JP6635206B1 - Light emitting element and light emitting device - Google Patents

Abstract

A light-emitting element with improved reliability is provided. A light emitting device is a semiconductor structure including a first semiconductor layer having a first region and a second region, and a second semiconductor layer above the second region, wherein the first region is A semiconductor structure including an extension portion Ep each extending from the outer peripheral portion Pp to the second region, a first through hole 141 located in each extension portion, and a second through hole 142 located in the second region. A first insulating layer 140, a second insulating layer 160 having a third through hole 163 and a fourth through hole 164, and a first insulating layer connected to the first semiconductor layer via the first and third through holes. An external electrode 170An and a second external electrode 170Ap connected to the second semiconductor layer via the second through hole and the fourth through hole are provided, and each extension portion is a first of the upper surfaces of the first semiconductor layer. Places other than those overlapping the corners of the external electrode Beauty is disposed at a position other than the position overlapping with the corner portion of the second external electrode. [Selection diagram] FIG.

Description

  The present disclosure relates to a light emitting element and a light emitting device.

  2. Description of the Related Art A light emitting device having a rectangular light emitting surface from which light is extracted is known. Such a light-emitting device includes, for example, a light-emitting element having a rectangular outer shape in a top view, and typically has a rectangular parallelepiped appearance as a whole. A light emitting device having a rectangular parallelepiped appearance is used for a backlight unit of a liquid crystal display device, for example, in combination with a light guide plate. Patent Literature 1 below discloses a group III nitride semiconductor light emitting device having a structure in which an n-type semiconductor layer and a p-type semiconductor layer are stacked on a rectangular sapphire substrate.

JP-A-2006-143682

  The present disclosure provides a light emitting device with improved reliability.

  A light-emitting device according to an embodiment of the present disclosure includes a first semiconductor layer of a first conductivity type having a first region and a second region located inside the first region, an active layer located on the second region, and A semiconductor structure including a second conductivity-type second semiconductor layer located on the active layer, wherein the first region has an outer peripheral portion located on an outer periphery of the second region in a top view, A semiconductor structure including a plurality of extensions extending from the outer periphery to the second region, a light-reflective electrode covering an upper surface of the second semiconductor layer, and covering the semiconductor structure and the light-reflective electrode A first insulating layer having a first through-hole located at each extension of the first region and a second through-hole located at the second region, the first insulating layer being located on the first insulating layer, A first internal electrode electrically connected to the first semiconductor layer through a through hole; And a second internal electrode located on the first insulating layer and electrically connected to the light-reflective electrode through the second through hole, and the first internal electrode and the second internal electrode. A second insulating layer that covers and electrically insulates the first internal electrode and the second internal electrode from each other, the third insulating layer being located on the first internal electrode, and being located on the second internal electrode. A second insulating layer having a fourth through-hole, a first external electrode having a plurality of corners electrically connected to the first internal electrode through the third through-hole, and the fourth through-hole. And a second external electrode having a plurality of corners electrically connected to the second internal electrode through the first region. Each of the plurality of extending portions of the first region is configured such that Items other than positions overlapping the plurality of corners of the first external electrode on the upper surface of the semiconductor layer. And it is disposed at a position other than the position overlapping with the plurality of corner portions of the second outer electrode.

  According to the embodiments of the present disclosure, a light-emitting element with improved reliability is provided.

1 is a perspective view illustrating an example of an appearance of a light emitting device according to an embodiment of the present disclosure. FIG. 2 is a schematic sectional view showing a II-II section of FIG. 1. FIG. 1 is a schematic perspective view of a light emitting device according to an embodiment of the present disclosure as viewed from a lower surface side. FIG. 4 is a schematic sectional view showing an IV-IV section in FIG. 3. FIG. 5 is a schematic sectional view showing a VV section of FIG. 3. FIG. 9 is a schematic plan view for explaining an arrangement relationship between a p-type semiconductor layer 120p and an n-type semiconductor layer 120n. FIG. 4 is a schematic plan view showing a state where a first insulating layer 140 is formed on a light reflective electrode 130. FIG. 4 is a schematic plan view showing a state where a first internal electrode 150n and a second internal electrode 150p are formed on a first insulating layer 140. FIG. 9 is a schematic plan view showing a state where a second insulating layer 160 is further formed on a first internal electrode 150n and a second internal electrode 150p. FIG. 9 is a plan view schematically showing a semiconductor structure 112A of a light emitting element 100A, and first and second external electrodes 170An and 170Ap. FIG. 4 is a perspective view illustrating another example of the appearance of the light emitting device according to an embodiment of the present disclosure. FIG. 12 is a schematic cross-sectional view showing a XII-XII cross section of FIG. 11. FIG. 9 is a schematic perspective view illustrating, as a comparative example, a light emitting element in which a plurality of extending portions and a plurality of through holes provided in an insulating layer are arranged at positions overlapping corner portions of an external electrode. FIG. 14 is a schematic cross-sectional view showing a XIV-XIV cross section of FIG. 13. FIG. 9 is a diagram for explaining an example of a relationship between shapes of a first external electrode 170An and a second external electrode 170Ap and arrangement of a plurality of extending portions Ep. FIG. 11 is a schematic perspective view illustrating another example of the light emitting device according to the embodiment of the present disclosure. FIG. 17 is a schematic plan view showing a semiconductor structure in the light emitting element 100B shown in FIG. 16 and a first external electrode 170Bn and a second external electrode 170Bp. FIG. 11 is a schematic perspective view illustrating still another example of the light emitting device according to the embodiment of the present disclosure. FIG. 9 is a diagram illustrating a calculation result of an absolute value of a shear stress regarding the sample of Reference Example 1. FIG. 9 is a diagram illustrating a calculation result of an absolute value of a shear stress regarding the sample of Reference Example 2. FIG. 14 is a diagram illustrating a calculation result of an absolute value of a shear stress regarding the sample of Reference Example 3. FIG. 14 is a view showing a calculation result of an absolute value of a shear stress regarding the sample of Reference Example 4.

  Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following embodiment is an exemplification, and the light emitting device according to the present disclosure is not limited to the following embodiment. For example, the numerical values, shapes, materials, steps, the order of the steps, and the like shown in the following embodiments are merely examples, and various modifications are possible as long as there is no technical inconsistency.

  The dimensions, shapes, and the like of components illustrated in the drawings may be exaggerated for simplicity, and may not reflect the dimensions, shapes, and magnitude relationships between components in an actual light emitting device. In some cases, some components are not illustrated in order to avoid excessively complicated drawings.

  In the following description, components having substantially the same function are denoted by common reference numerals, and description thereof may be omitted. In the following description, terms indicating a specific direction or position (eg, “up,” “down,” “right,” “left,” and other terms that include those terms) may be used. However, these terms are only used for clarity in relative directions or positions in the referenced drawings. If the relative directions or positional relations by the terms such as “up” and “down” in the referenced drawings are the same, in drawings other than the present disclosure, actual products, manufacturing apparatuses, etc., the same as the referenced drawings It does not have to be an arrangement. In this disclosure, “parallel” includes a case where two straight lines, sides, surfaces, and the like are in a range of about 0 ° to about ± 5 °, unless otherwise specified. Further, in the present disclosure, “vertical” or “perpendicular” includes a case where two straight lines, sides, surfaces, and the like are in a range of about 90 ° to about ± 5 °, unless otherwise specified.

(Embodiment of light emitting element and light emitting device)
FIG. 1 shows an example of the appearance of a light emitting device according to an embodiment of the present disclosure, and FIG. 2 schematically shows a cross section taken along line II-II of FIG. For reference, FIGS. 1 and 2 show an X axis, a Y axis, and a Z axis orthogonal to each other. In other drawings of the present disclosure, the X axis, the Y axis, and the Z axis may be shown.

  The light-emitting device 300 illustrated in FIGS. 1 and 2 schematically includes a light-emitting element 100 including a light-transmitting first substrate and a semiconductor structure on the first substrate, and a second substrate supporting the light-emitting element 100. And a support 200. In the configuration illustrated in FIG. 1, the light emitting element 100 is covered with a light reflective member 190. Light from the light emitting element 100 is emitted in a substantially Z direction in the drawing via a light transmitting member 182 disposed on the front surface of the light emitting element 100.

  As shown in FIGS. 1 and 2, the support 200 includes an insulating base 230 and a first wiring 210 and a second wiring 220 on the base 230. As shown in FIG. 2, the light emitting element 100 schematically includes a light emitting structure 110 including the first substrate and the semiconductor structure described above as a part thereof, and a first light emitting structure 110 for supplying a current to the light emitting structure 110. It has an external electrode 170An and a second external electrode 170Ap. As schematically shown in FIG. 2, the first wiring 210 and the second wiring 220 of the support 200 are provided so as to cover the upper surface 230 a to the lower surface 230 b of the base 230. The first wiring 210 is connected to the first external electrode 170An of the light emitting element 100, and the second wiring 220 is connected to the second external electrode 170Ap. The first wiring 210 and the second wiring 220 are electrically and physically connected to the light emitting structure 110 of the light emitting device 100 via the first external electrode 170An and the second external electrode 170Ap, respectively. The details of the light emitting structure 110 will be described later.

  In the configuration illustrated in FIG. 2, the light emitting device 300 has a wavelength conversion member 180 and a light transmitting member 182 above the light emitting element 100. The wavelength conversion member 180 is, for example, a plate-like member in which particles of a YAG-based phosphor or the like are dispersed in silicone resin, and the light-transmitting member 182 is, for example, a plate-like member mainly formed of silicone resin. It is. The light guide member 174 is disposed between the wavelength conversion member 180 and the light emitting element 100. The light guide member 174 is a translucent member formed of, for example, a silicone resin. As shown, a part of the light guide member 174 covers the side surface 110c of the light emitting structure 110. The above-described light-reflective member 190 surrounds the structure on the support 200, and the upper surface 182 a of the light-transmitting member 182 is exposed from the light-reflective member 190 as schematically shown in FIG. 2. The upper surface 182a of the light transmitting member 182 forms a part of the upper surface 300a of the light emitting device 300. The light reflective member 190 is, for example, a member having a resin material containing a silicone resin as a base material and light scattering fillers dispersed therein.

  Hereinafter, the details of the light emitting device 100 will be described with reference to the drawings. FIG. 3 is a schematic perspective view of the light emitting device according to the embodiment of the present disclosure as viewed from the lower surface side, and FIGS. 4 and 5 schematically show the IV-IV cross section and the VV cross section of FIG. 3, respectively. Shown in

  The light-emitting element 100A shown in FIGS. 3 to 5 is an example of the light-emitting element 100 described with reference to FIGS. In the configuration illustrated in FIGS. 3 to 5, the light emitting element 100 </ b> A has a rectangular shape longer in the Y direction than in the X direction when viewed from above. The length of the light emitting element 100A in the X direction is, for example, about 100 μm to 300 μm. The length of the light emitting element 100A in the Y direction is, for example, about 700 μm to 1400 μm, and preferably about 900 μm to 1200 μm.

As shown in FIGS. 4 and 5, the light emitting structure 110A of the light emitting element 100A includes a light transmitting first substrate 111 and a semiconductor structure 112A supported by the first substrate 111. Typical examples of the first substrate 111 is a sapphire substrate, the semiconductor structure 112A is typically capable of light emission by a nitride semiconductor of the ultraviolet to visible range _{(In x Al y Ga 1-} xy N, 0 ≦ x , 0 ≦ y, x + y ≦ 1).

  The semiconductor structure 112A includes an n-type semiconductor layer 120n as a first semiconductor layer having a first conductivity type, a p-type semiconductor layer 120p as a second semiconductor layer having a second conductivity type, and n-type semiconductor layers 120n and p. The active layer 120a is located between the active layer 120a and the semiconductor layer 120p. The light emitting structure 110A of the light emitting device 100A includes a plurality of insulating layers and a plurality of electrodes in addition to the semiconductor structure 112A. As shown in FIGS. 4 and 5, the light emitting structure 110A includes a first insulating layer 140, a second insulating layer 160, a light reflective electrode 130 located between the p-type semiconductor layer 120p and the first insulating layer 140, It includes a first internal electrode 150n and a second internal electrode 150p.

  In the semiconductor structure 112A, the n-type semiconductor layer 120n is located on the first substrate 111 and covers substantially the entire upper surface 111a of the first substrate 111. As shown in FIG. 3, the n-type semiconductor layer 120n has a first region R1 and a second region R2 located inside the first region R1. In other words, the upper surface of the n-type semiconductor layer 120n includes the first region R1 and the second region R2 located inside the first region R1. The active layer 120a is selectively formed on the second region R2 of the n-type semiconductor layer 120n. The p-type semiconductor layer 120p located on the active layer 120a is also located almost directly above the second region R2. In other words, a portion of the n-type semiconductor layer 120n located in the first region R1 is not covered with the active layer 120a and the p-type semiconductor layer 120p, and is exposed from these layers.

  FIG. 6 shows an arrangement relationship between the p-type semiconductor layer 120p and the n-type semiconductor layer 120n. FIG. 6 corresponds to a diagram showing the n-type semiconductor layer 120n, the active layer 120a, and the p-type semiconductor layer 120p extracted from the light emitting structure 110A. As described above, the active layer 120a and the p-type semiconductor layer 120p cover the second region R2 of the n-type semiconductor layer 120n. Although not explicitly shown in FIG. 6, the active layer 120a may be considered to occupy almost the same region as the p-type semiconductor layer 120p.

  As shown in FIG. 6, the first region R1 of the n-type semiconductor layer 120n includes an outer peripheral portion Pp located outside the second region R2 in a top view, and a plurality of extending portions Ep. In FIG. 6, for the sake of simplicity, a portion corresponding to the extension portion Ep in the first region R1 is shown by hatching. As shown in the drawing, each of the plurality of extending portions Ep is a portion of the first region R1 extending from the outer peripheral portion Pp to the second region R2. From another viewpoint, the second region R2 has an upper surface. It can be said that it has a plurality of concave portions when viewed, and the extended portion Ep is formed at a position corresponding to these concave portions in the first region R1. In addition, it can be said that the active layer 120a and the p-type semiconductor layer 120p have a plurality of concave portions at positions corresponding to the respective extending portions Ep of the first region R1 in a top view.

  In this example, the n-type semiconductor layer 120n has a rectangular outer shape including a first long side LS1 and a second long side LS2 facing each other when viewed from above, and the second long side is longer than the first long side LS1. Four extension parts Ep1 to Ep4 are provided near LS2. Here, the first long side LS1 and the second long side LS2 are parallel to the Y direction.

  The semiconductor structure 112A can be obtained by applying a known semiconductor process. For example, the n-type semiconductor layer 120n, the active layer 120a, and the p-type semiconductor layer 120p are formed on the upper surface of the first substrate 111 by metal organic chemical vapor deposition (MOCVD, MOVPE), hydride vapor deposition (HVPE), or the like. After the nitride semiconductor layer is formed on 111a, the active layer and the p-type semiconductor layer can be formed by removing a portion located on first region R1 by photolithography and etching.

  Please refer to FIG. 4 and FIG. The light reflective electrode 130 covers the upper surface 120pa of the p-type semiconductor layer 120p, and is electrically connected to the p-type semiconductor layer 120p. The light reflective electrode 130 has a function of flowing a current to a wider region of the p-type semiconductor layer 120p. Further, by providing the light-reflective electrode 130 so as to cover substantially the entire upper surface 120pa of the p-type semiconductor layer 120p, the upper surface of the light emitting element 100A in FIG. 4 and FIG. Light traveling toward the opposite side can be reflected by the light reflective electrode 130 toward the first substrate 111 of the light emitting element 100A, and an effect of improving light extraction efficiency can be obtained. As the light-reflective electrode 130, for example, a film of Ag or Al, or an alloy containing at least one of them can be used. The light reflective electrode 130 can be formed, for example, by forming a metal film or an alloy film by a sputtering method and then removing an unnecessary portion by an etching method.

The first insulating layer 140 is provided on the light reflective electrode 130. An example of the material of the first insulating layer 140 is an oxide or a nitride containing at least one selected from the group consisting of Si, Ti, Zr, Nb, Ta, Al, and Hf. The first insulating layer 140 is typically an insulating layer formed of SiO ₂ and covers the semiconductor structure 112A and the light reflective electrode 130. Note that an SiN layer as a barrier layer that suppresses migration of the material of the light reflective electrode 130 may be disposed between the light reflective electrode 130 and the first insulating layer 140.

  FIG. 7 schematically shows a state where the first insulating layer 140 is formed on the light reflective electrode 130. In FIG. 7, a hatched portion is a portion where the material of the first insulating layer 140 is provided. As schematically shown in FIG. 7, the first insulating layer 140 includes first through holes 141 provided at positions corresponding to the extending portions Ep1 to Ep4 of the first region R1 of the n-type semiconductor layer 120n. And a second through-hole 142 provided above the second region R2 of the n-type semiconductor layer 120n. Here, four first through holes 141 are provided along the second long side LS2 of the rectangular outer shape of the n-type semiconductor layer 120n. By arranging the extending portion Ep along one long side (in this example, the second long side LS2) of the rectangular outer shape, luminance unevenness can be made less noticeable.

  At the positions of the four first through holes 141, the extensions Ep1 to Ep4 are exposed from the first insulating layer 140. In addition, at the position of the second through hole 142, the surface of the light reflective electrode 130 is exposed from the first insulating layer 140. The shape of the first through hole 141 can be, for example, a shape having a larger opening diameter in the Y direction than in the X direction. By adopting such a shape, even when the n-type semiconductor layer 120n has a long external shape as in the present embodiment, the first surface of the n-type semiconductor layer 120n described later includes a first The area of the portion connected to the internal electrode 150n can be made relatively large, and the reduction in the area of the active layer 120a due to the provision of the first through hole 141 can be suppressed. Needless to say, the shape and number of the second through holes 142 shown in FIG. 7 are merely examples. The shape of each of the first through holes 141 is not limited to the illustrated shape.

  As shown in FIG. 4, a first internal electrode 150n and a second internal electrode 150p are provided on the first insulating layer 140. As an example of the material of the first internal electrode 150n and the second internal electrode 150p, Ag or Al, or an alloy containing at least one of them can be used. In particular, Al and an Al alloy can be advantageously used as a material of the first internal electrode 150n and the second internal electrode 150p because high reflectivity is obtained and migration is less likely to occur as compared with Ag.

  FIG. 8 schematically shows a state in which a first internal electrode 150n and a second internal electrode 150p are formed on the first insulating layer 140. The first internal electrode 150n is electrically connected to the n-type semiconductor layer 120n at the positions of the extensions Ep1 to Ep4 via the first through-hole 141. The second internal electrode 150p is electrically connected to the light reflective electrode 130 via the second through hole 142. That is, the second internal electrode 150p has an electrical connection with the p-type semiconductor layer 120p.

FIG. 4 is referred to again. On the first internal electrode 150n and the second internal electrode 150p, a second insulating layer 160 that covers these electrodes is provided. The second insulating layer 160 is formed of an inorganic material such as SiO ₂ like the first insulating layer 140, and electrically separates the first internal electrode 150n and the second internal electrode 150p from each other.

  FIG. 9 shows a state where a second insulating layer 160 is further formed on the first internal electrode 150n and the second internal electrode 150p. The second insulating layer 160 has a third through hole 163 at a position overlapping the first internal electrode 150n in a top view, and has a fourth through hole 164 at a position overlapping the second internal electrode 150p. As schematically shown in FIG. 9, the surface of the first internal electrode 150 n is located at the position of the third through hole 163, and the surface of the second internal electrode 150 p is located at the position of the fourth through hole 164. Exposure from 160. It goes without saying that the shape and number of each of the third through hole 163 and the fourth through hole 164 are not limited to the example of FIG.

  For example, as shown in FIG. 4, the above-mentioned first external electrode 170An and second external electrode 170Ap are located on the second insulating layer 160. As can be seen from FIGS. 3 and 4, the first external electrode 170An is electrically connected to the first internal electrode 150n via the third through hole 163 of the second insulating layer 160. That is, the first external electrode 170An is electrically connected to the n-type semiconductor layer 120n via the first internal electrode 150n connected to the n-type semiconductor layer 120n at the positions of the extensions Ep1 to Ep4 of the n-type semiconductor layer 120n. Connected. On the other hand, the second external electrode 170Ap is electrically connected to the second internal electrode 150p through the fourth through hole 164 of the second insulating layer 160, thereby connecting the second internal electrode 150p and the light-reflective electrode 130. It is electrically connected to the p-type semiconductor layer 120p through this.

  FIG. 10 shows the semiconductor structure 112A of the light emitting element 100A, and the first external electrode 170An and the second external electrode 170Ap. In FIG. 10, the position of the first through hole 141 of the first insulating layer 140 is also shown by a dotted line.

  The outer shapes of the first external electrode 170An and the second external electrode 170Ap typically have a plurality of corners when viewed from above. As shown in FIG. 10, here, the shape of the first external electrode 170An and the second external electrode 170Ap in a top view is a rectangular shape including four corners. In the configuration illustrated in FIG. 10, the shape of the first external electrode 170An in a top view is substantially rectangular and includes four corners CA1 to CA4. Similarly, in this example, the shape of the second external electrode 170Ap in a top view is also generally rectangular and includes four corners CA5 to CA8.

  Examples of the material of the first external electrode 170An and the second external electrode 170Ap include Ti, Pt, Rh, Au, Ni, Ta, Zr, and the like. The first external electrode 170An and the second external electrode 170Ap may have a single-layer structure or a stacked structure in which a plurality of layers are stacked. The first external electrode 170An and the second external electrode 170Ap may be, for example, metal layers having a stacked structure in which a Ti layer, a Pt layer, and an Au layer are stacked in this order.

  As schematically illustrated in FIG. 10, in the embodiment of the present disclosure, each of the plurality of extending portions Ep provided in the first region R1 of the n-type semiconductor layer 120n is formed of the n-type semiconductor layer 120n in a top view. On the upper surface, it is not arranged at a position overlapping with the plurality of corners of the first external electrode 170An, and on the upper surface of the n-type semiconductor layer 120n, at a position overlapping with the plurality of corners of the second external electrode 170Ap. Not even placed. In the example illustrated in FIG. 10, each of the four extending portions Ep1 to Ep4 arranged along the second long side LS2 of the rectangular outer shape of the n-type semiconductor layer 120n is a corner CA1 to CA4 of the first external electrode 170An. And a position other than a position overlapping any of the corners CA5 to CA8 of the second external electrode 170Ap.

  Further, here, the first external electrode 170An and the second external electrode 170Ap have a concave portion at a position corresponding to each extension portion Ep of the first region R1 in a top view. In the illustrated example, the outer shape of the first external electrode 170An when viewed from above has a concave portion CV1 as a first concave portion at a position corresponding to the extending portion Ep1, and a second external portion at a position corresponding to the extending portion Ep2. It has a concave portion CV2 as a concave portion. Similarly, the outer shape of the second external electrode 170Ap in a top view has a concave portion CV3 as a third concave portion at a position corresponding to the extended portion Ep3, and a fourth concave portion at a position corresponding to the extended portion Ep4. Of the concave portion CV4. That is, in this example, the first external electrode 170An and the second external electrode 170Ap have a shape that does not overlap with the plurality of extending portions Ep arranged in the first region R1 of the n-type semiconductor layer 120n in a top view. ing. By adopting a shape having a concave portion at a position corresponding to the extension portion Ep as the outer shape of the first external electrode 170An and the second external electrode 170Ap in a top view, the p-type semiconductor layer 120p of the semiconductor structure 112A is selectively formed. In the vicinity of the region where the n-type semiconductor layer 120n is exposed and the n-type semiconductor layer 120n is exposed.

  The light emitting element 100A can be mounted on the support 200 by electrically and physically connecting the first external electrode 170An and the second external electrode 170Ap to the first wiring 210 and the second wiring 220, respectively, by eutectic bonding. . The base 230 of the support 200 is formed of, for example, BT resin, and the first wiring 210 and the second wiring 220 on the support 200 are typically Cu wiring.

  FIG. 11 illustrates another example of an appearance of a light emitting device according to an embodiment of the present disclosure. 11A schematically includes the light emitting element 100, a light transmitting member 182, and a light reflecting member 190A. As illustrated, the light reflective member 190A has a substantially rectangular parallelepiped shape longer in the Y direction than in the X direction, similarly to the light reflective member 190 in the light emitting device 300 illustrated in FIG.

  Compared to the light emitting device 300 described with reference to FIG. 1, the light emitting device 300A shown in FIG. 11 does not include the support 200 that supports the light emitting element 100. However, the light emitting device 300A has a set of a first wiring 210A and a second wiring 220A arranged on the lower surface 190b of the light reflective member 190A, which is located on the opposite side to the upper surface 300a.

  FIG. 12 schematically shows a cross section taken along the line XII-XII of FIG. 11, in other words, a cross section corresponding to FIG. 2 described above. As shown in FIG. 12, the first wiring 210A is connected to the first external electrode 170An of the light emitting element 100, and the second wiring 220A is connected to the second external electrode 170Ap. As in this example, the first wiring connected to the first external electrode of the light emitting element and the second wiring connected to the second external electrode are placed on the lower surface of the light emitting device opposite to the upper surface 300a. It may be provided. In the embodiment of the present disclosure, the base 230 that supports the first wiring and the second wiring is not essential.

(Suppression of leak generation)
As will be described later with reference to examples, according to the study of the present inventors, an external electrode for electrically and physically connecting a light emitting element to a support such as a printed circuit board has a corner portion in a top view. When the external electrode has such an outer shape, when the external electrode is eutectic-bonded to a wiring such as a printed circuit board, thermal stress tends to concentrate at the corner of the external electrode. Here, a structure for electrically connecting the n-type semiconductor layer and an electrode located above the n-type semiconductor layer and inside the light emitting structure, for example, a through-hole provided in the insulating layer is externally viewed from the top. If the insulating layer overlaps with a position overlapping the corner of the electrode, cracks may occur in the insulating layer due to thermal stress, and a leak may occur between the external electrode and the electrode located inside the light emitting structure. In particular, when AuSn is used as a material of a joining member used for eutectic bonding, a stronger bond can be formed as compared with a case where AgSn or CuSn is used, but AuSn has a higher melting point because it has a higher melting point. Thermal stress generated in the electrode is likely to increase. Further, when the wiring on the printed circuit board to which the light emitting element is connected is a wiring formed of Cu having a relatively high thermal conductivity and a coefficient of thermal expansion among metals, it is easy to secure heat dissipation, A larger thermal stress is easily generated in the external electrode due to a difference in thermal expansion coefficient from the light emitting element.

  The present inventors have found that by providing a through hole at a position avoiding a corner of an external electrode, it is possible to suppress the occurrence of leakage due to thermal stress and to improve the reliability of the light emitting element. Hereinafter, this point will be described with reference to the drawings.

  FIG. 13 shows, as a comparative example, a light-emitting element in which a plurality of extending portions and a plurality of through holes provided in an insulating layer are arranged at positions overlapping corner portions of an external electrode. The main difference between the light-emitting element 500 shown in FIG. 13 and the light-emitting element 100A shown in FIG. 3 and the like is that the light-emitting element 500 is replaced with a first external electrode 170An and a second external electrode 170Ap, respectively. This is a point having the first external electrode 570n and the second external electrode 570p.

  FIG. 13 is a schematic perspective view of the light emitting element 500 as viewed from the lower surface side, similarly to FIG. 3, and the first external electrode 570n and the second external electrode 570p are hatched for easy understanding. is there. As shown in FIG. 13, in this comparative example, the outer shape of the first external electrode 570n has a substantially rectangular shape, and the concave portion CV5 is formed at the corner located at the lower left on the paper surface among the four corners of the rectangular outer shape. Having. The concave portion CV5 is located at a position overlapping the extension portion Ep2 in a top view. Similarly, the outer shape of the second external electrode 570p also has a substantially rectangular shape, and has a concave portion CV6 at a corner located at the lower right on the paper surface among the four corners of the rectangular outer shape. The concave portion CV6 is located at a position overlapping the extension portion Ep3 in a top view.

  FIG. 14 schematically shows a cross section taken along line XIV-XIV of FIG. The cross section at the position of line IV-IV in FIG. 13 can be substantially the same as the cross section shown in FIG. Therefore, here, illustration of the IV-IV section in FIG. 13 and description of the structure appearing in the IV-IV section are omitted.

  In this comparative example, the extension portion Ep2 is located almost directly below the concave portion CV5 provided in the first external electrode 570n, and the first through hole 141 of the first insulating layer 140 is also located almost directly below the concave portion CV5. . As schematically shown in FIG. 14, a part of the first internal electrode 150n is filled in the first through-hole 141 to electrically connect the first internal electrode 150n to the n-type semiconductor layer 120n. A via 150nv is formed.

  As schematically shown in FIG. 14, the first internal electrode 150n covers the side of the first insulating layer 140 near the first through hole 141, and is connected to the n-type semiconductor layer 120n. According to the study of the present inventors, when thermal stress due to eutectic junction is concentrated on a region of the n-type semiconductor layer 120n that is not covered by the active layer 120a and the p-type semiconductor layer 120p and on the periphery thereof, the first For example, cracks may occur in the insulating layer 140 at, for example, a step portion. When, for example, a crack occurs in the first insulating layer 140, the material of the electrode disposed inside the light emitting structure migrates to cause a gap between the p-side electrode and the n-side electrode (for example, the light reflective electrode and the n-side electrode). (Internal electrode). That is, a leak may occur and the reliability of the light emitting element may be reduced.

  On the other hand, in the present embodiment, at a position where there is a possibility that thermal stress is concentrated, the corner does not overlap with any of the corners CA1 to CA4 of the first external electrode 170An and the corners CA5 to CA8 of the second external electrode 170Ap. , An extension Ep in which the first through hole 141 of the first insulating layer 140 is provided. Thereby, for example, an effect of suppressing generation of a leak due to a short circuit between the light reflective electrode 130 and the first internal electrode 150n can be obtained. This is because a conductive structure such as a via 150nv that forms an electrical connection with the n-type semiconductor layer 120n and the concentration of thermal stress around the conductive structure are avoided, and cracks are generated in the first insulating layer 140. It is presumed that this can be avoided.

  As described above, according to the embodiment of the present disclosure, it is possible to suppress the occurrence of a leak inside the light emitting element and improve the reliability of the light emitting element. The first external electrode 170An and the second external electrode 170Ap are arranged at a position other than the position overlapping with the plurality of extending portions Ep in a top view, or, as illustrated in FIG. 10, the first external electrode 170An and the second external electrode 170An. By adopting a shape that does not overlap the plurality of extending portions Ep as viewed from above as the outer shape of the 170 Ap, the occurrence of leak can be more advantageously suppressed.

(Relationship between shape of external electrode and arrangement of multiple extension parts)
Hereinafter, the relationship between the shapes of the first external electrode 170An and the second external electrode 170Ap and the arrangement of the plurality of extensions Ep will be described in more detail.

  FIG. 15 is a view for explaining an example of the relationship between the shapes of the first external electrode 170An and the second external electrode 170Ap and the arrangement of the plurality of extending portions Ep. As in FIG. It is a figure which extracts and shows the semiconductor structure 112A of 100A, the 1st external electrode 170An, and the 2nd external electrode 170Ap.

  In the configuration illustrated in FIG. 15, the first external electrode 170An and the second external electrode 170Ap have a substantially rectangular outer shape. The outer shape of the first external electrode 170An has a pair of a first short side SS1 and a second short side SS2 facing each other. Similarly, here, the outer shape of the second external electrode 170Ap has a set of a third short side SS3 and a fourth short side SS4 facing each other. In this example, the external shape of the first external electrode 170An in a top view and the external shape of the second external electrode 170Ap in a top view are both generally rectangular, but the first external electrode 170An and the second external electrode The shape of the 170 Ap in the top view does not need to match.

  In the illustrated example, each of the first short side SS1 to the fourth short side SS4 is perpendicular to the rectangular second long side LS2 of the n-type semiconductor layer 120n. As illustrated, the first short side SS1 is located farther from the second external electrode 170Ap than the second short side SS2, and the third short side SS3 is closer to the first external electrode 170An than the fourth short side SS4. Located nearby.

  Here, the first region R1 of the n-type semiconductor layer 120n has first to fourth extensions Ep1 to Ep4. As schematically shown in FIG. 15, a virtual first line perpendicular to the second long side LS2 of the outer shape of the n-type semiconductor layer 120n and passing through the center of the rectangular outer shape of the first external electrode 170An in a top view. Assuming L1, the extension Ep1, which is the first extension, is located between the virtual first line L1 and the above-described first short side SS1. The extension Ep2, which is the second extension, is located between the virtual first line L1 and the above-described second short side SS2. Therefore, in this example, the first through hole 141 provided on the extension portion Ep1 and the concave portion CV1 provided in the first external electrode 170An are also located between the first line L1 and the first short side SS1. I have. Further, the first through hole 141 provided on the extension Ep2 and the concave portion CV2 provided in the first external electrode 170An are also located between the first line L1 and the second short side SS2.

  Similarly, when assuming a virtual second line L2 perpendicular to the second long side LS2 and passing through the center of the rectangular outer shape of the second external electrode 170Ap in top view, the extension that is the third extension portion The part Ep3 is located between the virtual second line L2 and the third short side SS3. The extension Ep4, which is the fourth extension, is located between the virtual second line L2 and the fourth short side SS4. The first through hole 141 provided on the extension portion Ep3 and the concave portion CV3 provided in the second external electrode 170Ap are also located between the second line L2 and the third short side SS3. Further, the first through hole 141 provided on the extension portion Ep4 and the concave portion CV4 provided in the second external electrode 170Ap are also located between the second line L2 and the fourth short side SS4.

  In the configuration illustrated in FIG. 15, the distance between the extended portion Ep1 and the first line L1 shown by a double arrow da1 in FIG. 15 is the distance between the extended portion Ep1 and the first short line shown by a double arrow da2 in FIG. 15. It is smaller than the distance between the side SS1. Here, the distance between a certain extension and a certain virtual line or a certain side is a distance from the center of the certain extension to the virtual line or the side when measured along the second long side LS2. Point to. As in this example, when viewed from above, the first short side SS1 where the corner CA2 of the first external electrode 170An is located is compared with the first line L1 passing through the center of the first external electrode 170An as a reference. By disposing the extension portion Ep1 at a position further away from the corner portion, it is possible to reduce the influence of thermal stress generated in the corner CA2 near the extension portion Ep1. Similarly, in this example, the distance between the extending portion Ep2 and the first line L1, which is indicated by a double arrow da3 in FIG. 15, is the distance between the extending portion Ep2 and the second short side, which is indicated by a double arrow da4 in FIG. It is smaller than the distance from SS2. That is, the extension Ep2 is located farther from the second short side SS2 where the corner CA3 of the first external electrode 170An is located than when the first line L1 is used as a reference, and the corner CA3 Can be expected to have an effect of suppressing the occurrence of leaks caused by thermal stress generated in the substrate.

  In this example, the arrangement similar to the extension parts Ep1 and Ep2 is also adopted for the extension parts Ep3 and Ep4. That is, when assuming a virtual second line L2 perpendicular to the second long side LS2 and passing through the center of the rectangular outer shape of the second external electrode 170Ap, the extending portion Ep3 is located at the top in a plan view. It is located between the second line L2 and the third short side SS3. As schematically shown in FIG. 15, the distance between the extension Ep3 and the second line L2, which is indicated by a double arrow db1 in FIG. 15, is different from the distance between the extension Ep3, which is indicated by a double arrow db2 in FIG. It is smaller than the distance between the three short sides SS3. The extension portion Ep3 is arranged at a position further away from the third short side SS3 where the corner CA6 of the second external electrode 170Ap is located as compared with the case where the second line L2 is used as a reference. The distance between the extension Ep4 and the second line L2, which is indicated by a double arrow db3 in FIG. 15, is between the extension Ep4 and the fourth short side SS4, which is indicated by a double arrow db4 in FIG. Less than the distance. The extension portion Ep4 is arranged at a position further away from the fourth short side SS4 where the corner CA7 of the second external electrode 170Ap is located, as compared with the case where the second line L2 is used as a reference. Therefore, an effect of suppressing the occurrence of a leak at the position of the extension portion Ep3 or Ep4 due to the thermal stress generated at the corner portions CA6 and CA7 can be expected.

(Modification)
FIG. 16 illustrates another example of the light emitting device according to the embodiment of the present disclosure. A light-emitting element 100B illustrated in FIG. 16 is another example of the light-emitting element 100 described with reference to FIGS. FIG. 16 is a schematic perspective view of the light emitting element 100B viewed from the lower surface side, similarly to FIG. The cross section at the position of the IV-IV line and the cross section at the position of the VV line in FIG. 16 can be substantially similar to the cross section shown in FIGS. 4 and 5, respectively. Therefore, the illustration of the IV-IV section and the VV section in FIG. 16 and the description of the structure appearing in these sections are omitted here.

  Compared to the light emitting element 100A described with reference to FIG. 3 and the like, the light emitting element 100B shown in FIG. 16 has a first external electrode 170Bn and a second external electrode 170An instead of the first external electrode 170An and the second external electrode 170Ap. It has an electrode 170Bp. In the configuration illustrated in FIG. 16, the first external electrode 170Bn has a substantially rectangular outer shape including a pair of a first short side SS1 and a second short side SS2 facing each other. Similarly, the second external electrode 170Bp also has a substantially rectangular outer shape including a pair of the third short side SS3 and the fourth short side SS4 facing each other. Each of the first short side SS1 to the fourth short side SS4 is perpendicular to the second long side LS2 of the rectangular outer shape of the n-type semiconductor layer 120n.

  FIG. 17A schematically shows the semiconductor structure in the light emitting element 100B shown in FIG. 16, and the first external electrode 170Bn and the second external electrode 170Bp. The semiconductor structure 112B shown in FIG. 17A includes an n-type semiconductor layer 120n having a first region R1 and a second region R2, and an active layer (not shown in FIG. 17A) located on the second region R2 of the n-type semiconductor layer 120n. 120a and a p-type semiconductor layer 120p on the active layer 120a. Similarly to the above-described example, the first region R1 of the n-type semiconductor layer 120n includes an outer peripheral portion Pp located on the outer periphery of the second region R2 in a top view, and a plurality of extending portions extending from the outer peripheral portion Pp to the second region R2. Extension part Ep.

  However, here, the first region R1 of the n-type semiconductor layer 120n includes three extending portions Ep1 to Ep3 arranged along the second long side LS2 of the n-type semiconductor layer 120n. 17A, similarly to FIG. 6, a portion corresponding to the extended portions Ep1 to Ep3 in the first region R1 is shown by hatching. Of the extending portions Ep1 to Ep3, the extending portion Ep3 is located between the first external electrode 170Bn and the second external electrode 170Bp in a top view. In the examples shown in FIGS. 16 and 17A, the area of the removed portion of the p-type semiconductor layer 120p and the active layer 120a is smaller than that of the examples described with reference to FIGS. This is advantageous from the viewpoint of suppressing a reduction in the area of the portion.

  In the configuration illustrated in FIG. 17A, the extension Ep1 is a virtual first line perpendicular to the second long side LS2 of the outer shape of the n-type semiconductor layer 120n and passing through the center of the rectangular outer shape of the first external electrode 170Bn. Located on L1. The extension Ep2 is located on a virtual second line L2 perpendicular to the second long side LS2 and passing through the center of the rectangular outer shape of the second external electrode 170Bp. By employing such an arrangement, the extension Ep1 is arranged at a position away from the corners CA2 and CA3 of the first external electrode 170Bn, and at a position away from the corners CA6 and CA7 of the second external electrode 170Bp. The extension Ep2 can be arranged. In this example, the extension Ep3 is located on a virtual third line L3 perpendicular to the second long side LS2 and passing through the center of the second long side LS2.

  As schematically shown in FIG. 17A, here, the rectangular external shape of the first external electrode 170Bn has a concave portion CV1 as a first concave portion at a position corresponding to the extension portion Ep1 in a top view, The rectangular outer shape of the external electrode 170Bp has a concave portion CV2 as a second concave portion at a position corresponding to the extending portion Ep2 in a top view. That is, also in this example, the first external electrode 170Bn and the second external electrode 170Bp have a shape that does not overlap with any of the extending portions Ep1 to Ep3 in a top view.

  Similarly to the example described with reference to FIGS. 3 to 15, in the examples shown in FIGS. 16 and 17A as well, a conductive layer that forms an electrical connection between the n-type semiconductor layer 120 n and the first internal electrode 150 n is provided. The extension Ep on which the structure can be arranged is arranged at a position other than the position overlapping the corner of the first external electrode 170Bn and at a position other than the position overlapping the corner of the second external electrode 170Bp. Thereby, it is possible to suppress the occurrence of a short circuit, for example, between the light reflective electrode 130 and the first internal electrode 150n due to the thermal stress generated in the first external electrode 170Bn and the second external electrode 170Bp.

  FIG. 17B shows still another example of the light emitting device according to the embodiment of the present disclosure. A light-emitting element 100C illustrated in FIG. 17B is still another example of the light-emitting element 100 described with reference to FIGS. FIG. 17B is a schematic perspective view of the light emitting element 100C viewed from the lower surface side, similarly to FIGS. 3 and 16.

  Compared to the light emitting element 100B described with reference to FIG. 16, the light emitting element 100C shown in FIG. 17B has a first external electrode 170Cn and a second external electrode instead of the first external electrode 170Bn and the second external electrode 170Bp. It has 170 Cp. The first external electrode 170Cn and the second external electrode 170Cp have the same configuration as the first external electrode 170Bn and the second external electrode 170Bp, respectively, except that the outer shape is different. In FIG. 17B, the shapes of the first external electrode 170Cn and the second external electrode 170Cp are indicated by hatching for easy understanding.

  In the configuration illustrated in FIG. 17B, from the outer edge of the light-reflective electrode 130 to the outer edge of the external electrode (the first external electrode 170Cn or the second external electrode 170Cp) along the rectangular longitudinal direction of the n-type semiconductor layer 120n. The distance is larger than the distance from the outer edge of the light-reflective electrode 130 to the outer edge of the external electrode along the rectangular short direction of the n-type semiconductor layer 120n. For example, the distance from the outer edge of the light reflective electrode 130 located on the shorter side of the n-type semiconductor layer 120n to the outer edge of the second external electrode 170Cp (indicated schematically by a double-headed arrow Lg in FIG. 17B) is It is larger than the distance from the outer edge of the light reflective electrode 130 located on the long side of the n-type semiconductor layer 120n to the outer edge of the second external electrode 170Cp (indicated schematically by a double arrow Sg in FIG. 17B). Similarly, the distance from the outer edge of the light reflective electrode 130 located on the short side of the n-type semiconductor layer 120n to the outer edge of the first external electrode 170Cn is equal to the length of the n-type semiconductor layer 120n of the light reflective electrode 130. The distance from the outer edge located on the side to the outer edge of the first external electrode 170Cn may be larger.

  A light-emitting element having a rectangular outer shape in a top view may have a warp such that an end is directed to the −Z direction in the drawing. When the light-emitting element having such a warp is mounted on a member having a wiring (for example, the above-described support 200) by eutectic bonding, the wiring and the electrode on the light-emitting element side are joined, so that the end of the light-emitting element Therefore, a stress is applied in such a direction as to correct the warpage. At this time, the larger the area of the electrode on the light emitting element side joined to the wiring by eutectic bonding, the greater the joining strength can be obtained, but the load on the end of the light emitting element also increases. According to the study of the present inventors, this stress may increase as the distance from the center of the light emitting element increases. For this reason, cracks may occur in the light-emitting element, particularly at positions near the short sides of the light-emitting element, due to the stress generated by the eutectic bonding.

  In the example shown in FIG. 17B, the distance from the outer edge of the light-emitting element to the outer edge of the light-emitting element with respect to the position of the outer edge of the light-reflective electrode 130 with respect to the longitudinal direction of the light-emitting element is rectangular. It is bigger than that. According to such a configuration, it is possible to obtain an effect of alleviating a stress applied to a portion close to the rectangular short side of the light emitting element due to the eutectic junction, and therefore, it is possible to reduce the possibility of occurrence of cracks. it can. Note that the first external electrode 170Cn may have a smaller area than the above-described first external electrode 170Bn. Similarly, the second external electrode 170Cp may have a smaller area than the above-described second external electrode 170Bp.

  In the illustrated example, the distance from the outer edge of the light-reflective electrode 130 to the outer edge of the external electrode, which is located on the short side of the n-type semiconductor layer 120n, is equal to the length in the longitudinal direction (X direction in the drawing) of the light emitting element. For example, the range is 3% or more and 7% or less, more preferably 4% or more and 5% or less. The distance indicated by the double arrow Lg in FIG. 17B may be, for example, about 40 μm to 50 μm. On the other hand, the distance from the outer edge of the light-reflective electrode 130 to the outer edge of the external electrode, which is located on the long side (for example, the second long side LS2) of the n-type semiconductor layer 120n, is determined in the short direction of the light emitting element (Y in the drawing). For example, the length is in the range of 10% or more and 15% or less, and more preferably in the range of 12% or more and 15% or less. The distance indicated by the double-headed arrow Sg in FIG. 17B may be, for example, about 20 μm to 30 μm. In addition, the distance from the outer edge of the light reflective electrode 130 to the outer edge of the external electrode, which is located on the second long side LS2 side, and the distance between the outer edge of the light reflective electrode 130, which is located on the first long side LS1 side, and the external electrode The distance to the outer edge may be equivalent.

  In the short direction (X direction in the figure) of the light emitting element, the magnitude of warpage is generally smaller than that in the longitudinal direction (Y direction in the figure) of the light emitting element. Even if the light emitting element is brought close to the outer edge of the light emitting element 130, it is difficult for the light emitting element to crack. By making the position of the outer edge of the external electrode closer to the outer edge of the light-reflective electrode 130 in the short direction (X direction in the drawing) of the light emitting element, it is possible to avoid that the area of the external electrode becomes too small, and therefore, to reduce the bonding strength. Excessive reduction can be suppressed.

  The distance from the outer edge of the light-reflective electrode 130 to the outer edge of the external electrode at the position of the extended portion Ep (extended portion Ep1, Ep3) of the n-type semiconductor layer 120n (schematically indicated by a double arrow Mg in FIG. 17B). .) Can be made smaller than the distance Sg described above. The distance from the outer edge of the light reflective electrode 130 to the outer edge of the external electrode at the position of the extension Ep may be, for example, about 10 μm to 20 μm. As described above, the stress applied to the end closer to the long side of the light emitting element tends to be smaller than the stress applied to the end closer to the short side. Therefore, in the short direction (X direction in the figure) of the light emitting element, the outer edge of the external electrode is easily brought closer to the outer edge of the light reflective electrode 130. As in this example, by reducing the distance from the outer edge of the light-reflective electrode 130 to the outer edge of the external electrode, for example, at the position of the extension portion Ep as compared with other portions, light emission due to stress on the light-emitting element is achieved. An extreme decrease in the area of the external electrode can be avoided while suppressing an increase in load on the end of the element. That is, it is possible to prevent the bonding strength from being extremely reduced due to the decrease in the area of the external electrode.

  Hereinafter, the relationship between the shape of the external electrode as viewed from above and the location where thermal stress tends to concentrate was examined by evaluating the magnitude of the shear stress applied to the external electrode by simulation.

(Reference Example 1)
As the shape of the external electrode when viewed from above, assuming the shapes of the first external electrode 170An and the second external electrode 170Ap having two concave portions corresponding to the two extending portions shown in FIG. When the device was mounted by eutectic bonding, the stress generated on the surface of the semiconductor layer during reflow cooling was calculated. The value obtained by the calculation is the shear stress τ _YX in the X direction in the XZ plane. In the following figures, the intensity of the shear stress is shown with shading based on the absolute value of τ _YX . . τ _YX is one of the components of the stress tensor. The calculation conditions are unified in all of the following Reference Examples 1 to 4, and the same value of the shear stress is shown with the same shading throughout FIGS. 18 to 21.

  FIG. 18 shows the calculation results for the sample of Reference Example 1. In FIG. 18, a dark portion indicates a region where the absolute value of the shear stress is large, and corresponds to a region where a relatively large thermal stress is applied. From the results shown in FIG. 18, it has been found that when, for example, a rectangular shape is employed as the outer shape of the external electrode, it is highly likely that stress is particularly concentrated at the corners CA <b> 1 to CA <b> 8 in joining to the support 200 or the like. . It was also found that the thermal stress at the position on the side connecting the two corners was relatively small.

(Reference Example 2)
As the shape of the external electrode in a top view, the shapes of the first external electrode 170Bn and the second external electrode 170Bp having one concave portion corresponding to one extending portion shown in FIG. In the same manner as the sample, the absolute value of the shear stress _τYX was calculated.

  FIG. 19 shows calculation results for the sample of Reference Example 2. Similarly to the result shown in FIG. 18, it was found that the stress shown in FIG. 19 is highly likely to be concentrated particularly at the corners CA1 to CA8 of the external electrode.

(Reference Example 3)
As in the example described with reference to FIG. 13, it is assumed that the extension of the n-type semiconductor layer is located at a position overlapping the corner of the rectangular external electrode, and the same as in the sample of Reference Example 1. , The absolute value of the shear stress τ _YX was calculated.

  FIG. 20 shows the calculation results for the sample of Reference Example 3. From the results shown in FIG. 20, as compared with the positions of the extensions Ep1 and Ep4 located on the rectangular sides of the external electrode, the extension Ep2 at the position overlapping the corner CA3 of the external electrode and the periphery thereof, In addition, it was found that thermal stress could be concentrated on the extension Ep3 at a position overlapping the corner CA6 of the external electrode and on the periphery thereof.

(Reference Example 4)
Assuming a semiconductor structure having no extension in the n-type semiconductor layer, the absolute value of the shear stress _τYX was calculated in the same manner as in the sample of Reference Example 1.

  FIG. 21 shows the calculation results for the sample of Reference Example 4. From the results shown in FIG. 21, it has been found that thermal stress tends to concentrate more on a position overlapping the corner than on a rectangular side of the external electrode.

  Based on the results shown in FIGS. 20 and 21 and the results shown in FIGS. 18 and 19, by disposing the extension at a position other than the position overlapping the corner of the external electrode, shearing of the extension and its surroundings is achieved. It has been found that stress can be reduced, and thermal stress can be prevented from concentrating on the extension and its surroundings, and cracking of the insulating layer at the position of the extension can be suppressed. According to the embodiment of the present disclosure, since the extension portion Ep is arranged so as to avoid the portion where the leak is likely to occur, it is possible to suppress the occurrence of the leak inside the light emitting structure.

  Embodiments of the present disclosure are useful for various illumination light sources, light sources for vehicles, light sources for displays, and the like. In particular, it can be advantageously applied to a backlight unit directed to a liquid crystal display device.

Reference Signs List 100, 100A to 100C Light emitting element 110, 110A Light emitting structure 111 First substrate 112A, 112B Semiconductor structure 120a Active layer 120n N-type semiconductor layer 120pp P-type semiconductor layer 130 Light reflective electrode 140 First insulating layer 141 First through hole 142 Second through hole 150n First internal electrode 150nv Via 150p Second internal electrode 160 Second insulating layer 163 Third through hole 164 Fourth through hole 170An to 170Cn, 570n First external electrode 170Ap to 170Cp, 570p Second external electrode 174 Light guide member 180 Wavelength conversion member 182 Light transmission member 190, 190A Light reflective member 200 Support 210, 210A First wiring 220, 220A Second wiring 230 Base 300, 300A Light emitting device 500 Light emitting device CA1 to CA8 External electrodes Corner CV1 CV6 Depression of external electrode LS1 First long side LS2 Second long side R1 First region R2 Second region Ep, Ep1-Ep4 Extension of first region Pp Outer periphery of first region SS1 First short side SS2 Second Short side SS3 3rd short side SS4 4th short side

Claims (13)

A first semiconductor layer of a first conductivity type having a first region and a second region located inside the first region; an active layer located on the second region; and a second layer located on the active layer. A semiconductor structure including a conductive type second semiconductor layer, wherein the first region has an outer peripheral portion located at an outer periphery of the second region in a top view, and each extends from the outer peripheral portion to the second region. A semiconductor structure, comprising:
A light reflective electrode located on the upper surface of the second semiconductor layer, the light reflective electrode directly covering the upper surface of the second semiconductor layer ;
A first insulating layer that covers the semiconductor structure and the light-reflective electrode, and has a first through-hole located at each extension of the first region and a second through-hole located at the second region;
A first internal electrode located on the first insulating layer and electrically connected to the first semiconductor layer via the first through hole;
A second internal electrode located on the first insulating layer and electrically connected to the light reflective electrode through the second through hole;
A second insulating layer that covers the first internal electrode and the second internal electrode and electrically insulates the first internal electrode and the second internal electrode from each other; a second insulating layer that is located on the first internal electrode; A second insulating layer having three through holes and a fourth through hole located on the second internal electrode;
A first external electrode having a plurality of corners electrically connected to the first internal electrode via the third through hole;
A second external electrode having a plurality of corners electrically connected to the second internal electrode via the fourth through-hole,
The first semiconductor layer has a rectangular outer shape in a top view,
The rectangular outer shape includes a first long side and a second long side opposed to each other,
The first external electrode and the second external electrode are arranged along the longitudinal direction of the rectangular shape of the first semiconductor layer,
The plurality of extending portions are arranged in a line along the second long side at a position closer to the second long side than the first long side,
Each of the plurality of extending portions of the first region includes a portion of the upper surface of the first semiconductor layer other than a position overlapping with the plurality of corners of the first external electrode in a top view, and the second external electrode The light emitting element is arranged at a position other than a position overlapping with the plurality of corners. The light emitting device according to claim 1 , wherein the first external electrode and the second external electrode have a shape that does not overlap with the plurality of extending portions when viewed from above. The outer shape of the first external electrode is a rectangular shape including a first short side and a second short side that are opposed to each other and are perpendicular to the second long side,
The outer shape of the second external electrode is a rectangular shape including a third short side and a fourth short side that are opposed to each other and are perpendicular to the second long side,
The first short side is located farther from the second external electrode than the second short side,
The third short side is closer to the first external electrode than the fourth short side,
The plurality of extending portions are a first extension positioned between a virtual first line perpendicular to the second long side and passing through the rectangular center of the first external electrode and the first short side. A projection, a second extension located between the first line and the second short side, and a virtual line perpendicular to the second long side and passing through the rectangular center of the second external electrode. A third extension portion located between the second line and the third short side, and a fourth extension portion located between the second line and the fourth short side. 3. The light emitting device according to 1 or 2 . A distance between the first extension and the first line is smaller than a distance between the first extension and the first short side;
The light emitting device according to claim 3 , wherein a distance between the second extension and the first line is smaller than a distance between the second extension and the second short side. The distance between the third extension and the second line is smaller than the distance between the third extension and the third short side,
The fourth distance between the extending portion and the second line, the fourth less than the distance between the extending portion and the fourth short side, the light emitting device according to claim 4. The first external electrode has a first recess and a second recess at positions corresponding to the first extension and the second extension in a top view, respectively.
The second external electrode according to any one of claims 3 to 5 , wherein the second external electrode has a third concave portion and a fourth concave portion at positions corresponding to the third extension portion and the fourth extension portion, respectively, when viewed from above. Light emitting element. The outer shape of the first external electrode is a rectangular shape including a first short side and a second short side that are opposed to each other and are perpendicular to the second long side,
The outer shape of the second external electrode is a rectangular shape including a third short side and a fourth short side that are opposed to each other and are perpendicular to the second long side,
The plurality of extending portions are a first extending portion which is perpendicular to the second long side and is located on a virtual first line passing through the rectangular center of the first external electrode, and the second long side 3. The light-emitting element according to claim 1, further comprising a second extension portion that is located on a virtual second line passing through the rectangular center of the second external electrode. The first external electrode has a first recess at a position corresponding to the first extension in a top view,
The light emitting device according to claim 7 , wherein the second external electrode has a second concave portion at a position corresponding to the second extending portion in a top view. The plurality of extending portions are third extending portions located between the first external electrode and the second external electrode, and are perpendicular to the second long side and centered on the second long side. The light-emitting device according to claim 7 , further comprising a third extension located on a virtual third line passing through. The rectangular outer shape of the first semiconductor layer includes a fifth short side and a sixth short side perpendicular to the first long side and the second long side and opposed to each other ,
The second external electrode is located closer to the fifth short side than the sixth short side,
Before Symbol distance to the outer edge of the front Symbol fifth short side of the front Symbol fifth short side edge or found before Symbol light reflective electrode of the second external electrodes, before Symbol second pre Symbol second outer electrode greater than the distance to the outer edge of the front Stories second long side of the outer edge or found before Symbol light reflective electrode on the long side, the light emitting device according to any one of claims 1 to 9.   The rectangular outer shape of the first semiconductor layer includes a fifth short side and a sixth short side perpendicular to the first long side and the second long side and opposed to each other,
  The second external electrode is located closer to the fifth short side than the sixth short side,
  The distance from the outer edge on the sixth short side of the first external electrode to the outer edge on the sixth short side of the light reflective electrode is from the outer edge on the second long side of the first external electrode. The light emitting device according to any one of claims 1 to 9, wherein the distance from the light reflective electrode to an outer edge of the second long side is larger than the distance.   The light emitting device according to claim 1, further comprising a light transmitting first substrate that supports the semiconductor structure. A light-emitting device according to any one of claims 1 to 12,
A second substrate having a first wiring electrically connected to the light emitting element via the first external electrode, and a second wiring electrically connected to the light emitting element via the second external electrode And a light emitting device.

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