CN210183543U - MEMS structure - Google Patents
MEMS structure Download PDFInfo
- Publication number
- CN210183543U CN210183543U CN201921698665.9U CN201921698665U CN210183543U CN 210183543 U CN210183543 U CN 210183543U CN 201921698665 U CN201921698665 U CN 201921698665U CN 210183543 U CN210183543 U CN 210183543U
- Authority
- CN
- China
- Prior art keywords
- electrode layer
- layer
- cavity
- mems structure
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The application discloses MEMS structure includes: a substrate having a cavity; the piezoelectric composite vibration layer comprises a fixed end and a free end, the fixed end is connected to the position above the substrate material on the first side of the cavity, the free end is hung above the substrate material on the second side of the cavity, the piezoelectric composite vibration layer covers the cavity, and the first side and the second side of the cavity are oppositely arranged; a sound-leakage-prevention stopper located above the free end and blocking deflection of the free end of the piezoelectric composite vibration layer. Based on the MEMS structure provided by the application, the limitation on the piezoelectric composite vibration layer can be realized, the probability that the vibration beam is bent greatly and broken is reduced, and the reliability of the MEMS structure is improved. On the other hand, sound leakage prevention limiting parts increase sound resistance and reduce low-frequency sound leakage.
Description
Technical Field
The present application relates to the field of semiconductor technology, and more particularly, to a MEMS (micro electro mechanical Systems, abbreviated as micro electro mechanical Systems) structure.
Background
MEMS microphones (microphones) mainly include both capacitive type and piezoelectric type. The MEMS piezoelectric microphone is prepared by utilizing a micro-electro-mechanical system technology and a piezoelectric film technology, and has small size, small volume and good consistency due to the adoption of semiconductor planar technology, bulk silicon processing technology and other technologies. Meanwhile, compared with a condenser microphone, the microphone also has the advantages of no need of bias voltage, large working temperature range, dust prevention, water prevention and the like.
However, when the vibration beam of the MEMS piezoelectric microphone is bent greatly due to too much sound pressure or other external reasons, the vibration beam is broken and damaged easily, thereby affecting the reliability of the MEMS piezoelectric microphone. In addition, the conventional MEMS piezoelectric microphone is also prone to low-frequency sound leakage.
Aiming at the problem of low reliability of the MEMS piezoelectric microphone in the related art, no effective solution is provided at present.
SUMMERY OF THE UTILITY MODEL
The MEMS structure is provided for solving the problem that the reliability of the MEMS piezoelectric microphone in the related art is low, and the reliability of the MEMS piezoelectric microphone can be improved.
The technical scheme of the application is realized as follows:
according to one aspect of the present application, there is provided a MEMS structure comprising a substrate having a cavity; the piezoelectric composite vibration layer comprises a fixed end and a free end, the fixed end is connected to the position above the substrate material on the first side of the cavity, the free end is hung above the substrate material on the second side of the cavity, the piezoelectric composite vibration layer covers the cavity, and the first side and the second side of the cavity are oppositely arranged; a sound-leakage-prevention stopper located above the free end and blocking deflection of the free end of the piezoelectric composite vibration layer.
Wherein the piezoelectric composite vibration layer includes: a first electrode layer formed over the substrate; a first piezoelectric layer formed over the first electrode layer; a second electrode layer formed over the first piezoelectric layer.
Wherein the piezoelectric composite vibration layer further includes: a vibration support layer formed between the substrate and the first electrode layer.
Wherein the piezoelectric composite vibration layer further includes: a second piezoelectric layer formed over the second electrode layer; a third electrode layer formed over the second piezoelectric layer.
The MEMS structure further comprises a connecting support layer positioned above the substrate, and the fixed end is connected with the substrate through the connecting support layer.
Wherein the thickness of the substrate material of the first side of the cavity is greater than the thickness of the substrate material of the second side of the cavity, the fixed end is directly connected to and above the substrate material of the first side of the cavity, and the free end is suspended above the substrate material of the second side of the cavity.
Wherein the free end is located between the substrate and the sound leakage preventing stopper, and the free end and the sound leakage preventing stopper have an overlapping region in a vertical direction.
Wherein the sound leakage prevention limiting piece surrounds the free end of the piezoelectric composite vibration layer; or the sound leakage prevention limiting piece only covers a part of the free end of the piezoelectric composite vibration layer.
The first electrode layer and the second electrode layer are respectively provided with a plurality of partitions which are isolated from each other, the material of the first electrode layer and the material of the second electrode layer in the same partition form an electrode layer pair, and the electrode layer pairs in different partitions are sequentially connected in series.
The first electrode layer, the second electrode layer and the third electrode layer are provided with at least two mutually isolated partitions, the material of the first electrode layer and the material of the third electrode layer in the same partition are electrically connected and then form an electrode layer pair with the material of the second electrode layer, and the electrode layer pairs among the partitions are sequentially connected in series.
The first electrode layer, the second electrode layer and the third electrode layer are provided with at least two mutually isolated partitions, the material of the first electrode layer and the material of the second electrode layer in the same partition form a first electrode layer pair, the material of the second electrode layer and the material of the third electrode layer form a second electrode layer pair, the first electrode layer pair and the second electrode layer pair form an electrode layer string after being connected in series, and the electrode layer strings between the partitions are connected in series in sequence.
Based on the MEMS structure provided by the application, the limitation on the piezoelectric composite vibration layer can be realized, the probability that the vibration beam is broken due to large-amplitude bending is reduced, and the reliability of the MEMS structure is improved. On the other hand, sound leakage prevention limiting parts increase sound resistance and reduce low-frequency sound leakage.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Various aspects of the present application may be better understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale and are used for illustration purposes only. In fact, the dimensions of the various elements may be arbitrarily increased or decreased for clarity of discussion.
FIG. 1 is a cross-sectional schematic view of a MEMS structure according to some embodiments of the present application;
FIG. 2 is a cross-sectional schematic view of a MEMS structure according to some embodiments of the present application;
FIG. 3 is a top view of a MEMS structure according to some embodiments 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 that can be derived from the embodiments given herein by a person of ordinary skill in the art are intended to be within the scope of the present disclosure.
The following disclosure provides many different embodiments, or examples, for implementing different features of the application. Specific examples of components and arrangements are described below to simplify the present application. These are, of course, merely examples and are not intended to be limiting. For example, the dimensions of the elements are not limited to the disclosed ranges or values, but may depend on the process conditions and/or desired properties of the device. Further, in the following description, forming a first feature over or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. Various components may be arbitrarily drawn in different sizes for simplicity and clarity.
Furthermore, spatially relative terms such as "below … … (beneath)", "below … … (below)", "lower (lower)", "above … … (above)", "upper (upper)" and the like may be used herein to describe the relationship of one element or component to another (or other) element or component as illustrated in the figures for ease of description. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, the term "made from … …" can mean "including" or "consisting of … …".
According to an embodiment of the present application, a MEMS structure is provided, which is applied to a microphone or a microphone and has good reliability.
As shown in fig. 1 and 2, the MEMS structure according to the embodiment of the present application includes a substrate 10, a piezoelectric composite vibration layer 20, and a sound leakage preventing stopper 30. The respective components will be specifically described below.
The substrate 10 comprises silicon or any suitable silicon-based compound or derivative (e.g., silicon wafer, SOI, SiO)2Polysilicon on Si). The substrate 10 has a cavity 11, and the cavity 11 may be formed using DRIE (deep reactive ion etching) or wet etching.
A piezoelectric composite vibration layer 20 is formed over the substrate 10. The piezoelectric composite vibration layer 20 includes a fixed end a connected to above the substrate material on the first side of the cavity 11 and a free end B suspended above the substrate material on the second side of the cavity 11, the first and second sides of the cavity 11 being disposed opposite to each other, the piezoelectric composite vibration layer 20 covering the cavity 11. In other words, the piezoelectric composite vibration layer 20 forms a cantilever structure, and thus vibrates under the sound pressure.
Forming the cantilever beam structure having the fixed end a and the free end B may include two methods. One way is to form a connection support layer 40 above the substrate 10, the thickness of the substrate material at the first side of the cavity 11 being equal to the thickness of the substrate material at the second side of the cavity 11, the fixed end a being connected to the substrate 10 through the connection support layer 40. The material for the connection support layer 40 includes parylene, polyimide, SiN, SiO2And polysilicon. Another method is to etch a part of the substrate 10 or to apply a sacrificial layer such that the thickness of the substrate material at a first side of the cavity 11 is larger than the thickness of the substrate material at a second side of the cavity 11, the fixed end a being directly connected to the substrate material at the first side of the cavity 11 such that the free end B is suspended above the substrate material at the second side of the cavity 11.
The piezoelectric composite vibration layer 20 includes a vibration support layer 21, a first electrode layer 22, a first piezoelectric layer 23, and a second electrode layer 24. The vibration support layer 21 is formed over the substrate 10, the first electrode layer 22 is formed over the vibration support layer 21, the first piezoelectric layer 23 is formed over the first electrode layer 22, and the second electrode layer 24 is formed over the first piezoelectric layer 23. The vibration support layer 21 includes silicon nitride (Si)3N4) Silicon oxide, monocrystalline silicon, polycrystalline silicon, or other suitable support material. In consideration of the problem of controlling the stress of the vibration support layer 21, the vibration support layer 21 may be provided in a multi-layer structure to reduce the stress. The method of forming the vibration support layer 21 includes a thermal oxidation method or a chemical vapor deposition method. The first electrode layer 22, the first piezoelectric layer 23, and the second electrode layer 24 constitute a piezoelectric composite layer. The first piezoelectric layer 23 can convert the applied pressure into a voltage, and the first electrode layer 22 and the second electrode layer 24 can transmit the generated voltage to other integrated circuit devices. In some embodiments, the material of the first piezoelectric layer 23 includes zinc oxide, aluminum nitride, organic piezoelectric film, lead zirconate titanate (PZT), calcium titaniumOne or more layers of a mineral piezoelectric film, or other suitable material. The method of forming the first piezoelectric layer 23 includes magnetron sputtering or other suitable methods. The material of the first electrode layer 22 and the second electrode layer 24 includes aluminum, gold, platinum, molybdenum, titanium, chromium, and composite films composed of these or other suitable materials. Methods of forming the first electrode layer 22 and the second electrode layer 24 include physical vapor deposition or other suitable methods.
In some embodiments, in embodiments where the vibration support layer 21 is not provided, a second piezoelectric layer (not shown in the drawings) and a third electrode layer (not shown in the drawings) may be sequentially formed over the second electrode layer 24. Therefore, the piezoelectric composite layer of the MEMS structure has the first electrode layer 22, the first piezoelectric layer 23, the second electrode layer 24, the second piezoelectric layer, and the third electrode layer, thereby forming a bimorph structure, and improving the piezoelectric conversion efficiency of the MEMS structure. The material of the second piezoelectric layer includes one or more layers of zinc oxide, aluminum nitride, an organic piezoelectric film, lead zirconate titanate (PZT), a perovskite-type piezoelectric film, or other suitable materials. The material and formation method of the second piezoelectric layer may be the same as or different from those of the first piezoelectric layer 23. The material of the third electrode layer includes aluminum, gold, platinum, molybdenum, titanium, chromium, and a composite film composed of these materials or other suitable materials. The material and the formation method of the third electrode layer may be the same as or different from those of the first electrode layer 22.
The sound leakage prevention stopper 30 is located above the free end B and blocks the deflection of the free end B of the piezoelectric composite vibration layer 20 from being restricted. The sound leakage preventing position limiting member 30 is made of paraxylene, polyimide, SiN or SiO2And polysilicon. The free end B is located between the substrate 10 and the sound leakage preventing stopper 30, and has an overlapping region with the sound leakage preventing stopper 30 in the vertical direction. The sound leakage preventing stopper 30 surrounds the free end B of the piezoelectric composite vibration layer 20, or the sound leakage preventing stopper 30 covers only a part of the free end B of the piezoelectric composite vibration layer 20. The sound leakage preventing stopper 30 includes a first portion contacting the substrate 10 and a second portion connected to the first portion and blocking the self-vibration of the piezoelectric composite vibration layer 20Deflected by end B.
As shown in fig. 3, the present application provides one possible embodiment with respect to the arrangement of the electrode layers. For example, in the embodiment where the piezoelectric composite vibration layer 20 only has the first electrode layer 22 and the second electrode layer 24, the first electrode layer 22 and the second electrode layer 24 respectively have a plurality of partitions isolated from each other, the first electrode layer 22 and the second electrode layer 24 of the same partition form an electrode layer pair, and the electrode layer pairs between different partitions are sequentially connected in series to lead out the voltage generated by the MEMS structure through a lead.
In the embodiment where the piezoelectric composite vibration layer 20 has the first electrode layer 22, the second electrode layer 24, and the third electrode layer, the first electrode layer 22, the second electrode layer 24, and the third electrode layer have at least two partitions isolated from each other, the material of the first electrode layer 22 and the material of the third electrode layer in the same partition are electrically connected and then form an electrode layer pair with the material of the second electrode layer 24 (i.e., the electrode layer pairs in the same partition are connected in parallel), and the electrode layer pairs between different partitions are sequentially connected in series; or the material of the first electrode layer 22 and the material of the second electrode layer 24 in the same partition form a first electrode layer pair, the material of the second electrode layer 24 and the material of the third electrode layer form a second electrode layer pair (i.e. the electrode layer pairs in the same partition are connected in series), the first electrode layer pair and the second electrode layer pair are connected in series to form an electrode layer string, and the electrode layer strings in different partitions are connected in series in sequence.
Based on the MEMS structure provided by the application, the limitation of the piezoelectric composite vibration layer 20 can be realized, the probability that the vibration beam is bent greatly and broken is reduced, and the reliability of the MEMS structure is improved. On the other hand, the sound leakage prevention limiting member 30 increases the sound resistance and reduces the low-frequency sound leakage.
The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (11)
1. A MEMS structure, comprising:
a substrate having a cavity;
the piezoelectric composite vibration layer comprises a fixed end and a free end, the fixed end is connected to the position above the substrate material on the first side of the cavity, the free end is hung above the substrate material on the second side of the cavity, the piezoelectric composite vibration layer covers the cavity, and the first side and the second side of the cavity are oppositely arranged;
a sound-leakage-prevention stopper located above the free end and blocking deflection of the free end of the piezoelectric composite vibration layer.
2. The MEMS structure of claim 1, wherein the piezoelectric composite vibration layer comprises:
a first electrode layer formed over the substrate;
a first piezoelectric layer formed over the first electrode layer;
a second electrode layer formed over the first piezoelectric layer.
3. The MEMS structure of claim 2, wherein the piezoelectric composite vibration layer further comprises:
a vibration support layer formed between the substrate and the first electrode layer.
4. The MEMS structure of claim 2, wherein the piezoelectric composite vibration layer further comprises:
a second piezoelectric layer formed over the second electrode layer;
a third electrode layer formed over the second piezoelectric layer.
5. The MEMS structure of claim 1, wherein the thickness of the substrate material on the first side of the cavity is equal to the thickness of the substrate material on the second side of the cavity, the MEMS structure further comprising a connecting support layer over the substrate, the fixed end being connected to the substrate through the connecting support layer.
6. The MEMS structure of claim 1, wherein the thickness of the substrate material on the first side of the cavity is greater than the thickness of the substrate material on the second side of the cavity, the fixed end is directly connected to and above the substrate material on the first side of the cavity, and the free end is suspended above the substrate material on the second side of the cavity.
7. The MEMS structure of claim 1, wherein the free end is located between the substrate and the sound leakage prevention stop and has an overlapping region in a vertical direction.
8. The MEMS structure of claim 1, wherein the sound leakage prevention stop surrounds the free end of the piezoelectric composite vibration layer; or the sound leakage prevention limiting piece only covers a part of the free end of the piezoelectric composite vibration layer.
9. The MEMS structure of claim 2, wherein the first electrode layer and the second electrode layer respectively have a plurality of partitions isolated from each other, a material of the first electrode layer and a material of the second electrode layer of a same partition constitute an electrode layer pair, and the electrode layer pairs between different partitions are sequentially connected in series.
10. The MEMS structure of claim 4, wherein the first electrode layer, the second electrode layer and the third electrode layer have at least two mutually isolated partitions, the material of the first electrode layer and the material of the third electrode layer in the same partition are electrically connected and then form an electrode layer pair with the material of the second electrode layer, and the electrode layer pairs between different partitions are sequentially connected in series.
11. The MEMS structure of claim 4, wherein the first electrode layer, the second electrode layer and the third electrode layer have at least two isolated partitions, the material of the first electrode layer and the material of the second electrode layer in the same partition form a first electrode layer pair, the material of the second electrode layer and the material of the third electrode layer form a second electrode layer pair, the first electrode layer pair and the second electrode layer pair are connected in series to form an electrode layer string, and the electrode layer strings between different partitions are connected in series in sequence.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921698665.9U CN210183543U (en) | 2019-10-11 | 2019-10-11 | MEMS structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921698665.9U CN210183543U (en) | 2019-10-11 | 2019-10-11 | MEMS structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210183543U true CN210183543U (en) | 2020-03-24 |
Family
ID=69843410
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921698665.9U Active CN210183543U (en) | 2019-10-11 | 2019-10-11 | MEMS structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210183543U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110519679A (en) * | 2019-10-11 | 2019-11-29 | 安徽奥飞声学科技有限公司 | A kind of MEMS structure |
-
2019
- 2019-10-11 CN CN201921698665.9U patent/CN210183543U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110519679A (en) * | 2019-10-11 | 2019-11-29 | 安徽奥飞声学科技有限公司 | A kind of MEMS structure |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10583462B2 (en) | Electromechanical transducer and method of producing the same | |
| US11679461B2 (en) | Support structure and method of forming a support structure | |
| CN210120666U (en) | Piezoelectric MEMS transducer and electronic device | |
| CN102728534B (en) | Electromechanical transducer and manufacture method thereof | |
| CN110099344B (en) | MEMS structure | |
| US11800294B2 (en) | MEMS transducer with improved performance | |
| CN110149582B (en) | Preparation method of MEMS structure | |
| CN110798788B (en) | MEMS structure and forming method thereof | |
| US11750980B2 (en) | MEMS device with enhanced membrane structure and method of forming the same | |
| CN210183543U (en) | MEMS structure | |
| CN110113702B (en) | Manufacturing method of MEMS structure | |
| CN110636421A (en) | MEMS structure and manufacturing method thereof | |
| CN110519679A (en) | A kind of MEMS structure | |
| US20130020910A1 (en) | Vibration power generation device and method of making the same | |
| CN113301484A (en) | MEMS structure and manufacturing method thereof | |
| CN212324361U (en) | MEMS structure | |
| WO2022048382A1 (en) | Mems structure | |
| CN114014254A (en) | MEMS structure | |
| CN111866684A (en) | MEMS structure | |
| CN110677795A (en) | MEMS structure | |
| CN214960116U (en) | MEMS structure | |
| CN111405442A (en) | MEMS structure | |
| CN111246356A (en) | MEMS structure and forming method thereof | |
| CN214799877U (en) | MEMS structure | |
| CN210609696U (en) | MEMS structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |