MEMS sensor, MEMS sensor manufacturing method, and electronic device

• US 8,338,896 B2
• Filed: 03/25/2010
• Issued: 12/25/2012
• Est. Priority Date: 03/26/2009
• Status: Active Grant

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kanemoto, Kei
• Primary Examiner(s): Mandala, Victor A
• Assistant Examiner(s): Schoenholtz, Joseph
• Application Number:
  US12/731,572
• Publication Number:
  US 20100244160A1
• Time in Patent Office: 1,006 Days
• Field of Search: None
• US Class Current: 257/415
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/123 by piezo-resistive elements, e.g. semiconductor strain gauges
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: H01L 29/84 controllable by variation of applied mechanical force, e.g. of pressure

Abstract

A MEMS sensor formed by processing a multi-layer wiring structure, includes: a movable weight portion coupled to a fixed frame portion with an elastic deformable portion and having a hollow portion formed at the periphery; a capacitance electrode portion including a fixed electrode portion fixed to the fixed frame portion and a movable electrode portion connected to the movable weight portion and arranged to face the fixed electrode portion; and an adjusting layer for adjusting at least one of amass of the movable weight portion, a damping coefficient of the movable electrode portion, and spring characteristics in the elastic deformable portion, wherein the adjusting layer includes at least one insulating layer that is a constituent element of the multi-layer wiring structure.

Claims

1. A MEMS sensor comprising:

a support portion;

a movable weight portion;

an elastically deformable connection portion connecting the support portion and the movable weight portion;

a fixed electrode portion extending from the support portion;

a movable electrode portion extending from the movable weight portion and disposed opposed to the fixed electrode portion; and

first through third adjusting layers, wherein

the first adjusting layer is provided at the movable weight portion, the second adjusting layer is provided at the fixed and movable electrode portions, and the third adjusting layer is provided at the elastically deformable connection portion.

2. The MEMS sensor according to claim 1, wherein

the first through third adjusting layers include an insulated layer.

3. The MEMS sensor according to claim 1, wherein

the first through third adjusting layers are formed on top or bottom of the movable weight portion, the fixed and movable electrode portions, and the elastically deformable connection portion, respectively.

4. The MEMS sensor according to claim 1, wherein

the movable weight portion is a laminated layer structure including:

a plurality of conductive layers, and

inter-layer insulating layers which are disposed between the adjoining conductive layers of the plurality of conductive layers.

5. The MEMS sensor according to claim 4, wherein

each of the inter-layer insulating layers is an embedded plug having a specific gravity larger than that of the inter-layer insulating layers.

6. The MEMS sensor according to claim 1, wherein

a thickness of the first adjusting layer is different from the thickness of at least one of the second adjusting layer and the third adjusting layer.

7. The MEMS sensor according to claim 1, wherein

a layer-structure of the first adjusting layer is different from a layer-structure of at least one of the second adjusting layer and the third adjusting layer.

8. An electronic device comprising the MEMS sensor according to claim 1.

9. A MEMS sensor manufacturing method for a MEMS sensor including a support portion;

a movable weight portion;

an elastically deformable connection portion connecting the support portion and the movable weight portion;

a fixed electrode portion extending from the support portion; and

a movable electrode portion extending from the movable weight portion and disposed opposed to the fixed electrode portion, comprising;

forming a laminated layer structure on a substrate;

forming an adjusting layer at a top or bottom of the laminated layer structure;

forming a first cavity portion from the top of the laminated layer structure to a surface of the substrate, by anisotropic etching; and

isotropically etching the substrate via the first cavity portion to form a second cavity portion between the substrate and the laminated layer structure.