JP2022121368A - Photodetector, receiver and photo sensor device - Google Patents

Abstract

To provide a light detection element making a good response to light, a receiving device and an optical sensor device.SOLUTION: A light detection element 100 has a magnetic element 10 comprising a first ferromagnetic layer 1, a second ferromagnetic layer 2, and a spacer layer 3 sandwiched between the first ferromagnetic layer 1 and second ferromagnetic layer 2. The first ferromagnetic layer 1 is irradiated with light L from a direction crossing a laminating direction of the magnetic element 10.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a photodetector, a receiver, and a photosensor device.

Photoelectric conversion elements are used in various applications.

For example, Patent Literature 1 describes a receiver that receives an optical signal using a photodiode. A photodiode is, for example, a pn-junction diode using a semiconductor pn-junction, and converts light into an electric signal.

Further, for example, Patent Document 2 describes an optical sensor using a semiconductor pn junction and an image sensor using this optical sensor.

Japanese Patent Application Laid-Open No. 2001-292107 U.S. Pat. No. 9,842,874

A photodetector using a semiconductor pn junction is widely used, but a new photodetector is required for further development. Further, the photodetector converts light into an electrical signal, and an improvement in conversion accuracy is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photodetector, a receiver, and an optical sensor device that are highly responsive to light.

In order to solve the above problems, the following means are provided.

(1) The photodetector according to the first aspect includes a first ferromagnetic layer, a second ferromagnetic layer, a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and the first ferromagnetic layer is irradiated with light from a direction crossing the lamination direction of the magnetic element.

(2) The photodetector element according to the above aspect further includes a first electrode and a second electrode sandwiching the magnetic element in the stacking direction, and at least one side surface of the first electrode and the second electrode and the side surface of the magnetic element are in contact with the same imaginary plane at least partially, and the first ferromagnetic layer may be irradiated with the light from the imaginary plane side.

(3) In the photodetecting element according to the above aspect, a part of the side surface of the magnetic element may be a flat surface, and the flat surface may be irradiated with the light.

(4) In the photodetector element according to the aspect described above, a part of the side surface of the magnetic element may be a flat surface, and the flat surface may be in contact with the virtual plane.

(5) The photodetector according to the above aspect may further include an oxide film that covers the flat surface and allows the light to pass therethrough.

(6) The photodetecting element according to the above aspect further includes a heat-generating portion, and the heat-generating portion is located behind the magnetic element in a light irradiation direction in which the light is mainly irradiated to the magnetic element. good too.

(7) The photodetecting element according to the above aspect further includes an expanding section, the heat generating section is located at a position capable of heating the expanding section, and the expanding section mainly irradiates the magnetic element with the light. The expanding portion may be located behind the magnetic element in the light irradiation direction, and may have a linear thermal expansion coefficient larger than that of the first ferromagnetic layer.

(8) In the photodetecting element according to the above aspect, the light may be light containing a high-frequency optical signal and varying in intensity.

(9) In the photodetector according to the above aspect, the light may be light that has passed through a wavelength filter.

(10) A receiver according to a second aspect has the photodetector element according to the above aspect.

(11) A photosensor device according to a third aspect has the photosensing element according to the above aspect.

The photodetecting element, the receiving device, and the photosensor device according to the above aspect have good responsiveness to light.

1 is a perspective view of a photodetector element according to a first embodiment; FIG. 1 is a cross-sectional view of a photodetector element according to a first embodiment; FIG. 1 is a plan view of a photodetector element according to a first embodiment; FIG. FIG. 5 is a diagram for explaining the first mechanism of the first operation example of the photodetector according to the first embodiment; FIG. 10 is a diagram for explaining the second mechanism of the first operation example of the photodetector according to the first embodiment; FIG. 10 is a diagram for explaining the first mechanism of the second operation example of the photodetector according to the first embodiment; FIG. 10 is a diagram for explaining the second mechanism of the second operation example of the photodetector according to the first embodiment; FIG. 10 is a diagram for explaining another example of the second operation example of the photodetector according to the first embodiment; FIG. 10 is a diagram for explaining another example of the second operation example of the photodetector according to the first embodiment; FIG. 10 is a cross-sectional view of a photodetector according to a first modified example; FIG. 11 is a cross-sectional view of a photodetector element according to a second modified example; FIG. 11 is a cross-sectional view of a photodetector according to a third modified example; FIG. 11 is a cross-sectional view of a photodetector according to a fourth modified example; FIG. 5 is a cross-sectional view of a photodetector element according to a second embodiment; FIG. 11 is a cross-sectional view of a photodetector element according to a third embodiment; It is a cross-sectional view of a photodetector element according to a fourth embodiment. 1 is a block diagram of a transmitting/receiving device according to a first application example; FIG. 1 is a conceptual diagram of an example of a communication system; FIG. FIG. 11 is a conceptual diagram of a cross section of an optical sensor device according to a second application example; 1 is a schematic diagram of an example of a terminal device; FIG.

Hereinafter, embodiments will be described in detail with appropriate reference to the drawings. In the drawings used in the following description, characteristic parts may be shown enlarged for convenience in order to make the characteristics easier to understand, and the dimensional ratio of each component may differ from the actual one. The materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited to them, and can be implemented with appropriate modifications within the scope of the present invention.

Define direction. The stacking direction of the magnetic element 10 is the z-direction, one direction in the plane perpendicular to the z-direction is the x-direction, and the direction perpendicular to the x-direction and the z-direction is the y-direction. The z-direction is an example of the lamination direction. Hereinafter, the +z direction may be expressed as “up” and the −z direction as “down”. The +z direction is the direction from the second ferromagnetic layer 2 toward the first ferromagnetic layer 1 . Up and down do not necessarily match the direction in which gravity is applied.

"First Embodiment"
FIG. 1 is a perspective view of a photodetector element 100 according to the first embodiment. FIG. 2 is a yz cross-sectional view of the photodetector 100 according to the first embodiment. FIG. 3 is a plan view of the photodetector 100 according to the first embodiment as seen from the z direction.

The photodetector 100 converts the state or state change of the irradiated light L into an electrical signal. The light L in this specification includes not only visible light but also infrared rays having longer wavelengths than visible rays and ultraviolet rays having shorter wavelengths than visible rays. The wavelength of visible light is, for example, 380 nm or more and less than 800 nm. The wavelength of infrared rays is, for example, 800 nm or more and 1 mm or less. The wavelength of ultraviolet rays is, for example, 200 nm or more and less than 380 nm.

The photodetector element 100 has, for example, a magnetic element 10, a first electrode 20, a second electrode 30, a light irradiation section 40, and an insulating layer 50. As shown in FIG.

The light irradiation section 40 is, for example, a section from which the light L propagated from the light source is emitted. The light L emitted from the light irradiation section 40 is irradiated onto the side surface 10 s of the magnetic element 10 . The light irradiation section 40 faces the side surface 10s of the magnetic element 10, for example.

The light L is applied to the magnetic element 10 from a direction crossing the z-direction. The light L is applied to the side surface 10s of the magnetic element 10 from the y direction, for example. Hereinafter, the direction in which the magnetic element 10 is mainly irradiated with light is referred to as the light irradiation direction. Being irradiated mainly means that the intensity of the light irradiated from that direction is higher than the intensity of the light irradiated from other directions. In FIGS. 1 and 2, the y direction is the light irradiation direction with respect to the magnetic element 10 . The light L is, for example, light containing a high-frequency optical signal and varying in intensity, or light that has passed through a wavelength filter and has its wavelength range controlled. A high-frequency optical signal is, for example, a signal having a frequency of 100 MHz or higher.

The first electrode 20 contacts the first surface of the magnetic element 10 . The first surface is the surface of the magnetic element 10 on the first ferromagnetic layer 1 side in the z direction. The second electrode 30 contacts the second surface of the magnetic element 10 . The second surface is the surface of the magnetic element 10 on the second ferromagnetic layer 2 side in the z direction. The first electrode 20 and the second electrode 30 sandwich the magnetic element 10 in the z direction, for example.

The first electrode 20 and the second electrode 30 are made of a conductive material. The first electrode 20 and the second electrode 30 are made of metal such as Cu, Al, Au or Ru, for example. Ta or Ti may be stacked above and below these metals. As the first electrode 20 and the second electrode 30, a laminated film of Cu and Ta, a laminated film of Ta, Cu and Ti, and a laminated film of Ta, Cu and TaN may be used. Alternatively, TiN or TaN may be used as the first electrode 20 and the second electrode 30 .

The first electrode 20 and the second electrode 30 may be transparent to the wavelength range of light with which the magnetic element 10 is irradiated. For example, the first electrode 20 and the second electrode 30 include oxide transparent electrode materials such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium gallium zinc oxide (IGZO). A transparent electrode may be used. Also, the first electrode 20 and the second electrode 30 may be configured to have a plurality of columnar metals in these transparent electrode materials.

The insulating layer 50 is between the first electrode 20 and the second electrode 30 . The insulating layer 50 covers, for example, the portion of the magnetic element 10 excluding the side surface 10s to which the light L is irradiated. The insulating layer 50 is an interlayer insulating film. The insulating layer 50 is, for example, an oxide, nitride, or oxynitride of Si, Al, or Mg. The insulating layer 50 is made of, for example, silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO _x ), and the like.

When the state of the irradiated light L changes, the magnetic element 10 changes its resistance value in the z-direction according to the change in the state of the light L. FIG. When the state of the light L applied to the magnetic element 10 changes, the output voltage from the magnetic element 10 changes according to the change in the state of the light L. FIG. The magnetic element 10 has a first ferromagnetic layer 1, a second ferromagnetic layer 2 and a spacer layer 3, for example. A spacer layer 3 is located between the first ferromagnetic layer 1 and the second ferromagnetic layer 2 . The magnetic element 10 may have other layers besides these.

A part of the side surface of the magnetic element 10 is irradiated with light. For example, the side surface 10s is illuminated with light. The side surface 10s is the side surface of the magnetic element 10 that is mainly irradiated with the light L. As shown in FIG. The intensity of the light applied to the side surface 10s is greater than the intensity of the light applied to the other side surfaces. 10 s of side surfaces are light-receiving surfaces of the light L, for example.

A part of the side surface of the magnetic element 10 is a flat surface. For example, the side surface 10s is a flat surface. For example, the side surface 10s, which is a flat surface, is irradiated with the light L.

A side surface of the magnetic element 10 and a side surface of at least one of the first electrode 20 and the second electrode 30 are at least partially in contact with the same virtual plane VS. The virtual plane VS is one of the planes tangential to the sides of the magnetic element 10 . The light L is applied to the first ferromagnetic layer 1 from the virtual plane VS side.

For example, the side surface 10s, the side surface 20s of the first electrode 20, and the side surface 30s of the second electrode 30 are in contact with the same virtual plane VS. The side 10s, the side 20s, and the side 30s are continuous. The side surface 20s is the side surface of the first electrode 20 that is mainly irradiated with the light L. As shown in FIG. The side surface 30s is the side surface of the second electrode 30 that is mainly irradiated with the light L. As shown in FIG.

The magnetic element 10 is, for example, an MTJ (Magnetic Tunnel Junction) element in which the spacer layer 3 is made of an insulating material. In this case, the magnetic element 10 has a resistance value in the z direction (current is resistance value) changes. Such an element is also called a magnetoresistive element.

The first ferromagnetic layer 1 is a photodetection layer whose magnetization state changes when light is irradiated from the outside. The first ferromagnetic layer 1 is also called a magnetization free layer. The magnetization free layer is a layer containing a magnetic material whose magnetization state changes when a predetermined external force is applied. The predetermined external force is, for example, light L irradiated from the outside, a current flowing in the z-direction of the magnetic element 10, or an external magnetic field. The magnetization state of the first ferromagnetic layer 1 changes depending on the intensity of the light L with which the first ferromagnetic layer 1 is irradiated.

The first ferromagnetic layer 1 contains a ferromagnetic material. The first ferromagnetic layer 1 contains at least one of magnetic elements such as Co, Fe or Ni, for example. The first ferromagnetic layer 1 may contain non-magnetic elements such as B, Mg, Hf and Gd together with the magnetic elements as described above. The first ferromagnetic layer 1 may be, for example, an alloy containing a magnetic element and a non-magnetic element. The first ferromagnetic layer 1 may be composed of a plurality of layers. The first ferromagnetic layer 1 is, for example, a CoFeB alloy, a laminate in which a CoFeB alloy layer is sandwiched between Fe layers, or a laminate in which a CoFeB alloy layer is sandwiched between CoFe layers.

The first ferromagnetic layer 1 is an in-plane magnetization film having an easy axis of magnetization in the in-plane direction (either direction in the xy plane), or perpendicular magnetization having an easy axis of magnetization in the direction perpendicular to the plane (z direction). It may be a membrane.

The film thickness of the first ferromagnetic layer 1 is, for example, 1 nm or more and 5 nm or less. The film thickness of the first ferromagnetic layer 1 is preferably, for example, 1 nm or more and 2 nm or less. When the first ferromagnetic layer 1 is a perpendicularly magnetized film, if the film thickness of the first ferromagnetic layer 1 is small, the effect of applying perpendicular magnetic anisotropy from the layers above and below the first ferromagnetic layer 1 is enhanced. 1 The perpendicular magnetic anisotropy of the ferromagnetic layer 1 increases. That is, when the perpendicular magnetic anisotropy of the first ferromagnetic layer 1 is high, the force that causes the magnetization M1 to return to the z-direction increases. On the other hand, when the film thickness of the first ferromagnetic layer 1 is large, the effect of applying perpendicular magnetic anisotropy from the layers above and below the first ferromagnetic layer 1 is relatively weakened, and the perpendicular magnetic field of the first ferromagnetic layer 1 is reduced. Anisotropy weakens.

If the film thickness of the first ferromagnetic layer 1 becomes thinner, the volume of the ferromagnetic body becomes smaller, and if it becomes thicker, the volume of the ferromagnetic body becomes larger. The magnetization responsiveness of the first ferromagnetic layer 1 when external energy is applied is given by the product (KuV) of the magnetic anisotropy (Ku) and the volume (V) of the first ferromagnetic layer 1. inversely proportional. That is, when the product of the magnetic anisotropy and the volume of the first ferromagnetic layer 1 decreases, the reactivity to light increases. From this point of view, in order to enhance the response to light, it is preferable to appropriately design the magnetic anisotropy of the first ferromagnetic layer 1 and then reduce the volume of the first ferromagnetic layer 1 .

When the film thickness of the first ferromagnetic layer 1 is thicker than 2 nm, an insertion layer made of, for example, Mo and W may be provided in the first ferromagnetic layer 1 . That is, the first ferromagnetic layer 1 may be a laminate in which a ferromagnetic layer, an insertion layer, and a ferromagnetic layer are sequentially stacked in the z-direction. Perpendicular magnetic anisotropy of the entire first ferromagnetic layer 1 increases due to interfacial magnetic anisotropy at the interface between the insertion layer and the ferromagnetic layer. The film thickness of the insertion layer is, for example, 0.1 nm to 0.6 nm.

The second ferromagnetic layer 2 is a magnetization fixed layer. The magnetization fixed layer is a layer made of a magnetic material whose magnetization state is less likely to change than the magnetization free layer when a predetermined external energy is applied. For example, the magnetization direction of the magnetization fixed layer is less likely to change than the magnetization direction of the magnetization free layer when a predetermined external energy is applied. Further, for example, the magnetization fixed layer is less likely to change in magnitude of magnetization than the magnetization free layer when a predetermined external energy is applied. The coercive force of the second ferromagnetic layer 2 is, for example, greater than the coercive force of the first ferromagnetic layer 1 . The second ferromagnetic layer 2 has an easy magnetization axis in the same direction as the first ferromagnetic layer 1, for example. The second ferromagnetic layer 2 may be an in-plane magnetization film or a perpendicular magnetization film.

The material constituting the second ferromagnetic layer 2 is, for example, the same as that of the first ferromagnetic layer 1 . The second ferromagnetic layer 2 is, for example, 0.4 nm to 1.0 nm thick Co, 0.1 nm to 0.5 nm thick Mo, 0.3 nm to 1.0 nm thick CoFeB alloy, 0.3 nm thick. A laminated body in which Fe layers having a thickness of up to 1.0 nm are sequentially laminated may be used.

The magnetization of the second ferromagnetic layer 2 may be fixed by magnetic coupling with the third ferromagnetic layer via a magnetic coupling layer, for example. In this case, the combination of the second ferromagnetic layer 2, the magnetic coupling layer and the third ferromagnetic layer may be called a fixed magnetization layer.

The third ferromagnetic layer is magnetically coupled with the second ferromagnetic layer 2, for example. Magnetic coupling is, for example, antiferromagnetic coupling and is caused by RKKY interactions. The material constituting the third ferromagnetic layer is, for example, the same as that of the first ferromagnetic layer 1 . The magnetic coupling layer is Ru, Ir, or the like, for example.

The spacer layer 3 is a non-magnetic layer arranged between the first ferromagnetic layer 1 and the second ferromagnetic layer 2 . The spacer layer 3 is composed of a layer composed of a conductor, an insulator, or a semiconductor, or a layer including a current-carrying point composed of a conductor in an insulator. The thickness of the spacer layer 3 can be adjusted according to the orientation directions of the magnetization of the first ferromagnetic layer 1 and the magnetization of the second ferromagnetic layer 2 in the initial state, which will be described later.

For example, when the spacer layer 3 is made of an insulator, the magnetic element 10 has a magnetic tunnel junction (MTJ) made up of the first ferromagnetic layer 1, the spacer layer 3, and the second ferromagnetic layer 2. . Such an element is called an MTJ element. In this case, the magnetic element 10 can exhibit a tunnel magnetoresistance (TMR) effect. When the spacer layer 3 is made of metal, the magnetic element 10 can exhibit a giant magnetoresistive (GMR) effect. Such an element is called a GMR element. The magnetic element 10 may be called an MTJ element, a GMR element, or the like depending on the constituent material of the spacer layer 3, but is also generically called a magnetoresistance effect element.

When the spacer layer 3 is composed of an insulating material, materials containing aluminum oxide, magnesium oxide, titanium oxide, silicon oxide, or the like can be used. Further, these insulating materials may contain elements such as Al, B, Si and Mg, and magnetic elements such as Co, Fe and Ni. By adjusting the film thickness of the spacer layer 3 so that a high TMR effect is exhibited between the first ferromagnetic layer 1 and the second ferromagnetic layer 2, a high magnetoresistance ratio can be obtained. In order to efficiently use the TMR effect, the film thickness of the spacer layer 3 may be about 0.5 to 5.0 nm, or about 1.0 to 2.5 nm.

When the spacer layer 3 is made of a non-magnetic conductive material, a conductive material such as Cu, Ag, Au or Ru can be used. In order to efficiently utilize the GMR effect, the film thickness of the spacer layer 3 may be about 0.5 to 5.0 nm, or about 2.0 to 3.0 nm.

When the spacer layer 3 is made of a non-magnetic semiconductor material, materials such as zinc oxide, indium oxide, tin oxide, germanium oxide, gallium oxide, and ITO can be used. In this case, the film thickness of the spacer layer 3 may be about 1.0 to 4.0 nm.

When a layer containing current-carrying points composed of a conductor in a non-magnetic insulator is applied as the spacer layer 3, a non-magnetic conductor such as Cu, Au or Al is placed in the non-magnetic insulator composed of aluminum oxide or magnesium oxide. It is also possible to have a structure including a current-carrying point constituted by a conductor of Also, the conductor may be composed of a magnetic element such as Co, Fe, or Ni. In this case, the film thickness of the spacer layer 3 may be about 1.0 to 2.5 nm. The current-carrying point is, for example, a column having a diameter of 1 nm or more and 5 nm or less when viewed in a direction perpendicular to the film surface.

The magnetic element 10 may also have an underlying layer, a cap layer, a perpendicular magnetization inducing layer, and the like. The underlayer is between the second ferromagnetic layer 2 and the second electrode 30 . The underlayer is a seed layer or a buffer layer. The seed layer enhances the crystallinity of layers laminated on the seed layer. Seed layers are, for example, Pt, Ru, Hf, Zr, NiFeCr. The film thickness of the seed layer is, for example, 1 nm or more and 5 nm or less. A buffer layer is a layer that relaxes the lattice mismatch between different crystals. The buffer layer is, for example, Ta, Ti, W, Zr, Hf or nitrides of these elements. The film thickness of the buffer layer is, for example, 1 nm or more and 5 nm or less.

The cap layer is between the first ferromagnetic layer 1 and the first electrode 20 . The cap layer prevents damage to the underlying layer during processing and enhances the crystallinity of the underlying layer during annealing. The film thickness of the cap layer is, for example, 3 nm or less so that the first ferromagnetic layer 1 is sufficiently irradiated with light. The cap layer is, for example, MgO, W, Mo, Ru, Ta, Cu, Cr, or a laminated film of these.

The perpendicular magnetization inducing layer is formed when the first ferromagnetic layer 1 is a perpendicular magnetization film. A perpendicular magnetization inducing layer is laminated on the first ferromagnetic layer 1 . The perpendicular magnetization inducing layer induces perpendicular magnetic anisotropy of the first ferromagnetic layer 1 . The perpendicular magnetization inducing layer is, for example, magnesium oxide, W, Ta, Mo, or the like. When the perpendicular magnetization inducing layer is made of magnesium oxide, it is preferable that the magnesium oxide be oxygen-deficient in order to increase conductivity. The film thickness of the perpendicular magnetization inducing layer is, for example, 0.5 nm or more and 2.0 nm or less.

The photodetector 100 is manufactured by laminating each layer, annealing, and processing. First, the second electrode 30, the second ferromagnetic layer 2, the spacer layer 3, and the first ferromagnetic layer 1 are sequentially laminated on the substrate. Each layer is deposited by sputtering, for example.

The laminated film is then annealed. The annealing temperature is, for example, 250°C to 450°C. When the substrate is a circuit board, it is preferable to anneal it at 400° C. or higher. After that, the laminated film is processed into a predetermined columnar body by photolithography and etching. The columnar body may be a cylinder or a prism. For example, the shortest width of the columnar body when viewed in the z direction may be 10 nm or more and 2000 nm or less, or may be 30 nm or more and 500 nm or less.

Next, an insulating layer 50 is formed so as to cover the side surfaces of the columnar bodies. The insulating layer 50 may be laminated multiple times. Next, the upper surface of the first ferromagnetic layer 1 is exposed from the insulating layer 50 by chemical mechanical polishing (CMP), and the first electrode 20 is produced on the first ferromagnetic layer 1 .

The substrate and insulating layer 50 are then cut. Then, the cut surface is subjected to, for example, chemical mechanical polishing (CMP) and ion beam etching to remove the insulating layer 50, thereby removing the second electrode 30, the second ferromagnetic layer 2, the spacer layer 3, and the insulating layer 50 from the insulating layer 50. The first ferromagnetic layer 1 is exposed. As a result, the side surface 10s becomes a flat surface, and the side surface 30s, the side surface 10s, and the side surface 20s are continuous. Finally, the photodetector 100 is obtained by arranging the light irradiation section 40 at a position facing the side surface 10s.

Several examples of the operation of the photodetector 100 will now be described. The first ferromagnetic layer 1 is irradiated with light with varying light intensity. The output voltage from the photodetector 100 changes when the first ferromagnetic layer 1 is irradiated with light. In the first operation example, the case where the intensity of the light with which the first ferromagnetic layer 1 is irradiated has two levels of a first intensity and a second intensity will be described as an example. The intensity of the light of the second intensity is greater than the intensity of the light of the first intensity. The first intensity may be the case where the intensity of the light with which the first ferromagnetic layer 1 is irradiated is zero.

4 and 5 are diagrams for explaining a first operation example of the photodetector 100 according to the first embodiment. FIG. 4 is a diagram for explaining the first mechanism of the first operation example, and FIG. 5 is a diagram for explaining the second mechanism of the first operation example. In the upper graphs of FIGS. 4 and 5, the vertical axis represents the intensity of the light with which the first ferromagnetic layer 1 is irradiated, and the horizontal axis represents time. 4 and 5, the vertical axis is the resistance value of the magnetic element 10 in the z direction, and the horizontal axis is time.

First, in a state where the first ferromagnetic layer 1 is irradiated with light of a first intensity (hereinafter referred to as an initial state), the magnetization M1 of the first ferromagnetic layer 1 and the magnetization M2 of the second ferromagnetic layer 2 are parallel. , the resistance value in the z direction of the magnetic element 10 indicates a first resistance value R1, and the magnitude of the output voltage from the magnetic element 10 indicates a first value. The resistance value of the magnetic element 10 in the z-direction can be obtained by applying a voltage across both ends of the magnetic element 10 in the z-direction by flowing a sense current Is in the z-direction of the magnetic element 10, and using Ohm's law from the voltage value. Desired. An output voltage from the magnetic element 10 is generated between the first electrode 20 and the second electrode 30 . In the case of the example shown in FIG. 4, the sense current Is is caused to flow from the first ferromagnetic layer 1 toward the second ferromagnetic layer 2 . By passing the sense current Is in this direction, a spin transfer torque in the same direction as the magnetization M2 of the second ferromagnetic layer 2 acts on the magnetization M1 of the first ferromagnetic layer 1, and in the initial state, the magnetization M1 and magnetization M2 becomes parallel. Also, by passing the sense current Is in this direction, it is possible to prevent the magnetization M1 of the first ferromagnetic layer 1 from reversing during operation.

Next, the intensity of the light with which the first ferromagnetic layer 1 is irradiated changes from the first intensity to the second intensity. The second intensity is greater than the first intensity, and the magnetization M1 of the first ferromagnetic layer 1 changes from its initial state. The state of the magnetization M1 of the first ferromagnetic layer 1 when the first ferromagnetic layer 1 is not irradiated with light differs from the state of the magnetization M1 of the first ferromagnetic layer 1 at the second intensity. The state of the magnetization M1 is, for example, the tilt angle with respect to the z-direction, the magnitude, and the like.

For example, as shown in FIG. 4, when the intensity of light applied to the first ferromagnetic layer 1 changes from a first intensity to a second intensity, the magnetization M1 is tilted with respect to the z direction. Further, for example, as shown in FIG. 5, when the intensity of the light with which the first ferromagnetic layer 1 is irradiated changes from the first intensity to the second intensity, the magnitude of the magnetization M1 decreases. For example, when the magnetization M1 of the first ferromagnetic layer 1 is tilted with respect to the z-direction due to the light irradiation intensity, the tilt angle is greater than 0° and less than 90°.

When the magnetization M1 of the first ferromagnetic layer 1 changes from the initial state, the z-direction resistance of the magnetoresistive element 10 exhibits a second resistance R2, and the magnitude of the output voltage from the magnetic element 10 changes to a second value. indicate a value. The second resistance value R2 is greater than the first resistance value R1, and the second value of the output voltage is greater than the first value. The second resistance value R2 is between the resistance value (first resistance value R1) when the magnetizations M1 and M2 are parallel and the resistance value when the magnetizations M1 and M2 are antiparallel. .

In the case shown in FIG. 4, the spin transfer torque in the same direction as the magnetization M2 of the second ferromagnetic layer 2 acts on the magnetization M1 of the first ferromagnetic layer 1 . Therefore, the magnetization M1 tries to return to a state parallel to the magnetization M2, and when the intensity of the light applied to the first ferromagnetic layer 1 changes from the second intensity to the first intensity, the magnetic element 10 returns to its initial state. In the case shown in FIG. 5, when the intensity of the light applied to the first ferromagnetic layer 1 returns to the first intensity, the magnitude of the magnetization M1 of the first ferromagnetic layer 1 returns to its original value, and the magnetic element 10 returns to its initial state. return to state. In either case, the z-direction resistance of the magnetic element 10 returns to the first resistance R1. That is, when the intensity of the light with which the first ferromagnetic layer 1 is irradiated changes from the second intensity to the first intensity, the z-direction resistance of the photodetector 100 changes from the second resistance R2 to the first resistance Changing to value R1, the magnitude of the output voltage from magnetic element 10 changes from the second value to the first value.

The output voltage from the photodetector 100 changes in accordance with the change in the intensity of the light irradiated to the first ferromagnetic layer 1, and the change in the intensity of the irradiated light is the output voltage from the photodetector 100. It can be transformed into change. That is, the photodetector 100 can convert light into an electrical signal. For example, when the output voltage from the photodetector 100 is equal to or higher than the threshold, it is processed as a first signal (eg, "1"), and when it is less than the threshold, it is processed as a second signal (eg, "0").

Although the case where the magnetization M1 and the magnetization M2 are parallel in the initial state has been described as an example, the magnetization M1 and the magnetization M2 may be antiparallel in the initial state. In this case, the z-direction resistance of the magnetic element 10 decreases as the state of the magnetization M1 changes (for example, as the angle change from the initial state of the magnetization M1 increases). When the magnetization M1 and the magnetization M2 are antiparallel to each other as the initial state, it is preferable to flow the sense current Is from the second ferromagnetic layer 2 toward the first ferromagnetic layer 1 . By passing the sense current Is in this direction, a spin transfer torque in the opposite direction to the magnetization M2 of the second ferromagnetic layer 2 acts on the magnetization M1 of the first ferromagnetic layer 1, and in the initial state, the magnetization M1 and The magnetization M2 becomes antiparallel.

In the first operation example, the case where the light applied to the first ferromagnetic layer 1 has two levels of the first intensity and the second intensity was explained as an example. A case where the intensity of light irradiated to 1 is changed in multiple steps or in an analog manner will be described.

6 and 7 are diagrams for explaining a second operation example of the photodetector 100 according to the first embodiment. FIG. 6 is a diagram for explaining the first mechanism of the first operation example, and FIG. 7 is a diagram for explaining the second mechanism of the first operation example. In the upper graphs of FIGS. 6 and 7, the vertical axis is the intensity of the light with which the first ferromagnetic layer 1 is irradiated, and the horizontal axis is time. 6 and 7, the vertical axis represents the resistance value of the magnetic element 10 in the z direction, and the horizontal axis represents time.

In the case of FIG. 6, when the intensity of the light applied to the first ferromagnetic layer 1 increases, the magnetization M1 of the first ferromagnetic layer 1 is tilted from the initial state by energy from the outside due to the light irradiation. The angle between the direction of the magnetization M1 of the first ferromagnetic layer 1 when the first ferromagnetic layer 1 is not irradiated with light and the direction of the magnetization M1 when the first ferromagnetic layer 1 is irradiated with light is both greater than 0°. less than 90°.

When the magnetization M1 of the first ferromagnetic layer 1 tilts from the initial state, the resistance value of the magnetoresistive element 10 in the z direction changes. Then, the output voltage from the magnetic element 10 changes. For example, according to the gradient of the magnetization M1 of the first ferromagnetic layer 1, the z-direction resistance of the magnetic element 10 changes to a second resistance R2, a third resistance R3, and a fourth resistance R4. The output voltage from element 10 varies between a second value, a third value and a fourth value. The resistance values increase in order of the first resistance value R1, the second resistance value R2, the third resistance value R3, and the fourth resistance value R4. The output voltage from the magnetic element 10 increases in the order of the first value, second value, third value, and fourth value.

The magnetic element 10 changes the output voltage (resistance value of the magnetic element 10 in the z-direction) when the intensity of light applied to the first ferromagnetic layer 1 changes. For example, the first value (first resistance value R1) is "0", the second value (second resistance value R2) is "1", the third value (third resistance value R3) is "2", If the fourth value (fourth resistance value R4) is defined as "3", the photodetector 100 can output quaternary information. Although four values are read as an example here, the number of values to be read can be freely designed by setting the threshold value of the output voltage from the magnetic element 10 (resistance value of the magnetic element 10). Alternatively, the photodetector element 100 may output an analog value as it is.

Similarly, in the case of FIG. 7, when the intensity of the light irradiated to the first ferromagnetic layer 1 increases, the magnitude of the magnetization M1 of the first ferromagnetic layer 1 changes to the initial state due to the energy from the outside due to the light irradiation. becomes smaller from When the magnetization M1 of the first ferromagnetic layer 1 decreases from the initial state, the resistance value of the magnetoresistive element 10 in the z direction changes. Then, the output voltage from the magnetic element 10 changes. For example, depending on the magnitude of the magnetization M1 of the first ferromagnetic layer 1, the z-direction resistance value of the magnetic element 10 changes to a second resistance value R2, a third resistance value R3, and a fourth resistance value R4, The output voltage from the magnetic element 10 changes between a second value, a third value and a fourth value. Therefore, as in the case of FIG. 6, the photodetector element 100 can output the difference in these output voltages (resistance values) as multivalued or analog data.

Also in the case of the second operation example, similarly to the first operation example, when the intensity of the light with which the first ferromagnetic layer 1 is irradiated returns to the first intensity, the magnetization M1 of the first ferromagnetic layer 1 changes to The state is restored and the magnetic element 10 returns to its initial state.

Although the case where the magnetization M1 and the magnetization M2 are parallel in the initial state has been described as an example, the magnetization M1 and the magnetization M2 may be antiparallel in the initial state also in the second operation example.

Further, in the first operation example and the second operation example, the magnetization M1 and the magnetization M2 are parallel or antiparallel in the initial state, but the magnetization M1 and the magnetization M2 may be orthogonal in the initial state. For example, when the first ferromagnetic layer 1 is an in-plane magnetization film in which the magnetization M1 is oriented in one of the xy planes, and the second ferromagnetic layer 2 is a perpendicular magnetization film in which the magnetization M2 is oriented in the z direction, This case applies. Due to the magnetic anisotropy, the magnetization M1 is oriented in one of the xy planes and the magnetization M2 is oriented in the z direction, so that the magnetization M1 and the magnetization M2 are orthogonal to each other in the initial state.

8 and 9 are diagrams for explaining another example of the second operation example of the photodetector 100 according to the first embodiment. 8 and 9 differ in the flow direction of the sense current Is applied to the magnetic element 10. FIG. 8, the sense current Is is passed from the first ferromagnetic layer 1 to the second ferromagnetic layer 2. FIG. 9 shows the sense current Is flowing from the second ferromagnetic layer 2 to the first ferromagnetic layer 1. FIG.

8 and 9, the flow of the sense current Is in the magnetic element 10 causes a spin transfer torque to act on the magnetization M1 in the initial state. In the case of FIG. 8, the spin transfer torque acts so that the magnetization M1 is parallel to the magnetization M2 of the second ferromagnetic layer 2. In FIG. In the case of FIG. 9, the spin transfer torque acts so that the magnetization M1 of the second ferromagnetic layer 2 is antiparallel to the magnetization M2. In both cases of FIGS. 8 and 9, in the initial state, the effect of the magnetic anisotropy on the magnetization M1 is greater than the effect of the spin transfer torque, so the magnetization M1 is oriented in any direction within the xy plane. .

When the intensity of the light applied to the first ferromagnetic layer 1 increases, the magnetization M1 of the first ferromagnetic layer 1 tilts from the initial state due to the energy from outside due to the light irradiation. This is because the sum of the effect of the light irradiation applied to the magnetization M1 and the effect of the spin transfer torque is greater than the effect of the magnetic anisotropy on the magnetization M1. When the intensity of light irradiated to the first ferromagnetic layer 1 increases, the magnetization M1 in the case of FIG. It tilts so as to be antiparallel to the magnetization M2 of the second ferromagnetic layer 2 . Since the direction of the spin transfer torque acting on the magnetization M1 is different, the direction of inclination of the magnetization M1 in FIGS. 8 and 9 is different.

When the intensity of the light applied to the first ferromagnetic layer 1 increases, the resistance value of the magnetic element 10 decreases in the case of FIG. 8, and the output voltage from the magnetic element 10 decreases. In the case of FIG. 9, the resistance value of the magnetic element 10 increases and the output voltage from the magnetic element 10 increases.

When the intensity of the light applied to the first ferromagnetic layer 1 returns to the first intensity, the state of the magnetization M1 of the first ferromagnetic layer 1 returns to its original state due to the action of the magnetic anisotropy on the magnetization M1. As a result, the magnetic element 10 returns to its initial state.

Here, the first ferromagnetic layer 1 is an in-plane magnetization film and the second ferromagnetic layer 2 is a perpendicular magnetization film, but the relationship may be reversed. That is, in the initial state, the magnetization M1 may be oriented in the z direction, and the magnetization M2 may be oriented in any direction within the xy plane.

As described above, the photodetector element 100 according to the first embodiment can replace the light irradiated to the magnetic element 10 with the output voltage from the magnetic element 10, thereby replacing the light with an electric signal.

Further, the magnetic element 10 is irradiated with the light L from the side surface 10s. That is, the light L is likely to irradiate the portion of the first ferromagnetic layer 1 on the side of the spacer layer 3 as well. A change in the state of magnetization of the spacer layer 3 side portion of the first ferromagnetic layer 1 greatly contributes to a change in the output voltage from the magnetic element 10 (a change in the resistance value of the magnetic element 10 in the z direction). As a result, the responsiveness of the output voltage change from the magnetic element 10 (the resistance value change of the magnetic element 10) to the change in the state of the light L is high.

As described above, the first embodiment has been described in detail with reference to the drawings, but the first embodiment is not limited to this example.

For example, like the photodetector element 101 shown in FIG. 10, the side surface 11s of the magnetic element 11 may be inclined with respect to the z direction. The side surface 11 s is continuous with the side surface 21 s of the first electrode 21 and the side surface 31 s of the second electrode 31 . 11 s of side surfaces are flat surfaces. In the photodetector 101 according to the first modification, the portion of the first ferromagnetic layer 1 on the spacer layer side is also easily irradiated with light, so that the same effects as those of the photodetector 100 can be obtained.

11 and 12, the shape of the magnetic elements 12 and 13 when viewed in the z direction may be other than rectangular.

The magnetic element 12 shown in FIG. 11 has a circular shape when viewed in the z direction. A portion of the side surface 12s of the magnetic element 12, the side surface 20s of the first electrode 20, and the side surface 30s of the second electrode 30 are in contact with the same virtual plane VS. The side surface 12s is in contact with the virtual plane VS at a linear portion extending in the z direction. The portion of the side surface 12s in contact with the virtual plane VS is continuous with the side surface 20s and the side surface 30s.

The magnetic element 13 shown in FIG. 12 has a shape of a partially cut circle when viewed from the z direction. The side surface of the magnetic element 13 is composed of a flat side surface 13s and an arc-shaped side surface when viewed from the z direction. The side surface 13s, the side surface 20s, and the side surface 30s are in contact with the same virtual plane VS. The side 13s, the side 20s, and the side 30s are continuous.

Also, like the photodetector 104 shown in FIG. 13, the shape of the first electrode 22 and the second electrode 32 when viewed in the z direction may be other than rectangular.

The magnetic element 12 shown in FIG. 13 has a circular shape when viewed in the z direction. Also, the first electrode 22 and the second electrode 32 shown in FIG. 13 have an elliptical shape when viewed in the z direction. A portion of the side surface 12s of the magnetic element 12, a portion of the side surface 22s of the first electrode 22, and a portion of the side surface 32s of the second electrode 32 are in contact with the same virtual plane VS. The side surface 12s is in contact with the virtual plane VS at a linear portion extending in the z direction. The side surface 22s is in contact with the virtual plane VS at a linear portion extending in the z direction. The side surface 32s is in contact with the virtual plane VS at a linear portion extending in the z direction. The portion of the side surface 12s in contact with the virtual plane VS and the portions of the side surfaces 22s and 32s in contact with the virtual plane VS are continuous.

Also, the example in which part of the side surfaces of both the first electrode and the second electrode and part of the side surface of the magnetic element are in contact with the same imaginary plane VS has been illustrated and described so far, but this is the only case. can't For example, only part of the side surface of one of the first electrode and the second electrode and part of the side surface of the magnetic element may be in contact with the same virtual plane VS.

"Second Embodiment"
FIG. 14 is a yz sectional view of the photodetector 105 according to the second embodiment. The photodetector 105 differs from the photodetector 100 according to the first embodiment in that it has an oxide film 60 . In the second embodiment, the same reference numerals are given to the same configurations as in the first embodiment, and the description thereof is omitted.

The oxide film 60 covers the flat surfaces consisting of the side surface 10s, the side surface 20s and the side surface 30s. FIG. 14 shows an example in which the oxide film 60 covers the entire flat surface consisting of the side surfaces 10s, 20s and 30s, but it may be configured to cover only a portion of the flat surface. For example, the oxide film 60 may be configured to cover only the side surfaces 10s of the magnetic element 10 .

The oxide film 60 is transparent to the wavelength range of light with which the magnetic element 10 is irradiated. The oxide film 60 is, for example, an insulating oxide. The oxide film 60 is, for example, silicon oxide, aluminum oxide, or the like. The oxide film 60 protects the side surface 10s of the magnetic element 10 from corrosion, wear, and the like.

The photodetector 105 according to the second embodiment has the same effects as the photodetector 100 . In addition, by including the oxide film 60, the photodetector 105 has excellent weather resistance.

"Third Embodiment"
FIG. 15 is a yz sectional view of the photodetector 106 according to the third embodiment. The photodetecting element 106 differs from the photodetecting element 100 according to the first embodiment in that it has a heating portion 70 . In the third embodiment, the same reference numerals are given to the same configurations as in the first embodiment, and the description thereof is omitted.

The heat generating portion 70 is located at a position where it can heat the first ferromagnetic layer 1 . The heat-generating part 70 is behind the magnetic element 10 in the light irradiation direction with respect to the magnetic element 10, for example. The heat generating portion 70 does not have to overlap the magnetic element 10 when viewed from the light irradiation direction. The heat-generating part 70 is located on the side opposite to the surface of the magnetic element 10 that is mainly irradiated with the light L, with the magnetic element 10 interposed therebetween.

The exothermic part 70 is, for example, a coil. The heat generating portion 70 is a resistor made of, for example, Cu, a nickel-chromium alloy, an iron-chromium-aluminum alloy, or the like. The heat-generating portion 70 generates heat due to the current flowing through the resistor.

When the heating portion 70 generates heat, the first ferromagnetic layer 1 is heated. The heated first ferromagnetic layer 1 expands. When the first ferromagnetic layer 1 expands, the side surface of the first ferromagnetic layer 1 protrudes from the virtual plane connecting the side surface 20s and the side surface 30s.

The photodetector 106 according to the third embodiment has the same effects as the photodetector 100 . In addition, the side surface of the first ferromagnetic layer 1 can be protruded from the virtual plane connecting the side surface 20s and the side surface 30s by the heat generation of the heat generating portion 70, and the distance between the side surface of the first ferromagnetic layer 1 and the light irradiation portion 40 can be increased. can change. As a result, the intensity of the light applied to the first ferromagnetic layer 1 can be adjusted without changing the irradiation intensity from the light irradiation unit 40 .

"Fourth Embodiment"
FIG. 16 is a yz sectional view of the photodetector 107 according to the fourth embodiment. The photodetector 107 differs from the photodetector 100 according to the first embodiment in that it has a heating portion 70 and an expansion portion 80 . In the third embodiment, the same reference numerals are given to the same configurations as in the first embodiment, and the description thereof is omitted.

The heat generating portion 70 is located at a position where it can heat the expansion portion 80 . The heat-generating part 70 is behind the magnetic element 10 in the light irradiation direction with respect to the magnetic element 10, for example. The heat generating portion 70 does not have to overlap the magnetic element 10 when viewed from the light irradiation direction. The heat-generating part 70 is located on the side opposite to the surface of the magnetic element 10 that is mainly irradiated with the light L, with the magnetic element 10 interposed therebetween.

The expanding portion 80 is behind the magnetic element 10 in the light irradiation direction with respect to the magnetic element 10, for example. The expanded portion 80 does not have to overlap the magnetic element 10 when viewed from the light irradiation direction. The expanded portion 80 is located on the side opposite to the surface of the magnetic element 10 that is mainly irradiated with the light L, with the magnetic element 10 interposed therebetween. The expansion portion 80 is heated and expands when the heat generating portion 70 generates heat. The expanded portion 80 is located at a position where the first ferromagnetic layer 1 can be pushed out.

The expansion part 80 is made of a material having a larger coefficient of linear thermal expansion than the first ferromagnetic layer 1 . The expansion part 80 is, for example, aluminum, magnesium, zinc, tin, or an alloy containing these.

When the heating portion 70 generates heat, the expansion portion 80 is heated. When the heated expansion part 80 expands, the first ferromagnetic layer 1 is pushed outward. As a result, the side surface of the first ferromagnetic layer 1 protrudes from the virtual plane connecting the side surface 20s and the side surface 30s.

The photodetector 107 according to the fourth embodiment has the same effects as the photodetector 100 . Further, the distance between the side surface of the first ferromagnetic layer 1 and the light irradiation section 40 can be changed by the heat generation of the heat generating section 70 and the expansion of the expansion section 80 . As a result, the intensity of the light applied to the first ferromagnetic layer 1 can be adjusted without changing the irradiation intensity from the light irradiation unit 40 .

As described above, the present invention is not limited to the above-described embodiments and modifications, and various modifications and changes are possible within the scope of the present invention described in the claims. For example, the characteristic configurations of the above embodiments and modified examples may be combined.

The photodetector elements according to the above embodiments and modifications can be applied to photo sensor devices such as image sensors, transmission/reception devices of communication systems, and the like.

FIG. 17 is a block diagram of a transmitting/receiving device 1000 according to the first application example. The transmitting/receiving device 1000 includes a receiving device 300 and a transmitting device 400 . The receiver 300 receives the optical signal L1, and the transmitter 400 transmits the optical signal L2.

The receiver 300 includes, for example, a photodetector 301 and a signal processor 302 . The photo-sensing element 301 is any of the photo-sensing elements 100-107 of the embodiments or variations described above. In the receiving device 300, the first ferromagnetic layer 1 is irradiated with light containing a high-frequency optical signal L1 and varying in intensity. A lens may be arranged on the side of the first ferromagnetic layer 1 in the stacking direction of the photodetecting element 301 so that the first ferromagnetic layer 1 is irradiated with light condensed through the lens. The lens may be formed during the wafer process for forming the photodetector 301 . Also, the light passing through the waveguide may be irradiated onto the first ferromagnetic layer 1 of the photodetector 301 . The light with which the first ferromagnetic layer 1 of the photodetector 301 is irradiated is, for example, laser light. The photo-sensing element 301 converts the optical signal L1 into an electrical signal. The operation of the photodetector 301 may be either the first operation example or the second operation example. A signal processing unit 302 processes the electrical signal converted by the photodetector 301 . The signal processing unit 302 receives the signal included in the optical signal L1 by processing the electrical signal generated from the photodetector 301 . The receiver 300 receives signals included in the optical signal L1 based on the output voltages from the magnetic elements 10-13.

The transmitter 400 includes, for example, a light source 401 , an electrical signal generation element 402 and an optical modulation element 403 . Light source 401 is, for example, a laser element. Light source 401 may be external to transmitter 400 . The electrical signal generation element 402 generates an electrical signal based on the transmitted information. The electrical signal generation element 402 may be integrated with the signal conversion element of the signal processing section 302 . The optical modulation element 403 modulates the light output from the light source 401 based on the electrical signal generated by the electrical signal generation element 402, and outputs an optical signal L2.

FIG. 18 is a conceptual diagram of an example of a communication system. The communication system shown in FIG. 18 has two terminal devices 500 . The terminal device 500 is, for example, a smartphone, tablet, personal computer, or the like.

Each terminal device 500 includes a receiving device 300 and a transmitting device 400 . An optical signal transmitted from the transmitting device 400 of one terminal device 500 is received by the receiving device 300 of the other terminal device 500 . Light used for transmission and reception between the terminal devices 500 is, for example, visible light. The receiving device 300 has the photodetecting elements 100 to 107 described above as a photodetecting element 301 . Since the photodetecting elements 100 to 107 described above have good responsiveness to light, the communication system shown in FIG. 18 has high reliability.

FIG. 19 is a schematic cross-sectional view of an optical sensor device 2000 according to a second application example. The photosensor device 2000 has a circuit board 110, a wiring layer 120, and a plurality of photosensors S, for example. Each of the wiring layer 120 and the plurality of photosensors S is formed on the circuit board 110 .

Each of the plurality of photosensors S has a photodetector element 100, a wavelength filter F, and a lens R, for example. Although FIG. 19 shows an example using the photodetector 100, photodetectors 101 to 107 may be used instead of the photodetector 100. FIG. The light that has passed through the wavelength filter F is irradiated onto the photodetector element 100 . As described above, the photodetector element 100 converts the light applied to the magnetic element 10 into an electrical signal. The photodetector 100 preferably operates in the second operation example.

The wavelength filter F selects light of a specific wavelength and transmits light of a specific wavelength range. The wavelength range of light transmitted by each wavelength filter F may be the same or different. For example, the optical sensor device 2000 includes an optical sensor S (hereinafter referred to as a blue sensor) having a wavelength filter F that transmits blue (wavelength range of 380 nm or more and less than 490 nm) and green (wavelength range of 490 nm or more and less than 590 nm). and an optical sensor S (hereinafter referred to as a green sensor) having a wavelength filter F that transmits red (a wavelength range of 590 nm or more and less than 800 nm) (hereinafter referred to as a red sensor ) and may have By arranging a blue sensor, a green sensor, and a red sensor as one pixel and arranging the pixels, the optical sensor device 2000 can be used as an image sensor.

Lens R converges light toward magnetic element 10 . In the photosensor S shown in FIG. 19, one photodetector element 100 is arranged below one wavelength filter F, but a plurality of photodetector elements 100 may be arranged below one wavelength filter F. .

The circuit board 110 has, for example, an analog-to-digital converter 111 and an output terminal 112 . The electrical signal sent from the optical sensor S is converted into digital data by the analog-to-digital converter 111 and output from the output terminal 112 .

The wiring layer 120 has a plurality of wirings 121 . An interlayer insulating film 122 is provided between the plurality of wirings 121 . The wiring 121 electrically connects between each of the optical sensors S and the circuit board 110 and between each arithmetic circuit formed on the circuit board 110 . Each of the photosensors S and the circuit board 110 are connected, for example, via a through-wiring penetrating the interlayer insulating film 122 in the z-direction. Noise can be reduced by shortening the inter-wiring distance between each of the optical sensors S and the circuit board 110 .

The wiring 121 has conductivity. The wiring 121 is, for example, Al, Cu, or the like. The interlayer insulating film 122 is an insulator that insulates between wirings of a multilayer wiring and between elements. The interlayer insulating film 122 is, for example, an oxide, nitride, or oxynitride of Si, Al, or Mg. The interlayer insulating film 122 is, for example, silicon oxide (SiO _x ), silicon nitride (SiN _x ), silicon carbide (SiC), chromium nitride, silicon carbonitride (SiCN), silicon oxynitride (SiON), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO _x ), and the like.

The optical sensor device 2000 described above can be used, for example, in a terminal device. FIG. 20 is a schematic diagram of an example of the terminal device 600. As shown in FIG. The left side of FIG. 20 is the front side of the terminal device 600 and the right side of FIG. 20 is the back side of the terminal device 600 . The terminal device 600 has a camera CA. The optical sensor device 2000 described above can be used as the imaging element of this camera CA. In FIG. 20, a smart phone is illustrated as an example of the terminal device 600, but it is not limited to this case. The terminal device 600 is, for example, a tablet, a personal computer, a digital camera, etc., other than a smartphone.

REFERENCE SIGNS LIST 1 first ferromagnetic layer 2 second ferromagnetic layer 3 spacer layer 10, 11, 12, 13 magnetic element 20, 21, 22 first electrode 30, 31, 32 second Electrode 10s, 11s, 12s, 13s, 20s, 21s, 22s, 30s, 31s, 32s... Side surface 40... Light irradiation part 50... Insulating layer 60... Oxide film 70... Heat generating part 80... Expansion part DESCRIPTION OF SYMBOLS 100,101,102,103,104,105,106,107... Photodetection element, 110... Circuit board, 111... Analog-to-digital converter, 112... Output terminal, 120... Wiring layer, 121... Wiring, 122... Interlayer insulation Membrane 300 Receiver 301 Photodetector 302 Signal processor 400 Transmitter 401 Light source 402 Electrical signal generator 403 Optical modulator 500, 600 Terminal device 1000 Transmitter/receiver 2000 Optical sensor device CA Camera F Wavelength filter R Lens S Optical sensor

Claims (11)

a magnetic element comprising a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer;
The photodetector, wherein the first ferromagnetic layer is irradiated with light from a direction crossing the stacking direction of the magnetic element. further comprising a first electrode and a second electrode sandwiching the magnetic element in the stacking direction;
At least one side surface of the first electrode and the second electrode and the side surface of the magnetic element are at least partially in contact with the same virtual plane,
2. The photodetector according to claim 1, wherein said first ferromagnetic layer is irradiated with said light from said virtual plane side. A part of the side surface of the magnetic element is a flat surface,
3. The photodetector according to claim 1, wherein said flat surface is irradiated with said light. A part of the side surface of the magnetic element is a flat surface,
3. The photo-sensing element according to claim 2, wherein said flat surface is in contact with said imaginary plane. 5. The photodetector according to claim 3, further comprising an oxide film covering said flat surface and capable of transmitting said light. further having a heat generating part,
6. The photodetector element according to claim 1, wherein said heat generating portion is located behind said magnetic element in a light irradiation direction in which said light is mainly applied to said magnetic element. further having an expansion part;
The heat generating portion is located at a position capable of heating the expansion portion,
the expanding portion is located behind the magnetic element in a light irradiation direction in which the light is mainly irradiated to the magnetic element;
7. The photodetector according to claim 6, wherein said expansion portion has a linear thermal expansion coefficient larger than that of said first ferromagnetic layer. 8. The photodetector element according to claim 1, wherein the light includes a high-frequency optical signal and changes in intensity. 8. The photodetector element according to claim 1, wherein the light is light transmitted through a wavelength filter. A receiver comprising the photodetector element according to any one of claims 1 to 8. A photosensor device comprising the photosensing element according to any one of claims 1 to 7 and 9.

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