INTEGRATED MEMS SYSTEM

• US 20160320426A1
• Filed: 07/11/2016
• Published: 11/03/2016
• Est. Priority Date: 01/09/2014
• Status: Active Grant

• Current Assignee: Motion Engine inc
• Original Assignee: Motion Engine inc
• Inventors: Boysel, Robert Mark, Ross, Louis
• Granted Patent: US 10,214,414 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2201/0278 Temperature sensors
• CPC Class Codes: B81B 2201/0292 Sensors not provided for in B81B2201/0207 - B81B2201/0285
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: H01L 2224/16145 the bodies being stacked

Abstract

The present invention provides a 3D System (“3DS”) MEMS architecture that enables the integration of MEMS devices with IC chips to form a System on Chip (SoC) or System in Package (SiP). The integrated MEMS system comprises at least one MEMS chip, including MEMS transducers, and at least one IC chip, including not only MEMS processing circuitry, but also additional/auxiliary circuitry to process auxiliary signals. The MEMS chip can include first and second insulated conducting pathways. The first pathways conduct the MEMS-signals between the transducers and the IC chip, for processing; and the second conducting pathways can extend through the entire thickness of the MEMS chip, to conduct auxiliary signals, such as power, RF, I/Os, to the IC chip, to be processed the additional circuitry.

Claims

1. An integrated MEMS system comprising:

at least one MEMS chip comprising;

a first cap layer including a first set and a second set of first cap MEMS electrical contacts;

a second cap layer comprising second cap MEMS electrical contacts;

a central MEMS layer located between the first cap layer and the second cap layer;

at least one transducer formed in the first cap layer, the central MEMS layer and the second cap layer, the at least one transducer producing motion or sensing at least one parameter;

first insulated conducting pathways connecting said at least one transducer to the first set of first cap MEMS electrical contacts, the first insulated conducting pathways conducting electrical MEMS signals between said at least one transducer and the first set of the first cap MEMS electrical contacts; and

second insulated conducting pathways connecting the second set of first cap MEMS electrical contacts to at least one of the second cap MEMS electrical contacts, the second insulated conducting pathways extending through the first cap layer, the central MEMS layer, and the second cap layer, for conducting further signals through the MEMS chip; and

at least one signal IC chip comprising;

a first set and a second set of IC electrical contacts, the first set of IC electrical contacts being bonded to the first set of first cap MEMS electrical contacts and the second set of IC electrical contacts being bonded to the second set of first cap MEMS electrical contacts;

MEMS signal processing circuitry, operatively connected to the first set of IC electrical contacts, the MEMS signal processing circuitry configured to process the electrical MEMS signals; and

second signal processing circuitry, operatively connected to the second set of IC electrical contacts, the second signal processing circuitry configured to process the further signals.

2. The integrated MEMS system according to claim 1, wherein the first cap layer, the central MEMS layer and the second cap layer are made of an electrically conducting material, the first cap layer being electrically bonded to a first side of the central MEMS layer, and the second cap layer being electrically bonded to a second side of the central MEMS layer, opposite the first side.

3. The integrated MEMS system according to claim 1, wherein the first cap layer, the central MEMS layer and the second cap layer are fabricated from respective silicon wafers bonded at wafer level.

4. The integrated MEMS system according to claim 1, wherein the central MEMS layer comprises a silicon on insulator wafer and includes a moveable mass in a range of 0.5-1.5 milligrams, as is in a range of 1.5-3 milligrams or is in a range of 3-6 milligrams.

5. The integrated MEMS system according to claim 1, wherein the second insulated conducting pathways are formed by one or more trenches etched in at least one of the first layer, the central MEMS layer and the second layer, said one or more trenches being aligned and filled with an insulating material, the one or more trenches surrounding respective conductive wafer plugs, the conductive wafer plugs configured to transmit electrical signals though the entire thickness of the MEMS chip.

6. The integrated MEMS system according to of claim 1, wherein at least a plurality of the second insulated conducting pathways are formed by trenches etched in one of the first layer, the central MEMS layer and the second layer, said trenches being aligned and having their respective sidewalls lined with an insulating material and filled with a conductive material.

7. The integrated MEMS system according to claim 1, wherein the first MEMS electrical contacts and second cap MEMS electrical contacts of the first cap layer and the second cap layer are bond pads.

8. The integrated MEMS system according to claim 1, wherein said at least one transducer comprises a six degree of freedom motion sensor, and wherein said at least one parameter comprises three axes of linear acceleration and three axes of angular rate.

9. The integrated MEMS system according to claim 8, wherein said six degree of freedom motion sensor comprises a first set of electrodes and a second set of electrodes, the first set of electrodes positioned in the first cap layer and the second set of electrodes positioned in the second cap layer and a plurality of proof masses positioned in the central MEMS layer, the first and second sets of electrodes forming capacitors with the plurality of proof masses, a plurality of the first insulated conducting pathways configured to connect the first set of electrodes and the second set of electrodes to at least a plurality of the first cap MEMS electrical contacts of the first set of MEMS electrical contacts.

10. The integrated MEMS system according to claim 1, wherein said at least one transducer comprises at least one non-inertial sensor.

11. The integrated MEMS system according claim 10, wherein said at least one non-inertial sensor comprises at least one of a pressure sensor, a magnetometer, a thermometer, and a microphone.

12. The integrated MEMS system according to claim 10, wherein said at least one non-inertial sensor comprises non-inertial electrodes patterned in the first layer and at least one MEMS structure patterned in the central MEMS layer, a plurality of the first insulated conducting pathways connect said electrodes of the at least one non-inertial sensor to at least one of the first set of first cap MEMS electrical contacts.

13. The integrated MEMS system according to claim 1, wherein at least one of the electrical MEMS signals are analog signals, the IC chip comprising mixed signal CMOS circuitry to convert analog signals transmitted by the MEMS chip into digital signals, the digital signals being processed by the MEMS signal processing circuitry, and wherein the mixed signal CMOS circuitry is configured to convert digital signals transmitted by the MEMS signal processing circuitry into analog signals for connection to the MEMS chip.

14. The integrated MEMS system according to claim 1, wherein the IC chip comprises a digital bus, the MEMS signal processing circuitry comprising digital CMOS circuitry connected to said mixed signal circuitry via said digital bus.

15. The integrated MEMS system according to claim 14, wherein the digital CMOS circuitry comprises at least one of:

a digital data analysis circuitry, a digital input/output circuitry, a memory, a system controller and a calibration/compensation circuit.

16. The integrated MEMS system according to claim 14, wherein the IC chip comprises a power bus and wherein the further signal processing circuitry comprises power management circuitry connected to the power bus and to the digital bus.

17. The integrated MEMS system according to claim 14, wherein the IC chip comprises high speed CMOS circuitry connected to the digital bus, for processing the further signals.

18. The integrated MEMS system according to claim 17, wherein the high speed CMOS circuitry comprises at least one of an input-output module for wireless or GPS signals.

19. The integrated MEMS system according to claim 1, wherein said at least one single MEMS chip comprises a first single MEMS chip and at least one additional single MEMS chip, the first single MEMS chip and said at one additional single MEMS chip being stacked vertically, the second layer of the first single MEMS chip being bump bonded to the first layer of said at least one additional single MEMS chip, the second insulated conducting pathways of said at least additional single MEMS chip being electrically connected to at least one of the second insulated conducting pathways of the first single MEMS chip, for conducting auxiliary signals through the first MEMS chip and said at least one additional single MEMS chip, to the at least one IC chip.

20. The integrated MEMS system according to claim 19, wherein the first MEMS chip comprises a third set of first cap MEMS electrical contacts and third insulated conducting pathways connecting the first cap MEMS electrical contacts of the third set to at least some of the second cap MEMS electrical contacts, through the first cap layer, the central MEMS layer and the second cap layer, said third insulated conducting pathways being electrically connected to the MEMS signal processing circuitry of the at least one IC chip, and being electrically connected to insulated conducting pathways of said at least one additional single MEMS chip, the MEMS signal processing circuitry processing the electrical MEMS signals of the first MEMS chip and of said at least one additional single MEMS chips.

21. The integrated MEMS system according to claim 1, wherein said at least one single IC chip comprises a first single IC chip and at least one additional single IC chip.

22. The integrated MEMS system according to claim 1, further comprising a first proof mass having a thickness in a range of 100 microns to 1000 microns.

23. The integrated MEMS system according to claim 22, further comprising a second proof mass having a thickness in a range of 100 microns to 1000 microns.

24. The integrated MEMS system according to claim 23, further comprising a controller configured to operate the first proof mass and the second proof mass in an antiphase drive mode.

25. An integrated MEMS system comprising:

at least one MEMS chip comprising;

a first cap layer including a first set and a second set of first cap MEMS electrical contacts;

a second cap layer comprising second cap MEMS electrical contacts;

a central MEMS layer located between the first cap layer and the second cap layer;

at least one transducer formed in the first cap layer, the central MEMS layer and the second cap layer, the at least one transducer having a moveable mass in a range of 0.1-15 milligrams.

26. The integrated MEMS system of claim 25 further comprising:

first insulated conducting pathways connecting said at least one transducer to the first set of first cap MEMS electrical contacts, the first insulated conducting pathways conducting electrical MEMS signals between said at least one transducer and the first set of the first cap MEMS electrical contacts; and

second insulated conducting pathways connecting the second set of first cap MEMS electrical contacts to at least one of the second cap MEMS electrical contacts, the second insulated conducting pathways extending through the first cap layer, the central MEMS layer, and the second cap layer, for conducting further signals through the MEMS chip.

27. The integrated MEMS system of claim 25 wherein the system has a noise density and bias stability.

28. A method of operating a MEMS transducer device comprising:

operating a MEMS transducer device including a first cap layer having first cap electrical contacts, a second cap layer having second cap electrical contacts, and a central MEMS layer including a first moveable mass in a range of 0.1 to 15 milligrams and a second moveable mass in a range of 0.1 to 15 milligrams; and

transmitting electrical signals between the MEMS transducer device and an integrated circuit (IC) chip such that the device operates in an antiphase drive mode.

29. The method of claim 29 wherein at least the first moveable mass is in a range of 0.5-1.5 milligrams, or is in a range of 1.5-3 milligrams, or is in a range of 3-6 milligrams.