Micro inertia sensor and method of manufacturing the same

• US 6,789,423 B2
• Filed: 12/27/2002
• Issued: 09/14/2004
• Est. Priority Date: 03/27/2002
• Status: Expired due to Fees

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kim, Kyoung Soo, An, Seung Do, Cho, Ji Man
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US10/330,710
• Publication Number:
  US 20030183009A1
• Time in Patent Office: 627 Days
• Field of Search: 735/041.4, 735/041.2, 735/040.2, 735/040.4, 735/143.2, 735/141.6, 735/142.9
• US Class Current: 73/504.04
• CPC Class Codes: B81B 2201/025 Inertial sensors not provided for in B81B2201/0235 - B81B2201/0242
• CPC Class Codes: B81B 2207/095 through the lid
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 2201/019 Bonding or gluing multiple substrate layers
• CPC Class Codes: B81C 2203/0118 Bonding a wafer on the substrate, i.e. where the cap consists of another wafer
• CPC Class Codes: B81C 2203/038 Bonding techniques not provided for in B81C2203/031 - B81C2203/037
• CPC Class Codes: G01C 19/5783 Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0814 for translational movement of the mass, e.g. shuttle type
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends
• CPC Class Codes: Y10T 428/24322 Composite web or sheet

Abstract

The present invention provides a micro inertia sensor and a method of manufacturing the same, the micro inertia sensor includes a lower glass substrate; a lower silicon including a first border, a first fixed point and a side movement sensing structure; an upper silicon including a second border, a second fixed point being connected to a via hole, in which a metal wiring is formed, on an upper side, and an sensing electrode, which correspond to the first border, the first fixed point and the side movement sensing structure; a bonded layer by a eutectic bonding between the upper silicon and the lower silicon; and a upper glass substrate, being positioned on an upper portion of the upper silicon, for providing the via hole on which an electric conduction wiring is formed, thereby aiming at the miniaturization of the product and the simplification of the process.

Claims

1. A micro inertia sensor comprising

a lower glass substrate;

a lower silicon including a first border, a first fixed point and a side movement sensing structure;

an upper silicon including a second border, a second fixed point being connected to a via hole, in which a metal wiring is formed, on an upper side, and a sensing electrode, which correspond to the first border, the first fixed point and the side movement sensing structure;

a bonded layer by an eutectic bonding between the upper silicon and the lower silicon; and

an upper glass substrate, being positioned on an upper portion of the upper silicon, for providing the via hole on which an electric conduction wiring is formed.

2. The micro inertia sensor according to claim 1, wherein the side movement sensing structure comprises a structure being movable in a horizontal direction and a sensing electrode for sensing a variation of a capacity as the structure horizontally moves.

3. The micro inertia sensor according to claim 1, wherein the sensing electrode senses the capacity in a vertical direction.

4. The micro inertia sensor according to claim 1, wherein the bonded layer by the eutectic bonding is formed by Au—

Si eutectic bonding.

5. The micro inertia sensor according to claim 1, wherein the via hole is formed on the upper glass substrate, extending to the inside of the second fixed point of the upper silicon.

6. A micro inertia sensor comprising:

a lower substrate;

a device wafer comprising a lower silicon including a structure on which a first border, a first fixed point and a first sensing electrode for sensing a capacity in a horizontal direction are formed on the same surface of the lower substrate;

an upper silicon including a second border, a second fixed point and a second sensing electrode for sensing a capacity in a vertical direction between the structure, which correspond to the first border, the first fixed point and the structure on the lower silicon, respectively;

a cap wafer, being positioned on an upper portion of the upper silicon, and including an upper substrate providing a via hole connected to a metal wiring; and

a bonded layer by an eutectic bonding between the upper silicon and the lower silicon.

7. The micro inertia sensor according to claim 6, wherein the via hole is formed on the upper substrate, extending to the inside of the second fixed point of the upper silicon.

8. The micro inertia sensor according to claim 6, wherein the lower substrate and the upper substrate are made of glass.

9. The micro inertia sensor according to claim 6, wherein the via hole is formed in a “

V”

shape from the upper substrate to the inside of the upper silicon, by evaporating a metal film of an electric conductivity.

10. The micro inertia sensor according to claim 6, wherein the device wafer and the cap wafer are SOG (silicon on glass) wafer.

11. The micro inertia sensor according to claim 6, wherein the device wafer and the cap wafer are SOI (silicon on insulator) wafer.

12. The micro inertia sensor according to claim 6, wherein the device wafer and the cap wafer are LPCVD polysilicon wafer.

13. The micro inertia sensor according to claim 6, wherein the device wafer and the cap wafer are Epi polysilicon wafer.