STRAIN SENSING ELEMENT, PRESSURE SENSOR, AND MICROPHONE

• US 20160258824A1
• Filed: 10/28/2015
• Published: 09/08/2016
• Est. Priority Date: 03/02/2015
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: OKAMOTO, Kazuaki, FUJI, Yoshihiko, HORI, Akio, MASUNISHI, Kei, FUKUZAWA, Hideaki, YUZAWA, Akiko
• Application Number:
  US14/925,494
• Publication Number:
  US 20160258824A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 7/24 using change in magnetic properties
• CPC Class Codes: G01L 1/12 by measuring variations in the magnetic properties of materials resulting from the application of stress
• CPC Class Codes: G01L 1/125 by using magnetostrictive means magnetostrictive sensors H10N35/101
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G01L 9/0051 using variations in ohmic resistance
• CPC Class Codes: G01L 9/007 using variations in inductance
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 Mems transducers or their use

Abstract

According to one embodiment, a strain sensing element provided at a deformable film part, includes a stacked body, a first electrode, and a second electrode. The stacked body includes a first magnetic layer, a second magnetic layer, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. A magnetization direction of the first magnetic layer changes in accordance with a deformation of the film part. The first electrode includes a first alloy layer including a first alloy including Ta and Mo. The first electrode is electrically connected to the stacked body. The second electrode is electrically connected to the stacked body.

Claims

1. A strain sensing element to be provided at a deformable film part, the element comprising:

a stacked body including a first magnetic layer, a second magnetic layer, and an intermediate layer provided between the first magnetic layer and the second magnetic layer, a magnetization direction of the first magnetic layer configured to change in accordance with a deformation of the film part;

a first electrode including a first alloy layer including a first alloy including Ta and Mo, the first electrode being electrically connected to the stacked body; and

a second electrode electrically connected to the stacked body.

2. The element according to claim 1, wherein the first alloy includes Ta_100-xMo_x (13 at. %≦

x≦

70 at. %).

3. The element according to claim 1, wherein the first alloy has a body-centered cubic structure.

4. The element according to claim 1, wherein an absolute value of residual stress of the first electrode is 100 megapascals or less.

5. The element according to claim 1, wherein

the stacked body is provided between the second electrode and the film part, and

the first electrode is provided between the stacked body and the film part.

6. The element according to claim 1, wherein the first electrode further includes a first intermediate metal layer including at least one of Cu and a first copper alloy, and the first copper alloy includes Cu and Ag.

7. The element according to claim 6, wherein the first alloy layer is provided between the first intermediate metal layer and the stacked body.

8. The element according to claim 6, wherein

the first electrode further includes a first metal layer provided between the first intermediate metal layer and the film part, and

the first metal layer includes a first Ta alloy including Ta and Mo.

9. The element according to claim 1, wherein the second electrode includes a second alloy layer including a second alloy including Ta and Mo.

10. The element according to claim 9, wherein

the second electrode further includes a second intermediate metal layer provided between the second alloy layer and the stacked body,

the second intermediate metal layer includes at least one of Cu and a second copper alloy, and the second copper alloy includes Cu and Ag.

11. The element according to claim 10, wherein

the second electrode further includes a second metal layer provided between the stacked body and the second intermediate metal layer, and

the second metal layer includes a second Ta alloy including Ta and Mo.

12. The element according to claim 1, wherein at least part of the first magnetic layer is amorphous.

13. The element according to claim 1, wherein the first magnetic layer includes boron.

14. The element according to claim 1, wherein boron concentration in at least part of the first magnetic layer is 5 at. % or more and 35 at. % or less.

15. The element according to claim 1, wherein the intermediate layer includes at least one of oxide, nitride, and oxynitride.

16. The element according to claim 1, wherein the intermediate layer includes magnesium oxide.

17. The element according to claim 1, wherein

the stacked body further includes an underlayer provided between the second magnetic layer and the first electrode, and

at least part of the underlayer is amorphous.

18. The element according to claim 1, wherein

the stacked body further includes an underlayer provided between the second magnetic layer and the first electrode, and

the underlayer includes a first layer including Cu and a second layer including Ta, the second layer being provided on the first layer.

19. A pressure sensor comprising:

the film part;

a support part supporting the film part; and

one or a plurality of the strain sensing elements according to claim 1 provided on the film part.

20. A microphone comprising:

the pressure sensor according to claim 19.