Semiconductor light emitting devices

Abstract

A semiconductor light-emitting device includes: a light-emitting structure, which includes a first conductive type semiconductor layer, an active layer and a second conductive type semiconductor layer; a first transparent electrode layer on the second conductive type semiconductor layer; a first insulating layer on the first transparent electrode layer, the first insulating layer including a plurality of through holes; a reflective electrode layer on the first insulating layer, the reflective electrode layer being connected to the first transparent electrode layer through the plurality of through holes; and a transparent protective layer covering the upper surface and side surfaces of the reflective electrode layer, the transparent protective layer being located on a portion of the first insulating layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The entire contents of Korean Patent Application No. 10-2018-0009229, titled “Semiconductor Light Emitting Device”, filed on January 25, 2018 in the Korean Intellectual Property Office are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to semiconductor light emitting devices. Background Art

[0004] Compared with traditional light sources, semiconductor light emitting devices are generally referred to as next-generation light sources due to their inherent advantages (such as relatively long service life, low power consumption, fast response time, and environmental friendliness). In addition, semiconductor light emitting devices are very prominent as important light sources in various products (such as backlight sources of lighting devices or display devices). Summary of the invention

[0005] According to an example embodiment, a semiconductor light emitting device may include: a light emitting structure, the light emitting structure including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer; a first transparent electrode layer on the second conductive type semiconductor layer; a first insulating layer on the first transparent electrode layer, the first insulating layer including a plurality of through holes; a reflective electrode layer on the first insulating layer, the reflective electrode layer being connected to the first transparent electrode layer through the plurality of through holes; and a transparent protective layer covering an upper surface and a side surface of the reflective electrode layer, the transparent protective layer being located on a portion of the first insulating layer.

[0006] According to an example embodiment, a semiconductor light-emitting device may also include: a light-emitting structure, the light-emitting structure having a stacked structure of a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer, the light-emitting structure having a recessed area, in which the second conductive type semiconductor layer is etched, the active layer is etched, and a portion of the first conductive type semiconductor layer is etched, and the light-emitting structure has a mesa area arranged adjacent to the recessed area; a first transparent electrode layer arranged on the second conductive type semiconductor layer; a first insulating layer covering the first transparent electrode layer, the first insulating layer having a plurality of through holes arranged in the mesa area; a second transparent electrode layer arranged on the first insulating layer, the second transparent electrode layer contacting the first transparent electrode layer through the plurality of through holes; a reflective electrode layer arranged on the second transparent electrode layer; and a transparent protective layer covering the upper surface and side surfaces of the reflective electrode layer, the transparent protective layer being arranged on a portion of the first insulating layer.

[0007] According to an example embodiment, a semiconductor light emitting device may also include: a substrate;

[0008] At least one light emitting structure, comprising a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer sequentially stacked on the substrate; a first transparent electrode layer connected to the second conductive type semiconductor layer; a first insulating layer partially covering the first transparent electrode layer; a second transparent electrode layer passing through the first insulating layer and connected to the first transparent electrode layer; a reflective electrode layer connected to the second transparent electrode layer; a transparent protective layer covering the upper surface and side surfaces of the reflective electrode layer, the transparent protective layer being disposed on a portion of the first insulating layer; a first connecting electrode passing through the active layer and the second conductive type semiconductor layer and connected to the first conductive type semiconductor layer; and a second connecting electrode passing through the transparent protective layer and connected to the reflective electrode layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features will become apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings, in which:

[0010] Figure 1 illustrates a schematic plan view of a semiconductor light emitting device according to an example embodiment;

[0011] Figure 2 Example along Figure 1 A schematic cross-sectional view of line II' in FIG.

[0012] Figure 3A and 3B Illustrated Figure 2 A local magnified view of area A;

[0013] Figure 4 and Figure 5 illustrates a schematic cross-sectional view of a semiconductor light emitting device according to a modified example embodiment;

[0014] Figure 6 illustrates a schematic cross-sectional view of a semiconductor light emitting device according to another modified example embodiment;

[0015] Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 Schematic plan views illustrating stages in a method of manufacturing a semiconductor light emitting device according to an example embodiment;

[0016] Figure 8 , Fig.10 , Fig.12 , Fig.14 , Fig.16 , Fig.18 and Fig. 20 The corresponding Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 A schematic cross-sectional view of line II'; and

[0017] Fig.21 A schematic cross-sectional view illustrating an example of a package including a semiconductor light emitting device according to an example embodiment is illustrated. DETAILED DESCRIPTION

[0018] Hereinafter, example embodiments will be described with reference to the accompanying drawings.

[0019] Figure 1 is a plan view schematically illustrating a semiconductor light emitting device 10 according to an example embodiment, Figure 2 is schematically illustrated along Figure 1 A cross-sectional view of the area taken along line II' in FIG.

[0020] First, refer to Figure 1 and Figure 2 A semiconductor light emitting device 10 according to example embodiments is described.

[0021] refer to Figure 1 and Figure 2 According to the example embodiment, the semiconductor light emitting device 10 may include a substrate 105, a light emitting structure 110, a first insulating layer 130, a second insulating layer 150, a third insulating layer 160, a first transparent electrode layer 140, a second transparent electrode layer 142, a reflective electrode layer 144, a transparent protective layer 138, a first connection electrode 155n, a second connection electrode 155p, a first electrode pad 165n, a second electrode pad 165p, a first solder column 170n, and a second solder column 170p.

[0022] The substrate 105 may have a front surface 105s1 and a rear surface 105s2 opposite to the front surface 105s1. The substrate 105 may be a substrate for growing a semiconductor material, and may be formed of an insulating material, a conductive material, or a semiconductor material, such as sapphire, Si, SiC, MgAl 2 O 4 、MgO、LiAlO 2 、LiGaO 2 Or GaN. Sapphire can be used as a substrate for growing nitride semiconductor materials.

[0023] Throughout the present disclosure, although terms such as "front surface" and "rear surface" may be used to describe the relationship of one element to another element, embodiments are not limited by these terms. Therefore, terms such as "front surface" and "rear surface" may be replaced by terms such as "first surface" and "second surface" or terms such as "upper surface" and "lower surface" to describe elements in the present disclosure. Therefore, the front surface 105s1 and the rear surface 105s2 of the substrate 105 may be replaced by the upper surface 105s1 and the lower surface 105s2 of the substrate 105, or by the first surface 105s1 and the second surface 105s2 of the substrate 105.

[0024] The light emitting structure 110 may be disposed on the front surface 105s1 of the substrate 105. In some example embodiments, the front surface 105s1 of the substrate 105 may have a concavo-convex structure, which improves the crystallinity of the semiconductor layer configuring the light emitting structure 110 and the light emission efficiency of the light emitting structure 110. In example embodiments, the concavo-convex structure of the front surface 105s1 of the substrate 105 may have a dome-like convex shape, but is not limited thereto. For example, the concavo-convex structure of the front surface 105s1 of the substrate 105 may have various shapes, such as a quadrilateral or a triangle. In addition, the concavo-convex structure of the front surface 105s1 of the substrate 105 may be selectively formed or omitted.

[0025] In some example embodiments, the substrate 105 may be removed in a subsequent process. For example, the substrate 105 may be provided as a growth substrate for growing the light emitting structure 110, and then the substrate 105 may be removed by a separation process. The substrate 105 may be separated from the light emitting structure 110 by a laser lift-off (LLO) method, a chemical lift-off (CLO) method, or the like.

[0026] Although not shown in the drawings, a buffer layer may be further formed on the front surface 105s1 of the substrate 105. The buffer layer may be used to reduce lattice defects of the semiconductor layer grown on the substrate 105, and the buffer layer may be formed of an undoped semiconductor layer including a nitride material. The buffer layer may include, for example, undoped GaN, AlN, InGaN, etc., and may be grown to tens to hundreds of angstroms at a low temperature in the range of 500°C to 600°C. Here, the term “undoped” means that the semiconductor layer is not subjected to a separate doping process. However, the buffer layer may be omitted in some example embodiments.

[0027] The light emitting structure 110 may include a first conductive type semiconductor layer 115, an active layer 120, and a second conductive type semiconductor layer 125. For example, the first conductive type semiconductor layer 115, the active layer 120, and the second conductive type semiconductor layer 125 may be directly stacked on the substrate 105 in the aforementioned order.

[0028] The first conductive type semiconductor layer 115 may be grown from the front surface 105s1 of the substrate 105. The first conductive type semiconductor layer 115 may be a semiconductor layer doped with n-type impurities, for example, an n-type nitride semiconductor layer.

[0029] In a plan view, the first conductive type semiconductor layer 115 may have a quadrilateral shape, such as Figure 1 The first conductive type semiconductor layer 115 may have a first edge S1, a second edge S2, a third edge S3, and a fourth edge S4. Therefore, the first edge S1 and the third edge S3 may face each other, and the second edge S2 and the fourth edge S4 may face each other.

[0030] The second conductive type semiconductor layer 125 may be a semiconductor layer doped with p-type impurities, such as a p-type nitride semiconductor layer. In some example embodiments, the positions of the first conductive type semiconductor layer 115 and the second conductive type semiconductor layer 125 may be exchanged. The first conductive type semiconductor layer 115 and the second conductive type semiconductor layer 125 may include a composition formula of Al x In y Ga (1-x-y) N represents a material (here, 0≤x<1, 0≤y<1, and 0≤x+y<1). For example, the first conductive type semiconductor layer 115 and the second conductive type semiconductor layer 125 may include GaN, AlGaN, InGaN, or AlInGaN.

[0031] The active layer 120 may be inserted between the first conductive type semiconductor layer 115 and the second conductive type semiconductor layer 125. The active layer 120 may emit light having a predetermined amount of energy, which is generated by electron-hole recombination when the semiconductor light emitting device 10 is in operation. The active layer 120 may include a material having a smaller energy band gap than the first conductive type semiconductor layer 115 and the second conductive type semiconductor layer 125. For example, when the first conductive type semiconductor layer 115 and the second conductive type semiconductor layer 125 are GaN-based compound semiconductor materials, the active layer 120 may include an InGaN-based compound semiconductor material having a smaller energy band gap than the energy band gap of GaN. In addition, the active layer 120 may have a multiple quantum well (MQW) structure (e.g., InGaN / GaN structure), in which quantum well layers and quantum barrier layers are alternately stacked. However, the active layer 120 is not limited thereto, and may have a single quantum well (SQW) structure.

[0032] like Figure 2 As shown in , the light emitting structure 110 may include a recessed region E and a mesa region M disposed around the recessed region E, in which a portion of the second conductive type semiconductor layer 125, the active layer 120, and the first conductive type semiconductor layer 115 are etched, for example, in a top view, the mesa region M may completely surround the periphery of at least some of the recessed regions E. In the accompanying drawings, reference numeral "B" denotes a boundary B between the recessed region E and the mesa region M. The upper surface of the mesa region M may be higher than the upper surface of the recessed region E. In some example embodiments, the mesa region M may be narrowed toward its top. Therefore, the mesa region M may have an inclined side surface.

[0033] In some example embodiments, a portion of an upper surface of the recess region E may be defined as a first contact region CT1. In some example embodiments, at least a portion of an upper surface of the mesa region M may be defined as a second contact region CT2.

[0034] The mesa region M may be spaced apart from the first to fourth edges S1 to S4, and the recessed region E may be disposed between the mesa region M and the first to fourth edges S1 to S4. In addition, a plurality of recessed regions E having a circular shape and spaced apart from each other may be disposed in a central portion of the light emitting structure 110, such as Figure 1 shown.

[0035] The first transparent electrode layer 140 may be disposed, for example, directly on the second conductive type semiconductor layer 125 of the light emitting structure 110. The first transparent electrode layer 140 may be disposed at a second contact region CT2 of the second conductive type semiconductor layer 125 to be electrically connected to the second conductive type semiconductor layer 125.

[0036] The first insulating layer 130 may be, for example, directly disposed on the first transparent electrode layer 140. The first insulating layer 130 may cover a portion of the first conductive type semiconductor layer 115 and a portion of the second conductive type semiconductor layer 125, for example, the first insulating layer 130 may cover a portion of the upper surface of the first conductive type semiconductor layer 115 and a side surface of the second conductive type semiconductor layer 125. The first insulating layer 130 may include a plurality of through holes PD disposed in the mesa region M. The first insulating layer 130 may partially cover the first transparent electrode layer 140 in the mesa region M. In example embodiments, the plurality of through holes PD may be arranged in the mesa region M in a lattice pattern in which hexagons are closely arranged, but is not limited thereto. For example, the plurality of through holes PD may be arranged in various patterns, for example, a rectangular lattice pattern. Although the plurality of through holes PD are Figure 1 2 and 3. In the drawings, the through holes PD are shown as having circular cross-sectional areas, but they are not limited thereto, and for example, the plurality of through holes PD may have polygonal or annular cross-sectional areas.

[0037] In some example embodiments, the first transparent electrode layer 140 may include a plurality of through holes arranged to be offset from the plurality of through holes PD. In this case, the first insulating layer 130 may fill the plurality of through holes of the first transparent electrode layer 140 .

[0038] The first insulating layer 130 may be formed of a material having a refractive index lower than that of the second conductive type semiconductor layer 125. The first insulating layer 130 may include, for example, SiO 2 、SiN、TiO 2 , HfO and MgF 2 In some example embodiments, the first insulating layer 130 may have a distributed Bragg reflector (DBR) structure in which insulating layers having different refractive indices are alternately stacked.

[0039] The second transparent electrode layer 142 may be disposed on the first insulating layer 130 and may contact the first transparent electrode layer 140 through a plurality of through holes PD. The first transparent electrode layer 140 and the second transparent electrode layer 142 may include, for example, at least one of the following: indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), In 4 Sn 3 O 12 and zinc magnesium oxide (Zn (1-x) Mg x O, 0≤x≤1).

[0040] The reflective electrode layer 144 may be, for example, disposed directly on the second transparent electrode layer 142, for example, to conform to the second transparent electrode layer 142. For example, the reflective electrode layer 144 and the second transparent electrode layer 142 may completely overlap each other. The second transparent electrode layer 142 may be used to improve the adhesion between the reflective electrode layer 144 and the first insulating layer 130. The reflective electrode layer 144 may include, for example, Ag, Cr, Ni, Ti, Al, Rh, Ru, or a combination thereof.

[0041] The transparent protective layer 138 may cover the upper surface and the side surface of the reflective electrode layer 144 to protect the reflective electrode layer 144. The transparent protective layer 138 may cover the side surface of the second transparent electrode layer 142. The transparent protective layer 138 may include an upper portion R1 covering the upper surface of the reflective electrode layer 144 and having a convex surface, and a side portion R2 covering the side surface of the reflective electrode layer 144 and the side surface of the second transparent electrode layer 142 and having an inclined surface, for example, the upper portion R1 and the side portion R2 may be in contact with each other and continuous. For example, as Figure 2As shown in FIG. 1 , the transparent protective layer 138 may continuously cover all exposed surfaces of the second transparent electrode layer 142 and the reflective electrode layer 144, for example, the second transparent electrode layer 142 and the reflective electrode layer 144 may be encapsulated between the transparent protective layer 138 and the first insulating layer 130. By forming the transparent protective layer 138, the adhesion of the reflective electrode layer 144 may be improved, and the migration of the metal elements contained in the reflective electrode layer 144 may be suppressed.

[0042] The first insulating layer 130, the second transparent electrode layer 142, and the reflective electrode layer 144 may be configured as an omnidirectional reflector. The omnidirectional reflector may increase the reflectivity of light emitted from the active layer 120, thereby improving light extraction efficiency.

[0043] The transparent protective layer 138 may be formed of a transparent conductive material or a transparent insulating material. The transparent conductive material may include, for example, indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), zinc indium oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), Indium 4 Sn 3 O 12 and zinc magnesium oxide (Zn (1-x) Mg x O, 0≤x≤1) or a conductive polymer. The transparent insulating material may include, for example, at least one of the following: SiO 2 、SiN、TiO 2 , HfO and MgF 2 .

[0044] The second insulating layer 150 may be disposed on the transparent protective layer 138 and the first insulating layer 130. Figure 2 As shown, the second insulating layer 150 may be located on an upper surface of the transparent protective layer 138 , and may continuously extend along side surfaces of the transparent protective layer 138 and the first insulating layer 130 .

[0045] For example, refer to Figure 3A as well as Figure 1 and Figure 2When the transparent protective layer 138 is formed of a transparent insulating material, a first opening OPa and a second opening OPb may be formed, the first opening OPa being an opening that passes through the first insulating layer 130 and the second insulating layer 150 to expose the first conductive type semiconductor layer 115, and the second opening OPb being an opening that passes through the transparent protective layer 138 and the second insulating layer 150 to expose the reflective electrode layer 144. The first opening OPa may expose the first contact region CT1 of the first conductive type semiconductor layer 115, and the second opening OPb may expose the third contact region CT3 of the reflective electrode layer 144. The first opening OPa may be disposed in the recessed region E, and the second opening OPb may be disposed in the mesa region M.

[0046] The first connection electrode 155n may be disposed on the second insulating layer 150 and electrically connected to the first conductive type semiconductor layer 115 by extending through the first opening OPa onto the first contact region CT1 of the first conductive type semiconductor layer 115. The first connection electrode 155n may be in contact with the first contact region CT1 of the first conductive type semiconductor layer 115. In some example embodiments, in order to improve contact resistance characteristics between the first connection electrode 155n and the first contact region CT1 of the first conductive type semiconductor layer 115, a conductive buffer layer may be disposed between the first connection electrode 155n and the first contact region CT1 of the first conductive type semiconductor layer 115.

[0047] The second connection electrode 155p may be disposed on the second insulating layer 150 and electrically connected to the reflective electrode layer 144 by extending through the second opening OPb onto the third contact region CT3 of the reflective electrode layer 144. Therefore, the second connection electrode 155p may be electrically connected to the second conductive type semiconductor layer 125 via the reflective electrode layer 144.

[0048] In another example, refer to Figure 3B as well as Figure 1 and Figure 2 When the transparent protective layer 138 is formed of a transparent conductive material, Figure 3A Unlike the example shown in the figure, a second opening OPb' may be formed through the second insulating layer 150 to expose the third contact region CT3' of the transparent protective layer 138. In other words, the second opening OPb' may pass through the second insulating layer 150 to directly contact the transparent protective layer 138 (i.e., without passing through the transparent protective layer 138). The first opening OPa may be disposed in the recessed region E, and the second opening OPb' may be disposed in the mesa region M.

[0049] Return to reference Figure 2, the first connection electrode 155n may be disposed on the second insulating layer 150 and electrically connected to the first conductive type semiconductor layer 115 by extending through the first opening OPa onto the first contact region CT1 of the first conductive type semiconductor layer 115. The first connection electrode 155n may be in contact with the first contact region CT1 of the first conductive type semiconductor layer 115. In some example embodiments, a conductive buffer pattern may be formed between the first connection electrode 155n and the first contact region CT1 of the first conductive type semiconductor layer 115 so as to improve contact resistance characteristics between the first connection electrode 155n and the first contact region CT1 of the first conductive type semiconductor layer 115.

[0050] The second connection electrode 155p may be disposed on the second insulating layer 150 and electrically connected to the reflective electrode layer 144 by extending through the second opening OPb onto the third contact region CT3 of the reflective electrode layer 144. Therefore, the second connection electrode 155p may be electrically connected to the second conductive type semiconductor layer 125 via the reflective electrode layer 144.

[0051] The first connection electrode 155n and the second connection electrode 155p may be disposed on the second insulating layer 150, formed of the same material, and spaced apart from each other. For example, the first connection electrode 155n and the second connection electrode 155p may be formed of a material including at least one of the following: Al, Au, W, Pt, Si, Ir, Ag, Cu, Ni, Ti, Cr, and alloys thereof. In a plan view, the first connection electrode 155n may be adjacent to the first edge S1, and the second connection electrode 155p may be adjacent to the third edge S3.

[0052] The third insulating layer 160 may include a third opening 160a on the first connection electrode 155n and a fourth opening 160b on the second connection electrode 155p. The third opening 160a may expose the fourth contact region CT4 of the first connection electrode 155n, and the fourth opening 160b may expose the fifth contact region CT5 of the second connection electrode 155p.

[0053] The first electrode pad 165n may be disposed on the fourth contact region CT4 of the first connection electrode 155n, and the second electrode pad 165p may be disposed on the fifth contact region CT5 of the second connection electrode 155p. The first solder column 170n may be disposed on the first electrode pad 165n, and the second solder column 170p may be disposed on the second electrode pad 165p. The first solder column 170n and the second solder column 170p may be formed of a conductive material (e.g., Sn or AuSn).

[0054] The molding part 172 may cover the side surfaces of the first solder pillar 170n and the second solder pillar 170p. The molding part 172 may include a reflective powder such as TiO2 or Al 2 O 3 The upper surface of the molding portion 172 may be lower than upper surfaces of the first and second solder pillars 170n and 170p.

[0055] Figure 4 and Figure 5 2 is a cross-sectional view schematically illustrating a semiconductor light emitting device according to a modified example embodiment. Figure 4 and Figure 5 The semiconductor light emitting device exemplified in Figure 2 , the similar structures of the semiconductor light emitting devices illustrated in FIG. 1 and the differences therebetween will be mainly described.

[0056] refer to Figure 4 ,and Figure 2 Unlike the example shown in FIG. 1 , the reflective electrode layer 144 of the semiconductor light emitting device may be directly disposed on the first insulating layer 130. That is, in the example embodiment, the reflective electrode layer 144 may not be formed. Figure 2 The second transparent electrode layer 142 is shown in FIG.

[0057] refer to Figure 5 ,and Figure 2 Unlike the semiconductor light emitting device shown, the semiconductor light emitting device may further include a covering electrode layer 146 disposed on the reflective electrode layer 144. The covering electrode layer 146 may have a multilayer structure in which Ti and Ni are alternately stacked. The covering electrode layer 146 may have a multilayer structure of, for example, Ti / Ni / Ti / Ni / Ti.

[0058] Figure 6 is a cross-sectional view schematically illustrating a semiconductor light emitting device according to another modified example embodiment.

[0059] refer to Figure 6 The semiconductor light emitting device may include a plurality of light emitting structures 110 disposed on a substrate 105 and separated by an isolation region ISO in which the first conductive type semiconductor layer 115 is removed. In the isolation region ISO, the first insulating layer 130 may contact the front surface 105s1 of the substrate 105.

[0060] The semiconductor light emitting device may further include an interconnection portion 155c disposed on the isolation region ISO and connecting a first connection electrode 155n of a first light emitting structure 110 among the plurality of light emitting structures 110 to a second connection electrode 155p of a second light emitting structure 110 disposed adjacent to the first light emitting structure 110.

[0061] Next, we will refer to Figures 7 to 20A method of manufacturing the semiconductor light emitting device 10 according to example embodiments is described. Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 is a plan view schematically illustrating a method of manufacturing a semiconductor light emitting device 10 according to example embodiments. Figure 8 , Fig.10 , Fig.12 , Fig.14 , Fig.16 , Fig.18 and Fig. 20 are along Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 A cross-sectional view taken along line II'.

[0062] refer to Figure 7 and Figure 8 The light emitting structure 110 may be formed on a substrate 105. The substrate 105 may be made of, for example, sapphire, Si, SiC, MgAl 2 O 4 、MgO、LiAlO 2 、LiGaO 2 The substrate 105 may include a front surface 105s1 and a rear surface 105s2 opposite to the front surface 105s1.

[0063] In some example embodiments, a concavo-convex structure may be formed on the front surface 105s1 of the substrate 105. In some example embodiments, a concavo-convex structure may not be formed on the front surface 105s1 of the substrate 105.

[0064] The light emitting structure 110 may be formed on the front surface 105s1 of the substrate 105. The light emitting structure 110 may be formed in a plurality of layers by a metal organic chemical vapor deposition (MOCVD) process, a hydride vapor phase epitaxy (HVPE) process, a molecular beam epitaxy (MBE) process, etc. For example, the light emitting structure 110 may include a first conductive type semiconductor layer 115, an active layer 120, and a second conductive type semiconductor layer 125 sequentially formed on the front surface 105s1 of the substrate 105. The first conductive type semiconductor layer 115 may have a conductive type different from that of the second conductive type semiconductor layer 125. For example, the first conductive type semiconductor layer 115 may have n-type conductivity, and the second conductive type semiconductor layer 125 may have p-type conductivity. In addition, a first transparent electrode layer 140 may be formed on the light emitting structure 110.

[0065] refer to Fig. 9 and Fig.10 , the first transparent electrode layer 140, the second conductive type semiconductor layer 125, the active layer 120, and a portion of the first conductive type semiconductor layer 115 may be etched using a photolithography and etching process. Therefore, the light emitting structure 110 may include a recessed area E and a mesa area M disposed around the recessed area E ( Fig. 9 ), a portion of the second conductive type semiconductor layer 125, the active layer 120, and the first conductive type semiconductor layer 115 is removed in the recessed region E. The mesa region M may be defined as a region where the second conductive type semiconductor layer 125, the active layer 120, and the first conductive type semiconductor layer 115 are not etched. Compared with the recessed region E, the mesa region M may have a relatively protruding shape ( Fig.10 ). The recessed area E may be referred to as an etching area.

[0066] refer to Fig.11 and Fig.12 , a first insulating layer 130 including a plurality of through holes PD may be formed on the light emitting structure 110. The plurality of through holes PD of the first insulating layer 130 may partially expose the first transparent electrode layer 140. The plurality of through holes PD may be provided in the mesa region M.

[0067] refer to Fig.13 and Fig.14 , the second transparent electrode layer 142 and the reflective electrode layer 144 may be formed on the first insulating layer 130. The second transparent electrode layer 142 and the reflective electrode layer 144 may be formed in the mesa region M and on a portion of the first insulating layer 130.

[0068] refer to Fig.15 and Fig.16 , a transparent protective layer 138 may be formed on the reflective electrode layer 144. The transparent protective layer 138 may cover the upper surface and the side surface of the reflective electrode layer 144 and the side surface of the second transparent electrode layer 142. The transparent protective layer 138 may partially cover the first insulating layer 130 adjacent to the reflective electrode layer 144. The transparent protective layer 138 may be formed after forming a photoresist pattern, for example, in a physical deposition process (e.g., sputtering), the photoresist pattern exposing a region where the transparent protective layer 138 is formed.

[0069] refer to Fig.17 and Fig.18, a second insulating layer 150 may be formed on the first insulating layer 130 and the transparent protective layer 138. A first opening OPa and a second opening OPb may be formed, the first opening OPa passing through the first insulating layer 130 and the second insulating layer 150 to partially expose the first conductive type semiconductor layer 115 in the recessed area E, and the second opening OPb passing through the transparent protective layer 138 and the second insulating layer 150 to partially expose the reflective electrode layer 144 in the mesa area M. The surface of the first conductive type semiconductor layer 115 exposed by the first opening OPa may be referred to as a first contact region CT1, and the surface of the reflective electrode layer 144 exposed by the second opening OPb may be referred to as a third contact region CT3.

[0070] refer to Fig.19 and Fig. 20 , the first connection electrode 155n and the second connection electrode 155p may be formed on the substrate 105 including the second insulating layer 150. The formation of the first connection electrode 155n and the second connection electrode 155p may include forming a conductive material layer on the substrate 105 including the second insulating layer 150, and partially etching the conductive material layer using a photolithography and etching process. Since the first connection electrode 155n and the second connection electrode 155p are formed simultaneously in a single process, they are formed of the same material. The first connection electrode 155n and the second connection electrode 155p may have the same thickness.

[0071] The first connection electrode 155n may be electrically connected to the first contact region CT1 of the first conductive type semiconductor layer 115. The second connection electrode 155p may be electrically connected to the third contact region CT3 of the reflective electrode layer 144.

[0072] Reference again Figure 1 and Figure 2 , a third insulating layer 160 including a third opening 160a and a fourth opening 160b may be formed on the substrate 105 including the first connection electrode 155n and the second connection electrode 155p. The third opening 160a of the third insulating layer 160 may expose a portion of the first connection electrode 155n, and the fourth opening 160b of the third insulating layer 160 may expose a portion of the second connection electrode 155p.

[0073] The portion of the first connection electrode 155n exposed by the third opening 160a of the third insulating layer 160 may be referred to as a fourth contact region CT4, and the portion of the second connection electrode 155p exposed by the fourth opening 160b of the third insulating layer 160 may be referred to as a fifth contact region CT5. The first electrode pad 165n and the second electrode pad 165p may be formed on the substrate 105 including the third insulating layer 160. The first electrode pad 165n may be formed on the fourth contact region CT4 of the first connection electrode 155n, and the second electrode pad 165p may be formed on the fifth contact region CT5 of the second connection electrode 155p. The first electrode pad 165n and the second electrode pad 165p may be an under bump metallurgy (UBM) layer. In some example embodiments, the number and arrangement of the first electrode pad 165n and the second electrode pad 165p may be modified differently.

[0074] The first solder pillar 170n and the second solder pillar 170p may be formed on the substrate 105 including the first and second electrode pads 165n and 165p. The first solder pillar 170n may be formed on the first electrode pad 165n, and the second solder pillar 170p may be formed on the second electrode pad 165p.

[0075] A molding portion 172 may be formed to cover the side surfaces of the first solder pillar 170n and the second solder pillar 170p. The molding portion 172 may include a reflective powder such as TiO 2 or Al 2 O 3 .

[0076] The semiconductor light emitting device 10 as described above can be commercialized in a packaged form. Fig.21 An example of the semiconductor light emitting device 10 applied to a package is described. Fig.21 is a cross-sectional view schematically illustrating an example of a package including a semiconductor light emitting device according to an example embodiment.

[0077] refer to Fig.21 , the semiconductor light emitting device package 1000 may include a semiconductor light emitting device 1001 as a light source, a package body 1002, a pair of lead frames 1010, and a sealant 1005. Here, the semiconductor light emitting device 1001 may be Figures 1 to 6 The semiconductor light emitting device 10 is shown in FIG. 1 , and thus a detailed description thereof will be omitted.

[0078] The semiconductor light emitting device 1001 may be mounted on a lead frame 1010 and electrically connected to the lead frame 1010. The pair of lead frames 1010 may include a first lead frame 1012 and a second lead frame 1014. Figure 2 and Fig.21, the semiconductor light emitting device 1001 can be Figure 2 The first solder pillar 170n and the second solder pillar 170p are connected to the first lead frame 1012 and the second lead frame 1014.

[0079] The package body 1002 may have a reflective cup to enhance light reflection efficiency and light extraction efficiency. A sealant 1005 formed of a light-transmitting material may be formed in the reflective cup to encapsulate the semiconductor light emitting device 1001. The sealant 1005 may include a wavelength conversion material, such as a fluorescent material or quantum dots.

[0080] By summarizing and reviewing, as described above, a semiconductor light-emitting device with improved luminous flux and reliability can be provided. That is, according to an embodiment, a semiconductor light-emitting device can include a p-type omnidirectional reflector (ODR) having a structure in which a thin transparent conductive oxide adhesion layer is inserted between a reflective metal (e.g., silver) and a dielectric material as an adhesion layer, with a transparent conductive / insulating material covering the upper and side surfaces of the reflective metal. Therefore, reflectivity and luminous efficiency are increased, while peeling of the reflective metal or its migration can be suppressed.

[0081] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some cases, as will be apparent to one of ordinary skill in the art at the time of filing this application, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise specifically noted. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A semiconductor light emitting device, include: A light emitting structure comprising a first conductive type semiconductor layer, an active layer and a second conductive type semiconductor layer, the light emitting structure comprising: a recessed area and a mesa area adjacent to the recessed area, wherein the second conductive type semiconductor layer is etched in the recessed area, the active layer is etched and a portion of the first conductive type semiconductor layer is etched; a first transparent electrode layer, which is located on the second conductive type semiconductor layer; a first insulating layer located on the first transparent electrode layer and the second conductive type semiconductor layer in the recessed area, the first insulating layer comprising a plurality of through holes in the mesa area; a reflective electrode layer, which is located on the first insulating layer and connected to the first transparent electrode layer through the plurality of through holes; a transparent protective layer, which covers the upper surface and the side surface of the reflective electrode layer, and the transparent protective layer is located on a portion of the first insulating layer; a second insulating layer covering the upper surface and side surfaces of the transparent protective layer; a first connection electrode disposed on the second insulating layer and passing through a first opening disposed in the recessed area and connected to the first conductive type semiconductor layer, the first opening passing through the first insulating layer and the second insulating layer; and A second connection electrode is disposed on the second insulating layer, passes through a second opening disposed in the mesa region, and is connected to the transparent protection layer or the reflective electrode layer, the second opening passing through the second insulating layer.

2. The semiconductor light emitting device according to claim 1, in, The transparent protective layer comprises: covering an upper portion of an upper surface of the reflective electrode layer, the upper portion having a convex surface; and A side portion covering a side surface of the reflective electrode layer has an inclined surface.

3. The semiconductor light emitting device according to claim 1, in, The transparent protection layer includes a transparent insulating material.

4. The semiconductor light emitting device according to claim 1, in, The transparent protection layer includes a transparent conductive material.

5. The semiconductor light emitting device according to claim 1, in, The first insulating layer includes SiO 2 、SiN、TiO 2 , HfO and MgF 2 At least one of .

6. The semiconductor light emitting device according to claim 1, in, The first insulating layer has a distributed Bragg reflector structure in which insulating layers having different refractive indices are alternately stacked.

7. The semiconductor light emitting device according to claim 1, in, The reflective electrode layer includes Ag, Cr, Ni, Ti, Al, Rh, Ru or a combination thereof. 8 . The semiconductor light emitting device of claim 1 , further comprising a second transparent electrode layer between the first insulating layer and the reflective electrode layer.

9. The semiconductor light emitting device according to claim 8, in, The second transparent electrode layer contacts the first transparent electrode layer through the plurality of through holes. 10 . The semiconductor light emitting device according to claim 1 , further comprising a covering electrode layer between the reflective electrode layer and the transparent protective layer.

11. A semiconductor light emitting device, include: A light emitting structure having a stacked structure of a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer, the light emitting structure comprising: a recessed region in which the second conductive type semiconductor layer is etched, the active layer is etched, and a portion of the first conductive type semiconductor layer is etched, and a mesa region adjacent to the recessed region; a first transparent electrode layer, which is located on the second conductive type semiconductor layer; a first insulating layer covering the first transparent electrode layer and the second conductive type semiconductor layer in the recessed area, the first insulating layer comprising a plurality of through holes in the mesa area; a second transparent electrode layer, which is located on the first insulating layer and contacts the first transparent electrode layer through the plurality of through holes; a reflective electrode layer, which is located on the second transparent electrode layer; a transparent protective layer, which covers the upper surface and the side surface of the reflective electrode layer, and the transparent protective layer is located on a portion of the first insulating layer; a second insulating layer covering the upper surface and side surfaces of the transparent protective layer; a first connection electrode disposed on the second insulating layer and passing through a first opening disposed in the recessed area and connected to the first conductive type semiconductor layer, the first opening passing through the first insulating layer and the second insulating layer; and A second connecting electrode is disposed on the second insulating layer and passes through a second opening disposed in the mesa region and is connected to the transparent protective layer or the reflective electrode layer, wherein the second opening passes through the second insulating layer.

12. The semiconductor light emitting device according to claim 11, in, The transparent protective layer comprises: an upper portion covering the upper surface of the reflective electrode layer, the upper portion having a convex surface, and A side portion covering a side surface of the reflective electrode layer has an inclined surface.

13. The semiconductor light emitting device according to claim 11, in, The transparent protective layer includes insulating material.

14. The semiconductor light emitting device according to claim 11, in, The refractive index of the first insulating layer is lower than the refractive index of the second conductive type semiconductor layer. 15 . The semiconductor light emitting device of claim 11 , further comprising a covering electrode layer between the reflective electrode layer and the transparent protective layer.

16. A semiconductor light emitting device, include: substrate; At least one light emitting structure, comprising a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer sequentially stacked on the substrate, the light emitting structure comprising: a recessed region and a mesa region adjacent to the recessed region, wherein the second conductive type semiconductor layer is etched in the recessed region, the active layer is etched, and a portion of the first conductive type semiconductor layer is etched; a first transparent electrode layer connected to the second conductive type semiconductor layer; a first insulating layer partially covering the first transparent electrode layer and the second conductive type semiconductor layer in the recessed area; a second transparent electrode layer passing through the first insulating layer and connected to the first transparent electrode layer; a reflective electrode layer connected to the second transparent electrode layer; a transparent protective layer, which covers the upper surface and the side surface of the reflective electrode layer, and the transparent protective layer is located on a portion of the first insulating layer; a second insulating layer covering the upper surface and side surfaces of the transparent protective layer; a first connection electrode disposed on the second insulating layer, passing through the first insulating layer and the second insulating layer on the recessed area and the active layer and the second conductive type semiconductor layer in the recessed area, and connected to the first conductive type semiconductor layer; and A second connecting electrode is disposed on the second insulating layer, passes through the transparent protective layer on the mesa region and is connected to the reflective electrode layer.

17. The semiconductor light emitting device according to claim 16, in, The at least one light emitting structure includes a plurality of light emitting structures on the substrate and electrically connected in series, the plurality of light emitting structures being separated by an isolation region where the first conductive type semiconductor layer is removed.

18. The semiconductor light emitting device according to claim 17, further comprising: include: a first connection electrode connected to the first conductive type semiconductor layer of a first light emitting structure among the plurality of light emitting structures; a second connection electrode connected to the second conductive type semiconductor layer of a second light emitting structure among the plurality of light emitting structures; as well as An interconnection portion is located on the isolation region and connects the first connection electrode and the second connection electrode.

19. The semiconductor light emitting device according to claim 16, further comprising: include: a first electrode pad and a second electrode pad connected to the first connection electrode and the second connection electrode, respectively; A first solder column and a second solder column connected to the first electrode pad and the second electrode pad, respectively; and A molding portion covers a side surface of the first solder pillar and a side surface of the second solder pillar.

20. The semiconductor light emitting device according to claim 19, in, The molded portion includes reflective powder.

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