WO2024038686A1

WO2024038686A1 - Light-emitting device

Info

Publication number: WO2024038686A1
Application number: PCT/JP2023/023902
Authority: WO
Inventors: 利昭長谷川; 利仁三浦; 博之柏原
Original assignee: ソニーセミコンダクタソリューションズ株式会社
Priority date: 2022-08-19
Filing date: 2023-06-28
Publication date: 2024-02-22

Abstract

This light-emitting device comprises: a first compound semiconductor layer that is of a first conductivity type; an active layer that is laminated on the first compound semiconductor layer; a second compound semiconductor layer that is of a second conductivity type opposite to the first conductivity type, and that is laminated to the active layer on the opposite side from the first compound semiconductor layer; a first reflective layer that is provided separately from the surface of the second compound semiconductor layer on the opposite side from the active layer, and that reflects light emitted from the active layer; and a first electrode that is provided between the second compound semiconductor layer and the first reflective layer and that electrically connects respective parts of the second compound semiconductor layer and the first reflective layer.

Description

light emitting device

The present disclosure relates to a support that supports a display unit, and a display device including the display unit and the support.

Patent Document 1 discloses a micro light emitting device. In this micro light emitting device, a compound semiconductor is laminated on a drive circuit board. The compound semiconductor is formed by sequentially stacking a p-side layer, a light-emitting layer, and an n-side layer from the drive circuit board side. A p-electrode is electrically connected to the p-side layer, and an n-electrode is electrically connected to the n-side layer.
The micro light emitting device configured in this manner emits light emitted from the light emitting layer from the n-side layer side, thereby constructing an image display device.

JP2019-204823A

In the above micro light emitting device, a transparent electrode is formed over the entire surface of the p-side layer of the compound semiconductor facing the drive circuit board, and the p-side layer and the p-electrode are electrically connected through this transparent electrode. There is. The p-electrode is formed over most of the entire surface of the p-side layer.

By the way, in the above-mentioned micro light emitting device, no consideration is given to leakage of light emitted from the light emitting layer to the drive circuit board side. Therefore, with the progress of further miniaturization of light emitting devices, it is desired to improve the light extraction efficiency and realize high image quality as image display devices.

A light emitting device according to a first embodiment of the present disclosure includes a first compound semiconductor layer of a first conductivity type, an active layer stacked on the first compound semiconductor layer, and a side of the active layer opposite to the first compound semiconductor layer. a second compound semiconductor layer of a second conductivity type opposite to the first conductivity type; a first reflective layer that reflects the light that is reflected, and is disposed between the second compound semiconductor layer and the first reflective layer, and electrically connects a portion of each of the second compound semiconductor layer and the first reflective layer. A first electrode.

A light emitting device according to a second embodiment of the present disclosure is the light emitting device according to the first embodiment, which is disposed between the second compound semiconductor layer and the first reflective layer, has light transmittance, and The device further includes an insulator having insulation properties.

In the light emitting device according to the third embodiment of the present disclosure, in the light emitting device according to the first embodiment or the second embodiment, at least a portion of the first compound semiconductor layer, the active layer, and the second compound semiconductor layer have a mesa shape. has. This light emitting device further includes a second reflective layer that is disposed along the side surface of the mesa shape and reflects light emitted from the active layer and light reflected from the first reflective layer toward the first compound semiconductor layer. There is.

A light emitting device according to a fourth embodiment of the present disclosure is a light emitting device according to any one of the first to third embodiments, in which a barrier layer is provided on the opposite side of the first reflective layer from the second compound semiconductor layer. The device further includes a second electrode in which a metal layer, an Al alloy layer, and a barrier metal layer are each sequentially laminated.

FIG. 1 is a schematic cross-sectional view of a light emitting device according to a first embodiment of the present disclosure. FIG. 2 is an enlarged plan view of main parts of the light emitting device shown in FIG. 1. FIG. 3 is an enlarged sectional view of a light emitting element that constructs the light emitting device shown in FIGS. 1 and 2. FIG. FIG. 4 is a bottom view of essential parts showing the configuration of the first reflective layer and the first electrode of the light emitting element shown in FIG. 3. FIG. FIG. 5 is a first step cross-sectional view corresponding to FIG. 3 illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 6 is a sectional view of the second step. FIG. 7 is a sectional view of the third step. FIG. 8 is a sectional view of the fourth step. FIG. 9 is a sectional view of the fifth step. FIG. 10 is a sectional view of the sixth step. FIG. 11 is a sectional view of the seventh step. FIG. 12 is a cross-sectional view of the eighth step. FIG. 13 is a bottom view of essential parts showing the configuration of a first reflective layer and a first electrode of a light emitting element that constructs a light emitting device according to a second embodiment of the present disclosure. FIG. 14 is a bottom view of essential parts showing the configuration of a first reflective layer and a first electrode of a light emitting element that constructs a light emitting device according to a first modification of the second embodiment. FIG. 15 is a bottom view of essential parts showing the configuration of a first reflective layer and a first electrode of a light emitting element that constructs a light emitting device according to a second modification of the second embodiment. FIG. 16 is an enlarged sectional view corresponding to FIG. 3 of a light emitting element that constructs a light emitting device according to a third embodiment of the present disclosure. FIG. 17 is a bottom view of essential parts corresponding to FIG. 4, showing the configuration of the first reflective layer and the first electrode of the light emitting element shown in FIG. 16. FIG. 18 is an enlarged sectional view corresponding to FIG. 3 of a light emitting element that constructs a light emitting device according to a fourth embodiment of the present disclosure. FIG. 19 is a bottom view of essential parts corresponding to FIG. 4, showing the configuration of the first reflective layer and the first electrode of the light emitting element shown in FIG. 18. FIG. 20 is an enlarged sectional view corresponding to FIG. 3 of a light emitting element that constructs a light emitting device according to a fifth embodiment of the present disclosure. FIG. 21 is a block diagram showing an example of a schematic configuration of a vehicle control system. FIG. 22 is an explanatory diagram showing an example of the installation positions of the outside-vehicle information detection section and the imaging section.

Embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the explanation will be given in the following order.
1. First Embodiment The first embodiment is a first example in which the present technology is applied to a light emitting device and a method for manufacturing the same.
2. Second Embodiment The second embodiment is a second example in which the structure of the light emitting element is changed in the light emitting device according to the first embodiment.
3. Third Embodiment The third embodiment is a third example in which the structure of the light emitting element is changed in the light emitting device according to the first embodiment or the second embodiment.
4. Fourth Embodiment The fourth embodiment is a fourth example in which the structure of the light emitting element is changed in the light emitting devices according to the first to third embodiments.
5. Fifth Embodiment The fifth embodiment is a fifth example in which the structure of the light emitting element is changed in the light emitting devices according to the first to fourth embodiments.
6. Application Example to a Mobile Object This application example describes an example in which the present technology is applied to a vehicle control system, which is an example of a mobile object control system.
7. Other embodiments

<1. First embodiment>
A light emitting device 1 and a method for manufacturing the same according to a first embodiment of the present disclosure will be described using FIGS. 1 to 12.
Here, in the figure, the arrow X direction shown as appropriate is one plane direction when the light emitting device 1 is placed on a plane for convenience. The arrow Y direction is another plane direction orthogonal to the arrow X direction. Further, the arrow Z direction is an upward direction orthogonal to the arrow X direction and the arrow Y direction. The arrow X direction, arrow Y direction, and arrow Z direction exactly correspond to the X-axis direction, Y-axis direction, and Z-axis direction of the three-dimensional coordinate system.
Note that these directions are shown to aid understanding of the present technology, and do not limit the direction of the present technology.

[Configuration of light emitting device 1]
(1) Overall schematic structure of the light emitting device 1 FIG. 1 shows an example of a schematic cross-sectional structure of the light emitting device 1 according to the first embodiment. FIG. 2 shows an example of a planar structure of the light emitting element 30 and color conversion layer 40 of the light emitting device 1.

As shown in FIG. 1, the light emitting device 1 according to the first embodiment includes a substrate region 2, a light emitter region 3, a color conversion region 4, and a filter region 5 in the longitudinal cross-sectional direction, which is the direction of arrow Z. and an optical system area 6. Further, the light emitting device 1 includes an element arrangement region 7 and a peripheral region 8 in the plane direction, which is the direction of the arrow X and the direction of the arrow Y.
The light emitting device 1 mainly includes a substrate 20 included in the substrate region 2 and a light emitting body 35 disposed in the light emitter region 3 and including a plurality of light emitting elements 30 arranged in the element arrangement region 7. It is provided as an element.

(2) Configuration of Substrate Region 2 The substrate region 2 includes a substrate 20 and a drive circuit 21 mounted on the main surface of the substrate 20. Here, the main surface of the substrate 20 is one main surface of the substrate 20 on which semiconductor elements (not shown) such as drive transistors are manufactured, and furthermore, the drive circuit 21 is constructed.

For example, a single crystal silicon (Si) substrate is used as the substrate 20. An insulator 201 is formed on the back and side surfaces of the substrate 20 opposite to the main surface. As the insulator 201, for example, a silicon nitride (SiN) film or a silicon oxide (SiO) film can be practically used.

(2-1) Configuration of the drive circuit 21 The drive circuit 21 is constructed from a semiconductor element (not shown) formed on the main surface of the substrate 20. The drive transistor as a semiconductor element includes, for example, a complementary insulated gate field effect transistor (IGFET). Insulated gate field effect transistors include at least both field effect transistors (MISFETs) with metal/insulator/semiconductor structures and field effect transistors (MOSFETs) with metal/oxide/semiconductor structures.

(2-2) Configuration of wiring layer 24 The drive circuit 21 is electrically connected to the first terminal 281 through the wiring layer 24. The wiring layer 24 here includes a plug wiring 240, a first layer wiring 241, a second layer wiring 242, a third layer wiring 243, a fourth layer wiring 244, and a plug wiring 245. We are prepared.

The plug wiring 240 is formed on, for example, a main electrode of an insulated gate field effect transistor (not shown), and is electrically connected to this main electrode. For example, dungsten (W) is used for the plug wiring 240.
The first layer wiring 241 is formed on the plug wiring 240 and is electrically connected to the plug wiring 240. The second layer wiring 242 is formed on the first layer wiring 241 and is electrically connected to the first layer wiring 241. The third layer wiring 243 is formed on the second layer wiring 242 and is electrically connected to the second layer wiring 242. The fourth layer wiring 244 is formed on the third layer wiring 243 and is electrically connected to the third layer wiring 243. Each of the first layer wiring 241 to the fourth layer wiring 244 is formed with aluminum (Al) as a main composition, for example.
The plug wiring 245 is formed in the fourth layer wiring 244 and is electrically connected to the fourth layer wiring 244 . The plug wiring 245 is made of the same material as the plug wiring 240, for example.

Further, an insulator 29 is provided in the wiring layer 24. The insulator 29 is formed around the plug wiring 240 and the plug wiring 245. Further, the insulator 29 is provided between the first layer wiring 241 and the second layer wiring 242, between the second layer wiring 242 and the third layer wiring 243, and between the third layer wiring 243 and the fourth layer wiring 243. It is formed between the layer wiring 244 and the like. The insulator 29 is formed of, for example, a SiO film or a SiN film.

(2-3) Structure of the light-shielding film 26 and the light-absorbing film 27 In the wiring layer 24, the first terminal 281 is electrically connected to the plug wiring 245 through the light-absorbing film 27 and the light-shielding film 26, respectively. There is.

The light shielding film 26 is disposed closer to the drive circuit 21 than the light absorption film 27 is. Here, the light shielding film 26 is configured to cover, for example, a drive transistor of the drive circuit 21. In other words, the light shielding film 26 is formed as an electrical path that electrically connects the drive circuit 21 and the first terminal 281, and is configured to block light leaking toward the drive circuit 21 side emitted from the light emitting element 30. There is.
The light shielding film 26 is formed of a single layer of metal whose main composition is, for example, Al, copper (Cu), W, or titanium (Ti).

The light absorption film 27 is disposed on the light-emitting element 30 side of the light-shielding film 26. The light absorption film 27 is formed to have the same planar shape as the light shielding film 26 when viewed from the direction of arrow Z (hereinafter simply referred to as "planar view"). The light absorption film 27 is formed as an electrical path that absorbs light leaking toward the drive circuit 21 side emitted from the light emitting element 30 and further electrically connects the drive circuit 21 and the first terminal 281.
The light absorption film 27 is made of, for example, a metal or metal compound whose main composition is titanium nitride (TiN), cobalt (Co), nitrogen-doped titanium oxide (TiON), tantalum nitride (TaN), or amorphous carbon (a-C). It is formed from a single layer film.

(2-4) Configuration of the first terminal 281 The first terminal 281 is electrically connected to the light absorption film 27 and disposed on the insulator 29. The first terminal 281 is configured to be electrically connected to one of the light emitting elements 30 (specifically, the second compound semiconductor layer 32). The first terminal 281 is made of, for example, Cu, which has a low resistance value.

On the other hand, in the peripheral region 8 , a second terminal 282 is provided on the insulator 29 . The second terminal 282 is configured to be electrically connected to the other side of the light emitting element 30 (specifically, the first compound semiconductor layer 31) or to the outside of the light emitting device 1.
Here, the second terminal 282 is formed on the same conductive layer as the light shielding film 26 and the light absorption film 27, and is formed of the same conductive material.

(3) Structure of the light emitter region 3 As shown in FIGS. 1 and 2, the light emitter region 3 is on the substrate region 2 and includes a light emitter 35 disposed on the insulator 29. . Here, the light emitting body 35 is configured by arranging a plurality of light emitting elements 30 formed from a compound semiconductor layer in a matrix along the direction of the light emitting surface of the light emitting element 30 (arrow X direction and arrow Y direction). There is.
explain in detail. Here, as shown in FIG. 2, the light emitting element 30 is formed in a hexagonal shape when viewed from above. The light emitting elements 30 are arranged in the direction of the arrow X and in a direction inclined by 30 degrees toward the direction of the arrow X with respect to the direction of the arrow Y (direction of the arrow Y). The light emitting element 30 includes a light emitting element 30 (R) that emits red light, which is the three primary colors of light, a light emitting element 30 (B) that emits blue light, and a light emitting element 30 (G) that emits green light.
The light emitting elements 30(R), 30(B), and 30(G) are arranged with their centers exactly aligned with the vertices of an equilateral triangle. That is, in the first embodiment, each of the light emitting elements 30 (R), the light emitting elements 30 (B), and the light emitting elements 30 (G) are arranged in a delta arrangement.

The light emitter 35 further includes an insulator 34 formed around the plurality of light emitting elements 30 except for the light emitting surface. The insulator 34 is formed mainly of a SiO film or a SiN film.

(3-1) Configuration of Light-Emitting Element 30 FIG. 3 shows an example of an enlarged cross-sectional configuration of the light-emitting element 30 that constructs the light-emitting device 1. FIG. 4 shows an example of the configuration of the first reflective layer 361 and the first electrode 363 of the light emitting element 30. FIG. 4 is a bottom view taken along the line AA shown in FIG. 3 and viewed from the direction opposite to the direction of arrow Z.
Note that the bottom view corresponding to FIG. 4 used in the second embodiment and later described below is a bottom view cut at the same position.

As shown in FIGS. 1 and 3, the light emitting element 30 is configured as a light emitting diode (LED) including a first compound semiconductor layer 31, a second compound semiconductor layer 32, and an active layer 33. In addition, in each of FIG. 1 and FIG. 3, the direction of the arrow Z direction of the light emitting element 30 is opposite.
The light emitting element 30 is formed mainly of a III-V compound semiconductor, for example. The first compound semiconductor layer 31 is disposed on the color conversion region 4 side and on the light emission side. The first compound semiconductor layer 31 is made of, for example, n-type gallium nitride (n-GaN). Here, the "n type" is the "first conductivity type" according to the present technology.
The second compound semiconductor layer 32 is provided on the substrate region 2 side. The second compound semiconductor layer 32 is made of, for example, p-type gallium nitride (p-GaN). Here, "p type" is a "second conductivity type" opposite to the first conductivity type according to the present technology.
The active layer 33 is disposed between the first compound semiconductor layer 31 and the second compound semiconductor layer 32. In other words, the active layer 33 is stacked on the first compound semiconductor layer 31, and the second compound semiconductor layer 32 is stacked on the side of the active layer 33 opposite to the first compound semiconductor layer 31. The active layer 33 is formed as a light emitting layer that emits light. Although not limited to this, in the first embodiment, the light emitting element 30 emits blue light.

In one light emitting element 30, at least a portion of the first compound semiconductor layer 31, the active layer 33, and the second compound semiconductor layer 32 have a mesa-shaped cross section. That is, as described above, the light emitting element 30 is formed in a hexagonal shape when viewed from above, and is formed into a mesa shape when viewed in the direction of arrow Y (hereinafter simply referred to as "in side view").
Note that the planar shape of the light emitting element 30 is not limited to a hexagonal shape. The planar shape of the light emitting element 30 may be, for example, circular, rectangular, or the like.

(3-2) Configuration of Transparent Electrode 321 In the light emitting element 30, the transparent electrode 321 is provided on the surface of the second compound semiconductor layer 32 on the substrate region 2 side. The transparent electrode 321 is electrically connected to substantially the entire surface of the second compound semiconductor layer 32 . The transparent electrode 321 is formed for each light emitting element 30, and is formed to have the same planar shape as the second compound semiconductor layer 32 in plan view. The transparent electrode 321 is made of, for example, indium tin oxide (ITO). Thereby, the transparent electrode 321 is connected to the second compound semiconductor layer 32 through ohmic contact.

(3-3) Configuration of first reflective layer 361 As shown in FIGS. 1 to 4, each of the plurality of light emitting elements 30 includes a first reflective layer 361, a first electrode 363, an insulator 364, a second reflective A layer 362 and a second electrode 37 are provided.
First, the first reflective layer 361 will be explained in detail. The first reflective layer 361 is disposed over the entire area of the second compound semiconductor layer 32 on the substrate region 2 side, with the transparent electrode 321 interposed therebetween, and spaced apart from the second compound semiconductor layer 32 . In other words, the first reflective layer 361 is disposed over the entire area of the transparent electrode 321 on the substrate region 2 side, apart from the transparent electrode 321 .
The first reflective layer 361 is made of a metal material that is conductive and has a high light reflectance of 75% or more for blue light with a wavelength of 400 nm, for example. That is, the first reflective layer 361 is configured to supply the second compound semiconductor layer 32 with the current necessary for light emission of the light emitting element 30 and to reliably reflect the light emitted from the active layer 33.

The first reflective layer 361 is made of, for example, Al (preferably pure Al). For example, Al has a reflectance of 92.5% for blue light when the thickness is 75 nm. Further, for blue light, the reflectance starts to decrease when the thickness of Al becomes less than 50 nm. For this reason, the thickness of the first reflective layer 361 is formed to be, for example, 50 nm or more, and 100 nm or less from a manufacturing standpoint.
Note that the first reflective layer 361 may be formed of one or more materials other than Al, such as selected from Al alloy, Ag, and Ag alloy.

Here, in the light emitting element 30, the light emitted from the active layer 33 passes through the second compound semiconductor layer 32, reaches the first reflective layer 361, and is reflected by the first reflective layer 361. The reflected light passes through each of the second compound semiconductor layer 32, the active layer 33, and the first compound semiconductor layer 31, and is emitted. Therefore, the light before and after reflection from the first reflective layer 361 is not attenuated by interference, but is instead amplified, and the thickness of the second compound semiconductor layer 32 is set to a thickness that ultimately amplifies the light extraction efficiency. is set.

(3-4) Configuration of the first electrode 363 The first electrode 363 is disposed between the second compound semiconductor layer 32 and the first reflective layer 361. In the first embodiment, the first electrode 363 is disposed between the transparent electrode 321 and the first reflective layer 361. The first electrode 363 is configured to electrically connect a portion of each of the second compound semiconductor layer 32 or the transparent electrode 321, and the first reflective layer 361.
The first electrode 363 is used as a contact metal. In contrast to the direct connection between the first reflective layer 361 and the transparent electrode 321, when the first reflective layer 361 is connected to the transparent electrode 321 with the first electrode 363 interposed, good electrical continuity can be obtained. .
The first electrode 363 is made of, for example, Ti or a Ti alloy. The thickness of the first electrode 363 is, for example, 10 nm or more and 100 nm or less.

As shown in FIG. 4, here, seven first electrodes 363 are provided for one first reflective layer 361 in plan view. To explain in detail, the first electrode 363 has a circular planar shape. One first electrode 363 is arranged at the center position of the first reflective layer 361 having a hexagonal shape in plan view, and six first electrodes 363 are arranged at equal intervals at peripheral positions corresponding to each of the contour corners of the first reflective layer 361. are arranged.
The total area of the seven first electrodes 363 when viewed from the thickness direction is smaller than the area of the first reflective layer 361 when viewed from the same direction. Specifically, the total area of the first electrodes 363 is set to be 1% or more and 30% or less of the area of the first reflective layer 361.
When the first electrode 363 is formed with such an area ratio, the voltage drop due to the first electrode 363 is suppressed to, for example, 10 mV or less, and the drive current of the light emitting element 30 is not affected. Further, the reflectance of the first electrode 363 is lower than the reflectance of the first reflective layer 361. In other words, since the area of the first electrode 363 covering the first reflective layer 361 is small, the area of the first reflective layer 361 contributing to reflection increases, and the decrease in light extraction efficiency can be suppressed to 30% or less.

Note that the planar shape of the first electrode 363 is not limited to a circular shape. The planar shape of the first electrode 363 may be an ellipse, a triangle, a rectangle, a polygon of pentagon or more, a slit, or the like.

(3-5) Configuration of the insulator 364 As shown in FIG. 3, the insulator 364 is disposed around the first electrode 363 between the first reflective layer 361 and the transparent electrode 321. In other words, the insulator 364 is disposed between the first reflective layer 361 and the transparent electrode 321, except for the region where the first electrode 363 is disposed. The insulator 364 has light transmittance and insulation properties, and is used as a barrier layer that separates the first reflective layer 361 and the transparent electrode 321.
The insulator 364 is made of, for example, aluminum oxide (AlO) or SiO. The thickness of the insulator 364 is effectively the same as the thickness of the first electrode 363. The insulator 364 is formed by, for example, an atomic layer deposition (ALD) method.

(3-5) Structure of the second reflective layer 362 As shown in FIGS. 1 and 3, the second reflective layer 362 includes the first compound semiconductor layer 31, the active layer 33, and the second compound semiconductor layer in side view. 32 along and surrounding the side surfaces of the mesa shape. An insulator 341 is formed between the second reflective layer 362 and the first compound semiconductor layer 31, active layer 33, and second compound semiconductor layer 32. The insulator 341 is made of, for example, SiO or SiN.
The second reflective layer 362 reflects the light emitted from the active layer 33 and the light reflected from the first reflective layer 361 toward the first compound semiconductor layer 31 side, thereby improving light extraction efficiency.

In the first embodiment, the second reflective layer 362 is formed in the same layer and made of the same material as the first reflective layer 361. Furthermore, the second reflective layer 362 is formed continuously and integrally with the first reflective layer 361.

(3-6) Configuration of the second electrode 37 As shown in FIGS. 1 and 3, the second electrode 37, the plug wiring 38, and the wiring 39 are sequentially arranged in the first reflective layer 361. .
First, the second electrode 37 will be explained. The second electrode 37 is formed on the opposite side of the first reflective layer 361 from the second compound semiconductor layer 32 . As shown in FIG. 3, the second electrode 37 is formed over the entire area of the first reflective layer 361 and has an area slightly larger than the area of the first reflective layer 361 in plan view and side view. There is. The second electrode 37 is electrically connected to the second compound semiconductor layer 32 via the first reflective layer 361, the first electrode 363, and the transparent electrode 321, respectively.

In the first embodiment, the second electrode 37 is formed by sequentially laminating a barrier metal layer 371, an Al alloy layer 372, and a barrier metal layer 373.
The barrier metal layer 371 is made of, for example, titanium nitride (TiN), and has a thickness of 10 nm or more and 100 nm or less.
For the Al alloy layer 372, for example, AlCu, which is Al with Cu added thereto, or AlSi, which is Al with Si added, is used. The amount of Cu added is, for example, 1% or more and 3% or less. The amount of Si added is, for example, 1% or more and 5% or less. The Al alloy layer 372 is formed to have a thickness of, for example, 300 nm or more and 800 nm or less.
Like the barrier metal layer 371, the barrier metal layer 373 is made of, for example, TiN, and has a thickness of 10 nm or more and 100 nm or less.

(3-7) Configuration of Plug Wiring 38 One end of the plug wiring 38 is electrically connected to the second electrode 37, and the other end of the plug wiring 38 is electrically connected to the wiring 39. The plug wiring 38 is disposed at the center of the first reflective layer 361 and is formed to penetrate the insulator 34.
The plug wiring 38 is made of W, for example.

(3-8) Structure of Wiring 39 The wiring 39 is formed by sequentially laminating a barrier metal layer 391, an Al alloy layer 392, and a barrier metal layer 393.
The barrier metal layer 391 is made of, for example, TiN, like the barrier metal layer 371. The barrier metal layer 391 is formed to have a thickness of, for example, 10 nm or more and 100 nm or less.
The Al alloy layer 392 is made of, for example, AlCu or AlSi. The Al alloy layer 392 is formed with a thickness of, for example, 500 nm or more and 600 nm or less.
Like the barrier metal layer 371, the barrier metal layer 393 is made of, for example, TiN, and has a thickness of, for example, 10 nm or more and 100 nm or less.

Note that each of the barrier metal layer 391 and the barrier metal layer 393 of the wiring 39 may be formed of a composite film in which Ti, TiN, and Ti are sequentially laminated, instead of TiN. In this case, Ti is formed to have a thickness of, for example, 30 nm or less. Further, TiN is formed to have a thickness of, for example, 10 nm or more and 100 nm or less.

As shown in FIG. 1, the wiring 39 is connected to the third terminal 390 of the light emitter region 3. The third terminal 390 is formed on the surface of the insulator 34 on the substrate region 2 side. The third terminal 390 is made of, for example, Cu, like the first terminal 281 described above.
The third terminal 390 is joined to the first terminal 281 and is electrically connected to the first terminal 281.

(3-9) Configuration of element isolation region 300 Furthermore, as shown in FIG. A second reflective layer 362 is disposed between the second reflective layer 34 and the second reflective layer 362 . The insulator 34 and the second reflective layer 362 construct an element isolation region 300 that optically isolates adjacent light emitting elements 30.

(3-10) Configuration of transparent electrode 311 As shown in FIG. 1, the transparent electrode 311 is disposed on the opposite side of the first compound semiconductor layer 31 of the light emitting element 30 from the second compound semiconductor layer 32. There is. The transparent electrode 311 is electrically connected to the first compound semiconductor layer 31. The transparent electrode 311 is made of the same material as the transparent electrode 321 described above.
Furthermore, a wiring 312 that supplies current to the first compound semiconductor layer 31 through the transparent electrode 311 is electrically connected to the transparent electrode 311 . The wiring 312 is made of W, for example.

(4) Configuration of Color Conversion Area 4 As shown in FIG. 1, the color conversion area 4 includes a color conversion layer 40, a third reflective layer 401, and partition walls 41.
The color conversion layer 40 is disposed on the light emitting surface of the light emitting element 30, that is, on the transparent electrode 311, with an insulator (not shown) interposed therebetween. The color conversion layer 40 is provided for each light emitting element 30. The color conversion layer 40 converts the light emitted from the light emitting element 30 into a specific color. Here, the light emitting element 30 is configured to emit blue light, as described above. For this reason, a color conversion layer 40 (R) that converts blue light to red light, a color conversion layer 40 (G) that converts blue light to green light, and a transparent color conversion layer 40 (B) that allows blue light to pass through as is. , T) are provided. The color conversion layer 40 is made of, for example, a resin material.
The light emitting device 1 according to the first embodiment configured as described above is constructed as a color light emitting device. More practically, the light-emitting device 1 is constructed as a color image display device or as a micro-light-emitting device (micro-LED).

The third reflective layer 401 is disposed along the periphery of the side surface of the color conversion layer 40. The third reflective layer 401 reflects the light emitted from the light emitting element 30 and the light diffused from the color conversion layer 40, thereby improving light extraction efficiency. The third reflective layer 401 is made of, for example, the same material as the first reflective layer 361.

In the color conversion region 4, partition walls 41 are formed between the color conversion layers 40 adjacent in the planar direction and between the adjacent third reflective layers 401. The partition wall 41 is configured to optically separate the color conversion layers 40 and to hold the color conversion layers 40. The partition wall 41 is made of, for example, SiO or SiN.

(5) Configuration of filter area 5 A filter area 5 is arranged on the color conversion area 4. Here, in the filter region 5, a distributed reflection layer (DBR: Distributed Bragg Reflector) 50 and a color filter 51 are sequentially laminated from the color conversion region 4 side. The distributed reflection layer 50 reflects light of a specific color. Color filter 51 absorbs light of a specific color. Here, the specific emitted light color is, for example, blue light.

(6) Configuration of optical system area 6 On the filter area 5, the optical system area 6 is arranged. An on-chip lens 60 is provided in the optical system area 6. In the on-chip lens 60, a plurality of optical lenses arranged for each light emitting element 30 are integrally formed. The optical lens has a cross-sectional shape that protrudes and curves in the light emission direction. The on-chip lens 60 is made of, for example, a resin material or an inorganic material.

[Method for manufacturing light emitting device 1]
Next, a method for manufacturing the light emitting device 1 according to the first embodiment will be briefly described.
5 to 12 show cross sections of an example for explaining each step of the method for manufacturing the light emitting device 1 according to the first embodiment.

First, a support substrate 90 is prepared (see FIG. 5). For example, a sapphire substrate is used as the support substrate 90. A first compound semiconductor layer (n-GaN) 31, an active layer 33, and a second compound semiconductor layer (p-GaN) 32 are sequentially formed on the support substrate 90 (see FIG. 5). Subsequently, a transparent electrode 321 is formed on the second compound semiconductor layer 32 (see FIG. 5).
As shown in FIG. 5, a mask 901 is formed on the transparent electrode 321. Mask 901 is used as an etching mask for forming a mesa shape. The mask 901 is formed of, for example, a single layer film of SiO, SiN, etc., or a composite film containing them.

As shown in FIG. 6, the transparent electrode 321, the second compound semiconductor layer 32, the active layer 33, and the first compound semiconductor layer 31 are etched using the mask 901. By this etching, the transparent electrode 321, the second compound semiconductor layer 32, the active layer 33, and the first compound semiconductor layer 31 are formed into a mesa shape. For example, dry etching is used for the etching. After this, mask 901 is removed.

As shown in FIG. 7, an insulator 341 is formed along the top and side surfaces of the mesa shape. The insulator 341 is formed using, for example, a chemical vapor deposition (CVD) method.

Next, an opening 341H is formed in a part of the insulator 341 on the upper surface of the mesa shape, and the surface of the transparent electrode 321 is exposed (see FIG. 8). The opening 341H is formed using photolithography and etching techniques.
Subsequently, an insulator 364 is formed on the transparent electrode 321 within the opening 341H (see FIGS. 9 and 3). The insulator 364 is made of AlO or SiO, for example, as described above. The insulator 364 is formed by, for example, an ALD method.
Next, an opening 364H is formed in the insulator 364 in the region where the first electrode 363 is formed, and the surface of the transparent electrode 321 is exposed (see FIGS. 9 and 3). The opening 364H is formed using, for example, photolithography and etching techniques.

As shown in FIG. 8, a first electrode 363 is formed in the opening 341H to be electrically connected to a portion of the surface of the transparent electrode 321 through the opening 364H. As described above, the first electrode 363 is made of, for example, Ti or a Ti alloy. The first electrode 363 is formed into a film using, for example, a sputtering method, and then patterned using an etching technique to form a predetermined shape.
Note that in FIGS. 8 to 12, one first electrode 363 is shown in order to simplify the cross-sectional shape, but as shown in FIG. 4 described above, the first electrode 363 is Seven pieces are arranged in this form.

As shown in FIG. 9, a first reflective layer 361 is formed on the first electrode 363 and the insulator 364 within the opening 341H. Then, in the same manufacturing process as the first reflective layer 361, a second reflective layer 362 is formed on the insulator 341 along the mesa-shaped sidewall. The first reflective layer 361 and the second reflective layer 362 are formed of Al deposited using a CVD method, for example.

As shown in FIG. 10, a second electrode 37 is formed on the first reflective layer 361. As described above, the second electrode 37 is formed by sequentially stacking the barrier metal layer 371, the Al alloy layer 372, and the barrier metal layer 373. These are deposited using, for example, a sputtering method, and patterned using an etching technique after the deposition.
As shown in FIG. 11, an insulator 34 embedding the second electrode 37 is formed. Then, a plug wiring 38 is formed on the insulator 34, and a wiring 39 is formed on the insulator 34, as shown in FIG.

When these steps are completed, the light emitting device 30 is substantially completed. Thereafter, as shown in FIG. 1 described above, the third terminal 390 is formed on the light emitting element 30. After bonding the substrate region 2, the light emitting element 30 is peeled off from the support substrate 90. After peeling, the color conversion region 4, filter region 5, and optical system region 6 are each formed in sequence, and the light emitting device 1 according to the first embodiment is completed.

[Effect]
As shown in FIGS. 1, 3, and 4, the light emitting device 1 according to the first embodiment includes a first compound semiconductor layer 31, an active layer 33, a second compound semiconductor layer 32, and a first reflective layer 31. A layer 361 and a first electrode 363 are provided.
The first compound semiconductor layer 31 has a first conductivity type. The active layer 33 is stacked on the first compound semiconductor layer 31 . The second compound semiconductor layer 32 is stacked on the side of the active layer 33 opposite to the first compound semiconductor layer 31, and has a second conductivity type opposite to the first conductivity type.
The first reflective layer 361 is spaced apart from the surface of the second compound semiconductor layer 32 opposite to the active layer 33 and reflects light emitted from the active layer 33 . The first electrode 363 is disposed between the second compound semiconductor layer 32 and the first reflective layer 361 and electrically connects a portion of each of the second compound semiconductor layer 32 and the first reflective layer 361. do.
In the light emitting device 1 configured as described above, the first reflective layer 361 is provided on the surface of the second compound semiconductor layer 32, so that light emitted from the active layer 33 is prevented from leaking to the drive circuit 21 side. can be effectively suppressed or prevented. In particular, since the first reflective layer 361 is disposed over the entire surface of the second compound semiconductor layer 32, there is no light leakage. Since the first reflective layer 361 can reflect light efficiently, the light extraction efficiency of the light emitting device 1 can be improved.
As a result of being able to improve the light extraction efficiency, even if the light emitting element 30 is further miniaturized, the image quality of the image display device can be improved.
Furthermore, since the first reflective layer 361 is connected to the second compound semiconductor layer 32 with the first electrode 363 interposed, the supply of current from the first reflective layer 361 side is improved, and the luminous efficiency of the light emitting element 30 is improved. can be improved.
In addition, since the first electrode 363 is electrically connected to a portion of each of the first reflective layer 361 and the second compound semiconductor layer 32, a sufficient reflective area of the first reflective layer 361 can be ensured. Can be done. Therefore, the light emitting device 1 can further improve the light extraction efficiency.
Furthermore, since the first reflective layer 361 can block light leakage to the drive circuit 21 side, malfunctions of the drive circuit 21 due to light leakage can be effectively suppressed or prevented. Therefore, the operational reliability of the light emitting device 1 can be improved.

Furthermore, in the light emitting device 1, as shown in FIGS. 1 to 4, the first reflective layer 361 is made of one or more materials selected from Al, Al alloy, Ag, and Ag alloy.
For example, when the thickness of the first reflective layer 361 is 75 nm, the reflectance of blue light having a wavelength of 400 nm is 92.5% for Al and 91.5% for Al alloy (AlCu). , 86.2% for Ag and 84.0% for Ag alloy. That is, since the reflectance of the first reflective layer 361 is set to 75% or more, the light extraction efficiency of the light emitting device 1 can be further improved.

In addition, the light emitting device 1 further includes a transparent electrode 321 between the second compound semiconductor layer 32 and the first electrode 363, as shown in FIG. and is electrically connected to the second compound semiconductor layer 32.
Therefore, a good electrical connection between the second compound semiconductor layer 32 and the transparent electrode 321 can be obtained, and as a result, a good electrical connection can be obtained between the first reflective layer 361 and the second compound semiconductor layer 32. .

Furthermore, in the light emitting device 1, as particularly shown in FIG. 3, the first electrode 363 is made of Ti or a Ti alloy. Therefore, good electrical connection between the first reflective layer 361 and the transparent electrode 321 can be obtained.

Furthermore, in the light emitting device 1, as shown in FIGS. 3 and 4, the total area of the first electrode 363 viewed from the thickness direction is smaller than the area of the first reflective layer 361 viewed from the same direction. Specifically, the total area of the first electrodes 363 is 1% or more and 30% or less of the area of the first reflective layer 361.
When the first electrode 363 is formed with such an area ratio, the voltage drop due to the first electrode 363 is suppressed, and the drive current of the light emitting element 30 is not affected. In addition, the area of the first electrode 363 that covers the first reflective layer 361 is reduced, and the reflective area of the first reflective layer 361 can be increased, so that light extraction efficiency can be improved.

In addition, as shown in FIG. 3 in particular, the light emitting device 1 also includes a transparent electrode 321 and a first reflective layer between the second compound semiconductor layer 32 and the first reflective layer, specifically, excluding the first electrode 363 An insulator 364 is provided between the reflective layer 361 and the reflective layer 361 . The insulator 364 has optical transparency and insulating properties.
Therefore, compositional changes in the first reflective layer 361 caused by the transparent electrode 321 can be effectively suppressed or prevented, so that the reflectance of the first reflective layer 361 can be maintained and the light extraction efficiency can be improved. can.

Further, in the light emitting device 1, as particularly shown in FIG. 3, the second compound semiconductor layer 32 is formed to have a thickness that increases the light extraction efficiency. In other words, the second compound semiconductor layer 32 has an appropriate thickness so that the light emitted from the active layer 33 toward the first compound semiconductor layer 31 is not attenuated by the light that is reflected by the first reflective layer 361 and reaches the active layer 33. It is formed.
In the light emitting device 1 configured in this manner, light extraction efficiency can be improved.

Further, in the light emitting device 1, as particularly shown in FIG. 3, at least a portion of the first compound semiconductor layer 31, the active layer 33, and the second compound semiconductor layer 32 have a mesa shape. In the light emitting device 1, a second reflective layer 362 is disposed along the side surface of the mesa shape. The second reflective layer 362 reflects the light emitted from the active layer 33 and the light reflected from the first reflective layer 361 toward the first compound semiconductor layer 31 side.
Therefore, in the light emitting device 1, light can be extracted efficiently by the second reflective layer 362, so that the light extraction efficiency can be further improved.

Further, in the light emitting device 1, as particularly shown in FIG. 3, the second reflective layer 362 is formed in the same layer and made of the same material as the first reflective layer 361. In addition, the second reflective layer 362 is integrally formed with the first reflective layer 361.
Therefore, the structure of the light emitting device 1 can be simplified.

In addition, in the method for manufacturing the light emitting device 1, as shown in FIG. 9, the first reflective layer 361 and the second reflective layer 362 are formed in the same process.
Therefore, one of the originally required steps of forming the first reflective layer 361 and the second reflective layer 362 can be omitted, which reduces the number of manufacturing steps in the method of manufacturing the light emitting device 1. be able to.

Further, the light emitting device 1 includes a second electrode 37, as shown in FIGS. 1 and 3. The second electrode 37 is disposed on the opposite side of the first reflective layer 361 from the second compound semiconductor layer 32 . The second electrode 37 is formed by sequentially stacking a barrier metal layer 371, an Al alloy layer 372, and a barrier metal layer 373. The second electrode 37 configured in this manner can improve electrical reliability as an electrode.

<2. Second embodiment>
A light emitting device 1 according to a second embodiment of the present disclosure will be described using FIGS. 13 to 15. Note that in the second embodiment and subsequent embodiments, the same or substantially the same components as those of the light emitting device 1 according to the first embodiment are denoted by the same reference numerals. However, duplicate explanations will be omitted.

[Configuration of light emitting device 1]
FIG. 13 shows an example of the configuration of the first reflective layer 361 and first electrode 363 of the light emitting element 30 in the light emitting device 1 according to the second embodiment.
As shown in FIG. 13, in the light emitting device 1, one first electrode 363 is disposed at the center of the first reflective layer 361 of the light emitting element 30 in plan view. The total area ratio of the first electrode 363 to the first reflective layer 361 is the same as the area ratio of the light emitting device 1 according to the first embodiment. Further, the planar shape of the first electrode 363 is the same as the planar shape of the first electrode 363 of the light emitting device 1 according to the first embodiment.

Components other than those described above are the same as those of the light emitting device 1 according to the first embodiment, so a description thereof will be omitted here.

[Effect]
According to the light emitting device 1 according to the second embodiment, the same effects as those obtained by the light emitting device 1 according to the first embodiment can be obtained.

[First modification]
FIG. 14 shows an example of the configuration of the first reflective layer 361 and the first electrode 363 of the light emitting element 30 in the light emitting device 1 according to the first modification of the second embodiment.
As shown in FIG. 14, in the light emitting device 1 according to the first modification, a total of four first electrodes 363, two in the direction of the arrow X and two in the direction of the arrow Y, are arranged on the first reflective layer 361. It is set up.
Components other than those described above are the same as those of the light emitting device 1 according to the first embodiment, so description thereof will be omitted here.

[Effect]
According to the light emitting device 1 according to the first modification, the same effects as those obtained by the light emitting device 1 according to the first embodiment can be obtained.

[Second modification]
FIG. 15 shows an example of the configuration of the first reflective layer 361 and the first electrode 363 of the light emitting element 30 in the light emitting device 1 according to the second modification of the second embodiment.
As shown in FIG. 15, in the light emitting device 1 according to the second modification, the first electrode 363 is located at peripheral positions corresponding to each of the contour corners of the first reflective layer 361, which has a hexagonal shape in plan view. Six pieces are placed at intervals.
Components other than those described above are the same as those of the light emitting device 1 according to the first embodiment, so description thereof will be omitted here.

[Effect]
According to the light emitting device 1 according to the second modification, the same effects as those obtained by the light emitting device 1 according to the first embodiment can be obtained.

<3. Third embodiment>
A light emitting device 1 according to a third embodiment of the present disclosure will be described using FIGS. 16 and 17.
FIG. 16 shows an example of an enlarged cross-sectional configuration of the light emitting element 30 that constructs the light emitting device 1 according to the third embodiment. FIG. 17 shows an example of the configuration of the first reflective layer 361 and the first electrode 363 of the light emitting element 30.

[Configuration of light emitting device 1]
As shown in FIGS. 16 and 17, in the light emitting device 1 according to the third embodiment, a transparent electrode 321 (see FIG. 3) is provided between the second compound semiconductor layer 32 and the first reflective layer 361 of the light emitting element 30. ) is not provided. The first reflective layer 361 is directly connected to the second compound semiconductor layer 32 with a first electrode 363 interposed therebetween.
Since the transparent electrode 321 is not provided, the first electrode 363 is made of, for example, Ni, Pd, or Cr. These materials are materials that can be electrically connected to the second compound semiconductor layer 32 with low resistance. In other words, the first electrode 363 achieves good electrical continuity with the second compound semiconductor layer 32.

As shown in FIG. 17, the first electrodes 363 are formed in the same arrangement and number as the first electrodes 363 shown in FIG. 4 of the light emitting device 1 according to the first embodiment. Note that the first electrodes 363 may be formed in the same arrangement and number as the first electrodes 363 shown in each of FIGS. 13, 14, and 15 of the light emitting device 1 according to the second embodiment.

[Effect]
According to the light emitting device 1 according to the third embodiment, the same effects as those obtained by the light emitting device 1 according to the first embodiment can be obtained.

<4. Fourth embodiment>
A light emitting device 1 according to a fourth embodiment of the present disclosure will be described using FIGS. 18 and 19.
FIG. 18 shows an example of an enlarged cross-sectional configuration of the light emitting element 30 that constructs the light emitting device 1 according to the fourth embodiment. FIG. 19 shows an example of the configuration of the first reflective layer 361 and the first electrode 363 of the light emitting element 30.

[Configuration of light emitting device 1]
As shown in FIGS. 18 and 19, in the light emitting device 1 according to the fourth embodiment, the second reflective layer 362 is electrically isolated from the first reflective layer 361. To explain in detail, an insulator 342 is formed between the second reflective layer 362 and the first reflective layer 361. The second reflective layer 362 is in an electrically floating state.

The second reflective layer 362 is formed in the same layer as the first reflective layer 361 and made of the same material, similarly to the second reflective layer 362 of the light emitting device 1 according to the first embodiment described above. ing. Further, the second reflective layer 362 may be formed as a separate layer from the first reflective layer 361 and may be formed of a different material.

[Effect]
According to the light emitting device 1 according to the fourth embodiment, the same effects as those obtained by the light emitting device 1 according to the first embodiment can be obtained.

Furthermore, in the light emitting device 1, as shown in FIG. 18, the second reflective layer 362 is electrically isolated from the first reflective layer 361. With this configuration, the second compound semiconductor layer 32, the active layer 33, and the first compound semiconductor layer 31 are connected to one electrode, and the insulator 341 is connected to the current path from the first reflective layer 361 to the second compound semiconductor layer 32. No parasitic capacitance is added using the dielectric and the second reflective layer 362 as the other electrode. Therefore, the driving operation speed of the light emitting element 30 can be increased.

<5. Fifth embodiment>
A light emitting device 1 according to a fifth embodiment of the present disclosure will be described using FIG. 20.
FIG. 20 shows an example of an enlarged cross-sectional configuration of the light emitting element 30 that constructs the light emitting device 1 according to the fifth embodiment.

[Configuration of light emitting device 1]
As shown in FIG. 20, in the light emitting device 1 according to the fifth embodiment, the second electrode 37 is disposed on the first reflective layer 361, similarly to the light emitting device 1 according to the first embodiment. . The second electrode 37 is different from the second electrode 37 of the light emitting device 1 according to the first embodiment, and is formed of a single barrier metal layer. For example, TiN is used as the barrier metal layer.

Components other than those described above are the same as those of the light emitting device 1 according to the first embodiment, so description thereof will be omitted here.
Note that in the fifth embodiment, the first reflective layer 361 may be formed of an Al alloy, although there is a slight decrease in reflectance. As the Al alloy, for example, AlCu can be practically used.

[Effect]
According to the light emitting device 1 according to the fifth embodiment, the same effects as those obtained by the light emitting device 1 according to the first embodiment can be obtained.

Furthermore, in the light emitting device 1, as shown in FIG. 20, the second electrode 37 is formed of a single barrier metal layer, so that the structure can be simplified.

<6. Example of application to mobile objects>
The technology according to the present disclosure (this technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as a car, electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personal mobility, airplane, drone, ship, robot, etc. It's okay.

FIG. 21 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in FIG. 21, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside vehicle information detection unit 12030, an inside vehicle information detection unit 12040, and an integrated control unit 12050. Further, as the functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio/image output section 12052, and an in-vehicle network I/F (Interface) 12053 are illustrated.

The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 includes a drive force generation device such as an internal combustion engine or a drive motor that generates drive force for the vehicle, a drive force transmission mechanism that transmits the drive force to wheels, and a drive force transmission mechanism that controls the steering angle of the vehicle. It functions as a control device for a steering mechanism to adjust and a braking device to generate braking force for the vehicle.

The body system control unit 12020 controls the operations of various devices installed in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as a headlamp, a back lamp, a brake lamp, a turn signal, or a fog lamp. In this case, radio waves transmitted from a portable device that replaces a key or signals from various switches may be input to the body control unit 12020. The body system control unit 12020 receives input of these radio waves or signals, and controls the door lock device, power window device, lamp, etc. of the vehicle.

The external information detection unit 12030 detects information external to the vehicle in which the vehicle control system 12000 is mounted. For example, an imaging section 12031 is connected to the outside-vehicle information detection unit 12030. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the exterior of the vehicle, and receives the captured image. The external information detection unit 12030 may perform object detection processing such as a person, car, obstacle, sign, or text on the road surface or distance detection processing based on the received image.

The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of received light. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. Further, the light received by the imaging unit 12031 may be visible light or non-visible light such as infrared rays.

The in-vehicle information detection unit 12040 detects in-vehicle information. For example, a driver condition detection section 12041 that detects the condition of the driver is connected to the in-vehicle information detection unit 12040. The driver condition detection unit 12041 includes, for example, a camera that images the driver, and the in-vehicle information detection unit 12040 detects the degree of fatigue or concentration of the driver based on the detection information input from the driver condition detection unit 12041. It may be calculated, or it may be determined whether the driver is falling asleep.

The microcomputer 12051 calculates control target values for the driving force generation device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, Control commands can be output to 12010. For example, the microcomputer 12051 realizes ADAS (Advanced Driver Assistance System) functions, including vehicle collision avoidance or impact mitigation, following distance based on vehicle distance, vehicle speed maintenance, vehicle collision warning, vehicle lane departure warning, etc. It is possible to perform cooperative control for the purpose of

In addition, the microcomputer 12051 controls the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040. It is possible to perform cooperative control for the purpose of autonomous driving, etc., which does not rely on operation.

Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12030 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 controls the headlamps according to the position of the preceding vehicle or oncoming vehicle detected by the vehicle exterior information detection unit 12030, and performs cooperative control for the purpose of preventing glare, such as switching from high beam to low beam. It can be carried out.

The audio and image output unit 12052 transmits an output signal of at least one of audio and images to an output device that can visually or audibly notify information to the occupants of the vehicle or to the outside of the vehicle. In the example of FIG. 21, an audio speaker 12061, a display section 12062, and an instrument panel 12063 are illustrated as output devices. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

FIG. 22 is a diagram showing an example of the installation position of the imaging section 12031.

In FIG. 22, the imaging unit 12031 includes

imaging units

12101, 12102, 12103, 12104, and 12105.

The

imaging units

12101, 12102, 12103, 12104, and 12105 are provided at, for example, the front nose of the vehicle 12100, the side mirrors, the rear bumper, the back door, and the upper part of the windshield inside the vehicle. An imaging unit 12101 provided in the front nose and an imaging unit 12105 provided above the windshield inside the vehicle mainly acquire images in front of the vehicle 12100.

Imaging units

12102 and 12103 provided in the side mirrors mainly capture images of the sides of the vehicle 12100. An imaging unit 12104 provided in the rear bumper or back door mainly captures images of the rear of the vehicle 12100. The imaging unit 12105 provided above the windshield inside the vehicle is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, and the like.

Note that FIG. 22 shows an example of the imaging range of the imaging units 12101 to 12104. An imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate imaging ranges of the

imaging units

12102 and 12103 provided on the side mirrors, respectively, and an imaging range 12114 shows the imaging range of the imaging unit 12101 provided on the front nose. The imaging range of the imaging unit 12104 provided in the rear bumper or back door is shown. For example, by overlapping the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera including a plurality of image sensors, or may be an image sensor having pixels for phase difference detection.

For example, the microcomputer 12051 determines the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the temporal change in this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. By determining the following, it is possible to extract, in particular, the closest three-dimensional object on the path of vehicle 12100, which is traveling at a predetermined speed (for example, 0 km/h or more) in approximately the same direction as vehicle 12100, as the preceding vehicle. can. Furthermore, the microcomputer 12051 can set an inter-vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control), automatic acceleration control (including follow-up start control), and the like. In this way, it is possible to perform cooperative control for the purpose of autonomous driving, etc., in which the vehicle travels autonomously without depending on the driver's operation.

For example, the microcomputer 12051 transfers three-dimensional object data to other three-dimensional objects such as two-wheeled vehicles, regular vehicles, large vehicles, pedestrians, and utility poles based on the distance information obtained from the imaging units 12101 to 12104. It can be classified and extracted and used for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the degree of risk of collision with each obstacle, and when the collision risk exceeds a set value and there is a possibility of a collision, the microcomputer 12051 transmits information via the audio speaker 12061 and the display unit 12062. By outputting a warning to the driver via the vehicle control unit 12010 and performing forced deceleration and avoidance steering via the drive system control unit 12010, driving support for collision avoidance can be provided.

At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether the pedestrian is present in the images captured by the imaging units 12101 to 12104. Such pedestrian recognition involves, for example, a procedure for extracting feature points in images captured by the imaging units 12101 to 12104 as infrared cameras, and a pattern matching process is performed on a series of feature points indicating the outline of an object to determine whether it is a pedestrian or not. This is done through a procedure that determines the When the microcomputer 12051 determines that a pedestrian is present in the images captured by the imaging units 12101 to 12104 and recognizes the pedestrian, the audio image output unit 12052 creates a rectangular outline for emphasis on the recognized pedestrian. The display unit 12062 is controlled to display the . Furthermore, the audio image output unit 12052 may control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

An example of a vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 12031 among the configurations described above. By applying the technology according to the present disclosure to the imaging unit 12031, the imaging unit 12031 with a simpler configuration can be realized.

<7. Other embodiments>
The present technology is not limited to the embodiments described above, and can be modified in various ways without departing from the gist thereof. For example, two or more of the above embodiments can be combined.

In the light emitting device according to the first embodiment of the present disclosure, since the first reflective layer is provided on the second compound semiconductor layer, leakage of light emitted from the active layer can be effectively suppressed or prevented. Therefore, the first reflective layer can reflect light efficiently, so that the light extraction efficiency of the light emitting device can be improved.
Furthermore, in the light emitting device, the first electrode is electrically connected to a portion of each of the first reflective layer and the second compound semiconductor layer, so that a sufficient reflective area of the first reflective layer is ensured, and The light extraction efficiency can be improved.

A light emitting device according to a second embodiment of the present disclosure is the light emitting device according to the first embodiment, further including an insulator. The insulator is disposed between the second compound semiconductor layer and the first reflective layer, specifically between the transparent electrode and the first reflective layer, and has optical transparency and insulation properties.
Therefore, compositional changes in the first reflective layer caused by the transparent electrode can be effectively suppressed or prevented, so that the reflectance of the first reflective layer can be maintained and the light extraction efficiency can be improved.

A light emitting device according to a third embodiment of the present disclosure is a light emitting device according to the first embodiment or the second embodiment, in which at least a portion of the first compound semiconductor layer, the active layer, and the second compound semiconductor layer have a mesa shape. A second reflective layer is provided along the side surface. The second reflective layer reflects the light emitted from the active layer and the light reflected from the first reflective layer toward the first compound semiconductor layer.
Therefore, in the light emitting device, light can be extracted efficiently by the second reflective layer, so that the light extraction efficiency can be further improved.

A light emitting device according to a fourth embodiment of the present disclosure is a light emitting device according to any one of the first to third embodiments, in which a second electrode is provided on the opposite side of the first reflective layer from the second compound semiconductor layer. It further includes: The second electrode is formed by sequentially stacking a barrier metal layer, an Al alloy, and a barrier metal layer.
Therefore, in the light emitting device, the electrical reliability of the second electrode can be improved.

<Configuration of this technology>
The present technology has the following configuration. According to the following configuration of the present technology, the light extraction efficiency of the light emitting device can be improved.
(1)
a first compound semiconductor layer of a first conductivity type;
an active layer stacked on the first compound semiconductor layer;
a second compound semiconductor layer of a second conductivity type opposite to the first conductivity type, stacked on the side of the active layer opposite to the first compound semiconductor layer;
a first reflective layer that is spaced apart from the surface of the second compound semiconductor layer opposite to the active layer and that reflects light emitted from the active layer;
a first electrode that is disposed between the second compound semiconductor layer and the first reflective layer and electrically connects a portion of each of the second compound semiconductor layer and the first reflective layer;
A light-emitting device equipped with
(2)
The light emitting device according to (1), wherein the first reflective layer is made of one or more materials selected from Al, Al alloy, Ag, and Ag alloy.
(3)
further comprising a transparent electrode between the second compound semiconductor layer and the first electrode,
The light emitting device according to (1) or (2), wherein the first electrode is electrically connected to the second compound semiconductor layer with a transparent electrode interposed therebetween.
(4)
The light emitting device according to (3) above, wherein the first electrode is made of Ti or a Ti alloy.
(5)
The light emitting device according to (2) above, wherein the first electrode is made of Ni, Pd, or Cr.
(6)
The light emitting device according to any one of (1) to (5), wherein one or more first electrodes are provided.
(7)
The light emitting device according to (6), wherein the total area of the first electrode viewed from the thickness direction is smaller than the area of the first reflective layer viewed from the same direction.
(8)
The light emitting device according to (6) or (7), wherein the total area of the first electrodes is 1% or more and 30% or less of the area of the first reflective layer.
(9)
The light emitting device according to any one of (1) to (8), wherein the first reflective layer has a reflectance of 75% or more for blue light.
(10)
The method according to (1) to (9) above further includes an insulator disposed between the second compound semiconductor layer and the first reflective layer, and having a light transmittance and an insulating property. The light emitting device according to any one of the above.
(11)
The light emitting device according to (10) above, wherein the insulator is AlO, SiO, or SiN.
(12)
The light emitting device according to any one of (1) to (11), wherein the second compound semiconductor layer is formed to have a thickness that amplifies light extraction efficiency.
(13)
At least a portion of the first compound semiconductor layer, the active layer and the second compound semiconductor layer have a mesa shape,
The method further includes a second reflective layer that is disposed along a side surface of the mesa shape and reflects light emitted from the active layer and light reflected from the first reflective layer toward the first compound semiconductor layer. The light emitting device according to any one of (1) to (11) above.
(14)
The light emitting device according to (13), wherein the second reflective layer is formed in the same layer and made of the same material as the first reflective layer.
(15)
The light emitting device according to (13) or (14), wherein the second reflective layer is integrally formed with the first reflective layer.
(16)
The light emitting device according to (13), wherein the second reflective layer is electrically isolated from the first reflective layer.
(17)
The light emitting device according to (16), wherein the second reflective layer is made of a different material from the first reflective layer.
(18)
Further comprising a second electrode in which each of a barrier metal layer, an Al alloy layer, and a barrier metal layer are sequentially laminated on a side of the first reflective layer opposite to the second compound semiconductor layer. The light emitting device according to any one of (17).
(19)
The light emitting device according to (18), further comprising a wiring electrically connected to the second electrode via a plug wiring.
(20)
The first compound semiconductor layer, the active layer and the second compound semiconductor layer constitute a light emitting device,
The light emitting device according to any one of (1) to (19), wherein a plurality of the light emitting elements are arranged to construct a micro light emitting device.

This application claims priority based on Japanese Patent Application No. 2022-131103 filed on August 19, 2022 at the Japan Patent Office, and all contents of this application are incorporated herein by reference. be used for.

Various modifications, combinations, subcombinations, and changes may occur to those skilled in the art, depending on design requirements and other factors, which may come within the scope of the appended claims and their equivalents. It is understood that the

Claims

a first compound semiconductor layer of a first conductivity type;
an active layer stacked on the first compound semiconductor layer;
a second compound semiconductor layer of a second conductivity type opposite to the first conductivity type, stacked on the side of the active layer opposite to the first compound semiconductor layer;
a first reflective layer that is spaced apart from the surface of the second compound semiconductor layer opposite to the active layer and that reflects light emitted from the active layer;
a first electrode that is disposed between the second compound semiconductor layer and the first reflective layer and electrically connects a portion of each of the second compound semiconductor layer and the first reflective layer;
A light-emitting device equipped with
The light emitting device according to claim 1, wherein the first reflective layer is made of one or more materials selected from Al, Al alloy, Ag, and Ag alloy.
further comprising a transparent electrode between the second compound semiconductor layer and the first electrode,
The light emitting device according to claim 2, wherein the first electrode is electrically connected to the second compound semiconductor layer with a transparent electrode interposed therebetween.
The light emitting device according to claim 3, wherein the first electrode is made of Ti or a Ti alloy.
The light emitting device according to claim 2, wherein the first electrode is made of Ni, Pd, or Cr.
The light emitting device according to claim 1, wherein one or more first electrodes are provided.
The light emitting device according to claim 6, wherein a total area of the first electrode viewed from the thickness direction is smaller than an area of the first reflective layer viewed from the same direction.
The light emitting device according to claim 7, wherein the total area of the first electrodes is 1% or more and 30% or less of the area of the first reflective layer.
The light emitting device according to claim 1, wherein the first reflective layer has a reflectance of 75% or more for blue light.
The light emitting device according to claim 1, further comprising an insulator disposed between the second compound semiconductor layer and the first reflective layer, having light transmittance and insulation properties.
The light emitting device according to claim 10, wherein the insulator is AlO, SiO, or SiN.
The light emitting device according to claim 1, wherein the second compound semiconductor layer is formed to have a thickness that increases light extraction efficiency.
At least a portion of the first compound semiconductor layer, the active layer and the second compound semiconductor layer have a mesa shape,
The method further includes a second reflective layer that is disposed along a side surface of the mesa shape and reflects light emitted from the active layer and light reflected from the first reflective layer toward the first compound semiconductor layer. The light emitting device according to claim 1.
The light emitting device according to claim 13, wherein the second reflective layer is formed in the same layer and made of the same material as the first reflective layer.
The light emitting device according to claim 13, wherein the second reflective layer is integrally formed with the first reflective layer.
The light emitting device according to claim 13, wherein the second reflective layer is electrically isolated from the first reflective layer.
The light emitting device according to claim 16, wherein the second reflective layer is made of a different material from the first reflective layer.
2. The second electrode according to claim 1, further comprising a second electrode in which each of a barrier metal layer, an Al alloy layer, and a barrier metal layer are sequentially laminated on a side of the first reflective layer opposite to the second compound semiconductor layer. Light emitting device.
The light emitting device according to claim 18, further comprising a wiring electrically connected to the second electrode via a plug wiring.
The first compound semiconductor layer, the active layer and the second compound semiconductor layer constitute a light emitting device,
The light emitting device according to claim 1, wherein a plurality of the light emitting elements are arranged to construct a micro light emitting device.