Semiconductor light emitting device and display device

Abstract

A semiconductor light emitting device and a display device are provided. The semiconductor light emitting device comprises: a light emitting structure having a rod shape, the light emitting structure having a first surface and a second surface opposite to each other and a side surface connected between the first surface and the second surface, the light emitting structure comprising a first conductive type semiconductor providing the first surface, an active layer, and a second conductive type semiconductor; a first electrode layer located on a first region of the first surface of the light emitting structure and connected to the first conductive type semiconductor, the level of the first region being vertically offset relative to the level of a second region adjacent thereto; and a second electrode layer connected to the second conductive type semiconductor.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] Korean Patent Application No. 10-2019-0075013, entitled “Semiconductor Light Emitting Device and Display Apparatus,” filed on June 24, 2019 in the Korean Intellectual Property Office is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments relate to a semiconductor light emitting device and a display apparatus. Background Art

[0004] Semiconductor light emitting diodes (LEDs) are used not only as light sources for lighting devices but also as light sources for various electronic products. In detail, LEDs are widely used as light sources for various display devices such as TVs, mobile phones, PCs, notebook PCs, PDAs, etc. Summary of the invention

[0005] An embodiment relates to a semiconductor light emitting device, comprising: a light emitting structure having a rod shape, the light emitting structure having a first surface and a second surface opposite to each other and a side surface connected between the first surface and the second surface, and the light emitting structure including a first conductive type semiconductor providing a first surface, an active layer, and a second conductive type semiconductor; a first electrode layer, which is located on a first area of ​​the first surface of the light emitting structure and connected to the first conductive type semiconductor, and the horizontal height of the first area is vertically offset relative to the horizontal height of a second area adjacent to the first conductive type semiconductor; and a second electrode layer, which is connected to the second conductive type semiconductor.

[0006] An embodiment also relates to a semiconductor light-emitting device, comprising: a light-emitting structure having a rod shape, the light-emitting structure having a first surface and a second surface opposite to each other and a side surface connected between the first surface and the second surface, the light-emitting structure comprising a first conductive type semiconductor layer and a second conductive type semiconductor layer providing the first surface and the second surface, respectively, and an active layer arranged between the first conductive type semiconductor layer and the second conductive type semiconductor layer; a first electrode layer, which is connected to the first conductive type semiconductor layer and is arranged on a first area on the first surface of the light-emitting structure, and the horizontal height of the first area is vertically offset relative to the horizontal height of a second area adjacent to it; and a second electrode layer, which is located on the second surface of the light-emitting structure and connected to the second conductive type semiconductor layer.

[0007] An embodiment also relates to a semiconductor light-emitting device, comprising: a first conductive type semiconductor rod having a first surface and a second surface opposite to each other and a side surface connected between the first surface and the second surface, the first conductive type semiconductor rod comprising a first portion adjacent to the first surface and a second portion adjacent to the second surface; an active layer and a second conductive type semiconductor layer sequentially arranged on the side surface of the second portion of the first conductive type semiconductor rod; a first electrode layer, which is connected to the first conductive type semiconductor rod and is arranged in a first region of the first surface of the first conductive type semiconductor rod, the horizontal height of the first region being vertically offset relative to the horizontal height of the second region adjacent to the first conductive type semiconductor rod; and a second electrode layer, which is arranged on the second conductive type semiconductor layer.

[0008] An embodiment also relates to a display device, comprising: a plurality of pixels; a first electrode portion and a second electrode portion arranged in a pixel among the plurality of pixels, the first electrode portion being spaced apart from the second electrode portion, and a semiconductor light emitting device according to the embodiment being arranged between them, so that the first electrode layer of the semiconductor light emitting device is connected to the first electrode portion, and the second electrode layer of the semiconductor light emitting device is connected to the second electrode portion. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0010] Figure 1 shows a side cross-sectional view of a semiconductor light emitting device according to example embodiments;

[0011] Figure 2A Show Figure 1 a plan view (of a first surface) of a semiconductor light emitting device, Figure 2B Shown along Figure 1 A cross-sectional view of a semiconductor light emitting device taken along line II';

[0012] Figure 3 A plan view (of a first surface) of a semiconductor light emitting device according to example embodiments is shown.

[0013] Figure 4 A side cross-sectional view of a semiconductor light emitting device according to example embodiments is shown.

[0014] FIG. 5A to FIG. 5I cross-sectional views showing stages in a method of manufacturing a semiconductor light emitting device according to example embodiments;

[0015] Figure 6 Show Figure 5B a plan view of the arrangement of the pattern shown;

[0016] Figure 7 Show Figure 5E A plan view of the process result (after etching to form nanorods) is shown;

[0017] Figure 8 Show Fig. 5F A plan view of the process result (after wet etching to remove the damaged layer) is shown;

[0018] Fig. 9 shows a side cross-sectional view of a semiconductor light emitting device according to example embodiments;

[0019] Fig. 10A Show Fig. 9 A plan view (of the first surface) of the semiconductor light emitting device shown, Fig. 10B and Fig. 10C Shown along Fig. 9 A cross-sectional view taken along line II1-II1' and line II2-II2' of the semiconductor light emitting device shown;

[0020] Fig.11 and Fig.12 shows a side cross-sectional view of a semiconductor light emitting device according to various embodiments;

[0021] FIG. 13A to FIG. 13E cross-sectional views showing stages in a method of manufacturing a semiconductor light emitting device according to example embodiments;

[0022] FIG. 14A to FIG. 14F cross-sectional views showing stages in a method of manufacturing a semiconductor light emitting device according to example embodiments;

[0023] Fig.15 Show Fig. 13C A plan view of the process result (after forming the nanopore) is shown;

[0024] Fig.16 Show Fig.14A A plan view of the process result (after regrowth) is shown;

[0025] Fig.17 shows a side cross-sectional view of a display device according to an example embodiment;

[0026] Fig.18 Show Fig.17 A perspective view of one pixel of a display device is shown. DETAILED DESCRIPTION

[0027] Figure 1 is a side cross-sectional view showing a semiconductor light emitting device according to example embodiments, Figure 2A yes Figure 1 a plan view of a semiconductor light emitting device (showing a first surface), Figure 2B is along Figure 1A cross-sectional view of the light-emitting device taken along line II'.

[0028] Reference Figure 1 , a semiconductor light emitting device 100 according to example embodiments may include a light emitting structure 120 including a first conductive type semiconductor 122 , an active layer 125 , and a second conductive type semiconductor 127 .

[0029] According to the present example embodiment, the light emitting structure 120 has a bar shape having a first surface 120A, a second surface 120B opposite to the first surface 120A, and a side surface 120C connected between the first surface 120A and the second surface 120B.

[0030] At the first surface 120A, the first conductive type semiconductor 122 may have a first region A1 and a second region A2. In the first region A1, the first surface 120A may be flat, but considering both the first region A1 and the second region A2, the first surface 120A may be a non-flat surface overall. The first conductive type semiconductor 122 may have a protruding structure P in the second region A2 (e.g., Figure 1 protrudes downward in the second area A2), so that in the second area A2, the first conductive type semiconductor 122 extends beyond the surface in the first area A1 and is vertically offset relative to the surface in the first area A1, and the level of the first area A1 can be lower than the level of the second area A2.

[0031] The ohmic contact layer 114 may be connected to the first conductive type semiconductor 122 and may function as a first electrode layer. The ohmic contact layer 114 may be disposed in the first region A1 and adjacent to the second region A2. The second electrode layer 134 may be connected to the second conductive type semiconductor 127.

[0032] As described above, the ohmic contact layer 114 in the present exemplary embodiment may be disposed on the first conductive type semiconductor 122 at the first surface 120A of the light emitting structure 120. Figure 1 As shown, the protruding structure P located in the second area A2 of the first surface 120A may be relative to Figure 1 The first surface 120A may protrude in the vertical direction to be higher than or protrude beyond the ohmic contact layer 114 (i.e., beyond the first electrode layer). As described below, the first area A1 of the first surface 120A may correspond to a crystal plane obtained when the nanorod-type light emitting structure 120 is separated from the substrate during manufacturing, and the second area A2 of the first surface 120A may be a cleavage plane of the first conductive type semiconductor 122.

[0033] like Figure 2AAs shown, at the first surface 120A of the light-emitting structure 120, the first region A1 can be set to surround (e.g., completely enclose) the second region A2. Thus, since the second region A2 is surrounded by the already separated first region A1, the second region A2 can be easily separated even by thermal or mechanical shock.

[0034] Referring again to Figure 1 , the first-conductivity-type semiconductor 122, the second-conductivity-type semiconductor 127, and the active layer 125 can be nitride semiconductors, and the light-emitting structure 120 can be a nitride light-emitting structure. The first-conductivity-type semiconductor 122 and the second-conductivity-type semiconductor 127 can also be respectively referred to as "the first-conductivity-type semiconductor layer and the second-conductivity-type semiconductor layer".

[0035] The first-conductivity-type semiconductor 122 can be a nitride semiconductor layer satisfying n-type In x Al y Ga 1-x-y N (0 ≤ x < 1, 0 ≤ y < 1, 0 ≤ x + y < 1), and the n-type impurity can be silicon (Si). For example, the first-conductivity-type semiconductor 122 can include an n-type GaN layer.

[0036] The second-conductivity-type semiconductor 127 can be a nitride semiconductor layer satisfying p-type In x Al y Ga 1-x-y N (0 ≤ x < 1, 0 ≤ y < 1, 0 ≤ x + y < 1), and the p-type impurity can be magnesium (Mg). In an exemplary embodiment, the second-conductivity-type semiconductor 127 can be implemented as a single-layer structure, but in another embodiment, the second-conductivity-type semiconductor 127 can have a multi-layer structure with different compositions.

[0037] The active layer 125 can have a multi-quantum well (MQW) structure in which quantum well layers and quantum barrier layers are alternately stacked. For example, the quantum well layers and the quantum barrier layers can be In x Al y Ga 1-x-y N (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ x + y ≤ 1) layers with different compositions. In a specific example, the quantum well layer can be In x Ga 1-x N (0 < x ≤ 1) layer, and the quantum barrier layer can be a GaN or AlGaN layer. The thickness of each of the quantum well layers and the quantum barrier layers can be in the range of 1 nm to 50 nm. In another exemplary embodiment, the structure of the active layer 125 can be a single quantum well structure.

[0038] As Figure 2AAs shown, the ohmic contact layer 114 as the first electrode layer positioned in the first area A1 may have a ring shape. For example, the ring shape of the ohmic contact layer 114 may be a donut shape.

[0039] In the present exemplary embodiment, the cross-sectional width of the light emitting structure 120 may be smaller than the outer width of the ohmic contact layer 114, which may be understood as the cross-sectional width of the light emitting structure 120 during dry etching (see Figure 5E ) to form the nanorod-shaped light emitting structure 120 and then wet-etching (see Fig. 5F ) is the result of additional etching to remove surface damaged areas.

[0040] Reference Figure 2B , the nanorod-shaped cross section of the light emitting structure 120 (a cross section taken along line II') may have a hexagonal structure. For example, the light emitting structure 120 may be formed of a nitride semiconductor and thus may have a hexagonal columnar structure. The second surface 120B of the light emitting structure 120 may be positioned inside the outer edge line of the donut-shaped ohmic contact layer 114.

[0041] In another example embodiment, Figure 3 As shown, the ohmic contact layer 114 may also have a hexagonal ring structure. The ohmic contact layer 114 may also be disposed along the contour of the first surface 120A of the light emitting structure 120. In a specific example, the hexagonal cross section of the light emitting structure 120 may be smaller than the outer hexagonal area of ​​the ohmic contact layer 114.

[0042] The shape of the ohmic contact layer 114 may have various other patterns. Similarly, although the light emitting structure 120 in the present exemplary embodiment is shown as having a hexagonal columnar structure, according to the etching process (see FIG. 1 ) of forming the semiconductor crystal structure and / or nanorods constituting the light emitting structure 120. Figure 5E ) and post-processing (see Fig. 5F ), the light emitting structure 120 may also have a cylindrical shape or various other shapes.

[0043] The first electrode layer in this example embodiment may include an ohmic contact layer 114 connected to the first conductive type semiconductor 122. For example, the ohmic contact layer 114 may include at least one of silver (Ag), aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu), gold (Au), palladium (Pd), platinum (Pt), tin (Sn), tungsten (W), rhodium (Rh), iridium (Ir), ruthenium (Ru), magnesium (Mg), zinc (Zn), and alloy materials thereof. In example embodiments, the ohmic contact layer 114 may include W or WSi.

[0044] The second electrode layer 134 may be disposed at the second surface 120B of the light emitting structure 120 to be connected to the second conductive type semiconductor 127. The second electrode layer 134 may be disposed almost entirely on the second surface 120B of the light emitting structure 120. For example, the second electrode layer 134 may include Ag, Ni, Al, Cr, Rh, Pd, Ir, Ru, Mg, Zn, Pt, or Au, and may be adopted in a single layer or a structure of two or more layers. In an example embodiment, the second electrode layer 134 may be a transparent electrode formed of a transparent conductive oxide or a transparent conductive nitride, or may include graphene. For example, the second electrode layer 134 may include a material selected from indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), indium zinc 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 Zn (1-x) Mg x O (zinc magnesium oxide, 0≤x≤1).

[0045] The semiconductor light emitting device 100 according to the present example embodiment may include a passivation layer 145 disposed on the side surface 120C of the light emitting structure 120. For example, the passivation layer 145 may include a silicon such as SiO 2 、SiN、TiO 2 In another example, the passivation layer 145 may include a low conductivity semiconductor material such as AlGaN, undoped GaN, Mg-doped AlN, Mg-doped AlGaN, and Mg-doped GaN.

[0046] The semiconductor light emitting device 100 according to the present example embodiment may include an ohmic contact layer 114 and a second electrode layer 134 serving as a first electrode layer, while having a nanorod structure. The ohmic contact layer 114 may be provided before the growth of the light emitting structure 120. Therefore, the ohmic contact layer 114 may have a form embedded in the first surface 120A of the light emitting structure 120 (for example, in the first conductive type semiconductor 122). The ohmic contact layer 114 may be formed in a first region A1 of the first surface 120A of the light emitting structure 120, and the second region A2 may be a cleavage plane obtained when the semiconductor light emitting device 100 is separated from the substrate. Although slightly different depending on the crystal plane split when separated from the substrate, the second region A2 may have a relative Figure 1 The second area A2 may have a structure that protrudes higher or more than the first area A1 in a vertical direction. In addition, the second area A2 may have a structure surrounded by the first area A1, so that separation may easily occur in the second area A2.

[0047] Figure 4is a side cross-sectional view illustrating a semiconductor light emitting device according to example embodiments.

[0048] Reference Figure 4 , except that the protrusion structure P′ has a different shape and the first electrode layer 110 has a multi-layer structure, the semiconductor light emitting device 100′ according to the example embodiment may be similar to Figures 1 to 3 The semiconductor light emitting device 100 is shown. Unless otherwise specified, the components of this example embodiment may refer to Figures 1 to 3 The description of the same or similar components of the semiconductor light emitting device 100 shown herein should be understood.

[0049] The semiconductor light emitting device 100' according to the present exemplary embodiment has a protruding structure P' protruding at the first surface 120A of the light emitting structure 120. Figures 1 to 3 As in the previous embodiment, the first area A1 (where the first electrode layer 110 is disposed) may have a level that is higher or vertically offset relative to the second area A2.

[0050] like Figure 4 As shown, unlike the previous embodiment, the protruding structure P' may be formed to partially expose the inner surface of the first electrode layer 110. The protruding structure P' may be a surface obtained by separating the light emitting structure 120 from the substrate by concentrating stress on a portion surrounded by the first electrode layer 110, and thus may be divided into various shapes due to the presence of existing cracks (e.g., crystal defects), etc. For example, as in the present exemplary embodiment, the first surface 120A may have an inclined surface in the second area A2.

[0051] The first electrode layer 110 may be embedded in the first conductive type semiconductor 122 in the first surface 120A of the light emitting structure 120. The first electrode layer 110 in the present exemplary embodiment may have a multi-layer structure. The first electrode layer 110 may include an ohmic contact layer 114 connected to the first conductive type semiconductor 122 and a metal nitride layer 112 disposed on the ohmic contact layer 114.

[0052] For example, the ohmic contact layer 114 may include at least one of Ag, Al, Ni, Cr, Cu, Au, Pd, Pt, Sn, W, Rh, Ir, Ru, Mg, Zn, and alloy materials thereof. In example embodiments, the ohmic contact layer 114 may include W or WSi.

[0053] The metal nitride layer 112 may include, for example, TiN, TaN, or WN as a conductive layer. The metal nitride layer 112 may be understood as a layer formed as a metal layer (for example, a titanium (Ti), tantalum (Ta), or W layer) during the growth of the light emitting structure 120 (see Figure 5B) reacts with the nitrogen component of the substrate. In example embodiments, only the ohmic contact layer 114 may be used as the first electrode layer (see Figure 1 ) is retained to selectively remove the metal nitride layer 112.

[0054] FIG. 5A to FIG. 5I are cross-sectional views illustrating main processes of a method of manufacturing a semiconductor light emitting device according to example embodiments.

[0055] Reference Figure 5A , the nitride single crystal substrate 101 may be used as a growth substrate containing a nitrogen component. For example, the nitride single crystal substrate may include In x Al y Ga 1-x-y A nitride single crystal substrate 101 may be a GaN substrate.

[0056] Metal layer 112' and a material layer for ohmic contact layer 114 may be sequentially formed on nitride single crystal substrate 101. Metal layer 112' and a material layer for ohmic contact layer 114 may be deposited on nitride single crystal substrate 101 using, for example, chemical vapor deposition (CVD) or sputtering.

[0057] The metal layer 112' may include a metal capable of reacting with the nitrogen component of the nitride single crystal substrate 101 under the single crystal growth conditions for the light emitting structure to form a metal nitride. For example, the metal layer 112' may include Ta, Ti or W. The metal layer 112' may be used to form the metal nitride layer 112 described above.

[0058] The ohmic contact layer 114 may be formed using an electrode material capable of forming an ohmic contact with the first conductive type semiconductor 122 of the light emitting structure 120. For example, the ohmic contact layer 114 may include at least one of Ag, Al, Ni, Cr, Cu, Au, Pd, Pt, Sn, W, Rh, Ir, Ru, Mg, Zn, and alloy materials thereof. In example embodiments, the ohmic contact layer 114 may include W or WSi.

[0059] Reference Figure 5B , the predetermined pattern PA may be formed by patterning the metal layer 112 ′ and the material for the ohmic contact layer 114 . Figure 6 It is shown Figure 5B A plan view of the arrangement of pattern PA is shown.

[0060] Each pattern PA may have a ring shape surrounding an area. Figure 6As shown, each pattern PA may have a circular ring shape. Each pattern PA may define an area of ​​the first electrode layer of the light emitting structure of the nanorod structure. For example, each pattern PA may define Figure 2A The first region A1 of the first electrode layer is to be formed on the first surface 120A of the final light emitting structure 120 shown.

[0061] The area surrounded by each pattern PA can be obtained during the etching process of the nanorods (see Figure 5E ) and can be used as a temporary support region for the light emitting structure after separation of the light emitting structure from the substrate (see Fig.5I ) is a separation area that is split due to brittleness. Therefore, the shape of each pattern PA can be a completely surrounded ring shape, or can be a shape formed by a pattern of another shape (for example, a semicircular shape) that is only partially surrounded or occupies a part, and the remaining area is used as a temporary support area and a separation area.

[0062] Reference Figure 5C , a first conductive type semiconductor 122 , an active layer 125 , and a second conductive type semiconductor 127 are sequentially formed on the nitride single crystal substrate 101 in which the ring pattern PA is formed.

[0063] A semiconductor stack 120" including a first conductive type semiconductor 122, an active layer 125, and a second conductive type semiconductor 127 may be set as a light emitting structure 120 in a subsequent process. The first conductive type semiconductor 122, the active layer 125, and the second conductive type semiconductor 127 may be formed of nitride single crystals as described above. For example, the semiconductor stack 120" may be formed by a metal organic chemical vapor deposition (MOCVD) process.

[0064] The semiconductor stack 120" may be formed using lateral overgrowth (eg, epitaxial, lateral overgrowth (ELOG)) to cover the pattern PA. The merging process (eg, growth time) and the resulting defect location may be appropriately set by appropriately selecting the width and / or location of the pattern PA.

[0065] The growth process may be performed at a high temperature (e.g., 800° C. or higher). Therefore, nitrogen in a region of the nitride single crystal substrate 101 adjacent to the metal layer 112′ may migrate toward the metal layer 112′ to react with the metal layer 112′, thereby forming a metal nitride layer 112 in the growth process. For example, the metal nitride layer 112 may include TiN, TaN, or WN. As a result of this reaction, vacancies due to nitrogen migration may be generated in a region of the nitride single crystal substrate 101 adjacent to the metal layer 112′, and a metal component (e.g., gallium) left in the high temperature process may melt to form a void region V0. The void region V0 may be formed by a pattern region in contact with the metal layer (or metal nitride layer 112), and may facilitate subsequent processes (see Fig.5I ) in the separation of the light emitting structure 120.

[0066] Reference Figure 5D , a second electrode layer 134 may be formed on the semiconductor stack 120 ″, and a mask pattern MP may be formed on the second electrode layer 134 .

[0067] A second electrode layer 134 may be deposited on the semiconductor stack 120″ to connect it to the second conductive type semiconductor 127. For example, the second electrode layer 134 may include Ag, Ni, Al, Cr, Rh, Pd, Ir, Ru, Mg, Zn, Pt, or Au, and may be adopted in a single layer or a two-layer or more layer structure. In the present example embodiment, the second electrode layer 134 may also include a transparent electrode layer such as a transparent conductive oxide layer or a transparent conductive nitride layer. For example, the second electrode layer 134 may be selected from 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 Zn (1-x) Mg x At least one of the O (magnesium zinc oxide, 0≤x≤1) layers. Next, a mask pattern MP for forming a light emitting structure may be formed on the second electrode layer 134 .

[0068] Reference Figure 5E , a preliminary light emitting structure 120 ′ having a nanorod structure may be formed by etching the semiconductor stack 120 ″. Figure 7 It is shown Figure 5E A plan view of the process result (after nanorod etching) is shown.

[0069] A preliminary light emitting structure 120' having a nanorod structure may be formed from the semiconductor stack 120" by using an etching process using the mask pattern MP. For example, as this etching process, a dry etching process such as an inductively coupled plasma reactive ion etching (ICE-RIE) plasma etching process may be used.

[0070] For example, the mask pattern MP provided in the above process may be a circular pattern. As in the present exemplary embodiment, when performing the etching process (see Fig. 5F ) to remove the surface damage area in the subsequent process, the mask pattern MP may have a size slightly larger than the cross-sectional area of ​​the final light emitting structure 120 (or the outline size of the pattern PA). After this process, as Figure 5E and Figure 7 As shown, the preliminary light emitting structure 120' corresponding to the mask pattern MP may be formed to have a substantially cylindrical structure. The preliminary light emitting structure 120' of a cylindrical structure may be set to have an area larger (larger by a gap Ga) than the area of ​​the outer edge of the pattern PA disposed thereunder. The gap Ga may be set in consideration of the portion to be removed in a subsequent etching process to remove a surface damaged area. The preliminary light emitting structure 120' may be further removed in a subsequent etching process, and therefore, in addition to the connection portion C1 surrounded by the pattern PA, the preliminary light emitting structure 120' may be fixed to the nitride single crystal substrate 101 by a peripheral connection portion C2 located on the periphery.

[0071] Reference Fig. 5F , the damaged surface of the preliminary light emitting structure 120 ′ with a nanorod structure may be removed to form a light emitting structure 120 with a predetermined nanorod structure. Figure 8 It is shown Fig. 5F A plan view of the process result (after wet etching) is shown.

[0072] Removal of the damaged surface in the previous etching process can be performed by, for example, wet etching. For example, KOH and / or phosphoric acid can be used for wet etching. In this process, the side surface of the preliminary light emitting structure 120' having a cylindrical structure has a stable crystal surface (e.g., M-plane) in the wet etching process, and thus can be formed into a light emitting structure 120 having a hexagonal columnar structure. In a subsequent etching process, the peripheral connection portion C2 located on the lower end portion of the light emitting structure 120' is additionally removed, and thus the light emitting structure 120 may have a separation region V1 obtained when a void region V0 is formed by expansion along the outer periphery of the lower end of the light emitting structure 120. In this etching process, the metal nitride layer 112 may be used as a protective layer for the ohmic contact layer 114.

[0073] Reference Figure 5G , a passivation layer 145 may be formed on the surface of the light emitting structure 120 having the nanorod structure.

[0074] A passivation layer 145 may be deposited on the surface of the light emitting structure 120. As in the present exemplary embodiment, the passivation layer 145 may be formed on the upper surface of the light emitting structure 120 and the upper surface of the nitride single crystal substrate 101 between the light emitting structures 120, and on the side surface of the light emitting structure 120. Portions of the passivation layer 145 located on the upper surface of the light emitting structure 120 and the upper surface of the nitride single crystal substrate 101 between the light emitting structures 120 may be removed in a subsequent process. For example, the passivation layer 145 may include a material such as SiO 2 、SiN、TiO 2 and / or an insulating material of AlN. In another example, the passivation layer 145 may include a semiconductor material having relatively low electrical conductivity.

[0075] Reference Figure 5H , the passivation layer 145 may be selectively removed in non-essential regions to expose the second electrode layer 134 .

[0076] Through this process, the mask pattern MP may be removed to expose the second electrode layer 134, and the passivation layer 145 may remain on the side surface of the light emitting structure 120. In addition, in this process, the metal nitride layer 112 may be removed and the ohmic contact layer 114 may be exposed. Although shown as a process of removing the metal nitride layer 112 in this process, the metal nitride layer 112 may be a conductive layer such as a TiN, TaN, and WN layer, and since the ohmic contact layer 114 in contact with the first conductive type semiconductor 122 may exist, the metal nitride layer 112 may remain to form the first electrode layer 110 together with the ohmic contact layer 114.

[0077] Reference Fig.5I , the semiconductor light emitting device having a nanorod structure can be separated from the nitride single crystal substrate 101 .

[0078] The light emitting structure 120 may be separated from the nitride single crystal substrate 101 by, for example, concentrating stress on the connection portion C1 of the light emitting structure 120 and the nitride single crystal substrate 101 so that the connection portion C1 is split. Such stress may be provided by relatively low heat or mechanical shock.

[0079] According to the present exemplary embodiment, the connection portion C1 is surrounded by the already separated pattern PA and thus can be easily separated therefrom. As described above, the separated surface (with Figure 1 The separated surface of the light emitting structure 120 (corresponding to the area A2 in FIG. 1 ) may be a cleavage surface or a surface where stress is concentrated due to a crack. Figure 1 The area A2 in the figure may have a value higher than (or relative to Fig.5I The vertical protrusion in the Figure 1The area A1 in FIG. 1 corresponds to the level of the area where the ohmic contact layer 114 is formed. The ohmic contact layer 114 can also be understood as being embedded in the first conductive type semiconductor 122 .

[0080] In the above-described exemplary embodiment, the light emitting structure has a nanorod structure in which a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer are sequentially stacked. In another exemplary embodiment, the light emitting structure may have a structure in which a first conductive type semiconductor is provided as a main nanorod, and an active layer and a second conductive type semiconductor layer are sequentially formed on a side surface of the nanorod as the first conductive type semiconductor, such as Figures 9 to 12 shown and described below.

[0081] Fig. 9 is a side cross-sectional view showing a semiconductor light emitting device according to example embodiments, Fig. 10A yes Fig. 9 1 is a plan view of a semiconductor light emitting device (showing the first surface).

[0082] Reference Fig. 9 , a semiconductor light emitting device 200 according to an example embodiment may include: a first conductive type semiconductor rod 222 having a first surface 222A and a second surface 222B opposite to each other and a side surface 222C connected between the first surface 222A and the second surface 222B; and a light emitting structure 220 including an active layer 225 and a second conductive type semiconductor layer 227 sequentially formed on a portion of the side surface 222C of the first conductive type semiconductor rod 222. The first conductive type semiconductor rod 222 includes a first portion 222_1 adjacent to the first surface 222A and a second portion 222_2 adjacent to the second surface 222B, and the active layer 225 and the second conductive type semiconductor layer 227 may be disposed on a side surface of the second portion 222_2 adjacent to the second surface 222B.

[0083] The semiconductor light emitting device 200 further includes an ohmic contact layer 214 as a first electrode layer disposed in a first area A1 of a first surface 222A of the first conductive type semiconductor rod 222 and a second electrode layer 234 connected to the second conductive type semiconductor layer 227 .

[0084] In the first surface 222A of the first conductive type semiconductor rod 222, the first region A1 (where the ohmic contact layer 214 is disposed) corresponds to a surface having a horizontal height lower than or vertically offset from a surface in the second region A2. The first surface 222A of the first conductive type semiconductor rod 222 may be a generally non-planar surface (having a protruding structure P in the second region A2). The first region A1 of the first surface 222A may have a flat surface. The second surface 222B of the first conductive type semiconductor rod 222 may be a generally flat surface.

[0085] As described above, the ohmic contact layer 214 in the present example embodiment may be embedded in the first conductive type semiconductor rods 222 in the first surface 222A.

[0086] like Fig. 9 As shown, the protruding structure P located in the second area A2 of the first surface 222A may be relative to Fig. 9 The first region A1 may be a crystal plane obtained when the nanorod type light emitting structure 220 is separated from the substrate, and the second region A2 of the first surface 222A may be a cleavage plane of the first conductive type semiconductor 222.

[0087] like Fig. 10A As shown, the first region A1 may surround the second region A2 in the first surface 222A of the first conductive type semiconductor rod 222. Therefore, since the second region A2 is surrounded by the already separated first region A1, the second region A2 may be easily separated even by heat or mechanical shock.

[0088] According to the present example embodiment, in the light emitting structure 220, the first conductive type semiconductor rods 222, the second conductive type semiconductor layer 227, and the active layer 225 may be the nitride semiconductors described in the above embodiments.

[0089] like Fig. 10A As shown, the first conductive type semiconductor rod 222 may have a cylindrical structure in which the first surface 222A has a substantially circular shape. The ohmic contact layer 214 as the first electrode layer may have a ring shape formed along the outer circumference of the first surface 222A. In another example embodiment, the structure of the first conductive type semiconductor rod 222 may have a columnar structure in which the first surface 222A has another polygonal shape (such as a quadrilateral shape), and may be configured according to Fig. 13C and Fig.15 The shape of the nanopore H is determined.

[0090] Similarly, the ring shape of the ohmic contact layer 214 may have another polygonal shape. In the present example embodiment, the size of the first surface 222A of the first conductive type semiconductor rod 222 may be equal to or slightly smaller than the outer region of the ohmic contact layer 214 .

[0091] The second portion 222_2 of the first conductive type semiconductor rod 222 may further include a regrown layer 222R and may have a width and shape different from those of the first portion 222_1 .

[0092] Fig. 10B and Fig. 10C Along Fig. 9 Cross-sectional views of the semiconductor light emitting device taken along lines II1-II1' and II2-II2' are shown.

[0093] Reference Fig. 10B , the first portion 222_1 of the first conductive type semiconductor rod 222 may have a cylindrical structure having a first width W1 and may have a circular cross section. Fig. 10C The second portion 222_2 of the first conductive type semiconductor rod 222 may further include a regrown layer 222R formed on the second portion side surface 222C2 thereof and may have a hexagonal columnar structure having a hexagonal cross section. The second width W2 of the second portion 222_2 of the first conductive type semiconductor rod 222 may be greater than the first width W1 by the regrown layer 222R.

[0094] The regrown layer 222R may be obtained by regrowing the first conductive type semiconductor on the second portion side surface 222C2 of the second portion 222_2 of the first conductive type semiconductor rod 222 through an MOCVD process. Surface damage of the second portion side surface 222C2 of the second portion 222_2 of the first conductive type semiconductor rod 222 may be eliminated by the regrown layer 222R, and a good quality active layer 225 may be deposited.

[0095] The current blocking layer 223 may be formed on the second surface 222B of the first conductive type semiconductor rod 222. The current blocking layer 223 in the present exemplary embodiment includes a second conductive type semiconductor film 223a and a first conductive type semiconductor film 223b sequentially formed on the second surface 222B of the first conductive type semiconductor rod 222. For example, the second conductive type semiconductor film 223a and the first conductive type semiconductor film 223b may be a p-type GaN film and an n-type GaN film, respectively. Therefore, even when a connection metal for bonding to the second electrode layer is formed on the current blocking layer 223 when mounted on an external device such as a display device, a reverse bias may be applied through the current blocking layer 223, so that an unnecessary current flowing through the second surface 222B of the first conductive type semiconductor rod 222 may be prevented. In the present exemplary embodiment, the current blocking layer 223 is formed on the second surface 222B of the first conductive type semiconductor rod 222 before the active layer 225 is formed. Therefore, the active layer 225 may also extend to the side surface of the current blocking layer 223. The current blocking layer 223 may be modified variously. For example, the current blocking layer 223 may also be formed of an insulator (see Fig.12 ).

[0096] The first electrode layer in this example embodiment may include an ohmic contact layer 214 connected to the first surface 222A of the first conductive type semiconductor rod 222. For example, the ohmic contact layer 214 may include at least one of silver (Ag), aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu), gold (Au), palladium (Pd), platinum (Pt), tin (Sn), tungsten (W), rhodium (Rh), iridium (Ir), ruthenium (Ru), magnesium (Mg), zinc (Zn), and alloy materials thereof. In example embodiments, the ohmic contact layer 214 may include W or WSi.

[0097] The second electrode layer 234 may be disposed on the second conductive type semiconductor layer 227. In the present exemplary embodiment, the second electrode layer 234 may be located only in the region corresponding to the second portion side surface 222C2 of the first conductive type semiconductor rod 222. For example, the second electrode layer 234 may include Ag, Ni, Al, Cr, Rh, Pd, Ir, Ru, Mg, Zn, Pt, or Au. In exemplary embodiments, the second electrode layer 234 may be a transparent electrode formed of a transparent conductive oxide or a transparent conductive nitride, or may include graphene. For example, the second electrode layer 234 may be selected from ITO, ZITO, ZIO, GIO, ZTO, FTO, AZO, GZO, In 4 Sn 3 O 12 and Zn (1-x) Mg x At least one of O(0≤x≤1).

[0098] The semiconductor light emitting device 200 according to the present exemplary embodiment may include an ohmic contact layer 214 as a first electrode layer and a second electrode layer 234 while having a nanorod structure. Similar to the previous exemplary embodiment, the ohmic contact layer 214 may be provided before growing the light emitting structure 220, and thus may have a form embedded in the first surface 222A of the first conductive type semiconductor rod 222. The ohmic contact layer 214 may be formed in a first region A1 of the first surface 222A, and the second region A2 may be a cut surface such as a cleavage plane obtained when the semiconductor light emitting device 200 is separated from the substrate. Although slightly different depending on the crystal plane split when separated from the substrate, the second region A2 may have a relative Fig. 9 The second area A2 may have a structure that protrudes higher or beyond the surface in the first area A1 in a vertical direction. In addition, the second area A2 may have a structure surrounded by the first area A1 so that the second area A2 may be easily separated.

[0099] Fig.11 and Fig.12 is a side cross-sectional view illustrating a semiconductor light emitting device according to various example embodiments.

[0100] Reference Fig.11 The semiconductor light emitting device 200′ according to the example embodiment may be similar to Figures 9 to 10C The semiconductor light emitting device 200 is shown. Unless otherwise described, the components of this example embodiment may refer to those of Figures 9 to 10C The description of the same or similar components of the semiconductor light emitting device 200 shown in the figure should be understood.

[0101] The second electrode layer and the active layer are not disposed on the second surface of the first conductive type semiconductor rod. Therefore, the current blocking structure may not be disposed on the second surface of the first conductive type semiconductor rod. Similar to the previous embodiment, the semiconductor light emitting device according to the present exemplary embodiment has a structure that emits light using only the side surface of the second portion of the first conductive type semiconductor rod.

[0102] The first electrode layer 210 may be embedded in the first surface 222A of the first conductive type semiconductor rod 222. The first electrode layer 210 in the present exemplary embodiment may have a multi-layer structure. The first electrode layer 210 may include an ohmic contact layer 214 connected to the first conductive type semiconductor rod 222 and a metal nitride layer 212 disposed on the ohmic contact layer 214.

[0103] For example, the ohmic contact layer 214 may include at least one of Ag, Al, Ni, Cr, Cu, Au, Pd, Pt, Sn, W, Rh, Ir, Ru, Mg, Zn, and alloy materials thereof. In example embodiments, the ohmic contact layer 214 may include W or WSi. For example, the metal nitride layer 212 may include TiN, TaN, or WN as a conductive layer.

[0104] Reference Fig.12 , except that the protruding structure P' has a different shape, the current blocking layer 223' includes an insulator, and the second electrode layer 234' extends on the upper surface of the first conductive type semiconductor rod 222, the semiconductor light emitting device 200" according to the example embodiment may be similar to Figures 9 to 10C The semiconductor light emitting device 200 is shown. Unless otherwise described, the components of this example embodiment may refer to those of Figures 9 to 10C The description of the same or similar components of the semiconductor light emitting device 200 shown in the figure should be understood.

[0105] The semiconductor light emitting device 200″ according to the present exemplary embodiment has a protruding structure P′ at the first surface 222A of the first conductive type semiconductor rod 222. The first region A1 (where the ohmic contact layer 214 as the first electrode layer is disposed) may have a surface that is lower in level than the surface in the second region A2 or vertically offset relative to the surface in the second region A2.

[0106] like Fig.12 As shown, the protruding structure P' may be formed at least partially below the ohmic contact layer 214. The protruding structure P' may have a surface obtained by concentrating stress on a portion surrounded by the ohmic contact layer 214 to separate the light emitting structure 220 from the substrate, and thus may be split into various shapes due to the presence of existing cracks (e.g., crystal defects), etc. For example, as in the present exemplary embodiment, the second area A2 of the first surface 222A may have an inclined surface.

[0107] The current blocking layer 223 ′ in the present example embodiment may be formed of an insulator. Fig. 9 The semiconductor light emitting device 200 shown can be implemented using a PN junction structure using a reverse bias. In this example embodiment, an electrical insulating material can be formed as in this example embodiment to provide a reference Fig. 9 The same current blocking effect as the exemplary embodiment. When the growth inhibition layer such as SiN layer (see Fig.13E When the growth inhibition layer 257 in the embodiment of the present invention is retained without being removed, a current blocking layer formed of an insulator can be provided.

[0108] The second electrode layer 234' in the present example embodiment may extend on the upper surface of the first conductive type semiconductor rod 222. Even in the case where the second electrode layer 234' is positioned on the upper surface of the first conductive type semiconductor rod 222, current may not be conducted to the upper surface of the first conductive type semiconductor rod 222 through the current blocking layer 223'.

[0109] FIG. 13A to FIG. 13E is a cross-sectional view showing main processes of a method of manufacturing a semiconductor light emitting device (in detail, a method of forming first conductive type semiconductor nanorods) according to an example embodiment, FIG. 14A to FIG. 14F are cross-sectional views illustrating main processes of a method of manufacturing a semiconductor light emitting device according to example embodiments.

[0110] First, refer to Fig.13A , a pattern PA including a metal layer 212 ′ and an ohmic contact layer 214 may be formed on the nitride single crystal substrate 201 .

[0111] This result can be obtained by Figure 5A and Figure 5B In detail, the metal layer 212' and the ohmic contact layer 214 may be sequentially deposited on the nitride single crystal substrate 201 using CVD or sputtering, and a pattern for the first electrode layer may be formed. Each pattern PA may have a ring shape surrounded by one area.

[0112] The metal layer 212' used in this process may include a metal capable of forming a metal nitride by reacting with a nitrogen component of the nitride single crystal substrate 201 under single crystal growth conditions for a light emitting structure. For example, the metal layer 212' may include Ta, Ti, or W.

[0113] Reference Fig. 13B , an amorphous insulating layer ML1 may be formed on the nitride single crystal substrate 201 to cover the pattern PA.

[0114] The amorphous insulating layer ML1 may be used as a molding structure for forming a first conductive type semiconductor rod. The amorphous insulating layer ML1 may include a first insulating film 251, a second insulating film 252, and a third insulating film 253 having different etching rates. In example embodiments, the first insulating film 251 and the third insulating film 253 may be formed of the same material. For example, the first insulating film 251 and the third insulating film 253 may include SiO 2 , and the second insulating film 252 may include SiN.

[0115] Reference Fig. 13C , a nanohole H may be formed in the amorphous insulating layer ML1. Fig.15 It is shown Fig. 13C A plan view of the process result (after nanopore formation) is shown.

[0116] In this process, the first insulating film 251, the second insulating film 252, and the third insulating film 253 may all be etched to form a nanohole H corresponding to the first conductive type semiconductor rod. Such etching may be achieved, for example, by dry etching using plasma. The nanohole H may be formed as shown in FIG. Fig.15 The previously formed ring pattern PA of the metal layer 212' and the ohmic contact layer 214 may be exposed through the nanohole H. In this example embodiment, the nanohole H may be formed to correspond to the outer edge of the pattern PA having a ring bottom or slightly smaller than the outer line of the pattern PA.

[0117] Reference Fig.13D , a first conductive type semiconductor rod 222 may be formed in the nanohole H.

[0118] The first conductive type semiconductor rod 222 may be formed in the nanohole H using, for example, a metal organic chemical vapor deposition (MOCVD) process. For example, the first conductive type semiconductor rod 222 may be formed of n-type GaN. This growth process may be performed at a relatively high temperature. Therefore, during the growth process, nitrogen in a region of the nitride single crystal substrate 201 adjacent to the metal layer 212' may migrate toward the metal layer 212' to react with the metal layer 212', thereby forming a metal nitride layer 212. For example, the metal nitride layer 212 may include TiN, TaN, or WN.

[0119] As a result of this reaction, vacancies due to nitrogen migration may be generated in the adjacent region of the nitride single crystal substrate 201 adjacent to the metal layer 212', and the metal component MG (e.g., gallium) left in the high temperature process melts to form a void region V0. The void region V0 may be formed according to the pattern region in contact with the metal layer (or metal nitride layer 212), and may facilitate subsequent processes (see Fig.14F ) in the separation of the light emitting structure 220.

[0120] In the present exemplary embodiment, the second conductive type semiconductor film 223a and the first conductive type semiconductor film 223b may be sequentially formed on the first conductive type semiconductor rod 222 as the current blocking layer 223. For example, the second conductive type semiconductor film 223a and the first conductive type semiconductor film 223b may be a p-type GaN film and an n-type GaN film, respectively. The p-type GaN film may be formed at a thickness of 1×10 17 / cm 3 Up to 1×10 18 / cm 3 The concentration of p-type impurities is doped.

[0121] Reference Fig.13E, the amorphous insulating layer ML1 may be partially removed to expose second portions of side surfaces 222C2 of the first conductive type semiconductor rods 222 .

[0122] In this process, the third insulating film 253 may be removed to expose the second partial side surface 222C2 of the first conductive type semiconductor rod 222, while the first partial side surface 222C1 of the first conductive type semiconductor rod 222 may still be covered by the partially removed amorphous insulating layer ML2.

[0123] Before partially removing the amorphous insulating layer ML1, a growth suppression layer 257 may be formed on the upper surface of the first conductive type semiconductor rods 222, respectively. The growth suppression layer 257 may be used as an element for suppressing further growth on the upper surface of the first conductive type semiconductor rods 222 in a subsequent semiconductor growth process. The growth suppression layer 257 may be formed of a material that is the same as or similar to that of the second insulating film 252, which is an amorphous insulating material. For example, the growth suppression layer 257 may include SiN. Therefore, even in the case where a process of partially removing the amorphous insulating layer ML1 is performed under the etching conditions of the third insulating film 253, the growth suppression layer 257 may remain together with the second insulating film 252 used as an etching stop layer.

[0124] Next, refer to Fig.14A , a regrown layer 222R may be formed on the second portion side surface 222C2 of the first conductive type semiconductor rod 222 . Fig.16 It is shown Fig.14A A plan view of the process result (after regrowth) is shown.

[0125] The regrown layer 222R may be formed under conditions similar to the MOCVD process for the first conductive type semiconductor rods 222. Surface damage of the second portion side surface 222C2 of the first conductive type semiconductor rods 222 may be eliminated by the regrown layer 222R. Therefore, the active layer 225 and the second conductive type semiconductor layer 227 on the regrown layer 222R may be grown as relatively high quality single crystal layers.

[0126] The regrown layer 222R may have a stable crystal plane. Therefore, the upper region of the first conductive type semiconductor rod 222 on which the regrown layer 222R is formed may be as shown in FIG. Fig.16 The upper region of the first conductive type semiconductor rod 222 may have a hexagonal columnar structure. The width of the upper region of the first conductive type semiconductor rod 222 may be greater than that of the lower region by the additional regrown layer 222R. As described above, through this process, the lower region of the first conductive type semiconductor rod 222 may have a cylindrical structure, and the upper region of the first conductive type semiconductor rod 222 may have a hexagonal columnar structure.

[0127] Reference Fig. 14B, an active layer 225 and a second conductive type semiconductor layer 227 may be sequentially formed on the second portion of the side surface 222C2 of the first conductive type semiconductor rod 222. Fig. 14C As shown, a second electrode layer 234 ′ may be formed on the exposed portions of the first conductive type semiconductor rods 222 .

[0128] In this example embodiment, Fig.14D As shown, the portion of the second electrode layer 234' disposed on the upper surface of the first conductive type semiconductor rod 222 may be removed using an etch-back or anisotropic etching process in such a manner that the second electrode layer 234 may remain only on the second conductive type semiconductor layer 227. In addition, the portion of the second electrode layer 234' disposed between the first conductive type semiconductor rods 222 may also be removed in this etching process to expose the second insulating film 252 of the amorphous insulating layer ML2, and thus, the growth inhibition layer 257 may be removed from the upper surface of the first conductive type semiconductor rod 222 together with the second insulating film 252.

[0129] Then, if Fig.14E As shown, the first insulating film 251 may be removed to expose the first portion of the side surface 222C1 of the first conductive type semiconductor rod 222. In this process, the metal nitride layer 212 may be removed and the ohmic contact layer 214 may be exposed. In another example embodiment, the metal nitride layer 212 may be a conductive layer (such as a TiN, TaN, or WN layer) and may be provided as the first electrode layer 210 together with the ohmic contact layer 214.

[0130] Reference Fig.14F , the semiconductor light emitting device 200 having a nanorod structure can be separated from the nitride single crystal substrate 201 .

[0131] The light emitting structure 220 can be separated from the nitride single crystal substrate 201 by, for example, concentrating stress on the connection portion between the light emitting structure 220 and the nitride single crystal substrate 201 so that the connection portion is split. Such stress can be provided by relatively slight heat or mechanical shock. As described above, since the connection portion is surrounded by the separated pattern PA, the connection portion can be easily separated.

[0132] The semiconductor light emitting devices 100, 100', 200, 200', and 200" having the nanorod structure as described above may be advantageously used as light sources for respective pixels constituting a display device. Fig.17 is a side sectional view illustrating a display apparatus employing a semiconductor light emitting device according to example embodiments.

[0133] Reference Fig.17, the display device 500 according to the example embodiment may include semiconductor light emitting devices 100R, 100G, and 100B having a nanorod structure, which may be disposed in each pixel region. The semiconductor light emitting devices 100R, 100G, and 100B having a nanorod structure may be configured to emit red light, green light, and blue light, respectively. Each pixel may be defined by a pixel defining layer 350.

[0134] The semiconductor light emitting devices 100R, 100G, and 100B having a nanorod structure may respectively have a length disposed between the first electrode portion 310 and the second electrode portion 320. The semiconductor light emitting devices 100R, 100G, and 100B having a nanorod structure may be self-aligned between the first electrode portion 310 and the second electrode portion 320, for example, using an electrical bias, and may be fixed by an insulating support 330.

[0135] Between the substrate 410 and the semiconductor light emitting devices 100R, 100G, and 100B, a driving circuit device 380 such as a transistor (Tr) and a capacitor (C) and an insulating film 360 covering the driving circuit device 380 may be further formed. A buffer layer 420 may be formed on the substrate 410 .

[0136] In example embodiments, a reflective film 370 may be further disposed under each of the semiconductor light emitting devices 100R, 100G, and 100B. The reflective film 370 may be formed separately from the circuit device 380, or may be formed integrally with at least one circuit device 380. For example, the reflective film 370 may also be configured by expanding the area of ​​at least one electrode constituting one or more transistors (Tr) and / or capacitors (C).

[0137] Fig.18 It is shown Fig.17 A perspective view of one pixel 500u of the display device is shown. For convenience of description, the driving circuit device 380 and the insulating film 360 disposed between the substrate 410 and the semiconductor light emitting devices 100R, 100G, and 100B are omitted.

[0138] Reference Fig.18 , the semiconductor light emitting device 100 having a nanorod structure may be disposed between the first electrode portion 310 and the second electrode portion 320. The ohmic contact layer 114 (first electrode layer) and the second electrode layer 134 of the semiconductor light emitting device 100 having a nanorod structure may be connected to the first electrode portion and the second electrode portion respectively through the first connection electrode 315 and the second connection electrode 325. The first connection electrode 315 and the second connection electrode 325 may be formed of a transparent conductive material such as ITO, IZO, ITZO, etc.

[0139] By summarizing and reviewing, a general display device may include a display panel, such as a display panel including a liquid crystal display (LCD) and a backlight. The display device can be implemented without a separate backlight by using an LED device for a single pixel. Such a display device can be compact and can achieve high brightness with excellent light efficiency.

[0140] As explained above, according to the example embodiments, the first conductive type semiconductor may have an ohmic contact layer, and the driving voltage of the semiconductor light emitting device having the nanorod structure may be reduced. When the semiconductor light emitting device is applied to each pixel of a display device, the color uniformity may be prevented from being reduced due to the uneven driving voltage.

[0141] As set forth above, the embodiment may provide a nanorod shaped semiconductor light emitting device having improved contact resistance. The embodiment may also provide a display device having a nanorod shaped semiconductor light emitting device having improved electrical characteristics.

[0142] Example embodiments are disclosed herein, and although specific terms are employed, they are used and interpreted only in a general and descriptive sense, and not for limitation. In some cases, as will be apparent to one of ordinary skill in the art, from the filing of this application, unless otherwise specifically indicated, the features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with the features, characteristics, and / or elements described in conjunction with other embodiments. 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, comprising: A light emitting structure having a rod shape, the light emitting structure having a first surface and a second surface opposite to each other and a side surface connected between the first surface and the second surface, and the light emitting structure includes an active layer, a second conductive type semiconductor, and a first conductive type semiconductor providing the first surface; a first electrode layer, which is located on a first area of ​​a first surface of the light emitting structure and connected to the first conductive type semiconductor, wherein a level of the first area is vertically offset relative to a level of a second area adjacent to the first area, the second area being an area of ​​the first surface other than the first area; as well as a second electrode layer connected to the second conductive type semiconductor, The first conductive type semiconductor in the second region protrudes downward in a direction away from the second surface beyond the first conductive type semiconductor in the first region, and the first electrode layer contacts the first conductive type semiconductor in the first region below the first conductive type semiconductor in the first region.

2. The semiconductor light emitting device according to claim 1, wherein: The first surface of the light emitting structure is a non-planar surface from which the second region protrudes, and the second surface of the light emitting structure is a planar surface.

3. The semiconductor light emitting device according to claim 1, wherein: The second region of the first surface protrudes beyond the first electrode layer.

4. The semiconductor light emitting device according to claim 1, wherein: The second region of the first surface is a cleavage plane of the first conductive type semiconductor.

5. The semiconductor light emitting device according to claim 1, wherein: The first region surrounds the second region.

6. The semiconductor light emitting device according to claim 1, wherein: The first electrode layer includes an ohmic contact layer connected to the first conductive type semiconductor.

7. The semiconductor light emitting device according to claim 6, wherein: The first electrode layer further includes a metal nitride layer disposed on the ohmic contact layer.

8. The semiconductor light emitting device according to claim 1, wherein: The second electrode layer includes a transparent electrode material.

9. The semiconductor light emitting device according to claim 1, wherein: The first conductivity type semiconductor, the second conductivity type semiconductor and the active layer are nitride semiconductors.

10. The semiconductor light emitting device according to claim 1, wherein: The first conductive type semiconductor and the second conductive type semiconductor provide the first surface and the second surface, respectively, and the active layer is disposed between the first conductive type semiconductor and the second conductive type semiconductor.

11. The semiconductor light emitting device according to claim 1, wherein: The first conductive type semiconductor has a rod shape, and The active layer and the second conductive type semiconductor are sequentially stacked on a portion of a side surface of the first conductive type semiconductor adjacent to the second surface.

12. A semiconductor light emitting device, comprising: A light emitting structure having a rod shape, the light emitting structure having a first surface and a second surface opposite to each other and a side surface connected between the first surface and the second surface, and the light emitting structure including a first conductive type semiconductor layer and a second conductive type semiconductor layer providing the first surface and the second surface, respectively, and an active layer provided between the first conductive type semiconductor layer and the second conductive type semiconductor layer; A first electrode layer connected to the first conductive type semiconductor layer and disposed on a first area of ​​the first surface of the light emitting structure, wherein a level of the first area is vertically offset relative to a level of a second area adjacent to the first area; as well as a second electrode layer located on a second surface of the light emitting structure and connected to the second conductive type semiconductor layer, Wherein, the light emitting structure has a hexagonal columnar structure, The first electrode layer has a circular ring shape, and its width is greater than the width of the first surface of the light emitting structure.

13. The semiconductor light emitting device according to claim 12, wherein: The first surface of the light emitting structure is a non-planar surface from which the second region protrudes, and the second surface of the light emitting structure is a planar surface.

14. The semiconductor light emitting device according to claim 12, wherein: The first electrode layer has a ring shape, and the second electrode layer is disposed substantially on the entire second surface of the light emitting structure. 15 . The semiconductor light emitting device according to claim 12 , further comprising a passivation layer surrounding a side surface of the light emitting structure.

16. A semiconductor light emitting device, comprising: A first conductive type semiconductor rod having a first surface and a second surface opposite to each other and a side surface connected between the first surface and the second surface, the first conductive type semiconductor rod including a first portion adjacent to the first surface and a second portion adjacent to the second surface; an active layer and a second conductivity type semiconductor layer sequentially disposed on a side surface of the second portion of the first conductivity type semiconductor rod; a first electrode layer connected to the first conductive type semiconductor rod and disposed in a first region of a first surface of the first conductive type semiconductor rod, wherein the first region is vertically offset from a second region adjacent thereto, the second region being a region of the first surface other than the first region; as well as a second electrode layer, which is disposed on the second conductive type semiconductor layer; The first conductive type semiconductor rods in the second region protrude downwardly beyond the first conductive type semiconductor rods in the first region in a direction away from the second surface, and the first electrode layer contacts the first conductive type semiconductor rods in the first region below the first conductive type semiconductor rods in the first region. 17 . The semiconductor light emitting device according to claim 16 , further comprising a second conductive type semiconductor film and a first conductive type semiconductor film sequentially disposed on the second surface of the first conductive type semiconductor rod.

18. The semiconductor light emitting device according to claim 16, further comprising a current blocking layer located on the second surface of the first conductive type semiconductor rod, wherein: The second electrode layer extends on the current blocking layer.

19. The semiconductor light emitting device according to claim 16, wherein: The first electrode layer has a ring shape.

20. The semiconductor light emitting device according to claim 16, wherein: The width of the first portion of the first conductive type semiconductor rod is greater than the width of the second portion.

21. The semiconductor light emitting device according to claim 20, wherein: The first portion of the first conductive type semiconductor rod has a cylindrical structure, and the second portion of the first conductive type semiconductor rod has a hexagonal columnar structure.

22. The semiconductor light emitting device according to claim 16, wherein: The first electrode layer has a ring shape, and The first electrode layer is disposed along an outer periphery of a first surface of the first conductive type semiconductor rod.

23. A display device comprising: Multiple pixels, a first electrode portion and a second electrode portion provided in a pixel among the plurality of pixels, the first electrode portion being spaced apart from the second electrode portion, and The semiconductor light emitting device according to claim 1 is disposed between the first electrode portion and the second electrode portion such that the first electrode layer of the semiconductor light emitting device is connected to the first electrode portion and the second electrode layer of the semiconductor light emitting device is connected to the second electrode portion.

Images