MEMS double-layer film Young modulus measuring device and method

Abstract

The invention discloses an MEMS double-layer film Young modulus measuring device and method, the measuring device comprises three subsections, and each subsection 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 steps that a thermal actuator structure is used for pushing a displacement measurement structure to move towards a double-layer cantilever beam structure, and when a contact electrode of the displacement measurement structure makes contact with a to-be-measured beam of the double-layer cantilever beam structure, horizontal displacement values s1, s2 and s3 of three subsections are obtained through readings of the displacement measurement structure; the physical dimension and the horizontal displacement values s1, s2 and s3 of the measuring device are substituted into an equation to solve the Young modulus of the double-layer film; the MEMS double-layer film Young modulus measuring device and method have the advantages of being easy to operate, low in cost and high in measuring speed, and can be used for parameter monitoring of a process line.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-electromechanical systems and material parameter measurement thereof, and in particular to a device and method for measuring Young's modulus of a MEMS double-layer film. Background Art

[0002] The double-layer film structure is an important component of MEMS devices. The performance and functional realization of the device are closely related to the material parameters of the film. Young's modulus is one of the key parameters to describe the mechanical properties of materials. It characterizes the relationship between stress and strain when the material is stretched or compressed, reflects the rigidity or elasticity of the material, and directly affects the mechanical properties, response speed and dynamic characteristics of MEMS devices. Therefore, in the MEMS double-layer film structure, obtaining the Young's modulus of the film is of great significance for ensuring the yield of the processing line, predicting and optimizing the mechanical behavior of the device.

[0003] At present, the main methods for measuring the Young's modulus of MEMS thin film materials include nanoindentation method, tympanic membrane method, electrostatic execution method, resonance method, etc. Among them, nanoindentation method, tympanic membrane method and resonance method require special test equipment or test environment, with high test cost and slow measurement speed; electrostatic execution method uses the unstable phenomenon of attraction and has poor repeatability. Summary of the invention

[0004] The purpose of the present invention is to provide a MEMS double-layer film Young's modulus measurement device and method, which has low measurement cost, fast measurement speed, repeatable measurement, and can be used for parameter monitoring of process lines. To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a MEMS double-layer film Young's modulus measuring device, comprising: three subdivisions, each subdivision 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 comprises: a connecting beam, a plurality of Z-shaped thermal arms connected to both sides of the connecting beam, a first anchoring area, a second anchoring area, a first metal electrode and a second metal electrode; the thermal actuator structure is symmetrically arranged with respect to the connecting beam; the first anchoring area and the second anchoring area are respectively arranged on both sides of the connecting beam and connected to one end of the plurality of Z-shaped thermal arms away from the connecting beam; the first metal electrode and the second metal electrode are respectively arranged in the first anchoring area and the second anchoring area;

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

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

[0009] 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 measurement 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;

[0010] Among them, the widths of the beams to be measured in the three sections 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 disposed between the measurement device and the substrate when the measurement device is manufactured.

[0012] Optionally, the movable tooth includes 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 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 include m teeth, the width of the teeth is a, and the tooth spacing is b.

[0013] Optionally, the first fixed teeth include 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 teeth include 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.

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

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

[0016] Optionally, the beam to be measured 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 material of the connecting beam, the multiple Z-shaped thermal arms, and the displacement measurement structure is the same as the material of the first thin film layer of the beam to be measured, which is polycrystalline silicon.

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

[0019] In a second aspect, the present invention provides a method for measuring the Young's modulus of a MEMS double-layer film using the measuring device described in the first aspect, comprising:

[0020] Obtain the horizontal displacement values ​​s1, s2 and s3 of the three divisions respectively;

[0021] Among them, get the horizontal displacement value s of a certain division k The steps include:

[0022] The first metal electrode is grounded, and the second metal electrode is connected to a high potential, so that the thermal actuator structure pushes the displacement measurement structure to move in the direction of the double-layer cantilever beam structure;

[0023] The resistance between the first metal electrode and the third metal electrode is monitored 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. The horizontal displacement value s displayed by the displacement measurement structure at this time is read. k ; The horizontal displacement value s k is the moving distance of the moving tooth of the kth division compared to the initial state;

[0024] Based on the geometric dimensions of the measuring device and the horizontal displacement values ​​s1, s2 and s3 of the three parts, the Young's modulus E1 and E2 of the double-layer film are obtained by solving the following set of equations; the set of equations is expressed as follows:

[0025]

[0026] in, Respectively represent the width of the second layer of the beam to be measured in the three divisions, and the width of the first layer of the beam to be measured in the three divisions is ; represents the intrinsic strain difference of the double-layer film; L represents the length of the beam to be measured, that is, the length of the double-layer 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 invention has the following beneficial effects:

[0028] The present invention provides a MEMS double-layer film Young's modulus measuring device, including three divisions, each of which includes a thermal actuator structure, a displacement measuring structure connected to the thermal actuator structure, and a double-layer cantilever beam structure; the widths of the beams to be measured, i.e., the double-layer film, of the three divisions are different. The thermal actuator structure is used to push the displacement measuring structure to move in the direction of the double-layer cantilever beam structure, and when the contact electrode of the displacement measuring structure contacts the beam to be measured of the double-layer cantilever beam structure, the horizontal displacement values ​​s1, s2, and s3 of the three divisions are obtained respectively through the readings of the displacement measuring structure; the geometric dimensions of the measuring device, the horizontal displacement values ​​s1, s2, and s3 of the three divisions are substituted into the equation to solve and obtain the Young's modulus of the double-layer film; the MEMS double-layer film Young's modulus measuring device and method designed by the present invention have the advantages of simple operation, low cost, fast measurement speed, and high repeatability, and can be used for parameter monitoring of process lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure shows a schematic structural diagram of a MEMS double-layer film Young's modulus measuring device in one embodiment of the present invention;

[0030] Figure 2 Shown is a flow chart of a method for measuring Young's modulus of a MEMS double-layer film in one embodiment of the present invention;

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

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may also include different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0034] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0035] Example 1

[0036] The embodiment of the present invention introduces a MEMS double-layer film Young's modulus measurement device, such as Figure 1 As shown, it includes: three divisions, each division 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 comprises: a connecting beam 209, a plurality of Z-shaped thermal arms 201-208 connected to both sides of the connecting beam 209, a first anchoring area 210, a second anchoring area 212, a first metal electrode 211 and a second metal electrode 213; the thermal actuator structure is symmetrically arranged with respect to the connecting beam 209; the first anchoring area 210 and the second anchoring area 212 are respectively arranged on both sides of the connecting beam 209, and connected to one end of the plurality of 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 arranged in the first anchoring area 210 and the second anchoring area 212;

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

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

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

[0041] Among them, the widths of the beams to be measured in the three sections are different. In this embodiment, the widths of the second layer of the beams to be measured in the three sections, that is, the top layers 101-2 of the beams to be measured in the three sections are respectively .

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

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

[0044] In this embodiment, the movable tooth 301 includes 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 the connecting beam 209, and the other end is connected to the contact electrode 304; 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; specifically, Figure 1 There are 9 teeth distributed on the upper and lower sides of the middle moving tooth 301, if m=9 as shown in the figure;

[0045] In this embodiment, the first fixed teeth 302 include 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 and the first comb tooth assembly are on the same side of the first base beam; the comb tooth assembly A includes m fixed teeth A evenly distributed on the first base beam; the second fixed teeth 303 include 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 and the second comb tooth assembly are on the same side of the second base beam; the comb tooth assembly B includes m fixed teeth B evenly distributed on the second base beam;

[0046] Specifically, anchor regions are provided on the first fixed tooth 302 and the second fixed tooth 303 for fixing the first fixed tooth 302 and the second fixed tooth 303 on the substrate.

[0047] Specifically, in Figure 1 The first fixed teeth 302 are located above the moving teeth 301, and the second fixed teeth 303 are located below the moving teeth 301, and 9 fixed teeth A and 9 fixed teeth B are respectively provided on the first fixed teeth 302 and the second fixed teeth 303;

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

[0049] Specifically, in the initial state of the measuring device, the comb tooth assembly A is offset to the right by Δ compared to 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 to 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 this embodiment, the beam to be measured 101 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, that is, the bottom layer 101-1 of the beam to be measured is h1, and the width is The thickness of the second layer, i.e. the top layer 101-2 of the beam to be tested, is h2, and the width is , k represents the kth division, and the width of each layer is less than 5 times the thickness of the layer.

[0051] Specifically, the materials of the connecting beam 209, the hot arms 201-208, the moving and fixed teeth 301-303, and the contact electrode 304 are the same as those of the beam 101 to be tested, that is, the first layer of the composite film, which are all polysilicon. The thickness of the contact electrode 304 is h1.

[0052] Example 2

[0053] Based on the measuring device described in Example 1, the embodiment of the present invention introduces a method for measuring the Young's modulus of a MEMS double-layer film, including:

[0054] S01: Obtain the horizontal displacement values ​​s1, s2 and s3 of the three divisions respectively;

[0055] Among them, get the horizontal displacement value s of a certain division k The steps include:

[0056] The first metal electrode is grounded, and the second metal electrode is connected to a high potential, so that the thermal actuator structure pushes the displacement measurement structure to move in the direction of the double-layer cantilever beam structure;

[0057] The resistance between the first metal electrode and the third metal electrode is monitored 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. The horizontal displacement value s displayed by the displacement measurement structure at this time is read. k ; The horizontal displacement value s k is the moving distance of the moving tooth of the kth division compared to the initial state;

[0058] S02: Based on the geometric dimensions of the measuring device and the horizontal displacement values ​​s1, s2 and s3 of the three parts, the Young's modulus E1 and E2 of the double-layer film are obtained by solving the equation group; the equation group is expressed as follows:

[0059]

[0060] in, Respectively represent the width of the second layer of the beam to be measured in the three divisions, and the width of the first layer of the beam to be measured in the three divisions is ; represents the intrinsic strain difference of the double-layer film; L represents the length of the beam to be measured, that is, the length of the double-layer film; d represents the horizontal initial spacing between the displacement measurement structure and the double-layer cantilever beam structure.

[0061] Specifically, for ease of understanding, the theoretical principle of the measurement method proposed in the present invention is explained:

[0062] Taking the second section of the measuring device mentioned in the present invention as an example, 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 tested is ; The distance z between the neutral plane of the beam 101 to be measured and the lower surface of the beam in the double-layer cantilever beam structure c It can be expressed as:

[0063]

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

[0065] Under the action of the intrinsic stress difference, the beam 101 to be tested bends, and its equivalent bending stiffness is It can be calculated using the following formula:

[0066]

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

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

[0069]

[0070] Here, Δε is the intrinsic strain difference of the bilayer film.

[0071] The radius of curvature, r2, of a beam bend is given by:

[0072]

[0073] Substituting formula (2) and formula (3) into formula (4), we can get:

[0074]

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

[0076]

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

[0078] First, perform the following operations on each of the three divisions:

[0079] The first metal electrode 211 is grounded, and the second metal electrode 213 is connected to a high potential, so as to electrically heat the Z-type thermal actuator. At this time, the thermal actuator structure pushes the movable tooth 301 and the contact electrode 304 to move toward the cantilever beam.

[0080] At the same time, the resistance between the first metal electrode 211 and the third metal electrode 103 is monitored. When the contact electrode 304 contacts the beam 101 to be measured, the monitored resistance changes from infinity to a finite value, and the horizontal displacement value s displayed by the vernier ruler (displacement measurement structure) is read. k ; The horizontal displacement value s k is the moving distance of the moving tooth of the kth division compared to the initial state;

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

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

[0083] Under the action of the intrinsic stress difference, the double-layer cantilever beam (beam to be tested 101) bends and presents an arc shape. The arc length is the beam length L. Assume that the arc length of the contact point where the k-th section beam to be tested 101 contacts the contact electrode 304 is L k , according to the geometric relationship of the cantilever beam structure after bending, we can get:

[0084]

[0085] Solving formula (8) and formula (9), we can get the radius of curvature :

[0086]

[0087] in, represents the curvature radius of the k-th section of the beam 101 to be tested;

[0088] Substituting formula (10) into formulas (5), (6) and (7) yields

[0089]

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

[0091] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A MEMS double-layer film Young's modulus measurement device, characterized in that: include: Three divisions, each division includes: a thermal actuator structure, a displacement measuring structure connected to the thermal actuator structure, and a double-layer cantilever beam structure; The thermal actuator structure comprises: a connecting beam, a plurality of Z-shaped thermal arms connected to both sides of the connecting beam, a first anchoring area, a second anchoring area, a first metal electrode and a second metal electrode; the thermal actuator structure is symmetrically arranged with respect to the connecting beam; the first anchoring area and the second anchoring area are respectively arranged on both sides of the connecting beam and connected to one end of the plurality of Z-shaped thermal arms away from the connecting beam; the first metal electrode and the second metal electrode are respectively arranged in the first anchoring area and the second anchoring area; The displacement measurement structure comprises: a moving tooth, a contact electrode, and a first fixed tooth and a second fixed tooth respectively arranged on both sides of the moving tooth; the contact electrode is arranged at one end of the moving tooth; The double-layer cantilever beam structure comprises: a beam to be measured, a third anchoring area connected to the beam to be measured, and a third metal electrode; the third metal electrode is placed in the third anchoring 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 measurement 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; Among them, the widths of the beams to be measured in the three sections are different.

2. The MEMS double-layer film Young's modulus measuring device according to claim 1, characterized in that: Before the sacrificial layer is released, the horizontal initial distance 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.

3. The MEMS double-layer film Young's modulus measuring device according to claim 2, characterized in that: The movable 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 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 include m teeth, the width of the teeth is a, and the tooth spacing is b.

4. The MEMS double-layer film Young's modulus measuring device according to claim 3, characterized in that: The first fixed teeth include 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 teeth include 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 double-layer film Young's modulus measuring device according to claim 4, characterized in that: The widths of the fixed teeth A and B are both a, and the tooth spacings are both b+Δ.

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

7. The MEMS double-layer film Young's modulus measuring device according to claim 6, characterized in that: The beam to be measured 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 double-layer film Young's modulus measuring device according to claim 7, characterized in that: The materials of the connecting beam, the multiple Z-shaped thermal arms, and the displacement measurement structure are the same as the material of the first layer of the thin film of the beam to be measured, which are all polycrystalline silicon.

9. The MEMS double-layer 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 Young's modulus of a MEMS double-layer film using the measuring device of claim 9, characterized in that: include: Obtain the horizontal displacement values ​​s1, s2 and s3 of the three divisions respectively; Among them, get the horizontal displacement value s of a certain division k The steps include: The first metal electrode is grounded, and the second metal electrode is connected to a high potential, so that the thermal actuator structure pushes the displacement measurement structure to move in the direction of the double-layer cantilever beam structure; The resistance between the first metal electrode and the third metal electrode is monitored 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. The horizontal displacement value s displayed by the displacement measurement structure at this time is read. k ; The horizontal displacement value s k is the moving distance of the moving tooth of the kth division compared to the initial state; Based on the geometric dimensions of the measuring device and the horizontal displacement values ​​s1, s2 and s3 of the three parts, the Young's modulus E1 and E2 of the double-layer film are obtained by solving the following set of equations; the set of equations is expressed as follows: ； in, Respectively represent the width of the second layer of the beam to be measured in the three divisions, and the width of the first layer of the beam to be measured in the three divisions is ; represents the intrinsic strain difference of the double-layer film; L represents the length of the beam to be measured, that is, the length of the double-layer film; d represents the horizontal initial spacing between the displacement measurement structure and the double-layer cantilever beam structure.

Images