Semiconductor dynamic quantity sensor

• US 7,004,029 B2
• Filed: 06/01/2004
• Issued: 02/28/2006
• Est. Priority Date: 06/02/2003
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sakai, Minekazu
• Primary Examiner(s): Kwok, Helen C.
• Application Number:
  US10/856,858
• Publication Number:
  US 20040237652A1
• Time in Patent Office: 637 Days
• Field of Search: 735/143.2, 735/142.9, 735/040.4, 735/041.2, 735/041.3, 735/041.4, 735/041.5
• US Class Current: 73/514.32
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

In a semiconductor acceleration sensor (S1), above one side of a first silicon substrate (10) made of a semiconductor and serving as a fixed electrode (11), a moving electrode (20) made of a semiconductor and displaceable in the thickness direction of the first silicon substrate (10) is disposed apart from and facing the first silicon substrate (10). An applied acceleration is detected on the basis of capacitance changes between the moving electrode (20) and the face of the first silicon substrate (10) accompanying displacement of the moving electrode (20). A space and an electrically insulative insulating layer (13) having a relative permittivity larger than that of air are interposed between the moving electrode (20) and the face of the first silicon substrate (10), side by side in the direction in which the moving electrode (20) and the first silicon substrate (10) are apart.

Claims

1. A semiconductor dynamic quantity sensor having a moving electrode and a fixed electrode apart from and facing each other formed by processing a semiconductor substrate, the semiconductor dynamic quantity sensor detecting an applied dynamic quantity on the basis of a capacitance change between the moving electrode and the fixed electrode accompanying displacement of the moving electrode occurring when the dynamic quantity is applied, wherein a space and an electrically insulative insulating layer having a larger relative permittivity than air are interposed between the moving electrode and the fixed electrode side by side in the direction in which the electrodes are apart, wherein the insulating layer insulates the moving electrode from the fixed electrode, and the insulating layer is formed by etching a portion of the moving electrode.

2. A semiconductor dynamic quantity sensor according to claim 1, wherein the insulating layer is provided on at least one of the mutually facing sides of the moving electrode and the fixed electrode.

3. A semiconductor dynamic quantity sensor according to claim 2, wherein the insulating layer is provided on both of the mutually facing sides of the moving electrode and the fixed electrode.

4. A semiconductor dynamic quantity sensor according to claim 1, wherein the insulating layer is made up of a plurality of insulating films of different types.

12. A semiconductor dynamic quantity sensor according to claim 1, further comprising an electrode for outputting an electrical potential of the fixed electrode from a surface where the moving electrode is formed.

5. A semiconductor dynamic quantity sensor having a supporting substrate constituting a fixed electrode made of a semiconductor and disposed apart from and facing one side of a moving electrode made of a semiconductor and displaceable in the thickness direction of the supporting substrate, the semiconductor dynamic quantity sensor detecting an applied dynamic quantity on the basis of a capacitance change between the moving electrode and one side of the supporting substrate accompanying displacement of the moving electrode occurring when the dynamic quantity is applied, wherein a space and an electrically insulative insulating layer having a larger relative permittivity than air are interposed between the moving electrode and one side of the supporting substrate side by side in the direction in which the moving electrode and the supporting substrate are apart, wherein the insulating layer insulates the moving electrode from the fixed electrode, and the insulating layer is formed by etching a portion of the moving electrode.

6. A semiconductor dynamic quantity sensor according to claim 5, wherein the insulating layer is provided on at least one of the mutually facing sides of the moving electrode and the supporting substrate.

7. A semiconductor dynamic quantity sensor according to claim 6, wherein the insulating layer is provided on both of the mutually facing sides of the moving electrode and the supporting substrate.

8. A semiconductor dynamic quantity sensor according to claim 5, wherein the insulating layer is made up of a plurality of insulating films of different types.

11. A semiconductor dynamic quantity sensor according to claim 5, further comprising an electrode for outputting an electrical potential of the fixed electrode from a surface where the moving electrode is formed.

9. A semiconductor dynamic quantity sensor having a moving electrode and a fixed electrode apart from and facing each other formed by processing a semiconductor substrate, the semiconductor dynamic quantity sensor detecting an applied dynamic quantity on the basis of a capacitance change between the moving electrode and the fixed electrode accompanying displacement of the moving electrode occurring when the dynamic quantity is applied, wherein a space and an electrically insulative insulating layer having a larger relative permittivity than air are interposed between the moving electrode and the fixed electrode side by side in the direction in which the electrodes are apart, wherein the insulating layer is provided on at least one of the mutually facing sides of the moving electrode and the fixed electrode, wherein the insulating layer is made up of a plurality of insulating films of different types, wherein the insulating layer insulates the moving electrode from the fixed electrode, and the insulating layer is formed by etching a portion of the moving electrode.

10. A semiconductor dynamic quantity sensor according to claim 9, further comprising an electrode for outputting an electrical potential of the fixed electrode from a surface where the moving electrode is formed.