Gas detection device

Patent metadata

Field	Value
Publication number	US-10794886-B2
Application number	US-201916366162-A
Country	US
Kind code	B2
Filing date	Mar 27, 2019
Priority date	May 30, 2016
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A gas detection device includes a substrate having a main surface and a movable film structure located on, and including a portion thereof spaced from, the main surface of the substrate. The portion of the movable film structure located over and spaced from the substrate includes a first film formed of an insulating material, a patterned second film which deforms as a result of absorbing or adsorbing a predetermined gas, and a patterned third film comprising a resistive heater, at least a portion of the movable film structure spaced from the substrate being movable with respect to the substrate. From the perspective of a direction perpendicular to the main surface of the substrate, at least a portion of a pattern of the second film overlaps at least a portion of a pattern of the third film.

First claim

What is claimed is:

1. A gas detection device, comprising:
a substrate; and
a movable film structure, a portion of which extends over and is spaced from the substrate so that a cavity is provided between the portion of the movable film structure and the substrate, the movable film structure having a plurality of through holes leading to the cavity, the movable film structure including a first film of an insulating material and a second film which deforms as a result of absorbing or adsorbing a predetermined gas.

2. The gas detection device according to claim 1 , wherein the movable film structure further includes a moisture preventive film that covers the second film.

3. The gas detection device according to claim 1 , further comprising:
a heating unit that heats the second film.

4. The gas detection device according to claim 1 , wherein the insulating material comprises a brittle material.

5. The gas detection device according to claim 1 , wherein the first film comprises silicon (Si).

6. The gas detection device according to claim 1 , wherein the first film comprises at least one of silicon nitride, silicon oxide, and silicon carbide.

7. The gas detection device according to claim 1 , wherein the predetermined gas is hydrogen, a hydrogen-containing gas, water vapor, or a volatile organic compound gas.

8. The gas detection device according to claim 1 , wherein the movable film structure further comprises a resistive film.

9. The gas detection device according to claim 1 , wherein
a portion of the movable film structure extends from a position at which the movable film structure is fixed to the substrate, and
the portion of the movable film structure is spaced from the substrate and movable with respect to the substrate in parallel to the main surface of the substrate.

10. The gas detection device according to claim 9 , wherein a portion of the second film extends from the position at which the movable film structure is fixed to the substrate.

11. The gas detection device according to claim 1 , wherein the predetermined gas is hydrogen or a hydrogen-containing gas.

12. The gas detection device according to claim 11 , wherein the second film comprises one of palladium (Pd), an alloy containing palladium (Pd), an alloy containing titanium (Ti), or an alloy containing lanthanum (La).

13. The gas detection device according to claim 1 , further comprising:
a first conductive portion located on the substrate, the first conductive portion forming a first electrode of a variable capacitor, wherein
the movable film structure includes a portion thereof forming a second electrode of the variable capacitor.

14. The gas detection device according to claim 13 , wherein
a portion of the movable film structure extends from a position at which the movable film structure is fixed to the substrate, and the portion of the movable film structure located over and spaced from the substrate extends in a predetermined direction parallel to the main surface of the substrate, and
the second electrode comprises multiple wiring pattern portions connected in series to one another, some of the multiple wiring pattern portions being in parallel to the predetermined direction, some of the multiple wiring pattern portions being perpendicular to the predetermined direction.

15. The gas detection device according to claim 1 , wherein the movable film structure is fixed to the substrate via an anchor support portion.

16. The gas detection device according to claim 15 , wherein the second film extends from the anchor support portion.

17. The gas detection device according to claim 1 , further comprising:
a first conductive portion on the substrate, the first conductive portion forming a first electrode of a variable capacitor; and
a second conductive portion forming a second electrode of the variable capacitor, the second electrode being connected to the movable film structure.

18. The gas detection device according to claim 17 , wherein the second electrode is connected to the first film of the movable film structure via an anchor connection portion.

19. The gas detection device according to claim 18 , wherein the first film has a cap structure.

20. The gas detection device according to claim 18 , further comprising:
a heating unit that heats the second film.

Assignees

• Toshiba Kk

Inventors

• Ikehashi Tamio
• Yamazaki Hiroaki

Classifications

• G01N33/0047 Primary

  Organic compounds · CPC title

• G01B7/22

  using change in capacitance · CPC title

• G01N33/005

  H2 · CPC title

• G01N33/0036 Primary

  specially adapted to detect a particular component (physical analysis of gaseous biological material G01N33/497) · CPC title