JP-2026075844-A - Electromagnetic wave detection element and electromagnetic wave sensor equipped therewith

Abstract

[Challenge] To improve the absorption efficiency of electromagnetic waves. [Solution] The electromagnetic wave detection element 11 has an electromagnetic wave detection unit 12. The electromagnetic wave detection unit 12 has a first surface 21 to which the electromagnetic wave to be measured is incident, a second surface 22 which is the back surface of the first surface 21, a temperature detection film 14 located between the first surface 21 and the second surface 22, a first conductive layer 15 connected to the temperature detection film 14, a dielectric layer 18 covering the first conductive layer 15 and the temperature detection film 14, and an overlapping portion 31 that overlaps the temperature detection film 14 and the first conductive layer 15 when viewed in the film thickness direction of the temperature detection film 14. In the overlapping portion 31, the average thickness Z1 of the dielectric layer 18 between the first conductive layer 15 and the first surface 21 is greater than the average distance Z2 in the film thickness direction between the first conductive layer 15 and the second surface 22. [Selection Diagram] Figure 4

Inventors

• 青木 進
• 原 晋治
• 太田 尚城
• 中川 貴大

Assignees

• ＴＤＫ株式会社

Dates

Publication Date

20260511

Application Date

20241023

Claims (13)

1. It has an electromagnetic wave detection unit, The electromagnetic wave detection unit is The first surface into which the electromagnetic wave to be measured is incident, The second surface is the back surface of the first surface, A temperature sensing film located between the first surface and the second surface, A first conductive layer connected to the temperature sensing film, A dielectric layer covering the first conductive layer and the temperature sensing film, The temperature sensing film has an overlapping portion that overlaps the temperature sensing film and the first conductive layer when viewed in the film thickness direction of the temperature sensing film, An electromagnetic wave detection element wherein, in the superimposed portion, the average thickness of the dielectric layer between the first conductive layer and the first surface is greater than the average distance in the film thickness direction between the first conductive layer and the second surface.
2. It has an arm portion that supports the electromagnetic wave detection unit, The electromagnetic wave detection element according to claim 1, wherein the average thickness of the arm portion is smaller than the average thickness of the electromagnetic wave detection portion.
3. The arm portion has a first arm surface located on the incident side of the electromagnetic wave, and a second arm surface which is the back surface of the first arm surface. The electromagnetic wave detection element according to claim 2, wherein a part of the electromagnetic wave detection unit protrudes from the second arm surface in a direction toward the second arm surface from the first arm surface.
4. The arm portion has a first arm surface located on the incident side of the electromagnetic wave, and a second arm surface which is the back surface of the first arm surface. The electromagnetic wave detection element according to claim 2, wherein a part of the electromagnetic wave detection unit protrudes from the first arm surface in a direction toward the first arm surface from the second arm surface.
5. It has an arm portion that supports the electromagnetic wave detection unit, The arm portion has a second conductive layer electrically connected to the first conductive layer, and a dielectric layer covering the second conductive layer on the incident side of the electromagnetic wave. The electromagnetic wave detection element according to claim 1, wherein the average thickness of the dielectric layer between the first conductive layer and the first surface in the superimposed portion is greater than the average thickness of the dielectric layer in the arm portion.
6. The arm portion supporting the electromagnetic wave detection unit, A substrate provided facing the first surface in the film thickness direction and away from the first surface, A support column connecting the substrate and the arm portion, An electromagnetic wave detection element according to claim 1, having the following characteristics.
7. It has another first conductive layer connected to the temperature sensing film, The temperature sensing film includes an electromagnetic wave incident surface facing the first surface, The electromagnetic wave detection element according to any one of claims 1 to 6, wherein the first conductive layer and the other first conductive layer are connected to the electromagnetic wave incident surface.
8. It has a back-side conductive layer connected to the temperature sensing film, The temperature sensing film includes an electromagnetic wave incident surface facing the first surface, The electromagnetic wave detection element according to any one of claims 1 to 6, wherein the first conductive layer is connected to the electromagnetic wave incident surface, and the back conductive layer is connected to the back surface of the electromagnetic wave incident surface.
9. The electromagnetic wave detection element according to any one of claims 1 to 6, wherein the dielectric layer comprises two or more types of dielectric films.
10. The electromagnetic wave detection element according to claim 9, wherein the dielectric layer comprises an aluminum oxide film and a silicon oxide film.
11. The electromagnetic wave detection element according to claim 10, wherein the silicon oxide film is provided between the aluminum oxide film and the temperature detection film, in contact with the temperature detection film.
12. An electromagnetic wave sensor comprising an electromagnetic wave detection element according to any one of claims 1 to 6.
13. A plurality of electromagnetic wave detection elements according to any one of claims 1 to 5 are provided, The electromagnetic wave sensor comprises multiple electromagnetic wave detection elements arranged in an array.

Description

This disclosure relates to an electromagnetic wave detection element and an electromagnetic wave sensor equipped therewith. Electromagnetic wave sensors that detect electromagnetic waves such as infrared radiation are known. Patent Document 1 describes an electromagnetic wave sensor comprising a temperature sensing element, a conductive layer electrically connected to the electromagnetic wave incident surface of the temperature sensing element, and a dielectric layer covering the temperature sensing element and the conductive layer. The temperature sensing element has a thermistor film whose electrical resistance changes according to temperature. The thermistor film undergoes a temperature change due to electromagnetic waves incident from the outside. There is a correlation (Stefan-Boltzmann law) between the temperature of the object being measured and the radiant energy emitted from that object. Based on this principle, the temperature of the object can be measured from the electrical resistance of the thermistor film. Japanese Patent Publication No. 2023-33862 This is an exploded perspective view of the infrared sensor according to the first embodiment.This is a schematic diagram of an electromagnetic wave detection element according to the first embodiment.Figure 2 is a schematic plan view of the electromagnetic wave detection element shown.Figure 2 is a schematic cross-sectional view of the electromagnetic wave detection element shown.This is a schematic cross-sectional view of an electromagnetic wave detection element in a comparative example.This is a schematic cross-sectional view showing other configurations of the dielectric layer.Figure 2 is a schematic cross-sectional view showing a manufacturing method for the electromagnetic wave detection element shown.This is a schematic plan view of an electromagnetic wave detection element according to the second embodiment.Figure 8 is a schematic cross-sectional view of the electromagnetic wave detection element shown.This is a schematic cross-sectional view showing other configurations of the dielectric layer.Figure 8 is a schematic cross-sectional view showing a manufacturing method for the electromagnetic wave detection element.This is a schematic cross-sectional view of a modified electromagnetic wave detection element.This is a schematic cross-sectional view of another modified electromagnetic wave detection element. Several embodiments of the electromagnetic wave detection element and electromagnetic wave sensor of this disclosure will be described below with reference to the drawings. In the following description and drawings, the X and Y directions are parallel to the main surfaces of the first substrate 2 and the second substrate 3, the X direction corresponds to the row direction of the array of electromagnetic wave detection elements 11, and the Y direction corresponds to the column direction of the array of electromagnetic wave detection elements 11. The main surfaces are the mutually opposing surfaces of the first substrate 2 and the second substrate 3. The X and Y directions are orthogonal to each other. The Z direction is orthogonal to the X and Y directions and is perpendicular to the main surfaces of the first substrate 2 and the second substrate 3, or the thickness direction of the temperature detection film 14 of the electromagnetic wave detection element 11. The +Z direction is the direction from the second substrate 3 toward the first substrate 2, or the direction from the first arm surface 24 of the arm portion 13 toward the second arm surface 25. The Z-direction is the direction from the first substrate 2 to the second substrate 3, or the direction from the second arm surface 25 of the arm portion 13 to the first arm surface 24. For convenience, the perspective views and cross-sectional views from Figure 2 onward are shown upside down compared to Figure 1. The following embodiments focus on infrared sensors in which electromagnetic wave detection elements 11 are arranged in a two-dimensional array. Infrared sensors primarily detect long-wavelength infrared radiation. The wavelength of long-wavelength infrared radiation is generally 8 to 14 μm. Such infrared sensors are mainly used as image sensors in infrared cameras. Infrared cameras can be used as night vision scopes and goggles in dark places, as well as for measuring the temperature of people and objects. Furthermore, infrared sensors in which multiple electromagnetic wave detection elements 11 are arranged in a one-dimensional array can be used as sensors for measuring various temperatures or temperature distributions. Although not explained in detail, infrared sensors in which multiple electromagnetic wave detection elements 11 are arranged in a one-dimensional array are also included within the scope of this disclosure. The electromagnetic waves to be detected are not limited to infrared radiation; for example, terahertz waves with wavelengths of 100 μm to 1 mm may also be det