INFRARED DETECTION DEVICE

• US 20150168222A1
• Filed: 06/07/2013
• Published: 06/18/2015
• Est. Priority Date: 06/18/2012
• Status: Abandoned Application

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Noda, Toshinari
• Application Number:
  US14/404,492
• Publication Number:
  US 20150168222A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01J 2005/345 Arrays
• CPC Class Codes: G01J 5/023 Particular leg structure or construction or shape; Nanotubes
• CPC Class Codes: G01J 5/024 Special manufacturing steps or sacrificial layers or layer structures
• CPC Class Codes: G01J 5/046 Materials; Selection of thermal materials
• CPC Class Codes: G01J 5/0853 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 Class Codes: G01J 5/34 using capacitors, e.g. pyroelectric capacitors
• CPC Class Codes: H10N 15/10 Thermoelectric devices using thermal change of the dielectric constant, e.g. working above and below the Curie point

Abstract

An infrared detection device includes a substrate and a heat-type light sensing element. The substrate has a recess, and a frame positioned around the recess. The heat-type light sensing element has a leg and a sensing unit, and the leg is connected onto the frame so that the sensing unit is positioned over the recess. The heat-type light sensing element includes an intermediate layer provided on the substrate, a first electrode layer provided on the intermediate layer, a sensing layer provided on the first electrode layer, and a second electrode layer provided on the sensing layer. The substrate has a linear thermal expansion coefficient larger than that of the sensing layer. The intermediate layer has a linear thermal expansion coefficient decreasing toward the first electrode layer from the substrate.

Claims

1. An infrared detection device comprising:

a substrate provided with a recess and including a frame positioned around the recess; and

a heat-type light sensing element including a sensing unit and a leg connected onto the frame so that the sensor unit is positioned over the recess, the heat-type light sensing element also including an intermediate layer provided on the substrate, a first electrode layer provided on the intermediate layer, a sensing layer provided on the first electrode layer, and a second electrode layer provided on the sensing layer,

wherein the substrate has a linear thermal expansion coefficient larger than a linear thermal expansion coefficient of the sensing layer, and

wherein the intermediate layer has a linear thermal expansion coefficient decreasing toward the first electrode layer from the substrate.

2. The infrared detection device according to claim 1,

wherein one of a polarization amount and capacitance of the sensing layer changes according to temperature change.

3. The infrared detection device according to claim 1,

wherein the substrate is formed of a material capable of reflecting infrared rays.

4. The infrared detection device according to claim 3,

wherein the substrate is formed of a metallic material.

5. The infrared detection device according to claim 4,

wherein the substrate is formed of a rolled steel plate having a minute metallic structure, and

wherein the metallic structure has a diameter smaller than a diameter of the sensing layer that is circular in a top view, and has a diameter smaller than a length of a short side of the sensing layer that is square in a top view.

6. The infrared detection device according to claim 1,

wherein two or more elements contained in the substrate diffuse in the intermediate layer.

7. The infrared detection device according to claim 6,

wherein the intermediate layer has gradients of diffusion amounts of the two or more elements contained in the substrate, the gradients being different from each other.

8. The infrared detection device according to claim 7,

wherein the substrate is formed of a metallic material containing iron and chrome, and

wherein the intermediate layer is formed by diffusion of iron and chrome contained in the substrate.

9. The infrared detection device according to claim 6,

wherein the intermediate layer is formed of silicon oxide.

10. The infrared detection device according to claim 1,

wherein the heat-type light sensing element is provided on the second electrode layer and further has a constrained layer with a linear thermal expansion coefficient smaller than the linear thermal expansion coefficient of the sensing layer.

11. The infrared detection device according to claim 10,

wherein the constrained layer is formed a material capable of absorbing infrared rays, and

wherein the second electrode layer is formed a material capable of reflecting infrared rays.

12. The infrared detection device according to claim 11,

wherein expression (1) is satisfied where “

d”

is a thickness of the constrained layer, “

n”

is a refractive index of the constrained layer, “

λ

”

is a wavelength of infrared rays as a detection target, and “

m”

is 0 or a natural number.

n×

d=(2m+1)×

λ

/4  

 

(1)

13. The infrared detection device according to claim 1,

wherein the second electrode layer is formed of a material capable of absorbing infrared rays.

14. The infrared detection device according to claim 1,

wherein the first electrode layer is formed of a perovskite oxide having electric conductivity, and

wherein a ratio of a difference between a lattice constant of a main orientation plane of the first electrode layer and a lattice constant of a main orientation plane of the sensing layer, with respect to the lattice constant of the main orientation plane of the sensing layer falls within ±

10%.