A MEMS double-layer thin film Young's modulus measuring device and method

Abstract

The application discloses a MEMS double-layer thin film Young's modulus measuring device and method, the measuring device comprises three parts, each part comprises a thermal actuator structure, a displacement measuring structure connected with the thermal actuator structure and a double-layer cantilever beam structure; the method comprises the following steps: the thermal actuator structure is used for pushing the displacement measuring structure to move to the direction of the double-layer cantilever beam structure, when the contact electrode of the displacement measuring structure is in contact with the to-be-measured beam of the double-layer cantilever beam structure, the horizontal displacement values s1, s2 and s3 of the three parts are obtained through the readings of the displacement measuring structure respectively; the Young's modulus of the double-layer thin film is obtained by inputting the geometric size of the measuring device, the horizontal displacement values s1, s2 and s3 into an equation and solving the equation; the MEMS double-layer thin film Young's modulus measuring device and method have the advantages of simple operation, low cost and fast measuring speed, and can be used for process line parameter monitoring.

Description

Technical Field

[0001] This invention relates to the field of microelectromechanical systems and their material parameter measurement technology, and in particular to a device and method for measuring the Young's modulus of a MEMS double-layer thin film. Background Technology

[0002] Bilayer thin-film structures are a crucial component of MEMS devices, and the performance and functionality of these devices are closely related to the material parameters of the thin films. Young's modulus is a key parameter describing the mechanical properties of materials. It characterizes the relationship between stress and strain when a material is subjected to tension or compression, reflecting its rigidity or elasticity, and directly affecting the mechanical properties, response speed, and dynamic characteristics of MEMS devices. Therefore, obtaining the Young's modulus of the thin film in MEMS bilayer thin-film structures is of great significance for ensuring the yield of fabrication lines and predicting and optimizing the mechanical behavior of the devices.

[0003] Currently, the main methods for measuring the Young's modulus of MEMS thin film materials include nanoindentation, tympanic membrane method, electrostatic actuation method, and resonance method. Among these, nanoindentation, tympanic membrane method, and resonance method require specialized testing equipment or environments, resulting in high testing costs and slow measurement speeds; the electrostatic actuation method utilizes the unstable phenomenon of attraction, leading to poor repeatability. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for measuring the Young's modulus of MEMS bilayer thin films, which features low measurement cost, high measurement speed, repeatable measurements, and applicability to parameter monitoring in process lines. To achieve the above objective, this invention employs the following technical solution:

[0005] In a first aspect, the present invention provides a MEMS double-layer thin film Young's modulus measuring device, comprising: three parts, each part comprising: a thermal actuator structure, a displacement measuring structure connected to the thermal actuator structure, and a double-layer cantilever beam structure;

[0006] The thermal actuator structure includes: a connecting beam, multiple Z-shaped thermal arms connected to both sides of the connecting beam, a first anchor area, a second anchor area, a first metal electrode, and a second metal electrode; the thermal actuator structure is symmetrically arranged about the connecting beam; the first anchor area and the second anchor area are respectively located on both sides of the connecting beam and connected to the ends of the multiple Z-shaped thermal arms away from the connecting beam; the first metal electrode and the second metal electrode are respectively located in the first anchor area and the second anchor area;

[0007] The displacement measurement structure includes: a moving tooth, a contact electrode, and a first fixed tooth and a second fixed tooth respectively disposed on both sides of the moving tooth; the contact electrode is disposed at one end of the moving tooth.

[0008] The double-layer cantilever beam structure comprises: a to-be-measured beam, a third anchor area connected to the to-be-measured beam, and a third metal electrode; the third metal electrode is arranged in the third anchor area;

[0009] The connecting beam of the thermal actuator structure is connected to one end of the moving tooth away from the contact electrode; a gap exists between the contact electrode of the displacement measurement structure and the to-be-measured beam of the double-layer cantilever beam structure; the to-be-measured beam, the moving tooth, the contact electrode, and the connecting beam are all on the same horizontal axis;

[0010] Among the three parts, the widths of the to-be-measured beams are different.

[0011] Optionally, before the sacrificial layer is released, the horizontal initial spacing between the displacement measurement structure and the double-layer cantilever beam structure is d; wherein the sacrificial layer is arranged between the measurement device and the substrate when the measurement device is manufactured.

[0012] Optionally, the moving tooth comprises a main beam, and a first comb tooth assembly and a second comb tooth assembly symmetrically connected to two sides of the main beam; one end of the main beam is connected to the connecting beam, and the other end is connected to the contact electrode; the first comb tooth assembly and the second comb tooth assembly each comprise m teeth, the width of the teeth is a, and the tooth spacing is b.

[0013] Optionally, the first fixed tooth comprises a first base beam and a comb tooth assembly A; the comb tooth assembly A corresponds to the first comb tooth assembly and comprises m fixed teeth A uniformly distributed on the first base beam; the second fixed tooth comprises a second base beam and a comb tooth assembly B; the comb tooth assembly B corresponds to the second comb tooth assembly and comprises m fixed teeth B uniformly distributed on the second base beam.

[0014] Optionally, the width of the fixed tooth A and the fixed tooth B is a, and the tooth spacing is b+Δ.

[0015] Optionally, in the initial state of the measurement device, the comb tooth assembly A is shifted right by Δ compared to the first comb tooth assembly of the moving tooth, and the comb tooth assembly B is shifted right by (m+1)Δ compared to the second comb tooth assembly of the moving tooth; wherein the right direction is the direction in which the double-layer cantilever beam structure is located.

[0016] Optionally, the to-be-measured beam is composed of a double-layer film; the length of the double-layer film is L, the thickness of the first layer of the double-layer film is h1, the thickness of the second layer is h2, and the width of each layer is less than 5 times the thickness of the layer.

[0017] Optionally, the materials of the connecting beam, the plurality of Z-shaped thermal arms, and the displacement measurement structure are the same as the material of the first layer of the to-be-measured beam, and are all polycrystalline silicon.

[0018] Optionally, the thickness of the contact electrode is h1.

[0019] The second aspect of the present application provides a MEMS double-layer thin film Young's modulus measurement method using the measurement device of the first aspect, comprising:

[0020] Respectively obtain the horizontal displacement values s1, s2 and s3 of the three sections;

[0021] Wherein, the step of obtaining the horizontal displacement value s k of a section comprises:

[0022] Ground the first metal electrode and connect the second metal electrode to a high potential, so that the thermal actuator structure pushes the displacement measurement structure to move towards the double-layer cantilever beam structure;

[0023] Real-time monitor the resistance between the first metal electrode and the third metal electrode, when the contact electrode of the displacement measurement structure contacts the to-be-measured beam of the double-layer cantilever beam structure, the monitored resistance changes from infinity to a finite value, and the horizontal displacement value s k displayed by the displacement measurement structure at this time is read; the horizontal displacement value s k is the moving distance of the kth section of the moving tooth compared with the initial state;

[0024] Based on the geometric size of the measurement device and the horizontal displacement values s1, s2 and s3 of the three sections, the Young's modulus E1 and E2 of the double-layer thin film are obtained by solving the following equation group; the equation group is represented as follows:

[0025]

[0026] Wherein, respectively represent the width of the second layer of the to-be-measured beam in the three sections, and the width of the first layer of the to-be-measured beam in the three sections is ; represents the intrinsic strain difference of the double-layer thin film; L represents the length of the to-be-measured beam, i.e. the length of the double-layer thin film; d represents the horizontal initial spacing between the displacement measurement structure and the double-layer cantilever beam structure.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] The application provides a MEMS double-layer thin film Young's modulus measuring device, which comprises three parts, each part comprising a thermal actuator structure, a displacement measuring structure connected with the thermal actuator structure and a double-layer cantilever beam structure, and the widths of the beams to be measured of the three parts, i.e. the double-layer thin films, are different. The thermal actuator structure is used to push the displacement measuring structure to move towards the double-layer cantilever beam structure, when the contact electrode of the displacement measuring structure contacts with the beam to be measured of the double-layer cantilever beam structure, the horizontal displacement values s1, s2 and s3 of the three parts are obtained through the readings of the displacement measuring structure, the Young's modulus of the double-layer thin film is obtained by bringing the geometric size of the measuring device, the horizontal displacement values s1, s2 and s3 of the three parts into an equation and solving the equation, the MEMS double-layer thin film Young's modulus measuring device and method designed by the application have the advantages of simple operation, low cost, fast measuring speed and high repeatability, and can be used for process line parameter monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Fig. 1 shows a structure schematic diagram of a MEMS double-layer thin film Young's modulus measuring device in an embodiment of the application;

[0030] Figure 2 Fig. 2 shows a flow chart of a MEMS double-layer thin film Young's modulus measuring method in an embodiment of the application;

[0031] In the figure: 201-208, Z-shaped thermal arms; 209, connecting beam; 210, first anchor area; 211, first metal electrode; 212, second anchor area; 213, second metal electrode; 301, movable tooth; 302, first fixed tooth; 303, second fixed tooth; 304, contact electrode; 101, beam to be measured; 101-1, bottom layer of the beam to be measured; 101-2, top layer of the beam to be measured; 102, third anchor area; 103, third metal electrode. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the application will be clearly and completely described with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, but not all the embodiments of the application. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the application of the application or use. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0033] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0034] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] Example 1

[0036] This invention provides a device for measuring the Young's modulus of a MEMS bilayer thin film, such as... Figure 1 As shown, it includes three parts, each of which includes: a thermal actuator structure, a displacement measurement structure connected to the thermal actuator structure, and a double-layer cantilever beam structure;

[0037] The thermal actuator structure includes: a connecting beam 209, multiple Z-shaped thermal arms 201-208 connected to both sides of the connecting beam 209, a first anchor area 210, a second anchor area 212, a first metal electrode 211, and a second metal electrode 213; the thermal actuator structure is symmetrically arranged about the connecting beam 209; the first anchor area 210 and the second anchor area 212 are respectively located on both sides of the connecting beam 209 and connected to the ends of the multiple Z-shaped thermal arms 201-208 away from the connecting beam 209; the first metal electrode 211 and the second metal electrode 213 are respectively located in the first anchor area 210 and the second anchor area 212;

[0038] The displacement measurement structure includes: a movable tooth 301, a contact electrode 304, and a first fixed tooth 302 and a second fixed tooth 303 respectively disposed on both sides of the movable tooth 301; the contact electrode 304 is disposed at one end of the movable tooth 301.

[0039] The double-layer cantilever beam structure comprises: a to-be-measured beam 101, a third anchor area 102 connected with the to-be-measured beam 101, and a third metal electrode 103; the third metal electrode 103 is arranged in the third anchor area 102;

[0040] The connecting beam 209 of the thermal actuator structure is connected with the dynamic tooth 301 away from one end of the contact electrode 304; there is a gap between the contact electrode 304 of the displacement measurement structure and the to-be-measured beam 101 of the double-layer cantilever beam structure; the to-be-measured beam 101, the dynamic tooth 301, the contact electrode 304, and the connecting beam 209 are all on the same horizontal axis.

[0041] In the three sections, the widths of the to-be-measured beams are different, and in this embodiment, the widths of the second layers of the to-be-measured beams in the three sections, i.e., the top layers 101-2 of the to-be-measured beams in the three sections, are respectively .

[0042] Specifically, in this embodiment, the Z-shaped thermal arms 201 and 202 correspond to each other, the Z-shaped thermal arms 203 and 204 correspond to each other, the Z-shaped thermal arms 205 and 206 correspond to each other, and the Z-shaped thermal arms 207 and 208 correspond to each other, and the two corresponding Z-shaped thermal arms are arranged on the two sides of the connecting beam 209; wherein the Z-shaped thermal arms 201, 203, 205, and 207 are on the same side, and the Z-shaped thermal arms 202, 204, 206, and 208 are on the same side; the entire thermal actuator structure is in a mirror-symmetrical structure with the connecting beam 209 as the axis, and the ends of the thermal arms 201, 203, 205, and 207 away from the connecting beam 209 are all connected with the first anchor area 210, and the ends of the thermal arms 202, 204, 206, and 208 away from the connecting beam 209 are all connected with the second anchor area 212.

[0043] In this embodiment, there is no connection relationship between the displacement measurement structure and the double-layer cantilever beam structure, and before the sacrificial layer is released, the horizontal initial distance between the displacement measurement structure and the double-layer cantilever beam structure is accurately set as a distance d, that is, the size of the gap between the contact electrode 304 and the to-be-measured beam 101 is d; this distance d is one of the key factors to ensure that the displacement measurement can be accurately performed; wherein the sacrificial layer is arranged between the measurement device and the substrate when the measurement device is manufactured.

[0044] In this embodiment, the dynamic tooth 301 comprises a main beam, and a first comb tooth assembly and a second comb tooth assembly symmetrically connected on the two sides of the main beam; one end of the main beam is connected with the connecting beam 209, and the other end is connected with the contact electrode 304; the first comb tooth assembly and the second comb tooth assembly each comprise m teeth, the widths of the teeth are all a, and the tooth spacing is b; specifically, in Figure 1 the upper and lower sides of the dynamic tooth 301 are respectively distributed with 9 teeth, and if m=9 as shown in the figure;

[0045] In the embodiment, the first tooth 302 comprises a first base beam and a comb tooth assembly A; the comb tooth assembly A corresponds to the first comb tooth assembly, and the comb tooth assembly A is on the same side of the first base beam as the first comb tooth assembly; the comb tooth assembly A comprises m teeth A evenly distributed on the first base beam; the second tooth 303 comprises a second base beam and a comb tooth assembly B; the comb tooth assembly B corresponds to the second comb tooth assembly, and the comb tooth assembly B is on the same side of the second base beam as the second comb tooth assembly; the comb tooth assembly B comprises m teeth B evenly distributed on the second base beam.

[0046] Specifically, the first tooth 302 and the second tooth 303 are each provided with an anchor area for fixing the first tooth 302 and the second tooth 303 on the substrate.

[0047] Specifically, in the embodiment, the first tooth 302 is located above the movable tooth 301, and the second tooth 303 is located below the movable tooth 301, and the first tooth 302 and the second tooth 303 are respectively provided with 9 teeth A and 9 teeth B. Figure 1

[0048] Specifically, the width of the tooth A and the tooth B is a, and the tooth spacing is b+Δ, which refers to the spacing distance between the tooth A and the tooth A, and the spacing distance between the tooth B and the tooth B.

[0049] Specifically, in the initial state of the measuring device, the comb tooth assembly A is offset to the right by Δ compared with the first comb tooth assembly of the movable tooth 301, and the comb tooth assembly B is offset to the right by (m+1)Δ compared with the second comb tooth assembly of the movable tooth 301; wherein the right direction is the direction of the double-layer cantilever beam structure.

[0050] In the embodiment, the measured beam 101 is composed of a double-layer film; the length of the double-layer film is L; the thickness of the first layer, i.e., the bottom layer 101-1 of the measured beam, in the double-layer film is h1, and the width is The thickness of the second layer, i.e., the top layer 101-2 of the measured beam, is h2, and the width is k represents the kth part, and the width of each layer is less than 5 times the thickness of the layer.

[0051] Specifically, the material of the connecting beam 209, the thermal arm 201-208, the movable tooth 301-303, and the contact electrode 304 is the same as the material of the first layer film of the composite film, i.e., polysilicon. The thickness of the contact electrode 304 is h1.

[0052] Embodiment 2

[0053] Based on the measuring device described in embodiment 1, the embodiment of the application introduces a MEMS double-layer film Young's modulus measurement method, which comprises the following steps:

[0054] ​S01: obtaining horizontal displacement values s1, s2 and s3 of three sections respectively;

[0055] wherein the step of obtaining the horizontal displacement value s k of a section comprises:

[0056] grounding the first metal electrode and connecting the second metal electrode to a high potential, so that the thermal actuator structure pushes the displacement measurement structure to move towards the double-layer cantilever beam structure;

[0057] monitoring the resistance between the first metal electrode and the third metal electrode in real time, when the contact electrode of the displacement measurement structure contacts the beam to be measured of the double-layer cantilever beam structure, the monitored resistance changes from infinity to a finite value, and the horizontal displacement value s k displayed by the displacement measurement structure at this time is read; the horizontal displacement value s k is the moving distance of the moving tooth of the kth section compared with the initial state;

[0058] S02: based on the geometric size of the measuring device and the horizontal displacement values s1, s2 and s3 of the three sections, the Young's modulus E1 and E2 of the double-layer film are obtained by solving the equation set; the equation set is represented as follows:

[0059]

[0060] wherein, respectively represent the width of the second layer of the beam to be measured in the three sections, and the width of the first layer of the beam to be measured in the three sections is ; represents the intrinsic strain difference of the double-layer film; L represents the length of the beam to be measured, i.e. the length of the double-layer film; d represents the horizontal initial distance between the displacement measurement structure and the double-layer cantilever beam structure.

[0061] Specifically, in order to facilitate understanding, the theoretical principle of the measurement method proposed in the application is described:

[0062] In the measuring device mentioned in the application, the second section is taken as an example, i.e. the width of the bottom layer 101-1 of the beam to be measured is , the width of the top layer 101-2 of the beam to be measured is ; the distance z c between the neutral surface of the beam to be measured 101 in the double-layer cantilever beam structure and the lower surface of the beam can be represented as:

[0063]

[0064] wherein, respectively represent the Young's modulus of the first layer and the second layer of the beam to be measured 101, i.e. the Young's modulus of the double-layer film;

[0065] Under the action of the intrinsic stress difference, the beam 101 to be measured is bent, and its equivalent bending stiffness The formula (2) and the formula (3) are substituted into the formula (4), and the following formula (5) can be obtained:

[0066]

[0067] Wherein, I1 and I2 are the cross-sectional moments of inertia of the first layer and the second layer in the double-layer film respectively, Ai is the cross-sectional area of the i-th layer of film, and z represents the distance between a point on the cross section of the film and the lower surface of the beam;

[0068] The bending moment acting on the beam 101 to be measured is:

[0069]

[0070] Wherein, Δε is the intrinsic strain difference of the double-layer film.

[0071] The curvature radius r2 of the beam bending is given by the following formula:

[0072]

[0073] The formula (2) and the formula (3) are substituted into the formula (4), and the following formula (5) can be obtained:

[0074]

[0075] Similarly, the curvature radius r1 of the double-layer cantilever beam structure in the first part and the curvature radius r3 of the double-layer cantilever beam in the third part can be expressed as:

[0076]

[0077] Based on the above principle, the embodiment provides a MEMS double-layer film Young's modulus measurement method, and the specific measurement process is as follows:

[0078] Firstly, the following operations are respectively performed on the three parts:

[0079] The first metal electrode 211 is grounded, the second metal electrode 213 is connected to a high potential, the Z-shaped thermal actuator is electrically heated, at this time, the thermal actuator structure pushes the movable tooth 301 and the contact electrode 304 to move in the direction of the cantilever beam;

[0080] Meanwhile, the resistance between the first metal electrode 211 and the third metal electrode 103 is monitored. When the contact electrode 304 comes into contact with the beam 101 to be measured, the monitored resistance changes from infinity to a finite value, and the horizontal displacement value s k displayed by the vernier (displacement measurement structure) at this time is read; the horizontal displacement value s k is the moving distance of the movable tooth of the k-th part compared with the initial state;​

[0081] For example, if the first tooth of the first comb-tooth assembly in the movable tooth 301 aligns with the first tooth A of the comb-tooth assembly A in the first fixed tooth 302 from left to right at this time, s k = Δ, where k = 1, 2, 3, if the second tooth of the first comb-tooth assembly in the movable tooth 301 aligns with the second tooth A of the comb-tooth assembly A in the first fixed tooth 302 from left to right at this time, s k = 2 Δ, and so on, if the mth tooth of the first comb-tooth assembly in the movable tooth 301 aligns with the mth tooth A of the comb-tooth assembly A in the first fixed tooth 302 from left to right at this time, s k = m Δ; similarly, if the first tooth of the second comb-tooth assembly aligns with the first tooth B of the comb-tooth assembly B in the second fixed tooth 303 from left to right at this time, s k = (m + 1) Δ, if the second tooth of the second comb-tooth assembly aligns with the second tooth B of the comb-tooth assembly B in the second fixed tooth 303 from left to right at this time, s k = (m + 2) Δ, and so on, if the mth tooth of the second comb-tooth assembly aligns with the mth tooth B of the comb-tooth assembly B in the second fixed tooth 303 from left to right at this time, s k = 2m Δ.

[0082] Based on the above steps, the horizontal displacement values s1, s2 and s3 of the three sections are obtained.

[0083] Under the action of the intrinsic stress difference, the double-layer cantilever beam (the measured beam 101) bends and presents an arc shape, and the arc length is the beam length L. Assuming that the arc length of the contact point at which the kth section of the measured beam 101 contacts the contact electrode 304 is L k , according to the geometric relationship of the bent cantilever beam structure, the following can be obtained:

[0084]

[0085] Solving the formula (8) and the formula (9), the curvature radius :

[0086]

[0087] wherein, represents the curvature radius of the kth section of the measured beam 101;

[0088] Substituting the formula (10) into the formula (5), (6) and (7) can obtain

[0089]

[0090] Based on the geometric dimensions of the measuring device and the three partial horizontal displacement values s1, s2 and s3, the Young's moduli E1 and E2 of the double-layer film are calculated by solving the equation set (11).

[0091] The embodiments of the application are described above with reference to the drawings, but the application is not limited to the specific embodiments described above, which are merely illustrative and not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the application without departing from the purpose of the application and the scope protected by the claims.

Claims

1. A MEMS bilayer thin film Young's modulus measuring device, characterized in that, include: The system consists of three parts, each including: a thermal actuator structure, a displacement measurement structure connected to the thermal actuator structure, and a double-layer cantilever beam structure. The thermal actuator structure includes: a connecting beam, multiple Z-shaped thermal arms connected to both sides of the connecting beam, a first anchor area, a second anchor area, a first metal electrode, and a second metal electrode; the thermal actuator structure is symmetrically arranged about the connecting beam; the first anchor area and the second anchor area are respectively located on both sides of the connecting beam and connected to the ends of the multiple Z-shaped thermal arms away from the connecting beam; the first metal electrode and the second metal electrode are respectively located in the first anchor area and the second anchor area; The displacement measurement structure includes: a moving tooth, a contact electrode, and a first fixed tooth and a second fixed tooth respectively disposed on both sides of the moving tooth; the contact electrode is disposed at one end of the moving tooth. The double-layer cantilever beam structure includes: a beam to be tested, a third anchor area connected to the beam to be tested, and a third metal electrode; the third metal electrode is placed in the third anchor area. The connecting beam of the thermal actuator structure is connected to the end of the moving tooth away from the contact electrode; there is a gap between the contact electrode of the displacement measuring structure and the beam to be measured of the double-layer cantilever beam structure; the beam to be measured, the moving tooth, the contact electrode and the connecting beam are all on the same horizontal axis; The widths of the beams to be tested are different in the three sections.

2. The MEMS bilayer thin film Young's modulus measuring device according to claim 1, characterized in that, Before the sacrificial layer is released, the initial horizontal distance between the displacement measuring structure and the double-layer cantilever beam structure is d; wherein, the sacrificial layer is disposed between the measuring device and the substrate during the manufacturing of the measuring device.

3. The MEMS bilayer thin film Young's modulus measuring device according to claim 2, characterized in that, The moving teeth include a main beam, and a first comb tooth assembly and a second comb tooth assembly symmetrically connected on both sides of the main beam; one end of the main beam is connected to a connecting beam, and the other end is connected to a contact electrode; the first comb tooth assembly and the second comb tooth assembly each include m teeth, the width of the teeth is a, and the tooth spacing is b.

4. The MEMS bilayer thin film Young's modulus measuring device according to claim 3, characterized in that, The first fixed tooth includes a first base beam and a comb tooth assembly A; the comb tooth assembly A corresponds to the first comb tooth assembly and includes m fixed teeth A evenly distributed on the first base beam; the second fixed tooth includes a second base beam and a comb tooth assembly B; the comb tooth assembly B corresponds to the second comb tooth assembly and includes m fixed teeth B evenly distributed on the second base beam.

5. The MEMS bilayer thin film Young's modulus measuring device according to claim 4, characterized in that, The width of both fixed teeth A and fixed teeth B is a, and the tooth spacing is b+Δ.

6. The MEMS bilayer thin film Young's modulus measuring device according to claim 5, characterized in that, In the initial state of the measuring device, the comb assembly A is offset to the right by Δ relative to the first comb assembly of the moving teeth, and the comb assembly B is offset to the right by (m+1)Δ relative to the second comb assembly of the moving teeth; wherein, the right direction is the direction in which the double-layer cantilever beam structure is located.

7. The MEMS bilayer thin film Young's modulus measuring device according to claim 6, characterized in that, The beam to be tested is composed of a double-layer film; the length of the double-layer film is L, the thickness of the first layer of the double-layer film is h1, the thickness of the second layer is h2, and the width of each layer is less than 5 times the thickness of the layer.

8. The MEMS bilayer thin film Young's modulus measuring device according to claim 7, characterized in that, The connecting beam, multiple Z-shaped thermal arms, and displacement measurement structure are made of the same material as the first thin film of the beam under test, namely polycrystalline silicon.

9. The MEMS bilayer thin film Young's modulus measuring device according to claim 8, characterized in that, The thickness of the contact electrode is h1.

10. A method for measuring the Young's modulus of a MEMS bilayer thin film using the measuring device described in claim 9, characterized in that, include: The horizontal displacement values ​​s1, s2 and s3 of the three parts are obtained respectively; Among them, the horizontal displacement value s of a certain part is obtained. k The steps include: The first metal electrode is grounded and the second metal electrode is connected to a high potential, causing the thermal actuator structure to push the displacement measurement structure to move toward the double-layer cantilever beam structure. The resistance between the first and third metal electrodes is monitored in real time. When the contact electrode of the displacement measuring structure comes into contact with the beam under test in the double-layer cantilever beam structure, the monitored resistance abruptly changes from infinity to a finite value. The horizontal displacement value s displayed by the displacement measuring structure at this moment is then read. k The horizontal displacement value s k The moving distance of the moving tooth in the kth part compared to the initial state; Based on the geometry of the measuring device and the horizontal displacement values ​​s1, s2, and s3 of the three parts, the Young's moduli E1 and E2 of the bilayer film are obtained by solving the following set of equations; the set of equations is expressed as follows: ； in, These represent the widths of the second layer of the beam under test in the three sections, and the widths of the first layer of the beam under test in the three sections are all... ; The intrinsic strain difference of the double-layer membrane is represented by L; the length of the beam to be measured is represented by d; and the initial horizontal distance between the displacement measurement structure and the double-layer cantilever beam structure is represented by d.

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