KR102571788B1 - Semiconductive device, light emitting device and lighting apparatus having the same - Google Patents

Abstract

A semiconductor device according to an embodiment includes a first conductivity-type semiconductor layer having a central region and a first region around the central region that is lower than a height of a top surface of the central region, an active layer disposed on the first conductivity-type semiconductor layer, and the a light emitting structure including a second conductive type semiconductor layer disposed on the active layer; a first electrode disposed in a first region of the first conductive semiconductor layer and electrically connected to the first conductive semiconductor layer; a first electrode layer disposed on the light emitting structure and the first electrode and electrically connected to the first electrode; a second electrode layer disposed between the first electrode layer and the second conductive semiconductor layer and electrically connected to the second conductive semiconductor layer; and a first insulating layer disposed between the first electrode layer and the second electrode layer, wherein the first region of the first conductive type semiconductor layer has a first axis direction and a second axis direction orthogonal to each other around the central region. direction, the first electrode is disposed in the same axial direction as the first and second axial directions in which the first region is disposed, and has the same length as each other.

Description

Semiconductor device, light emitting device and lighting device having the same

The embodiment relates to a semiconductor device.

The embodiment relates to a light emitting device having a semiconductor.

The embodiment relates to a lighting device having a semiconductor element or a light emitting element.

Semiconductor devices including compounds such as GaN and AlGaN have band gap energy that is wide and easily adjustable, and can be used as various devices such as light emitting devices, light receiving devices, and various diodes.

In particular, light emitting devices such as light emitting diodes or laser diodes using group III-V or group II-VI compound semiconductor materials of semiconductors are developed in thin film growth technology and device materials to produce red, green, Various colors such as blue and ultraviolet can be realized, and white light with high efficiency can be realized by using fluorescent materials or combining colors. , safety, and environmental friendliness.

An embodiment provides a semiconductor device or light emitting device in which a first electrode is disposed around an outer circumference of a first conductive type semiconductor layer.

The embodiment provides a semiconductor element or light emitting element in which a first electrode is continuously or discontinuously disposed around an outer circumference of a first conductive type semiconductor layer with a predetermined length.

Embodiments provide a semiconductor device or light emitting device having a semiconductor substrate and having an excellent current spreading effect.

The embodiment provides a semiconductor device or light emitting device with improved reflection area of the first electrode layer.

The embodiment provides a semiconductor device or light emitting device with improved heat dissipation efficiency.

An embodiment provides a flip chip type semiconductor device or light emitting device.

The embodiment may improve electrical reliability of a light unit or lighting device having the above-described semiconductor or light emitting device.

A semiconductor device according to an embodiment includes a first conductivity-type semiconductor layer having a central region and a first region around the central region that is lower than a height of a top surface of the central region, an active layer disposed on the first conductivity-type semiconductor layer, and the a light emitting structure including a second conductive type semiconductor layer disposed on the active layer; a first electrode disposed in a first region of the first conductive semiconductor layer and electrically connected to the first conductive semiconductor layer; a first electrode layer disposed on the light emitting structure and the first electrode and electrically connected to the first electrode; a second electrode layer disposed between the first electrode layer and the second conductive semiconductor layer and electrically connected to the second conductive semiconductor layer; and a first insulating layer disposed between the first electrode layer and the second electrode layer, wherein the first region of the first conductive type semiconductor layer has a first axis direction and a second axis direction orthogonal to each other around the central region. direction, the first electrode may be disposed in the same axial direction as the first and second axial directions in which the first region is disposed, and may have the same length.

A lighting device according to an embodiment includes a circuit board; a plurality of semiconductor elements arranged on the circuit board; and an electrode pattern electrically connecting the plurality of semiconductor elements to the circuit board, wherein the semiconductor element comprises: a substrate having a pattern; A light emitting structure disposed on the substrate, the light emitting structure, a first conductive semiconductor layer having a central region and a first region around the central region that is lower than the height of the upper surface of the central region, and on the first conductive semiconductor layer an active layer disposed thereon, and a second conductivity type semiconductor layer disposed on the active layer; a first electrode disposed in a first region of the first conductive semiconductor layer and electrically connected to the first conductive semiconductor layer; a first electrode layer disposed on the light emitting structure and the first electrode and electrically connected to the first electrode; a second electrode layer disposed between the first electrode layer and the second conductive semiconductor layer and electrically connected to the second conductive semiconductor layer; a first insulating layer disposed between the first electrode layer and the second electrode layer; and at least one pad on the first electrode layer, wherein a first region of the first conductive semiconductor layer is disposed around the central region in a first axis direction and a second axis direction orthogonal to each other, The electrodes are disposed to have the same length along the same axial direction as the first and second axial directions in which the first region is disposed, and the length of the first electrode in the first axial direction and the second axial direction is the same as that of the substrate. 1/2 or more of the length of , and the first electrode layer may have a lower surface area larger than that of the first conductive semiconductor layer.

According to an embodiment, the first electrodes disposed in the first axis direction and the second axis direction may be connected to each other. The first electrode may be continuously connected along different axial directions around a central region of the first conductive type semiconductor layer.

According to an embodiment, the first insulating layer is formed between the first electrode and the first conductive semiconductor layer at a corner of the first region of the first conductive semiconductor layer where the first axial direction and the second axial direction are orthogonal to each other. is placed on The first electrode may be spaced from a vertex of a corner region of the first conductive type semiconductor layer at equal intervals in different axial directions. The first insulating layer may be connected to the second insulating layer on the first region, and the first insulating layer and the second insulating layer may be spaced apart from an outermost edge of the first conductive type semiconductor layer.

According to the embodiment, the length of the first electrode disposed in the first axis direction or the second axis direction may be 1/2 or more of the length of the first region in the first axis direction or the second axis direction. The first electrode may have a rotationally symmetrical shape with respect to the central axis of the light emitting structure.

According to an embodiment, the first electrode layer may include a contact portion disposed on the first region and contacting the first conductive type semiconductor layer. The contact portion of the first electrode layer may be disposed inside and outside the first electrode. According to an embodiment, the first electrode layer may have branch electrodes extending to a region between the first pad and the second pad.

According to the embodiment, the side of the light emitting structure is inclined, and the outer portion of the first insulating layer may be disposed between the first electrode and the side of the light emitting structure. An area of the lower surface of the first electrode layer may be larger than that of the lower surface of the first conductive semiconductor layer.

According to the embodiment, the first pad includes a plurality of first concave portions on an upper surface, and the second pad includes a plurality of second concave portions on an upper surface, and the depth of the second concave portions is the depth of the first concave portions. Can be placed more deeply.

According to the embodiment, the first pad may have a plurality of first protrusions protruding in the direction of the first electrode layer, and the second pad may have a plurality of second protrusions protruding in the direction of the second electrode layer.

According to an embodiment, a substrate disposed under the first conductive semiconductor layer may be included, and the substrate may be formed of a semiconductor of the same material as the first conductive semiconductor layer. A conductive layer may be included between the second electrode layer and the second conductive semiconductor layer, the first electrode layer and the second electrode layer may reflect light, and the conductive layer may have a material different from that of the first electrode. .

According to the embodiment, light efficiency of a semiconductor device or a light emitting device may be improved.

According to the embodiment, light reflection efficiency in a semiconductor device or a light emitting device may be improved.

According to the embodiment, heat dissipation efficiency of a semiconductor device or a light emitting device may be improved.

According to the embodiment, the reliability of a high-output semiconductor device or light emitting device can be improved.

According to the embodiment, the reliability of a light unit or lighting device having a high-output semiconductor element or light emitting element may be improved.

1 is a plan view illustrating a semiconductor device according to a first embodiment.
FIG. 2 is an AA-side cross-sectional view of the semiconductor device of FIG. 1 .
FIG. 3 is a partially enlarged view of the semiconductor device of FIG. 2 .
FIG. 4 is a BB-side cross-sectional view of the semiconductor device of FIG. 1 .
5 is a partially enlarged view of the semiconductor device of FIG. 4 .
6 is a CC-side cross-sectional view of the semiconductor device of FIG. 1 .
FIG. 7 is a view for explaining a contact area of a first electrode disposed in a first region of a first conductivity type semiconductor layer in the semiconductor device of FIG. 1 .
FIG. 8 is a view showing a region occupied by a first electrode layer in the semiconductor device of FIG. 1 .
FIG. 9 is an enlarged view showing the second pad and the first electrode layer in FIG. 4 .
FIG. 10 is a view showing a concave-convex pattern of the substrate in FIG. 4 .
11 is a view for explaining an inclination angle of a side surface of a light emitting structure of a semiconductor device according to an embodiment.
FIG. 12 is a comparative example of FIG. 11 , and is a view for explaining a problem caused by an inclination of a light emitting structure of a semiconductor device.
13 is another example of the first electrode layer in the first region of the first conductivity type semiconductor layer according to the embodiment.
FIG. 14 is a view showing a modified example of the first electrode in the semiconductor device of FIG. 1 .
FIG. 15 is a view showing a modified example of the first electrode in the semiconductor device of FIG. 1 .
16 and 17 are views illustrating modified examples of a first protrusion of a first pad and a second protrusion of a second pad in the semiconductor device of FIG. 1 .
FIG. 18 is a view showing an example of a first electrode layer having branch electrodes in the semiconductor device of FIG. 1 .
FIG. 19 is a view showing a lighting device in which a phosphor layer is disposed on the semiconductor device of FIG. 4 as a second embodiment.
FIG. 20 is a view showing a lighting device in which a phosphor layer and a reflective member are disposed around the semiconductor device of FIG. 4 as a third embodiment.
FIG. 21 is a diagram illustrating a lighting device according to a fourth embodiment in which the semiconductor elements of FIG. 4 are arranged on a circuit board.
22 is a graph comparing light output and light extraction efficiency of a semiconductor device having a semiconductor substrate according to an embodiment and a device having a sapphire substrate of a comparative example.
23 is a graph comparing current droop of a semiconductor device having a semiconductor substrate according to an embodiment and a device having a sapphire substrate of a comparative example.
24 is a graph comparing thermal droop of a semiconductor device having a semiconductor substrate according to an embodiment and a device having a sapphire substrate of a comparative example.
25 is a view comparing reflectance according to the material of the second electrode according to the embodiment.

The present embodiments may be modified in other forms or combined with each other, and the scope of the present invention is not limited to each of the embodiments described below. Even if a matter described in a specific embodiment is not described in another embodiment, it may be understood as a description related to another embodiment, unless there is a description contrary to or contradictory to the matter in another embodiment. For example, if the characteristics of component A are described in a specific embodiment and the characteristics of component B are described in another embodiment, the opposite or contradictory description even if the embodiment in which components A and B are combined is not explicitly described. Unless there is, it should be understood as belonging to the scope of the present invention.

Hereinafter, embodiments of the present invention that can specifically realize the above object will be described with reference to the accompanying drawings. In the description of the embodiment according to the present invention, in the case of being described as being formed on "on or under" of each element, on or under (on or under) or under) includes both elements formed by directly contacting each other or by indirectly placing one or more other elements between the two elements. In addition, when expressed as "on or under", it may include the meaning of not only the upward direction but also the downward direction based on one element.

The semiconductor device may include various electronic devices such as a light emitting device and a light receiving device, and the light emitting device and the light receiving device may include a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer. A semiconductor device according to this embodiment may be a light emitting device. The light emitting device emits light by recombination of electrons and holes, and the wavelength of the light may be determined by a material-specific energy band gap. Accordingly, the wavelength of emitted light may vary depending on the composition of the material.

<Example>

1 is a plan view showing a semiconductor device according to a first embodiment, FIG. 2 is a cross-sectional view of the semiconductor device of FIG. 1 from the A-A side, FIG. 3 is a partially enlarged view of the semiconductor device of FIG. 2, and FIG. A B-B side sectional view of the semiconductor device, FIG. 5 is a partially enlarged view of the semiconductor device of FIG. 4, and FIG. 6 is a C-C side sectional view of the semiconductor device of FIG.

1 to 6 , the semiconductor device 100 includes a substrate 11, a first conductivity type semiconductor layer 21, an active layer 22, and a second conductivity type semiconductor layer 23 on the substrate 11. ) Having a light emitting structure 20, a first electrode layer 65 on the light emitting structure 20, a second electrode layer 63 between the first electrode layer 65 and the light emitting structure 20, the first A first region 21A lower than the height of the central region around the central region of the conductive semiconductor layer 21, and a first electrode 67 on the first region 21A.

The semiconductor device 100 according to the embodiment may be implemented as at least one of a light emitting device, a light receiving device, and a light sensing device. When the semiconductor device 100 is a light emitting device, it may emit at least one of ultraviolet, visible, and infrared wavelengths. When the semiconductor device 100 is a light receiving device or a light sensing device, it may be a device that receives or senses light of a specific wavelength. In an embodiment, the semiconductor device 100 may be implemented as a device having a transparent substrate, for example, a substrate 11 made of a conductive or insulating material.

<substrate>

The substrate 11 may be formed of a compound semiconductor, for example, a group III-V compound semiconductor. The substrate 11 may be formed of the same material as at least one layer of semiconductor constituting the light emitting structure 20 . The substrate 11 may be formed of a material having the same refractive index as the first conductive semiconductor layer 21, thereby preventing defects and reducing light loss. The substrate 11 according to the embodiment may be an insulating or unintentional doped semiconductor substrate. When a dopant is doped into the substrate 11, light extraction efficiency due to impurities such as the dopant may decrease, and thus the substrate 11 may be a semiconductor layer in which dopant is not intentionally injected. For convenience of description, the substrate 11 will be described as a semiconductor substrate.

The substrate 11 may be formed of a GaN-based semiconductor, for example, a GaN semiconductor. The substrate 11 may be a bulk GaN single crystal substrate. In the semiconductor device 100 having such a substrate 11, dislocation density can be suppressed compared to the case of using a sapphire substrate, and crystallinity in the semiconductor layer can be improved. The semiconductor device 100 using a GaN-based semiconductor as the substrate 11 can suppress current concentration and reduce heat generation by improving current diffusion, and has a larger pattern for light extraction on the substrate 11. can form As another example, the substrate 11 is GaN or GaAs, ZnO, GaP, InP, and Ga ₂ O ₃ It may include any one of, but is not limited thereto.

The substrate 11 may include a plurality of protrusions (not shown) on an upper portion. The plurality of protrusions may have a polygonal pyramid shape, but is not limited thereto. The thickness T1 of the substrate 11 may be formed in a range of 30 μm or more, for example, 30 μm to 150 μm. In this case, when separating into individual devices, it is difficult to separate the substrate 11 or the thickness of the substrate 11 is thick, so light extraction efficiency may be reduced.

The substrate 11 may include a pattern 11A at a lower portion. The pattern 11A may have a cone shape, for example, a polygonal pyramid shape. The polygonal pyramidal shape may include a hexagonal pyramidal shape. 10, the height H1 of the pattern 11A may have a height of 1% to 4% of the thickness T1 of the substrate 11. For example, the substrate 11 may be a GaN-based semiconductor. In this case, the pattern 11A may be formed to a height H1 of 10 μm. The patterns 11A may have different sizes or different heights H1. The pattern 11A may include a texture structure. The extraction efficiency of the light emitted by the pattern 11A can be improved.

The substrate 11 includes first and second side surfaces S1 and S2 disposed on opposite sides and third and fourth side surfaces S3 and S4 disposed on opposite sides to each other, and the first and second side surfaces S1 , S2) is disposed adjacent to the third and fourth side surfaces S3 and S4. Each side surface S1 , S2 , S3 , and S4 of the substrate 11 is a vertical surface and may be each side surface of the semiconductor device 100 . Each side surface S1 , S2 , S3 , and S4 of the substrate 11 may be a lower side surface of the light emitting structure 20 or a side surface of the first conductive type semiconductor layer 21 .

The substrate 11 may have a top view or bottom view shape of a polygon. When the substrate 11 is viewed from a top view as shown in FIG. 1 , a first axis direction on a plane may be an X-axis direction, and a second axis direction may be a Y-axis direction orthogonal to the X-axis direction. The thickness direction or the height direction of the substrate 11 is a third axis direction, and the third axis direction may be a Z axis direction. When the length of the substrate 11 in the first axis direction is X1 and the length of the second axis direction is Y1, a relationship of X1=Y1 or Y1≥X1 may be obtained. X1 and Y1 of the substrate 11 may be 0.8 mm or more, for example, 1 mm or more. For example, since the substrate 11 constitutes the lower structure of the semiconductor device 100, the length X1 of the substrate 11 in the first axial direction and the length Y1 of the second axial direction of the semiconductor device 11 are It may be the length of the X-axis direction and the Y-axis direction of the device. Each of the lengths X1 and Y1 of the substrate 11 may be 0.8 mm or more, for example, 1 mm or more. The size of the substrate 1 may be, for example, X1×Y1 in the range of 800 μm to 2500 μm×800 μm to 2500 μm. As the size (X1×Y1) increases, the light output due to the increase in the light emitting area increases. can be increased A semiconductor device having such a large-area substrate 11 may be implemented as a high-output device, for example, a high-output LED. In such a high-power semiconductor device, it is important to minimize the decrease in the light emitting area of the light emitting structure 20 and secure a current flow or heat emission path. Embodiments are intended to provide a device for minimizing a decrease in light emitting area within the semiconductor device 100 and improving current flow and heat dissipation. The thickness of the semiconductor device 100 may be formed in a range of 130 μm or more, for example, 130 μm to 170 μm.

A semiconductor layer having at least one of a group III-V compound semiconductor and a group II-VI compound semiconductor may be formed on the substrate 11 . A plurality of layers may be stacked on the semiconductor layer. The growth equipment of the compound semiconductor layer is an electron beam evaporator, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma laser deposition (PLD), dual-type thermal evaporator sputtering, MOCVD ( metal organic chemical vapor deposition), etc., but is not limited thereto. The semiconductor layer may include at least one of a p-n junction structure, an n-p junction structure, an n-p-n junction structure, and a p-n-p junction structure according to a stack structure. The p is a p-type semiconductor layer, the n is an n-type semiconductor layer, the n-p junction or p-n junction may have an active layer, and the n-p-n junction or p-n-p junction may have at least one active layer between n-p or between p-n. . The substrate on which the semiconductor layer is grown may be a growth substrate or a light-transmitting substrate, and the substrate separately attached to the semiconductor layer may be a conductive or non-conductive substrate and may be made of a light-transmitting or non-transmitting material. In the embodiment, since the material of the substrate 11 is provided in the same series as the material of the semiconductor layer, generation of crystal defects in the semiconductor layer can be suppressed.

<Light-emitting structure>

The light emitting structure 20 is disposed on the substrate 11 and includes a plurality of semiconductor layers. The light emitting structure 20 includes a first conductive semiconductor layer 21, an active layer 22 disposed on the first conductive semiconductor layer 21, and a second conductive semiconductor layer disposed on the active layer 22 ( 23) may be included. The light emitting structure 20 may further arrange other layers above or/and below the above layers, but is not limited thereto. An upper surface area of the light emitting structure 20 may be smaller than a lower surface area. The area of the lower surface 11B of the light emitting structure 20 may be equal to or smaller than the area of the upper surface of the substrate 11 . Here, the area may be an area formed by the X-axis-Y-axis plane.

The first conductive semiconductor layer 21 may be disposed between the substrate 11 and the active layer 22 . The first conductive semiconductor layer 21 may be implemented with at least one of group III-V and II-VI compound semiconductors doped with a first conductive dopant. The first conductive semiconductor layer 21 is, for example, a semiconductor having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) can be made of material. The first conductive semiconductor layer 21 may include, for example, at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP, Si, Ge, The n-type semiconductor layer may be doped with an n-type dopant such as Sn, Se, or Te. The first conductive type semiconductor layer 21 may be disposed in a single layer or multiple layers. The first conductive type semiconductor layer 21 may have a superlattice structure in which at least two different layers are alternately disposed. The first conductive semiconductor layer 21 may be an electrode contact layer. The first conductivity-type semiconductor layer 21 may include a semiconductor of the same material as the substrate 11, thereby reducing or eliminating a difference in lattice constant with the substrate 11, thereby generating crystal defects. can block Crystal defects of the first conductive semiconductor layer 21 may be improved compared to a layer having a sapphire substrate. The first conductive type semiconductor layer 21 may be formed of a compound semiconductor different from that of the substrate 11 among group II to group VI compound semiconductors.

A semiconductor layer, for example, a buffer layer may be included between the substrate 11 and the light emitting structure 20 , and the buffer layer may be formed of at least one layer using Group II to Group VI compound semiconductors. The buffer layer includes a semiconductor layer using a group III-V compound semiconductor, for example, In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤ 1) may be implemented as a semiconductor material having a composition formula. For example, the buffer layer may be formed of any one of materials such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and ZnO. In the embodiment, the buffer layer may be removed by using the substrate 11, but is not limited thereto.

The active layer 22 may be disposed between the first conductive semiconductor layer 21 and the second conductive semiconductor layer 23 . The active layer 22 may include at least one of a single quantum well structure, a multiple quantum well structure, a quantum wire structure, and a quantum dot structure. The active layer 22 may include at least one of group III-V and II-VI compound semiconductor materials. In the active layer 22 , layers having different energy band gaps may be alternately disposed. The active layer 22 includes a well layer and a barrier layer, and the barrier layer may be formed of a semiconductor material having an energy band gap wider than that of the well layer.

In the active layer 22, the well layer is, for example, a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) can be placed. The barrier layer may be formed of, for example, a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). The well/barrier pairs may be, for example, InGaN/GaN, GaN/AlGaN, AlGaN/AlGaN, InGaN/AlGaN, InGaN/InGaN, GaAs/AlGaAs, InGaAs/GaAs, InGaP/GaP, InGaP/AlInGaP, InP /GaAs. The active layer 22 may selectively emit ultraviolet light, visible light, or infrared light, and for example, may emit ultraviolet light, blue light, green light, red light, white light, or infrared light.

A lower cladding layer (not shown) may be disposed between the active layer 22 and the first conductive type semiconductor layer 21 . The lower clad layer may include at least one of group III-V and group II-VI compound semiconductor materials, and may include, for example, the same material as or a different material from the substrate 11 . An upper clad layer (not shown) may be disposed on the active layer 22 and the second conductive semiconductor layer 23 . The upper clad layer may include at least one of group III-V and group II-VI compound semiconductor materials, and may include, for example, the same material as or a different material from the substrate 11 .

The second conductive semiconductor layer 23 is disposed on the active layer 22 and may be implemented with at least one of group III-V and II-VI compound semiconductors doped with a second conductive dopant. The second conductivity type semiconductor layer 23 may be selected from, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and the like. When the second conductivity is a p-type semiconductor, the second conductivity dopant includes a p-type dopant such as Mg or Ze. The second conductive semiconductor layer 23 may be formed as a single layer or multiple layers, but is not limited thereto.

As another example, the first conductive semiconductor layer 21 may be a p-type semiconductor layer, and the second conductive semiconductor layer 23 may be an n-type semiconductor layer. A first conductive semiconductor layer may be further disposed on the second conductive semiconductor layer 23, but is not limited thereto. Thus, the light emitting structure 20 may include, for example, at least one of a p-n junction, an n-p junction, an n-p-n junction, and a p-n-p junction structure by a stacked structure of a plurality of semiconductor layers.

The side surface 25 of the light emitting structure 20 may be formed as an inclined surface with respect to the Z-axis direction. The inclined side surface 25 of the light emitting structure 20 may change the critical angle of incident light, thereby improving light extraction efficiency. The side surface 25 of the light emitting structure 20 includes a side surface of a portion of the first conductive semiconductor layer 21, a side surface of the active layer 22, and a side surface of the second conductive semiconductor layer 23. .

The second conductive semiconductor layer 23 and the active layer 22 according to the embodiment may not have a via structure therein. Accordingly, the active layer 22 may provide a larger light emitting area than an active layer having a via structure. The lower surface area of the active layer 22 may be 75% or more, for example, 75% to 82% of the upper surface area of the substrate 11 . The lower surface area of the active layer 22 may be 75% or more, for example, 75% to 82% of the lower surface area of the first conductive semiconductor layer 21 . By providing the area of the active layer 22 at least 75% of the size of the semiconductor device, light output can be improved.

The light emitting structure 20 may be a region in which the first conductive semiconductor layer 21 , the active layer 22 , and the second conductive semiconductor layer 23 overlap each other in the Z-axis direction.

<Central area and first area of light emitting structure>

1 and 4, the light emitting structure 20 has a central region (Qx, Qy) and a first region (21A) around the central region (Qx, Qy) based on the Z-axis direction with respect to the plane. ) may be included. The center regions Qx and Qy may be regions where the center region Qx in the X-axis direction and the center region Qy in the Y-axis direction intersect. The central regions Qx and Qy may be regions protruding into the first region 21A. The central regions Qx and Qy may be central regions of the first conductive semiconductor layer ( 21 in FIG. 4 ), and may be regions protruding from the surface of the first region 21A in the Z-axis direction. The central regions Qx and Qy may include regions overlapping with the active layer ( 22 in FIG. 4 ) in the Z-axis direction. The central regions Qx and Qy may be internal regions of the first conductive type semiconductor layer 21 excluding the first region 21A in the Z-axis direction.

The first region 21A may be disposed around central regions Qx and Qy where the layers 21 , 22 , and 23 of the light emitting structure 20 overlap each other. The first region 21A is disposed around the central regions Qx and Qy of the first conductive type semiconductor layer 21 . The first area 21A may be disposed in a shape surrounding the central areas Qx and Qy along the circumferences of the central areas Qx and Qy. The first region 21A may be a bottom region in which upper portions of the second conductive semiconductor layer 23 , the active layer 22 , and the first conductive semiconductor layer 21 are mesa-etched. The first region 21A may be disposed outside the side surface 25 of the light emitting structure 20 . The first region 21A is a region having a height lower than the top surface height of the central region Qx and Qy around the central region Qx and Qy of the first conductive type semiconductor layer 21 . can The height of the first region 21A in the Z-axis direction is lower than the heights of the central regions Qx and Qy of the first conductive semiconductor layer 21 . The first region 21A may include a top surface lower than the top surface of the first conductive semiconductor layer 21 that contacts or faces the active layer 22 .

The first region 21 includes peripheral regions Q1, Q2, Q3, and Q4 having predetermined widths along a first axis direction opposite to each other and a second axis direction opposite to each other with respect to the central region Qx and Qy. can include The first region 21A includes peripheral regions Q1, Q2, Q3, Q3, and X directions of the first axis (X) and the second axis (Y) that meet each other along the outer circumference of the first conductive type semiconductor layer 21. Q4) may be included. 1, the first region 21A includes first and second peripheral regions Q1 and Q2 disposed on opposite sides in the X-axis direction and third and fourth peripheral regions disposed on opposite sides in the Y-axis direction. (Q3, Q4) may be included. The first and second peripheral regions Q1 and Q2 may be connected to the third and fourth peripheral regions Q3 and Q4. The corner area of the first area 21A is a common area between the peripheral areas Q1, Q2, Q3, and Q4 in different axial directions, for example, a common area between the first and third peripheral areas Q1 and Q3. , the common area of the first and fourth peripheral areas Q1 and Q4, the common area of the second and third peripheral areas Q2 and Q3, and the second and fourth peripheral areas Q2 and Q4 It may be a common area of . The corner region of the first region 21A may be a region from each vertex S5 , S6 , S7 , or S8 to the central region Qx or Qy of the first conductive type semiconductor layer 21 . Widths of the first, second, third, and fourth peripheral regions Q1, Q2, Q3, and Q4 may be the same as or different from each other. For example, the widths of the first and second peripheral regions Q1 and Q2 may be the same, and Widths of the third and fourth peripheral regions Q3 and Q4 may be equal to each other. Widths of the first and second peripheral regions Q1 and Q2 may be the same as or different from those of the third and fourth peripheral regions Q3 and Q4, and may vary depending on the size of the semiconductor device.

The length of the first region 21A in the first axial direction or the second axial direction is the length of the central regions Qx and Qy of the first conductive semiconductor layer 21 in the first axial direction or the second axial direction. Can be placed larger. The first region 21A may be formed to the length of one side surface S1 , S2 , S3 , and S4 of the first conductive type semiconductor layer 21 .

The surface of the first region 21A may be a flat surface without roughness or a rough surface with roughness. A semiconductor surface, for example, GaN, may be exposed in the first region 21A. The first region 21A may be a mesa etched region and may be formed by wet and dry etching processes.

Here, referring to FIG. 3 , the first region 21A of the first conductivity-type semiconductor layer 21 has a first depth T3 in the Z-axis direction from the upper surface of the second electrode layer 63 based on the X-axis. can have The first depth T3 is lower than the top surface of the active layer 22 and may have a depth of 2 μm or less, for example, 1.5 μm. If the first depth T3 is greater than the range, the light emitting area may decrease if the first angle R1 is fixed, or the first electrode layer 65 may be cut if the first angle R1 is increased. Also, when the first depth T3 is made deeper, the degree of improvement in current diffusion may be insignificant even if the depth of the first region 21A is further etched.

<First electrode>

As shown in FIGS. 1 and 4 , the first electrode 67 may be disposed on the first region 21A of the first conductive semiconductor layer 21 . The first electrode 67 may be disposed around the central region of the first conductive type semiconductor layer 21 in the X-axis direction and the Y-axis direction. The first electrode 67 may be disposed around the central regions Qx and Qy of the light emitting structure 20 in a first axis direction and a second axis direction. The first electrode 67 is disposed along the first and second peripheral regions Q1 and Q2 of the first region 21A to have a long length D2 in the first axial direction, and the third and fourth It may be disposed with a long length D1 in the second axial direction along the peripheral regions Q3 and Q4. That is, the first electrode 67 has long lengths D2 and D1 in the same axial direction as the axial direction of the first region 21A disposed in the first axis (X) direction and the second axis (Y) direction. ) can be placed with The lengths D2 and D1 of the first electrode 67 may be the same or different, and may vary depending on the size of the semiconductor device. As shown in FIG. 6 , the first electrodes 67 may be continuously arranged with a length D1 in the Y-axis direction.

The first electrodes 67 may be continuously disposed along the first region 21A of the first conductive semiconductor layer 21 located on opposite sides of the light emitting structure 20 . The first electrode 67 according to the embodiment is disposed in a region overlapping the first conductive semiconductor layer 21 in the Z-axis direction, for example, in the vertical direction, and overlaps the region of the active layer 22 in the Z-axis direction. It can be placed in an area that is not. The first electrode 67 may be disposed to overlap the first region 21A of the first conductive type semiconductor layer 21 in a vertical direction.

The first electrode 67 is disposed outside each side surface 25 of the light emitting structure 20 and may be connected to the first electrode layer 65 . The first electrode 67 supplies the current diffused through the first electrode layer 65 to the central regions Qx and Qy of the first conductive semiconductor layer 21 through the first region 21A. can The first conductive type semiconductor layer 21 may receive a uniformly distributed current through the first electrode 67 .

4 and 7, the first electrode 67 is disposed on the first region 21A between the central regions Qx and Qy and the outermost edge of the first conductive semiconductor layer 21. It can be. The first electrode 67 has long lengths D2 and D1 along the longitudinal direction of the first region 21A, for example, the X-axis direction or the Y-axis direction, and has vertices S5, S6, S7, and S8. can be separated from That is, the first electrodes 67 may be arranged in the form of line electrodes along the X-axis direction and the Y-axis direction of the first area 21A, and may be connected to each other at corner portions of the first area 21A.

The corner portion 67R of the first electrode 67 is disposed on the first regions 21A in different axial directions adjacent to the vertices S5, S6, S7, and S8, has a curved shape, and has a curved shape. , S6, S7, S8) may be spaced at the same interval. The light emitting structure ( 20) may be arranged in a rotationally symmetrical form with respect to the central axes (X0, Y0) of the Y-axis direction or the X-axis direction.

The first electrode 67 includes a non-metallic or metallic conductive material. The first electrode 67 includes a transparent or opaque conductive material. The first electrode 67 may be formed of a material different from that of the conductive layer 61 . The first electrode 67 may include at least one material selected from the group consisting of Cr, Ni, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Ti, Cu, and combinations thereof. there is. The first electrode 67 may be formed in a single layer or multiple layers. When the first electrode 67 is multi-layered, it may include a laminated structure of a contact layer/adhesive layer/conductive layer/adhesive layer, and the first layer may include, for example, Cr as a contact layer, and the conductive layer may include, for example, Cu having a thickness of 500 nm or more may be included. The first electrode 67 may be formed to a thickness thicker than the thickness of the conductive layer 61, and may have a thickness of 10 times or more, for example, 100 times or more of the thickness of the conductive layer 61. The first electrode 67 may be thick to improve adhesion between the semiconductor layer and the first electrode layer 65 and to conduct heat. The first electrode 67 may be formed to have a thickness twice or more thick than that of the first insulating layer 51 .

As another example of the first electrode 67, the adhesive layer in the multilayer structure may include at least one of metal oxide and metal nitride. The metal oxide or metal nitride may be indium tin oxide (ITO), ITO nitride (ITON), indium zinc oxide (IZO), IZO nitride (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), or IGZO. (indium gallium zinc oxide), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), ZnO, IrOx, RuOx, and NiO. can include

As shown in FIG. 4 , the distance D4 between the first electrodes 67 disposed on the first regions 21A opposite to each other in the Y-axis direction may have the same distance, and the center of the light emitting structure 20 They may be spaced apart larger than the lengths of the regions Qx and Qy.

<First electrode layer>

The first electrode layer 65 may cover the central region of the light emitting structure 20 and the upper region of the first region 21A, as shown in FIGS. 1 and 2 to 4 . As shown in FIG. 8, the first electrode layer 65 is the upper portion of the light emitting structure 20, the side surface of the light emitting structure 20, and the first opening 6 of the second insulating layer 55. An upper region of the first region 21A of the conductive semiconductor layer 21 is covered. The first electrode layer 65 may overlap the side surface 25 of the light emitting structure 20 and the first region 21 in the Z-axis direction. The first electrode layer 65 may be formed of a single layer or multiple layers made of a metal material. The first electrode layer 65 functions to reflect incident light, supply power and spread current, and may be defined as a reflective electrode layer or a diffusion layer. The first electrode layer 65 is from a group consisting of at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Cr, Ti, and Cu, or an optional combination thereof. It may contain at least one of selected materials. When the first electrode layer 65 is multi-layered, it includes a laminated structure including a reflective layer, a bonding layer, an adhesive layer, and a capping layer. The first electrode layer 65 may selectively laminate Ag, Al, Ni, Ti, or Au, for example, Ni/Ag/Ni/Ti/Au/Ti or Ni/Ag/Ni/Ti/Ni/Au. /Ti may have a layered structure. The thickness of the Au is 400 nm or more, for example, in the range of 500 nm to 900 nm, the Ag has a thickness smaller than the thickness of Au, but may be formed at 100 nm or more, and other layers are formed at 150 nm or less to prevent deterioration of adhesive force and light can improve the reflection efficiency. The first electrode layer 65 may include a metal (eg, Ag) different from the reflective metal of the second electrode layer 63, for example, Al, but is not limited thereto. 3 and 5, the first electrode layer 65 includes a reflective electrode layer 165 that reflects light and a capping layer 166 that electrically or physically protects the reflective electrode layer 165 on the reflective electrode layer 165. ), the reflective electrode layer 165 may include Ag or Al, and the capping layer 166 is disposed on the surface of the reflective electrode layer 165 and may include Au. Here, when the reflective electrode layer 165 has a stacked structure of Ag/Ni of Example 1 or Ni/Ag/Ni of Example 2 shown in FIG. 25, 90% of the wavelength of light emitted from the active layer 22 Or more, for example, may have a reflectance of 93% or more. Comparing the reflectance (R) may have a relationship of R _{Ag / Ni} > R _{Ni / Ag / Ni} , and the thickness of the Ag may have a range of 200 nm to 300 nm. The first electrode layer 65 may reflect most of the light that proceeds to the first electrode layer 65 among the light emitted from the active layer 22 . For example, since the first electrode layer 65 is disposed on the side surface 25 and the first region 21A of the first conductivity type semiconductor layer 21, Light loss in the first region 21A may be reduced and light extraction efficiency may be improved.

Here, as shown in FIGS. 3 to 5 and 8 , the first electrode layer 65 includes the second reflector 65A disposed on the side surface 25 of the light emitting structure 20 and the first conductive type semiconductor. A first reflector 65B disposed on the first region 21A of the layer 21 is included. The first reflector 65B overlaps the first region 21A in the Z-axis direction, and the second reflector 65A extends along the side surface 25 of the light emitting structure 20 in the Z-axis direction. may overlap with The first reflector 65B may reflect the light incident on the first region 21A of the first conductive semiconductor layer 21 without leakage. The second reflector 65A may reflect the incident light from the surface of the first insulating layer 51 positioned on the side surface 25 of the light emitting structure 20 . An outer surface of the second reflector 65A may have a stepped structure, and such a stepped structure may improve an adhesive area with another layer at an inclined portion. The surface of the first reflector 65B may have a stepped structure, and such a stepped structure may improve an adhesion area with other layers in a horizontal portion.

The first reflector 65B may be continuously formed along the first region 21A of the first conductive semiconductor layer 21 . The first reflector 65B may continuously or discontinuously contact the upper surface of the first region 21A of the first conductive type semiconductor layer 21 . The first reflector 65B has a contact portion 65C, and the contact portion 65C may contact the upper surface of the first region 21A of the first conductive semiconductor layer 21 . The contact portion 65C of the first reflector 65B may contact the upper and side surfaces of the first electrode 67 . The first reflector 65B may contact inner and outer sides of the first electrode 67 . The first reflector 65B may reflect light traveling to a peripheral area of the first electrode 67 . Accordingly, the first electrode 67 may not be exposed upward through the first electrode layer 65 . The first electrode layer 65 may include the first electrode 67 .

The first electrode 67 and the first electrode layer 65 according to the embodiment may be defined as a first electrode structure. The first electrode structure may be provided as a structure of a reflective layer that contacts the first region 21A of the first conductive semiconductor layer 21 and covers most of the region of the light emitting structure 20 .

FIG. 13 is another example of the first electrode layer 65. The reflective electrode layer 165 and the capping layer 166 of the first electrode layer 65 form the first region 21A of the first conductive semiconductor layer 21. can be contacted. In this case, an end of the second reflecting portion 65 of the first electrode layer 65 may extend outward of the first electrode 67 .

<Second Electrode Structure>

The second electrode structure may include an electrode (layer) disposed on the light emitting structure 20 and electrically connected to the second conductive semiconductor layer 23 . The conductive layer 61 may be disposed between the second electrode layer 63 and the light emitting structure 20 based on the Z-axis direction. The conductive layer 61 may contact the upper surface of the light emitting structure 20 . The conductive layer 61 may contact the upper surface of the second conductive semiconductor layer 23 . The conductive layer 61 may make ohmic contact with the second conductive semiconductor layer 23 .

The conductive layer 61 includes a non-metallic or metallic conductive material. The conductive layer 61 includes a transparent or opaque conductive material. The conductive layer 61 may include at least one of metal oxide and metal nitride. The conductive layer 61 may include indium tin oxide (ITO), ITO nitride (ITON), indium zinc oxide (IZO), IZO nitride (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), and IGZO. (indium gallium zinc oxide), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), ZnO, IrOx, RuOx, and NiO. can include The conductive layer 61 includes at least one material selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Cr, Ti, Cu, and combinations thereof. can include The conductive layer 61 may be formed in a structure including a single layer or multiple layers. The conductive layer 61 may be disposed to a thickness of 10 nm or less, for example, 1 nm to 10 nm. When the thickness of the conductive layer 61 is less than 1 nm, operating voltage characteristics may deteriorate due to high sheet resistance, and when the thickness of the conductive layer 61 is less than 10 nm, light transmission characteristics may deteriorate and light extraction efficiency may decrease. The conductive layer 61 may have a thickness of, for example, 1 nm to 5 nm or less, and electrical and optical characteristics may be further improved at this thickness. When the conductive layer 61 is made of a light-transmitting material, light transmitted through the conductive layer 61 may be reflected by the second electrode layer 63 . The conductive layer 61 may be included in the second electrode layer 63 or may be removed.

The second electrode layer 63 may be disposed on the light emitting structure 20 , and the first electrode layer 65 may be disposed on the second electrode layer 63 . The second electrode layer 63 may be disposed between the first electrode layer 65 and the upper surface of the light emitting structure 20 based on the Z-axis direction. The second electrode layer 63 may be disposed between the conductive layer 61 and the first electrode layer 61 in the Z-axis direction. The second electrode layer 63 may be electrically connected to the second conductive semiconductor layer 23 . The first electrode layer 65 may be electrically connected to the first conductive semiconductor layer 21 . The second electrode layer 63 may be disposed in an area that does not overlap with the side surface 25 of the light emitting structure 20 in the Z-axis direction.

The second electrode layer 63 may be formed of a single layer or multiple layers of a metal material. The second electrode layer 63 may be defined as a reflective electrode layer or a current diffusion layer that reflects incident light and supplies power. The second electrode layer 63 is from a group consisting of at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Cr, Ti, and Cu, or an optional combination thereof. It may contain at least one of selected materials. When the second electrode layer 63 is multi-layered, it includes a laminated structure selectively including a reflective layer, a bonding layer, an adhesive layer, and a capping layer. The second electrode layer 63 has, for example, a stacked structure selectively using Al, Ag, Ni, Ti, and Au, and may include a stacked structure of Ag/Ni/Ti/Ni/Au/Ti, and the Ag and Each thickness of Au is formed to be 200 nm or more and the other layers are formed to be less than 100 nm to prevent degradation of adhesion and improve light reflection efficiency. Here, the Ni/Ti pair may be formed in one pair or two or more pairs.

An area of the upper surface of the second electrode layer 63 in the X-axis-Y-axis plane may have a smaller area than the area of the upper surface of the light emitting structure 20 . An upper surface area of the second electrode layer 63 may be smaller than an upper surface area of the conductive layer 61 . A side surface of at least one or both of the conductive layer 61 and the second electrode layer 63 may be formed as an inclined surface. An edge of the conductive layer 61 may extend more outward than an edge of the second electrode layer 63 . That is, the area of the conductive layer 61 on the X-axis-Y-axis plane may be larger than that of the second electrode layer 63 .

The lower surface area of the second electrode layer 63 is smaller than the upper surface area of the active layer 22 and may be 90% or more of the upper surface area of the active layer 22 . Since the second electrode layer 63 covers 90% or more of the upper surface of the active layer 22, light reflection efficiency can be improved. Since the second conductive semiconductor layer 23 does not have a separate via structure, the size of the second electrode layer 63 can be 90% or more of the size of the active layer 22 . The size may be calculated as a length in the first axial direction×an area in the second axial direction. When the area of the lower surface of the first conductive semiconductor layer 21 is a, the area of the upper surface of the active layer 22 is b, and the area of the lower surface of the second electrode layer 63 is c, then a>b>c can have a relationship.

<First insulating layer>

The first insulating layer 51 may be disposed between the first electrode layer 65 and the second electrode layer 63 in the Z-axis direction. The first insulating layer 51 may be formed in a single layer or multiple layers using a dielectric material. The first insulating layer 51 includes an insulating material or an insulating resin formed of at least one of oxide, nitride, fluoride, and sulfide having at least one of Al, Cr, Si, Ti, Zn, and Zr. The first insulating layer 51 may be selectively formed from, for example, SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , and TiO ₂ .

As another example, the first insulating layer 51 may be formed of a reflective layer having a stacked structure of different dielectric layers. The reflective layer may be formed of a distributed Bragg reflector (DBR) structure, and the distributed Bragg reflector structure includes a structure in which two dielectric layers having different refractive indices are alternately disposed, for example, a SiO ₂ layer. , a Si ₃ N ₄ layer, a TiO ₂ layer, an Al ₂ O ₃ layer, and a different MgO layer, respectively.

The first insulating layer 51 is disposed between the second electrode layer 63 and the first electrode layer 65, and the first conductive semiconductor layer 21 and the second conductive semiconductor layer 23 And it may be disposed on the side surface 25 of the active layer 22. The first insulating layer 51 covers the second electrode layer 63 , the conductive layer 61 and the light emitting structure 20 . The first insulating layer 51 may be disposed on the second electrode layer 63 to prevent penetration of moisture and electrically insulate the first electrode layer 65 . The outer portion 51A of the first insulating layer 51 may be disposed on the first region 21A of the first conductive semiconductor layer 21 . The outer portion 51A of the first insulating layer 51 may be disposed in a region between the side surfaces 25 of the light emitting structure 20 and the first electrode 67 .

Here, the outer portion 51A of the first insulating layer 51 is disposed on the first region 21A of the first conductive semiconductor layer 21, as shown in FIGS. 3 and 5, and the open area ( 7) can have. The open area 7 may expose the upper surface of the first area 21A. A portion of the first electrode layer 65 may protrude through the open area 7 and contact the surface of the first area 21A. For example, the contact portion 65C of the first electrode layer 65 may contact the upper surface of the first region 21A, that is, the first conductive semiconductor layer 21 . The contact portion 65C may be disposed in the X-axis direction and the Y-axis direction along the first region 21A of the first conductive type semiconductor layer 21 . The contact portion 65C may be electrically connected to the first conductive type semiconductor layer 21 . The contact portion 65C may cover the circumference of the first electrode 67 disposed in the X-axis direction and the Y-axis direction. The first electrode layer 65 comes into contact with the first conductivity-type semiconductor layer 21 and the first electrode 67 through the contact portion 65C, and has a high contact with the first conductivity-type semiconductor layer 21. It can be connected with contact resistance, so the input current can be spread.

The contact portion 65C of the first electrode layer 65 may be spaced apart from the side surface 25 of the light emitting structure 20 by the outer portion 51A of the first insulating layer 51 . Accordingly, electrical interference between the contact portion 65C and the second conductive type semiconductor layer 23 can be blocked and moisture permeation can be suppressed.

<Second insulating layer>

As shown in FIGS. 2 to 5 , the second insulating layer 55 is partially disposed between the first electrode layer 65 and the plurality of pads 71 and 81 . The second insulating layer 55 has a first opening 5 between the first pad 71 and the first electrode layer 65, and the first pad 71 formed by the first opening 5 ) and the electrical connection path of the first electrode layer 65, except for the region can be insulated. The second insulating layer 55 has a second opening 6 between the second pad 81 and the first and second electrode layers 65 and 67, and the second opening 6 An area other than an electrical connection path between the two pads 81 and the second electrode layer 67 may be insulated. The second insulating layer 55 may overlap the first and second pads 71 and 81 and the first and second electrode layers 65 and 67 in the Z-axis direction. The second insulating layer 55 has an outer portion 55A, and the outer portion 55A may be disposed on the first reflective portion 65B and the second reflective portion 65A of the first electrode layer 65. there is. The outer portion 55A of the second insulating layer 55 may be disposed on the first reflection portion 65B of the first electrode layer 65 in the first region 21A. A part of the second insulating layer 55 may be in contact with the first insulating layer 51 to block electrical interference between different metals. The outer portion 55A of the second insulating layer 55 may contact the outer portion 51A of the first insulating layer 51 . The second insulating layer 55 may be formed in a single layer or multiple layers using a dielectric material. The second insulating layer 55 includes an insulating material or an insulating resin formed of at least one of oxide, nitride, fluoride, and sulfide having at least one of Al, Cr, Si, Ti, Zn, and Zr. The second insulating layer 55 may be formed selectively from, for example, SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , and TiO ₂ . The second insulating layer 55 may be made of the same material as the first insulating layer 51 or a different material.

<pad>

A plurality of pads 71 and 81 may be disposed on the first electrode layer 65 . The second insulating layer 55 may be disposed between the first electrode layer 65 and the pads 71 and 81 . The plurality of pads 71 and 81 may include a first pad 71 and a second pad 81 . At least one or both of the first pad 71 and the second pad 81 may be disposed on the first electrode layer 65 .

Each of the first and second pads 71 and 81 may overlap the active layer 22 in the Z-axis direction. The first pad 71 and the second pad 81 may be disposed to overlap the light emitting structure 20 in the Z-axis direction. The first pad 71 may be disposed to overlap the first electrode layer 65 and the second electrode layer 63 in the Z-axis direction, that is, in the vertical direction. The second pad 81 may be disposed to overlap the first electrode layer 65 and the second electrode layer 63 in the Z-axis direction, that is, in the vertical direction. When the sizes of the first pad 71 and the second pad 81 are the same, the problem of concentration of generated heat can be improved. An identification unit ( 83 in FIG. 1 ), for example, a cathode mark, may be provided on the second pad 81 . In this case, when the first and second pads 71 and 81 are bonded, the bonding directions of the cathode and anode can be easily distinguished through the identification unit 83 .

A top area of the first pad 71 may be equal to or smaller than a bottom area. The first pad 71 may have a vertical side or an inclined side. The upper surface area of the second pad 81 may be equal to or smaller than the bottom area. The second pad 81 may have a vertical side or an inclined side.

The first pad 71 and the second pad 81 are spaced apart from each other on the same horizontal plane, and a spaced area 75 is disposed between the first pad 71 and the second pad 81 . The first pad 71 and the second pad 81 may be disposed on the first electrode layer 65 and the second electrode layer 63 . The first pad 71 is electrically connected to the first electrode layer 65 , and the second pad 81 is electrically connected to the second electrode layer 63 . The second insulating layer 55 is disposed below the first pad 71 and the second pad 81 . The second insulating layer 55 may be disposed in a region between the first pad 71 and the first electrode layer 65 and in a region between the second pad 81 and the first electrode layer 65. can

The first pad 71 and the second pad 81 according to the embodiment may include a eutectic bonding or solder bonding material. The first pad 71 and the second pad 81 are made of titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum (Ta), or platinum (Pt). ), at least one of tin (Sn), silver (Ag), and phosphorus (P), or a selective alloy thereof, and may be formed in a single layer or multiple layers. The first pad 71 and the second pad 81 may have the same layer structure. When the first pad 71 and the second pad 81 have a multi-layer structure, they may include an adhesive layer and a bonding layer, the bonding layer may contain one or more pairs of Ni and Ti, and the bonding layer may contain Au and At least one or all of Sn may be included. The first pad 71 and the second pad 81 may provide a thickness of 1 μm or more, for example, in a range of 1.5 μm to 7 μm, so that bonding force and heat transfer capability may be improved within the thickness range.

As shown in FIGS. 1 , 2 and 4 , a plurality of first openings 5 of the second insulating layer 55 are spaced apart from each other under the first pad 71 . The first opening 5 may have a circular or polygonal shape in a top view, and for example, may be formed in a polygonal shape to consider the contact area. The plurality of first openings 5 may be disposed to overlap the first pad 71 in a vertical direction. The first pad 71 includes a plurality of first protrusions 71A at a lower portion, and each of the first protrusions 71A may be disposed in the first opening 5 . The first protrusion 71A protrudes from the first pad 71 toward the first electrode layer 65, and may have a wide upper part and a narrow lower part. The first protrusion 71A may contact and electrically connect to the first electrode layer 65 . The bottom view of the first protrusion 71A may have a polygonal shape or a circular shape, for example, a polygonal shape. 1, 3 and 5, the first pad 71 has a plurality of first concave portions 5B concavely recessed with respect to an upper surface or a horizontal surface, and each first concave portion 5B is It may be disposed in an area corresponding to the first opening 5 . Each of the first concave portions 5B may have a polygonal shape in a top view. The plurality of first concave portions 5B may improve bonding efficiency during bonding of the first pad 71 .

The second opening 6 of the second insulating layer 55 may be formed through the second insulating layer 55 , the first electrode layer 65 and the first insulating layer 51 . A plurality of the second openings 6 may be disposed under the second pad 81 and spaced apart from each other. The second opening 6 is disposed on the second electrode layer 63 and may be disposed to overlap the second pad 81 in a vertical direction. The second opening 6 may have a circular shape or a polygonal shape in a top view, for example, may be formed in a circular shape. A second insulating layer 55 may be disposed around the second opening 6 . The number of the first openings 5 and the second openings 6 may be the same. The second pad 81 includes a plurality of second protrusions 81A at a lower portion, and each of the second protrusions 81A may be disposed in each of the second openings 6 . Each of the second protrusions 81A may have a wide upper portion and a narrow lower portion. The second protrusion 81A may protrude toward the first electrode layer 65 and contact and electrically connect to the second electrode layer 63 . The second protrusion 81A may have a bottom view shape of a circular shape or a polygonal shape, for example, a circular shape. 1 and 9, the second pad 81 has a plurality of second concave portions 6B concavely recessed with respect to an upper surface or a horizontal surface, and each second concave portion 6B is It may be disposed in an area corresponding to the second opening 6 . The second concave portion 6B may have a circular shape having different radii in a top view shape, and may have a gradually deeper depth toward the inner center. The plurality of second concave portions 6B may improve bonding efficiency during bonding of the second pad 81 . The depth of the second concave portion 6B may be deeper than that of the first concave portion 5B.

The embodiment provides a large reflection area of the first electrode layer 65 to improve light reflection efficiency. The first electrode layer 65 may provide a reflective area of 90% or more on the X1-Y1 plane. The first electrode layer 65 may be disposed on an upper region of the light emitting structure 20 , a side region of the light emitting structure 20 , and the first region 21 . The first electrode layer 65 may reflect most of the incident light toward the substrate 11 . For example, the area of the lower surface of the first conductive semiconductor layer 21 is a, the area of the upper surface of the active layer 22 is b, the area of the lower surface of the second electrode layer 63 is c, When the area of the lower surface of the electrode layer 65 is d, it may have a relationship of d>a>b>c. Here, the lower surface area of the first electrode layer 65 may be the sum of the lower surface areas of the first and second reflectors 65B and 65A. Since the area of the lower surface of the first electrode layer 65 is wide, light traveling in the direction of the first electrode layer 65 can be effectively reflected. In addition, the first electrode layer 65 is in contact with the first electrode 67 disposed on the first region 21A in the different axial direction, so that the first conductivity type semiconductor layer 21 through the first electrode 67 ), the current can be spread and supplied to the entire area.

In the embodiment, the first electrode 67 is electrically connected to the first conductive semiconductor layer 21 by disposing the first electrode 67 between the first reflective portion 65A and the first region 21A of the first electrode layer 65, By removing the via structure in the central region of the light emitting structure 20, a reduction in the light emitting area can be reduced, an increase in driving voltage can be suppressed, and a diffused current supply and internal quantum efficiency can be improved. To this end, as shown in FIG. 5 , the first electrode 67 may be spaced apart from the side surface 25 and the outermost edge of the first conductive semiconductor layer 21 . An upper surface of the first region 21A of the first conductive semiconductor layer 21 may have a first width E1, and the first width E1 may include an outer region E6 and an inner region E2. can be distinguished. The first width E1 may be formed in a range of 50 μm or more, for example, 50 μm to 65 μm for the light emitting area, and if the first width E1 is larger than the above range, the light emitting area may decrease or the yield of chips in the wafer may decrease. The outer region E6 is a size for separating individual chips, and may have a width of 30 μm or less, for example, 5 μm to 30 μm, and may be a region in which the insulating layers 51 and 55 are removed. Accordingly, the first electrode 67 and the first electrode layer 65 are spaced apart from the outermost edge of the first conductive semiconductor layer 21 to protect the chip when separated into individual devices. The inner region E2 may be a region in which the first electrode 67 and the first reflector 65B of the first electrode layer 65 are disposed. Here, the width E5 of the first electrode 67 may be formed in a range of 7% to 11% of the first width E1, and the contact portion 65C disposed in the open area 7 The width E4 of may be formed in a range of 10% to 15% of the first width E1. When the width E5 of the first electrode 67 is larger than the above range, the reflective area of the contact portion 65C may be reduced, and when the width E5 is smaller than the above range, the reflective area of the contact portion 65C may be increased. The width E4 of the contact portion 65C of the first reflector 65B may be formed in a range of 5 μm or more, for example, 5 μm to 10 μm. The width E5 of the bottom of the first electrode 67 may be equal to or smaller than the width E4 of the contact portion 65C, for example, in a range of 4 μm to 7 μm. When the width E5 is less than 4 μm, the contact area with the first conductivity-type semiconductor layer 21 is reduced so that the operating voltage may increase. This may reduce the light extraction efficiency.

As shown in FIG. 7, the lengths D1 and D2 of the first electrode 67 in the X-axis direction or the Y-axis direction are 1/2 or more of X1 and Y1, for example, 4/5 or more, and X1 > D1, It may have a relationship of Y1>D2. The contact portion 65C of the first electrode 67 and the first electrode layer 65 may contact the upper surface of the first region 21A of the first conductive semiconductor layer 21 . The length of the contact portion 65C in the X-axis direction or the Y-axis direction may be 8/10 of X1 and Y1, for example, 9/10 or more, and may be smaller than X1 and Y1.

When the first region 21A of the first conductive semiconductor layer 21 is 100%, the contact area of the first electrode 67 to the area of the first region 21A is 30% or less, for example, 5 % to 30%. If the contact area of the first electrode 67 exceeds the above range, the reflection area decreases and the improvement of the driving voltage may be insignificant. If it is smaller than the above range, the contact resistance with the first conductive semiconductor layer 21 Increased problems may occur. The embodiment can improve the contact area of the first electrode 67 compared to a structure in which the continuously disposed first electrode 67 is discontinuously or dispersedly disposed, and the light emitting structure 20 Current injection efficiency can be improved.

The contact area of the first electrode 67 may be disposed in a range of 5.4% or less, for example, 1.5% to 5.4% of the area of the lower surface of the first conductive semiconductor layer 21 . When the first electrode 67 is larger than the above range, improvement in forward voltage may be insignificant compared to a decrease in reflection area.

The embodiment can improve bonding efficiency according to the number and contact area of the protrusions 71A and 81A disposed in the plurality of pads 71 and 81 and reduce metal deformation due to pad contact. To this end, as shown in FIG. 1 , the first pad 71 is disposed in a range in which the length X2 in the first axial direction is twice or more, for example, 2.2 to 3 times the length Y2 in the second axial direction. It can be. The second pad 81 may have a length X2 in the first axial direction that is twice or more, for example, 2.2 to 3 times greater than the length Y3 in the second axial direction. Since the first pad 71 and the second pad 81 are arranged in the second axial direction, the length X2 of the first pad 71 and the second pad 81 in the first axial direction is It is more than twice as large as the lengths (Y2, Y3) in the axial direction, thereby securing a heat transfer surface area and reducing mutual interference.

The length X2 of the first and second pads 71 and 81 in the first axial direction may be greater than or equal to 0.8 of the length X1 of the substrate 11 in the first axial direction, for example, in the range of 0.82 to 0.88. . Lengths Y2 and Y3 of the first and second pads 71 and 81 in the second axial direction may be 0.38 or less of the length Y1 of the second axial direction of the substrate 11, for example, in the range of 0.30 to 0.34. can The first pad 71 and the second pad 81 can secure a sufficient heat dissipation surface area and reduce thermal interference between the first pad 71 and the second pad 81.

The distance G1 between the first pad 71 and the second pad 81 is 3.5 times the lengths Y2 and Y3 of the first pad 71 and the second pad 81 in the second axial direction. Below, for example, it may have a range of 1.2 times to 3.5 times. When the distance G1 between the first and second pads 71 and 81 is greater than the above range, a heat concentration problem may occur in an area between the first and second pads 71 and 81. If it is less than the above range, electrical or physical interference problems may occur during bonding.

The number of the first protrusions 71A and the number of the second protrusions 81A may be the same. Each of the first and second protrusions 71A and 81A may be at least three or more, for example, in the range of 3 to 12, and if the number is less than the above number, heat dissipation may be difficult and the bonding portion may fall off. If the number of is exceeded, improvement in heat dissipation ability may be insignificant. Each of the first and second protrusions 71A and 81A may be the same or different in number. A bottom area of each of the first protrusions 71A may be larger than a bottom area of each of the second protrusions 81A. For example, when the distance between the first protrusion 71A and the first electrode 67 is d1 and the distance between the second protrusion 81A and the conductive layer 61 is d2, d1> Since it has a relationship of d2, the bottom area of the first protrusion 71A may be larger than the bottom area of the second protrusion 81A. Accordingly, an effect of reducing a current moving distance to the first electrode 67 may be provided.

The sum of the total bottom areas of the first protrusions 71A may be 3% or more, eg, 4% to 6.5% of the top surface area of the first pad 71 . The first protrusion 71A may be disposed within 1% or less of the area of the upper surface of the first pad 71, for example, in a range of 0.5% to 1%. Looking at the bottom of the first protrusion 71A, the length B1 in the first axial direction is 50 μm or more, for example, in the range of 55 μm to 65 μm, and the length B2 in the second axial direction is 30 μm or more. For example, it may have a range of 35 μm to 45 μm. If the bottom area of the first protrusions 71A is smaller than the above range, a problem of metal deformation occurring in the contact area between the first protrusions 71A and the first electrode layer 65 may occur when a high current is driven. can Due to the metal deformation, electrical reliability and heat dissipation characteristics of the second pad 81 may be deteriorated.

The total sum of the bottom areas of the second protrusions 81A may be 2% or more of the top surface area of the second pad 81, for example, 2% to 3.5%. The bottom area of each second protrusion 81A may be 1% or less of the top surface area of the second pad 81, for example, in a range of 0.3% to 1%. Looking at the width of the bottom of the second protrusion 81A, the length C1 in the first or second axis direction may be 35 μm or more, for example, 35 μm to 45 μm. When the bottom area of the second protrusions 81A is smaller than the above range, metal deformation occurs in the contact area between the second protrusions 81A and the second electrode layer 63 when driven with a high current. It can be. Due to the metal deformation, electrical reliability and heat dissipation characteristics of the second pad 81 may be deteriorated.

Referring to FIG. 1 , the first protrusion 71A has a first distance B7 from the side of the first pad 71 in the X-axis direction, and faces the second pad 81 in the Y-axis direction. It may have a second distance B5 from the inner surface and a third distance B6 from the outer surface. The first interval B7 may have a range of 1.5 times or more, for example, 1.5 to 2.5 times the second interval B5 or the third interval B6. Here, the second interval B5 and the third interval B6 may be equal to each other or the second interval B5 may be greater than the third interval B6 by a difference of 5 μm or less. The fourth interval B3 between the first protrusions 71A in the X-axis direction may be larger than the first interval B7, for example, may have a difference of 5 μm or more. The fifth distance B4 between the first protrusions 71A in the Y-axis direction may be smaller than the fourth distance B3, and for example, the fifth distance B4 may be 1/1.5 or less of the fourth distance B3. there is. Here, it may have a relationship of B4>B5≥B6. Due to the distribution of the first protrusions 71A, a problem of current concentration in the center area of the first pad 71 and the area between the first pad 71 and the second pad 81 can be reduced.

The second protrusion 81A has a first distance C4 from the side surface of the second pad 81 in the X-axis direction, and the inner surface facing the first pad 71 in the Y-axis direction and the second protrusion 81A. It may have a distance C7 and a third distance C5 from the outer surface. The first interval C4 may have a range of twice or more, for example, 2.2 to 3 times the second interval C7 or the third interval C5. Here, the second interval C7 and the third interval C5 may be equal to each other or the second interval C7 may be larger than the third interval C5 by a difference of 15 μm or less. The fourth distance C2 between the second protrusions 81A in the first axis direction may be greater than the first distance C4, for example, may have a difference of 10 μm or more. The fifth distance C3 between the second protrusions 81A in the Y-axis direction may be smaller than the fourth distance C2, and for example, the fifth distance C3 may be 1/2 or less of the fourth distance C2. . Due to the distribution of the second protrusions 81A, a problem of current concentration in the center area of the second pad 81 and the area between the first pad 71 and the second pad 81 can be reduced.

The embodiment can prevent the problem of breaking the metal layer according to the inclined angle of the side surface 25 of the light emitting structure 20 . To solve this problem, on the side surface 25 of the light emitting structure 20, as shown in FIG. 11, a first insulating layer 51 / first electrode layer 65 / second insulating layer 55 may be stacked. Here, when the inclined side surface 25 has a first angle R1 with respect to the X-axis, the thickness change rate of the first electrode layer 65 disposed on the first insulating layer 51 may be small. In this case, the impact transmitted to the first electrode layer 65 may be alleviated by the thermal expansion difference between the first insulating layer 51 and the second electrode layer 63 . The first angle R1 may range from 30 degrees to 40 degrees, and when it is greater than the first angle R1, that is, as shown in FIG. 12, when the inclined side surface has a second angle R2, A problem in which the first electrode layer 65 is not properly disposed and disconnected may occur in the partial area A1 of the inclined side surface. When such a disconnection problem occurs, electrical characteristics and thermal characteristics of the first electrode layer 65 may be deteriorated. In addition, when the inclined side surface 25 is smaller than the first angle R1, there is a problem in that the light emitting area is reduced, and the degree of improvement of the breakage of the first electrode layer 65 may be insignificant.

Since the semiconductor device 100 according to the embodiment is manufactured using the semiconductor substrate 11, the light output and external quantum efficiency of the semiconductor device according to the embodiment of FIG. 22 are improved in proportion to the forward current density. It can be seen that the internal quantum efficiency is increased. In this case, the comparative example is an LED having a sapphire substrate, and it can be seen that the light output is lower than that of the embodiment. It can be seen that the semiconductor device 100 having the semiconductor substrate 11 has a reduced current droop compared to the comparative example having the sapphire substrate, as in the embodiment of FIG. 23 . It can be seen that the semiconductor device 100 having the semiconductor substrate 11 has improved thermal droop compared to the device having the sapphire substrate, as in Examples 1 and 2 shown in FIG. 24 . Examples 1 and 2 show the difference in heat drop according to the difference between the first electrodes. Therefore, the semiconductor device according to the embodiment solves the problem of heat drop and current drop by the structure of the substrate, the first electrode of the outer contact portion of the first conductive semiconductor layer, and the first and second electrode layers, and is a high-output device. For example, LEDs may be provided.

Even if the first electrode 67 is in contact with each side surface S1 , S2 , S3 , and S4 of the first conductive type semiconductor layer 21 in the first region 21A, the operating voltage is increased. It is not large, and light output according to the increase in the reflection area can be improved. In this case, if the sum of the contact areas of the first electrode 67 exceeds a maximum of 5.4% of the chip size or the area of the upper surface of the semiconductor substrate 11 or the area of the lower surface of the first conductive type semiconductor layer 21, reflection Light output may decrease as the area decreases, and if the contact area is less than 1.5%, forward voltage may greatly increase due to the decrease in the contact area.

As a value obtained by measuring the electrical characteristics of the semiconductor device according to the embodiment, in the case of testing the forward current (Vf3) and the output (P0) with a driving current of 350 mA, the first When the first electrodes 67 are continuously arranged in a line shape along the area 21A (100%), the forward driving voltage by the first electrodes is stable at 3.3±0.5V, and the light output of the first electrodes 67 is stable. It can be seen that as the area of the electrode layer 65 increases, it appears to be 450 (mW) or more.

14 is a diagram illustrating a semiconductor device according to a second embodiment. In describing the second embodiment, the same parts as the first embodiment will be referred to the description of the first embodiment.

Referring to FIG. 14, the first electrodes 67A and 67B disposed on opposite sides in the first axis direction based on the center region (Qx, Qy) of the light emitting structure 20 are on opposite sides in the second axis direction. It is disposed discontinuously with the disposed first electrodes 67C and 67D. The first electrodes 67A and 67B in the first axis direction are spaced apart from the first electrodes 67C and 67D in the second axis direction, and the spaced distances D18 and D19 are the vertices S5, S6 and S7. , S8). The lengths X7 and Y7 of the first electrodes 67A, 67B, 67C, and 67D may be the same as or different from each other, and may have a length of 55% or more of X1 or Y1, for example, 70% or more. The first electrodes 67A, 67B, 67C, and 67D may be disposed in areas outside the corner areas Q1-Q3, Q1-Q4, Q2-Q3, and Q2-Q4 of the first area 21A. The lengths of the first electrodes 67A, 67B, 67C, and 67D may be shorter than the lengths of the center regions Qx and Qy of the light emitting structure 20 . The first electrodes 67A, 67B, 67C, and 67D have long lengths in each axial direction and are disposed in areas other than corner areas, so that an increase in forward voltage can be suppressed, a diffused current can be supplied, and a reflection area It is possible to improve the reflection efficiency according to the increase of .

As another example, a plurality of first electrodes 67A, 67B, 67C, and 67D may be arranged at equal intervals in each of the axial regions of the first region 21A. When the first electrodes are disposed at equal intervals, a current dispersing effect may be provided and a reflection area may be increased.

15 is a diagram illustrating a semiconductor device according to a third embodiment. In describing the third embodiment, the same parts as the first embodiment will be referred to the description of the first embodiment.

Referring to FIG. 15 , the first electrodes 68 disposed around the center regions Qx and Qy of the light emitting structure 20 are disposed in a continuous line shape. The first electrode 68 may be disposed in corner regions Q1-Q3, Q1-Q4, Q2-Q3, and Q2-Q4 of the first region 21A where the first axial direction and the second axial direction meet. there is. The first electrode 68 includes a contact area 68A and a non-contact area 68B with respect to the line pattern, the contact area 68A is in contact with the first area 21A, and the non-contact area ( 68B) may be spaced apart from the first area 21A. In the first electrode 68, the non-contact area 68B includes an area spaced apart from the vertices S5, S6, S7, and S8 of the first area 21A by a predetermined distance D28, and the corner area (Q1-Q3, Q1-Q4, Q2-Q3, Q2-Q4). Here, the outer portion 51A of the first insulating layer 51 may be disposed under the non-contact area 68B to block contact with the first area 21A. By separating the non-contact area 68B of the first electrode 68 from the corner areas Q1-Q3, Q1-Q4, Q2-Q3, and Q2-Q4, the problem of current concentration near the vertex can be suppressed. there is.

16 is a modified example of the embodiment, in which the number of protrusions of the first pad 71 and the second pad 81 is modified.

Referring to FIG. 16 , two or more protrusions 71A of the first pad 71 may be arranged in a row in the X-axis direction. Two or more protrusions 81A of the second pad 81 may be arranged in a row in the X-axis direction. The distance B3 between the first protrusions 71A of the first pad 71 may have the same distance. The distance B3 between the second protrusions 81A of the second pad 81 may be wider than the distance B3 between the first protrusions 71A of the first pad 71 and may be equal to each other.

Referring to FIG. 17 , two or more protrusions 71A of the first pad 71 may be arranged in two rows in the X-axis direction. Two or more protrusions 81A of the second pad 81 may be arranged in two rows in the X-axis direction.

Any one of the first protrusions 71A of the first pad 71 may be disposed in the center area of the first pad 71 . Any one of the second protrusions 81A of the second pad 81 may be disposed in the center area of the second pad 81 . Here, the center area may be an area having the same distance (B3, C2) from adjacent protrusions.

Referring to FIG. 18 , the first electrode layer 65 may include a plurality of branch electrodes 69, and the plurality of branch electrodes 69 may include a first region of the first conductive semiconductor layer 21. It may protrude from 21A to the central region of the first conductive type semiconductor layer 21 . The branch electrode 69 may overlap a region 21C between the first pad 71 and the second pad 81 in the Z-axis direction. The plurality of branch electrodes 69 may extend inward or toward the central region through first regions 21A opposite to each other. The plurality of branch electrodes 69 may contact the first conductive type semiconductor layer 21 . The plurality of branch electrodes 69 are regions 75 between the first pad 71 and the second pad 81, and the gap between the first pad 71 and the second pad 81 It can be extended with a length G2 longer than (G1). The length G2 may be arranged to be less than twice the distance G1 to minimize a decrease in the light emitting area. Accordingly, heat concentration in the region 75 between the first pad 71 and the second pad 81 may be improved.

FIG. 19 is an example of a lighting device having the semiconductor device of FIG. 4 .

Referring to FIG. 19 , the lighting device may include a circuit board 101 under the semiconductor device 100 . The circuit board 101 may supply power to the semiconductor device 100 . The circuit board 101 may include, for example, a printed circuit board (PCB). The printed circuit board includes, for example, at least one of a resin material PCB, a metal core PCB (MCPCB), and a flexible PCB (FPCB), and may be provided as a metal core PCB for heat dissipation.

The semiconductor device 100 is a device according to an embodiment, and includes a substrate 11, a light emitting structure 20 under the substrate 11, a first electrode layer 65 under the light emitting structure 20, and the light emitting structure 20. A second electrode layer 63 between the structure 20 and the first electrode layer 65, and first and second pads 81 connected to the circuit board 101 under the first and second electrode layers 63, 83) is placed. The semiconductor device 100 emits light generated by the light emitting structure 20 . The semiconductor device 100 is disposed on the circuit board 101 in a flip chip type.

Since the semiconductor device 100 is arranged as a flip chip, the first electrode layer 65 can reflect light traveling in a downward direction toward the substrate 11 . The area of the lower surface of the first electrode layer 65 may be larger than the area of the lower surface of the first conductive semiconductor layer 21 and may be larger than the sum of the lower surface and the lower side surface of the first conductive semiconductor layer 21 . The lower surface of the first conductive semiconductor layer 21 may be a surface facing the upper surface of the active layer 22 based on the drawing.

The circuit board 101 may include electrode patterns 111 and 113 spaced apart from each other. The electrode patterns 111 and 113 may correspond to the first and second pads 71 and 81 of the semiconductor device 100 . The first and second pads 71 and 81 of the semiconductor device 100 may be directly bonded to the electrode patterns 111 and 117 of the circuit board 100 or connected by bonding members 115 and 117, but is not limited thereto.

The lighting device reflects the light emitted from the light emitting structure 20 by the first and second electrode layers 63 and 65 and emits the light through the side surfaces of the substrate 11 and the first conductive semiconductor layer 21. . The substrate 11 may have a pattern 11A on an upper surface thereof to improve light extraction efficiency.

The lighting device may include a fluorescent film 121 on the semiconductor device 100 . The fluorescent film 121 may include at least one type of yellow phosphor, green phosphor, red phosphor, and blue phosphor, or two or more different types of phosphors, but is not limited thereto. The phosphor may be selectively formed from, for example, YAG, TAG, Silicate, Nitride, and Oxy-nitride-based materials. The light emitted from the light emitting device may be white, yellow, green, red, or blue light, but is not limited thereto.

The fluorescent film 121 may have an area equal to or larger than the area of the upper surface of the semiconductor device 100 . The fluorescent film 121 may be adhered to the substrate 11 with an adhesive, but is not limited thereto.

FIG. 20 is a modified example of FIG. 19 , and the lighting device may include a reflective member 131 on an outer circumference between the semiconductor device 100 and the circuit board 101 according to the embodiment. The reflective member 131 may re-reflect light leaking in a lateral direction through a side surface of the semiconductor device 100 . The reflective member 131 includes a non-metallic material and may be formed of a resin material such as silicon or epoxy. The reflective member 131 may include at least one of SiO ₂ , Al ₂ O ₃ , and TiO ₂ in a resin material. The reflective member 131 may be formed of a white resin material, but is not limited thereto.

21 is a modified example of FIG. 19 , in which a plurality of semiconductor elements 100 may be arranged on a circuit board 101 in the lighting device. Each of the plurality of semiconductor devices 100 is a semiconductor device according to an embodiment, and a detailed description thereof will be referred to the description of the first embodiment.

A reflective member 131 may be disposed on the plurality of semiconductor devices 100 and the circuit board 101 . The reflective member 131 may re-reflect light leaking in a lateral direction through the side surfaces of each of the plurality of semiconductor devices 100 . The reflective member 131 includes a non-metallic material and may be formed of a resin material such as silicon or epoxy. The reflective member 131 may include at least one of SiO ₂ , Al ₂ O ₃ , and TiO ₂ in a resin material. The reflective member 131 may be formed of a white resin material, but is not limited thereto.

The same or different fluorescent films 121 and 122 may be included on the plurality of semiconductor devices 100 .

The different fluorescent films 121 and 122 may, for example, convert light emitted from the light emitting structure 20 to a sun wavelength to emit white light having different color temperatures. Here, different color temperatures may provide different color temperatures of white light by differentiating relative intensities of light intensity in a blue region and light intensity in a green to red region (or yellow region) of the emission spectrum. For example, the color temperature may be adjusted according to the type or amount of the yellow phosphor. Looking at the color temperature of the light of the fluorescent films 121 and 122, white with a low color temperature corresponds to a relatively warm white, and white with a relatively high color temperature corresponds to a relatively cool white. . Light emitted through the fluorescent films 121 and 122 may emit warm white or cool white light. The warm white may have a color temperature of 4500K or less, and the cool white may have a cool white color temperature of 5000K to 6000K. As another example, three types of color temperatures may be emitted, and in this case, warm white, cool white, and pure white may be emitted. By mixing these color temperatures, the color rendering index (CRI) of light can be improved.

In the lighting device according to the embodiment, an optical lens may be further formed on the semiconductor element, and the optical lens may include a structure of a concave lens and/or a convex lens, and may control light distribution of light emitted from the semiconductor element. can be adjusted The lighting device may include a protection element that protects the semiconductor element. The protection element may be implemented as a thyristor, a zener diode, or transient voltage suppression (TVS).

Semiconductor devices according to embodiments include devices such as indoor lights, outdoor lights, streetlights, automobile lamps, headlights or taillights of moving or stationary devices, and indicator lights. At least one of a light guide plate, a diffusion sheet, and a prism sheet may be included on a light emission side of a semiconductor device according to an embodiment.

The semiconductor device described above is configured as a light emitting device package and can be used as a light source of a lighting system, for example, a light source of an image display device or a light source of a lighting device. When used as a backlight unit of an image display device, it can be used as an edge-type backlight unit or a direct-type backlight unit, and when used as a light source for a lighting device, it can be used as a lamp or bulb type, and can also be used as a light source for mobile terminals. may be

Light emitting devices using semiconductor devices include laser diodes in addition to the light emitting diodes described above. Like the light emitting device, the laser diode may include a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer having the above structure. In addition, an electro-luminescence phenomenon in which light is emitted when a current is passed after bonding a p-type first conductivity type semiconductor and an n-type second conductivity type semiconductor is used, but the directionality of the emitted light There is a difference between and phase. That is, the laser diode can emit light having a specific wavelength (monochromatic beam) with the same phase and in the same direction by using a phenomenon called stimulated emission and constructive interference, etc. Due to this, it can be used for optical communication, medical equipment, and semiconductor processing equipment.

A photodetector, which is a kind of transducer that detects light and converts its intensity into an electrical signal, can be exemplified as the light-receiving element. As such photodetectors, photocells (silicon, selenium), photoconductive devices (cadmium sulfide, cadmium selenide), photodiodes (eg, PDs having peak wavelengths in the visible blind spectral region or true blind spectral region), phototransistors , photomultiplier tube, photoelectric tube (vacuum, gas filled), IR (Infra-Red) detector, etc., but the embodiment is not limited thereto.

In addition, a semiconductor device such as a photodetector may be fabricated using a direct bandgap semiconductor having excellent light conversion efficiency. Alternatively, photodetectors have various structures, and the most common structures include a pin type photodetector using a p-n junction, a Schottky type photodetector using a Schottky junction, and a Metal Semiconductor Metal (MSM) type photodetector. there is.

Like a light emitting device, a photodiode may include a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer having the above-described structure, and has a pn junction or pin structure. The photodiode operates by applying reverse bias or zero bias, and when light is incident on the photodiode, electrons and holes are generated and current flows. In this case, the size of the current may be substantially proportional to the intensity of light incident on the photodiode.

A photovoltaic cell or solar cell is a type of photodiode and can convert light into electric current. A solar cell, like a light emitting device, may include a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer having the above structure.

In addition, it can be used as a rectifier of an electronic circuit through the rectification characteristics of a general diode using a p-n junction, and can be applied to an oscillation circuit by being applied to a microwave circuit.

In addition, the above-described semiconductor device is not necessarily implemented as a semiconductor and may further include a metal material in some cases. For example, a semiconductor device such as a light receiving device may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, or As, and may be implemented using a p-type or n-type dopant. It may be implemented using a doped semiconductor material or an intrinsic semiconductor material.

Although the above has been described with reference to the embodiments, this is only an example and does not limit the present invention, and those skilled in the art to which the present invention belongs will not deviate from the essential characteristics of the present embodiment. It will be appreciated that various variations and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

100: semiconductor element 11: substrate
20: light emitting structure 21: first conductivity type semiconductor layer
22: active layer 23: second conductivity type semiconductor layer
51,55: insulating layer 61: conductive layer
63: second electrode layer 65: first electrode layer
67: first electrode 101: circuit board
121,122: fluorescent film

Claims (18)

A first conductive semiconductor layer having a central region and a first region around the central region that is lower than the height of the top surface of the central region, an active layer disposed on the central region of the first conductive semiconductor layer, and disposed on the active layer A light emitting structure including a second conductive type semiconductor layer;
a plurality of first electrodes disposed in a first region of the first conductive semiconductor layer and electrically connected to the first conductive semiconductor layer;
a first electrode layer disposed on the light emitting structure and the first electrode and electrically connected to the first electrode;
a second electrode layer disposed between the first electrode layer and the second conductive semiconductor layer and electrically connected to the second conductive semiconductor layer;
a first insulating layer disposed between the first electrode layer and the second electrode layer; and
A first pad and a second pad are provided on the first electrode layer,
The first region of the first conductive semiconductor layer is disposed around the central region in a first axis direction and a second axis direction orthogonal to each other;
The plurality of first electrodes are disposed in the same axial direction as the first and second axial directions in which the first region is disposed and have the same length;
The first pad and the second pad each include a first concave portion and a second concave portion on upper surfaces,
The semiconductor device of claim 1 , wherein a depth of the second concave portion is deeper than a depth of the first concave portion. The semiconductor device of claim 1 , wherein the plurality of first electrodes disposed in the first axis direction and the second axis direction are connected to each other. 3 . The semiconductor device of claim 2 , wherein the first electrodes disposed in the first axis direction and the second axis direction are continuously connected around a central region of the first conductivity type semiconductor layer. 3 . The method of claim 2 , wherein the first insulating layer comprises the plurality of first electrodes and the first conductive type at a corner of the first region of the first conductive type semiconductor layer where the first axial direction and the second axial direction are orthogonal to each other. A semiconductor element disposed between semiconductor layers. 3 . The semiconductor device of claim 2 , wherein the plurality of first electrodes are spaced at equal intervals in different axial directions from vertices of corner regions of the first conductive type semiconductor layer. The semiconductor device of claim 5 , wherein a length of the first electrode disposed in the first axis direction or the second axis direction is 1/2 or more of the length of the first region in the first axis direction or the second axis direction. . The semiconductor device of claim 6 , wherein the plurality of first electrodes are rotationally symmetric about a central axis of the light emitting structure. The semiconductor device according to any one of claims 1 to 5, wherein the first electrode layer includes a contact portion disposed on the first region and in contact with the first conductive type semiconductor layer. The semiconductor device according to claim 8 , wherein the contact portion of the first electrode layer is disposed inside and outside the first electrode. According to claim 9,
And a second insulating layer disposed on the first electrode layer,
The first insulating layer is connected to the second insulating layer on the first region,
The first insulating layer and the second insulating layer are spaced apart from an outermost edge of the first conductive type semiconductor layer. According to any one of claims 1 to 5, wherein the side of the light emitting structure is inclined,
An outer portion of the first insulating layer is disposed between the first electrode and the side surface of the light emitting structure. The semiconductor device according to any one of claims 2 to 5, wherein an area of the lower surface of the first electrode layer is larger than an area of the lower surface of the first conductive type semiconductor layer. delete The semiconductor device of claim 11 , wherein the first pad has a plurality of first protrusions protruding in a direction of the first electrode layer, and the second pad has a plurality of second protrusions protruding in a direction of the second electrode layer. 6. The semiconductor device according to any one of claims 1 to 5, wherein the first electrode layer has a branch electrode extending to a region between the first pad and the second pad. The semiconductor device according to any one of claims 1 to 5, further comprising a substrate disposed below the first conductivity type semiconductor layer, wherein the substrate is formed of a semiconductor of the same material as the first conductivity type semiconductor layer. . The method according to any one of claims 1 to 6, further comprising a conductive layer between the second electrode layer and the second conductive semiconductor layer,
The first electrode layer and the second electrode layer reflect light,
The conductive layer is a semiconductor device having a material different from that of the first electrode. circuit board;
a plurality of semiconductor elements arranged on the circuit board; and
An electrode pattern electrically connecting the plurality of semiconductor elements to the circuit board,
The semiconductor device,
a substrate with a pattern;
The light emitting structure disposed on the substrate, the light emitting structure, a first conductivity type semiconductor layer having a central region and a first region around the central region that is lower than the height of the upper surface of the central region, the first conductivity type semiconductor layer an active layer disposed on the central region, and a second conductive type semiconductor layer disposed on the active layer;
a plurality of first electrodes disposed in a first region of the first conductive semiconductor layer and electrically connected to the first conductive semiconductor layer;
a first electrode layer disposed on the light emitting structure and the first electrode and electrically connected to the first electrode;
a second electrode layer disposed between the first electrode layer and the second conductive semiconductor layer and electrically connected to the second conductive semiconductor layer;
a first insulating layer disposed between the first electrode layer and the second electrode layer; and
At least one pad on the first electrode layer,
The first region of the first conductive semiconductor layer is disposed around the central region in a first axis direction and a second axis direction orthogonal to each other;
The plurality of first electrodes are disposed with the same length along the same axial direction as the first and second axial directions in which the first region is disposed,
The length of the plurality of first electrodes in the first axis direction and the second axis direction is 1/2 or more of the length of the substrate,
The first electrode layer has a lower surface area larger than that of the first conductive semiconductor layer.
The at least one pad includes a first pad and a second pad,
The first pad and the second pad each include a first concave portion and a second concave portion on upper surfaces,
A depth of the second concave portion is disposed deeper than a depth of the first concave portion.

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