CN117945335A - Micro-electromechanical system package and method of manufacturing the same - Google Patents

Abstract

The invention discloses a micro-electromechanical system package and a manufacturing method thereof, wherein the micro-electromechanical system package comprises a first MEMS package and a second MEMS package, and the second MEMS package is transversely separated from the first MEMS package; the first MEMS package includes: a first element substrate including a first MEMS element; a first cover substrate bonded to the first element substrate, wherein the first cover substrate encloses a first cavity and a vent, the vent being connected to the first cavity; and a first sealing layer filled in at least a portion of the vent hole, wherein the first sealing layer is disposed between the first element substrate and the first cover substrate; the second MEMS package includes: a second element substrate comprising a second MEMS element; and a second cover substrate bonded to the second component substrate, wherein the second cover substrate encloses the second cavity; the first cavity has a first pressure and the second cavity has a second pressure different from the first pressure.

Description

Micro-electromechanical system package and method of manufacturing the same

Technical Field

The invention relates to a microelectromechanical system package and a method of manufacturing the same.

Background

Microelectromechanical systems (Micro-Electro-MECHANICAL SYSTEM, MEMS) elements, such as accelerometers, gyroscopes, pressure sensors and microphones, have been widely used in many modern electronic components. For example, inertial measurement units (inertial measurement unit, IMU) consisting of accelerometers and/or MEMS gyroscopes are common in tablet computers, automobiles, or smartphones. In some applications, various MEMS elements need to be integrated into one MEMS package. However, for MEMS elements that require different pressures, the MEMS elements need to be packaged separately at different ambient pressures and then integrated into one MEMS package. Therefore, the entire packaging process is complicated, and the MEMS package has a large footprint (footprint).

Disclosure of Invention

In view of the above, the present invention provides a microelectromechanical system (MEMS) package and a method of manufacturing the same, which overcome the disadvantages of the prior art.

The invention provides the following technical scheme for achieving the purpose:

A microelectromechanical system package comprising a first MEMS package and a second MEMS package, the second MEMS package being laterally spaced from the first MEMS package; the first MEMS package includes: a first element substrate including a first MEMS element; a first cover substrate bonded to the first element substrate, wherein the first cover substrate encloses a first cavity and a vent hole, the vent hole being connected to the first cavity; and a first sealing layer filling at least a portion of the vent hole, wherein the first sealing layer is disposed between the first element substrate and the first cover substrate; the second MEMS package includes: a second element substrate comprising a second MEMS element; and a second cover substrate bonded to the second element substrate, wherein the second cover substrate encloses the second cavity; wherein the first cavity has a first pressure and the second cavity has a second pressure different from the first pressure.

The invention also provides a manufacturing method of the MEMS package, which comprises the following steps: providing a cover substrate comprising a first groove, a second groove and a third groove, wherein the first groove is connected to the third groove, and the first groove and the third groove are transversely separated from the second groove, and the depth of the first groove and the depth of the second groove are larger than the depth of the third groove; covering the first, second and third grooves with the cover substrate under an ambient pressure to form a first, second and third cavity; removing the cover substrate adjacent to one end of the third groove to form a vent hole; flowing gas through the vent at another ambient pressure different from the ambient pressure; and filling a sealing layer into the vent after the gas flows through the vent.

According to some embodiments of the invention, the pressure of the first cavity may be controlled independently of the pressure of the second cavity. In addition, the pressure of the first cavity may be controlled by flowing gas through the vent. Therefore, the entire packaging process is simplified and the footprint of the MEMS package is smaller compared to the prior art.

Drawings

For a better understanding of the present invention, reference should be made to the drawings and to the detailed description thereof when read in light of the accompanying drawings. Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings, wherein the present embodiments are illustrated in the accompanying drawings. Furthermore, for the sake of clarity, various features in the drawings may not be drawn to actual scale, and therefore the dimensions of some of the features in some of the drawings may be exaggerated or reduced in size.

FIG. 1 is a schematic top view of a microelectromechanical system (MEMS) package in accordance with an embodiment of the invention.

FIG. 2 is a schematic cross-sectional view of the MEMS package along the section line A-A' of FIG. 1 according to an embodiment of the present invention.

FIG. 3 is a schematic top view of different types of vents in a first MEMS package of an embodiment of the present invention.

Fig. 4 to 10 are schematic cross-sectional views of the MEMS package manufacturing method according to the embodiment of the invention at different manufacturing stages.

The reference numerals are explained as follows:

MEMS package

Substrate base

102-1

102-2

First MEMS package

First MEMS package

First MEMS package

First MEMS package

Second MEMS package

Cover substrate

Top surface of 120-2

First cover substrate

Second cover substrate

First cavity

Second cavity

124. Vent

124A

124B

124C

Outside opening

Inside opening

Projecting portion

Projecting portion

First lower cavity

Second lower cavity

134A

134B

Sealing layer

First sealing layer

Second sealing layer

End face

Support substrate

Interconnect layer

Protective layer

Element substrate

First element substrate

Second element substrate

Bonding material

First MEMS element

Second MEMS element

Bonding dielectric layer

Bonding dielectric layer

Bonding dielectric layer

222. Conductive layer

222A. conductive layer

222B. conductive layer

Step (a)

Step (a)

Step (iii)

Step (v)

Step (a)

Step (ii)

Step (a.) the method

First groove

Second groove

Third groove

Third cavity

426

First region 452

452A

452B. first region

452C. first region

452D

454. Second zone

D1.first depth

D2. second depth

D3.third depth

Detailed Description

In order to make the features of the present invention comprehensible, embodiments accompanied with figures are described in detail below. The invention provides several different embodiments that can be used to implement different features of the invention. For simplicity of explanation, the invention also describes examples of specific components and arrangements. These examples are provided for the purpose of illustration only and are not intended to be limiting in any way. For example, the following description of a first feature being formed on or over a second feature may refer to the first feature being in direct contact with the second feature, or may refer to other features being present between the first and second features, such that the first and second features are not in direct contact. Furthermore, various embodiments of the present invention may use repeated reference characters and/or textual notations. These repeated reference characters and notations are used to make the description more concise and clear, rather than to indicate a relationship between different embodiments and/or configurations.

In addition, for the spatially related narrative terms mentioned in the present invention, for example: when "under", "low", "lower", "upper", "top", "bottom" and the like, for ease of description, the description is used to describe one element or feature's relative relationship to another element(s) or feature(s) in the figures. In addition to the orientation shown in the drawings, these spatially dependent terms are also used to describe possible orientations of the semiconductor device in use and operation. With respect to the orientation of the semiconductor device (rotated 90 degrees or other orientations), the spatially relative descriptors describing the orientation should also be interpreted in a similar manner.

Although the invention has been described in the language of first, second, third, etc., to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section, which does not itself imply any preceding ordinal number or order of arrangement or method of manufacture of the element. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the scope of the embodiments of the present invention.

The terms "about" or "substantially" as referred to herein generally mean within 20%, preferably within 10%, and more preferably within 5%, or within 3%, or within 2%, or within 1%, or within 0.5% of a given value or range. It should be noted that the amounts provided in the specification are about amounts, i.e., without a specific recitation of "about" or "substantially," the meaning of "about" or "substantially" may still be implied.

Furthermore, the terms "coupled to" and "electrically connected" as used herein include any direct or indirect means of electrical connection. Thus, if a first element is described herein as being coupled or electrically connected to a second element, this means that the first element can be directly connected to the second element or can be indirectly connected to the second element through other elements or other connection means.

Although the following embodiments are described to describe the technical solution of the present invention, the inventive principles of the present invention can be applied to other embodiments. Furthermore, specific details are omitted so as not to obscure the spirit of the present invention, and such omitted details are within the knowledge of those skilled in the art.

FIG. 1 is a schematic top view of a microelectromechanical system (MEMS) package according to some embodiments of the invention. Referring to fig. 1, a MEMS package 100 includes a MEMS element such as an accelerometer or a gyroscope, but is not limited thereto. In some embodiments, the MEMS package 100 includes a base substrate 102, and at least two sub-MEMS packages, such as a first MEMS package 104 and a second MEMS package 106, disposed on the same base substrate 102, with the first MEMS package 104 and the second MEMS package 106 being laterally (e.g., in the x-direction) spaced apart from each other.

The first MEMS package 104 includes a first MEMS element (not shown), a first cover substrate 120a, a first cavity 122a, a vent 124, and a first sealing layer 140a. The first MEMS element overlaps the first cavity 122a and at least a portion of the first MEMS element, such as a proof mass (proof mass) or cantilever beam (cantilever beam), may move, vibrate and/or rotate in the space formed by the first cavity 122a during operation of the first MEMS package 104. The first cavity 122a is enclosed by the first cover substrate 120a and the first sealing layer 140a. In some embodiments, the first cavity 122a has a predetermined pressure (e.g., a first pressure), the vent 124 is connected to a sidewall of the first cavity 122a, the vent 124 includes a straight passage that passes laterally through the first cover substrate 120a, and at least a portion of the vent 124 is filled with the first sealing layer 140a.

In some embodiments, the first MEMS package 104 further includes a first element substrate (not shown) disposed below the first cap substrate 120a and the first cavity 122a in a vertical direction (e.g., in a Z-direction). The first element substrate includes a protruding portion 130a, the protruding portion 130a being a continuous structure extending downward from the body of the first element substrate and bonded to the base substrate 102. A portion of the protruding portion 130a overlaps the first cavity 122a and is spaced laterally (e.g., in the x-direction) from the vent hole 124.

Referring to fig. 1, the second MEMS package 106 includes a second MEMS element (not shown), a second cap substrate 120b, a second cavity 122b, and a second sealing layer 140b. The second MEMS element overlaps the second cavity 122b and at least a portion of the second MEMS element, such as a proof mass or cantilever beam, may move, vibrate and/or rotate in the space formed by the second cavity 122b during operation of the second MEMS package 106. The second cavity 122b is enclosed by the second cover substrate 120b and the second sealing layer 140b. In some embodiments, the second cavity 122b has a predetermined pressure (e.g., a second pressure), and the second MEMS package 106 further includes a second element substrate (not shown) disposed below the second cap substrate 120b and the second cavity 122 b. The second element substrate includes a protruding portion 130b, the protruding portion 130b being a continuous structure extending downward from the body of the second element substrate and bonded to the base substrate 102. The protruding portion 130b surrounds the periphery of the second cavity 122b, so the protruding portion 130b does not overlap the second cavity 122b when viewed from a top view.

Fig. 2 is a schematic cross-sectional view of a MEMS package taken along section line A-A' in fig. 1, according to some embodiments of the invention. Referring to fig. 2, the first MEMS package 104 and the second MEMS package 106 share the same base substrate 102. The base substrate 102 includes a support substrate 202 and an interconnect layer 204 disposed on the support substrate 202. In some embodiments, the support substrate 202 is a semiconductor substrate for accommodating semiconductor elements such as transistors, but is not limited thereto. In some embodiments, the support substrate 202 may be an insulating substrate without any active or passive elements. Interconnect layer 204 includes an inter-metal dielectric (INTER METAL DIELECTRIC, IMD) layer and a plurality of conductive interconnect lines and vias. The conductive interconnect lines and vias have a predetermined design layout and may be electrically coupled to the first MEMS element 212 and the second MEMS element 216 disposed on the interconnect layer 204. A protective layer 206 may be disposed on the interconnect layer 204 to protect portions of the interconnect layer 204.

In some embodiments, the first element substrate 210a includes a first MEMS element 214 having an accelerometer or gyroscope. The first element substrate 210a may be bonded to the base substrate 102 by a bonding material 212 disposed under the protruding portion 130 a. Bonding material 212 may include eutectic bonding material (eutectic bonding material) including, but not limited to, au-Ge, au-Si, al-Ge, al-Si, or combinations thereof. The first lower cavity 132a may be defined by a protruding portion 130a disposed below the first MEMS element 214 and surrounded by the protruding portion 130 a.

In some embodiments, the first cover substrate 120a is disposed over the first element substrate 210a. In some embodiments, the first cover substrate 120a may be bonded to the first element substrate 210a by a bonding dielectric layer 220a disposed on a surface of the first cover substrate 120 a. The bonding dielectric layer 220a may be a conformal layer disposed on the bottom surface of the first cap substrate 120a and between the first element substrate 210a and the first cap substrate 120 a. The bonding dielectric layer 220a and the first element substrate 210a enclose the first cavity 122a and the vent 124. The height of the first cavity 122a is greater than the height of the vent 124.

A conductive layer 222a, which may be a patterned conductive layer, is disposed on the top surface of the first cap substrate 120a, electrically coupled to conductive interconnect lines and vias in the first MEMS element 214 and/or the interconnect layer 204.

The first sealing layer 140a is disposed on a sidewall of the first cover substrate 120a, or further disposed on a sidewall of the first element substrate 210 a. A portion of the first sealing layer 140a may fill the vent 124, and the portion of the first sealing layer 140a may have an end face 142 proximate the first cavity 122 a. In some embodiments, the end face 142 of the first sealing layer 140a is disposed in the vent 124 and does not extend into the first cavity 122 a. In other words, the end face 142 of the first sealing layer 140a is laterally (e.g., in the x-direction) spaced from the first cavity 122 a. In some embodiments, a portion of the first sealing layer 140a may fill in the first gap 134a between the interconnect layer 204 and the first element substrate 210 a.

The second element substrate 210b includes a second MEMS element 216 having an accelerometer or gyroscope, and the type of the second MEMS element 216 is different from the type of the first MEMS element 214. For example, where the first MEMS element 214 is a gyroscope enclosed in a cavity having a relatively low pressure, the second MEMS element 216 may be an accelerometer enclosed in a cavity having a relatively high pressure, rather than a gyroscope. The second element substrate 210b may be bonded to the base substrate 102 by a bonding material 212 disposed under the protruding portion 130 b. The bonding material 212 may include eutectic bonding materials including, but not limited to, au-Ge, au-Si, al-Ge, al-Si, or combinations thereof. The second lower cavity 132b may be defined by a protruding portion 130b disposed below the second MEMS element 216 and surrounded by the protruding portion 130 b.

The second cover substrate 120b is disposed over the second element substrate 210b. In some embodiments, the second cover substrate 120b may be bonded to the second element substrate 210b by a bonding dielectric layer 220b disposed on a surface of the second cover substrate 120 b. The bonding dielectric layer 220b may be a conformal layer disposed on the bottom surface of the second cap substrate 120b and between the second element substrate 210b and the second cap substrate 120 b. The bonding dielectric layer 220b and the second element substrate 210b enclose the second cavity 122b. The height of the second cavity 122b is greater than the height of the vent 124.

A conductive layer 222b, which may be a patterned conductive layer, is disposed on the top surface of the second cap substrate 120b, electrically coupled to conductive interconnect lines and vias in the second MEMS element 216 and/or the interconnect layer 204.

The second sealing layer 140b is disposed on a sidewall of the second cover substrate 120b, or further disposed on a sidewall of the second element substrate 210 b. In some embodiments, a portion of the second sealing layer 140b may fill in the second gap 134b between the interconnect layer 204 and the second element substrate 210 b. In some embodiments, the second sealing layer 140b has the same composition as the first sealing layer 140a, and both may be formed simultaneously by the same deposition and etching processes.

According to some embodiments of the invention, the first cavity 122a has a predetermined pressure, such as a first pressure (or first air pressure), that is different from a predetermined pressure, such as a second pressure (or second air pressure), of the second cavity 122 b. By flowing gas into or out of the first cavity 122a through the vent 124, the pressure of the first cavity 122a may be controlled independently of the pressure of the second cavity 122 b. In the case where the first MEMS element is required to operate at a relatively high pressure, such as a pressure greater than or equal to 1.0 standard atmospheric pressure (atm), and the second MEMS element is required to operate at a relatively low pressure, such as a pressure less than 1.0atm, gas may flow from the ambient environment into the first cavity 122a through the vent 124. When the pressure of the first cavity 122a is substantially equal to the pressure of the surrounding environment, the vent 124 is sealed by the first sealing layer 140 a.

Fig. 3 is a schematic top view of different types of vents in a first MEMS package according to some embodiments of the invention. Referring to fig. 3, the vent holes in the first MEMS package 104 are not limited to the straight-shaped vent holes as shown in fig. 1, and may be of different types, such as the vent holes 124a, 124b, 124c shown in fig. 3.

For the vent 124a of the first MEMS package 104a, the vent 124a includes an outer opening 126 distal to the first cavity 122a and an inner opening 128 proximal to the first cavity 122a. In this case, the vent 124a is not a straight shape, but a nonlinear shape (non-LINEAR SHAPE) including several channels extending in the X-direction or the Y-direction and connected to each other by end portions. During the formation of the first sealing layer 140a, the end face 142 of the first sealing layer may be controlled such that the end face 142 is easily terminated in the vent 124a, because the vent 124a composed of channels perpendicular to each other may prevent the generated solid product from entering the first cavity 122a.

For the vent 124b of the first MEMS package 104b, the vent 124b is not a straight shape, but a nonlinear shape, such as a saw tooth shape. During formation of the first sealing layer 140a, the end face 142 of the first sealing layer may be controlled such that the end face 142 is easily terminated at the vent 124b, because the zigzag-shaped vent 124b may prevent the generated solid product from entering the first cavity 122a.

For the vent 124c of the first MEMS package 104c, the vent 124c is not straight, but is non-linear, such as a wave shape. During formation of the first sealing layer 140a, the end face 142 of the first sealing layer may be controlled such that the end face 142 is easily terminated at the vent 124c, because the wavy vent 124c may prevent the generated solid product from entering the first cavity 122a.

In order to enable one skilled in the art to practice the invention, a method of fabricating the MEMS package of the present invention is described further below.

Fig. 4-10 are schematic cross-sectional views of a method of manufacturing a MEMS package at various stages of manufacture according to some embodiments of the invention.

Referring to fig. 4, in step 402, a cover substrate 120 is provided. The cover substrate 120 may be a semiconductor substrate or an insulating substrate, but is not limited thereto. By performing photolithography and etching processes, a plurality of grooves, such as a first groove 422a, a second groove 422b, and a third groove 422c, may be formed on the top surface of the cover substrate 120. The first and third grooves 422a, 422c are located in the first region 452 and are connected to each other, and the second groove 422b is in the second region 454 and is laterally (e.g., in the X-direction) spaced from the first and third grooves 422a, 422 c. In some embodiments, the first, second, and third grooves 422a, 422b, and 422c have a first depth D1, a second depth D2, and a third depth D3 in the Z-direction. The first depth D1 and the second depth D2 are both greater than the third depth D3. The dimensions of the first and second grooves 422a, 422b in the Y direction are greater than, for example, more than two times greater than the dimensions of the third groove 422c in the Y direction. The bonding dielectric layer 220 is formed on the top surface of the cover substrate 120 and conformally covers the sidewalls and bottom surfaces of the first to third grooves 422a, 422b, 422 c. In some embodiments, the bonding dielectric layer 220 may surround the entire cover substrate 120, which may be formed through a thermal oxidation process or a deposition process.

Referring to fig. 4, in step 404, a bonding process, such as a wafer bonding process, may be performed to bond the device substrate 210 to the cap substrate 120 by the bonding dielectric layer 220, and the bonding dielectric layer 220 may be disposed between the device substrate 210 and the cap substrate 120. By performing the bonding process, the first, second and third grooves 422a, 422b and 422c may be covered by the element substrate 210 to become the first, second and third cavities 122a, 122b and 424. By controlling the ambient pressure (e.g., chamber pressure) during the bonding process, the first, second and third cavities 122a, 122b and 424 may have a predetermined pressure, for example, for a bonding process performed in a chamber having a chamber pressure of 10 ^-5 to 5atm, the first, second and third cavities 122a, 122b and 424 may also have a pressure equal to the chamber pressure in the bonding process.

Then, a patterning process may be performed to form the protruding portions, as shown in step 404, the first protruding portion 130a and the second protruding portion 130b, which extend from the body of the device substrate 210. In some embodiments, the first and second protruding portions 130a and 130b are formed by performing photolithography and etching processes, so that the first and second protruding portions 130a and 130b may be integrally formed with the element substrate 210.

Referring to fig. 5, in step 406, a first MEMS element 214 and a second MEMS element 216 may be fabricated in an element substrate 210. The first and second MEMS elements 214, 216 may be part of an Inertial Measurement Unit (IMU) and may be formed of, but are not limited to, a movable proof mass, a movable cantilever beam, a movable cantilever ring, or a combination thereof. In some embodiments, the type of first MEMS element 214 is different from the second MEMS element 216, e.g., the first MEMS element 214 may be an accelerometer that needs to operate at a relatively high pressure, e.g., a pressure greater than or equal to 1.0 standard atmospheric pressure (atm), while the second MEMS element may be a gyroscope that needs to operate at a relatively low pressure, e.g., a pressure less than 1.0 atm. Then, a bonding material 212, such as a eutectic bonding material of Au-Ge, au-Si, al-Ge, al-Si, or a combination thereof, is formed on the protruding portions 130a, 130 b.

Fig. 6 is a schematic top view of a third cavity 424 of a different type in the first region 452 according to some embodiments of the invention. Referring to fig. 6, in the first region 452a, the third cavity 424 is straight in shape, has a circular end 426 remote from the first cavity 122a, and is covered by the cover substrate 120 a. In addition to the straight third cavity 424, the third cavity 424 may have other shapes as shown by the respective first regions 452a, 452b, 452c, 452 d.

For the third cavity 424 in the first region 452b, the third cavity 424 is not straight, but is non-linear, including a plurality of interconnected and mutually perpendicular channels. For the third cavity 424 in the first region 452c, the third cavity 424 is not a straight shape, but a nonlinear shape, such as a wave shape. For the third cavity 424 in the first region 452d, the third cavity 424 is not a straight shape, but a nonlinear shape such as a zigzag shape.

Referring to fig. 7, in step 408, a base substrate 102 is provided. In some embodiments, the base substrate 102 includes a support substrate 202 and an interconnect layer 204 disposed on the support substrate 202. In some embodiments, the support substrate 202 is a semiconductor substrate for accommodating semiconductor elements such as transistors, but is not limited thereto. In some embodiments, the support substrate 202 may be an insulating substrate without any transistors, and the interconnect layer 204 includes an inter-metal dielectric (IMD) layer and a plurality of conductive interconnect lines and vias. Conductive interconnect lines and vias have a predetermined design layout and may be electrically coupled to first and second MEMS elements 214 and 216 disposed on interconnect layer 204, and protective layer 206 may be disposed on interconnect layer 204 to protect portions of interconnect layer 204, base substrate 102 having two opposing sides, e.g., front side 102-1 and back side 102-2. In a subsequent process, the front side 102-1 may face and be bonded to the device substrate.

Referring to fig. 8, in step 410, the base substrate 102 is bonded to the device substrate 210 by the bonding material 212. By performing the bonding process, the first lower cavity 132a is formed between the device substrate 210 and the base substrate 102 in the first region 452. As such, during operation, at least a portion of the first MEMS element 214 may move, vibrate, or rotate in the space formed by the first lower cavity 132a and the first cavity 122 a. In addition, by performing the bonding process, the second lower cavity 132b is formed between the device substrate 210 and the base substrate 102 in the second region 454. As such, during operation, at least a portion of the second MEMS element 216 may move, vibrate, or rotate in the space formed by the second lower cavity 132b and the second cavity 122 b.

After the bonding process, the cover substrate 120 may be thinned to a predetermined thickness. Then, a conductive layer 222 such as a metal layer may be disposed on the top surface 120-2 of the cover substrate 120. The conductive layer 222 may be further patterned in a subsequent patterning process and electrically coupled to the first MEMS element 214, the second MEMS element 216, the interconnect layer 204, or a combination thereof. Optional conductive vias (not shown) may be formed in the cover substrate 120 and/or the element substrate 210 that are configured to transmit electrical signals to or from the first MEMS element 214 and the second MEMS element 216.

Referring to fig. 8 and 9, in step 412, the cover substrate 120 at the interface of the first region 452 and the second region 454 is removed by etching, sawing or laser cutting. In some embodiments, the conductive layer 222, the bonding dielectric layer 220, and the element substrate 210b at the interface of the first region 452 and the second region 454 may also be removed simultaneously. During this removal process, the cover substrate 120 adjacent to the end of the third recess 424 may be removed. In addition, the rounded end 426 of the third recess 424 shown in fig. 6 may be removed to obtain the vent 124 between the bonding dielectric layer 220a and the first element substrate 210a, the vent 124 including an outer opening 126 connected to the ambient environment and an inner opening 128 connected to the first cavity 122a, and the pressure of the first cavity 122a may be controlled by flowing the ambient air into or out of the first cavity 122a through the vent 124, such that the pressure of the first cavity 122a may be equal to the ambient pressure.

Referring to fig. 10, in step 414, a sealing layer 140 is formed to seal the vent 124. In some embodiments, the sealing layer 140 may be a blanket layer covering all the components or members on the base substrate 102, and thus, the sealing layer 140 may cover the sidewalls of the first and second cover substrates 120a and 120b, and the sidewalls of the first and second element substrates 210a and 210 b. During formation of the sealing layer 140, the pressure of the first cavity 122a is affected by the ambient pressure (e.g., chamber pressure) within the deposition chamber. In some embodiments, the pressure of the first cavity 122a may be substantially equal to the chamber pressure of the deposition chamber, however, once the vent 124 is sealed by the sealing layer 140, the pressure of the first cavity 122a will no longer be affected by the chamber pressure of the deposition chamber.

Subsequently, after step 414, other processes, such as an etching process, may be performed to obtain the MEMS package 100 as shown in fig. 2. By performing the etching process, the conductive layers 222a and 222b may be exposed, and the first and second sealing layers 140a and 140b may be formed on the sidewalls of the first and second cover substrates 120a and 120b, and the sidewalls of the first and second element substrates 210a and 210b, respectively. In some embodiments, the first sealing layer 140a and the second sealing layer 140b are self-aligned structures obtained without performing a photolithography process.

The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several equivalent substitutions and obvious modifications can be made without departing from the spirit of the invention, and the same should be considered to be within the scope of the invention.

Claims (20)

1. A microelectromechanical system package comprising a first MEMS package and a second MEMS package, the second MEMS package being laterally spaced apart from the first MEMS package;

The first MEMS package includes:

a first element substrate including a first MEMS element;

A first cover substrate bonded to the first element substrate, wherein the first cover substrate encloses a first cavity and a vent hole, the vent hole being connected to the first cavity; and

A first sealing layer filled in at least a portion of the vent hole, wherein the first sealing layer is disposed between the first element substrate and the first cover substrate;

the second MEMS package includes:

A second element substrate comprising a second MEMS element; and

A second cover substrate bonded to the second element substrate, wherein the second cover substrate encloses the second cavity;

Wherein the first cavity has a first pressure and the second cavity has a second pressure different from the first pressure.

2. The microelectromechanical system package of claim 1, wherein the first MEMS element comprises an accelerometer and the second MEMS element comprises a gyroscope, the first pressure being greater than the second pressure.

3. The microelectromechanical system package of claim 1, wherein a height of the first cavity is greater than a height of the vent hole.

4. The mems package of claim 1, wherein the vent hole exhibits a non-linear shape or a straight line shape when viewed from a top view.

5. The mems package of claim 4, wherein the nonlinear shape comprises a wavy shape or a saw tooth shape.

6. The mems package of claim 1 wherein the first sealing layer includes an end surface located in the vent hole, the end surface of the first sealing layer being spaced apart from the first cavity.

7. The microelectromechanical system package of claim 1, wherein the first sealing layer also covers sidewalls of the first element substrate and sidewalls of the first cover substrate.

8. The microelectromechanical system package of claim 1, wherein the first MEMS package further comprises a bonding dielectric layer disposed between the first element substrate and the first cover substrate, the bonding dielectric layer surrounding the first cavity and the vent.

9. The mems package of claim 1 wherein the first element substrate further includes a downwardly extending ledge, a portion of the ledge overlapping the first cavity and being laterally spaced from the vent.

10. The MEMS package of claim 9 wherein the first MEMS package further includes a first lower cavity surrounded by the protruding portion.

11. The microelectromechanical system package of claim 1, wherein the first MEMS package further comprises a conductive layer disposed on a top surface of the first cover substrate.

12. The mems package of claim 11, wherein the conductive layer is electrically coupled to an interconnect layer disposed under the first element substrate.

13. The mems package of claim 1, further comprising an interconnect layer disposed under the first and second element substrates, the interconnect layer bonded to the first and second element substrates.

14. The microelectromechanical system package of claim 13, wherein the interconnect layer is electrically coupled to the first MEMS element and the second MEMS element.

15. The mems package of claim 13 wherein the first sealing layer further fills a gap between the interconnect layer and the first element substrate.

16. The MEMS package of claim 1, wherein the second MEMS package further comprises a second sealing layer covering sidewalls of the second element substrate, and wherein the second sealing layer has the same composition as the first sealing layer.

17. A method of manufacturing a microelectromechanical systems package, comprising:

Providing a cover substrate comprising a first groove, a second groove and a third groove, wherein the first groove is connected to the third groove, and the first groove and the third groove are transversely separated from the second groove, and the depth of the first groove and the depth of the second groove are larger than the depth of the third groove;

Covering the first, second and third grooves with the cover substrate under an ambient pressure to form a first, second and third cavity;

Removing the cover substrate adjacent to one end of the third groove to form a vent hole;

flowing gas through the vent at another ambient pressure different from the ambient pressure; and

After the gas flows through the vent holes, a sealing layer is filled into the vent holes.

18. The method of manufacturing a mems package of claim 17, wherein the first cavity, the second cavity, and the third cavity have a pressure equal to the ambient pressure prior to forming the vent.

19. The method of manufacturing a mems package according to claim 17, wherein the first cavity has a pressure after the sealing layer is filled into the vent hole, the pressure being equal to the other ambient pressure.

20. The method of claim 19, wherein the second cavity has another pressure after the sealing layer is filled into the vent hole, the another pressure being equal to the ambient pressure.