Silicon device

• US 20030180504A1
• Filed: 02/06/2003
• Published: 09/25/2003
• Est. Priority Date: 06/13/2001
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Yoshida, Yukihisa, Tsutsumi, Kazuhiko, Kumagai, Munehito
• Granted Patent: US 6,759,591 B2
• Time in Patent Office: Days
• US Class Current: 428/172
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass
• 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: Y10T 428/24612 Composite web or sheet

Abstract

A silicon device including an insulating substrate having a recess formed on the surface thereof, and a beam-like structure made of silicon formed on the front surface of the insulating substrate to surround the recess. The beam-like structure includes at least one functional section having a supporting section bonded onto the insulating substrate and at least one cantilever formed integrally with the supporting section while extending across the recess. The silicon device also includes a frame made of silicon that surrounds the beam-like structure with a space kept therefrom and is formed onto the insulating substrate. The silicon device also includes a conductive film having electrical continuity with the frame and formed on the surface of the insulating substrate at least in a portion right below the cantilever. The conductive film prevents the insulating substrate from being charged thereby significantly suppressing the damage caused on the beam-like structure during dry etching.

Claims

1. A silicon device comprising:

an insulating substrate having a recess formed on the surface thereof,

a beam-like structure made of silicon formed on the front surface of the insulating substrate to surround the recess, said beam-like structure comprising at least one functional section having a supporting section bonded onto the insulating substrate and at least one cantilever formed integrally with the supporting section while extending across the recess;

a frame made of silicon that surrounds the beam-like structure with a space kept therefrom and is formed onto the insulating substrate; and

a conductive film having electrical continuity with the frame and formed on the surface of the insulating substrate at least in a portion right below the cantilever.

2. The silicon device according to claim 1, wherein the beam-like structure comprise two or more functional sections that are electrically insulated from each other and have substantially the same volumes.

3. The silicon device according to claim 1, wherein the silicon device is an acceleration sensor and said functional sections are a movable electrode and a fixed electrode.

4. The silicon according to claim 3, wherein the movable electrode and the fixed electrode have substantially the same volumes.

5. The silicon device according to claim 1, wherein the silicon device is an angular velocity sensor and said functional sections are a movable electrode and a fixed electrode with each electrode having a comb-shaped electrode including a plurality of cantilevers extending across the recess, said movable electrode being supported on the frame so as to be capable of vibrating in the horizontal direction on the surface of the insulating substrate and said fixed electrode being bonded onto the insulating substrate, said cantilevers of the movable electrode and the fixed electrode being disposed to oppose each other via a minute clearance.

6. A silicon device comprising:

an insulating substrate having a recess formed on the surface thereof,

a beam-like structure made of silicon formed on the front surface of the insulating substrate to surround the recess, said beam-like structure comprising at least one functional section having a supporting section bonded onto the insulating substrate and at least one cantilever formed integrally with the supporting section while extending across the recess, said beam-like silicon structure comprising two or more functional structures that are electrically insulated from each other and have different volumes;

a frame made of silicon that surrounds the beam-like structure with a space kept therefrom and is formed onto the insulating substrate; and

a conductive film having electrical continuity with the supporting section of the functional section of the largest volume and formed on the surface of the insulating substrate at least in a portion right below the cantilever.

7. The silicon device according to claim 6, wherein the silicon device is an acceleration sensor and the functional sections are a movable electrode and a fixed electrode.