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US 12,631,491 B2Granted
Wafer level vacuum packaging (WLVP) of thermal imaging sensor
AssigneeMeridian Innovation Pte Ltd
InventorsIlker Ender Ocak, Piotr Kropelnicki
Life of this patent
Estimating the term…
Abstract
A complementary metal oxide semiconductor (CMOS) device embedded with microelectromechanical system (MEMS) components in a MEMS region. The MEMS components, for example, are infrared (IR) thermosensors. The device is encapsulated with a CMOS compatible IR transparent cap to hermetically seal the device using wafer-level vacuum packaging techniques.
Claims18
A device comprising:
- a substrate, wherein the substrate is configured with
- a complementary metal oxide semiconductor (CMOS) region with CMOS components, and
- a microelectromechanical system (MEMS) region with an array of MEMS sensors, wherein the MEMS region includes
- an array of substrate cavities below a top surface of the substrate, and
- wherein the array of MEMS sensors is suspended over the array of substrate cavities, with a substrate cavity of the array of substrate cavities disposed under a MEMS sensor of the array of MEMS sensors;
- a backend (BE) dielectric with interconnects for interconnecting the CMOS components disposed on the substrate over the CMOS and MEMS regions, wherein the BE dielectric is patterned to expose the array of MEMS sensors in the MEMS region with the array of substrate cavities below the array of MEMS sensors;
- a substrate sealing ring on a substrate bonding region on the BE dielectric, the substrate bonding region surrounds the MEMS region and the CMOS region;
- a cap, wherein the cap comprises a cap bonding region surrounding at a periphery of the cap, the cap bonding region includes a cap sealing ring;
- wherein the cap sealing ring and the substrate sealing ring forms a cap bond to bond the cap onto the substrate, the cap encapsulates the MEMS region and the CMOS region, wherein the cap creates a cap cavity over the MEMS region, the cap cavity is a vacuum cavity;
- and
- cap support posts, wherein the cap support posts are disposed in the CMOS region within the cap cavity between a surface of the BE dielectric and the cap, and the cap support posts are configured to provide mechanical support to prevent the cap from contacting the MEMS region during bonding.
8 more elements
A device comprising:
- a substrate, wherein the substrate is configured with
- a complementary metal oxide semiconductor (CMOS) region with CMOS components, and
- a microelectromechanical system (MEMS) region with a MEMS component, the MEMS component includes thermoelectric infrared (IR) sensors to form a sensor array, wherein a sensor of the sensor array comprises
- a substrate cavity, the substrate cavity includes cavity sidewalls and a cavity bottom defined by the substrate,
- an infrared MEMS sensor disposed over a dielectric layer which defines the top of the substrate cavity,
- substrate cavity walls separating adjacent substrate cavities to form an array of substrate cavities for the sensor array, and
- a reflector disposed at the bottom of the substrate cavity, the reflector is configured to reflect IR radiation;
- a backend (BE) dielectric with interconnects for interconnecting the CMOS components disposed on the substrate over the CMOS and the MEMS regions, the BE dielectric includes an interlayer dielectric (ILD) level, a back-end-of-line (BEOL) dielectric and passivation layers, the BE dielectric is removed to create an opening exposing the sensor array, wherein the opening forms a backend (BE) cavity, wherein the BE dielectric over the MEMS region is patterned to be disposed over the substrate cavity walls forming individual BE cavities over the substrate cavities;
- a substrate sealing ring on a substrate bonding region on the BE dielectric, the substrate bonding region surrounds the MEMS region and the CMOS region;
- a cap, wherein the cap comprises a cap bonding region surrounding a periphery of the cap, the cap bonding region includes a cap sealing ring;
- wherein the cap sealing ring and the substrate sealing ring form a sealing ring having a height and being arranged to bond the cap onto the substrate, defining the height of the sealing ring, the cap encapsulates the MEMS region and the CMOS region, wherein the cap creates a cap cavity over the MEMS region, the cap cavity is a vacuum cavity;
- and
- an anti-reflective region comprising a surface pattern disposed on the cap over the MEMS region, the anti-reflective region is disposed on a top cap surface or a bottom cap surface of the cap, the anti-reflective region is configured to increase transmission of IR light having a target wavelength.
10 more elements
Dependencies are inferred from the claim text.