1. A method of making an inertial sensor, comprising:

providing a first substrate comprising a first conductive layer;

providing a second substrate, wherein the second substrate comprises a first substrate, and the material of the first substrate is a single crystal material;

bonding the first conductive layer and the first substrate together to form a bonded interface;

forming a movable element including at least a portion of the first substrate.

2. The method of manufacturing an inertial sensor according to claim 1, further comprising manufacturing the first substrate; the preparing the first substrate includes:

preparing a patterned second conductive layer on a second substrate, the patterned second conductive layer including movable element anchor points;

preparing a sacrificial layer on the patterned second conductive layer;

etching a first region of the sacrificial layer to obtain a through hole, wherein the orthographic projection of the first region in the direction vertical to the second substrate falls on the movable element anchor point;

and preparing the first conductive layer on the sacrificial layer, wherein the first conductive layer fills the through hole.

3. The method of manufacturing an inertial sensor according to claim 2, further comprising, before manufacturing the first conductive layer on the sacrificial layer:

etching a second region of the sacrificial layer to obtain a blind hole, wherein the orthographic projection of the second region in the direction vertical to the second substrate falls outside the second conductive layer;

and preparing the first conductive layer on the sacrificial layer, wherein the first conductive layer fills the through hole and also fills the blind hole.

4. The method of manufacturing an inertial sensor according to claim 3, wherein the first conductive layer is manufactured on the sacrificial layer, and the first conductive layer fills the through hole and also fills the blind hole at the same time, and further comprising:

and preparing an anti-adhesion layer in the blind hole.

5. A method of manufacturing an inertial sensor according to any one of claims 1 to 4, characterized in that the first substrate further comprises a sacrificial layer overlying the first conductive layer, the sacrificial layer comprising a through-hole, the first conductive layer filling the through-hole;

the forming a movable element includes:

thinning the second base plate to the rest part of the first substrate;

performing patterned etching on the rest part of the first substrate surface until the sacrificial layer is exposed;

and etching off part of the sacrificial layer to form the movable element.

6. The method of manufacturing an inertial sensor according to claim 2, wherein the first conductive layer is manufactured on the sacrificial layer, and after the first conductive layer fills the through hole, the method further comprises;

and etching downwards from the surface of the first conductive layer to form a groove until the patterned second conductive layer and the first conductive layer in the through hole are exposed, so as to obtain the patterned first conductive layer.

7. A method of manufacturing an inertial sensor according to claim 1 or 6, characterized in that the first substrate comprises a recess which extends through the first conductive layer to form the patterned first conductive layer;

the forming a movable element includes:

thinning the second base plate to the rest part of the first substrate;

and carrying out patterned etching from the rest part of the first substrate surface until the groove is exposed so as to form the movable element.

8. A method of manufacturing an inertial sensor according to any one of claims 4 to 7, wherein the first and second conductive layers are of the same material; and/or

The second substrate is a silicon wafer.

9. An inertial sensor, comprising: a movable element including a first substrate and a first conductive layer which are stacked, a material of the first substrate being a single crystal material.

10. An inertial sensor according to claim 9, further comprising a second conductive layer on a side of the first conductive layer facing away from the first substrate, with a gap between the second conductive layer and the first conductive layer.

11. An inertial sensor according to claim 9, characterised in that the material of the first and second conductive layers is the same.

12. An inertial sensor according to claim 9, characterised in that the surface of the first conductive layer facing the second conductive layer is provided with a stop structure for limiting the displacement of the movable element in a direction perpendicular to the second conductive layer.

13. An inertial sensor according to claim 12, characterised in that the orthographic projection of the stop structure in a direction perpendicular to the second conductive layer falls outside the second conductive layer.

14. An inertial sensor according to claim 12 or 13, characterised in that the surface of the first conductive layer facing the second conductive layer is provided with a projection forming the stop structure.

15. An inertial sensor according to claim 12, characterized in that the surface of the stop structure has an anti-adhesion layer.

16. An inertial sensor according to claim 15, characterized in that the material of the adhesion-preventing layer comprises silicon nitride.

17. An inertial sensor according to claim 10, characterised in that the surface of the first conductive layer facing the second conductive layer is provided with a protrusion; the second conductive layer includes a movable element anchor, the protrusion being connected with the movable element anchor.

18. An inertial sensor according to claim 17, characterised in that the second conductive layer further comprises two fixed electrodes, one on each opposite side of the movable element anchor point.

Background

Conventional MEMS inertial sensors have 2 processing schemes, one is epitaxial polysilicon and one is SOI technology to fabricate the moveable structure. The epitaxial polysilicon is prepared by depositing a sacrificial layer, depositing a polysilicon seed layer, and performing epitaxy, wherein the sacrificial layer is released through VHF. The stress control requirement of the process on the epitaxial polysilicon is higher, and if the stress control is not good, the performance consistency of mass-produced inertial sensors is poor. SOI technology is achieved by means of silicon/silicon oxide bonding, where the requirements on the quality of the bond are high and where the electrical interconnection of the lower and upper layers of silicon oxide is challenging due to the non-conducting nature of the silicon oxide layer.

Content of application

In view of this, embodiments of the present application are directed to providing an inertial sensor and a method for manufacturing the same, so as to solve the problems of poor performance uniformity and high electrical interconnection difficulty of mass-produced inertial sensors in the prior art.

In a first aspect, the present application provides a method for manufacturing an inertial sensor, including: providing a first substrate, wherein the first substrate comprises a first conducting layer; providing a second substrate, wherein the second substrate comprises a first substrate, and the material of the first substrate is a single crystal material; bonding the first conductive layer and the first substrate together to form a bonded interface; a movable element is formed, the movable element including at least a portion of the first substrate. In this way, the movable element can be formed on the basis of the first substrate, and since the first substrate is a single crystal material, the thickness thereof is precisely controllable, thereby ensuring uniform performance of mass-produced inertial sensors.

In one embodiment, the method of manufacturing an inertial sensor further comprises preparing a first substrate. Preparing the first substrate includes: preparing a patterned second conductive layer on a second substrate, the patterned second conductive layer including movable element anchor points; preparing a sacrificial layer on the patterned second conductive layer; etching a first region of the sacrificial layer to obtain a through hole, wherein the orthographic projection of the first region in the direction vertical to the second substrate falls on the anchor point of the movable element; and preparing a first conductive layer on the sacrificial layer, wherein the first conductive layer fills the through hole. According to the first substrate obtained in the way, the first conductive layer has a complete structure, and a bonding interface formed subsequently is ensured to be firmer.

In one embodiment, before the preparing the first conductive layer on the sacrificial layer, the method further comprises: etching a second region of the sacrificial layer to obtain a blind hole, wherein the orthographic projection of the second region in the direction vertical to the second substrate falls outside the second conductive layer; and preparing a first conductive layer on the sacrificial layer, wherein the first conductive layer is used for filling the through hole and simultaneously filling the blind hole. In this way, a stopper structure can be formed on the surface of the movable element facing the fixed electrode, thereby avoiding the movable element from being damaged due to excessive vibration amplitude of the movable element.

In one embodiment, before the preparing the first conductive layer on the sacrificial layer, the method further comprises: and preparing an anti-adhesion layer in the blind hole. Therefore, the blocking structure can be prevented from being adhered when contacting with the film layer below the blocking structure, and the reliability of the product is improved.

In one embodiment, the first substrate further includes a sacrificial layer overlapping the first conductive layer, the sacrificial layer including a via, the first conductive layer filling the via. Forming a movable element, the movable element including at least a portion of the first substrate including: thinning the second base plate to the rest part of the first substrate; carrying out patterned etching on the rest part of the first substrate surface until the sacrificial layer is exposed; portions of the sacrificial layer are etched away to form the movable element. According to the embodiment, the unpatterned first conductive layer and the first substrate are combined to form the combination interface, so that the strength of the combination interface is ensured, the risk of fragment in the process of patterning the surface of the first substrate is reduced, and the product yield is improved.

In one embodiment, after preparing the first conductive layer on the sacrificial layer and filling the via hole with the first conductive layer, the method further includes: and etching downwards from the surface of the first conductive layer to form a groove until the patterned second conductive layer and the first conductive layer in the through hole are exposed, so as to obtain the patterned first conductive layer. In the first substrate obtained in this way, the first conductive layer has a patterned structure, which is beneficial to releasing stress.

In one embodiment, the first substrate includes a groove that penetrates the first conductive layer to form a patterned first conductive layer. Forming a movable element, the movable element including at least a portion of the first substrate including: thinning the second base plate to the rest part of the first substrate; and carrying out patterned etching from the rest part of the first substrate surface until the groove is exposed so as to form the movable element. According to the embodiment, the patterned first conductive layer and the first substrate are combined to form the combined interface, so that stress generated in the surface combining process can be released through the patterned structure, and the product yield is improved.

In one embodiment, the first conductive layer and the second conductive layer are the same material; and/or the second substrate is a silicon wafer. Since the bonding force between the same materials is good, by preparing the first conductive layer and the second conductive layer using the same materials, it is possible to ensure a more secure interface between the two.

A second aspect of the present application provides an inertial sensor comprising: and a movable element including a first substrate and a first conductive layer which are stacked, the first substrate being made of a single crystal material.

In one embodiment, the inertial sensor further comprises a second conductive layer located on a side of the first conductive layer facing away from the first substrate, with a gap between the second conductive layer and the first conductive layer.

In one embodiment, the first conductive layer and the second conductive layer are the same material.

In one embodiment, a surface of the first conductive layer facing the second conductive layer is provided with a stop structure for limiting displacement of the movable element in a direction perpendicular to the second conductive layer.

In one embodiment, an orthographic projection of the stop structure in a direction perpendicular to the second conductive layer falls outside the second conductive layer.

In one embodiment, a surface of the first conductive layer facing the second conductive layer is provided with a protrusion, the protrusion forming a stop structure.

In one embodiment, the surface of the stop structure has an anti-adhesion layer.

In one embodiment, the material of the anti-blocking layer comprises silicon nitride.

In one embodiment, a surface of the first conductive layer facing the second conductive layer is provided with a protrusion; the second conductive layer includes a movable element anchor point, and the protruding portion is connected to the movable element anchor point.

In one embodiment, the second conductive layer further includes two fixed electrodes respectively located on opposite sides of the movable element anchor point.

According to the inertial sensor and the preparation method thereof, an interface combination mode is used for replacing an epitaxial polysilicon mode, so that the stress of a combination interface is reduced, and the performance consistency of the mass-produced inertial sensor is improved. Meanwhile, compared with the SOI technology in the prior art, the first conducting layer and the single crystal material layer are respectively used as the interface combination part, namely, the electrical connection is realized while the interface combination is carried out, and the electrical interconnection difficulty is reduced.

Drawings

Fig. 1 is a flowchart of a method for manufacturing an inertial sensor according to a first embodiment of the present disclosure.

Fig. 2a to fig. 2g are schematic structural diagrams of devices formed in the process of executing the method for manufacturing the inertial sensor shown in fig. 1 according to the first embodiment of the present application.

Fig. 3a to 3c are schematic structural diagrams of devices formed in the process of executing the method for manufacturing the inertial sensor shown in fig. 1 according to the second embodiment of the present application.

Fig. 4a and 4b are schematic structural diagrams of a device formed in the process of executing the method for manufacturing the inertial sensor shown in fig. 1 according to the third embodiment of the present application.

Fig. 5a to 5c are schematic structural diagrams of devices formed in the process of executing the method for manufacturing the inertial sensor shown in fig. 1 according to the fourth embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 1 is a flowchart of a method for manufacturing an inertial sensor according to a first embodiment of the present disclosure. As shown in fig. 1, a method 100 for manufacturing an inertial sensor includes:

step S110, a first substrate is provided, and the first substrate includes a first conductive layer.

Referring to fig. 2a, the first substrate 10 includes at least one film layer including a first conductive layer 11. The first conductive layer 11 is located on the top layer or the bottom layer of the first substrate 10, and may be a patterned film layer or an unpatterned complete film layer. The material of the first conductive layer 11 includes a metal or a semiconductor. In one example, the material of the first conductive layer 11 is polysilicon.

Step S120, providing a second substrate, where the second substrate includes a first substrate, and the first substrate is made of a single crystal material.

Referring to fig. 2b, the second substrate 20 includes at least one film layer including a first substrate 21 of a single crystalline material. The first substrate 21 is positioned on the top or bottom layer of the first base plate 10. In one example, the first substrate 21 is a monocrystalline silicon wafer, typically 725 microns thick. The monocrystalline silicon wafer has good crystallization quality, the consistency of the whole wafer is good, and the yield is easier to ensure in batch production. In one example, the first substrate 21 is a low resistance sheet having a resistivity of about 0.01 ohm/cm.

Step S130, the first conductive layer and the first substrate are bonded together to form a bonding interface. The thickness of first conductive layer 11 is negligible with respect to the thickness of first substrate 21.

Referring to fig. 2c, the first conductive layer 11 and the first substrate 21 may be bonded together by bonding or soldering, etc. to form a bonding interface. In one example, the second substrate 20 is a low resistance single crystal silicon wafer. In this case, the second substrate 20 needs to be doped before performing the step S130 to ensure the electrical conductivity.

Step S140, referring to fig. 2g, forms a movable element 210, the movable element 210 comprising at least a portion of the first substrate 21. At least a portion of the first substrate 21 includes the complete first substrate 21 or the first substrate 21 remaining after thinning.

According to the preparation method of the inertial sensor provided by the embodiment, an interface bonding mode is used for replacing an epitaxial polysilicon mode, so that the stress of a bonding interface is reduced, and the performance consistency of mass-produced inertial sensors is improved. Meanwhile, compared with the SOI technology in the prior art, the first conducting layer and the single crystal material layer are respectively used as the interface combination part, namely, the electrical connection is realized while the interface combination is carried out, and the electrical interconnection difficulty is reduced.

The method 100 for manufacturing an inertial sensor according to fig. 1 is suitable for manufacturing an acceleration sensor, including an X-axis acceleration sensor, a Y-axis acceleration sensor, a Z-axis acceleration sensor, or any combination thereof; or a gyroscope, this application is not limiting.

The following describes a manufacturing process of the inertial sensor shown in fig. 1 by taking a Z-axis acceleration sensor as an example and taking four specific embodiments as examples, and referring to the relevant drawings.

In one embodiment, refer to fig. 2a to 2 g.

In a first step, a first substrate is prepared.

First, referring to fig. 2a, a patterned second conductive layer 13 is formed on a second substrate 15, the patterned second conductive layer 13 includes a fixed electrode 131 and a movable element anchor 132, i.e., the second conductive layer 13 has a patterned structure. The movable element anchor 132 is used to connect to the first conductive layer 11 through the support post to support the movable element. The fixed electrodes 131 include two electrodes, one on each side of the movable element anchor 132, for example, the left and right sides as viewed in fig. 2 a. In one example, the second conductive layer 13 further includes fixed electrode anchors 133 for connecting the fixed electrodes 131 to form lead-out terminals at appropriate positions. The material of the second substrate 15 may be glass or semiconductor. In one example, the second substrate 15 is a silicon wafer. The second conductive layer 13 may be a metal layer or a semiconductor layer. In one example, the second conductive layer 13 is a polysilicon layer. In one embodiment, the buffer layer 14 is formed on the surface of the second substrate 15 before the second conductive layer 13 is prepared. The buffer layer 14 is, for example, a silicon dioxide layer.

Next, with continued reference to fig. 2a, a sacrificial layer 12 is prepared on the patterned second conductive layer 13. The sacrificial layer 12 may be formed by thermal growth or deposition, the sacrificial layer 12 being, for example, a silicon dioxide layer.

Continuing to refer to fig. 2a, a via 120 is etched in a first region of the sacrificial layer 12, an orthographic projection of the first region in a direction perpendicular to the second substrate 15 being located on the movable element anchor 132. Thus, movable element anchor 132 is exposed through hole 120.

Then, with continued reference to fig. 2a, a first conductive layer 11 is formed on the sacrificial layer 12, and the first conductive layer 11 fills the via 120 to form a protrusion, which serves as a support post and a movable element anchor 132 connection. In one example, the first conductive layer 11 and the second conductive layer 13 are the same material, for example, polysilicon. Since the same material has the same properties, forming the first conductive layer 11 and the second conductive layer 13 using the same material can make the adhesion between the two stronger and ensure a more stable structure. In one embodiment, after obtaining the first conductive layer 11, the first conductive layer 11 is further subjected to a planarization process, for example, the planarization process is performed on the first conductive layer 11 by a chemical mechanical polishing method, so as to prepare for subsequent surface bonding with the second substrate 20. Thus, the first substrate 10 is obtained.

In a second step, referring to fig. 2b, a silicon wafer is provided as the second substrate 20. In this case, the second base plate 20 includes only the first substrate 21, and the thickness thereof is precisely controllable.

Third, referring to fig. 2c, the first conductive layer 11 and the first substrate 21 are bonded together to form a bonding interface. For example, a wafer bonder is used to pre-bond the first conductive layer 11 of the first substrate 10 and the first substrate 21 of the second substrate 20 by van der waals force; and then, annealing the pre-bonded device in an environment of 600-1100 ℃ to realize fusion bonding, thereby obtaining a high-quality bonding interface. In this case, the first conductive layer 11 and the first substrate 21 are electrically connected by bonding, and compared with the connection realized by the growth process, the reliability is higher without a stress gradient problem caused by the influence of the crystal orientation of crystal grains and the like. Meanwhile, the first conductive layer 11 and the first substrate 21 are both of a whole-layer structure and are not patterned, so that the bonding quality is further ensured, and the method is suitable for mass production.

Fourthly, forming the movable element.

Specifically, referring to fig. 2d, the second substrate 20 is thinned to the remaining portion of the first substrate 21. In the present embodiment, the second base plate 20 includes only the first substrate 21, and therefore this step corresponds to thinning the first substrate 21 to the remaining portion of the first substrate 21. In one example, the thickness of the first substrate 21 remaining after thinning is 20 to 80 microns.

Next, referring to fig. 2e, a wiring layer 30 is prepared on the surface of the remaining portion of the first substrate 21. The wiring layer 30 is used to make electrical connections and/or form a seal ring. For example, in the present embodiment, the wiring layer 30 includes a seal ring 311 and an extraction terminal 312. The number of lead terminals 312 is plural, and the movable element 210, the left fixed electrode 131, and the right fixed electrode 131 are connected to each other.

Specifically, a metal layer is prepared on the surface of the remaining portion of the first substrate 21 using a deposition process, and the metal layer is patterned through a photolithography and etching process to form the wiring layer 30. For example, a photoresist layer may be formed on the metal layer, and the thickness of the photoresist layer may be 1 to 3 micrometers; patterning the metal layer by photoetching and corrosion processes; the photoresist layer may then be removed by means of an oxygen plasma. In one example, the material of the metal layer comprises aluminum, which is about 1 micron thick and may be formed by sputtering.

Next, referring to fig. 2f, a patterned etching is performed from the remaining portion of the surface of the first substrate 21 to expose the sacrificial layer 12. The patterned structure is subsequently released to form the movable element 210. The patterned structure corresponds to the patterned structure in the second conductive layer 13. For example, as shown in fig. 2f, the second conductive layer 13 includes two fixed electrodes 131 respectively located on the left and right sides of the movable element anchor 132. Accordingly, the patterned structure of the movable element 210 includes two movable electrodes respectively corresponding to the two fixed electrodes 131, and the two movable electrodes are integrally formed.

Then, referring to fig. 2g, a portion of the sacrificial layer 12 is etched away, so that the stacked remaining first substrate 21 and the first conductive layer 11 with the patterned structure form a movable element 210. A portion of the sacrificial layer 12 is etched away, for example, using hydrofluoric acid vapor, to form the movable element 210.

Thus, a Z-axis acceleration sensor was obtained. The working principle is as follows: the capacitance is changed by the distance between the movable electrode in the movable element 210 and the fixed electrode 131, and the acceleration in the Z-axis direction is measured by the change in capacitance.

Embodiment two, refer to fig. 3a to 3 c. The difference between the second embodiment and the first embodiment is only that, as can be seen from comparing fig. 2g and fig. 3c, the present embodiment further includes a step of forming a stopper structure 211 below the movable element 210, wherein the stopper structure is used for limiting the displacement of the movable element 210 in the direction perpendicular to the second conductive layer 13.

Specifically, referring to fig. 3a, in the first step of preparing the first substrate 10, after the sacrificial layer 12 is prepared, that is, before the first conductive layer 11 is prepared on the sacrificial layer 12, the method further includes: the blind via 121 is obtained by etching a second region of the sacrificial layer 12, and an orthographic projection of the second region in a direction perpendicular to the second substrate 15 falls outside the second conductive layer 13.

In this case, referring to fig. 3b, the first conductive layer 11 is prepared on the sacrificial layer 12, and the first conductive layer 11 fills the through hole 120 and also fills the blind hole 121.

The second step, the third step and the fourth step in the first embodiment are executed next, and the Z-axis acceleration sensor shown in fig. 3c is obtained. The movable element 210 includes a first conductive layer 11 and a first substrate 21, which are stacked, and a surface of the first conductive layer 11 facing away from the first substrate 21 has a protrusion to form a stopper structure 211 for preventing the movable element 210 from vibrating too much to cause damage.

Example three, see fig. 4a and 4 b. The difference between the third embodiment and the second embodiment is only that, as can be seen by comparing fig. 3c and fig. 4b, the present embodiment further comprises a step of forming an anti-adhesion layer 212 on the lower surface of the stopper 211.

Specifically, referring to fig. 4a, before the first conductive layer 11 is prepared on the sacrificial layer 12 in the first step, that is, after the blind via 121 is obtained, the method further includes: an anti-adhesion layer 212 is prepared within blind hole 121. The thickness of the adhesion prevention layer 212 is smaller than the height of the blind hole 121. In one example, the material of the anti-blocking layer 212 is silicon nitride. Then, the first conductive layer 11 is prepared, and the first conductive layer 11 fills the remaining portions of the through hole 120 and the blind via 121.

The second step, the third step and the fourth step in the first embodiment are executed next, and the Z-axis acceleration sensor shown in fig. 4b is obtained. The movable element 210 includes a first conductive layer 11 and a first substrate 21 stacked, a surface of the first conductive layer 11 facing away from the first substrate 21 has a protrusion to form a stopper 211, and a surface of the stopper 211 has an adhesion preventing layer 212. The anti-blocking layer 212 serves to prevent the stop structure 210 from sticking to the underlying film layer, such as the cushioning layer 14, when in contact therewith.

Example four, see fig. 5a and 5 c. The difference between the fourth embodiment and the first embodiment is the structure of the first substrate. Accordingly, the process of forming the movable element 210 in the fourth step is also different.

Specifically, in a first step, a first substrate is prepared.

The steps of preparing the first substrate 30 are substantially the same as the process in the first embodiment, except that after the device structure shown in fig. 2a is obtained, the method further includes: referring to fig. 5a, a groove Q is formed by etching from the surface of the first conductive layer 11 downward to expose the patterned second conductive layer 13 and the first conductive layer 11 in the through hole, so as to obtain the patterned first conductive layer 11. Thus, the first substrate 30 is obtained.

The second and third steps in the first embodiment are then performed to obtain the device shown in fig. 5b, in which the first conductive layer 11 and the first substrate 21 form a bonding interface by surface bonding. The groove Q in the first base plate 30 forms a cavity between the first conductive layer 11 and the first substrate 21. In the third step, since the first conductive layer 11 is a patterned structure in this embodiment, the patterned structure can release stress during bonding, so that the uniformity of the final device is better than that of the first embodiment in which the bonding is performed by using an unpatterned whole layer structure.

Fourthly, forming the movable element.

Specifically, referring to fig. 5c, the second substrate 20 is thinned to the remaining portion of the first substrate 21. In the present embodiment, the second base plate 20 includes only the first substrate 21, and therefore this step corresponds to thinning the first substrate 21 to the remaining portion of the first substrate 21.

Next, with continuing reference to fig. 5c, a wiring layer 30 is prepared on the remaining portion of the surface of the first substrate 21. The step of preparing the wiring layer 30 is the same as the step of preparing the wiring layer 30 in the first embodiment, and is not described again here.

Next, with reference to fig. 5c, a patterned etching is performed from the surface of the remaining portion of the first substrate 21 to expose the groove Q, so as to form the movable element 210, where the movable element 210 includes the thinned first substrate 21.

Thus, a Z-axis acceleration sensor was obtained.

The application also provides an inertial sensor. As shown in fig. 2g, 3c, 4b and 5c, the inertial sensor includes a movable element 210, and the movable element 210 includes a first substrate 21 and a first conductive layer 11, which are stacked. The material of the first substrate 21 and the material of the first conductive layer 11 are different. In one example, the material of the first substrate 21 is a single crystal material, and the material of the first conductive layer 11 is a polysilicon material.

In one embodiment, as shown in fig. 2g, 3c and 4b, the inertial sensor further comprises a second conductive layer 13, the second conductive layer 13 being located on a side of the first conductive layer 11 facing away from the first substrate 21, the second conductive layer 13 and the first conductive layer 11 having a gap therebetween and being connected by support posts. The second conductive layer 13 includes two fixed electrodes 131 and movable element anchors 132, and the two fixed electrodes 131 are respectively located on the left and right sides of the movable element anchors 132. The movable element 210 includes two movable electrodes respectively facing the two fixed electrodes 131 to form a capacitive structure.

In one embodiment, the first conductive layer 11 and the second conductive layer 13 are the same material, for example, both polysilicon. Because the same material has the same property, the bonding force between the two film layers is larger, and the reliability is ensured.

In one embodiment, as shown in fig. 3c and 4b, the surface of the first conductive layer 11 facing the second conductive layer 13 includes a stop structure 211, and an orthographic projection of the stop structure 211 in a direction perpendicular to the second conductive layer 13 falls outside the second conductive layer 13. In one embodiment, as shown in FIG. 4b, the surface of stop 211 has an anti-adhesion layer 212. In one example, the material of the anti-blocking layer 212 is silicon nitride.

The inertial sensor provided by the embodiment of the present application can be obtained by using the preparation method provided by any one of the embodiments, and details which are not specifically described in the product embodiment may refer to a part of the preparation method, which is not described herein again.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

It should be understood that the terms "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used for clearly explaining the technical solutions, and are not used for limiting the protection scope of the present application.

The foregoing description has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit embodiments of the application to the form disclosed herein. While a number of example aspects and embodiments have been discussed above, those of skill in the art will recognize certain variations, modifications, alterations, additions and sub-combinations thereof.