TWI784580B - Piezoelectric mems accelerometer and method for manufacturing the same - Google Patents

Abstract

A piezoelectric MEMS accelerometer includes a carrier, a first electrode layer, a piezoelectric layer and a second electrode layer. The carrier includes a first surface and a second surface opposite to the first surface. The first surface incudes a first protruding portion and a second protruding portion. The first protruding portion protrudes from the first surface. The second protruding portion protrudes from the first surface and is spaced apart from the first protruding portion. The first electrode layer is disposed on the second surface, the piezoelectric layer is disposed on the first electrode layer, and the second electrode layer is disposed on the piezoelectric layer. A distribution area of the first electrode layer and a distribution area of the second electrode layer are both located within a distribution area of the piezoelectric layer. The first protruding portion is the main component of a proof mass of the piezoelectric MEMS accelerometer, and the second protruding portion is the main component of a connecting portion of the piezoelectric MEMS accelerometer.

Description

Piezoelectric MEMS accelerometer and manufacturing method thereof

The present invention relates to an accelerometer and its manufacturing method, and in particular to a piezoelectric micro-electromechanical accelerometer and its manufacturing method.

An accelerometer is an inertial sensor that obtains the degree of force on an object by measuring acceleration. With the development of micro-electro-mechanical systems (MEMS) manufacturing processes, the size of accelerometers can be greatly reduced and mass-manufactured, and are widely used in various fields.

However, when using the MEMS process to manufacture accelerometers, it needs to go through multiple photolithography processes. During exposure and development, it is easy to cause short-circuit damage to accelerometers due to factors such as exposure machine alignment errors and mask pattern errors, reducing the production quality. Rate.

The object of the present invention is to provide a piezoelectric MEMS accelerometer and its manufacturing method to solve the above problems.

According to one embodiment of the present invention, a piezoelectric MEMS accelerometer is provided, comprising a Carrier, a first electrode layer, a piezoelectric layer and a second electrode layer. The carrier includes a first surface and a second surface opposite to the first surface. The first surface includes a first protrusion and a second protrusion, the first protrusion protrudes from the first surface, and the second protrusion protrudes from the first surface and is spaced apart from the first protrusion. The first electrode layer is arranged on the second surface, the piezoelectric layer is arranged on the first electrode layer, and the second electrode layer is arranged on the piezoelectric layer. The distribution ranges of the first electrode layer and the second electrode layer are both within the distribution range of the piezoelectric layer. The first protruding part is the main component of the mass block of the piezoelectric microelectromechanical accelerometer, and the second protruding part is the main component of the connection part of the piezoelectric microelectromechanical accelerometer.

Another embodiment of the present invention provides a method for manufacturing a piezoelectric MEMS accelerometer, which includes the following steps. A substrate is provided, and the substrate includes a top surface and a bottom surface opposite to the top surface. A first electrode layer is formed so that the first electrode layer is located on the top surface and partially covers the top surface. A piezoelectric layer is formed such that the piezoelectric layer is located on the first electrode layer. A second electrode layer is formed so that the second electrode layer is located on the piezoelectric layer. An etching step is performed to remove a portion of the substrate so that the substrate forms a carrier, wherein the carrier includes a first surface and a second surface opposite to the first surface, the first surface includes a first bump portion and a first surface Two protrusions, the first protrusion protrudes from the first surface, the second protrusion protrudes from the first surface and is spaced apart from the first protrusion, the first surface, the first protrusion and the second protrusion The part is formed by inward depression after the bottom surface is etched, and the second surface is the remaining part after the top surface is etched. In the piezoelectric MEMS accelerometer, both the first electrode layer and the second electrode layer are located within the distribution range of the piezoelectric layer. The first protruding part is the main component of the mass block of the piezoelectric microelectromechanical accelerometer, and the second protruding part is the main component of the connection part of the piezoelectric microelectromechanical accelerometer.

Compared with the prior art, the piezoelectric MEMS accelerometer of the present invention can effectively separate the first electrode layer and the second electrode layer through the piezoelectric layer because the first electrode layer and the second electrode layer are located within the distribution range of the piezoelectric layer. The electrode layer can reduce the short circuit of the first electrode layer and the second electrode layer, which is conducive to improving the Yield of piezoelectric MEMS accelerometers.

100: Piezoelectric MEMS Acceleration Gauge

110: carrier

110a: Ontology

110b: insulating layer

111: first surface

112: the first protrusion

113: the second protrusion

115: second surface

116: The first area

117: Second area

130: the first electrode layer

140: electrode adhesive layer

150: piezoelectric layer

170: second electrode layer

190: etching protective layer

210: Substrate

211: Bottom

215: top surface

221,222,223: Groove

300: photoresist layer

900: Manufacturing method of piezoelectric MEMS accelerometer

910~980: steps

A: Connecting part

B: cantilever beam

C: mass block

P: part

D1: Portrait direction

D2: Horizontal direction

E1, E2, L1, L2: Length

H1, H2: Height

X1: first length

X2: second length

X3: Distance

W1, W2: width

X, Y, Z: coordinate axes

FIG. 1 is a schematic perspective view of the appearance of a piezoelectric MEMS accelerometer according to an embodiment of the present invention.

Fig. 2 is a schematic top view of the piezoelectric MEMS accelerometer in Fig. 1.

Fig. 3 is a schematic side view of the piezoelectric MEMS accelerometer in Fig. 1.

Figure 4 is a schematic cross-sectional view of the piezoelectric MEMS accelerometer in Figure 1 .

Fig. 5 is a schematic partial top view of the piezoelectric MEMS accelerometer in Fig. 4.

Figures 6 to 8 are schematic diagrams of the manufacturing process of the piezoelectric MEMS accelerometer in Figure 4 .

FIG. 9 is a flow chart of the steps of the manufacturing method of the piezoelectric MEMS accelerometer according to another embodiment of the present invention.

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of preferred embodiments with reference to the drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front, back, top, bottom, etc., are only directions referring to the attached drawings. Accordingly, the directional terms used are illustrative rather than limiting of the invention. The dimensions of the components in the drawings are only indicative of relative positions or configurations, and do not limit the dimensions of the components of the present invention. In each of the following embodiments, the same or similar components will use the same or similar symbols.

In the present invention, an element is arranged/located on another element, may mean that said element is directly arranged/located on said another element, there is no other element between them, and it may also mean that said element is indirectly Disposed/located above said another element, with other elements interposed therebetween.

In the following, for the convenience of explaining the directions of each element, the description is made in conjunction with the XYZ rectangular coordinate system.

Hereinafter, for the sake of brevity, the first electrode layer, the piezoelectric layer, the second electrode layer, the electrode adhesion layer, the etching protection layer, the insulating layer and other film layers may be referred to as "film layers" for short, and "film layers" actually represent The meaning of "coordinates" with upper, lower and schema.

<Piezoelectric MEMS accelerometer>

Please refer to Figures 1 to 3, Figure 1 is a schematic perspective view of the appearance of a piezoelectric MEMS accelerometer 100 according to an embodiment of the present invention, and Figure 2 is a top view of the piezoelectric MEMS accelerometer 100 in Figure 1 Schematic diagram, Fig. 3 is a schematic side view of the piezoelectric MEMS accelerometer 100 in Fig. 1 . The piezoelectric MEMS accelerometer 100 includes a connection part A, a cantilever beam (Cantilever beam) B and a mass block (Proof mass) C, and the cantilever beam B is connected between the connection part A and the mass block C, wherein the mass block C is subjected to external force to generate motion, which can transfer energy to the cantilever beam B, and through the piezoelectric layer on the cantilever beam B (refer to the piezoelectric layer 150 in Figure 4), the energy can be converted into electrical signals, and the connecting part A It is used to connect the piezoelectric microelectromechanical accelerometer 100 to an object, for example, the object can be a circuit board, so that the piezoelectric microelectromechanical accelerometer 100 can be integrated into the electronic circuit, and the aforementioned electrical signal can be transmitted to In the electronic circuit, it is converted into acceleration. In other words, the piezoelectric MEMS accelerometer 100 is exemplified here as a cantilever beam accelerometer, however, the present invention is not limited thereto. In other implementations, the piezoelectric MEMS accelerometer 100 can be a high-bandwidth disk-type accelerometer. gauge or triaxial accelerometer.

Please refer to FIG. 4 , which is a schematic cross-sectional view of the piezoelectric MEMS accelerometer 100 in FIG. 1 . The piezoelectric MEMS accelerometer 100 includes a carrier 110 , a first electrode layer 130 , a piezoelectric layer 150 and a second electrode layer 170 , and optionally includes a second electrode adhesive layer 140 and an etching protection layer 190 .

The carrier 110 includes a first surface 111 and a second surface 115 , and the second surface 115 is opposite to the first surface 111 . The first surface 111 includes a first protrusion portion 112 and a second protrusion portion 113, the first protrusion portion 112 protrudes from the first surface 111, the second protrusion portion 113 protrudes from the first surface 111, and is in contact with the second protrusion portion 113 A protrusion portion 112 is arranged at intervals. The first electrode layer 130 is disposed on the second surface 115 , the piezoelectric layer 150 is disposed on the first electrode layer 130 , and the second electrode layer 170 is disposed on the piezoelectric layer 150 .

The proof mass C includes the first protrusion part 112 and the etching protection layer 190 below it and the piezoelectric layer 150 above it, and the connection part A includes the second protrusion part 113 and the etching protection layer 190 below it and the two electrodes above it. layer 140 , first electrode layer 130 , piezoelectric layer 150 , and second electrode layer 170 . In practice, the thickness of each film layer (about 0.2 μm ~ 1.0 μm) is much lower than the thickness (about 400 μm) of the first bump portion 112 and the second bump portion 113, therefore, the first bump portion 112 is piezoelectric The mass block C of the piezoelectric MEMS accelerometer 100 is the main component, and the second protrusion portion 113 is the main component of the connecting portion A of the piezoelectric MEMS accelerometer 100 . In order to clearly show each film layer in FIG. 4 , the thickness of each film layer is enlarged, that is, the thicknesses of each film layer, the first bump portion 112 and the second bump portion 113 are not drawn according to the actual scale. In addition, since the thickness of each film layer is very thin, the surface height difference caused by each film layer on the piezoelectric MEMS accelerometer 100 is not shown in FIGS. 1 to 3 .

The distribution ranges of the first electrode layer 130 and the second electrode layer 170 are all within the distribution range of the piezoelectric layer 150, and the aforementioned "the distribution ranges of the first electrode layer 130 and the second electrode layer 170 are all within the distribution range of the piezoelectric layer 150." Inner" means that the first electrode layer 130 has a coverage area (not otherwise labeled) on the second surface 115, the second electrode layer 170 has a coverage area (not otherwise labeled) on the second surface 115, and the piezoelectric layer 150 There is a coverage area (not otherwise labeled) on the second surface 115, and the coverage areas of the first electrode layer 130 and the second electrode layer 170 on the second surface 115 are smaller than the coverage area of the piezoelectric layer 150 on the second surface 115 , and both Within the coverage area of the piezoelectric layer 150 on the second surface 115, as shown in FIG. The length E2 of the layer 150 on the X axis is greater than the length E1 of the first electrode layer 130 and the second electrode layer 170 . Thereby, the piezoelectric layer 150 can effectively separate the first electrode layer 130 and the second electrode layer 170, which can reduce the occurrence of short circuit between the first electrode layer 130 and the second electrode layer 170, and is beneficial to improve the piezoelectric MEMS accelerometer. 100% yield.

W1/W2

2。第3圖中，懸臂樑B具有一高度H1，質量塊C具有一高度H2，高度H1、H2皆平行於Z軸，其可滿足下列條件：1/40

H1/H2

3/20。藉此尺寸配置，有利於提升壓電式微機電加速規100的靈敏度。 In Fig. 2 , the cantilever beam B has a length L1, and the proof mass C has a length L2. The lengths L1 and L2 are both parallel to the X-axis, which can satisfy the following condition: L1/L2=5. The cantilever beam B has a width W1, the proof mass C has a width W2, and the lengths W1 and W2 are both parallel to the Y axis, which can satisfy the following conditions: 1/3

W1/W2

2. In Figure 3, the cantilever beam B has a height H1, and the mass block C has a height H2. The heights H1 and H2 are both parallel to the Z-axis, which can satisfy the following conditions: 1/40

H1/H2

3/20. This size configuration is beneficial to improve the sensitivity of the piezoelectric MEMS accelerometer 100 .

Please refer to FIG. 4 and FIG. 5 at the same time. FIG. 5 is a partial top view of the piezoelectric MEMS accelerometer 100 in FIG. 4 . In order to show the relationship between the first electrode layer 130 and the piezoelectric layer 150 in Fig. 5, the electrode adhesive layer 140 and the second electrode layer 170 are omitted, and the first electrode layer 130 is represented by dots, and the piezoelectric layer 150 is represented by dots. indicated by a slash. The second surface 115 includes a first region 116 and a second region 117, the second region 117 is connected to the first region 116, the first region 116 corresponds to the first bump portion 112, and the first electrode layer 130 is disposed in the second region 117 on. The piezoelectric layer 150 is disposed on the first electrode layer 130 and completely covers the second region 117 . Meanwhile, the piezoelectric layer 150 extends to the first region 116 and completely covers the first region 116 . In this way, the piezoelectric layer 150 disposed above the first region 116 can be used as a protective layer for the carrier 110 in the process of manufacturing the piezoelectric MEMS accelerometer 100, which is beneficial to reduce one sputtering step and one lithography step, Therefore, the process efficiency can be improved and the cost can be reduced. In addition, the second region 117 has a longitudinal direction D1 parallel to the X axis, the second region 117 has a transverse direction D2 parallel to the Y axis, the longitudinal direction D1 and the transverse direction D2 are perpendicular to each other, the first The distribution range of the electrode layer 130 has a first length X1 along the lateral direction D2, the distribution range of the piezoelectric layer 150 has a second length X2 along the lateral direction D2, the second length X2 is parallel to the first length X1, and the second The length X2 is greater than the first length X1, preferably, the first length X1 is 85% to 95% of the second length X2, thereby facilitating the contact between the edge of the piezoelectric layer 150 and the edge of the first electrode layer 130 Reserving a sufficient distance X3 is beneficial to improve the effect of separating the first electrode layer 130 and the second electrode layer 170 by the piezoelectric layer 150 .

In detail, the carrier 110 may include a main body 110a and two insulating layers 110b respectively disposed on the upper and lower surfaces of the main body 110a. The body 110a can be a silicon wafer, or other materials with high resistance, high temperature resistance and etching resistance, for example, the resistivity is greater than or equal to 0.5Ωcm, can withstand high temperatures above 600°C, and can resist acetone, isopropanol and developer corroded material. The insulating layer 110b can be silicon dioxide, or other insulating materials that can reduce the influence of wire leakage current, such as silicon nitride (Si ₃ N ₄ ) or oxynitride dopant. When the insulating ability of the body 110a itself is good enough to reduce the influence of the wire leakage current, the insulating layer 110b can be omitted.

The material of the first electrode layer 130 and the second electrode layer 170 can be platinum, or other materials suitable as electrodes and having electrical conductivity, such as silver, aluminum, gold, titanium nitride (TiN), nickel, copper, tin, etc. .

The electrode adhesive layer 140 can be disposed between the second surface 115 and the first electrode layer 130. The electrode adhesive layer 140 is used to enhance the adhesion between the first electrode layer 130 and the second surface 115. Therefore, when an electrode layer When the materials of the 130 and the carrier 110 can provide sufficient adhesion to each other, the electrode adhesive layer 140 can be omitted between the first electrode layer 130 and the second surface 115 . Similarly, the electrode adhesive layer 140 is used to enhance the adhesion between the second electrode layer 170 and the piezoelectric layer 150. When the materials of the second electrode layer 170 and the piezoelectric layer 150 can provide sufficient adhesion to each other, the second The electrode adhesive layer 140 can be omitted between the two electrode layers 170 and the piezoelectric layer 150 . The electrode adhesive layer 140 can be made of titanium, zinc oxide, aluminum nitride, aluminum oxide, titanium nitride, or titanium dioxide.

The material of the piezoelectric layer 150 can be a piezoelectric material, preferably, the material of the piezoelectric layer 150 can be Li:ZnO, wherein the ratio of Li is 1 mole percent to 10 mole percent, whereby the piezoelectric layer 150 The ingredients are lead-free to avoid environmental pollution.

The etch protection layer 190 is disposed on the side of the first protrusion portion 112 away from the first surface 111, and is disposed on the side of the second protrusion portion 113 away from the first surface 111. The etch protection layer 190 is used for the etching step , to protect the first bump portion 112 and the second bump portion 113 from being etched, the material of the etching protection layer 190 can be metal or inorganic, such as zinc oxide, aluminum nitride, aluminum oxide, silver, aluminum, gold, nitrogen Titanium, nickel, copper, tin, etc. In other embodiments, after the etching step, the etching protection layer 190 can be removed, so the etching protection layer 190 is a selective film layer.

<Manufacturing method of piezoelectric MEMS accelerometer>

Please refer to FIG. 9 , which is a flowchart of steps of a method 900 for manufacturing a piezoelectric MEMS accelerometer according to another embodiment of the present invention. The method 900 for manufacturing a piezoelectric MEMS accelerometer includes steps 910 to 980, wherein steps 920 and 950 are optional steps. Please refer to Figures 6 to 8 at the same time, which are schematic diagrams of the manufacturing process of the piezoelectric MEMS accelerometer 100 in Figure 4. Here, Figures 6 to 8 illustrate the manufacturing method of the piezoelectric MEMS accelerometer 900.

Step 910 is to provide a substrate. As shown in the sub-figure of FIG. 6( a ), the substrate 210 includes a top surface 215 and a bottom surface 211 . Relative to the top surface 215 , the substrate 210 may include a body 110 a and two insulating layers 110 b.

Step 920 is to form an electrode adhesive layer. Step 930 is to form a first electrode layer. As shown in the sub-figure of FIG. 6 (b), in order to define the patterns of the electrode adhesive layer 140 and the first electrode layer 130, a patterned photoresist layer 300 is formed on the top surface 215 first, and then the electrode adhesive layer 140 and the first electrode layer 130 are sequentially formed. The first electrode layer 130 . Later profit The photoresist layer 300 and the film layer above it are removed by a lift-off process. As a result, as shown in the sub-figure of FIG. 6 (c), the electrode adhesive layer 140 and the first electrode layer 130 are located on the top surface 215 and The top surface 215 is partially covered.

Step 940 is to form a piezoelectric layer. As shown in the sub-figure of FIG. 6 (d), the piezoelectric layer 150 and the patterned photoresist layer 300 are sequentially formed, and then the photoresist layer 300 and part of the piezoelectric layer 150 are removed by a wet etching process. The result is shown in the sub-figure (a) of FIG. 7 , wherein the piezoelectric layer 150 is located on the first electrode layer 130 , and the first electrode layer 130 is located within the distribution range of the piezoelectric layer 150 .

Step 950 is to form an electrode adhesive layer. Step 960 is to form a second electrode layer. As shown in the sub-figure of Figure 7 (b), in order to define the pattern of the electrode adhesive layer 140 and the second electrode layer 170, a patterned photoresist layer 300 is formed first, and then the electrode adhesive layer 140 and the second electrode layer are formed in sequence. 170. Afterwards, the photoresist layer 300 and the film layer above it are removed by lift-off process. As a result, as shown in the sub-figure of FIG. 7 (c), the electrode adhesive layer 140 and the second electrode layer 170 are located on the piezoelectric layer 150, and the second The electrode layer 170 is located within the distribution range of the piezoelectric layer 150 .

Step 970 is to form an etch stop layer. As shown in the sub-figure of Figure 7 (d), in order to define the pattern of the etching stopper layer 190, a patterned photoresist layer 300 is first formed, and then the etching stopper layer 190 is formed, and then the photoresist layer 300 and the adhesion are removed by a lift-off process. The result of the etching stopper layer 190 on it is as shown in the sub-figure of FIG. 8( a ), so as to obtain a patterned etching stopper layer 190 . The etch stopper layer 190 is located on the bottom surface 211 .

Step 980 is to perform an etching step to remove a part of the substrate 210 so that the substrate 210 forms the carrier 110 . As shown in the sub-figure of FIG. 8( b ), part of the upper insulating layer 110 b is removed to form the groove 221 . And part of the insulating layer 110b located below is removed to form the grooves 222 and 223 . Continue to etch away part of the main body 110a at the groove 221 to make the groove 221 deeper, and the result is shown in the sub-figure of FIG. 8 (c). then by the groove 222 and 223 etch away part of the body 110a to cut off the redundant part P and deepen the groove 223, the result is shown in the sub-figure of Figure 8 (d). The substrate 210 becomes the carrier 110 after being etched, the first surface 111 of the carrier 110, the first protruding portion 112 and the second protruding portion 113 are formed by inward depression after the bottom surface 211 is etched, and the second surface 115 is the top surface 215 The remaining part after etching. The etching step may be dry etching, for example, reactive ion etching (Reactive-Ion Etching, RIE) may be performed using an Inductive Couple Plasma Etcher (ICP Etcher).

In the foregoing steps, each film layer can be deposited using a radio frequency magnetron sputtering system. The patterned photoresist layer 300 can be formed by lithography process, and the photoresist layer 300 can be a commercially available product, such as AZ1500. The etching solution used in the wet etching can be an aluminum etching solution, and the soaking solution used in the lift-off process can be acetone. However, the present invention is not limited thereto, and each film layer can be formed by other processes. The details of each film layer can be referred to above, and will not be repeated here.

<Measurement of Properties of Piezoelectric MEMS Accelerometer>

Embodiment 1: According to the manufacturing method 900 of the aforementioned piezoelectric MEMS accelerometer, the piezoelectric MEMS accelerometer in Example 1 is obtained, and the piezoelectric MEMS accelerometer in Example 1 is a cantilever beam accelerometer. Its size and the composition of each film layer are shown in Table 1 and Table 2. For the definition of length L1, L2, height H1, H2 and width W1, W2, please refer to Figure 2 and Figure 3.

The sensitivity test and resonance frequency test of the piezoelectric MEMS accelerometer in Example 1 is performed by using an oscillation system (THE MPDAL SHOP 9100D) to provide a vibration source, so that the piezoelectric MEMS accelerometer in Example 1 generates a signal, and through Software (m+p accelerometer measuring software) analyzes the signal, and the sensitivity of the piezoelectric MEMS accelerometer in Example 1 is 2mV/g~8mV/g, and the resonance frequency is 200Hz~1000Hz, where mV is millivolts, g is the acceleration of gravity, 1g=9.8m/s ² , which shows that the piezoelectric MEMS accelerometer according to the present invention has excellent sensitivity and resonance frequency.

Compared with the prior art, the piezoelectric MEMS accelerometer of the present invention can effectively separate the first electrode layer and the second electrode layer through the piezoelectric layer because the first electrode layer and the second electrode layer are located within the distribution range of the piezoelectric layer. The electrode layer can reduce the short circuit between the first electrode layer and the second electrode layer, and is beneficial to improve the yield rate of the piezoelectric MEMS accelerometer. Preferably, by extending the piezoelectric layer to the first region and completely covering the first region, when manufacturing a piezoelectric MEMS accelerometer, it is beneficial to reduce one sputtering step and one lithography step, thereby improving process efficiency and reducing cost.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

100: Piezoelectric MEMS Acceleration Gauge

110: carrier

110a: Ontology

110b: insulating layer

111: first surface

112: the first protrusion

113: the second protrusion

115: second surface

116: The first area

117: Second area

130: the first electrode layer

140: electrode adhesive layer

150: piezoelectric layer

170: second electrode layer

190: etching protective layer

A: Connecting part

B: cantilever beam

C: mass block

E1, E2: Length

X, Z: coordinate axis

Claims (11)

A piezoelectric micro-electromechanical accelerometer, comprising: a carrier, including: a first surface, including: a first protruding part, protruding from the first surface; and a second protruding part, protruding from the first surface , and spaced apart from the first bump portion; and a second surface, opposite to the first surface; a first electrode layer, arranged on the second surface; a piezoelectric layer, arranged on the first electrode layer; and a second electrode layer disposed on the piezoelectric layer; wherein the distribution ranges of the first electrode layer and the second electrode layer are both within the distribution range of the piezoelectric layer; wherein the first bump The part is the main component of a mass block of the piezoelectric micro-electromechanical accelerometer, and the second protruding part is the main component of a connection part of the piezoelectric micro-electromechanical accelerometer. The piezoelectric MEMS accelerometer as claimed in claim 1, wherein the second surface includes a first region and a second region connected to the first region, the first region corresponds to the first protrusion, and the first region An electrode layer is disposed on the second region. The piezoelectric MEMS accelerometer according to claim 2, wherein the piezoelectric layer extends to the first region and completely covers the first region and the second region. The piezoelectric MEMS accelerometer as described in Claim 1 further includes: At least one electrode adhesive layer is disposed between the second surface and the first electrode layer and/or between the piezoelectric layer and the second electrode layer. The piezoelectric MEMS accelerometer as claimed in claim 1 further includes: an etching protection layer disposed on a side of the first protrusion part away from the first surface. The piezoelectric MEMS accelerometer as claimed in claim 1, wherein the distribution range of the first electrode layer has a first length, the distribution range of the piezoelectric layer has a second length parallel to the first length, and the first The length is 85% to 95% of the second length. A method for manufacturing a piezoelectric MEMS accelerometer, comprising: providing a substrate, the substrate including a top surface and a bottom surface opposite to the top surface; forming a first electrode layer so that the first electrode layer is located on the top surface and partially cover the top surface; forming a piezoelectric layer, such that the piezoelectric layer is located on the first electrode layer; forming a second electrode layer, such that the second electrode layer is located on the piezoelectric layer; and performing an etching step, removing a part of the substrate, so that the substrate forms a carrier, wherein the carrier includes a first surface and a second surface opposite to the first surface, the first surface includes a first bump portion and A second protruding part, the first protruding protruding from the first surface, the second protruding protruding from the first surface and spaced apart from the first protruding part, the first surface, the first protruding A protruding part and the second protruding part are formed by inward depression after the bottom surface is etched, and the second surface is the remaining part after the top surface is etched; wherein in the piezoelectric MEMS accelerometer, Both the first electrode layer and the second electrode layer are located within the distribution range of the piezoelectric layer; wherein the first protruding part is the main component of a mass block of the piezoelectric MEMS accelerometer, the The second protruding part is the main component of a connecting part of the piezoelectric MEMS accelerometer. The manufacturing method of the piezoelectric MEMS accelerometer according to claim 7, wherein the second surface includes a first region and a second region connected to the first region, and the first region corresponds to the first protrusion , forming the piezoelectric layer further includes making the piezoelectric layer cover the portion of the top surface not covered by the first electrode layer, so that in the piezoelectric MEMS accelerometer, the first electrode layer is disposed on the second area, wherein the piezoelectric layer extends to the first area and completely covers the first area and the second area. The manufacturing method of the piezoelectric MEMS accelerometer according to claim 7, wherein before forming the first electrode layer, it further includes: forming an electrode adhesive layer, so that the electrode adhesive layer is located on the top surface and partially covers the top surface noodle. The manufacturing method of the piezoelectric MEMS accelerometer according to claim 7, further includes: forming an electrode adhesive layer, so that the electrode adhesive layer is located on the piezoelectric layer before forming the second electrode layer. The manufacturing method of the piezoelectric micro-electromechanical accelerometer according to claim 7, further comprising: forming an etching barrier layer so that the etching barrier layer is located on the bottom surface before performing the etching step.

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