TWI850094B - Micro-electro-mechanical system package and fabrication method thereof - Google Patents

Abstract

A micro-electro-mechanical system (MEMS) package includes a wafer with an interconnect layer disposed thereon. A first device substrate including a first MEMS device and a second device substrate including a second MEMS device are laterally spaced apart from each other and disposed on the wafer. A first and a second bond seal rings are disposed below the first and the second device substrates, respectively, and both bonded to the interconnect layer. A first handle substrate includes a first cavity having a first pressure, and is bonded to the first device substrate. A second handle substrates includes a second cavity having a second pressure different from the first pressure, and is bonded to the second device substrate.

Description

Micro-electromechanical package and its manufacturing method

The present disclosure relates to a micro-electromechanical system (MEMS) package, and in particular to a micro-electromechanical system package including MEMS components with different pressures and a manufacturing method thereof.

Micro-electromechanical (MEMS) devices are miniature components that integrate mechanical and electrical components to sense physical quantities and/or interact with the surrounding environment. MEMS devices such as accelerometers, gyroscopes, pressure sensors, and microphones have been widely used in many modern electronic products. For example, inertial measurement units (IMUs) composed of accelerometers and/or gyroscopes are commonly found in tablets, cars, or smartphones. For some applications, it is necessary to integrate various MEMS components into a MEMS package. However, for MEMS components that require different pressures, these MEMS components need to be packaged separately under different environmental pressures and then integrated into a MEMS package. Therefore, the packaging process of traditional MEMS packaging is complicated, and traditional MEMS packaging also requires a larger footprint.

In view of this, some embodiments of the present disclosure provide a microelectromechanical (MEMS) package and a manufacturing method thereof to overcome the aforementioned shortcomings of conventional MEMS packages. The MEMS package disclosed herein includes a hole in a bonding seal ring to achieve pressure adjustment of the cavity of the MEMS element after bonding. In addition, an anti-adhesion coating can also be formed on the MEMS element during the pressure adjustment process step. Therefore, compared to conventional MEMS packages, the packaging process of the MEMS package disclosed herein including multiple MEMS elements with different cavity pressures can be simplified, and the MEMS package occupies a smaller area.

According to an embodiment of the present disclosure, a microelectromechanical (MEMS) package is provided, including a wafer, an interconnection layer, a first component substrate, a second component substrate, a first bonding sealing ring, a second bonding sealing ring, a first supporting substrate, a second supporting substrate, holes, and a dielectric film. The interconnection layer is arranged on the wafer, the first component substrate includes a first MEMS element and is arranged on the wafer, the second component substrate includes a second MEMS element and is arranged on the wafer, and the second component substrate is laterally separated from the first component substrate. The first bonding sealing ring is arranged below the first component substrate and bonded to the interconnection layer, and the second bonding sealing ring is arranged below the second component substrate and bonded to the interconnection layer. The first supporting substrate includes a first cavity and is bonded to the first component substrate, and the second supporting substrate includes a second cavity and is bonded to the second component substrate. The hole is arranged in the second bonding sealing ring, the dielectric film is arranged on the interconnection layer, and is adjacent to the first bonding sealing ring and the second bonding sealing ring. The first cavity has a first pressure, and the second cavity has a second pressure, and the second pressure is different from the first pressure.

According to an embodiment of the present disclosure, a method for manufacturing a micro-electromechanical system package is provided, comprising the following steps: providing a support wafer, wherein a first cavity and a second cavity are formed therein; providing a device wafer, wherein a first MEMS device and a second MEMS device are formed therein and are laterally spaced from each other; forming a first bonding seal ring and a second bonding seal ring, respectively, below the first MEMS device and the second MEMS device; forming a hole in the second bonding seal ring; forming two pre-cut lines in the device wafer, and the pre-cut lines are located between ... between a MEMS element and a second MEMS element; bonding a support wafer to a component wafer, wherein a first cavity is located directly above the first MEMS element and a second cavity is located directly above the second MEMS element; providing a wafer and forming an interconnect layer on the wafer; bonding the component wafer to the interconnect layer on the wafer under a first pressure; removing a portion of the support wafer and a portion of the component wafer between two pre-cut lines to expose a hole in a second bonding sealing ring to an ambient pressure; and forming a dielectric film on the interconnect layer.

In order to make the features of this disclosure clear and easy to understand, the following is a detailed description of the embodiments with the help of the attached drawings.

100:Micro-electromechanical packaging

100A: First MEMS area

100B: Second MEMS area

SL: Cutting Road

110: Support wafer

110A: The first supporting substrate

110B: Second supporting substrate

110F, 110K, 110T: Surface

112: First cavity

114: Second cavity

116: Bonding layer

116A: First bonding layer

116B: Second bonding layer

118, 118A, 118B: Conductive layer

120: Component wafer

120A: First component substrate

120B: Second component substrate

120P: Part of the component wafer

121: Support bump

122: First MEMS element

123, 127: Groove

124: Second MEMS element

125A: First key sealing ring

125B: Second key sealing ring

126: Bonding materials

130: Wafer

132: Interconnection layer

134: Protective layer

140: Ventilation holes/holes

142: Hole

145: Anti-adhesion coating

150: Step structure

151, 152, 153: Pre-cut lines

152P: protruding part

154:Joint pad

160: Dielectric film

161: Dielectric material layer

170: Sealing layer

S101, S103, S105, S107, S201, S202, S203, S205, S207: Steps

In order to make the following easier to understand, the drawings and their detailed text descriptions can be referred to simultaneously when reading this disclosure. Through the specific embodiments in this article and reference to the corresponding drawings, the specific embodiments of this disclosure are explained in detail, and the working principles of the specific embodiments of this disclosure are explained. In addition, for the sake of clarity, the features in the drawings may not be drawn according to the actual scale, so the size of some features in some drawings may be deliberately enlarged or reduced.

Figure 1 is a schematic top view of a micro-electromechanical system (MEMS) package according to an embodiment of the present disclosure.

Figure 2 is a cross-sectional schematic diagram of a MEMS package according to an embodiment of the present disclosure.

Figure 3 is a schematic top view of a MEMS package according to another embodiment of the present disclosure.

Figure 4 is a cross-sectional schematic diagram of a MEMS package according to another embodiment of the present disclosure.

Figures 5, 6 and 7 are cross-sectional schematic diagrams of some intermediate stages of a method for manufacturing a MEMS package according to an embodiment of the present disclosure.

Figures 8, 9 and 10 are cross-sectional schematic diagrams of some intermediate stages of a method for manufacturing a MEMS package according to another embodiment of the present disclosure.

The present disclosure provides several different embodiments that can be used to implement different features of the present disclosure. For the purpose of simplifying the description, the present disclosure also describes examples of specific components and arrangements. The purpose of providing these embodiments is only for illustration and not for limitation. For example, the description below of "a first feature is formed on or above a second feature" may refer to "the first feature is in direct contact with the second feature" or "there are other features between the first feature and the second feature", so that the first feature and the second feature are not in direct contact. In addition, various embodiments in the present disclosure may use repeated reference symbols and/or text annotations. These repeated reference symbols and annotations are used to make the description more concise and clear, rather than to indicate the relationship between different embodiments and/or configurations.

In addition, for the spatially related descriptive terms mentioned in this disclosure, such as "under", "low", "down", "above", "above", "up", "top", "bottom" and similar terms, for the convenience of description, their usage is to describe the relative relationship between one element or feature and another (or multiple) elements or features in the drawings. In addition to the orientation shown in the drawings, these spatially related terms are also used to describe the possible orientations of the MEMS package during use and operation. As the orientation of the MEMS package is different (rotated 90 degrees or other orientations), the spatially related descriptions used to describe its orientation should also be interpreted in a similar manner.

Although the present disclosure uses the terms first, second, third, etc. to describe various elements, components, regions, layers, and/or blocks, it should be understood that these elements, components, regions, layers, and/or blocks should not be limited by these terms. These terms are only used to distinguish a certain element, component, region, layer, and/or block from another element, component, region, layer, and/or block, and they do not imply or represent any previous sequence of the element, nor do they represent the arrangement order of a certain element and another element, or the order of the manufacturing method. Therefore, without departing from the scope of the specific embodiments of the present disclosure, the first element, component, region, layer, or block discussed below can also be referred to as the second element, component, region, layer, or block.

The terms "about" or "substantially" mentioned in this disclosure generally mean within 20% of a given value or range, preferably within 10%, and more preferably within 5%, or within 3%, or within 2%, or within 1%, or within 0.5%. It should be noted that the quantities provided in the specification are approximate quantities, that is, in the absence of specific description of "about" or "substantially", the meaning of "about" or "substantially" can still be implied.

The terms "coupling", "coupling", and "electrical connection" mentioned in this disclosure include any direct and indirect electrical connection means. For example, if the text describes that a first component is coupled to a second component, it means that the first component can be directly electrically connected to the second component, or indirectly electrically connected to the second component through other devices or connection means.

Although the invention disclosed herein is described below by means of specific embodiments, the invention principles disclosed herein can also be applied to other embodiments. In addition, in order not to obscure the spirit of the invention, certain details will be omitted, and these omitted details belong to the knowledge scope of those with ordinary knowledge in the relevant technical field.

The present disclosure relates to a microelectromechanical (MEMS) package and a method of making the same, wherein the MEMS package includes a first MEMS component packaged under a first pressure and a second MEMS component packaged under a second pressure, the second pressure being different from the first pressure. In some embodiments, the MEMS package may include an inertial measurement unit (IMU), which may include an accelerometer and a gyroscope, and other MEMS components that require different pressures. In some embodiments, the first MEMS component may be a gyroscope that requires a first pressure of high vacuum, and the second MEMS component may be an accelerometer that requires a second pressure of low vacuum. The first bonding sealing ring and the second bonding sealing ring are respectively arranged corresponding to the first MEMS element and the second MEMS element, and a hole is arranged in the second bonding sealing ring to form a vent hole, thereby achieving pressure adjustment of the second cavity of the second MEMS element after bonding. In addition, during the process step of pressure adjustment after bonding, an anti-stiction coating layer can also be formed on the second MEMS element through the vent hole. Therefore, the packaging process of the MEMS package containing various MEMS elements with different cavity pressures is simplified, and the footprint of the MEMS package is smaller than that of the traditional MEMS package.

FIG. 1 is a schematic top view of a micro-electromechanical system package 100 according to an embodiment of the present disclosure. The micro-electromechanical system package 100 includes various MEMS components separated from each other. For example, a first MEMS component 122 is located in a first MEMS region 100A, and a second MEMS component 124 is located in a second MEMS region 100B. The first MEMS region 100A and the second MEMS region 100B are separated by a scribe line SL. Two pre-cut lines 151 and 152 are formed in the scribe line SL and are located between the first MEMS component 122 and the second MEMS component 124. In addition, a plurality of bond pads 154 are provided in the scribe line SL and are located between the two pre-cut lines 151 and 152. Another pre-cut line 153 is also formed in the scribe line SL. The first MEMS element 122 and the second MEMS element 124 require different vacuum levels for operation, and the first MEMS element 122 and the second MEMS element 124 have different MEMS structures. The first MEMS element 122 and the second MEMS element 124 may include various component features, such as standoff bumps 121, grooves 127, and proof mass (not shown), and the layout of the standoff bumps 121, grooves 127, and other component features of the first MEMS element 122 is different from the layout of those component features of the second MEMS element 124. In some embodiments, the first MEMS element 122 is, for example, a gyroscope that requires high vacuum, and the second MEMS element 124 is, for example, an accelerometer that requires low vacuum or atmospheric pressure. In addition, the second MEMS element 124 may require an anti-adhesion coating, while the first MEMS element 122 may not require an anti-adhesion coating, but is not limited thereto.

In addition, the micro-electromechanical package 100 includes a first cavity 112 located directly above the first MEMS element 122, and a second cavity 114 located directly above the second MEMS element 124. The first cavity 112 has a first pressure, and the second cavity 114 has a second pressure. Since the first MEMS element 122 and the second MEMS element 124 require different cavity pressures, the second pressure is different from the first pressure. From a top view, the first MEMS element 122 and the second MEMS element 124 may both include a groove 123 located outside or inside their cavity range. In addition, the micro-electromechanical package 100 includes a first bonding seal ring 125A disposed corresponding to the first MEMS element 122, and a second bonding seal ring 125B disposed corresponding to the second MEMS element 124. In some embodiments, a hole 140 is provided in the second keyed sealing ring 125B to form a vent hole for adjusting the pressure in the second cavity 114. The hole 140 is formed laterally through the second keyed sealing ring 125B (e.g., along the Y-axis direction) and is connected to the second cavity 114. In other embodiments, a plurality of holes 140 may be provided in the second keyed sealing ring 125B to form a plurality of vent holes for adjusting the pressure in the second cavity 114, each hole 140 is formed laterally through the second keyed sealing ring 125B (e.g., along the X-axis or Y-axis direction), and all holes 140 are connected to the second cavity 114. In some embodiments, the width of each hole 140 in the X-axis or Y-axis direction may be between about 1 micrometer (μm) and about 100 μm, and the length of each hole 140 in the Y-axis or X-axis direction is substantially the same as the width of the second keying seal ring 125B.

FIG. 2 is a cross-sectional schematic diagram of a MEMS package 100 according to an embodiment of the present disclosure, which is drawn along the section line A-A' in FIG. 1. In order to make the diagram concise and easy to understand, the cross-sectional details of the first MEMS element 122 and the second MEMS element 124 in FIG. 2 are simplified, wherein the number of trenches 127 and the component size between the trenches 127 do not completely correspond to FIG. 1, and those simplified details are understandable to those with ordinary knowledge in the relevant technical field. The MEMS package 100 includes a wafer 130 and an interconnect layer 132 formed on the wafer 130. The wafer 130 may include a plurality of complementary metal oxide semiconductors (CMOS) or other devices formed therein, and the interconnect layer 132 includes a plurality of metal layers, a plurality of inter-metal dielectric (IMD) layers, and a plurality of vias in the IMD layer for connecting two metal layers. A bond pad 154 is disposed on the top metal layer of the interconnect layer 132, and a protective layer 134 is also disposed on the top metal layer of the interconnect layer 132 and has a plurality of openings to expose the bond pads 154 respectively. In addition, the micro-electromechanical package 100 includes a first element substrate 120A and a second element substrate 120B. The first element substrate 120A includes a first MEMS element 122 and is disposed on a wafer 130. The second element substrate 120B includes a second MEMS element 124 and is also disposed on the wafer 130. The second element substrate 120B is laterally separated from the first element substrate 120A. In order to make the figure simple and easy to understand, the MEMS structure of the first MEMS element 122 and the second MEMS element 124 is simplified in FIG. 2. In addition, a first bonding sealing ring 125A is disposed below the first element substrate 120A and is bonded to the interconnection layer 132 via a bonding material 126. A second bonding sealing ring 125B is disposed below the second element substrate 120B and is also bonded to the interconnection layer 132 via a bonding material 126. In some embodiments, the first bonding seal ring 125A and the first element substrate 120A can be an integrally formed structure and have the same composition, such as silicon. The second bonding seal ring 125B and the second element substrate 120B can also be an integrally formed structure and have the same composition, such as silicon. The bonding material 126 is used to produce eutectic bonding with the top metal layer of the interconnect layer 132, such as germanium (Ge).

In addition, the micro-electromechanical package 100 includes a first supporting substrate 110A, which is bonded to a first element substrate 120A via a first bonding layer 116A, and a second supporting substrate 110B, which is bonded to a second element substrate 120B via a second bonding layer 116B. The first supporting substrate 110A includes a first cavity 112 formed therein, and the first cavity 112 is disposed directly above a first MEMS element 122. The second supporting substrate 110B includes a second cavity 114 formed therein, and the second cavity 114 is disposed directly above a second MEMS element 124. The first bonding layer 116A is disposed between the first element substrate 120A and the first supporting substrate 110A. In some embodiments, the first bonding layer 116A may further extend into the first cavity 112 to be conformally disposed on the sidewalls and bottom surface of the first cavity 112. The second bonding layer 116B is disposed between the second element substrate 120B and the second supporting substrate 110B, and the second bonding layer 116B may also extend into the second cavity 114 to be conformally disposed on the sidewalls and bottom surface of the second cavity 114. In addition, a conductive layer 118A may be disposed on the top surface of the first supporting substrate 110A, and a conductive layer 118B may be disposed on the top surface of the second supporting substrate 110B. The conductive layer 118A may be a patterned conductive layer electrically coupled to the first MEMS element 122 and/or the interconnection layer 132, and the conductive layer 118B may be a patterned conductive layer electrically coupled to the second MEMS element 124 and/or the interconnection layer 132.

In some embodiments, as shown in FIG. 2 , the hole 140 passes through the second bonding seal ring 125B laterally along the X-axis direction and is connected to the second cavity 114 through the groove of the second MEMS element 124. Therefore, after the second element substrate 120B is bonded to the interconnect layer 132 on the wafer 130, the hole 140 can be used as a vent to adjust the pressure in the second cavity 114 to achieve the pressure required by the second MEMS element 124. In some embodiments, in the Z-axis direction, the height of the vent/hole 140 can be the same as or slightly less than the thickness of the second bonding seal ring 125B, and the height of the vent/hole 140 can be, for example, about 1μm to about 2μm.

In some embodiments, the first cavity 112 has a first pressure P1, and the second cavity 114 can adjust the pressure in the second cavity 114 through the vent hole/hole 140 in the second bonding seal ring 125B, so that the second cavity 114 has a second pressure P2 different from the first pressure P1. During the process step of bonding the first component substrate 120A to the interconnect layer 132 on the wafer 130, the first pressure P1 in the first cavity 112 can be controlled and determined. After the second component substrate 120B is bonded to the interconnect layer 132 on the wafer 130, the pressure in the second cavity 114 can be adjusted to a desired vacuum level through the vent hole/hole 140 to obtain the second pressure P2 in the second cavity 114. Furthermore, during the process step of adjusting the pressure in the second cavity 114, the anti-adhesion coating 145 may be formed sequentially on the second element substrate 120B through the vent/hole 140 to wrap the second MEMS element 124. After the second pressure P2 in the second cavity 114 is adjusted to a desired vacuum level and the anti-adhesion coating 145 is formed on the second MEMS element 124, a dielectric film 160 may be formed on the interconnect layer 132, wherein a portion of the vent/hole 140 is filled with the dielectric film 160 to reseal the vent/hole 140. In this embodiment, the top surface of the interconnect layer 132 may provide a step structure for depositing the dielectric film 160 to reseal the vent/hole 140. The dielectric film 160 may be formed on the protective layer 134 and adjacent to the first bonding seal ring 125A and the second bonding seal ring 125B. Since the height of the vent/hole 140 is very small, for example, about 1 μm to about 2 μm, the vent/hole 140 may be easily resealed by depositing the dielectric film 160 on the interconnect layer 132. In addition, in this embodiment, a portion of the bonding material 126 may be formed on the back side of the second element substrate 120B in the region of the hole 140, and the dielectric film 160 is adjacent to this portion of the bonding material 126.

FIG. 3 is a schematic top view of a MEMS package 100 according to another embodiment of the present disclosure. In the MEMS package 100 of FIG. 3 , a hole 142 is disposed in the second keying seal ring 125B and vertically passes through the second keying seal ring 125B along the Z-axis direction. From the top view, the hole 142 is surrounded by the second keying seal ring 125B, and the hole 142 does not pass through the second keying seal ring 125B laterally in the Y-axis or X-axis direction. In addition, in this embodiment, the pre-cut line 152 adjacent to the second bonding sealing ring 125B has a protrusion (platform structure) 152P corresponding to the position of the hole 142, and the protrusion 152P protrudes outward away from the hole 142. The protrusion 152P can provide a step structure on the outside of the vent formed by the hole 142. In some embodiments, multiple holes 142 can be formed in the second bonding sealing ring 125B, and the pre-cut line 152 has multiple protrusions 152P corresponding to these holes 142. The details of other component features of the MEMS package 100 in FIG. 3 can refer to the relevant description of the MEMS package 100 in FIG. 1, which will not be repeated here.

FIG. 4 is a cross-sectional schematic diagram of a MEMS package 100 according to another embodiment of the present disclosure, which is drawn along the cross-sectional line B-B' in FIG. 3. In order to make the diagram concise and easy to understand, the cross-sectional details of the first MEMS element 122 and the second MEMS element 124 in FIG. 4 are simplified, wherein the number of grooves 127 and the component size between the grooves 127 do not completely correspond to FIG. 3, and those simplified details are understandable to those with ordinary knowledge in the relevant technical field. The MEMS package 100 includes a hole 142 disposed in the second keying seal ring 125B, and the hole 142 vertically passes through the second keying seal ring 125B in the Z-axis direction, and further extends to pass through the second element substrate 120B. In this embodiment, a portion of the second bonding layer 116B between the second element substrate 120B and the second supporting substrate 110B can be removed by etching through the hole 142 to form a vent hole 140 in the second bonding layer 116B. As shown in FIG. 4, in some embodiments, the vent hole 140 extends laterally along the X-axis direction between the second element substrate 120B and the second supporting substrate 110B. In addition, the vent hole 140 is connected to the second cavity 114 and the hole 142, and the second pressure P2 in the second cavity 114 can be adjusted to the desired vacuum degree through the vent hole 140, so that the second pressure P2 in the second cavity 114 is different from the first pressure P1 in the first cavity 112.

In addition, in this embodiment, as shown in FIG. 3 , the pre-cut line 152 adjacent to the second bonding seal ring 125B has a protruding portion 152P. After the cutting process is performed on the cutting line SL, as shown in FIG. 4 , the second element substrate 120B and the second supporting substrate 110B form a step structure 150 adjacent to the hole 142, and the vent hole 140 formed through the hole 142 is located in the step structure 150. In addition, during the process step of adjusting the pressure in the second cavity 114, the anti-adhesion coating 145 can be disposed on the second element substrate 120B in a directional manner through the vent hole 140 to wrap the second MEMS element 124. When the second pressure P2 in the second cavity 114 is adjusted to the desired vacuum degree, and after the anti-adhesion coating 145 is formed on the second MEMS element 124 through the vent 140, the sealing layer 170 is deposited on the platform of the step structure 150 so that a portion of the vent 140 is filled with the sealing layer 170 to reseal the vent 140. In addition, a dielectric film 160 may be formed on the protective layer 134 of the interconnect layer 132, and the dielectric film 160 is located adjacent to the first bonding sealing ring 125A and the second bonding sealing ring 125B. In some embodiments, the sealing layer 170 and the dielectric film 160 may be formed by the same deposition process and have the same composition, such as silicon oxide.

In some embodiments, as shown in FIG. 4 , the first bonding layer 116A is disposed between the first element substrate 120A and the first supporting substrate 110A, and does not extend to the sidewalls and the bottom surface of the first cavity 112. The second bonding layer 116B is disposed between the second element substrate 120B and the second supporting substrate 110B, and does not extend to the sidewalls and the bottom surface of the second cavity 114, and a portion of the second bonding layer 116B corresponding to the hole 142 may be removed to form the vent 140. In some embodiments, in the Z-axis direction, the height of the vent 140 may be the same as or slightly less than the thickness of the second bonding layer 116B, for example, the height of the vent 140 may be about 1000 angstroms (Å) to about 2000 Å. In some embodiments, the width of the vent hole 140 in the Y-axis direction may be in the range of about 1 μm to about 100 μm, and the length of the vent hole 140 in the X-axis direction may be the same as the width of the second bonding layer 116B. The details of other component features of the MEMS package 100 in FIG. 4 can refer to the relevant description of the MEMS package 100 in FIG. 2 above, which will not be repeated here.

FIG. 5, FIG. 6 and FIG. 7 are cross-sectional schematic diagrams of some intermediate stages of a method for manufacturing a micro-electromechanical system package according to an embodiment of the present disclosure. Referring to FIG. 5, in step S101, a handle wafer 110, such as a silicon wafer, is first provided, and an etching process is performed on a surface 110F of the handle wafer 110 to form a first cavity 112 and a second cavity 114. Then, a bonding layer 116 is sequentially deposited on the handle wafer 110 and in the first cavity 112 and the second cavity 114 to wrap the handle wafer 110. The bonding layer 116 is composed of, for example, silicon dioxide, and the bonding layer 116 can be formed by thermal oxidation or a deposition process. In addition, a device wafer 120, such as a silicon wafer, is provided and bonded to the surface 110F of the support wafer 110 to cover the first cavity 112 and the second cavity 114. Thereafter, the device wafer 120 is patterned by photolithography and etching processes to form a first MEMS element 122 and a second MEMS element 124 that are laterally separated from each other. As shown in FIG. 5 , the device wafer 120 includes a first device substrate 120A having a first MEMS element 122, a second device substrate 120B having a second MEMS element 124, and a portion 120P of the device wafer 120 located between the first device substrate 120A and the second device substrate 120B. A pre-cut line 151 is formed in the device wafer 120 and is located between the first device substrate 120A and a portion 120P of the device wafer 120. Another pre-cut line 152 is formed in the device wafer 120 and is located between the second device substrate 120B and a portion 120P of the device wafer 120. The two pre-cut lines 151 and 152 are formed between the first MEMS device 122 and the second MEMS device 124. The pre-cut lines 151 and 152 and the grooves of the first MEMS device 122 and the second MEMS device 124 can be formed simultaneously by the same etching process, such as a deep reactive-ion etching (DRIE) process.

In addition, a first bonding sealing ring 125A and a second bonding sealing ring 125B are formed, corresponding to the first MEMS element 122 and the second MEMS element 124, respectively, wherein the first bonding sealing ring 125A and the first element substrate 120A can be an integrally formed structure formed by the element wafer 120, and the second bonding sealing ring 125B and the second element substrate 120B can also be an integrally formed structure formed by the element wafer 120. The first bonding sealing ring 125A and the second bonding sealing ring 125B can be formed by patterning the element wafer 120. In this embodiment, a hole 140 as shown in FIG. 1 can be formed in the second bonding sealing ring 125B by an etching process, and the hole 140 laterally passes through the second bonding sealing ring 125B. Afterwards, a bonding material 126, such as germanium (Ge), is formed on the first bonding sealing ring 125A and the second bonding sealing ring 125B, wherein the bonding material 126 is formed on the second component substrate 120B in the region of the hole 140.

Still referring to FIG. 5 , in step S103, the bonded support wafer 110 and the device wafer 120 are turned upside down, wherein the first cavity 112 is located directly above the first MEMS element 122, and the second cavity 114 is located directly above the second MEMS element 124. Afterwards, a wafer 130 is provided, such as a CMOS wafer having an interconnection layer 132 formed thereon. Then, under a first pressure P1, the device wafer 120 is bonded to the interconnection layer 132 on the wafer 130 through a bonding material 126. In step S103, both the first cavity 112 and the second cavity 114 have the first pressure P1. In addition, a grinding or etching process is performed on the other surface 110K of the support wafer 110 to thin the support wafer 110. Then, a conductive layer 118, such as an aluminum (Al) layer, is deposited on the top surface 110T of the thinned support wafer 110.

Next, referring to FIG. 6 , in step S105, a portion of the support wafer 110 and a portion 120P of the device wafer 120 located between the two pre-cut lines 151 and 152 on the scribe line SL are removed by a dicing process, so that the hole 140 is exposed to the ambient pressure, and the bonding pad 154 on the scribe line SL is also exposed by the dicing process. In step S105, the first cavity 112 directly above the first MEMS element 122 still maintains the first pressure P1 of step S103. In addition, the hole 140 in the second bonding seal ring 125B is exposed and used as a vent to adjust the pressure in the second cavity 114, so that the pressure in the second cavity 114 can be adjusted to a second pressure P2 different from the first pressure P1. Furthermore, in some embodiments, during the process step of adjusting the pressure in the second cavity 114, the anti-adhesion coating 145 can be sequentially deposited on the second device substrate 120B through the vent/hole 140 to wrap the second MEMS device 124. In some embodiments, the anti-adhesion coating 145 can be a self-assembled monolayer (SAM) coating formed by a vapor deposition process. The composition of the anti-adhesion coating 145 can be an organic material, such as 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS), octadecyltrichlorosilane (OTS) or dichlorodimethylsilane (DDMS), but is not limited thereto.

Thereafter, referring to FIG. 7 , in step S107 , a dielectric material layer 161 is deposited on the interconnect layer 132 by a blanket deposition process, such as a chemical vapor deposition (CVD), a physical vapor deposition (PVD) or an atomic layer deposition (ALD) process, to reseal the vent/hole 140 under a second pressure P2. In addition, the dielectric material layer 161 is also deposited on the conductive layers 118A and 118B, and the composition of the dielectric material layer 161 is, for example, silicon oxide. Afterwards, the portions of the dielectric material layer 161 located on the conductive layers 118A and 118B are removed by an etching process to expose the conductive layers 118A and 118B. In addition, another portion of the dielectric material layer 161 on the interconnect layer 132 may also be removed by this etching process to form a dielectric film 160 and expose the bonding pad 154 located on the scribe line SL. In addition, a portion of the vent/hole 140 may be filled with the dielectric film 160 to complete the MEMS package 100 of FIG. 2.

FIG. 8, FIG. 9 and FIG. 10 are cross-sectional schematic diagrams of some intermediate stages of a manufacturing method of a micro-electromechanical system package 100 according to another embodiment of the present disclosure. Referring to FIG. 8, in step S201, a support wafer 110 is first provided, and a first cavity 112 and a second cavity 114 are formed in the support wafer 110. Then, a bonding layer 116 is sequentially deposited on the support wafer 110 and in the first cavity 112 and the second cavity 114 to wrap the support wafer 110. Thereafter, a device wafer 120 is provided, and the device wafer 120 is bonded to the support wafer 110 to cover the first cavity 112 and the second cavity 114. As shown in FIG. 8 , the device wafer 120 includes a first device substrate 120A having a first MEMS device 122, a second device substrate 120B having a second MEMS device 122, a first bonding sealing ring 125A corresponding to the first MEMS device 122, a second bonding sealing ring 125B corresponding to the second MEMS device 124, and a portion 120P of the device wafer 120 located between two pre-cut lines 151 and 152. In addition, a bonding material 126 is formed on the first bonding sealing ring 125A and the second bonding sealing ring 125B.

In this embodiment, in step S201, a hole 142 as shown in FIG. 3 is formed, which vertically passes through the bonding material 126 and the second bonding sealing ring 125B, and further extends to vertically pass through the second element substrate 120B, thereby exposing a portion of the bonding layer 116. In addition, the pre-cut lines 151 and 152, the trenches of the first MEMS element 122 and the second MEMS element 124, and the hole 142 can be formed simultaneously by the same etching process, such as a deep reactive ion etching (DRIE) process. For other details of step S201, please refer to the description of step S101 in FIG. 5 above, which will not be repeated here.

Still referring to FIG. 8, in step S202, by using a vapor hydrofluoric acid (VHF) etching process, through the trenches of the first MEMS element 122 and the second MEMS element 124 and the pre-cut lines 151 and 152, some portions of the bonding layer 116 in the first cavity 112 and the second cavity 114 and between the element wafer 120 and the support wafer 110 are removed. In addition, a portion of the bonding layer 116 between the second element substrate 120B and the support wafer 110 can also be removed through the hole 142 by using this VHF etching process to form a vent 140, which is connected to the second cavity 114 and the hole 142.

Next, referring to FIG. 9, in step S203, the bonded support wafer 110 and the component wafer 120 are turned upside down, wherein the first cavity 112 is located directly above the first MEMS component 122, and the second cavity 114 is located directly above the second MEMS component 124. Then, a wafer 130 is provided, on which an interconnection layer 132 is formed, and the component wafer 120 is bonded to the interconnection layer 132 on the wafer 130 through the bonding material 126 under a first pressure P1. Thereafter, a vent hole 140 is formed in the second bonding layer 116B, and the vent hole 140 can be used to adjust the pressure in the second cavity 114 in the subsequent process. For other details of step S203, please refer to the description of step S103 in Figure 5 above, which will not be repeated here.

Then, referring to FIG. 10, in step S205, a portion of the support wafer 110 and a portion 120P of the device wafer 120 located between the two pre-cut lines 151 and 152 on the scribe line SL are removed by a dicing process, so that the vent hole 140 is exposed to the ambient pressure, and the hole 142 in both the second bonding seal ring 125B and the second device substrate 120B and the second cavity 114 are also exposed to the ambient pressure. In addition, in step S205, the first cavity 112 directly above the first MEMS device 122 is still maintained at the first pressure P1 of step S203. In this embodiment, the vent hole 140 can be used to adjust the pressure in the second cavity 114 to the required vacuum level, so that the second cavity 114 has a second pressure P2, which is different from the first pressure P1 in the first cavity 112. In addition, in some embodiments, during step S205, the anti-adhesion coating 145 can be deposited on the second element substrate 120B through the vent hole 140 to wrap the second MEMS element 124. For other details of step S205, please refer to the description of step S105 in Figure 6 above, which will not be repeated here.

In addition, in this embodiment, as shown in FIG. 3, since the pre-cut line 152 has a protruding portion 152P corresponding to the position of the hole 142, after the cutting process in step S205, the second supporting substrate 110B and the second element substrate 120B can form a step structure 150 as shown in the cross-sectional schematic diagram of FIG. 10, and the vent hole 140 is located in the step structure 150.

Next, still referring to FIG. 10 , in step S207 , a dielectric material layer 161 is deposited on the platform of the terrace structure 150 to reseal the vent hole 140 under the second pressure P2. In addition, the dielectric material layer 161 may also be deposited on the interconnect layer 132 and around the first bonding seal ring 125A and the second bonding seal ring 125B. At the same time, the dielectric material layer 161 may also be deposited on the conductive layers 118A and 118B. In some embodiments, the dielectric material layer 161 may be formed by a blanket deposition process, such as a CVD, PVD, or ALD process, and the composition of the dielectric material layer 161 may be, for example, silicon oxide. Then, a portion of the dielectric material layer 161 on the conductive layers 118A and 118B may be removed by an etching process to expose the conductive layers 118A and 118B. In addition, another portion of the dielectric material layer 161 on the interconnect layer 132 may also be removed by this etching process to form a dielectric film 160 and expose the bonding pad 154 on the dicing line SL. In addition, a portion of the dielectric material layer 161 on the platform of the step structure 150 may also be removed by this etching process to form a sealing layer 170, and the sealing layer 170 fills the vent hole 140 to complete the MEMS package 100 of FIG. 4.

According to an embodiment of the present disclosure, a microelectromechanical package includes various MEMS components packaged under different pressures. In some embodiments, the MEMS package may include an inertial measurement unit (IMU), and the inertial measurement unit may include a first MEMS component such as a gyroscope, and a second MEMS component such as an accelerometer, the first MEMS component and the second MEMS component requiring different vacuum levels and different anti-adhesion requirements, and integrated on the same chip. In one embodiment, one or more vents may be provided laterally through the second keyed sealing ring, and the vents are connected to the second cavity to adjust the pressure in the second cavity, and the height of these vents is substantially the same as the thickness of the second keyed sealing ring. In another embodiment, one or more vents may be formed in the second bonding layer between the second component substrate and the second supporting substrate, and the vents are connected to the second cavity to adjust the pressure in the second cavity, and the height of these vents is substantially the same as the thickness of the second bonding layer. According to the embodiment disclosed herein, after the component wafer is bonded to the supporting wafer and the CMOS wafer, the second pressure in the second cavity may be adjusted through the vents so that the second pressure is different from the first pressure in the first cavity.

In addition, during the process step of adjusting the pressure in the second cavity, an anti-adhesion coating can be formed on the second MEMS element through the vent. In addition, the MEMS package can also include a platform structure outside the vent. By depositing a dielectric film on the platform structure, the vent with a smaller height can be easily re-sealed, thereby improving the reliability of sealing the vent. Therefore, the MEMS package disclosed in the present invention can adjust the pressure in different cavities after bonding, and form an anti-adhesion coating on different MEMS elements after bonding, so that the packaging process of the MEMS package containing various MEMS elements with different cavity pressures is simplified, and the footprint of the MEMS package can also be reduced.

The above is only the preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

100:Micro-electromechanical packaging

100A: First MEMS area

100B: Second MEMS area

SL: Cutting Road

110A: The first supporting substrate

110B: Second supporting substrate

112: First cavity

114: Second cavity

116A: First bonding layer

116B: Second bonding layer

118A, 118B: Conductive layer

120A: First component substrate

120B: Second component substrate

122: First MEMS element

124: Second MEMS element

125A: First key sealing ring

125B: Second key sealing ring

126: Bonding materials

127: Groove

130: Wafer

132: Interconnection layer

134: Protective layer

140: Ventilation holes/holes

145: Anti-adhesion coating

154:Joint pad

160: Dielectric film

Claims (20)

A micro-electromechanical system package comprises: a wafer; an interconnection layer disposed on the wafer; a first component substrate comprising a first micro-electromechanical system component and disposed on the wafer; a second component substrate comprising a second micro-electromechanical system component, which is laterally spaced from the first component substrate and disposed on the wafer; a first bonding sealing ring disposed under the first component substrate and bonded to the interconnection layer; a second bonding sealing ring disposed under the second component substrate and bonded to the interconnection layer; A first supporting substrate including a first cavity and bonded to the first element substrate; a second supporting substrate including a second cavity and bonded to the second element substrate; a hole disposed in the second bonding sealing ring; and a dielectric film disposed on the interconnecting layer and adjacent to the first bonding sealing ring and the second bonding sealing ring, wherein the first cavity has a first pressure, the second cavity has a second pressure, and the second pressure is different from the first pressure. A micro-electromechanical system package as described in claim 1, wherein the hole laterally passes through the second bonding seal ring and is connected to the second cavity to serve as a vent hole, and a portion of the vent hole is filled with the dielectric film. A micro-electromechanical package as described in claim 2, wherein the height of the vent hole is the same as the thickness of the second bonding sealing ring, and the width of the vent hole is between 1 micron and 100 microns. A microelectromechanical package as described in claim 1, wherein the first microelectromechanical component includes a gyroscope, the second microelectromechanical component includes an accelerometer, and the second pressure is greater than the first pressure. The micro-electromechanical system package as described in claim 1 further includes an anti-adhesion coating layer disposed longitudinally on the second component substrate. The micro-electromechanical package as described in claim 1 further includes a first bonding layer disposed between the first component substrate and the first supporting substrate, and a second bonding layer disposed between the second component substrate and the second supporting substrate. A micro-electromechanical package as described in claim 6, wherein the hole vertically passes through the second bonding seal ring and extends through the second component substrate. The micro-electromechanical package as described in claim 7 further includes a vent hole disposed in the second bonding layer, the vent hole extending laterally between the second component substrate and the second supporting substrate, and the vent hole is connected to the second cavity and the hole. A micro-electromechanical package as described in claim 8, wherein the second component substrate and the second supporting substrate form a step structure, and the vent hole is located in the step structure. The micro-electromechanical system package as described in claim 9 further includes a sealing layer filling a portion of the vent hole, and the sealing layer is on the step structure. A method for manufacturing a micro-electromechanical package, comprising: providing a support wafer, comprising forming a first cavity and a second cavity in the support wafer; providing a component wafer, comprising: forming a first micro-electromechanical component and a second micro-electromechanical component laterally separated from each other in the component wafer; forming a first bonding seal ring and a second bonding seal ring, respectively corresponding to the first micro-electromechanical component and the second micro-electromechanical component; forming a hole in the second bonding seal ring; and forming two pre-cut lines in the component wafer, and located between the first micro-electromechanical component and the second micro-electromechanical component. The invention relates to a method for forming a microelectromechanical device (MEMS) wafer between two pre-cut lines; bonding the support wafer to the element wafer, wherein the first cavity is located directly above the first MEMS element and the second cavity is located directly above the second MEMS element; providing a wafer, including forming an interconnect layer on the wafer; bonding the element wafer to the interconnect layer on the wafer under a first pressure; removing a portion of the support wafer and a portion of the element wafer between the two pre-cut lines to expose the hole in the second bonding seal ring to an ambient pressure; and forming a dielectric film on the interconnect layer. A method for manufacturing a micro-electromechanical system package as described in claim 11, wherein the hole laterally passes through the second keyed sealing ring and is connected to the second cavity to serve as a vent hole, and the vent hole is resealed by the dielectric film under a second pressure, and the second pressure is different from the first pressure. The manufacturing method of the micro-electromechanical system package as described in claim 12 further includes depositing an anti-adhesion coating on the second micro-electromechanical system element in a longitudinal direction through the vent hole. The manufacturing method of the micro-electromechanical system package as described in claim 11, wherein the formation of the dielectric film includes: depositing a dielectric material layer on the interconnection layer, and the dielectric material layer is located around the first bonding sealing ring and the second bonding sealing ring; and removing a portion of the dielectric material layer on the interconnection layer to expose a bonding pad. The manufacturing method of the micro-electromechanical package as described in claim 11 further includes forming a bonding layer between the support wafer and the component wafer. A method for manufacturing a micro-electromechanical system package as described in claim 15, wherein the hole vertically passes through the second bonding seal ring and further extends to pass through the device wafer. The manufacturing method of the micro-electromechanical package as described in claim 16, before bonding the component wafer to the interconnection layer on the wafer, further includes removing a portion of the bonding layer between the support wafer and the component wafer through the hole to form a vent hole, and the vent hole is connected to the second cavity and the hole. A method for manufacturing a microelectromechanical package as described in claim 17, wherein one of the two pre-cut lines has a protruding portion corresponding to the hole in the second bonding seal ring when viewed from above, and after removing the portion of the support wafer and the portion of the component wafer located between the two pre-cut lines, a first component substrate including the first microelectromechanical component, a second component substrate including the second microelectromechanical component, a first support substrate located directly above the first microelectromechanical component, and a second support substrate located directly above the second microelectromechanical component are formed, and the second support substrate and the second component substrate form a step structure, and the vent hole is located in the step structure. A method for manufacturing a micro-electromechanical system package as described in claim 18, wherein forming the dielectric film includes: depositing a dielectric material layer on the interconnect layer, located around the first bonding seal ring and the second bonding seal ring, and the dielectric material layer is also deposited on the step structure to seal the vent under a second pressure different from the first pressure; removing a portion of the dielectric material layer on the interconnect layer to expose a bonding pad; and removing another portion of the dielectric material layer on the step structure to form a sealing layer to fill a portion of the vent. The method for manufacturing a micro-electromechanical system package as described in claim 17 further includes depositing an anti-adhesion coating on the second micro-electromechanical system element in a longitudinal direction through the vent hole.