JP7105568B2 - Semiconductor light-emitting element and light-emitting device - Google Patents

Description

The present invention relates to a semiconductor light emitting element and a light emitting device having the same.

2. Description of the Related Art Flip-chip bonding is known as one form of mounting semiconductor elements.
For example, Patent Literature 1 discloses a light-emitting device including a wiring board having a conductive member and a light-emitting element flip-chip bonded to the wiring board.

JP 2017-33967 A

According to flip-chip bonding, heat generated by the light-emitting element can be released directly from the electrode to the mounting substrate without passing through, for example, a sapphire substrate having high thermal resistance. Therefore, it is mainly used for devices that require high brightness and large current drive, such as lighting. When used in this type of device, for devices that require particularly high brightness, a mirror layer is usually arranged on the surface side (epitaxial layer side) of the substrate, and the light reflected by the mirror layer is It is taken out from the back side of the substrate. This is because the electrodes do not become an obstacle and the light can be extracted efficiently. In addition, the heat dissipation property is improved by forming the electrodes responsible for heat dissipation as large as possible over the surface area of the element.

On the other hand, for small devices such as wearable devices, which have been attracting attention in recent years, there is an increasing demand for chip size packages (CSP) that can be directly bonded to mounting substrates, and light emitting elements are no exception.
However, in the structure of the conventional light-emitting element for flip-chip bonding, the direction of light extraction is the back surface of the substrate opposite to the bonding surface of the mounting substrate. Therefore, when there is a restriction on the light extraction direction, a situation arises in which only the light emitting element must be bonded to the surface opposite to the bonding surface of the other semiconductor element. In other words, the elements are arranged on both sides of the mounting board, and the mountability to the device becomes very poor.

An object of the present invention is to provide a semiconductor light-emitting element for flip-chip bonding which is composed of a chip size package (CSP) and can extract light from the electrode side (the surface side of the substrate), and a light-emitting device having the same. is.

A semiconductor light-emitting device according to an embodiment of the present invention comprises a translucent substrate, a semiconductor multilayer structure including an n-type semiconductor layer, a light-emitting layer and a p-type semiconductor layer which are sequentially laminated on a surface of the substrate; A p-side electrode arranged on the surface side of the multilayer structure and electrically connected to the p-type semiconductor layer and the p-side electrode on the surface side of the semiconductor multilayer structure are arranged to transmit light from the light emitting layer. an n-side electrode electrically connected to the n-type semiconductor layer and arranged with a light extraction region for light extraction; and a mirror layer formed on the back surface of the substrate so as to face at least the light extraction region. It consists of a chip size package (CSP), including

According to this configuration, the light generated in the light-emitting layer can be extracted from the semiconductor laminated structure side by reflecting it on the mirror layer on the back surface of the substrate. Moreover, since the light extraction region is provided between the p-side electrode and the n-side electrode so as not to obstruct light as much as possible, a relatively sufficient light extraction efficiency can be achieved.
As a result, when the semiconductor light emitting device is flip-chip bonded to the mounting substrate, light can be extracted to the bonding surface (the surface facing the semiconductor light emitting device) of the mounting substrate. Therefore, for example, other semiconductor elements (e.g., switching elements, sensor elements, passive elements, etc.) different from the semiconductor light emitting element are arranged on one surface of the mounting substrate, and the light extraction direction is the other surface of the mounting substrate. Even if there is a restriction on the side, the semiconductor light emitting device can be arranged on one side of the mounting board in the same manner as other semiconductor devices. As a result, all the semiconductor elements can be arranged on one surface side of the mounting board, so that it is possible to prevent deterioration in the mountability of the mounting board to the device.

In the semiconductor light emitting device according to one embodiment of the present invention, the semiconductor laminated structure includes a mesa structure portion having a wall surface extending from the p-type semiconductor layer through the light emitting layer to the n-type semiconductor layer, and the mesa structure portion. and a low stepped portion having an upper surface where the n-type semiconductor layer is exposed, and the light extraction region may include an upper surface region of the mesa structure.
In the semiconductor light emitting device according to one embodiment of the present invention, the p-side electrode is arranged on the upper surface of the mesa structure portion, and the n-side electrode is arranged on the upper surface of the low step portion. good too.

In a semiconductor light emitting device according to an embodiment of the present invention, the semiconductor laminated structure is formed in a quadrangular shape having a first end surface and a second end surface facing each other in a plan view, and the mesa structure portion includes the The electrode region for the n-side electrode is formed to be biased toward the second end face so that the electrode region for the n-side electrode is empty between the first end face, and the n-side electrode is arranged on the upper surface of the electrode region, The p-side electrode may be arranged closer to the second end surface on the upper surface of the mesa structure.

In the semiconductor light emitting device according to one embodiment of the present invention, the n-side electrode and the p-side electrode are provided at the first end surface side end portion and the second end surface side end portion of the semiconductor multilayer structure, respectively. They may be arranged one by one.
In the semiconductor light emitting device according to one embodiment of the present invention, the plurality of n-side electrodes are arranged at intervals along the first end face at the end portion of the semiconductor multilayer structure on the first end face side. A plurality of the p-side electrodes may be arranged at intervals along the second end face at the end of the semiconductor multilayer structure on the second end face side.

In a semiconductor light emitting device according to an embodiment of the present invention, the semiconductor laminated structure is formed in a quadrangular shape having a first end surface and a second end surface facing each other in a plan view, and the mesa structure portion includes the The semiconductor lamination is arranged such that the first electrode region for the n-side electrode is spaced between itself and the first end surface, and the second electrode region for the p-side electrode is spaced between it and the second end face. An insulating film is formed so as to cover the upper surface and the wall surface of the mesa structure and the upper surface of the second electrode region, and the n-side electrode is formed in a central portion of the structure. The p-side electrode is arranged on the upper surface of the second electrode region with the insulating film interposed therebetween, the p-side electrode and the mesa are formed on the insulating film. A wiring film may be further included for connecting the p-type semiconductor layer exposed to the upper surface of the structural portion.

In the semiconductor light emitting device according to one embodiment of the present invention, the wiring film includes a transparent electrode film, and the transparent electrode film is disposed in the central portion of the upper surface of the mesa structure through the opening of the insulating film. It may be connected to the p-type semiconductor layer.
By using a transparent electrode film, it is possible to extract light from the contact region of the transparent electrode film as well, so that a decrease in light extraction efficiency can be suppressed.

In the semiconductor light emitting device according to one embodiment of the present invention, the substrate may include a sapphire substrate.
A light-emitting device according to an embodiment of the present invention includes a mounting substrate having one surface and the other surface and including a light transmitting portion through which light can be transmitted from the one surface to the other surface; and the semiconductor light emitting element flip-chip bonded to the one surface of the mounting substrate so as to face the light transmitting portion.

According to this configuration, light generated by the semiconductor light emitting element on one surface of the mounting substrate can be extracted to the other surface of the mounting substrate through the light transmitting portion.
The light-emitting device according to one embodiment of the present invention may further include another semiconductor element arranged on the one surface of the mounting substrate and having a function different from that of the semiconductor light-emitting element.
According to this configuration, all the semiconductor elements can be arranged on one surface side of the mounting board, so that it is possible to prevent deterioration in the mountability of the mounting board to the device.

In the light-emitting device according to one embodiment of the present invention, the mounting substrate may be made of an opaque plate material, and the light transmission part may include an opening penetrating through the opaque plate material. .
The light emitting device according to one embodiment of the present invention may further include a convex lens formed on the other surface of the mounting substrate so as to cover the opening.

As a result, the light extracted to the other side of the mounting substrate can be scattered.
In the light-emitting device according to one embodiment of the present invention, the mounting substrate is made of a transparent plate material, and the light transmitting portion includes a portion of the transparent plate material facing the light extraction region. good.
According to this configuration, since the entire mounting substrate is light transmissive, light from the semiconductor light emitting element can be reliably extracted even if the semiconductor light emitting element is bonded to the mounting substrate while being displaced from the mounting substrate.

In the light-emitting device according to one embodiment of the present invention, the mounting substrate may have, on the other surface, a convex lens portion integrally formed with the light transmitting portion.
The light-emitting device according to one embodiment of the present invention may further include a sealing resin formed on the one surface side of the mounting substrate so as to cover the semiconductor light-emitting element.

FIG. 1 is a schematic plan view of a semiconductor light emitting device according to one embodiment of the invention. FIG. 2 is a sectional view showing a II-II section of FIG. FIG. 3 is a schematic perspective view of a light emitting device (wristband) according to one embodiment of the present invention. 4 is a diagram schematically showing the internal structure of the light emitting device of FIG. 3. FIG. FIG. 5 is a reference diagram for comparison with the internal structure of FIG. FIG. 6 is a diagram showing a modification of the semiconductor light emitting device of FIG. FIG. 7 is a diagram showing a modification of the semiconductor light emitting device of FIG. FIG. 8 is a diagram showing a modification of the semiconductor light emitting device of FIG. FIG. 9 is a diagram showing a modification of the semiconductor light emitting device of FIG. FIG. 10 is a diagram showing a modification of the semiconductor light emitting device of FIG. FIG. 11 is a diagram showing a modification of the semiconductor light emitting device of FIG. 12 is a diagram for explaining one form of the mounting substrate in FIG. 4. FIG. FIG. 13 is a diagram showing a modification of the mounting substrate of FIG. 12. FIG. FIG. 14 is a diagram showing a modification of the mounting substrate of FIG. 12. FIG. 15 is a diagram showing a modification of the mounting substrate of FIG. 12. FIG. 16 is a diagram showing a modification of the mounting substrate of FIG. 12. FIG. 17 is a diagram showing a modification of the mounting substrate of FIG. 12. FIG. 18 is a diagram showing a modification of the mounting substrate of FIG. 12. FIG. FIG. 19 is a schematic plan view of a semiconductor light emitting device according to another embodiment of the invention. 20 is a cross-sectional view showing the XX-XX section of FIG. 19. FIG. 21 is a diagram showing a modification of the semiconductor light emitting device of FIG. 19. FIG. 22 is a diagram showing a modification of the semiconductor light emitting device of FIG. 19. FIG. 23 is a diagram showing a modification of the semiconductor light emitting device of FIG. 19. FIG.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic plan view of a semiconductor light emitting device 1 according to one embodiment of the invention. FIG. 2 is a sectional view showing a II-II section of FIG. 1 and 2 schematically show the semiconductor light emitting device 1, and the size ratios of the constituent elements do not necessarily match the actual ones.

A semiconductor light emitting device 1 is a light emitting device made up of a chip size package (CSP), and includes a substrate 2, an n-type nitride semiconductor layer 3, a light emitting layer 4, a p-type nitride semiconductor layer 5, an n It includes a side electrode 6 , a p-side electrode 7 and a mirror layer 8 . The n-type nitride semiconductor layer 3 , the light-emitting layer 4 and the p-type nitride semiconductor layer 5 constitute a nitride semiconductor multilayer structure 9 .
The substrate 2 is made of, for example, a translucent material (for example, sapphire, GaN, SiC, etc.) that transmits light having an emission wavelength λ (for example, 420 nm to 570 nm) of the light emitting layer 4, and is formed in a rectangular shape in plan view. . The thickness of the substrate 2 is, for example, 40 μm to 600 μm. In the substrate 2, the upper surface in FIG. 2 is the surface 2A, and the lower surface in FIG. 2 is the back surface 2B. In this embodiment, the surface 2A side of the substrate 2, that is, the nitride semiconductor multilayer structure 9 side with respect to the substrate 2 serves as a light extraction surface from which light is extracted.

Nitride semiconductor multilayer structure 9 includes n-type nitride semiconductor layer 3 , light-emitting layer 4 and p-type nitride semiconductor layer 5 . The n-type nitride semiconductor layer 3 is arranged on the substrate 2 side with respect to the light-emitting layer 4 , and the p-type nitride semiconductor layer 5 is arranged on the opposite side of the n-type nitride semiconductor layer 3 with respect to the light-emitting layer 4 . ing. Thus, the light emitting layer 4 is sandwiched between the n-type nitride semiconductor layer 3 and the p-type nitride semiconductor layer 5 to form a double heterojunction. Electrons are injected into the light emitting layer 4 from the n-type nitride semiconductor layer 3 and holes are injected from the p-type nitride semiconductor layer 5 . Light is generated by recombination of these in the light emitting layer 4 .

Further, similarly to the substrate 2, the nitride semiconductor multilayer structure 9 is formed in a rectangular shape in plan view, and includes a first short end surface 9A and a second short end surface 9B along a pair of short sides facing each other, and a pair of short sides facing each other. It has a first long end face 9C and a second long end face 9D along a pair of long sides. In addition, the nitride semiconductor multilayer structure 9 has a first corner 9E and a second corner 9F that are diagonal to each other, and a third corner 9G and a fourth corner 9H that are diagonal to each other. there is A first corner 9E and a third corner 9G are arranged at each end of the first short end face 9A, and a second corner 9F and a fourth corner 9H are arranged at each end of the second short end face 9B. It is

In this embodiment, the nitride semiconductor multilayer structure 9 is formed on the substrate 2 by so-called epitaxial growth (for example, vapor phase epitaxial growth (VPE), liquid phase epitaxial growth (LPE), solid phase epitaxial growth (SPE)). : Solid Phase Epitaxy), molecular beam epitaxial growth (MBE: Molecular Beam Epitaxy), etc.) by stacking an n-type nitride semiconductor layer 3, a light emitting layer 4 and a p-type nitride semiconductor layer 5 in this order. there is

The n-type nitride semiconductor layer 3 is laminated on the substrate 2 . In this embodiment, the n-type nitride semiconductor layer 3 is made of a group III-V nitride semiconductor transparent to the emission wavelength λ of the light emitting layer 4 . The thickness of n-type nitride semiconductor layer 3 may be, for example, 1.5 μm to 15 μm.
More specifically, n-type nitride semiconductor layer 3 may include an n-type GaN contact layer. The n-type GaN contact layer is composed of an n-type GaN layer doped with silicon as an n-type impurity, for example. The n-type impurity concentration of the n-type GaN contact layer may be, for example, approximately 1×10 ¹⁸ cm ⁻³ . The thickness of the n-type GaN contact layer may be, for example, 1.5 μm to 15 μm. An undoped GaN layer (for example, 1.5 μm to 10 μm thick) may be interposed between the n-type GaN contact layer and the substrate 2 .

The light emitting layer 4 has an MQW (multiple-quantum well) structure (multiple quantum well structure) containing, for example, InGaP, and emits light by recombination of electrons and holes. This layer is for amplification. The thickness of the light emitting layer 4 may be, for example, 7 nm to 150 nm.
More specifically, the light-emitting layer 4 is a multiple quantum well layer (for example, 2 nm thick) made of InGaN and a barrier layer (for example, 8 nm thick) made of AlInGaN alternately and repeatedly stacked for a plurality of cycles. It may have a well (MQW: Multiple-Quantum Well) structure.

A p-type nitride semiconductor layer 5 is formed on the light emitting layer 4 . The p-type nitride semiconductor layer 5 is made of a group III-V nitride semiconductor transparent to the emission wavelength λ of the light emitting layer 4 in this embodiment. The thickness of p-type nitride semiconductor layer 5 may be, for example, 0.05 μm to 0.3 μm.
More specifically, the p-type nitride semiconductor layer 5 includes a p-type AlGaN electron blocking layer formed on the light emitting layer 4 and a p-type GaN contact layer formed on the p-type AlGaN electron blocking layer. You can stay.

The p-type AlGaN electron blocking layer is composed of a p-type AlGaN layer doped with magnesium as a p-type impurity, for example. The p-type impurity concentration of the p-type AlGaN electron blocking layer may be, for example, approximately 3×10 ¹⁹ cm ⁻³ . The thickness of the p-type AlGaN electron blocking layer may be, for example, 1.5 nm to 30 nm.
The p-type GaN contact layer is composed of a p-type GaN layer doped with magnesium as a p-type impurity, for example. The p-type GaN contact layer may have a p-type impurity concentration higher than that of the p-type AlGaN electron blocking layer. The p-type impurity concentration of the p-type GaN contact layer may be, for example, approximately 1×10 ²⁰ cm ⁻³ . The thickness of the p-type GaN contact layer may be, for example, 10 nm to 100 nm.

A portion of the nitride semiconductor multilayer structure 9 is removed to form a mesa structure portion 10 .
More specifically, from the surface of nitride semiconductor multilayer structure 9 , p-type nitride semiconductor layer 5 , light emitting layer 4 , and part of n-type nitride semiconductor layer 3 extend over the entire periphery of nitride semiconductor multilayer structure 9 . A mesa structure portion 10 having a wall surface 11 extending from the p-type nitride semiconductor layer 5 to the n-type nitride semiconductor layer 3 via the light emitting layer 4 is formed by etching away. A low stepped portion 12 having an upper surface 12A exposing the n-type nitride semiconductor layer 3 is formed around the mesa structure 10 so as to surround the entire periphery of the mesa structure 10 . As a result, wall surface 11 of mesa structure 10 is arranged at a position recessed inwardly with respect to short end surfaces 9A, 9B and long end surfaces 9C, 9D of nitride semiconductor multilayer structure 9 over the entire circumference.

In this embodiment, the mesa structure 10 is biased toward the second short facet 9B so that the electrode region 13 for the n-side electrode 6 is provided between the mesa structure 10 and the first short facet 9A of the nitride semiconductor multilayer structure 9. formed. In other words, in the nitride semiconductor multilayer structure 9, a lead portion is formed by selectively leading a portion of the n-type nitride semiconductor layer 3 from the mesa structure portion 10 toward the first short end surface 9A. An upper surface 12A of the lead portion constitutes an electrode region 13. As shown in FIG. Therefore, regarding the distance between the wall surface 11 of the mesa structure portion 10 and the short end surfaces 9A, 9B and the long end surfaces 9C, 9D of the nitride semiconductor multilayer structure 9, the distance between the wall surface 11 and the short end surface 9A is equal to the wall surface 11 and the short end surface. It is relatively longer than the distance to 9B and long end faces 9C and 9D. The distances between the wall surface 11 and the short end surface 9B and the long end surfaces 9C and 9D may be substantially the same as shown in FIG.

Further, in this embodiment, the mesa structure portion 10 is formed to have a substantially quadrangular cross-sectional shape as shown in FIG. . In addition, the mesa structure portion 10 is formed in a substantially quadrangular shape in plan view.
One n-side electrode 6 is arranged in the electrode region 13 with a gap from each end face 9A, 9C, 9D of the nitride semiconductor multilayer structure 9 . The n-side electrode 6 is formed in a rectangular shape along the first short end face 9A in this embodiment. Since the electrode region 13 is formed at the end of the nitride semiconductor multilayer structure 9 on one side in the long side (the first short end face 9A side), the upper surface space of the nitride semiconductor multilayer structure 9 is n The side electrode 6 is arranged at the end on the side of the first short end face 9A.

Also, the n-side electrode 6 is made of Au or an alloy containing Au in this embodiment. For example, the n-side electrode 6 may have a laminated structure represented by Ti/Au, Cr/Au, Cr/Pt/Au, and TiN/Al/Au (on the substrate 2 side).
Further, the n-side electrode 6 is a protruding portion that protrudes above the upper surface 10A so as to have the upper surface 6A at the same height position as the upper surface 7A of the p-side electrode 7 with respect to the upper surface 10A of the mesa structure portion 10. 14. By aligning the top surface 7A of the p-side electrode 7 with the top surface 6A of the n-side electrode, it is possible to prevent the semiconductor light emitting element 1 from tilting when the semiconductor light emitting element 1 is flip-chip bonded. For example, the thickness of the n-side electrode 6 is 1 μm to 20 μm.

One p-side electrode 7 is arranged on the upper surface 10A of the mesa structure 10 near the second short end face 9B with a gap from the wall surface 11 of the mesa structure 10 . In this embodiment, the p-side electrode 7 is formed in a rectangular shape along the second short end face 9B, and may be line-symmetrical with the n-side electrode 6, for example.
More specifically, the p-side electrode 7 is located on the opposite side of the n-side electrode 6 in the direction along the long side of the nitride semiconductor multilayer structure 9 with respect to the upper surface space of the nitride semiconductor multilayer structure 9 (the side of the second short end face 9B). ) is formed at the end of the Thus, the upper surface 10A of the mesa structure portion 10 has a length L1 that is substantially the same as the length in the direction along the short side of the nitride semiconductor multilayer structure 9 and a length L2 (width) that is greater than the length L1. A light extraction region 15 is formed. The light extraction region 15 is a region in which an electrode film such as the p-side electrode 7 is not formed, and is composed of an exposed region of the p-type nitride semiconductor layer 5 on the upper surface 10A of the mesa structure portion 10 .

Also, the p-side electrode 7 is made of Au or an alloy containing Au in this embodiment. For example, the p-side electrode 7 may have a laminated structure represented by Ti/Au, Cr/Au, Cr/Pt/Au, and TiN/Al/Au (on the substrate 2 side). Moreover, the thickness of the p-side electrode 7 is, for example, 1 μm to 20 μm.
Mirror layer 8 is formed on rear surface 2B of substrate 2 . The mirror layer 8 must face at least the light extraction region 15, and is formed over the entire rear surface 2B of the substrate 2 in this embodiment. Thereby, the light from the light emitting layer 4 can be reflected and efficiently guided to the light extraction region 15 . The mirror layer 8 is composed of an alloy containing Ag or Al in this embodiment. Also, the thickness of the mirror layer 8 is, for example, 10 nm to 200 nm.

FIG. 3 is a schematic perspective view of a light emitting device 16 (wristband) according to one embodiment of the invention. FIG. 4 is a diagram schematically showing the internal structure of the light emitting device 16 of FIG. FIG. 5 is a reference diagram for comparison with the internal structure of FIG.
The light emitting device 16 is a wearable device that can be attached to the body and carried around, and is configured as a wristband in this embodiment. A light-emitting device 16 as a wristband includes a ring-shaped band 17, a display 18 formed on one surface 17A of the band 17, and a light-emitting portion 19 formed on one surface 17A of the band.

As shown in FIG. 4, the band 17 is configured by, for example, overlapping flexible plate-like members 20 and 21 (made of resin, for example). A cavity 22 is formed between the
The display 18 and the light emitting section 19 are formed on the surface 17A on the member 20 side. The display 18 can display various types of information. For example, the user's action record, health record, etc. may be displayed by processing them with a semiconductor device 25, which will be described later. The light emitting part 19 may be a part that blinks, lights up, or goes out in order to notify the user of some information. An opening 23 is formed in a portion corresponding to the light emitting portion 19 on one surface 17A of the band 17 .

As shown in FIG. 3 , a mounting board 24 is provided in the cavity 22 of the band 17 . The mounting board 24 has one surface 24A and the other surface 24B, and the semiconductor light emitting element 1 and other semiconductor elements 25 are bonded to lands 28 on the one surface 24A. Semiconductor element 25 may be, for example, an IC, a switching element, a sensor element, a passive element, or the like. The semiconductor light emitting element 1 and the semiconductor element 25 are flip-chip bonded to lands 28 on one surface 24A of the mounting substrate 24, respectively. Taking the semiconductor light emitting device 1 as an example, it is bonded to the mounting substrate 24 so that the light extraction region 15 faces one surface 24A of the mounting substrate 24 . An opening 26 , which is an example of the light transmitting portion of the present invention, is selectively formed in the mounting substrate 24 at a position facing the light extraction region 15 .

According to the above configuration, in the semiconductor light emitting device 1, the mirror layer 8 is formed on the back surface 2B of the substrate 2 as shown in FIG. It can be taken out from the side of the nitride semiconductor multilayer structure 9 by separating the two. Moreover, since the light extraction region 15 is provided between the n-side electrode 6 and the p-side electrode 7 so that the p-side electrode 7 and the n-side electrode 6 do not obstruct light as much as possible, the light is relatively sufficient. high light extraction efficiency.

As a result, in the light emitting device 16 shown in FIG. 4, when the semiconductor light emitting element 1 is flip-chip bonded to the mounting substrate 24, light is extracted to the bonding surface (surface 24A facing the semiconductor light emitting element 1) of the mounting substrate 24. , through the openings 23 and 26 . Therefore, as shown in FIG. 4, even when it is desired to extract light to the other surface 24B on the side opposite to the die-bonding surface of the mounting substrate 24, the semiconductor light emitting device 1 is mounted on the mounting substrate in the same manner as the other semiconductor device 25. 24 can be arranged on one side 24A.

That is, as shown in FIG. 5, in the semiconductor light emitting device 27 having the mirror layer 30 on the front surface side of the substrate and extracting light from the back surface 2B side of the substrate, the light extraction surface is the back surface 2B of the substrate. , the semiconductor light emitting element 27 must be bonded to the land 29 on the other surface 24B of the mounting board 24, and the other semiconductor element 25 cannot be mounted on the same bonding surface. As a result, a structure in which the elements are bonded to both surfaces 24A and 24B of the mounting substrate 24 is obtained, and the mountability of the light emitting device is greatly deteriorated. For example, a wide cavity 22 is required for the mounting substrate 24, as is apparent from a comparison of FIGS. Further, when the mounting board 24 is fixed to the member 20, the semiconductor light emitting element 27 becomes an obstacle, and when the mounting board 24 is fixed to the member 21, the semiconductor element 25 becomes an obstacle.

On the other hand, if the semiconductor light emitting device 1 is used, the cavity 22 can be made small (thin), and if the other surface 24B on the side opposite to the bonding surface of the mounting substrate 24 is used as a fixing surface to the band 17, mounting is possible. Substrate 24 can also be simply fixed to band 17 . Therefore, the light emitting device 16 can be miniaturized and the structure can be simplified.
6 to 11 are diagrams showing modifications of the semiconductor light emitting device 1, mainly showing modifications of the arrangement and shape of the n-side electrode 6 and the p-side electrode 7 and the shape of the electrode region 13. FIG.

In the structure shown in FIGS. 1 and 2, each of the n-side electrode 6 and the p-side electrode 7 has a rectangular shape along the first short end surface 9A and the second short end surface 9B of the nitride semiconductor multilayer structure 9, and is arranged one by one. was formed.
On the other hand, as shown in FIG. 6, two n-side electrodes 6 are formed, one each at the corners 9E and 9G of the nitride semiconductor multilayer structure 9 at both ends of the first short end face 9A. good too. Similarly, two p-side electrodes 7 may be formed, one at each of the corners 9F and 9H of the nitride semiconductor multilayer structure 9 at both ends of the second short end face 9B.

Further, as shown in FIG. 7, a plurality of (five each in FIG. 7) n-side electrodes 6 and p-side electrodes 7 are formed by first short end surfaces 9A and second short end surfaces 9B of the nitride semiconductor multilayer structure 9, respectively. may be arranged along
Further, the n-side electrode 6 and the p-side electrode 7 do not have to be rectangular in plan view as described above, and may be circular in plan view, for example.

For example, as shown in FIG. 8, the n-side electrode 6 and the p-side electrode 7 are elliptical in shape extending along the first short end surface 9A and the second short end surface 9B of the nitride semiconductor multilayer structure 9, respectively. They may be formed one by one.
Also, as shown in FIG. 9, the n-side electrode 6 is circular, and two in total are formed, one at each of the corners 9E and 9G of the nitride semiconductor multilayer structure 9 at both ends of the first short end face 9A. may be Similarly, the p-side electrode 7 may also be circular, and two electrodes may be formed, one at each of the corners 9F and 9H of the nitride semiconductor multilayer structure 9 at both ends of the second short end face 9B.

Further, as shown in FIG. 10, a plurality (five each in FIG. 7) of circular n-side electrodes 6 and p-side electrodes 7 are formed on the first short end surface 9A and the second short end surface 9A of the nitride semiconductor multilayer structure 9, respectively. They may be arranged along the end surface 9B.
1 and 2, the electrode region 13 having a constant width from the first short end face 9A of the nitride semiconductor multilayer structure 9 extends in the direction along the first short end face 9A (short direction of the nitride semiconductor multilayer structure 9). direction along the side).

On the other hand, as shown in FIG. 11, the electrode region 13 may be selectively formed only at one corner of the nitride semiconductor multilayer structure 9 (first corner 9E in FIG. 11). In this case, the wall surface 11 of the mesa structure 10 facing the electrode region 13 may be curved as shown in FIG.
Next, with reference to FIGS. 12 to 18, multiple forms of the mounting substrate 24 provided inside the light emitting device 16 of FIG. 4 will be described.

First, as described above, when the opening 26 is formed in the mounting substrate 24 at a position facing the light extraction region 15, as shown in FIG. may be composed of This is because light can be extracted through the opening 26 even if the mounting substrate 24 is opaque. Usable colored material substrates include, for example, glass epoxy substrates, silicon substrates, and acrylic substrates.

On the other hand, the mounting board 24 may be made of a transparent material, as shown in FIG. In this case, since light can pass through the main body of the mounting substrate 24, the opening 26 is not formed, and the portion of the mounting substrate 24 facing the light extraction region 15 (the facing portion 31) is configured as an example of the light transmitting portion of the present invention. may be Usable transparent material substrates include, for example, epoxy substrates, sapphire substrates, glass substrates, PET substrates, acrylic substrates, and the like. Also, the transparent material substrate may contain a phosphor. If the entire mounting board 24 is light transmissive, light from the semiconductor light emitting element 1 can be reliably extracted even if the semiconductor light emitting element 1 is bonded to the mounting board 24 while being displaced.

Also, as shown in FIGS. 14 and 15, a sealing resin 32 made of, for example, a transparent material may be formed on the one surface 24A side of the mounting substrate 24. As shown in FIGS. The sealing resin 32 seals the semiconductor light emitting element 1 and the semiconductor element 25 (illustration is omitted in FIGS. 14 and 15).
Further, as shown in FIG. 16 , when a colored material substrate is used as the mounting substrate 24 , the mounting substrate 24 may further have a convex lens 33 formed to cover the opening 26 . The lens 33 can condense the extracted light. Also, the lens 33 may protrude outside the member 20 through the opening 23 of the light emitting device 16 .

Similarly, as shown in FIG. 17, when a transparent material substrate is used as the mounting substrate 24, the mounting substrate 24 further has a convex lens portion 34 integrally formed with the facing portion 31. good too. The extracted light can be condensed by the lens portion 34 . Also, the lens portion 34 may protrude outside the member 20 through the opening 23 of the light emitting device 16 .

Further, as shown in FIG. 18, the sealing resin 32 on the mounting substrate 24 may be made of colored resin. Usable colored resins include, for example, epoxies, acrylics, silicones, and the like.
FIG. 19 is a schematic plan view of a semiconductor light emitting device 41 according to another embodiment of the invention.
20 is a cross-sectional view showing the XX-XX section of FIG. 19. FIG. In the following, configurations different from those of the semiconductor light emitting device 1 shown in FIGS. 1 and 2 will be mainly described, and common configurations will be given the same reference numerals and descriptions thereof will be omitted.

As shown in FIGS. 19 and 20, in the semiconductor light emitting device 41, the mesa structure portion 42 is arranged so that the electrode region 13 for the n-side electrode 6 is provided between the first short facet 9A of the nitride semiconductor multilayer structure 9 and the first short facet 9A. and the second electrode region 43 for the p-side electrode 7 is formed in the substantially central portion in the direction along the long side of the nitride semiconductor multilayer structure 9 so that the second electrode region 43 for the p-side electrode 7 is provided between the second short end face 9B and the second short end face 9B. . That is, in the direction along the long side of the nitride semiconductor multilayer structure 9, on both sides of the mesa structure portion 42, the electrode regions 13 and 43 having a constant width from the short end faces 9A and 9B are formed along the short end faces 9A and 9B. formed. In this embodiment, the electrode regions 13 and the second electrode regions 43 have the same width as each other.

The mesa structure portion 42 has a wall surface 44 extending from the p-type nitride semiconductor layer 5 to the n-type nitride semiconductor layer 3 through the light emitting layer 4 . This wall surface 44 is arranged at a position recessed inwardly with respect to the short end surfaces 9A, 9B and the long end surfaces 9C, 9D of the nitride semiconductor multilayer structure 9 over the entire circumference.
An insulating film 45 is formed to cover the upper surface 42A of the mesa structure 42, the wall surface 44, the electrode region 13 and the second electrode region 43. As shown in FIG. The insulating film 45 is made of an insulating material such as silicon oxide (SiO ₂ ), silicon nitride (SiN), or the like. An opening 46 is formed in the insulating film 45 to expose a part of the upper surface 42A (p-type nitride semiconductor layer 5) of the mesa structure 42. As shown in FIG. The opening 46 may be, for example, circular in plan view. Further, the insulating film 45 is formed with an opening 47 that exposes a part of the electrode region 13 (n-type nitride semiconductor layer 3).

A wiring film 48 is formed on the insulating film 45 . The wiring film 48 is connected to the p-type nitride semiconductor layer 5 through the opening 46 of the insulating film 45 , and extends over the second electrode region 43 from the opening 26 along the wall surface 44 on the side of the second electrode region 43 . extends to the area of This wiring film 48 is made of, for example, a transparent electrode film such as zinc oxide (ZnO) or indium tin oxide (ITO). By using a transparent electrode film, light can be extracted from the contact region of the transparent electrode film (in this embodiment, the opening 46 portion of the insulating film 45), so that a decrease in light extraction efficiency can be suppressed. can be done.

The n-side electrode 6 is connected to the n-type nitride semiconductor layer 3 through the opening 47 of the insulating film 45, and the p-side electrode 7 is connected to the wiring film 48 in the region above the second electrode region 43. ing. The p-side electrode 7 is electrically connected to the p-type nitride semiconductor layer 5 via the wiring film 48 .
According to this semiconductor light emitting device 41, at least the region above the opening 46 of the insulating film 45 is the wiring film 48 made of the transparent electrode film. Therefore, the opening 46 functions as an example of the light extraction region 15 of the present invention. Therefore, the light generated in the light emitting layer 4 can be extracted from the opening 46 of the insulating film 45 by reflecting it on the mirror layer 8 .

As a result, in the light emitting device 16 shown in FIG. 4, when the semiconductor light emitting element 41 is flip-chip bonded to the mounting board 24 in place of the semiconductor light emitting element 1, light is extracted to the bonding surface side of the mounting board 24, and the openings 23, 26 to the outside.
In addition, in the semiconductor light emitting device 41, the shape of the light extraction region 15 can be easily changed by changing the mask pattern used when forming the opening 46 in the insulating film 45. FIG. The shape of the opening 46 may be, for example, a square shape as shown in FIG. 21, a triangular shape as shown in FIG. 22, a star shape as shown in FIG. 23, or the like.

Although not shown, the patterns of the n-side electrode 6 and the p-side electrode 7 shown in FIGS. 6 to 11 can also be employed in the semiconductor light emitting device 41 as well.
Although the embodiments of the present invention have been described above, the present invention can also be implemented in other forms.
For example, wearable devices (light emitting devices) to which the semiconductor light emitting elements 1 and 41 are applied include the wristband shown in FIG. 3, micro LEDs, eyewear, contact lenses, and the like.

In addition, various design changes can be made within the scope of the matters described in the claims.

REFERENCE SIGNS LIST 1 semiconductor light-emitting element 2 substrate 2A front surface 2B rear surface 3 n-type nitride semiconductor layer 4 light-emitting layer 5 p-type nitride semiconductor layer 6 n-side electrode 7 p-side electrode 8 mirror layer 9 nitride semiconductor multilayer structure 9A first short facet 9B Second short end surface 10 Mesa structure portion 10A Upper surface 11 Wall surface 12 Low step portion 12A Upper surface 13 Electrode region 15 Light extraction region 16 Light emitting device 24 Mounting substrate 24A One surface 24B Other surface 25 Semiconductor element 26 Opening 31 Opposing portion 32 Sealing resin 33 Lens 34 Lens portion 41 Semiconductor light emitting element 42 Mesa structure portion 43 Second electrode region 44 Wall surface 45 Insulating film 46 Opening 48 Wiring film

Claims (10)

a translucent substrate;
The p a mesa structure portion having a wall surface extending from a type semiconductor layer to the n-type semiconductor layer through the light emitting layer; and a low step portion disposed around the mesa structure portion and having an upper surface exposing the n-type semiconductor layer. a semiconductor lamination structure comprising
a p-side electrode disposed on the surface side of the semiconductor multilayer structure and electrically connected to the p-type semiconductor layer;
an n-side electrically connected to the n-type semiconductor layer, disposed on the surface side of the semiconductor multilayer structure with a light extraction region for extracting light from the light-emitting layer between the p-side electrode and the p-side electrode; an electrode;
a mirror layer formed on the back surface of the substrate so as to face at least the light extraction region;
The mesa structure portion has a first electrode region for the n-side electrode between it and the first end face, and a second electrode region for the p-side electrode between it and the second end face. is formed in the central part of the semiconductor laminated structure so as to be empty,
the light extraction region includes an upper surface region of the mesa structure formed by the p-type semiconductor layer ;
an insulating film is formed to cover the upper surface of the mesa structure portion, the wall surface, and the upper surface of the second electrode region, the n-side electrode is arranged on the upper surface of the first electrode region;
The p-side electrode is arranged on the upper surface of the second electrode region via the insulating film,
the insulating film has an opening that exposes the upper surface region at a central portion of the upper surface of the mesa structure portion as the light extraction region and the contact region;
further comprising a wiring film formed on the insulating film and including a transparent electrode film that connects the p-side electrode and the p-type semiconductor layer exposed on the upper surface of the mesa structure ,
from a chip size package (CSP) , wherein the transparent electrode film is formed to cover the light extraction region and the contact region and is connected to the p-type semiconductor layer through the opening of the insulating film; A semiconductor light emitting device. 2. The n-side electrode and the p-side electrode according to claim 1, wherein one of said n-side electrode and said p-side electrode are respectively arranged at an end portion on said first end surface side and an end portion on said second end surface side of said semiconductor multilayer structure. Semiconductor light emitting device. 3. The semiconductor light emitting device according to claim 1, wherein said substrate includes a sapphire substrate. a mounting substrate having one surface and the other surface and including a light transmitting portion through which light can be transmitted from the one surface to the other surface;
and the semiconductor light emitting element according to any one of claims 1 to 3 flip-chip bonded to the one surface of the mounting substrate such that the light extraction region faces the light transmitting portion. . 5. The light emitting device according to claim 4 , further comprising another semiconductor element arranged on said one surface of said mounting substrate and having a function different from said semiconductor light emitting element. The mounting substrate is made of an opaque plate material,
The light-emitting device according to claim 4 or 5 , wherein the light transmission portion includes an opening penetrating through the opaque plate. 7. The light emitting device according to claim 6 , further comprising a convex lens formed on said other surface of said mounting substrate so as to cover said opening. The mounting substrate is made of a transparent plate material,
6. The light - emitting device according to claim 4 , wherein said light transmitting portion includes a portion of said transparent plate facing said light extraction region. 9. The light-emitting device according to claim 8 , wherein said mounting substrate has a convex lens portion integrally formed with said light transmitting portion on said other surface. 10. The light-emitting device according to claim 4 , further comprising a sealing resin formed on said one surface side of said mounting substrate so as to cover said semiconductor light-emitting element.

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