WO2022188521A1

WO2022188521A1 - Air pressure sensor chip and method for preparing same

Info

Publication number: WO2022188521A1
Application number: PCT/CN2021/143029
Authority: WO
Inventors: 李向光; 田峻瑜; 方华斌
Original assignee: 潍坊歌尔微电子有限公司
Priority date: 2021-03-10
Filing date: 2021-12-30
Publication date: 2022-09-15
Also published as: CN113125069A

Abstract

An air pressure sensor chip and a method for preparing same. The air pressure sensor chip comprises two first capacitors (101) and two second capacitors (102), wherein one of the two first capacitors (101) is connected in series with one of the two second capacitors (102) to form a first branch, the other one of the two first capacitors (101) is connected in series with the other one of the two second capacitors (102) to form a second branch, and the first branch is connected in parallel with the second branch; the first capacitors (101) are configured such that the capacitance values thereof increase under the action of external air pressure; and the second capacitors (102) are configured such that the capacitance values thereof decrease under the action of external air pressure.

Description

Air pressure sensor chip and preparation method thereof

This disclosure claims the priority of the Chinese patent application with the application number 202110259166.5 and the application title "Air Pressure Sensor Chip and Method for Making the Same", which was filed with the China Patent Office on March 10, 2021, the entire contents of which are incorporated in this disclosure by reference .

technical field

The present disclosure relates to the technical field of electronic products, and more particularly, to an air pressure sensor chip and a preparation method thereof.

Background technique

With the development of science and technology, all kinds of electronic products have entered thousands of households and become people's daily necessities. Many electronic products have air pressure sensor chips. The air pressure sensor chip is a device used to measure ambient air pressure. Air pressure is a physical quantity closely related to people's daily life. Air pressure data can be used to detect vertical changes in altitude. Sports monitoring, indoor navigation and auxiliary weather forecasting, etc. Therefore, air pressure sensor chips are widely used in smart wear and smart home fields to measure the air pressure information of the location of the product.

In order to ensure the accuracy of the measurement results, the sensitivity of the air pressure sensor chip is particularly important. At present, most of the air pressure sensor chips in the prior art are composed of a single capacitor or two capacitors, and the output sensitivity thereof is low, which is likely to cause a large measurement error.

In view of this, it is necessary to provide a new technical solution to solve the above technical problems.

SUMMARY OF THE INVENTION

An object of the present disclosure is to provide a new technical solution for an air pressure sensor chip and a manufacturing method thereof.

According to a first aspect of the present disclosure, an air pressure sensor chip is provided, and the air pressure sensor chip includes:

two first capacitors and two second capacitors;

One of the two first capacitors and one of the two second capacitors are connected in series to form a first branch, and the other of the two first capacitors is connected to the two second capacitors The other one of them is connected in series to form a second branch, and the first branch is connected in parallel with the second branch;

The first capacitor is configured so that the capacitance value can be increased under the action of external air pressure;

The second capacitor is configured such that the capacitance value can be reduced under the action of external air pressure.

Optionally, the first capacitor includes a first electrode and a second electrode disposed opposite to each other, a first vacuum chamber is formed between the first electrode and the second electrode, and the first electrode and the second electrode It is arranged that: when there is no external air pressure, the first electrode and the second electrode are parallel to each other; when the external air pressure acts, the second electrode can approach the first electrode under the effect of the external air pressure to make the The spacing between the first electrode and the second electrode is reduced.

Optionally, the second capacitor includes a third electrode and a fourth electrode disposed opposite to each other, and a second vacuum cavity is formed on the side of the third electrode away from the fourth electrode of the second capacitor, so The fourth electrode is provided with a ventilating through hole, and the external air pressure can act on the third electrode through the ventilating through hole, and the third electrode and the fourth electrode are arranged so that when there is no external air pressure, all the The third electrode and the fourth electrode are parallel to each other; when the external air pressure acts, the third electrode can be away from the fourth electrode under the action of the external air pressure, so that the third electrode and the fourth electrode can be separated The spacing between them increases.

According to a second aspect of the present disclosure, there is provided a method for fabricating an air pressure sensor chip according to the first aspect, the method comprising:

Prepare a first capacitor, the first capacitor is configured so that the capacitance value can be increased under the action of the external air pressure; two first capacitors are prepared;

preparing a second capacitor, the second capacitor is configured so that the capacitance value can be reduced under the action of the external air pressure; two second capacitors are prepared;

A first branch is formed by connecting one of the two first capacitors in series with one of the two second capacitors;

connecting the other of the two first capacitors in series with the other of the two second capacitors to form a second branch;

The first branch is connected in parallel with the second branch.

Optionally, the preparing the first capacitor includes:

providing a first substrate, and performing ion implantation doping on the first substrate to form a first electrode;

depositing a first support layer on the first substrate;

depositing a semiconductor layer on the first support layer to form a second electrode; and,

The first support layer is partially etched to expose the first electrode relative to the second electrode while forming a first vacuum cavity between the first electrode and the second electrode.

Optionally, the local etching of the first support layer includes:

A first etching hole is formed by etching on the semiconductor layer, and the first etching hole is connected to the first support layer;

etching and removing a part of the first support layer through the first etching hole, so that the first electrode is exposed relative to the second electrode;

A first sealing layer is deposited on the semiconductor layer, the first sealing layer sealing the first etch hole.

Optionally, after depositing the first sealing layer on the semiconductor layer, the method further includes:

A first protective layer is deposited on the first sealing layer.

Optionally, the preparing the second capacitor includes:

providing a second substrate on which a second support layer is deposited;

depositing a semiconductor layer on the second support layer to form a third electrode;

partially etching the second support layer to expose a portion of the third electrode relative to the second substrate while forming a second vacuum cavity between the third electrode and the second substrate;

depositing a third support layer on the third electrode;

depositing a semiconductor layer on the third support layer to form a fourth electrode;

Etching to form air-permeable through holes on the fourth electrode;

A part of the third support layer is removed by etching through the air-permeable through hole, so that the air-permeable through hole is exposed relative to the third electrode.

Optionally, the partially etching the second support layer includes:

A second etching hole is formed by etching on the third electrode, and the second etching hole is connected to the second supporting layer;

etching a part of the second support layer through the second etching hole to expose a part of the third electrode relative to the second substrate;

A second sealing layer is deposited on the third electrode, and the second sealing layer seals the second etching hole.

Optionally, after depositing the second sealing layer on the third electrode, the method further includes:

A second protective layer is deposited on the second sealing layer.

The output sensitivity of the air pressure sensor chip provided by an embodiment of the present disclosure is high, which can effectively suppress interference and make the measurement more accurate.

Other features of the present disclosure and advantages thereof will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

FIG. 1 is a schematic structural diagram of an air pressure sensor chip according to an embodiment of the present disclosure;

2 is a schematic structural diagram of a first capacitor in an air pressure sensor chip according to an embodiment of the present disclosure;

3 is a schematic structural diagram of a second capacitor in an air pressure sensor chip according to an embodiment of the present disclosure;

4-11 are schematic diagrams of a manufacturing process of a first capacitor in an air pressure sensor chip according to an embodiment of the present disclosure;

12 to 21 are schematic diagrams of a manufacturing process of a second capacitor in an air pressure sensor chip according to an embodiment of the present disclosure.

Detailed ways

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application or uses in any way.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

In all examples shown and discussed herein, any specific values should be construed as illustrative only and not limiting. Accordingly, other instances of the exemplary embodiment may have different values.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further discussion in subsequent figures.

Referring to FIG. 1 , according to an embodiment of the present disclosure, an air pressure sensor chip is provided. The air pressure sensor chip includes two first capacitors 101 and two second capacitors 102; one of the two first capacitors 101 and one of the two second capacitors 102 are connected in series to form a first branch circuit, the other of the two first capacitors 101 is connected in series with the other of the two second capacitors 102 to form a second branch, and the first branch is connected in parallel with the second branch ; The first capacitor 101 is configured so that the capacitance value can be increased under the action of the external air pressure; the second capacitor 102 is configured so that the capacitance value can be reduced under the action of the external air pressure. Further, the first branch is connected with a first output terminal (Out_P), and the second branch is connected with a second output terminal (Out_N).

In the air pressure sensor chip provided by the embodiment of the present application, a total of four capacitors are used, namely, two first capacitors 101 and two second capacitors 102 . The capacitance of the first capacitor 101 increases under the action of the external air pressure, while the capacitance of the second capacitor 102 decreases under the action of the outside air pressure. In this way, the output result of the first output terminal (Out_P) integrates the change of the capacitance value of the first capacitor 101 and the change of the capacitance value of the second capacitor 102 . Similarly, the output result of the second output terminal (Out_N) also integrates the change of the capacitance value of the first capacitor 101 . The capacitance value changes and the capacitance value of the second capacitor 102 changes. Therefore, the output sensitivity of the air pressure sensor chip is higher. More specifically, in the air pressure sensor chip, four capacitors form a Wheatstone capacitor full bridge structure. Under the action of alternating excitation, the external air pressure can be converted into the differential output of the capacitor full bridge, which can effectively suppress interference. Measurements are more precise.

Referring to FIG. 2 , in one embodiment, the first capacitor 101 includes a first electrode 1011 and a second electrode 1012 arranged opposite to each other, the second electrode 1012 is arranged facing the outside air pressure, and the first electrode 1011 is located at A first vacuum chamber 1013 is formed between the first electrode 1011 and the second electrode 1012 on the side of the second electrode 1012 away from the outside air pressure. The second electrode 1012 can be under the action of the outside air pressure. Close to the first electrode 1011 to reduce the distance between the first electrode 1011 and the second electrode 1012 .

In this specific example, the first electrode 1011 and the second electrode 1012 arranged opposite to each other form a parallel plate capacitor, that is to say, when there is no external air pressure, the first electrode 1011 and the second electrode 1012 are arranged parallel to each other of. Since the first vacuum chamber 1013 is formed between the first electrode 1011 and the second electrode 1012, when the external air pressure acts on the second electrode 1012, there is a pressure difference between the external air pressure and the first vacuum chamber 1013, and the second electrode 1012 is outside Under the action of the pressure of air pressure, it deforms and approaches the first electrode 1011 , so that the distance d1 between the first electrode 1011 and the second electrode 1012 becomes smaller, thereby causing the capacitance of the first capacitor 101 to increase. It can be understood that when the external air pressure increases, the distance d1 between the first electrode 1011 and the second electrode 1012 becomes smaller and the amplitude increases, thereby causing the capacitance value of the first capacitor 101 to increase in amplitude; and When the outside air pressure decreases, the distance d1 between the first electrode 1011 and the second electrode 1012 becomes smaller and the amplitude decreases, thereby causing the amplitude of the increase in the capacitance value of the first capacitor 101 to decrease.

Referring to FIG. 3 , in one embodiment, the second capacitor 102 includes a third electrode 1021 and a fourth electrode 1022 disposed opposite to each other, the fourth electrode 1022 is disposed facing the outside air pressure, and the third electrode 1021 is located at On the side of the fourth electrode 1022 away from the outside air pressure, the second capacitor 102 is formed with a second vacuum chamber 1023 on the side of the third electrode 1021 away from the fourth electrode 1022 . The electrode 1022 is provided with a ventilation through hole 10221, the external air pressure can act on the third electrode 1021 through the ventilation through hole 10221, and the third electrode 1021 can be away from the fourth electrode 1022 under the action of the external air pressure to The distance between the third electrode 1021 and the fourth electrode 1022 is increased.

In this specific example, the third electrode 1021 and the fourth electrode 1022 arranged opposite to each other form a parallel plate capacitor, that is to say, when there is no external air pressure, the third electrode 1021 and the fourth electrode 1022 are arranged parallel to each other of. Since the second capacitor 102 is formed with a second vacuum chamber 1023 on the side of the third electrode 1021 away from the fourth electrode 1022, and the fourth electrode 1022 is provided with a ventilation through hole 10221, the external air pressure can act through the ventilation through hole 10221 In the third electrode 1021, when the external air pressure acts on the third electrode 1021, there is a pressure difference between the external air pressure and the second vacuum chamber 1023, and the third electrode 1021 is deformed under the pressure of the external air pressure and moves away from the fourth electrode 1022, so that The distance d2 between the third electrode 1021 and the fourth electrode 1022 increases, thereby causing the capacitance value of the second capacitor 102 to decrease. It can be understood that when the external air pressure increases, the distance d2 between the third electrode 1021 and the fourth electrode 1022 becomes larger, thereby causing the decrease in the capacitance value of the second capacitor 102 to become larger; and When the outside air pressure decreases, the magnitude of the increase in the distance d2 between the third electrode 1021 and the fourth electrode 1022 decreases, thereby causing the magnitude of the decrease in the capacitance value of the second capacitor 102 to decrease.

According to another embodiment of the present disclosure, there is also provided a method for fabricating an air pressure sensor chip as described above, the method comprising:

Prepare a first capacitor 101, the first capacitor 101 is configured so that the capacitance value can be increased under the action of the external air pressure; two first capacitors 101 are prepared;

Prepare a second capacitor 102, the second capacitor 102 is configured so that the capacitance value can be reduced under the action of the external air pressure; two second capacitors 102 are prepared;

A first branch is formed by connecting one of the two first capacitors 101 and one of the two second capacitors 102 in series;

Connecting the other of the two first capacitors 101 and the other of the two second capacitors 102 in series to form a second branch;

The first branch is connected in parallel with the second branch.

According to the preparation method provided by the embodiment of the present application, a first capacitor 101 with an increased capacitance value and a second capacitor 102 with a reduced capacitance value are connected in series to form a first branch, and another capacitance value can be increased The first capacitor 101 is connected in series with another second capacitor 102 whose capacitance can be reduced to form a second branch, and then the first branch and the second branch are connected in parallel to form a Wheatstone capacitor full bridge structure. Under the action of , the external air pressure can be converted into the differential output of the capacitive full bridge, which can effectively suppress interference and make the measurement more accurate.

Referring to FIGS. 4-11 , in one embodiment, further, the preparing the first capacitor 101 includes:

S1, providing a first substrate 1014, and performing ion implantation doping on the first substrate 1014 to form a first electrode 1011;

Specifically, an N-type silicon wafer is used as the first substrate 1014; specifically, the ion implantation doping is P-type ion implantation doping.

S2, depositing an insulating layer 1019 on the first electrode 1011;

Specifically, a silicon nitride layer is deposited on the first electrode 1011 as the insulating layer 1019 . More specifically, the thickness of the silicon nitride layer is 0.1um˜0.2um.

S3, depositing a first support layer 1015 on the first substrate 1014;

Specifically, a silicon dioxide layer is deposited on the first substrate 1014 as the first support layer 1015 for supporting the second electrode 1012, and the first support layer 1015 will also be partially etched and removed as a sacrificial layer in subsequent steps; More specifically, the thickness of the silicon dioxide layer is 1 μm˜5 μm.

S4, depositing a semiconductor layer on the first support layer 1015 to form a second electrode 1012;

Specifically, the semiconductor layer is a polysilicon layer; more specifically, the thickness of the polysilicon layer is 1-2um.

S5, etching the semiconductor layer to form a first etching hole 1016, and the first etching hole 1016 is connected to the first support layer 1015;

S6, etch and remove a part of the first support layer 1015 through the first etching hole 1016, so that the first electrode 1011 is exposed relative to the second electrode 1012; A first vacuum chamber 1013 is formed between 1011 and the second electrode 1012;

S7, depositing a first sealing layer 1017 on the semiconductor layer, the first sealing layer 1017 sealing the first etching hole 1016 .

Specifically, a silicon dioxide layer is deposited on the semiconductor layer as the first sealing layer 1017; more specifically, the thickness of the silicon dioxide layer is 1-5um. The silicon dioxide layer is filled into the first etching hole 1016 to seal and block the first etching hole 1016 .

S8 , depositing a first protective layer 1018 on the first sealing layer 1017 .

Specifically, a passivation layer of silicon nitride is deposited on the first sealing layer 1017 as the first protective layer 1018; more specifically, the thickness of the passivation layer of silicon nitride is 1-2 um.

Referring to FIGS. 12-21 , in one embodiment, further, the preparing the second capacitor 102 includes:

P1, providing a second substrate 1024, and depositing a second support layer 1025 on the second substrate 1024;

Specifically, an N-type silicon wafer is used as the second substrate 1024; specifically, a silicon dioxide layer is deposited on the second substrate 1024 as the second support layer 1025 supporting the third electrode 1021, and the second support The layer 1025 will also be partially etched and removed as a sacrificial layer in subsequent steps; more specifically, the thickness of the silicon dioxide layer is 1 μm˜5 μm.

P2, depositing a semiconductor layer on the second supporting layer 1025 to form a third electrode 1021;

P3. A second etching hole 1027 is formed by etching on the third electrode 1021, and the second etching hole 1027 is connected to the second supporting layer 1025;

P4. A part of the second support layer 1025 is etched and removed through the second etching hole 1027, so that a part of the third electrode 1021 is exposed relative to the second substrate 1024. A second vacuum chamber 1023 is formed between the three electrodes 1021 and the second substrate 1024;

P5, depositing a second sealing layer 1028 on the third electrode 1021, the second sealing layer 1028 sealing the second etching hole 1027;

Specifically, a silicon dioxide layer is deposited on the third electrode 1021 as the second sealing layer 1028; more specifically, the thickness of the silicon dioxide layer is 1-5um. The silicon dioxide layer is filled into the second etching hole 1027 to seal and block the second etching hole 1027 .

P6, depositing a second protective layer 1029 on the second sealing layer 1028;

Specifically, a passivation layer of silicon nitride is deposited on the second sealing layer 1028 as the second protective layer 1029; more specifically, the thickness of the passivation layer of silicon nitride is 1-2 um.

P7, depositing a third support layer 1026 on the second protective layer 1029 on the third electrode 1021;

Specifically, a silicon dioxide layer is deposited on the second protective layer 1029 on the third electrode 1021 to serve as the third support layer 1026 for supporting the fourth electrode 1022. In addition, the third support layer 1026 will also serve as a sacrificial layer in subsequent steps. is removed by partial etching; further specifically, the thickness of the silicon dioxide layer is 1um-5um.

P8, depositing a semiconductor layer on the third supporting layer 1026 to form a fourth electrode 1022;

P9, etching the fourth electrode 1022 to form ventilation through holes 10221;

P10. A part of the third support layer 1026 is etched and removed through the air-permeable through hole 10221, so that the air-permeable through hole 10221 is exposed relative to the second protective layer 1029 on the third electrode 1021.

The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Repeat.

While some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art will appreciate that the above examples are provided for illustration only, and are not intended to limit the scope of the present disclosure. Those skilled in the art will appreciate that modifications may be made to the above embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

An air pressure sensor chip, characterized in that the air pressure sensor chip comprises:

two first capacitors (101) and two second capacitors (102);

One of the two first capacitors (101) and one of the two second capacitors (102) are connected in series to form a first branch, and the other of the two first capacitors (101) The first branch is connected in series with the other of the two second capacitors (102) to form a second branch, and the first branch is connected in parallel with the second branch;

The first capacitor (101) is configured such that the capacitance value can be increased under the action of external air pressure;

The second capacitor (102) is configured such that the capacitance value can be reduced under the action of external air pressure.
The air pressure sensor chip according to claim 1, characterized in that, the first capacitor (101) comprises a first electrode (1011) and a second electrode (1012) that are oppositely arranged, and the first electrode (1011) and A first vacuum chamber (1013) is formed between the second electrodes (1012), and the first electrode (1011) and the second electrode (1012) are arranged so that: when there is no external air pressure, the first electrode (1011) and the second electrode (1012) are parallel to each other; when the external air pressure acts, the second electrode (1012) can approach the first electrode (1011) under the action of the external air pressure to make the first electrode (1011) The spacing between (1011) and the second electrode (1012) is reduced.
The air pressure sensor chip according to claim 1 or 2, characterized in that, the second capacitor (102) comprises a third electrode (1021) and a fourth electrode (1022) that are oppositely arranged, and the second capacitor (102) ) a second vacuum chamber (1023) is formed on the side of the third electrode (1021) away from the fourth electrode (1022), and the fourth electrode (1022) is provided with a ventilation through hole (10221), The external air pressure can act on the third electrode (1021) through the ventilating through hole (10221), and the third electrode (1021) and the fourth electrode (1022) are set so as to: when there is no external air pressure acting , the third electrode (1021) and the fourth electrode (1022) are parallel to each other; when the external air pressure acts, the third electrode (1021) can be away from the fourth electrode (1022) under the action of the external air pressure ) to increase the distance between the third electrode (1021) and the fourth electrode (1022).
A method for preparing an air pressure sensor chip according to any one of claims 1-3, wherein the method comprises:

A first capacitor (101) is prepared, and the first capacitor (101) is configured such that the capacitance value can be increased under the action of external air pressure; two first capacitors (101) are prepared;

A second capacitor (102) is prepared, and the second capacitor (102) is configured such that the capacitance value can be reduced under the action of external air pressure; two second capacitors (102) are prepared;

A first branch is formed by connecting one of the two first capacitors (101) and one of the two second capacitors (102) in series;

Connecting the other of the two first capacitors (101) and the other of the two second capacitors (102) in series to form a second branch;

The first branch is connected in parallel with the second branch.
The method for preparing an air pressure sensor chip according to claim 4, wherein the preparing the first capacitor (101) comprises:

providing a first substrate (1014), and performing ion implantation doping on the first substrate (1014) to form a first electrode (1011);

depositing a first support layer (1015) on the first substrate (1014);

depositing a semiconductor layer on the first support layer (1015) to form a second electrode (1012); and,

Partially etching the first support layer (1015) to expose the first electrode (1011) relative to the second electrode (1012), while the first electrode (1011) and the second electrode (1011) are A first vacuum chamber (1013) is formed between the electrodes (1012).
The method for manufacturing an air pressure sensor chip according to claim 5, wherein the partially etching the first support layer (1015) comprises:

A first etching hole (1016) is formed by etching on the semiconductor layer, and the first etching hole (1016) is connected to the first support layer (1015);

A part of the first support layer (1015) is removed by etching through the first etching hole (1016), so that the first electrode (1011) is exposed relative to the second electrode (1012);

A first sealing layer (1017) is deposited on the semiconductor layer, the first sealing layer (1017) sealing the first etch hole (1016).
The method for fabricating an air pressure sensor chip according to claim 6, characterized in that, after depositing the first sealing layer (1017) on the semiconductor layer, the method further comprises:

A first protective layer (1018) is deposited on the first sealing layer (1017).
The method for preparing an air pressure sensor chip according to any one of claims 4-7, wherein the preparing the second capacitor (102) comprises:

providing a second substrate (1024) on which a second support layer (1025) is deposited;

depositing a semiconductor layer on the second support layer (1025) to form a third electrode (1021);

Partially etching the second support layer (1025) to expose a portion of the third electrode (1021) relative to the second substrate (1024), while the third electrode (1021) and the A second vacuum chamber (1023) is formed between the second substrates (1024);

depositing a third support layer (1026) on the third electrode (1021);

depositing a semiconductor layer on the third support layer (1026) to form a fourth electrode (1022);

Etching to form air through holes (10221) on the fourth electrode (1022);

A part of the third support layer (1026) is removed by etching through the air-permeable through hole (10221), so that the air-permeable through hole (10221) is exposed relative to the third electrode (1021).
The method for manufacturing an air pressure sensor chip according to claim 8, wherein the partially etching the second support layer (1025) comprises:

A second etching hole (1027) is formed by etching on the third electrode (1021), and the second etching hole (1027) is connected to the second supporting layer (1025);

A part of the second support layer (1025) is etched away through the second etching hole (1027), so that a part of the third electrode (1021) is exposed relative to the second substrate (1024) ;

A second sealing layer (1028) is deposited on the third electrode (1021), the second sealing layer (1028) sealing the second etching hole (1027).
The method for manufacturing an air pressure sensor chip according to claim 9, characterized in that, after depositing the second sealing layer (1028) on the third electrode (1021), the method further comprises:

A second protective layer (1029) is deposited on the second sealing layer (1028).