer of the second comb teeth is disposed on the same layer as the second conductive layer.

4. The MEMS chip according to any one of claims 1 to 3, characterized in that: The thickness of the first conductive layer of the at least two conductive layers of the first comb teeth is the same as the thickness of the second conductive layer.

5. The MEMS chip according to any one of claims 1 to 3, characterized in that: The thickness of the first conductive layer of the at least two conductive layers of the first comb teeth is different from the thickness of the second conductive layer.

6. The MEMS chip according to claim 2, characterized in that: The MEMS chip further includes a plurality of signal electrodes, the first conductive layer of the first comb teeth and the fourth conductive layer of the second comb teeth are respectively connected to different signal electrodes, and the second conductive layer of the first comb teeth and the third conductive layer of the second comb teeth are respectively connected to different signal electrodes; The first conductive layer and the third conductive layer are disposed on the same layer, and the second conductive layer and the fourth conductive layer are disposed on the same layer.

7. The MEMS chip according to any one of claims 1 to 5, characterized in that: The MEMS chip also includes a ground electrode and a plurality of signal electrodes; At least two conductive layers of the first comb teeth are connected to the ground electrode, at least two conductive layers of the second comb teeth are connected to the same signal electrode, or at least two conductive layers of the second comb teeth are connected to different signal electrodes respectively.

8. The MEMS chip according to any one of claims 1 to 5, characterized in that: The MEMS chip also includes a ground electrode and a plurality of signal electrodes; The number of the comb tooth pairs is at least two, wherein two of the comb tooth pairs are arranged opposite to each other; At least two conductive layers of the second comb teeth of each comb tooth pair are connected to the ground electrode; The first conductive layers of the first comb teeth of two relatively arranged comb tooth pairs are respectively connected to different signal electrodes, the second conductive layers of the first comb teeth of two relatively arranged comb tooth pairs are respectively connected to different signal electrodes, and the first conductive layer and the second conductive layer of the same comb tooth pair are connected to the same signal electrode.

9. The MEMS chip according to any one of claims 1 to 5, characterized in that: The MEMS chip also includes a ground electrode and a plurality of signal electrodes; The number of the comb tooth pairs is at least two, wherein two of the comb tooth pairs are arranged opposite to each other; The first conductive layers of the first comb teeth of the two comb tooth pairs arranged opposite to each other are both connected to the ground electrode, and the second conductive layers of the first comb teeth of the two comb tooth pairs arranged opposite to each other are connected to the same signal electrode; The second conductive layer and the third conductive layer of the second comb teeth are respectively connected to different signal electrodes, and the fourth conductive layer of the second comb teeth of each comb tooth pair is connected to the ground electrode; The first conductive layer and the third conductive layer are disposed on the same layer, and the second conductive layer and the fourth conductive layer are disposed on the same layer.

10. A method for manufacturing a MEMS chip, characterized in that: The production method comprises: providing a substrate; forming at least two conductive layers on the substrate; The at least two conductive layers are etched to form a support beam and a comb tooth pair; the comb tooth pair includes a plurality of first comb teeth and a plurality of second comb teeth, and the plurality of first comb teeth and the plurality of second comb teeth are arranged in the same direction and alternately; the first comb teeth include at least two conductive layers stacked in a thickness direction, and the second comb teeth include at least one conductive layer, and the at least one conductive layer of the first comb teeth and the at least one conductive layer of the second comb teeth are arranged in the same layer; The substrate is etched to form a base plate.

11. An electronic device, characterized in that: It comprises a circuit board and the MEMS chip according to any one of claims 1 to 9 or a MEMS chip manufactured by the manufacturing method of claim 10, wherein the circuit board is electrically connected to the MEMS chip.

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