Long wavelength infrared sensor and electronic device including the same

Patent metadata

Field	Value
Publication number	US-12339170-B2
Application number	US-202217836568-A
Country	US
Kind code	B2
Filing date	Jun 9, 2022
Priority date	Dec 31, 2021
Publication date	Jun 24, 2025
Grant date	Jun 24, 2025

Abstract

A long wavelength infrared sensor includes a first magnetoresistive unit; a second magnetoresistive unit; and a light absorption layer that absorbs light and emits heat, wherein the first magnetoresistive unit includes a first magnetoresistive element and a second magnetoresistive element electrically connected to each other, the second magnetoresistive unit includes a third magnetoresistive element and a fourth magnetoresistive element electrically connected to each other, the first and third magnetoresistive elements each have an antiparallel state of magnetization direction, the second and fourth magnetoresistive elements each have a parallel state of magnetization direction, and the first magnetoresistive element is electrically connected to the third magnetoresistive element by way of the second magnetoresistive element.

First claim

What is claimed is:

1. A long wavelength infrared sensor comprising:
a first magnetoresistive unit;
a second magnetoresistive unit; and
a light absorption layer that absorbs light and emits heat,
wherein the first magnetoresistive unit comprises a first magnetoresistive element and a second magnetoresistive element electrically connected to each other,
wherein the second magnetoresistive unit comprises a third magnetoresistive element and a fourth magnetoresistive element electrically connected to each other,
wherein the first magnetoresistive element and the third magnetoresistive element each have an antiparallel state of magnetization direction,
wherein the second magnetoresistive element and the fourth magnetoresistive element each have a parallel state of magnetization direction, and
wherein the first magnetoresistive element is electrically connected to the third magnetoresistive element by way of the second magnetoresistive element.

2. The long wavelength infrared sensor of claim 1 ,
wherein the first magnetoresistive element comprises a first lower magnetic layer, a first upper magnetic layer provided between the first lower magnetic layer and the light absorption layer, and a first tunneling barrier provided between the first lower magnetic layer and the first upper magnetic layer, and
wherein the second magnetoresistive element comprises a second lower magnetic layer, a second upper magnetic layer provided between the second lower magnetic layer and the light absorption layer, and a second tunneling barrier provided between the second lower magnetic layer and the second upper magnetic layer,
wherein a magnetization direction of the first upper magnetic layer is antiparallel to a magnetization direction of the first lower magnetic layer, and
wherein a magnetization direction of the second upper magnetic layer is parallel to a magnetization direction of the second lower magnetic layer.

3. The long wavelength infrared sensor of claim 2 , further comprising:
an upper conductive line electrically connecting the first upper magnetic layer to the second upper magnetic layer.

4. The long wavelength infrared sensor of claim 2 ,
wherein the first upper magnetic layer and the second upper magnetic layer each have a changeable magnetization direction, and
wherein the first lower magnetic layer and the second lower magnetic layer each have a fixed magnetization direction.

5. The long wavelength infrared sensor of claim 2 ,
wherein the first upper magnetic layer and the second upper magnetic layer each have a fixed magnetization direction, and
wherein the first lower magnetic layer and the second lower magnetic layer each have a changeable magnetization direction.

6. The long wavelength infrared sensor of claim 2 , further comprising:
a lower conductive line electrically connecting the first lower magnetic layer to the second lower magnetic layer.

7. The long wavelength infrared sensor of claim 1 , wherein the first magnetoresistive element and the third magnetoresistive element have an antiparallel state based on a reset signal passing through all of the first magnetoresistive element, the second magnetoresistive element, the third magneto resistive element, and the fourth magnetoresistive element, and
wherein the second magnetoresistive element and the fourth magnetoresistive element have a parallel state.

8. The long wavelength infrared sensor of claim 1 ,
wherein each of the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, and the fourth magnetoresistive elements comprises a lower magnetic layer, an upper magnetic layer provided between the lower magnetic layer and the light absorption layer, and a tunneling barrier layer provided between the lower magnetic layer and the upper magnetic layer,
wherein a magnetization direction of the upper magnetic layer is antiparallel to a magnetization direction of the lower magnetic layer in each of the first magnetoresistive element and the third magnetoresistive element, and
wherein a magnetization direction of the upper magnetic layer is parallel to a magnetization direction of the lower magnetic layer in each of the second magnetoresistive element and the fourth magnetoresistive element.

9. The long wavelength infrared sensor of claim 8 , further comprising:
a first upper conductive line electrically connecting the upper magnetic layer of the first magnetoresistive element to the upper magnetic layer of the second magnetoresistive element, and a second upper conductive line electrically connecting the upper magnetic layer of the third magnetoresistive element to the upper magnetic layer of the fourth magnetoresistive element; and
a lower conductive line electrically connecting the lower magnetic layer of the second magnetoresistive element to the lower magnetic layer of the third magnetoresistive element.

10. The long wavelength infrared sensor of claim 8 , further comprising:
a first lower conductive line electrically connecting the lower magnetic layer of the first magnetoresistive element to the lower magnetic layer of the second magnetoresistive element, and a second lower conductive line electrically connecting the lower magnetic layer of the third magnetoresistive element to the lower magnetic layer of the fourth magnetoresistive element; and
an upper conductive line electrically connecting the upper magnetic layer of the second magnetoresistive element to the upper magnetic layer of the third magnetoresistive element.

11. The long wavelength infrared sensor of claim 7 , wherein a distance between the first magnetoresistive unit and the second magnetoresistive unit is about 100 nanometers (nm) to about 3 micrometers (μm).

12. The long wavelength infrared sensor of claim 1 , wherein a thickness of the light absorption layer is about 3 μm to about 5 μm.

13. The long wavelength infrared sensor of claim 1 , further comprising a heat transfer via provided between the light absorption layer and the first magnetoresistive element.

14. The long wavelength infrared sensor of claim 13 ,
wherein the light absorption layer comprises a plurality of layers, and
wherein the heat transfer via and a lowermost layer of the plurality of layers of the light absorption layer form a single structure.

15. The long wavelength infrared sensor of claim 1 ,
wherein the light absorption layer is spaced apart from the first magnetoresistive element, and
wherein a separation distance between the light absorption layer and the first magnetoresistive element is about 1 μm or less.

16. The long wavelength infrared sensor of claim 1 , wherein the light absorption layer is in direct contact with the first magnetoresistive element.

17. The long wavelength infrared sensor of claim 1 , wherein a distance between the first magnetoresistive element and the second magnetoresistive element is about 100 nm to about 3 μm.

18. The long wavelength infrared sensor of claim 1 , further comprising a reflective layer provided on an opposite side of the light absorption layer with respect to the first magnetoresistive element and the second magnetoresistive element.

19. A long wavelength infrared sensor comprising:
a plurality of magnetoresistive units; and
a light absorption layer that absorbs light and emits heat,
wherein each of the plurality of magnetoresistive units comprises a first magnetoresistive element having an antiparallel state of magnetization direction and a second magnetoresistive element having a parallel state of magnet

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Jinmyoung
• Song Byonggwon
• Yang Yooseong
• Lee Duhyun
• Lee Byungkyu

Classifications

• G01J2005/202

  Arrays · CPC title

• H10N15/20

  Thermomagnetic devices using thermal change of the magnetic permeability, e.g. working above and below the Curie point · CPC title

• H10B61/00

  Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices · CPC title

• H10N50/10

  Magnetoresistive devices · CPC title

• G01J5/024

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