Gas sensor and gas sensing system

Patent metadata

Field	Value
Publication number	US-2018292347-A1
Application number	US-201816005995-A
Country	US
Kind code	A1
Filing date	Jun 12, 2018
Priority date	Dec 16, 2015
Publication date	Oct 11, 2018
Grant date	—

Abstract

A gas sensor includes: a cell array which includes a plurality of cells disposed in rows and columns; a read-out circuit which reads out signals from the plurality of cells; and a signal processor which processes the signals read out. Each of the plurality of cells includes: a gas molecule detector which is electrically isolated between adjacent ones of the plurality of cells; and an amplifier circuit which is electrically connected to the gas molecule detector.

First claim

What is claimed is:

1 . A gas sensor, comprising:
a cell array which includes a plurality of cells disposed in rows and columns; a read-out circuit which reads out signals from the plurality of cells; and a signal processor which processes the signals read out, wherein each of the plurality of cells includes: a gas molecule detector which is electrically isolated between adjacent ones of the plurality of cells; and an amplifier circuit which is electrically connected to the gas molecule detector.

2 . The gas sensor according to claim 1 ,
wherein each of the plurality of cells includes: a charge accumulation area which is electrically connected to the gas molecule detector; and a reset transistor which resets the charge accumulation area, and the amplifier circuit is an amplification transistor which amplifies electric charge accumulated in the charge accumulation area.

3 . The gas sensor according to claim 2 ,
wherein the gas molecule detector is disposed above the charge accumulation area, and is connected to the charge accumulation area by a contact plug which is conductive.

4 . The gas sensor according to claim 2 , further comprising:
a switch which electrically connects or isolates the gas molecule detector and the charge accumulation area.

5 . The gas sensor according to claim 4 ,
wherein the switch is a transfer transistor, and the gas molecule detector is disposed above the charge accumulation area, and is connected to a diffusion region of the transfer transistor by a contact plug which is conductive.

6 . The gas sensor according to claim 2 , further comprising:
a first control circuit which controls a power supply potential of the reset transistors in each of the columns in the cell array.

7 . The gas sensor according to claim 6 ,
wherein the first control circuit applies potentials having mutually different polarities between the gas molecule detectors of adjacent ones of the columns in the cell array.

8 . The gas sensor according to claim 6 ,
wherein the cell array includes a first region including at least one cell of the plurality of cells and a second region including cells other than the at least one cell, and the first control circuit applies potentials having mutually different polarities between (i) the gas molecule detector of the at least one cell in the first region and (ii) the gas molecule detectors of the cells in the second region.

9 . The gas sensor according to claim 2 , further comprising:
a first control circuit which controls a power supply potential of the reset transistor in each of the plurality of cells in the cell array.

10 . The gas sensor according to claim 9 ,
wherein the first control circuit applies potentials having mutually different polarities between the gas molecule detectors of adjacent ones of the plurality of cells in the cell array.

11 . The gas sensor according to claim 9 ,
wherein the cell array includes a first region including at least one cell of the plurality of cells and a second region including cells other than the at least one cell, and the first control circuit applies potentials having mutually different polarities between (i) the gas molecule detector of the at least one cell in the first region and (ii) the gas molecule detectors of the cells in the second region.

12 . The gas sensor according to claim 2 , further comprising:
a feedback amplifier circuit which supplies a feedback signal according to an output signal of the amplification transistor to a drain terminal of the reset transistor.

13 . The gas sensor according to claim 1 , further comprising:
a first electrode which is disposed above the gas molecule detector; and a second control circuit which controls a potential of the first electrode, wherein a region between the gas molecule detector and the first electrode is hollow.

14 . The gas sensor according to claim 13 , further comprising:
a second electrode which is disposed above the gas molecule detector, surrounds the first electrode in a plan view, and is electrically isolated from the first electrode.

15 . The gas sensor according to claim 14 ,
wherein a polarity of the potential of the first electrode differs from a polarity of a potential of the second electrode.

16 . The gas sensor according to claim 1 , further comprising:
an adsorbent which is disposed between adjacent ones of the gas molecule detectors, wherein a polarity of electric charge charged on a surface of the adsorbent differs from a polarity of the gas molecule detector.

17 . The gas sensor according to claim 1 , further comprising:
a catalyst which is disposed between adjacent ones of the gas molecule detectors, wherein the catalyst decomposes a predetermined gas molecule.

18 . A gas sensor, comprising:
a gas molecule detector; a charge accumulation area which is electrically connected to the gas molecule detector; a reset transistor which resets the charge accumulation area; and an amplification transistor which includes a gate that is electrically connected to the charge accumulation area.

19 . The gas sensor according to claim 18 ,
wherein the gas molecule detector is disposed above the charge accumulation area, and is connected to the charge accumulation area by a contact plug which is conductive.

20 . The gas sensor according to claim 19 , further comprising:
a switch which electrically connects or isolates the gas molecule detector and the charge accumulation area.

21 . The gas sensor according to claim 20 ,
wherein the switch is a transfer transistor, and the gas molecule detector is disposed above the charge accumulation area, and is connected to a diffusion region of the transfer transistor by a contact plug which is conductive.

22 . The gas sensor according to claim 18 , further comprising:
a feedback amplifier circuit which supplies a feedback signal according to an output signal of the amplification transistor to a drain terminal of the reset transistor.

23 . A gas sensing system, comprising:
the gas sensor according to claim 1 ; and a rectifier which generates a laminar flow, wherein the rectifier introduces gas molecules into the gas sensor.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Okino Toru
• Hirose Yutaka
• Kato Yoshihisa
• Oki Akio

Classifications

• G01N27/403 Primary

  Cells and electrode assemblies · CPC title

• G01N27/4148 Primary

  Integrated circuits therefor, e.g. fabricated by CMOS processing · CPC title

• G01N33/0031 Primary

  comprising two or more sensors, e.g. a sensor array · CPC title

• G01N27/4141

  specially adapted for gases · CPC title