Manufacturing method of airtightness monitoring structure inside vacuum cavity of microelectronic device

Abstract

This invention provides a method for manufacturing a gas tightness monitoring structure for a vacuum cavity of a microelectronic device. The method includes: 1) providing a first substrate, wherein a cavity for accommodating the microelectronic device is formed on a first main surface of the first substrate; 2) providing a second substrate, the second substrate including opposing first and second main surfaces, and forming a film layer on the second substrate; 3) bonding the first main surface of the second substrate to the first main surface of the first substrate, so that the cavity and the second substrate form a gas tightness cavity and simultaneously form a sealed chamber, wherein the sealed chamber is gas tightly isolated from the surrounding environment by the film layer, and the film layer is configured to bulge or indent according to the pressure difference between the sealed chamber and the surrounding environment. Through the manufacturing method of this invention, the gas tightness monitoring structure can be formed simultaneously while encapsulating a microelectronic device. The manufacturing method has advantages such as simple fabrication and low cost.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method for manufacturing a pressure monitoring structure inside a vacuum cavity for use in microelectronic devices. Background Technology

[0002] Micro-Electro-Mechanical Systems (MEMS) technology, developed from microelectronics, is an emerging, multidisciplinary, high-tech field. To protect the internal MEMS devices, MEMS packaging is generally required to be hermetically sealed. This is especially true for MEMS devices such as MEMS gyroscopes and pressure gauges, which require vacuum packaging to achieve their desired performance in a vacuum environment. Similarly, MEMS devices such as infrared sensors also need to encapsulate their sensitive components in a relatively stable vacuum.

[0003] MEMS devices are extremely sensitive to their packaging environment, and certain key parameters can cause them to fail. However, MEMS applications require long-term hermeticity, but in practice, the internal vacuum level of the tiny space encapsulating the MEMS device often decreases over time. This frequently leads to performance degradation of these devices; that is, as the internal vacuum level of the tiny space encapsulating the MEMS device changes, the output values ​​of these devices will change, making the measurement results unable to accurately reflect the measured physical quantity. In other words, the lifespan of these devices is often limited by the degradation of the internal vacuum level of the tiny space encapsulating them. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for manufacturing a vacuum cavity internal airtightness monitoring structure for microelectronic devices, in order to solve the problems of difficulty in maintaining the internal vacuum level of the tiny space used to package microelectromechanical systems and the low reliability of MEMS devices in the vacuum cavity in the prior art.

[0005] To achieve the above and other related objectives, the present invention provides a method for manufacturing a vacuum cavity internal airtightness monitoring structure for microelectronic devices. The method includes: 1) providing a first substrate, wherein a cavity for accommodating a microelectronic device is formed on a first main surface of the first substrate, and a first recess is also formed on the first main surface of the first substrate; 2) providing a second substrate, the second substrate including opposing first and second main surfaces, and forming a film layer on the first main surface of the second substrate; 3) bonding the first main surface of the second substrate to the first main surface of the first substrate, so that the cavity and the second substrate form an airtight cavity, while the first recess is airtightly isolated from the surrounding environment by the film layer, wherein the film layer is configured to bulge or indent according to the pressure difference between the sealed chamber and the surrounding environment.

[0006] Optionally, step 2) includes: 2-1) forming a through hole on the second substrate by photolithography and etching processes, wherein the through hole is aligned with the center of the first recess and the film layer is suspended between the through hole and the sealing chamber.

[0007] Optionally, in step 2), the film layer is integrated with the second substrate, and step 2) includes: 2-1) forming a second recess on the second main surface of the second substrate by photolithography and etching processes, wherein the second recess is aligned with the center of the first recess.

[0008] Optionally, step 2) further includes: 2-2) forming a first material layer on the film layer; 2-3) forming the first material layer into a first patterned layer by photolithography and etching processes, wherein the first patterned layer exposes the film layer located on the recess.

[0009] The present invention also provides a method for manufacturing a vacuum cavity internal airtightness monitoring structure for microelectronic devices, the manufacturing method comprising: 1) providing a first substrate, wherein a cavity for accommodating microelectronic devices is formed on a first main surface of the first substrate;

[0010] 2) The second substrate includes a first main surface and a second main surface opposite to each other. A film layer is formed on the second main surface of the second substrate, and a through hole is also formed on the second substrate; 3) The first main surface of the second substrate is bonded to the first main surface of the first substrate so that the cavity and the second substrate form an airtight cavity, and the space in the through hole is airtightly isolated from the surrounding environment by the film layer. The film layer is configured to bulge or dent according to the pressure difference between the sealed chamber and the surrounding environment.

[0011] Optionally, in step 2), the film layer is integrally formed with the second substrate, and a recess is formed on the surface of the first main surface of the second substrate by photolithography and etching processes.

[0012] Optionally, step 2) includes: 2-1) forming a first material layer on the first main surface of the second substrate; 2-2) forming the first material layer as a first patterned layer by photolithography and etching processes.

[0013] Optionally, step 3) includes: 3-1) forming a second material layer on the first main surface of the first substrate; 3-2) forming the second material layer into a second patterned layer by photolithography and etching processes, wherein the first patterned layer and the second patterned layer are aligned and bonded to form a bonding layer, wherein the bonding layer is an Al-Ge eutectic bonding layer.

[0014] Optionally, in step 2), the through hole is formed on the second substrate by photolithography and etching processes. The film layer is made of a different material from the second substrate. The film layer is a single layer or a composite layer of materials selected from the following materials deposited by low-pressure chemical vapor deposition: polysilicon, silicon oxide and silicon nitride.

[0015] Optionally, the bonding layer is formed by direct bonding between the interface of the first substrate and the second substrate.

[0016] As described above, the method for manufacturing the airtightness monitoring structure inside the vacuum cavity of the present invention has the following beneficial effects:

[0017] A method for manufacturing a gas tightness monitoring structure inside a vacuum cavity for microelectronic devices is provided. This method can package a MEMS device and simultaneously form a gas tightness monitoring structure inside the package structure to achieve real-time monitoring of the internal vacuum level of a tiny space. The manufacturing method has advantages such as simple fabrication and low cost. Attached Figure Description

[0018] Figures 1-4 The diagram shows the structural schematics of each step in the manufacturing method of the airtightness monitoring structure inside the vacuum cavity of a microelectronic device, which is an embodiment of the present invention.

[0019] Figures 5-7 The diagram shows the structural schematics of each step in the manufacturing method of the airtightness monitoring structure inside the vacuum cavity of a microelectronic device, which is an embodiment of the present invention.

[0020] Figure 8A and Figure 8B The diagram shows the working operation of the airtightness monitoring structure inside the vacuum cavity of a microelectronic device according to the present invention, which performs real-time monitoring.

[0021] Component designation explanation

[0022] 100 First substrate

[0023] 100a First Main Face

[0024] 100b Second Main Face

[0025] 102 Airtight Cavity

[0026] 104 Microelectromechanical devices

[0027] 105 First recess

[0028] 106, 206 Sealed Chambers

[0029] 200 Second substrate

[0030] 200a First Main Face

[0031] 200b Second Main Face

[0032] 202 Through Hole

[0033] 204 Second recess

[0034] 300a and 300b film layers

[0035] 400 bonded layers

[0036] 410 First Graphical Layer

[0037] 420 Second Graphics Layer Detailed Implementation

[0038] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0039] In the detailed description of embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0040] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for devices in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it may be the only layer between the two layers, or there may be one or more layers in between.

[0041] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0042] In this invention, the term "substrate" may refer to substrates commonly used in the semiconductor manufacturing field.

[0043] As used herein, although the terms “first,” “second,” “third,” etc., may describe various elements, components, areas, layers, and / or segments, none of them are limited by these terms. These terms are used only to distinguish one element, component, area, material, layer, or segment from another. Therefore, without departing from the teachings herein, “first element,” “first component,” “first area,” “first material,” “first layer,” or “first segment” discussed below may be referred to as a second element, second component, second area, second material, second layer, or second segment.

[0044] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0045] To address the challenge of maintaining a consistently high vacuum level within the small space occupied by MEMS devices in a vacuum environment, which negatively impacts the reliability of MEMS devices, this invention provides a method for manufacturing an airtightness monitoring structure for the interior of a vacuum cavity in a microelectronic device. The manufacturing method includes at least: a method for manufacturing an airtightness monitoring structure for the interior of a vacuum cavity in a microelectronic device, and a method for manufacturing an airtightness monitoring structure for the interior of a vacuum cavity in a microelectronic device. The manufacturing method includes: 1) providing a first substrate, wherein a cavity for accommodating a microelectronic device is formed on a first main surface of the first substrate, and a first recess is also formed on the first main surface of the first substrate; 2) providing a second substrate, wherein the second substrate includes opposing first and second main surfaces, and a film layer is formed on the first main surface of the second substrate; 3) bonding the first main surface of the second substrate to the first main surface of the first substrate, thereby forming an airtight cavity between the cavity and the second substrate, while simultaneously ensuring that the first recess is airtightly isolated from the surrounding environment by the film layer, wherein the film layer is configured to bulge or indent according to the pressure difference between the sealed chamber and the surrounding environment.

[0046] The present invention also provides another method of manufacturing the method, comprising: 1) providing a first substrate, wherein a cavity for accommodating a microelectronic device is formed on a first main surface of the first substrate; 2) providing a second substrate, the second substrate including opposing first and second main surfaces, wherein a film layer is formed on the second main surface of the second substrate, the film layer forming an airtight contact with the second main surface of the second substrate, and a through hole is also formed on the second substrate; 3) bonding the first main surface of the second substrate to the first main surface of the first substrate, such that the cavity forms an airtight cavity with the second substrate, while the space within the through hole is airtightly isolated from the surrounding environment by the film layer, wherein the film layer is configured to bulge or dent according to the pressure difference between the sealed chamber and the surrounding environment.

[0047] The manufacturing method briefly outlined above provides a hermeticity monitoring structure that can pre-measure the characteristics of MEMS devices under different vacuum levels and monitor the internal vacuum level of tiny spaces within them in real time. The manufacturing method is simple and efficient. It achieves vacuum packaging of MEMS devices and provides a hermeticity detection structure for real-time monitoring of the internal vacuum level of tiny spaces within them. The method is simple and has low manufacturing cost, ensuring the performance of MEMS devices while improving their lifespan.

[0048] See afterward. Figures 1 to 7 The present invention specifically describes the manufacturing method of the airtightness monitoring structure for the vacuum cavity of microelectronic devices.

[0049] Example 1

[0050] like Figures 1-4As shown, this embodiment provides a method for manufacturing a gas tightness monitoring structure inside a vacuum cavity for microelectronic devices. The manufacturing method specifically includes the following steps:

[0051] First, see Figure 1 In step 1), a first substrate 100 is provided. The first substrate has a first main surface 100a and a second main surface 100b. A cavity for accommodating microelectronic devices is formed on the first main surface 100a of the first substrate. Preferably, the first substrate 100 may be a silicon substrate.

[0052] Then, in step 2), a second substrate 200 is provided, the second substrate including opposing first main surface 200a and second main surface 200b, and a film layer is formed on the second substrate. Figure 2 This diagram illustrates the structure formed on the second substrate in step 2) of this embodiment, where a film layer 300a is formed on the first main surface 200a of the second substrate 200, and the film layer forms an airtight contact with the first main surface 100 of the second substrate. Before or after performing step 2), the manufacturing method may further include forming a first recess 105 on the first main surface 100a of the first substrate. Specifically, step 2) includes at least: 2-1) forming a through-hole 202 on the second substrate 200 using photolithography and etching processes, wherein the through-hole is aligned with the center of the first recess 105 and the film layer is suspended between the through-hole and the first recess. Alternatively, in step 2), the film layer is integrally formed with the second substrate 200, and step 2) includes: 2-1) forming a second recess 204 on the second main surface 200b of the second substrate using photolithography and etching processes, wherein the second recess is aligned with the center of the first recess 105.

[0053] Preferably, the second substrate 200 can be a silicon substrate, SOI substrate, germanium-silicon substrate, germanium substrate, gallium nitride substrate, SiC substrate, etc., or it can be an insulating substrate such as quartz, sapphire, or glass. The film layer 300a can have the same material as the second substrate or a different material. The film layer can be a single layer or a composite layer composed of one of the following materials: polycrystalline silicon, silicon oxide, and silicon nitride. For example, the film layer can be a single layer of polycrystalline silicon or a composite layer of silicon oxide and silicon nitride. As an example, the film layer can be grown from the second substrate 200 using a low-pressure chemical vapor deposition (LPCVD) process. The film layer can be deposited as a polycrystalline silicon thin film with a thickness of 5 micrometers.

[0054] Next, proceed to step 3), see [link to step 3]. Figure 4The first main surface 200a of the second substrate is bonded to the first main surface 100a of the first substrate to form a bonding layer 400 between the first substrate and the second substrate. In this embodiment, the step of forming the bonding layer involves forming an hermetically tight cavity 102 between the cavity on the surface of the first main surface 100a of the first substrate and the second substrate, while simultaneously isolating the first recess 105 from the surrounding environment by the film layer 300a. In this embodiment, the bonding layer 400 can be formed as a eutectic bonding layer. Figure 2 As shown, prior to step 3), the manufacturing method further includes: 2-2) forming a first material layer on the film layer 300a; 2-3) forming the first material layer into a first patterned layer 410 by photolithography and etching processes, the first patterned layer exposing the film layer located above the second recess. In the example where the first material layer is an aluminum layer, after step 2-1), at least the following steps are included: forming an Al layer on the first main surface 200a of the second substrate by physical vapor deposition (PVD) process, and then etching the Al layer into a patterned Al layer by photolithography and etching processes. In this embodiment, the shape and thickness of the first patterned layer can be determined according to the bonding requirements between the first substrate and the second substrate.

[0055] Specifically, step 3) includes: 3-1) forming a second material layer on the first main surface 100a of the first substrate; 3-2) forming the second material layer into a second patterned layer 420 by photolithography and etching processes, such as... Figure 3 As shown. For simplicity, only a schematic diagram of the structure presented here after step 2-1) of this embodiment, showing the formation of a second patterned layer on the first main surface of the first substrate where the sealing chamber is provided, is shown. In other examples, a second patterned layer of the desired shape can be formed on the first main surface of the first substrate according to step 3) described herein. Specifically, the first patterned layer 410 and the second patterned layer 420 are aligned and bonded to form a bonding layer 400, thereby obtaining the airtightness monitoring structure. Figure 4 As shown, in the aforementioned airtightness monitoring structure, the film layer 300a is suspended between the sealed chamber 106 and the through hole on the second substrate, and is configured to bulge or dent depending on the pressure difference between the sealed chamber 106 and the surrounding environment. The internal air pressure of the sealed chamber 106 is positively correlated with the internal air pressure of the airtight cavity 102, and the airtightness of the airtight cavity can be monitored in real time based on the pressure change of the sealed chamber, thus easily allowing for real-time measurement of the vacuum level of the tiny space where the MEMS is located. The method for real-time monitoring of the internal vacuum level of this tiny space will be described in detail in conjunction with Embodiment 2 below.

[0056] Since the hermetic cavity 102 formed on the surface of the first main surface 100a of the first substrate and the sealed chamber are formed simultaneously on the same chip under the same conditions, the performance of the MEMS device in the vacuum cavity and the internal air pressure P of the sealed chamber can be determined according to the predetermined performance of the MEMS device in the vacuum cavity and the internal air pressure P of the sealed chamber. in The internal vacuum level used to house the MEMS device is calibrated to ensure that its output value more accurately reflects the measured physical quantity. In this embodiment, the conditions for eutectic bonding between the first patterned layer 410 and the second patterned layer 420 can be set according to actual bonding accuracy, vacuum level, and other requirements.

[0057] As an example, the second patterned layer 420 may be a patterned Ge layer, such that the bonding layer 400 between the first substrate 100 and the second substrate 200 may be an Al-Ge eutectic bonding layer. Forming a patterned Ge layer on the first main surface 100a of the first substrate 100 includes at least: forming the Ge layer on the first main surface 100a of the first substrate using a physical vapor deposition (PVD) process, followed by etching the Ge layer into a patterned Ge layer using photolithography and etching processes. Although the formation process of the bonding layer has been described above using an Al-Ge eutectic bonding layer as an example, the type of bonding layer of the present invention is not limited thereto, and also includes other binary eutectic bonding layers, such as gold-silicon eutectic bonding layers. As an alternative, the first substrate 100 and the second substrate 200 may be directly bonded; that is, the bonding layer 400 is formed by interdiffusion of materials at the bonding interface between the first substrate 100 and the second substrate 200, without forming a first patterned layer 410 and a second patterned layer 420 composed of materials other than the substrate material.

[0058] Example 2

[0059] like Figures 5 to 7 , Figure 8A and 8B As shown, this embodiment provides a method for manufacturing a vacuum cavity internal airtightness monitoring structure for microelectronic devices. The basic steps are as described in Embodiment 1, except that the difference from Embodiment 1 is that: by forming a bonding layer, the film layer disposed on the second substrate airtightly isolates the sealed chamber located on the second substrate from the surrounding environment.

[0060] Specifically, see Figure 5The diagram shows the structure of the film layer formed on the second substrate in step 2) of this embodiment. The film layer 300b is formed on the second main surface 200b of the second substrate 200. Step 2) includes: 2-1) forming a through hole 202 on the first main surface 200a of the second substrate. The through hole is airtightly isolated from the surrounding environment by the film layer 300b disposed on the second main surface 200b of the second substrate. The film layer forms an airtight contact with the second main surface 200b of the second substrate.

[0061] Next, proceed to step 3), see [link to step 3]. Figure 7 The first main surface of the second substrate is bonded to the first main surface of the first substrate to form a bonding layer 400 between the first substrate and the second substrate. Through the step of forming the bonding layer, the cavity and the first main surface 100a of the second substrate form an airtight cavity 102, while the space within the through hole 202 is airtightly isolated from the surrounding environment by the film layer 300b. The bonding layer 400 in this embodiment can be the same as or similar to the bonding layer described in Embodiment 1. Depending on the needs, the bonding layer can be a eutectic bonding layer, or it can be formed by the mutual diffusion of materials at the bonding interface between the first substrate 100 and the second substrate 200. The conditions for eutectic bonding between the first patterned layer 410 and the second patterned layer 420 can be set according to actual bonding accuracy, vacuum requirements, etc. Optionally, after step 2-1), step 2) includes: 2-2) forming a first material layer on the first main surface 100a of the second substrate; 2-3) forming the first material layer into a first patterned layer 410 by photolithography and etching processes, such as... Figure 6 As shown.

[0062] Optionally, in the example where the bonding layer 400 is a eutectic bonding layer, step 3) includes: 3-1) forming a second material layer on the first main surface 100a of the first substrate; 3-2) forming the second material layer into a second patterned layer 420 by photolithography and etching processes, such as... Figure 6 As shown. For simplicity, only a schematic diagram of the structure formed in step 3) of this embodiment is shown here. In other examples, a second patterned layer of the desired shape can be formed on the first main surface of the first substrate according to the method steps described herein. Specifically, the first patterned layer 410 and the second patterned layer 420 are aligned and bonded to form a bonding layer 400, thereby obtaining the airtightness monitoring structure. See also Figure 8A and Figure 8BIn the aforementioned airtightness monitoring structure, the membrane layer 300b is configured to bulge or indent based on the pressure difference between the sealed chamber 106 and the surrounding environment. The internal air pressure of the sealed chamber 106 is positively correlated with the internal air pressure of the airtightness cavity 102. Since the airtightness cavity 102 formed on the surface of the first main surface 100a of the first substrate and the sealed chamber are formed simultaneously on the same chip under the same conditions, the performance of the MEMS device in the vacuum cavity and the internal air pressure P of the sealed chamber can be determined based on a predetermined correlation. in The relationship is used to calibrate the internal vacuum level used to house MEMS devices so that the output value can more accurately reflect the measured physical quantity.

[0063] Specifically, see Figure 8A and Figure 8B When the internal air pressure P of the sealed chamber 206 in The external atmospheric pressure P of the chip out When differences occur, film layer 300b will deform by protrusion or depression. For example... Figure 8A As shown, when the internal air pressure P of the sealed chamber 206 in The external atmospheric pressure P is greater than that of the chip. out At this time, the membrane layer 300b will bulge and deform towards the environment, that is, the membrane layer will dent and deform towards the interior of the sealing chamber. For example... Figure 8B As shown, when the internal air pressure P of the sealed chamber 206 in The external atmospheric pressure P is less than that of the chip. out At this time, the membrane layer 300b will bulge and deform inward toward the sealing chamber 206. The thickness and size of the membrane layer can be designed according to the gas pressure range to be monitored. The size, geometry, and other physical parameters of the membrane layer can be designed based on simulation calculations. In particular, the membrane layer can be circular, polygonal, or other shapes adapted to the substrate. For example, in an example where the membrane layer has a circular shape, the membrane layer has a diameter of 1 mm to 10 mm and a thickness of 10 micrometers (μm) to 20 μm.

[0064] The deformation mode and amount of the film layer 300b can be precisely measured using methods such as laser morphology monitoring microscopy and probe-type profilometer. By measuring the deformation of the film layer and comparing the measurement results with predetermined parameters such as the film layer's size and geometry, the difference P between the internal air pressure of the sealed chamber and the external air pressure of the chip can be determined. d =P out -P in Due to the external ambient air pressure P out The internal air pressure P of the sealed chamber can be easily measured. in =P out -P dThe hermetic cavity 102 formed on the surface of the first main surface 100a of the first substrate and the sealed chamber are formed simultaneously on the same chip under the same conditions, and the internal air pressure P of the sealed chamber is... in The internal air pressure P of the vacuum cavity on the first substrate c They are strongly correlated; in some cases, the internal air pressure P of both is similar. in With P c They can be equal. Therefore, by pre-determining the performance of the microelectronic devices (e.g., MEMS) within the vacuum cavity and the internal gas pressure P of the sealed chamber... in Based on the output of the microelectronic devices within the vacuum cavity, the true value of the measured physical quantity can be accurately obtained. Therefore, even when the gas pressure inside the MEMS vacuum cavity changes, the reliability of its performance can still be guaranteed, effectively extending the lifespan of the MEMS device.

[0065] As described above, the manufacturing method of the airtightness monitoring structure inside the vacuum cavity for microelectronic devices of the present invention has the following advantages: the airtightness monitoring structure can be formed at the same time as the MEMS device is packaged, and the manufacturing method has the advantages of simple manufacturing and low cost.

[0066] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0067] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for manufacturing a vacuum chamber internal hermeticity monitoring structure for a microelectronic device, characterized by, The method comprises: 1) providing a first substrate, a cavity for accommodating a microelectronic device is formed on a first main surface of the first substrate, and a first recess is also formed on the first main surface of the first substrate; 2) providing a second substrate, the second substrate comprises opposite first and second main surfaces, and a film layer is formed on the first main surface of the second substrate; 3) bonding the first main surface of the second substrate to the first main surface of the first substrate, so that the cavity and the second substrate form a hermetic cavity, and the first recess is hermetically blocked by the film layer and the surrounding environment, the film layer is configured to be deformed in bulging or sagging according to the air pressure difference between the first recess and the surrounding environment, and the internal air pressure of the hermetic cavity and the sealed first recess is positively correlated.

2. The method of manufacturing an air barrier monitoring structure according to claim 1, wherein, Step 2) comprises: 2-1) forming a through hole on the second substrate by a photolithography process and an etching process, the through hole is centered aligned with the first recess and the film layer is suspended between the through hole and the first recess.

3. The method of manufacturing an air barrier monitoring structure of claim 1, wherein: In step 2), the film layer is formed integrally with the second substrate, and step 2) comprises: 2-1) forming a second recess on the second main surface of the second substrate by a photolithography process and an etching process, the second recess is centered aligned with the first recess.

4. The method of manufacturing an air barrier structure according to claim 1, wherein Step 2) further comprises: 2-2) forming a first material layer on the film layer; 2-3) forming the first material layer into a first patterned layer by a photolithography process and an etching process, the first patterned layer exposes the film layer on the recess.

5. A method for manufacturing a vacuum chamber internal atmosphere tightness monitoring structure for a microelectronic device, characterized by, The method comprises: 1) providing a first substrate, a cavity for accommodating a microelectronic device is formed on a first main surface of the first substrate; 2) providing a second substrate, the second substrate comprises opposite first and second main surfaces, and a film layer is formed on the second main surface of the second substrate, and a through hole is also formed on the second substrate; 3) bonding the first main surface of the second substrate to the first main surface of the first substrate, so that the cavity and the second substrate form a hermetic cavity, and the space in the through hole is hermetically blocked by the film layer and the surrounding environment, the film layer is configured to be deformed in bulging or sagging according to the air pressure difference between the through hole and the surrounding environment; the internal air pressure of the hermetic cavity and the sealed through hole is positively correlated.

6. The method of manufacturing an air barrier structure according to claim 5, wherein Step 2) comprises: 2-1) forming a first material layer on the first main surface of the second substrate; 2-2) forming the first material layer into a first patterned layer by a photolithography process and an etching process.

7. The method of manufacturing an air barrier structure according to claim 4 or 6, wherein In step 3) comprises: 3-1) forming a second material layer on the first main surface of the first substrate; 3-2) forming the second material layer into a second patterned layer by a photolithography process and an etching process, the first patterned layer and the second patterned layer are aligned one by one and bonded to form a bonding layer, wherein the bonding layer is an Al-Ge eutectic bonding layer.

8. The method of manufacturing an air barrier structure of claim 5, wherein: In step 2), the through hole is formed on the second substrate by a photolithography process and an etching process, the film layer and the second substrate have different materials, wherein the film layer is a single layer or a composite layer composed of one selected from the following materials: polysilicon, silicon oxide and silicon nitride, which is deposited by a low pressure chemical vapor deposition process.

9. The method of manufacturing an air barrier structure according to claim 1 or 5, wherein A bonding layer is formed by direct bonding between the interface between the first substrate and the second substrate.

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