WO2022156596A1 - Mems传感器及其制作方法 - Google Patents

Mems传感器及其制作方法 Download PDF

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Publication number
WO2022156596A1
WO2022156596A1 PCT/CN2022/071941 CN2022071941W WO2022156596A1 WO 2022156596 A1 WO2022156596 A1 WO 2022156596A1 CN 2022071941 W CN2022071941 W CN 2022071941W WO 2022156596 A1 WO2022156596 A1 WO 2022156596A1
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Prior art keywords
welding
ring
layer
welding ring
area
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PCT/CN2022/071941
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English (en)
French (fr)
Inventor
宋亚伟
宋学谦
迟海
Original Assignee
杭州海康微影传感科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Priority claimed from CN202110083903.0A external-priority patent/CN112758884A/zh
Priority claimed from CN202110082211.4A external-priority patent/CN112758883A/zh
Application filed by 杭州海康微影传感科技有限公司 filed Critical 杭州海康微影传感科技有限公司
Priority to EP22742075.9A priority Critical patent/EP4282811A1/en
Publication of WO2022156596A1 publication Critical patent/WO2022156596A1/zh

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
    • B81C1/00261—Processes for packaging MEMS devices
    • B81C1/00269—Bonding of solid lids or wafers to the substrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C2203/00—Forming microstructural systems
    • B81C2203/01—Packaging MEMS
    • B81C2203/0172—Seals
    • B81C2203/019—Seals characterised by the material or arrangement of seals between parts

Definitions

  • the present application relates to the technical field of semiconductor devices, and in particular, to a MEMS sensor and a manufacturing method thereof.
  • Hermetic packaging is a common packaging requirement in the MEMS field.
  • MEMS devices such as acceleration sensors, pressure sensors, and angular velocity sensors have movable parts inside, and it is necessary to provide air-tight cavities for movable parts to ensure that the movable parts have less damping and static friction inside the cavity.
  • MEMS devices such as uncooled infrared focal plane detectors have microbolometers inside, and it is necessary to reduce the vacuum degree inside the device to ensure a small thermal radiation heat loss. When the air pressure inside the cavity rises to the point where the vacuum degree exceeds the set standard, the sensitivity of the device will decrease below the standard value, causing the device to fail. Therefore, hermetic sealing is a key factor in determining device life.
  • the present application discloses a MEMS sensor and a manufacturing method thereof.
  • a first aspect of the present application provides a MEMS sensor, comprising:
  • a substrate comprising a MEMS structure, a first welding area disposed around the MEMS structure, and a first welding ring located in the first welding area;
  • a cover plate including a second welding area and a second welding ring located in the second welding area; the base plate and the cover plate are welded together by the first welding ring and the second welding ring to form a seal structure to confine the MEMS structure in the vacuum cavity; at least one of the first welding area and the second welding area has annular grooves or annular protrusions distributed along the circumferential direction, the first welding area A welding ring is located on the first welding area and the second welding ring is located on the second welding area.
  • a second aspect of the present application provides a method for fabricating the above-mentioned MEMS sensor, comprising:
  • a prefabricated substrate and a prefabricated cover plate are respectively provided, the prefabricated substrate includes a MEMS structure, and a first welding area arranged around the MEMS structure; the prefabricated cover plate includes a second welding area;
  • annular grooves or annular protrusions distributed along the circumferential direction on at least one of the first welding area and the second welding area;
  • a first solder ring is formed on the first bonding area, so that the prefabricated substrate forms a substrate, the first bonding ring is located on the first bonding area; a second bonding ring is formed on the second bonding area a welding ring such that the prefabricated cover plate forms a cover plate, the second welding ring being located on the second welding zone;
  • the first welding ring and the second welding ring are welded together in a vacuum environment, so that the substrate and the cover plate form a sealing structure, so as to confine the MEMS structure in a vacuum cavity.
  • a third aspect of the present application provides a MEMS sensor, comprising:
  • a substrate comprising a MEMS structure, a first inner solder ring arranged around the MEMS structure, and a first outer solder ring arranged around the first inner solder ring;
  • a cover plate comprising a second inner welding ring and a second outer welding ring arranged around the second inner welding ring; the base plate and the cover plate are welded to the second inner welding ring through the first inner welding ring
  • the rings are welded together to form a first sealing structure, the first sealing structure confines the MEMS structure in a vacuum cavity; the substrate and the cover plate are welded to the second outer through the first outer welding ring
  • the rings are welded together to form a second sealing structure, and a vacuum sandwich cavity is formed between the second sealing structure and the first sealing structure.
  • FIG. 1 is a schematic cross-sectional structure diagram of a MEMS sensor according to an embodiment of the present application
  • FIG. 2 is a schematic top view of the structure of the substrate with the first welding ring removed;
  • Fig. 3 is the bottom view structure schematic diagram of the cover plate with the second welding ring removed;
  • FIG. 4 is a flowchart of a method for manufacturing a MEMS sensor according to an embodiment of the present application
  • 5 to 10 are schematic diagrams of intermediate structures corresponding to the process in FIG. 4;
  • FIG. 11 is a schematic cross-sectional structural diagram of a partial structure of a MEMS sensor according to another embodiment of the present application.
  • FIG. 12 is a schematic cross-sectional structural diagram of a partial structure of a MEMS sensor according to another embodiment of the present application.
  • FIG. 13 is a schematic cross-sectional structure diagram of a MEMS sensor according to still another embodiment of the present application.
  • FIG. 14 is a schematic cross-sectional structure diagram of a MEMS sensor according to another embodiment of the present application.
  • FIG. 15 is a schematic cross-sectional structure diagram of a MEMS sensor according to another embodiment of the present application.
  • 16 is a schematic cross-sectional structure diagram of a MEMS sensor according to still another embodiment of the present application.
  • 17 is a schematic cross-sectional structural diagram of a partial structure of a MEMS sensor according to another embodiment of the present application.
  • FIG. 18 is a schematic cross-sectional structure diagram of a MEMS sensor according to another embodiment of the present application.
  • FIG. 19 is a schematic top-view structural diagram of a substrate in a MEMS sensor according to still another embodiment of the present application.
  • FIG. 20 is a bottom structural schematic diagram of a cover plate in a MEMS sensor according to still another embodiment of the present application.
  • FIG. 1 is a schematic cross-sectional structure diagram of a MEMS sensor according to an embodiment of the present application.
  • FIG. 2 is a schematic top view of the structure of the substrate with the first welding ring removed;
  • FIG. 3 is a bottom view of the structure of the cover plate with the second welding ring removed.
  • the MEMS sensor 1 of this embodiment includes:
  • the substrate 11 includes a MEMS structure 110 , a first bonding area 111 disposed around the MEMS structure 110 , and a first bonding ring 112 located in the first bonding area 111 ;
  • the cover plate 12 includes a second welding area 121 and a second welding ring 122 located in the second welding area 121; the substrate 11 and the cover plate 12 are welded together by the first welding ring 112 and the second welding ring 122 to form the sealing structure 13 , so as to confine the MEMS structure 110 in the vacuum cavity 13a; the first welding area 111 has annular grooves 14 distributed along the circumferential direction, the second welding area 121 has annular protrusions 15 distributed along the circumferential direction, and the first welding area 111 has annular grooves 14 distributed along the circumferential direction.
  • the welding ring 112 is conformally located on the first welding area 111 and the second welding ring 122 is conformally located on the second welding area 121 .
  • the substrate 11 may include a first semiconductor substrate on which the MEMS structure 110 is disposed.
  • the MEMS structure 110 may depend on the type of the MEMS sensor 1 .
  • the MEMS structure 110 may include a fixed electrode and a movable electrode.
  • the movable electrode can be a cantilever beam supported at one end, or a cantilever beam supported at both ends.
  • the MEMS structure 110 includes a photosensitive structure whose upper surface is uncovered. This embodiment does not limit the MEMS structure 110, and only needs to be set in a vacuum environment.
  • the first bonding area 111 has a first passivation layer 113 .
  • the annular groove 14 is located in the first passivation layer 113 .
  • the material of the first passivation layer 113 may be silicon nitride.
  • the first bonding area 111 may have a first dielectric layer, and the annular groove 14 is located in the first dielectric layer.
  • the material of the first dielectric layer may be silicon dioxide.
  • the first bonding pad 111 may have a first semiconductor layer, and the annular groove 14 is located in the first semiconductor layer.
  • the material of the first semiconductor layer may be doped polysilicon or a single crystal silicon substrate.
  • the annular groove 14 is located in a stacked structure of at least two of the first dielectric layer, the first passivation layer and the first semiconductor layer. This embodiment does not limit the material type of the first welding area 111 .
  • the cover plate 12 may include a second semiconductor substrate.
  • the second bonding area 121 has a second dielectric layer 123 .
  • the annular protrusion 15 is located on the second dielectric layer 123 .
  • the material of the annular protrusion 15 and the second dielectric layer 123 may be silicon dioxide.
  • the second bonding area 121 may have a second passivation layer, and the annular protrusion 15 is located on the second passivation layer.
  • the material of the annular protrusion 15 and the second passivation layer may be silicon nitride.
  • the second bonding pad 121 may have a second semiconductor layer, and the annular protrusion 15 is located on the second semiconductor layer.
  • the material of the annular protrusion 15 and the second semiconductor layer may be doped polysilicon, or may be a single crystal silicon substrate.
  • the second pad 121 may have a stacked structure of at least two of the second dielectric layer, the second passivation layer and the second semiconductor layer, and the annular protrusion 15 is located on the stacked structure.
  • the material of the annular protrusion 15 is the same as the material of the layer in contact with the annular protrusion 15 in the above-mentioned laminated structure, or the annular protrusion 15 is also the same as the laminated structure in the second welding area 121. layer structure. This embodiment does not limit the material type of the second welding area 121 .
  • the material of the first welding ring 112 and the second welding ring 122 is metal, such as copper or aluminum.
  • the fact that the first welding ring 112 is conformally located on the first welding area 111 means that the thickness of the first welding ring 112 is relatively thin, and the annular recessed area enclosed by the surface of the first welding ring 112 away from the first welding area 111 is vertically
  • the cross-section in the circumferential direction corresponds to the shape of the cross-section in the vertical circumferential direction of the annular groove 14 .
  • the cross section of the annular groove 14 along the vertical circumferential direction is triangular
  • the cross section of the annular recessed area enclosed by the surface of the first welding ring 112 away from the first welding area 111 along the vertical circumferential direction is a triangle.
  • the cross section of the annular groove 14 in the vertical circumferential direction is square
  • the cross section of the annular recessed area enclosed by the surface of the first welding ring 112 away from the first welding area 111 is square in the vertical circumferential direction.
  • the cross section of the annular groove 14 along the vertical circumferential direction is a rectangle
  • the cross section of the annular recessed area enclosed by the surface of the first welding ring 112 away from the first welding area 111 along the vertical circumferential direction is a rectangle (refer to FIG. 1 ).
  • the cross section of the annular groove 14 in the vertical circumferential direction is a normal trapezoid
  • the cross section of the annular recessed area enclosed by the surface of the first welding ring 112 away from the first welding area 111 is a normal trapezoid in the vertical circumferential direction.
  • the cross section of the annular groove 14 in the vertical circumferential direction is an inverted trapezoid
  • the cross section of the annular recessed area enclosed by the surface of the first welding ring 112 away from the first welding area 111 is an inverted trapezoid in the vertical circumferential direction.
  • the fact that the second welding ring 122 is conformally located on the second welding area 121 means that the thickness of the second welding ring 122 is relatively thin, and the annular raised area formed by the surface of the second welding ring 122 away from the second welding area 121 is vertically
  • the cross-sectional shape in the circumferential direction corresponds to the cross-sectional shape of the annular protrusion 15 in the vertical circumferential direction.
  • the cross section of the annular protrusion 15 along the vertical circumferential direction is triangular
  • the cross section of the annular raised area formed by the surface of the second welding ring 122 away from the second welding area 121 along the vertical circumferential direction is a triangle.
  • the cross section of the annular protrusion 15 along the vertical circumferential direction is square
  • the cross section of the annular raised area formed by the surface of the second welding ring 122 away from the second welding area 121 along the vertical circumferential direction is square.
  • the cross section of the annular protrusion 15 along the vertical circumferential direction is a rectangle
  • the cross section of the annular raised area formed on the surface of the second welding ring 122 away from the second welding area 121 along the vertical circumferential direction is a rectangle (refer to FIG. 1 ).
  • the cross section of the annular protrusion 15 along the vertical circumferential direction is a normal trapezoid
  • the cross section of the annular raised area formed on the surface of the second welding ring 122 away from the second welding area 121 along the vertical circumferential direction is a normal trapezoid.
  • the cross section of the annular protrusion 15 in the vertical circumferential direction is an inverted trapezoid
  • the cross section of the annular protrusion area formed on the surface of the second welding ring 122 away from the second welding area 121 is an inverted trapezoid in the vertical circumferential direction.
  • the annular groove 14 and the annular protrusion 15 can engage the first welding ring 112 with the second welding ring 122 .
  • the shape and size of the solder layer (not shown) match the engagement surfaces of the first solder ring 112 and the second solder ring 122 .
  • the solution can manufacture uneven structures, and the advantages are that the effective length of the leakage channel of the outside gas entering the vacuum chamber 13a can be increased, thereby reducing the gas leakage rate and improving the reliability and life of the MEMS sensor 1 .
  • the temperature change of the MEMS structure 110 after receiving the target infrared radiation is very weak.
  • the vacuum degree in the vacuum chamber 13a is required to be below E-3 Torr.
  • the uneven structure of the first welding ring 112 and the second welding ring 122 reduces the packaging leak rate of the vacuum chamber 13a and prolongs the vacuum degree in the chamber, thereby directly ensuring the reliability of the infrared detector.
  • the welding surfaces of the first welding ring 112 and the second welding ring 122 are non-planar uneven structures, which can improve the shear strength of the MEMS sensor 1 and thus improve the impact resistance reliability.
  • the annular groove 14 and the annular protrusion 15 engage the thin first welding ring 112 and the second welding ring 122, which can further improve the performance of the MEMS sensor 1. Shear strength, thereby improving impact reliability.
  • the ratio between the depth D of the annular groove 14 and the width W1 of the annular groove 14 is greater than 1/10; the height H of the annular protrusion 15 The ratio to the width W2 of the annular protrusion 15 is greater than 1/10.
  • the first solder ring 112 and the second solder ring 122 are soldered together by indium-based solder.
  • tin-based solder can also be used for soldering.
  • the organic flux in the solder paste will volatilize and release gas, resulting in an increase in the pressure in the vacuum chamber 13 a.
  • indium-based solder or tin-based solder has no organic flux, it will not release gas at high temperature, and will not affect the vacuum degree in the vacuum chamber 13a.
  • the indium-based solder and the tin-based solder are alloys with indium and tin as the main components and doped with other metals such as gold, silver, and copper.
  • Indium-based solder is, for example, In97Ag3 or In95Ag5.
  • FIG. 4 is a flowchart of a production method.
  • 5 to 10 are schematic diagrams of intermediate structures corresponding to the process in FIG. 4 .
  • a prefabricated substrate 11 ′ and a prefabricated cover plate 12 ′ are respectively provided.
  • the prefabricated substrate 11 ′ includes the MEMS structure 110 , and the The first welding area 111 ; the prefabricated cover plate 12 ′ includes the second welding area 121 .
  • the prefabricated substrate 11' may include a first semiconductor substrate on which the MEMS structure 110 is disposed.
  • the MEMS structure 110 may depend on the type of the MEMS sensor 1 .
  • the MEMS structure 110 may include a fixed electrode and a movable electrode.
  • the movable electrode can be a cantilever beam supported at one end, or a cantilever beam supported at both ends.
  • the MEMS structure 110 includes a photosensitive structure whose upper surface is uncovered. This embodiment does not limit the MEMS structure 110, and only needs to be set in a vacuum environment.
  • the first bonding area 111 has a first passivation layer 113 .
  • the material of the first passivation layer 113 may be silicon nitride.
  • the first bonding pad 111 may have a first dielectric layer or a first semiconductor layer.
  • the material of the first dielectric layer may be silicon dioxide.
  • the material of the first semiconductor layer may be doped polysilicon or a single crystal silicon substrate.
  • the first bonding pad 111 has a stacked structure including at least two of the first dielectric layer, the first passivation layer and the first semiconductor layer. This embodiment does not limit the material type of the first welding area 111 .
  • the prefabricated cover plate 12' may include a second semiconductor substrate.
  • the second bonding area 121 has a second dielectric layer 123 .
  • the material of the second dielectric layer 123 may be silicon dioxide.
  • the second bonding area 121 may have a second passivation layer or a second semiconductor layer.
  • the material of the second passivation layer may be silicon nitride.
  • the material of the second semiconductor layer may be doped polysilicon or a single crystal silicon substrate.
  • the second bonding pad 121 has a stacked structure including at least two of the second dielectric layer, the second passivation layer and the second semiconductor layer. This embodiment does not limit the material type of the second welding area 121 .
  • annular grooves 14 distributed along the circumferential direction are formed in the first welding area 111 ; annular grooves 14 distributed along the circumferential direction are formed in the second welding area 121 .
  • step S2 may include:
  • Step S21 forming a photoresist layer on the prefabricated substrate 11' and the prefabricated cover plate 12' respectively; then exposing the photoresist layer by using a corresponding mask; by developing, forming respective patterned photoresist Floor.
  • Step S22 using the corresponding patterned photoresist layer as a mask, dry etching the first passivation layer 113 to form the annular groove 14 in the first passivation layer 113;
  • the photoresist layer is used as a mask, and the second dielectric layer 123 is dry-etched to form the annular protrusion 15 in the second dielectric layer 123 .
  • Step S23 ashing to remove the remaining photoresist layer.
  • a first solder ring 112 is formed in the first soldering area 111 , so that the prefabricated substrate 11 ′ forms the substrate 11 , and the first solder ring 112 conforms to the shape
  • the second welding ring 122 is formed on the second welding area 121, so that the prefabricated cover plate 12' forms the cover plate 12, and the second welding ring 122 is conformally located on the second welding area 121. .
  • the material of the first welding ring 112 and the second welding ring 122 is metal, such as copper or aluminum.
  • the first weld ring 112 may be formed through an electron beam evaporation or sputtering process.
  • the second weld ring 122 may also be formed by an electron beam evaporation or sputtering process.
  • the electron beam evaporation or sputtering process may form a metal layer on the entire surface, and the metal layer in the areas other than the first welding area 111 and the second welding area 121 may be removed by a dry etching process or a wet etching process.
  • the thickness of the metal layer is relatively thin.
  • the thickness of the metal layer satisfies: the cross section of the annular recessed area enclosed by the surface of the metal layer away from the first welding area 111 along the vertical circumferential direction and the annular groove 14 along the vertical circumferential direction
  • the cross-sectional shape is the same.
  • the thickness of the metal layer satisfies: the vertical circumferential section of the annular raised area enclosed by the surface of the metal layer away from the second welding area 121 is consistent with the vertical circumferential section of the annular raised 15 .
  • the prefabricated substrate 11 ′ and the prefabricated cover plate 12 ′ can be immersed in an organic solvent for ultrasonic vibration to clean the residues.
  • the organic solvent can be at least one of acetone, ethanol, diethyl ether, and isopropanol.
  • step S4 in FIG. 4 and as shown in FIG. 1 the first welding ring 112 and the second welding ring 122 are welded together, so that the substrate 11 and the cover plate 12 form the sealing structure 13 , so as to limit the MEMS structure 110 to the sealing structure 13 . inside the vacuum chamber 13a.
  • This step is soldering in a vacuum environment.
  • the soldering may be performed using a vacuum bonder.
  • the vacuum bonding machine the solder reaches the melting point and begins to melt, and the solder spreads rapidly on the first welding ring 112 and the second welding ring 122 to fill the uneven structure.
  • the solder solidifies and the first welding ring 112 and the second welding ring 122 122 forms a radially extending chain-like tooth structure.
  • the first solder ring 112 and the second solder ring 122 are soldered together by indium-based solder.
  • tin-based solder can also be used for soldering. Compared with tin paste solder, since indium-based solder and tin-based solder do not have organic flux, they will not release gas at high temperature, and will not affect the vacuum degree in the vacuum chamber 13a.
  • FIG. 11 is a schematic cross-sectional structural diagram of a partial structure of a MEMS sensor according to another embodiment of the present application.
  • the MEMS sensor 2 and the manufacturing method thereof in this embodiment are substantially the same as the MEMS sensor 1 and the manufacturing method thereof in the above-mentioned embodiment, except that the annular groove 14 and the annular protrusion 15 include two circles.
  • the number of turns of the annular groove 14 and the annular protrusion 15 is the same.
  • the dimensions of each ring of annular grooves 14 are the same, and the above-mentioned dimensions include width and depth; the dimensions of each ring of annular protrusions 15 are also the same, and the above-mentioned dimensions include width and height.
  • the size of each ring of annular grooves 14 may also be different, such as different widths and/or depths; the size of each ring of annular protrusions 15 may also be different, such as different widths and/or heights, corresponding The grooves and protrusions are matched in size.
  • protrusions may correspond to protrusions
  • depressions may correspond to depressions
  • annular groove 14 and the annular protrusion 15 may also include more than two turns.
  • FIG. 12 is a schematic cross-sectional structural diagram of a partial structure of a MEMS sensor according to another embodiment of the present application.
  • the MEMS sensor 3 of the present embodiment and the manufacturing method thereof are substantially the same as the MEMS sensors 1 and 2 of the above-mentioned embodiment and the manufacturing method thereof, the difference is that the first welding ring 112 sequentially includes: The first adhesion layer 112a, the first barrier layer 112b, and the first wetting layer 112c; the second welding ring 122 includes the second adhesion layer 122a, the second barrier layer 122b and the second wetting layer in sequence toward the substrate 11 122c.
  • the first adhesion layer 112a is selected to have good adhesion and thermal expansion coefficient with the material layer disposed in the first bonding area, such as the first passivation layer 113 or the first dielectric layer or the first semiconductor layer. Matching metals such as titanium or chromium.
  • the first barrier layer 112b is a metal with good adhesion to the first wetting layer 112c and the first adhesion layer 112a, the thermal expansion coefficient is between the two layers, and the welding performance is middle, such as nickel.
  • the first wetting layer 112c is also an anti-oxidation layer, and is selected from a metal with stable performance, good wettability, difficult oxidation, and good brazing performance, such as gold.
  • the second adhesion layer 122a is selected from a metal with good adhesion and matching thermal expansion coefficient with the material layer disposed in the second bonding area, such as the second dielectric layer 123 or the second passivation layer or the second semiconductor layer.
  • Metals are, for example, titanium or chromium.
  • the second barrier layer 122b is a metal with good adhesion to the second wetting layer 122c and the second adhesive layer 122a, the thermal expansion coefficient is between the two layers, and the welding performance is middle, such as nickel.
  • the second wetting layer 122c is also an anti-oxidation layer, and is selected from a metal with stable performance, good wettability, difficult oxidation, and good brazing performance, such as gold.
  • only the first welding ring 112 may include the first adhesive layer 112 a , the first barrier layer 112 b and the first wetting layer 121 c in sequence in the direction facing the cover plate 12 ; or only the second welding ring 122 may be facing the substrate 11 .
  • the directions sequentially include: a second adhesion layer 122a, a second barrier layer 122b, and a second wetting layer 122c.
  • the two welding rings 122 form a chain-like tooth structure extending in the radial direction.
  • FIG. 13 is a schematic cross-sectional structure diagram of a MEMS sensor according to another embodiment of the present application.
  • the MEMS sensor 4 and the manufacturing method thereof in this embodiment are substantially the same as the MEMS sensors 1 , 2 , and 3 and the manufacturing method thereof in the above-mentioned embodiment, except that the first welding area 111 has a circumferentially distributed
  • the annular protrusion 15 and the second welding area 121 have annular grooves 14 distributed along the circumferential direction.
  • the annular protrusion 15 and the annular groove 14 can engage the first welding ring 112 with the second welding ring 122 .
  • FIG. 14 is a schematic cross-sectional structure diagram of a MEMS sensor according to still another embodiment of the present application.
  • the MEMS sensor 5 of the present embodiment and the manufacturing method thereof are substantially the same as the MEMS sensors 1 , 2 , 3 , and 4 of the above-mentioned embodiment and the manufacturing method thereof, except that the first welding area 111 has a circumferential direction.
  • the distributed annular grooves 14 and the second welding area 121 are flat.
  • the first welding ring 112 is conformally located on the first welding area 111 , therefore, the surface of the first welding ring 112 away from the first welding area 111 encloses an annular recessed area, and the annular recessed area extends along the vertical circumferential direction.
  • the cross-section corresponds to the cross-sectional shape of the annular groove 14 in the vertical circumferential direction.
  • the second welding ring 122 is conformally located on the second welding area 121 , and thus, the surface of the second welding ring 122 away from the second welding area 121 is flat.
  • the solder layer 16 includes an opposing first surface and a second surface, the shape and size of the first surface match the shape and size of the first solder ring 112 , and the shape and size of the second surface match the shape and size of the second surface.
  • the first welding area 111 may have annular protrusions 15 distributed along the circumferential direction
  • the second welding area 121 may be a plane; or the first welding area 111 may be a plane, and the second welding area 121 may have a circumferential direction Distributed annular grooves 14; or the first welding area 111 is a plane, and the second welding area 121 has annular protrusions 15 distributed along the circumferential direction.
  • FIG. 15 is a schematic cross-sectional structure diagram of a MEMS sensor according to another embodiment of the present application.
  • FIG. 15 is a schematic cross-sectional structure diagram of a MEMS sensor according to another embodiment of the present application.
  • corresponding parts reference may be made to the above-mentioned embodiment, so the relevant parts will not be described in detail.
  • the MEMS sensor 6 of this embodiment includes:
  • the substrate 11 includes a MEMS structure 110, a first inner welding ring 1111 disposed around the MEMS structure 110, and a first outer welding ring 1112 disposed around the first inner welding ring 1111;
  • the cover plate 12 includes a second inner welding ring 1211 and a second outer welding ring 1212 arranged around the second inner welding ring 1211; the base plate 11 and the cover plate 12 are welded by the first inner welding ring 1111 and the second inner welding ring 1211
  • the first sealing structure 17 is formed together, and the first sealing structure 17 confines the MEMS structure 110 in the vacuum cavity 17a; the substrate 11 and the cover plate 12 are formed by welding the first outer welding ring 1112 and the second outer welding ring 1212 together.
  • the second sealing structure 18 forms a vacuum interlayer cavity 18a between the second sealing structure 18 and the first sealing structure 17 .
  • the material of the first inner welding ring 1111 and the first outer welding ring 1112 is metal, such as copper or aluminum.
  • the first inner solder ring 1111 and the first outer solder ring 1112 may be located on the same layer as the metal layer in the MEMS structure 110 . The three can be made in the same process, or they can be made separately.
  • the cover plate 12 may include a second semiconductor substrate.
  • the material of the second inner welding ring 1211 and the second outer welding ring 1212 is metal, such as copper or aluminum.
  • the cross-sectional dimensions of the first inner welding ring 1111 and the second inner welding ring 1211 are the same, and the cross-sectional dimensions of the first outer welding ring 1112 and the second outer welding ring 1212 are the same, so that the welding can be completely aligned, Improve welding effect.
  • the welding of the first inner welding ring 1111 and the second inner welding ring 1211 and the welding of the first outer welding ring 1112 and the second outer welding ring 1212 can be realized by using indium-based solder or tin-based solder.
  • Indium-based solder and tin-based solder are alloys with indium and tin as the main components, doped with other metals such as gold, silver, and copper.
  • Indium-based solder is, for example, In97Ag3 or In95Ag5.
  • the welding of the first inner welding ring 1111 and the second inner welding ring 1211 and the welding of the first outer welding ring 1112 and the second outer welding ring 1212 are performed in the same vacuum environment, so that the MEMS sensor 1 is delivered from the factory.
  • the pressure in the vacuum interlayer cavity 18a is equal to the pressure in the vacuum cavity 17a, that is, the initial pressure in the vacuum interlayer cavity 18a is equal to the initial pressure in the vacuum cavity 17a.
  • the thicknesses of the first inner welding ring 1111 and the first outer welding ring 1112 can be equal or different, and the thicknesses of the second inner welding ring 1211 and the second outer welding ring 1212 (the top of the welding ring vertical distance from the cover) can be equal or unequal.
  • the sum of the thicknesses of the first inner welding ring 1111 and the second inner welding ring 1211 is equal to the sum of the thicknesses of the first outer welding ring 1112 and the second outer welding ring 1212 .
  • the welding of the first inner welding ring 1111 and the second inner welding ring 1211 may be performed in a first vacuum environment, and the welding of the first outer welding ring 1112 and the second outer welding ring 1212 in a second vacuum environment to carry out, the pressure of the second vacuum environment is less than or much less than the pressure of the external environment, and is greater than or slightly greater than the pressure of the first vacuum environment.
  • the ambient pressure is generally one atmosphere. Therefore, the initial pressure in the vacuum interlayer cavity 18a is higher or slightly larger than the initial pressure in the vacuum cavity 17a, but smaller or much smaller than the external environment pressure.
  • the pressure difference between the initial pressure in the vacuum interlayer chamber and the initial pressure in the vacuum chamber can also be controlled within a predetermined range, regardless of the initial pressure in the vacuum interlayer chamber and the vacuum chamber. Whichever is larger is the initial pressure in the body, as long as the difference between the two is within the predetermined range and much smaller than the pressure of the external environment.
  • the pressure difference between the two can be achieved by controlling the amount of the getter in the vacuum interlayer cavity and the amount of the getter in the vacuum cavity to be within a predetermined range, where the predetermined range can be within E-3 Torr or other Values that can achieve normal operation of the device in the vacuum chamber.
  • the leakage of the gas in the external environment into the vacuum chamber 17a includes: the first step, the gas in the external environment leaks into the vacuum interlayer chamber 18a; the second step, the gas in the vacuum interlayer chamber 18a leaks into the vacuum chamber 17a.
  • the above two steps of leakage both take time, which can prolong the time for the MEMS sensor 1 to fail.
  • the ratio of the distance L between the first inner welding ring 1111 and the first outer welding ring 1112 to the width W of the first inner welding ring 1111 (or the first outer welding ring 1112 ) ranges from 0.1 to 0.3 (including the endpoint values), in order to reduce the width of the vacuum interlayer cavity 18a and improve the surface utilization rate of the substrate 11 .
  • FIG. 16 is a schematic cross-sectional structure diagram of a MEMS sensor according to another embodiment of the present application.
  • the MEMS sensor 7 of this embodiment is substantially the same as the MEMS sensor 6 of the previous embodiment, except that the first getter layer 20 is provided in the part of the substrate 11 and the cover plate 12 surrounding the vacuum cavity 17 a , the part of the substrate 11 and the cover plate 12 enclosing the vacuum interlayer cavity 18a is provided with a second getter layer 21 .
  • the getter layer 20 is not provided on the MEMS sensor.
  • the first getter layer 20 and the second getter layer 21 are used for absorbing gas, correspondingly reducing the vacuum degree in the vacuum chamber 17a and the vacuum degree in the vacuum interlayer chamber 18a.
  • the first getter layer 20 and the second getter layer 21 are before the welding of the first inner welding ring 1111 and the second inner welding ring 1211 and the first outer welding ring 1112 and the second outer welding ring 1212 to activate. Activation can be achieved by heating the first getter layer 20 and the second getter layer 21 .
  • the material of the first getter layer 20 and/or the second getter layer 21 may include zirconium or titanium.
  • the first getter layer 20 may be provided only on the part of the substrate 11 enclosing the vacuum cavity 17a, or only on the part of the cover plate 12 enclosing the vacuum cavity 17a.
  • the second getter layer 21 may be provided only on the part of the substrate 11 that encloses the vacuum interlayer cavity 18a, or only the part of the cover plate 12 that encloses the vacuum interlayer cavity 18a.
  • the first getter layer 20 can be used between the first inner weld ring 1111 and the second inner weld ring 1211 , and the first outer weld ring 1112 and the second outer weld ring 1212 Activate after soldering.
  • the vacuum chamber 17a and the vacuum interlayer chamber 18a are welded in the same vacuum environment. pressure is equal.
  • the first getter layer 20 is activated, and the first getter layer 20 absorbs the gas in the vacuum chamber 17a, which can reduce the initial pressure of the vacuum chamber 17a, so that the initial pressure of the vacuum interlayer chamber 18a is slightly larger than that of the vacuum chamber.
  • Initial pressure of body 17a The above-mentioned ambient pressure during welding, that is, the initial pressure of the vacuum interlayer cavity 18a, is much smaller than the external ambient pressure. Activation can be achieved by heating the first getter layer 20 .
  • the photosensitive structure corresponds to a photosensitive region of the cover plate, and the remaining regions of the cover plate are non-photosensitive regions. If the first getter layer 20 reduces the light transmittance, it is arranged in the non-photosensitive area.
  • the substrate 11 and/or the cover plate 12 further include a layer of outgassing material, such as the circuit structure of the MEMS sensor 7 .
  • the circuit structure uses photoresist as a mask layer in the patterning process, and the photoresist may have residues in the removal process and remain in the circuit structure; the residual photoresist may be used in some environments of the MEMS sensor 7 , for example, gas is released at high temperature, and thus, the residual photoresist is a layer of outgassing material.
  • the outgassing material layer is disposed within the vacuum interlayer cavity 18a as opposed to being disposed within the vacuum cavity 17a.
  • FIG. 17 is a schematic cross-sectional structural diagram of a partial structure of a MEMS sensor according to another embodiment of the present application.
  • the MEMS sensor 8 of this embodiment is substantially the same as the MEMS sensors 6 and 7 of the previous embodiment, except that the first inner welding ring 1111 and the first outer welding ring 1112 sequentially include: The first adhesive layer 11a, the first barrier layer 11b, and the first wetting layer 11c; the second inner solder ring 1211 and the second outer solder ring 1212 toward the substrate 11 sequentially include: a second adhesive layer 12a, a second barrier layer 12b and second wetting layer 12c.
  • the first adhesive layer 11a is selected from a metal having good adhesion to the substrate 11, such as the first semiconductor substrate, and matching the thermal expansion coefficient, and the above metal includes, for example, titanium or chromium.
  • the first barrier layer 11b is a metal with good adhesion to the first wetting layer 11c and the first adhesion layer 11a, the thermal expansion coefficient is between the two layers, and the welding performance is middle, such as nickel.
  • the first wetting layer 11c is also an anti-oxidation layer at the same time, and a metal with stable performance, good wettability, hard oxidation and good brazing performance is selected, and the above-mentioned metal includes gold, for example.
  • the second adhesive layer 12a is selected from a metal having good adhesion to the cover plate 12, such as the second semiconductor substrate, and matching the thermal expansion coefficient, such as titanium or chromium.
  • the second barrier layer 12b is a metal with good adhesion to the second wetting layer 12c and the second adhesive layer 12a, the thermal expansion coefficient is between the two layers, and the welding performance is intermediate, such as nickel.
  • the second wetting layer 12c is also an anti-oxidation layer, and is selected from a metal with stable performance, good wettability, difficult oxidation and good brazing performance, and the above metal includes gold, for example.
  • only the first inner welding ring 1111 may include the first adhesive layer 11a, the first barrier layer 11b, and the first wetting layer 11c in sequence toward the cover plate 12; or only the first outer welding ring 1112 may be directed toward the cover plate 12.
  • the cover plate 12 includes the first adhesive layer 11a, the first barrier layer 11b and the first wetting layer 11c in sequence; or only the second inner welding ring 1211 includes the second adhesive layer 12a, the second inner welding ring 1211 toward the substrate 11 in order.
  • the two barrier layers 12b and the second wetting layer 12c; or only the second outer solder ring 1212 includes the second adhesion layer 12a, the second barrier layer 12b and the second wetting layer 12c in sequence toward the substrate 11 .
  • FIG. 18 is a schematic cross-sectional structure diagram of a MEMS sensor according to still another embodiment of the present application.
  • the MEMS sensor 9 of this embodiment is substantially the same as the MEMS sensors 6 , 7 , and 8 of the previous embodiment, except that the substrate 11 further includes a first intermediate welding ring 1113 , and the first intermediate welding ring 1113 is disposed on the Between the first inner welding ring 1111 and the first outer welding ring 1112; the cover plate 12 further includes a second intermediate welding ring 1213, and the second intermediate welding ring 1213 is arranged between the second inner welding ring 1211 and the second outer welding ring 1212.
  • the substrate 11 and the cover plate 12 are welded together by the first intermediate welding ring 1113 and the second intermediate welding ring 1213 to form a third sealing structure 19, and a first vacuum interlayer is formed between the third sealing structure 19 and the first sealing structure 17
  • a second vacuum interlayer cavity 19b is formed between the cavity 19a, the third sealing structure 19 and the second sealing structure 18.
  • the initial pressure in the first vacuum interlayer chamber 19a and the initial pressure in the second vacuum interlayer chamber 19b are equal to the initial pressure in the vacuum chamber 17a.
  • the leakage of the gas in the external environment into the vacuum chamber 17a includes: the first step, the gas in the external environment leaks into the second vacuum interlayer chamber 19b; the second step, the gas in the second vacuum interlayer chamber 19b The gas leaks into the first vacuum interlayer cavity 19a; in the third step, the gas in the first vacuum interlayer cavity 19a leaks into the vacuum cavity 17a.
  • the MEMS sensor 9 of this embodiment can further reduce the leakage rate of gas, and improve reliability and life.
  • two or more intermediate sealing structures may be disposed between the first sealing structure 17 and the second sealing structure 18 to further reduce the gas leakage rate.
  • FIG. 19 is a schematic top-view structural diagram of a substrate in a MEMS sensor according to another embodiment of the present application.
  • FIG. 20 is a schematic bottom view of a cover plate in a MEMS sensor according to another embodiment of the present application. Referring to FIGS.
  • the MEMS sensor of this embodiment is substantially the same as the MEMS sensors 6 , 7 , 8 , and 9 of the previous embodiment, except that the difference between the first inner welding ring 1111 and the first outer welding ring 1112 is A first connection bridge 22 is provided, the first connection bridge 22 includes a first inner connection end 22a and a first outer connection end 22b, the first inner connection end 22a is connected to the first inner welding ring 1111, and the first outer connection end 22b is connected In the first outer welding ring 1112, the thickness of the first inner connecting end 22a is equal to the thickness of the first inner welding ring 1111, and the thickness of the first outer connecting end 22b is equal to the thickness of the first outer welding ring 1112; A second connecting bridge 23 is arranged between the ring 1211 and the second outer welding ring 1212.
  • the second connecting bridge 23 includes a second inner connecting end 23a and a second outer connecting end 23b, and the second inner connecting end 23a is connected to the second inner connecting end 23a.
  • the welding ring 1211, the second outer connecting end 23b is connected to the second outer welding ring 1212, the thickness of the second inner connecting end 23a is equal to the thickness of the second inner welding ring 1211, and the thickness of the second outer connecting end 23b is the same as that of the second outer welding ring 1211.
  • Weld rings 1212 are of equal thickness.
  • the first connection bridge 22 is used to balance the solder on the first inner solder ring 1111 and the first outer solder ring 1112 . In other words, when there is too much solder on the first inner solder ring 1111, it can flow to the first outer solder ring 1112 through the first connection bridge 22; Can flow to the first inner weld ring 1111 via the first connecting bridge 22 .
  • the thicknesses of the first inner welding ring 1111 and the first outer welding ring 1112 are equal, so the first connecting bridge 22 between the first inner connecting end 22a and the first outer connecting end 22b can be a horizontal transition, Jagged transitions, wavy transitions, polyline transitions, stepped transitions, convex arc surface transitions, or concave arc surface transitions, etc.
  • the thicknesses of the first inner welding ring 1111 and the first outer welding ring 1112 may be different, so the first connecting bridge 22 between the first inner connecting end 22a and the first outer connecting end 22b may be a slope Flat transition, zigzag transition, wavy transition, polyline transition, stepped transition, convex arc transition, or concave arc transition, etc.
  • the material of the first connection bridge 22 may be the same as the material of the first inner weld ring 1111 (or the first outer weld ring 1112 ). In one embodiment, there are multiple first connecting bridges 22 , and the multiple first connecting bridges 22 are evenly distributed in the circumferential direction of the first inner welding ring 1111 and the first outer welding ring 1112 .
  • the second connection bridge 23 is used to balance the solder on the second inner solder ring 1211 and the second outer solder ring 1212 . In other words, when there is too much solder on the second inner solder ring 1211, it can flow to the second outer solder ring 1212 through the second connection bridge 23; It can flow to the second inner welding ring 1211 via the second connecting bridge 23 .
  • the thicknesses of the second inner welding ring 1211 and the second outer welding ring 1212 are equal, so the second connecting bridge 23 between the second inner connecting end 23a and the second outer connecting end 23b can be a horizontal transition, Jagged transitions, wavy transitions, polyline transitions, stepped transitions, convex arc surface transitions, or concave arc surface transitions, etc.
  • the thicknesses of the second inner welding ring 1211 and the second outer welding ring 1212 may be different, so the second connecting bridge 23 between the second inner connecting end 23a and the second outer connecting end 23b may be a slope Flat transition, zigzag transition, wavy transition, polyline transition, stepped transition, convex arc transition, or concave arc transition, etc.
  • the material of the second connection bridge 23 may be the same as the material of the second inner welding ring 1211 (or the second outer welding ring 1212 ). In one embodiment, there are multiple second connecting bridges 23 , and the multiple second connecting bridges 23 are evenly distributed in the circumferential direction of the second inner welding ring 1211 and the second outer welding ring 1212 .
  • first connection bridge 22 and the second connection bridge 23 in the MEMS sensor can be used alternatively.

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Abstract

一种MEMS传感器(1-5),包括：基板(11)与盖板(12)；基板包括MEMS结构(110)、围绕MEMS结构设置的第一焊接区(111)，以及保形地位于第一焊接区的第一焊接环(112)；盖板包括第二焊接区(121)，以及保形地位于第二焊接区的第二焊接环(122)；基板与盖板通过第一焊接环与第二焊接环焊接在一起形成密封结构(13)，以将MEMS结构限定在真空腔体(13a)内；第一焊接区与第二焊接区中的至少一个具有沿周向分布的环状凹槽(14)或环状凸起(15)。MEMS传感器的制作方法包括：提供预制作基板(11')与预制作盖板(12')，预制作基板包括MEMS结构(110)，与围绕MEMS结构设置的第一焊接区(111)；预制作盖板包括第二焊接区(121)；在第一焊接区保形地形成第一焊接环，在第二焊接区保形地形成第二焊接环(122)，在真空环境下将第一焊接环与第二焊接环焊接在一起，使基板与盖板形成密封结构(13)。MEMS传感器能获得更好的气密性。

Description

MEMS传感器及其制作方法 技术领域
本申请涉及半导体器件技术领域，尤其涉及一种MEMS传感器及其制作方法。
背景技术
气密性封装是MEMS领域常见的封装需求形式。MEMS器件如加速度传感器、压力传感器、角速度传感器等内部有可动部件，需要为可动部件提供气密性空腔，以保证可动部件在空腔内部有较小的阻尼和静摩擦力。MEMS器件如非制冷红外焦平面探测器内部有微测辐射热计，需要降低器件内部真空度，以保证较小的热辐射热量损耗。当空腔内部气压升高到真空度超过设定标准时，器件灵敏度将降低到标准值以下，造成器件失效。因此，气密封是决定器件寿命的关键性因素。
发明内容
有鉴于此，本申请公开了MEMS传感器及其制作方法。
本申请的第一方面提供一种MEMS传感器，包括：
基板，包括MEMS结构、围绕所述MEMS结构设置的第一焊接区，以及位于所述第一焊接区的第一焊接环；
盖板，包括第二焊接区，以及位于所述第二焊接区的第二焊接环；所述基板与所述盖板通过所述第一焊接环与所述第二焊接环焊接在一起形成密封结构，以将所述MEMS结构限定在真空腔体内；所述第一焊接区与所述第二焊接区中的至少一个具有沿周向分布的环状凹槽或环状凸起，所述第一焊接环保形地位于所述第一焊接区上，所述第二焊接环保形地位于所述第二焊接区上。
本申请的第二方面提供一种如上所述的MEMS传感器的制作方法，包括：
分别提供预制作基板与预制作盖板，所述预制作基板包括MEMS结构，与围绕所述MEMS结构设置的第一焊接区；所述预制作盖板包括第二焊接区；
在所述第一焊接区与所述第二焊接区中的至少一个上形成沿周向分布的环状凹槽或环状凸起；
在所述第一焊接区形成第一焊接环，以使所述预制作基板形成基板，所述第一焊接环保形地位于所述第一焊接区上；在所述第二焊接区形成第二焊接环，以使所述预制作盖板形成盖板，所述第二焊接环保形地位于所述第二焊接区上；
在真空环境下将所述第一焊接环与所述第二焊接环焊接在一起，使所述基板与所述盖板形成密封结构，以将所述MEMS结构限定在真空腔体内。
本申请的第三方面提供一种MEMS传感器，包括：
基板，包括MEMS结构，围绕所述MEMS结构设置的第一内焊接环、以及围绕所 述第一内焊接环设置的第一外焊接环；
盖板，包括第二内焊接环，与围绕所述第二内焊接环设置的第二外焊接环；所述基板与所述盖板通过所述第一内焊接环与所述第二内焊接环焊接在一起形成第一密封结构，所述第一密封结构将所述MEMS结构限定在真空腔体内；所述基板与所述盖板通过所述第一外焊接环与所述第二外焊接环焊接在一起形成第二密封结构，所述第二密封结构与所述第一密封结构之间形成真空夹层腔体。
附图说明
图1是本申请一实施例的MEMS传感器的截面结构示意图；
图2是去除第一焊接环的基板的俯视结构示意图；
图3是去除第二焊接环的盖板的仰视结构示意图；
图4是本申请一实施例的MEMS传感器的制作方法的流程图；
图5至图10是图4中的流程对应的中间结构示意图；
图11是本申请另一实施例的MEMS传感器的局部结构的截面结构示意图；
图12是本申请又一实施例的MEMS传感器的局部结构的截面结构示意图；
图13是本申请再一实施例的MEMS传感器的截面结构示意图；
图14是本申请另一实施例的MEMS传感器的截面结构示意图；
图15是本申请又一实施例的MEMS传感器的截面结构示意图；
图16是本申请再一实施例的MEMS传感器的截面结构示意图；
图17是本申请另一实施例的MEMS传感器的局部结构的截面结构示意图；
图18是本申请又一实施例的MEMS传感器的截面结构示意图；
图19是本申请再一实施例的MEMS传感器中的基板的俯视结构示意图；
图20是本申请再一实施例的MEMS传感器中的盖板的仰视结构示意图。
具体实施方式
为使本申请的上述目的、特征和优点能够更为明显易懂，下面结合附图对本申请的具体实施例做详细的说明。
图1是本申请一实施例的MEMS传感器的截面结构示意图。图2是去除第一焊接环的基板的俯视结构示意图；图3是去除第二焊接环的盖板的仰视结构示意图。
参照图1至图3所示，本实施例的MEMS传感器1包括：
基板11，包括MEMS结构110、围绕MEMS结构110设置的第一焊接区111，以及位于第一焊接区111的第一焊接环112；
盖板12，包括第二焊接区121，以及位于第二焊接区121的第二焊接环122；基板 11与盖板12通过第一焊接环112与第二焊接环122焊接在一起形成密封结构13，以将MEMS结构110限定在真空腔体13a内；第一焊接区111具有沿周向分布的环状凹槽14，第二焊接区121具有沿周向分布的环状凸起15，第一焊接环112保形地位于第一焊接区111上，第二焊接环122保形地位于第二焊接区121上。
基板11可以包括第一半导体衬底，MEMS结构110设置在第一半导体衬底上。MEMS结构110可根据MEMS传感器1的类型而定。例如MEMS传感器1为加速度传感器、压力传感器或角速度传感器时，MEMS结构110可包括固定电极与可动电极。可动电极可以为一端支撑的悬梁，或两端支撑的悬梁。又例如MEMS传感器1为非制冷红外焦平面探测器时，MEMS结构110包括上表面无覆盖的感光结构。本实施例对MEMS结构110不加以限定，仅需设置在真空环境即可。
本实施例中，参照图1与图2所示，第一焊接区111具有第一钝化层113。环状凹槽14位于第一钝化层113内。第一钝化层113的材料可以为氮化硅。其它实施例中，第一焊接区111可以具有第一介电层，环状凹槽14位于第一介电层内。第一介电层的材料可以为二氧化硅。或，第一焊接区111可以具有第一半导体层，环状凹槽14位于第一半导体层内。第一半导体层的材料可以为掺杂多晶硅，也可以为单晶硅衬底。或，环状凹槽14位于第一介电层、第一钝化层以及第一半导体层中的至少两层的叠层结构内。本实施例不限定第一焊接区111的材料种类。
盖板12可以包括第二半导体衬底。
本实施例中，参照图1与图3所示，第二焊接区121具有第二介电层123。环状凸起15位于第二介电层123上。环状凸起15和第二介电层123的材料可以为二氧化硅。其它实施例中，第二焊接区121可以具有第二钝化层，环状凸起15位于第二钝化层上。环状凸起15和第二钝化层的材料可以为氮化硅。或，第二焊接区121可以具有第二半导体层，环状凸起15位于第二半导体层上。环状凸起15和第二半导体层的材料可以为掺杂多晶硅，也可以为单晶硅衬底。或，第二焊接区121可以具有第二介电层、第二钝化层以及第二半导体层中的至少两层的叠层结构，环状凸起15位于叠层结构上。环状凸起15的材料与上述叠层结构中与环状凸起15相接的层的材料一样，或者，环状凸起15也为与第二焊接区121内的叠层结构一样的叠层结构。本实施例不限定第二焊接区121的材料种类。
第一焊接环112与第二焊接环122的材料为金属，例如铜或铝。第一焊接环112保形地位于第一焊接区111上是指：第一焊接环112的厚度较薄，第一焊接环112远离第一焊接区111的表面围合的环状凹陷区沿垂直周向的剖面与环状凹槽14沿垂直周向的剖面的形状一致。
换言之，当环状凹槽14沿垂直周向的剖面为三角形时，第一焊接环112远离第一焊接区111的表面围合的环状凹陷区沿垂直周向的剖面为三角形。当环状凹槽14沿垂直周向的剖面为正方形时，第一焊接环112远离第一焊接区111的表面围合的环状凹陷区沿垂直周向的剖面为正方形。当环状凹槽14沿垂直周向的剖面为长方形时，第一焊接环112远离第一焊接区111的表面围合的环状凹陷区沿垂直周向的剖面为长方形(参照图1所示)。当环状凹槽14沿垂直周向的剖面为正梯形时，第一焊接环112远离第一 焊接区111的表面围合的环状凹陷区沿垂直周向的剖面为正梯形。当环状凹槽14沿垂直周向的剖面为倒梯形时，第一焊接环112远离第一焊接区111的表面围合的环状凹陷区沿垂直周向的剖面为倒梯形。
第二焊接环122保形地位于第二焊接区121上是指：第二焊接环122的厚度较薄，第二焊接环122远离第二焊接区121的表面形成的环状凸起区沿垂直周向的剖面与环状凸起15沿垂直周向的剖面形状一致。
换言之，当环状凸起15沿垂直周向的剖面为三角形时，第二焊接环122远离第二焊接区121的表面形成的环状凸起区沿垂直周向的剖面为三角形。当环状凸起15沿垂直周向的剖面为正方形时，第二焊接环122远离第二焊接区121的表面形成的环状凸起区沿垂直周向的剖面为正方形。当环状凸起15沿垂直周向的剖面为长方形时，第二焊接环122远离第二焊接区121的表面形成的环状凸起区沿垂直周向的剖面为长方形(参照图1所示)。当环状凸起15沿垂直周向的剖面为正梯形时，第二焊接环122远离第二焊接区121的表面形成的环状凸起区沿垂直周向的剖面为正梯形。当环状凸起15沿垂直周向的剖面为倒梯形时，第二焊接环122远离第二焊接区121的表面形成的环状凸起区沿垂直周向的剖面为倒梯形。
参照图1所示，环状凹槽14与环状凸起15可使第一焊接环112与第二焊接环122相啮合。焊料层(未图示)的形状与尺寸匹配于第一焊接环112与第二焊接环122的啮合面。第一焊接环112与第二焊接环122通过焊料焊接后，一则，在相同焊接环宽度情况下，相对于第一焊接环112与第二焊接环122的焊接面都为平面的方案，本方案可制造凹凸不平结构，好处在于：可增加外界气体进入真空腔室13a的泄漏通道的有效长度，从而可以降低气体的漏率，提高MEMS传感器1的可靠性和寿命。尤其针对红外探测器，MEMS结构110接收目标红外辐射后的温度变化很微弱，为了尽量避免空气对流造成的桥面热损失，真空腔室13a内的真空度要求在E-3Torr以下。通过第一焊接环112与第二焊接环122的凹凸不平结构，降低了真空腔室13a的封装漏率、腔室内的真空度维持时间变长，直接保证了红外探测器的可靠性。
二则，第一焊接环112与第二焊接环122的焊接面为非平面的凹凸不平结构，可提高MEMS传感器1的剪切强度，从而提高抗冲击可靠性。
三则，对于抗震性能要求高的MEMS结构110，环状凹槽14与环状凸起15使厚度较薄的第一焊接环112与第二焊接环122相啮合，可进一步提高MEMS传感器1的剪切强度，从而提高抗冲击可靠性。
为进一步增大气体泄漏通道的长度，参照图1所示，环状凹槽14的深度D与环状凹槽14的宽度W1之间的比值大于1/10；环状凸起15的高度H与环状凸起15的宽度W2之间的比值大于1/10。
一些实施例中，第一焊接环112与第二焊接环122通过铟基焊料焊接在一起。一些实施例中，也可以采用锡基焊料焊接。在MEMS传感器1的某些使用环境中，例如高温下，锡膏焊料中的有机助焊剂会挥发释放气体，导致真空腔体13a内的压强增大。相对于锡膏焊料，铟基焊料或锡基焊料由于无有机助焊剂，因而在高温下不会释放气体，不会影响真空腔体13a内的真空度。铟基焊料与锡基焊料分别是以铟、锡为主要成分， 掺杂金、银、铜等其它金属的合金。铟基焊料例如为In97Ag3或In95Ag5。
本申请一实施例还提供了图1至图3中的MEMS传感器的制作方法。图4是制作方法的流程图。图5至图10是图4中的流程对应的中间结构示意图。
首先，参照图4中的步骤S1、图5与图6所示，分别提供预制作基板11'与预制作盖板12'，预制作基板11'包括MEMS结构110，与围绕MEMS结构110设置的第一焊接区111；预制作盖板12'包括第二焊接区121。
预制作基板11'可以包括第一半导体衬底，MEMS结构110设置在第一半导体衬底上。MEMS结构110可根据MEMS传感器1的类型而定。例如MEMS传感器1为加速度传感器、压力传感器或角速度传感器时，MEMS结构110可包括固定电极与可动电极。可动电极可以为一端支撑的悬梁，或两端支撑的悬梁。又例如MEMS传感器1为非制冷红外焦平面探测器时，MEMS结构110包括上表面无覆盖的感光结构。本实施例对MEMS结构110不加以限定，仅需设置在真空环境即可。
本实施例中，参照图5所示，第一焊接区111具有第一钝化层113。第一钝化层113的材料可以为氮化硅。其它实施例中，第一焊接区111可以具有第一介电层或第一半导体层。第一介电层的材料可以为二氧化硅。第一半导体层的材料可以为掺杂多晶硅，也可以为单晶硅衬底。或第一焊接区111具有包括第一介电层、第一钝化层以及第一半导体层中的至少两层的叠层结构。本实施例不限定第一焊接区111的材料种类。
预制作盖板12'可以包括第二半导体衬底。
本实施例中，参照图6所示，第二焊接区121具有第二介电层123。第二介电层123的材料可以为二氧化硅。其它实施例中，第二焊接区121可以具有第二钝化层或第二半导体层。第二钝化层的材料可以为氮化硅。第二半导体层的材料可以为掺杂多晶硅，也可以为单晶硅衬底。或，第二焊接区121具有包括第二介电层、第二钝化层以及第二半导体层中的至少两层的叠层结构。本实施例不限定第二焊接区121的材料种类。
接着，参照图4中的步骤S2、图7与图8所示，在第一焊接区111形成沿周向分布的环状凹槽14；在第二焊接区121形成沿周向分布的环状凸起15。
环状凹槽14与环状凸起15可以采用干法刻蚀实现。在一实施例中，步骤S2可以包括：
步骤S21，在预制作基板11'与预制作盖板12'上分别形成光刻胶层；后采用对应掩模版对该光刻胶层进行曝光；通过显影，形成各自的图形化的光刻胶层。
步骤S22，以对应的图形化的光刻胶层为掩膜，干法刻蚀第一钝化层113，以在第一钝化层113内形成环状凹槽14；以对应的图形化的光刻胶层为掩膜，干法刻蚀第二介电层123，以在第二介电层123内形成环状凸起15。
步骤S23，灰化去除剩余的光刻胶层。
再接着，参照图4中的步骤S3、图9与图10所示，在第一焊接区111形成第一焊接环112，以使预制作基板11'形成基板11，第一焊接环112保形地位于第一焊接区111上；在第二焊接区121形成第二焊接环122，以使预制作盖板12'形成盖板12，第二焊 接环122保形地位于第二焊接区121上。
第一焊接环112与第二焊接环122的材料为金属，例如铜或铝。第一焊接环112可以通过电子束蒸发或者溅射工艺形成。第二焊接环122也可以通过电子束蒸发或者溅射工艺形成。
电子束蒸发或者溅射工艺可以整面形成金属层，第一焊接区111与第二焊接区121之外区域的金属层可通过干法刻蚀工艺或湿法刻蚀工艺去除。
金属层的厚度较薄，对于基板11，金属层的厚度满足：金属层远离第一焊接区111的表面围合的环状凹陷区沿垂直周向的剖面与环状凹槽14沿垂直周向的剖面形状一致。对于盖板12，金属层的厚度满足：金属层远离第二焊接区121的表面围合的环状凸起区沿垂直周向的剖面与环状凸起15沿垂直周向的剖面形状一致。
电子束蒸发或者溅射工艺形成金属层前，可将预制作基板11'与预制作盖板12'浸泡在有机溶剂中超声波震荡，以清洗残留物。有机溶剂可以为丙酮、乙醇、乙醚、异丙醇中的至少一种。
之后，参照图4中的步骤S4与图1所示，将第一焊接环112与第二焊接环122焊接在一起，使基板11与盖板12形成密封结构13，以将MEMS结构110限定在真空腔体13a内。
本步骤在真空环境下焊接。在一实施例中，可使用真空键合机进行焊接。在真空键合机内，焊料达到熔点开始融化，焊料在第一焊接环112与第二焊接环122上快速铺展、充盈凹凸不平结构，降温后焊料凝固与第一焊接环112、第二焊接环122形成在径向上延伸的链状啮齿结构。
在一实施例中，第一焊接环112与第二焊接环122通过铟基焊料焊接在一起。一些实施例中，也可以采用锡基焊料焊接。相对于锡膏焊料，铟基焊料与锡基焊料由于无有机助焊剂，因而在高温下不会释放气体，不会影响真空腔体13a内的真空度。
图11是本申请另一实施例的MEMS传感器的局部结构的截面结构示意图。参照图11所示，本实施例的MEMS传感器2及其制作方法与上述实施例的MEMS传感器1及其制作方法大致相同，区别在于：环状凹槽14与环状凸起15包括两圈。
环状凹槽14与环状凸起15的圈数一致。本实施例中，各圈环状凹槽14的尺寸相同，上述尺寸包括宽度与深度；各圈环状凸起15的尺寸也相同，上述尺寸包括宽度与高度。其它实施例中，各圈环状凹槽14的尺寸也可以不同，例如宽度和/或深度不同；各圈环状凸起15的尺寸也可以不相同，例如宽度和/或高度不同，对应的凹槽和凸起尺寸匹配即可。
在一些实施例中，可以是凸起和凸起对应，凹陷和凹陷对应。
其它实施例中，环状凹槽14与环状凸起15还可以包括两圈以上。
环状凹槽14与环状凸起15的数目越多，越能增加气体泄漏通道的有效长度。
图12是本申请又一实施例的MEMS传感器的局部结构的截面结构示意图。参照图12所示，本实施例的MEMS传感器3及其制作方法与上述实施例的MEMS传感器1、 2及其制作方法大致相同，区别在于：第一焊接环112朝向盖板12方向依次包括：第一粘附层112a、第一阻挡层112b以及第一润湿层112c；第二焊接环122朝向基板11方向依次包括：第二粘附层122a、第二阻挡层122b以及第二润湿层122c。
本实施例中，第一粘附层112a选择与第一焊接区内设置的材料层，例如第一钝化层113或第一介电层或第一半导体层，的粘附性好、热膨胀系数匹配的金属，上述金属例如为钛或铬。第一阻挡层112b选择与第一润湿层112c、第一粘附层112a两层粘附性好，热膨胀系数介于两层之间，焊接性能居中的金属，上述金属例如为镍。第一润湿层112c同时也是防氧化层，选择性能稳定、润湿性好、难氧化、钎焊性能好的金属，上述金属例如为金。第二粘附层122a选择与第二焊接区内设置的材料层，例如第二介电层123或第二钝化层或第二半导体层，的粘附性好、热膨胀系数匹配的金属，上述金属例如为钛或铬。第二阻挡层122b选择与第二润湿层122c、第二粘附层122a两层粘附性好，热膨胀系数介于两层之间，焊接性能居中的金属，上述金属例如为镍。第二润湿层122c同时也是防氧化层，选择性能稳定、润湿性好、难氧化、钎焊性能好的金属，上述金属例如为金。
其它实施例中，可以仅第一焊接环112朝向盖板12方向依次包括：第一粘附层112a、第一阻挡层112b以及第一润湿层121c；或仅第二焊接环122朝向基板11方向依次包括：第二粘附层122a、第二阻挡层122b以及第二润湿层122c。
在焊接过程中，焊料达到熔点开始融化，焊料在第一焊接环112和/或第二焊接环122的润湿层快速铺展、充盈凹凸不平结构，降温后焊料凝固与第一焊接环112、第二焊接环122形成在径向上延伸的链状啮齿结构。
图13是本申请又一实施例的MEMS传感器的截面结构示意图。参照图13所示，本实施例的MEMS传感器4及其制作方法与上述实施例的MEMS传感器1、2、3及其制作方法大致相同，区别在于：第一焊接区111具有沿周向分布的环状凸起15，第二焊接区121具有沿周向分布的环状凹槽14。
参照图13所示，环状凸起15与环状凹槽14可使第一焊接环112与第二焊接环122相啮合。
图14是本申请再一实施例的MEMS传感器的截面结构示意图。参照图14所示，本实施例的MEMS传感器5及其制作方法与上述实施例的MEMS传感器1、2、3、4及其制作方法大致相同，区别在于：第一焊接区111具有沿周向分布的环状凹槽14，第二焊接区121为平面。
第一焊接环112保形地位于第一焊接区111上，因而，第一焊接环112远离第一焊接区111的表面围合一环状凹陷区，且该环状凹陷区沿垂直周向的剖面与环状凹槽14沿垂直周向的剖面形状一致。第二焊接环122保形地位于第二焊接区121上，因而，第二焊接环122远离第二焊接区121的表面为平面。
参照图14所示，焊料层16包括相对的第一表面与第二表面，第一表面的形状与尺寸匹配于第一焊接环112的形状与尺寸，第二表面的形状与尺寸匹配于第二焊接环122的形状与尺寸。
其它实施例中，也可以第一焊接区111具有沿周向分布的环状凸起15，第二焊接区121为平面；或第一焊接区111为平面，第二焊接区121具有沿周向分布的环状凹槽14；或第一焊接区111为平面，第二焊接区121具有沿周向分布的环状凸起15。
图15是本申请另一实施例的MEMS传感器的截面结构示意图，对应部分可参照上述实施例，故相关部分不再详述。
参照图15所示，本实施例的MEMS传感器6包括：
基板11，包括MEMS结构110，围绕MEMS结构110设置的第一内焊接环1111、以及围绕第一内焊接环1111设置的第一外焊接环1112；
盖板12，包括第二内焊接环1211，与围绕第二内焊接环1211设置的第二外焊接环1212；基板11与盖板12通过第一内焊接环1111与第二内焊接环1211焊接在一起形成第一密封结构17，第一密封结构17将MEMS结构110限定在真空腔体17a内；基板11与盖板12通过第一外焊接环1112与第二外焊接环1212焊接在一起形成第二密封结构18，第二密封结构18与第一密封结构17之间形成真空夹层腔体18a。
第一内焊接环1111与第一外焊接环1112的材料为金属，例如铜或铝。第一内焊接环1111与第一外焊接环1112可与MEMS结构110中的金属层位于同层。三者可以在同一工序中制作，也可以分开制作。
盖板12可以包括第二半导体衬底。第二内焊接环1211与第二外焊接环1212的材料为金属，例如铜或铝。
在一实施例中，第一内焊接环1111与第二内焊接环1211的截面尺寸一致，第一外焊接环1112与第二外焊接环1212的截面尺寸一致，以使得焊接可以完全对准，提高焊接效果。
第一内焊接环1111与第二内焊接环1211的焊接、第一外焊接环1112与第二外焊接环1212的焊接可采用铟基焊料或锡基焊料实现。铟基焊料与锡基焊料分别是以铟、锡为主要成分，掺杂金、银、铜等其它金属的合金。铟基焊料例如为In97Ag3或In95Ag5。
本实施例中，第一内焊接环1111与第二内焊接环1211的焊接、第一外焊接环1112与第二外焊接环1212的焊接在同一真空环境中进行，以使得MEMS传感器1出厂时，真空夹层腔体18a内的压强与真空腔体17a内的压强相等，即真空夹层腔体18a内的初始压强与真空腔体17a内的初始压强相等。
第一内焊接环1111与第一外焊接环1112的厚度(焊接环顶部与基板的垂直距离)可以相等或不等，第二内焊接环1211与第二外焊接环1212的厚度(焊接环顶部与盖板的垂直距离)可以相等或不等。第一内焊接环1111与第二内焊接环1211的厚度之和与第一外焊接环1112与第二外焊接环1212的厚度之和相等。
其它实施例中，第一内焊接环1111与第二内焊接环1211的焊接可以在第一真空环境中进行，第一外焊接环1112与第二外焊接环1212的焊接在第二真空环境中进行，第二真空环境的压强小于或远小于外界环境压强，且大于或略大于第一真空环境的压强。外界环境压强一般为一大气压。从而，使得真空夹层腔体18a内的初始压强大于或略大于真空腔体17a内的初始压强，但小于或远小于外界环境压强。
其他实施例中，也可以将所述真空夹层腔体内的初始压强与所述真空腔体内的初始压强之间的压强差控制在预定范围内，不论真空夹层腔体内的初始压强与所述真空腔体内的初始压强哪个大，只要两者的差值在该预定范围内且远小于外界环境压强即可。制备时，可以通过控制真空夹层腔体中吸气剂的量和真空腔体中吸气剂的量来实现两者的压强差在预定范围内，这里预定范围内可以是E-3Torr以内或者其他可以实现真空腔体中器件正常工作的值。
外界环境中的气体泄漏进入真空腔体17a包括：第一步，外界环境中的气体泄漏进入真空夹层腔体18a；第二步，真空夹层腔体18a中的气体泄漏进入真空腔体17a。
一则，上述两步泄漏均需时间，可延长MEMS传感器1达到失效的时间。
二则，即使第一步泄漏导致真空夹层腔体18a内的压强上升，由于真空夹层腔体18a内的初始压强较小，因而上升幅度有限。
三则，研究表明，基于分子流模型，密封结构内外的压强差越小，单位时间泄漏进压强较小的腔体内的气体的物质的量越小，即气体漏率越小。由于真空夹层腔体18a内的压强上升幅度有限，真空腔体17a与真空夹层腔体18a之间的压强差仍然较小，气体泄漏进入真空腔体17a内的速度慢，从而可以降低气体的漏率，提高MEMS传感器1的可靠性和寿命。
一些实施例中，第一内焊接环1111与第一外焊接环1112之间的间距L与第一内焊接环1111(或第一外焊接环1112)的宽度W的比值范围为：0.1～0.3(包括端点值)，以减小真空夹层腔体18a的宽度，提高基板11的表面利用率。
图16是本申请又一实施例的MEMS传感器的截面结构示意图。参照图16所示，本实施例的MEMS传感器7与上一实施例的MEMS传感器6大致相同，区别在于：基板11和盖板12围合真空腔体17a的部分设置有第一吸气层20，基板11和盖板12围合真空夹层腔体18a的部分设置有第二吸气层21。在一些实施例中，MEMS传感器上不设置吸气层20。
第一吸气层20和第二吸气层21用于吸收气体，对应降低真空腔体17a内的真空度和真空夹层腔体18a内的真空度。
本实施例中，第一吸气层20与第二吸气层21在第一内焊接环1111与第二内焊接环1211、以及第一外焊接环1112与第二外焊接环1212的焊接前进行激活。激活可通过加热第一吸气层20与第二吸气层21实现。
第一吸气层20和/或第二吸气层21的材料可以包括锆或钛。
其它实施例中，第一吸气层20可以仅设置在基板11围合真空腔体17a的部分，或仅设置在盖板12位围合真空腔体17a的部分。第二吸气层21可以仅设置在基板11围合真空夹层腔体18a的部分，或仅设置在盖板12围合真空夹层腔体18a的部分。
对于仅设置第一吸气层20的MEMS传感器，第一吸气层20可在第一内焊接环1111与第二内焊接环1211、以及第一外焊接环1112与第二外焊接环1212的焊接后进行激活。在第一内焊接环1111与第二内焊接环1211、以及第一外焊接环1112与第二外焊接环1212在同一真空环境中焊接的情况下，真空腔体17a与真空夹层腔体18a的压强相等。 此时，激活第一吸气层20，第一吸气层20吸附真空腔体17a内的气体，可降低真空腔体17a的初始压强，从而实现真空夹层腔体18a的初始压强略大于真空腔体17a的初始压强。上述焊接时的环境压强，即真空夹层腔体18a的初始压强，远小于外界环境压强。激活可通过加热第一吸气层20实现。
一些实施例中，当MEMS结构110包括感光结构时，感光结构对应盖板的感光区域，盖板的其余区域为非感光区域。第一吸气层20若会降低光透过率，则将其设置于非感光区域。
一些实施例中，基板11和/或盖板12还包括放气材料层，例如MEMS传感器7的电路结构。该电路结构在图形化工艺中使用光刻胶做掩膜层，光刻胶在去除工艺中可能存在残留，保留在电路结构中；该残留的光刻胶在MEMS传感器7的某些使用环境中，例如高温下会释放气体，因而，该残留的光刻胶为放气材料层。在一些实施例中，相对于设置在真空腔体17a内，放气材料层设置在真空夹层腔体18a内。
图17是本申请另一实施例的MEMS传感器的局部结构的截面结构示意图。参照图17所示，本实施例的MEMS传感器8与前述实施例的MEMS传感器6、7大致相同，区别在于：第一内焊接环1111和第一外焊接环1112朝向盖板12方向依次包括：第一粘附层11a、第一阻挡层11b以及第一润湿层11c；第二内焊接环1211和第二外焊接环1212朝向基板11方向依次包括：第二粘附层12a、第二阻挡层12b以及第二润湿层12c。
本实施例中，第一粘附层11a选择与基板11，例如第一半导体衬底，的粘附性好、热膨胀系数匹配的金属，上述金属例如包括钛或铬。第一阻挡层11b选择与第一润湿层11c、第一粘附层11a两层粘附性好，热膨胀系数介于两层之间，焊接性能居中的金属，上述金属例如包括镍。第一润湿层11c同时也是防氧化层，选择性能稳定、润湿性好、难氧化、钎焊性能好的金属，上述金属例如包括金。第二粘附层12a选择与盖板12，例如第二半导体衬底，的粘附性好、热膨胀系数匹配的金属，上述金属例如包括钛或铬。第二阻挡层12b选择与第二润湿层12c、第二粘附层12a两层粘附性好，热膨胀系数介于两层之间，焊接性能居中的金属，上述金属例如包括镍。第二润湿层12c同时也是防氧化层，选择性能稳定、润湿性好、难氧化、钎焊性能好的金属，上述金属例如包括金。
其它实施例中，可以仅第一内焊接环1111朝向盖板12方向依次包括：第一粘附层11a、第一阻挡层11b以及第一润湿层11c；或仅第一外焊接环1112朝向盖板12方向依次包括：第一粘附层11a、第一阻挡层11b以及第一润湿层11c；或仅第二内焊接环1211朝向基板11方向依次包括：第二粘附层12a、第二阻挡层12b以及第二润湿层12c；或仅第二外焊接环1212朝向基板11方向依次包括：第二粘附层12a、第二阻挡层12b以及第二润湿层12c。
图18是本申请再一实施例的MEMS传感器的截面结构示意图。参照图18所示，本实施例的MEMS传感器9与前述实施例的MEMS传感器6、7、8大致相同，区别在于：基板11还包括第一中间焊接环1113，第一中间焊接环1113设置在第一内焊接环1111与第一外焊接环1112之间；盖板12还包括第二中间焊接环1213，第二中间焊接环1213设置在第二内焊接环1211与第二外焊接环1212之间；基板11与盖板12通过 第一中间焊接环1113与第二中间焊接环1213焊接在一起形成第三密封结构19，第三密封结构19与第一密封结构17之间形成第一真空夹层腔体19a，第三密封结构19与第二密封结构18之间形成第二真空夹层腔体19b。
在一实施例中，第一真空夹层腔体19a内的初始压强、第二真空夹层腔体19b内的初始压强都与真空腔体17a内的初始压强相等。
本实施例中，外界环境中的气体泄漏进入真空腔体17a包括：第一步，外界环境中的气体泄漏进入第二真空夹层腔体19b；第二步，第二真空夹层腔体19b中的气体泄漏进入第一真空夹层腔体19a；第三步，第一真空夹层腔体19a中的气体泄漏进入真空腔体17a。本实施例的MEMS传感器9可进一步降低气体的漏率，提高可靠性和寿命。
其它实施例中，第一密封结构17与第二密封结构18之间可以设置有两个及以上的中间密封结构，以进一步降低气体的漏率。
图19是本申请又一实施例的MEMS传感器中的基板的俯视结构示意图。图20是本申请又一实施例的MEMS传感器中的盖板的仰视结构示意图。参照图19与图20所示，本实施例的MEMS传感器与前述实施例的MEMS传感器6、7、8、9大致相同，区别在于：第一内焊接环1111与第一外焊接环1112之间设置有第一连接桥22，第一连接桥22包括第一内连接端22a与第一外连接端22b，第一内连接端22a连接于第一内焊接环1111，第一外连接端22b连接于第一外焊接环1112，第一内连接端22a的厚度与第一内焊接环1111的厚度相等，第一外连接端22b的厚度与第一外焊接环1112的厚度相等；第二内焊接环1211与第二外焊接环1212之间设置有第二连接桥23，第二连接桥23包括第二内连接端23a与第二外连接端23b，第二内连接端23a连接于第二内焊接环1211，第二外连接端23b连接于第二外焊接环1212，第二内连接端23a的厚度与第二内焊接环1211的厚度相等，第二外连接端23b的厚度与第二外焊接环1212的厚度相等。
第一连接桥22用于平衡第一内焊接环1111与第一外焊接环1112上的焊料。换言之，第一内焊接环1111上的焊料过多的情况下，可经第一连接桥22流动至第一外焊接环1112；反之，第一外焊接环1112上的焊料过多的情况下，可经第一连接桥22流动至第一内焊接环1111。
本实施例中，第一内焊接环1111与第一外焊接环1112的厚度相等，因而，第一内连接端22a与第一外连接端22b之间的第一连接桥22可为水平过渡、锯齿状过渡、波浪状过渡、折线状过渡、台阶状过渡、上凸的弧面过渡、或下凹的弧面过渡等。
其它实施例中，第一内焊接环1111与第一外焊接环1112的厚度可以不等，因而，第一内连接端22a与第一外连接端22b之间的第一连接桥22可为斜坡状平面过渡、锯齿状过渡、波浪状过渡、折线状过渡、台阶状过渡、上凸的弧面过渡、或下凹的弧面过渡等。
第一连接桥22的材料可以与第一内焊接环1111(或第一外焊接环1112)的材料相同。在一实施例中，第一连接桥22有多个，多个第一连接桥22在第一内焊接环1111和第一外焊接环1112的周向上均匀分布。
第二连接桥23用于平衡第二内焊接环1211与第二外焊接环1212上的焊料。换 言之，第二内焊接环1211上的焊料过多的情况下，可经第二连接桥23流动至第二外焊接环1212；反之，第二外焊接环1212上的焊料过多的情况下，可经第二连接桥23流动至第二内焊接环1211。
本实施例中，第二内焊接环1211与第二外焊接环1212的厚度相等，因而，第二内连接端23a与第二外连接端23b之间的第二连接桥23可为水平过渡、锯齿状过渡、波浪状过渡、折线状过渡、台阶状过渡、上凸的弧面过渡、或下凹的弧面过渡等。
其它实施例中，第二内焊接环1211与第二外焊接环1212的厚度可以不等，因而，第二内连接端23a与第二外连接端23b之间的第二连接桥23可为斜坡状平面过渡、锯齿状过渡、波浪状过渡、折线状过渡、台阶状过渡、上凸的弧面过渡、或下凹的弧面过渡等。
第二连接桥23的材料可以与第二内焊接环1211(或第二外焊接环1212)的材料相同。在一实施例中，第二连接桥23有多个，多个第二连接桥23在第二内焊接环1211和第二外焊接环1212的周向上均匀分布。
其它实施例中，MEMS传感器中的第一连接桥22与第二连接桥23可以择一使用。
需要说明的是，在不冲突的情况下，各实施例可以组合，例如，图1所示实施例可以与图15所示实施例组合等，在此不再赘述。
虽然本申请披露如上，但本申请并非限定于此。任何本领域技术人员，在不脱离本申请的精神和范围内，均可作各种更动与修改，因此本申请的保护范围应当以权利要求所限定的范围为准。

Claims (20)

  1. 一种MEMS传感器(1-5)，包括：
    基板(11)，包括MEMS结构(110)、围绕所述MEMS结构设置的第一焊接区(111)，以及位于所述第一焊接区的第一焊接环(112)；
    盖板(12)，包括第二焊接区(121)，以及位于所述第二焊接区的第二焊接环(122)；所述基板与所述盖板通过所述第一焊接环与所述第二焊接环焊接在一起形成密封结构(13)，以将所述MEMS结构限定在真空腔体(13a)内；所述第一焊接区与所述第二焊接区中的至少一个具有沿周向分布的环状凹槽(14)或环状凸起(15)，所述第一焊接环保形地位于所述第一焊接区上，所述第二焊接环保形地位于所述第二焊接区上。
  2. 根据权利要求1所述的MEMS传感器，其中，
    所述第一焊接区具有沿周向分布的环状凹槽，所述第二焊接区具有沿周向分布的环状凸起，所述环状凹槽与所述环状凸起使所述第一焊接环与所述第二焊接环相啮合；或
    所述第一焊接区具有沿周向分布的环状凸起，所述第二焊接区具有沿周向分布的环状凹槽，所述环状凸起与所述环状凹槽使所述第一焊接环与所述第二焊接环相啮合；或
    所述第一焊接区具有沿周向分布的环状凹槽或环状凸起，所述第二焊接区为平面；或
    所述第一焊接区为平面，所述第二焊接区具有沿周向分布的环状凹槽或环状凸起。
  3. 根据权利要求1或2所述的MEMS传感器，其中，所述环状凹槽或所述环状凸起包括两圈或两圈以上，各圈所述环状凹槽或各圈所述环状凸起的尺寸相同或不同。
  4. 根据前述任一权利要求所述的MEMS传感器，其中，所述环状凹槽或所述环状凸起沿垂直所述周向的剖面为三角形、正方形、长方形、正梯形或倒梯形。
  5. 根据前述任一权利要求所述的MEMS传感器，其中，所述环状凹槽的深度与所述环状凹槽的宽度之间的比值大于1/10；或所述环状凸起的高度与所述环状凸起的宽度之间的比值大于1/10。
  6. 根据前述任一权利要求所述的MEMS传感器，其中，所述第一焊接环朝向所述盖板方向依次包括：第一粘附层(112a)、第一阻挡层(112b)以及第一润湿层(112c)；和/或所述第二焊接环朝向所述基板方向依次包括：第二粘附层(122a)、第二阻挡层(122b)以及第二润湿层(122c)。
  7. 根据前述任一权利要求所述的MEMS传感器，其中，
    所述第一焊接区具有第一介电层、第一钝化层(113)或第一半导体层中的至少一层，其中，所述环状凹槽位于所述第一介电层、所述第一钝化层或所述第一半导体层内，或所述环状凸起与所述第一介电层、所述第一钝化层或所述第一半导体层材质相同；或
    所述第二焊接区具有第二介电层(123)、第二钝化层或第二半导体层中的至少一层，其中，所述环状凹槽位于所述第二介电层、所述第二钝化层或所述第二半导体层内，或所述环状凸起与所述第二介电层、所述第二钝化层或所述第二半导体层材质相同。
  8. 根据前述任一权利要求所述的MEMS传感器，其中，所述第一焊接环与所述第二焊接环通过铟基焊料或锡基焊料焊接在一起。
  9. 一种如权利要求1所述的MEMS传感器(1-5)的制作方法，包括：
    分别提供预制作基板(11')与预制作盖板(12')，所述预制作基板包括MEMS结构(110)，与围绕所述MEMS结构设置的第一焊接区(111)；所述预制作盖板包括第二 焊接区(121)；
    在所述第一焊接区与所述第二焊接区中的至少一个上形成沿周向分布的环状凹槽(14)或环状凸起(15)；
    在所述第一焊接区形成第一焊接环(112)，以使所述预制作基板形成基板(11)，所述第一焊接环保形地位于所述第一焊接区上；在所述第二焊接区形成第二焊接环(122)，以使所述预制作盖板形成盖板(12)，所述第二焊接环保形地位于所述第二焊接区上；
    在真空环境下将所述第一焊接环与所述第二焊接环焊接在一起，使所述基板与所述盖板形成密封结构(13)，以将所述MEMS结构限定在真空腔体(13a)内。
  10. 根据权利要求9所述的MEMS传感器的制作方法，其中，
    所述第一焊接区具有沿周向分布的环状凹槽，所述第二焊接区具有沿周向分布的环状凸起，所述环状凹槽与所述环状凸起使所述第一焊接环与所述第二焊接环相啮合；或
    所述第一焊接区具有沿周向分布的环状凸起，所述第二焊接区具有沿周向分布的环状凹槽，所述环状凸起与所述环状凹槽使所述第一焊接环与所述第二焊接环相啮合；或
    所述第一焊接区具有沿周向分布的环状凹槽或环状凸起，所述第二焊接区为平面；或
    所述第一焊接区为平面，所述第二焊接区具有沿周向分布的环状凹槽或环状凸起。
  11. 根据权利要求9或10所述的MEMS传感器的制作方法，其中，
    所述第一焊接区具有第一介电层、第一钝化层(113)或第一半导体层中的至少一层，所述环状凹槽或所述环状凸起通过刻蚀所述第一介电层、所述第一钝化层或所述第一半导体层形成；或
    所述第二焊接区具有第二介电层(123)、第二钝化层或第二半导体层中的至少一层，所述环状凹槽或所述环状凸起通过刻蚀所述第二介电层、所述第二钝化层或所述第二半导体层形成。
  12. 根据前述任一权利要求所述的MEMS传感器的制作方法，其中，所述第一焊接环与所述第二焊接环通过铟基焊料或锡基焊料焊接在一起。
  13. 一种MEMS传感器(6-9)，包括：
    基板(11)，包括MEMS结构(110)，围绕所述MEMS结构设置的第一内焊接环(1111)、以及围绕所述第一内焊接环设置的第一外焊接环(1112)；
    盖板(12)，包括第二内焊接环(1211)，与围绕所述第二内焊接环设置的第二外焊接环(1212)；所述基板与所述盖板通过所述第一内焊接环与所述第二内焊接环焊接在一起形成第一密封结构(17)，所述第一密封结构将所述MEMS结构限定在真空腔体(17a)内；所述基板与所述盖板通过所述第一外焊接环与所述第二外焊接环焊接在一起形成第二密封结构(18)，所述第二密封结构与所述第一密封结构之间形成真空夹层腔体(18a)。
  14. 根据权利要求13所述的MEMS传感器，其中，
    所述真空夹层腔体内的初始压强与所述真空腔体内的初始压强相等，或
    所述真空夹层腔体内的初始压强大于所述真空腔体内的初始压强，或
    所述真空夹层腔体内的初始压强与所述真空腔体内的初始压强之间的压强差在预定范围内。
  15. 根据权利要求13所述的MEMS传感器，其中，所述基板至少还包括第一中间焊接环(1113)，所述第一中间焊接环设置在所述第一内焊接环与所述第一外焊接环之间；所述盖板至少还包括第二中间焊接环(1213)，所述第二中间焊接环设置在所述第二内焊接环与所述第二外焊接环之间；所述基板与所述盖板通过所述第一中间焊接环与所述第二中间焊接环焊接在一起形成第三密封结构(19)，所述第三密封结构与所述第一密封结构之间形成第一真空夹层腔体(19a)，所述第三密封结构与所述第二密封结构之间形成第二真空夹层腔体(19b)。
  16. 根据权利要求13或14所述的MEMS传感器，其中，所述基板和/或所述盖板围合所述真空腔体的部分设置有第一吸气层(20)；所述基板和/或所述盖板围合所述真空夹层腔体的部分设置有第二吸气层(21)。
  17. 根据权利要求16所述的MEMS传感器，其中，所述第一吸气层和/或所述第二吸气层的材料包括锆或钛。
  18. 根据权利要求13-17中任一项所述的MEMS传感器，其中，所述第一内焊接环和/或所述第一外焊接环朝向所述盖板方向依次包括：第一粘附层(11a)、第一阻挡层(11b)以及第一润湿层(11c)；所述第二内焊接环和/或所述第二外焊接环朝向所述基板方向依次包括：第二粘附层(12a)、第二阻挡层(12b)以及第二润湿层(12c)。
  19. 根据权利要求18所述的MEMS传感器，其中，所述第一粘附层和/或所述第二粘附层的材料包括钛或铬，所述第一阻挡层和/或所述第二阻挡层的材料包括镍，所述第一润湿层和/或所述第二润湿层的材料包括金。
  20. 根据权利要求13，14，16-19中任一项所述的MEMS传感器，其中，
    所述第一内焊接环与所述第一外焊接环之间设置有第一连接桥(22)，所述第一连接桥包括第一内连接端(22a)与第一外连接端(22b)，所述第一内连接端连接于所述第一内焊接环，所述第一外连接端连接于所述第一外焊接环，所述第一内连接端的厚度与所述第一内焊接环的厚度相等，所述第一外连接端的厚度与所述第一外焊接环的厚度相等；和/或
    所述第二内焊接环与所述第二外焊接环之间设置有第二连接桥(23)，所述第二连接桥包括第二内连接端(23a)与第二外连接端(23b)，所述第二内连接端连接于所述第二内焊接环，所述第二外连接端连接于所述第二外焊接环，所述第二内连接端的厚度与所述第二内焊接环的厚度相等，所述第二外连接端的厚度与所述第二外焊接环的厚度相等。
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6555901B1 (en) * 1996-10-04 2003-04-29 Denso Corporation Semiconductor device including eutectic bonding portion and method for manufacturing the same
CN2626974Y (zh) * 2003-05-16 2004-07-21 中国科学院上海微系统与信息技术研究所 一种可实现微机电系统器件气密密封装的结构
US20130187245A1 (en) * 2012-01-19 2013-07-25 Taiwan Semiconductor Manufacturing Company, Ltd. Micro electro mechanical system structures
CN110155934A (zh) * 2019-04-22 2019-08-23 武汉衍熙微器件有限公司 一种mems器件及其制作方法
CN112758883A (zh) * 2021-01-21 2021-05-07 杭州海康微影传感科技有限公司 Mems传感器及其制作方法
CN112758884A (zh) * 2021-01-21 2021-05-07 杭州海康微影传感科技有限公司 Mems传感器
CN215288001U (zh) * 2021-01-21 2021-12-24 杭州海康微影传感科技有限公司 Mems传感器
CN215288002U (zh) * 2021-01-21 2021-12-24 杭州海康微影传感科技有限公司 Mems传感器

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6555901B1 (en) * 1996-10-04 2003-04-29 Denso Corporation Semiconductor device including eutectic bonding portion and method for manufacturing the same
CN2626974Y (zh) * 2003-05-16 2004-07-21 中国科学院上海微系统与信息技术研究所 一种可实现微机电系统器件气密密封装的结构
US20130187245A1 (en) * 2012-01-19 2013-07-25 Taiwan Semiconductor Manufacturing Company, Ltd. Micro electro mechanical system structures
CN110155934A (zh) * 2019-04-22 2019-08-23 武汉衍熙微器件有限公司 一种mems器件及其制作方法
CN112758883A (zh) * 2021-01-21 2021-05-07 杭州海康微影传感科技有限公司 Mems传感器及其制作方法
CN112758884A (zh) * 2021-01-21 2021-05-07 杭州海康微影传感科技有限公司 Mems传感器
CN215288001U (zh) * 2021-01-21 2021-12-24 杭州海康微影传感科技有限公司 Mems传感器
CN215288002U (zh) * 2021-01-21 2021-12-24 杭州海康微影传感科技有限公司 Mems传感器

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