CAPACITIVE SENSING STRUCTURE WITH EMBEDDED ACOUSTIC CHANNELS

• US 20160068386A1
• Filed: 11/16/2015
• Published: 03/10/2016
• Est. Priority Date: 06/05/2013
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Chan, Mei-Lin, Li, Xiang, Lim, Martin
• Granted Patent: US 9,809,451 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81B 3/0021 Transducers for transforming electrical into mechanical energy or vice versa dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00
• CPC Class Codes: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: B81B 7/0006 Interconnects
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: B81C 2203/035 Soldering
• CPC Class Codes: B81C 2203/0785 Transfer and j oin technology, i.e. forming the electronic processing unit and the micromechanical structure on separate substrates and joining the substrates
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 7/08 comprising superposed layers separated by air or other fluid
• CPC Class Codes: H10N 30/204 using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
• CPC Class Codes: H10N 30/2047 Membrane type
• CPC Class Codes: H10N 30/302 Sensors
• CPC Class Codes: H10N 30/308 Membrane type

Abstract

A MEMS device includes a dual membrane, an electrode, and an interconnecting structure. The dual membrane has a top membrane and a bottom membrane. The bottom membrane is positioned between the top membrane and the electrode and the interconnecting structure defines a spacing between the top membrane and the bottom membrane.

Claims

1. A method of manufacturing a MEMS device comprising:

forming an electrode on top of a CMOS wafer;

forming a moveable dual-plate membrane with top and bottom membranes on top of a MEMS device wafer;

forming an interconnecting structure on the MEMS device wafer, between the top and bottom membranes, and bonding the CMOS wafer to the MEMS device wafer and causing electrical connection between the CMOS wafer and the MEMS device wafer.

2. The method of claim 1, wherein the bonding comprises eutectic bonding.

3. The method of claim 1, further including forming standoffs on the MEMS wafer.

4. The method of claim 1, further including depositing polysilicon on the MEMS wafer before forming the standoffs.

5. The method of claim 1, further including depositing a conductive structure layer on top of the standoffs and etching.

6. The method of claim 1, further including thinning the CMOS wafer.

7. The method of claim 1, wherein the forming a moveable dual membrane comprising forming a top membrane and a bottom membrane.

8. The method of claim 7, further including forming perforations in the bottom membrane.

9. The method of claim 1, further including forming an acoustic port in the CMOS wafer.