Infrared sensor and phononic crystal

Patent metadata

Field	Value
Publication number	US-10890489-B2
Application number	US-201916566868-A
Country	US
Kind code	B2
Filing date	Sep 10, 2019
Priority date	May 22, 2018
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

An infrared sensor according to the present disclosure includes base substrate, infrared receiver, and beam. The beam includes connective portion connecting with the base substrate and/or a member on the base substrate, and separated portion separated from the base substrate. The infrared receiver and the beam are joined with each other at the separated portion. The infrared receiver is supported by the beam in a state where the infrared receiver is separated from the base substrate. The beam includes junction part joined to the infrared receiver, and section positioned between junction part and the connective portion, and section includes a phononic crystal structure defined by a plurality of through holes orderly arranged. The crystal structure includes a first domain and a second domain that are phononic crystal domains. The first domain includes, in a plan view, a plurality of through holes arranged orderly in a first direction, while the second domain includes, in a plan view, a plurality of through holes arranged orderly in a second direction that is different from the first direction. The infrared sensor according to the present disclosure has enhanced responsivity.

First claim

The invention claimed is:

1. An infrared sensor comprising:
a base substrate;
an infrared receiver; and
a beam,
wherein
the beam includes a connective portion connecting with the base substrate and/or a member on the base substrate, and a separated portion separated from the base substrate,
the infrared receiver and the beam are joined with each other at the separated portion,
the infrared receiver is supported by the beam including the separated portion in a state where the infrared receiver is separated from the base substrate,
the beam includes a junction part joined to the infrared receiver, and a section positioned between the junction part and the connective portion includes a phononic crystal structure defined by a plurality of through holes orderly arranged,
the phononic crystal structure includes a first domain and a second domain that are phononic crystal domains,
the first domain includes, in a plan view, the plurality of through holes arranged orderly in a first direction,
the second domain includes, in a plan view, the plurality of through holes arranged orderly in a second direction that is different from the first direction,
the infrared receiver is a thermopile infrared receiver or a bolometer infrared receiver,
if the infrared receiver is the thermopile infrared receiver,
the beam includes a first region having a first Seebeck coefficient, a second region having a second Seebeck coefficient that is different from the first Seebeck coefficient, and a junction region in which the first region and the second region are joined with each other, and
the infrared receiver and the junction region of the beam are joined with each other, and

if the infrared receiver is the bolometer infrared receiver, the infrared sensor further comprises:
a first wiring and a second wiring being both electrically connected to the infrared receiver;
a first signal processing circuit electrically connected to the first wiring; and
a second signal processing circuit electrically connected to the second wiring.

2. The infrared sensor according to claim 1 , wherein:
the infrared receiver is the thermopile infrared receiver; and
the beam is a single layer.

3. The infrared sensor according to claim 1 , wherein:
the infrared receiver is the thermopile infrared receiver;
the beam includes a base layer and a thermocouple layer disposed on the base layer; and
the thermocouple layer includes the first region, the second region, and the junction region.

4. The infrared sensor according to claim 1 , wherein:
the infrared receiver is the thermopile infrared receiver; and
the infrared sensor further comprises:
a first wiring electrically connected to the first region;
a second wiring electrically connected to the second region;
a first signal processing circuit electrically connected to the first wiring; and
a second signal processing circuit electrically connected to the second wiring.

5. The infrared sensor according to claim 1 , wherein:
the infrared receiver is the bolometer infrared receiver;
each of the first wiring and the second wiring includes a separated section separated from the base substrate in between a part connecting with the infrared receiver and corresponding one of the first signal processing circuit and the second signal processing circuit; and
the separated section of the first wiring and/or the separated section of the second wiring includes the phononic crystal structure.

6. The infrared sensor according to claim 1 , wherein:
the infrared receiver is the bolometer infrared receiver;
each of the first wiring and the second wiring includes a separated section separated from the base substrate in between a part connecting with the infrared receiver and corresponding one of the first signal processing circuit and the second signal processing circuit; and
the separated section of the first wiring and/or the separated section of the second wiring is in contact with a surface of the beam.

7. The infrared sensor according to claim 6 , wherein:
the separated section of the first wiring and/or the separated section of the second wiring includes the phononic crystal structure; and
the plurality of through holes of the phononic crystal structure of the beam are common to the phononic crystal structure of the first wiring and/or the phononic crystal structure of the second wiring.

8. The infrared sensor according to claim 1 , wherein:
the beam includes the connective portion at each of two ends of the beam; and
the infrared receiver and the beam are joined with each other between the two ends of the beam.

9. The infrared sensor according to claim 1 , wherein:
the beam includes the connective portion at one end of the beam; and
the infrared receiver and the beam are joined with each other at another end of the beam.

10. The infrared sensor according to claim 1 , wherein:
the base substrate includes a recess;
the recess is positioned between the base substrate and the infrared receiver with the beam; and
the infrared receiver and the beam are suspended above the recess of the base substrate in a sectional view.

11. The infrared sensor according to claim 1 , further comprising a support on the base substrate, the support extending in a direction away from an upper surface of the base substrate,
wherein the beam connects with the support at the connective portion, and
the infrared receiver and the beam are suspended above the base substrate by the support in a sectional view.

12. The infrared sensor according to claim 1 , wherein a periodicity with which the plurality of through holes are arranged in the first domain is equal to a periodicity with which the plurality of through holes are arranged in the second domain.

13. The infrared sensor according to claim 1 , wherein the plurality of through holes orderly arranged in the first domain are equal in diameter to the plurality of through holes orderly arranged in the second domain.

14. The infrared sensor according to claim 1 , wherein unit lattices formed by the plurality of through holes orderly arranged in the first domain and unit lattices formed by the plurality of through holes orderly arranged in the second domain are identical in type.

15. The infrared sensor according to claim 1 , wherein the first domain and the second domain are different in shape in a plan view.

16. The infrared sensor according to claim 1 , wherein in a plan view, an interface between the first domain and the second domain that are adjacent to each other extends, in the section, in a direction inclined relative to a direction along a width of the beam.

17. The infrared sensor according to claim 1 , wherein in a plan view, an interface between the first domain and the second domain that are adjacent to each other includes a bend.

18. The infrared sensor according to claim 1 , wherein the first domain and/or the second domain of the phononic crystal structure does not border a side of the beam.

19. A phononic crystal having a phononic crystal structure, the phononic crystal comprising a first domain and a second domain that are phononic crystal domains,
wherein the first domain is defined by a plurality of through holes arranged orderly in a first direction in a plan view, and
the second domain is defined by a plurality of through holes orderly arranged, in a plan view, in a second direction that is different from the first direction.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Tambo Naoki
• Takahashi Kouhei
• Kawasaki Takashi
• Nakamura Kunihiko
• Fujikane Masaki
• Naito Yasuyuki

Classifications

• G01J5/34

  using capacitors, e.g. pyroelectric capacitors · CPC title

• G01J5/20 Primary

  using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices · CPC title

• G01J5/024

  Special manufacturing steps or sacrificial layers or layer structures · CPC title

• G01J5/0853 Primary

  having infrared absorbers other than the usual absorber layers deposited on infrared detectors like bolometers, wherein the heat propagation between the absorber and the detecting element occurs within a solid · CPC title

• G01J5/0205

  Mechanical elements; Supports for optical elements · CPC title