Silicon device

• US 6,759,591 B2
• Filed: 02/06/2003
• Issued: 07/06/2004
• Est. Priority Date: 06/13/2001
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Ngo, Hung V.
• Application Number:
  US10/343,963
• Publication Number:
  US 20030180504A1
• Time in Patent Office: 516 Days
• Field of Search: 174/52.4, 735/141.6, 735/143.2, 735/142.9
• US Class Current: 174/520
• 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 includes an insulating substrate having a recess on the surface of the substrate, and a beam-like structure made of silicon on the front surface of the insulating substrate, surrounds the recess. The beam-like structure includes at least one functional section having a supporting section bonded to the insulating substrate and at least one cantilever integral with the supporting section and extending across the recess. The silicon device also includes a frame made of silicon surrounding and spaced from the beam-like structure and on the insulating substrate. The silicon device also includes a conductive film having electrical continuity with the frame and on the surface of the insulating substrate, at least in a portion directly opposite the cantilever. The conductive film prevents the insulating substrate from being charged, thereby significantly suppressing damage of the beam-like structure during dry etching.

Claims

1. A silicon device comprising:

an insulating substrate having a surface including a recess,

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

a frame made of silicon surrounding and spaced from the beam-like structure and on the insulating substrate; and

a conductive film having electrical continuity with the frame and on the surface of the insulating substrate, at least directly opposite the cantilever.

2. The silicon device according to claim 1, wherein the beam-like structure comprises at least two functional sections that are electrically insulated from each other and have substantially identical volumes.

3. The silicon device according to claim 2, wherein the silicon device is an acceleration sensor and the 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 identical volumes.

5. The silicon device according to claim 2, wherein the silicon device is an angular velocity sensor and the functional sections are a movable electrode and a fixed electrode, each of the movable and fixed electrodes having a comb-shaped electrode including a plurality of cantilevers extending across the recess, the movable electrode being supported on the frame for vibrating generally parallel to the surface of the insulating substrate, and the fixed electrode being bonded to the insulating substrate, the cantilevers of the movable electrode and the fixed electrode opposing each other across a gap.

6. A silicon device comprising:

an insulating substrate having a surface including a recess,

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

a frame made of silicon, surrounding and spaced from the beam-like structure and on the insulating substrate; and

a conductive film having electrical continuity with the supporting section of the functional structure having the larger volume, and on the surface of the insulating substrate, at least directly opposite the cantilever.

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