Silicon MEMS gyroscopes with upper and lower sense plates

Patent metadata

Field	Value
Publication number	US-12092460-B2
Application number	US-202217980045-A
Country	US
Kind code	B2
Filing date	Nov 3, 2022
Priority date	Sep 24, 2018
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

Methods for fabricating MEMS tuning fork gyroscope sensor system using silicon wafers. This provides the possibly to avoid glass. The sense plates can be formed in a device layer of a silicon on insulator (SOI) wafer or in a deposited polysilicon layer in a few examples.

First claim

What is claimed is:

1. A tuning fork gyroscope sensor, comprising:
a silicon sense plate wafer including a silicon handle layer including vias for electrical connections, wherein the silicon sense plate wafer is a silicon on insulator (SOI) wafer;
a silicon proof mass wafer, including a proof mass, bonded to the silicon sense plate wafer; and
a sealing ring around the proof mass.

2. The sensor as claimed in claim 1 , wherein the silicon sense plate wafer further includes a silicon oxide layer.

3. The sensor as claimed in claim 1 , further comprising vias through the silicon handle layer for wire bonding into the vias to establish electrical connections for the sensor.

4. The sensor as claimed in claim 1 , further comprising vias through the handle layer which are filled with conductive material to provide electrical connections for the sensor.

5. The sensor as claimed in claim 1 , further comprising another silicon sense plate wafer on the other side of the proof mass wafer.

6. The sensor as claimed in claim 1 , wherein the silicon sense plate wafer is direct bonded to the silicon wafer proof mass wafer.

7. The sensor as claimed in claim 1 , wherein the silicon sense plate is metal bonded to the silicon wafer proof mass.

8. A tuning fork gyroscope sensor, comprising:
a silicon sense plate wafer including a silicon handle layer including vias for electrical connections;
a silicon proof mass wafer bonded to the silicon sense plate wafer; and
a sealing ring around the proof mass, wherein a volumetric region in the sealing ring and around the proof mass is evacuated.

9. The sensor as claimed in claim 8 , wherein the sealing ring is a perimeter mesa.

10. A tuning fork gyroscope sensor, comprising:
a silicon sense plate wafer including a silicon handle layer including vias for electrical connections; and
a silicon proof mass wafer bonded to the silicon sense plate wafer;

wherein the sense plate is a conductive polysilicon layer deposited on an insulating layer.

11. The sensor as claimed in claim 10 , further comprising a sealing ring around the proof mass.

12. The sensor as claimed in claim 11 , wherein the sealing ring is a perimeter mesa.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Cook Eugene H
• Bernstein Jonathan J
• Bancu Mirela G
• Weinberg Marc Steven
• Sawyer William

Classifications

• B81C2203/035

  Soldering · CPC title

• B81B2207/096

  through the substrate · CPC title

• B81B2201/0242

  Gyroscopes · CPC title

• B81C2201/0133

  Wet etching · CPC title

• B81C2201/0132

  Dry etching, i.e. plasma etching, barrel etching, reactive ion etching [RIE], sputter etching or ion milling · CPC title